TECHNICAL FIELD
[0001] The present invention relates to a refrigerator utilizing a non-contact sensor.
BACKGROUND ART
[0002] In recent years, with an increase in demand for a high capacity refrigerator, a refrigerator
capable of improving volume efficiency by reducing invalid spaces and a refrigerator
having various layouts from a viewpoint of usability have been released.
[0003] In such refrigerators, in order to detect an inside temperature, an inside air temperature
is conventionally measured by a thermistor and the like. For example, when a hot food
is put in the refrigerator, the inside air temperature warmed by this hot food is
measured by a plurality of thermistors installed inside the refrigerator, to thereby
adjust a cooling quality. However, in such a kind of refrigerator, an actual temperature
of the food is not measured, and therefore it is uncertain whether the food can be
actually cooled. Therefore, in cooling the food, the food is cooled to a target temperature
while cooling the circumference, thus involving a problem that time is required for
cooling the food itself to a target temperature. Accordingly, for example by installing
a non-contact infrared sensor inside refrigerator, or by using a load sensor attached
under a case for arranging food to directly measure the temperature of the food, the
temperature of an actual food is detected and cooling operation is performed (for
example, refer to Patent Documents 1 and 2).
[0004] Conventional refrigerators of Patent Documents 1 and 2 will be described below with
reference to the drawings.
[0005] FIG. 7 is a side vertical section view of a refrigerator described in Patent Document
1, and FIG. 8 is a partially expanded side section view thereof, wherein inside of
refrigerator body 1 formed of a thermally insulated box body is set as a storage space,
with refrigerating room 2 disposed in an uppermost section, vegetable room 6 disposed
in a lower section, and freezing room 8 disposed in a lowermost section, respectively,
independently of one another, and switching room 9 and an ice making room (not shown)
disposed next to each other with a thermally insulated partition wall interposed therebetween
between refrigerating room 2 and vegetable room 6, and an exclusive door provided
to a front opening of each storage room, to openably close the opening.
[0006] Freezing room 8, switching room 9, freezing cooler 14 such as an ice making room,
and cold air ventilation fan 16 for circulating cold air generated by freezing cooler
14 in the storage room are disposed in a back part of vegetable room 6. Further, refrigerating
cooler 15 for cooling refrigerating room 2 and vegetable room 6 and a fan (not shown)
are provided to a front position of freezing cooler 14. Then, refrigerant is alternately
or simultaneously flown to freezing and refrigerating coolers 14 and 15 by driving
compressor 17 installed in a lower part of a main body and by controlling a switch
of a flow channel switching valve (not shown) of the refrigerant. Then, the cooled
cold air is sent to each storage room at a frozen temperature zone side and a refrigeration
temperature zone side by cold air ventilation fan 16, to thereby control the temperature
to be cooled to a predetermined temperature.
[0007] Cold air of a low temperature discharged from freezing cooler 14 is branched into
freezing room 8, the ice making room, and switching room 9 by cold air ventilation
fan 16, which is then sent through an exclusive ventilation duct and cooled.
[0008] Under control of switching room 9, cold air is blown-out into each room from cold
air blow-out port 20, and the temperature of food 21, being a load cooled by this
cold air, is detected by infrared sensor 28 attached to a top panel, and by driving
a freezing cycle to set the temperature to a previously set temperature and by performing
opening and closing control of cold air dumper 32 installed near cold air blow-out
port 20, introduction amount of cold air into each room is adjusted so that the temperature
of food 21, being a foodstuff, is set to a predetermined temperature.
[0009] Thus, by detecting a surface temperature of food 21, being a detecting object, by
infrared sensor 28, and by performing only a required amount of cooling drive when
required, efficient cooling drive control is performed.
[0010] Next, another conventional refrigerator will be described.
[0011] FIG. 9 is a perspective view showing inside of a storage room of the refrigerator
described in Patent Document 2, and FIG. 10 is a front view showing inside of a freezing
room of the refrigerator described in Patent Document 2.
[0012] As shown in the figure, in another conventional refrigerator, whether storing of
food, namely, charging load is present or absent is decided based on a temperature
variation of load temperature sensor 39 disposed at a bottom of freezing room 8. When
it is determined that the load exists, the temperature of the food and a size of the
load are detected by load temperature sensor 39. Then, based on the detected temperature
and variation of the temperature, when it is determined that the load exists, rapid
freezing operation is started by the cold air flown into freezing room 8.
[0013] With this structure, unnecessary rapid freezing operation can be controlled to be
avoided, by deciding a rapid freezing time according to the size of the load of the
stored food.
[0014] Thus, according to a conventional technique, the temperature of the food, being the
detecting object, is detected by load temperature sensor 39 provided to lower part
of case 41 of a food mounting portion, then automatic rapid freezing is started or
ended, and only required amount of cooling drive is performed when required, to thereby
perform efficient cooling drive control.
[0015] However, in such a conventional structure according to Patent Document 1, infrared
sensor 28 installed on a ceiling part of switching room 9 detects the temperature
of food 21 when a door is closed, and cold air generated by freezing cooler 14 is
controlled by opening and closing cold air dumper 32 based on the detected temperature
of food 21 so that the introduction amount of the cold air into each room is adjusted.
Thus, the temperature of food 21 is controlled to a predetermined set temperature.
However, when the door is opened, detection of infrared sensor 28 strays from food
21 and is directed toward a thermally insulated partition portion on a projected surface.
The temperature of the thermally insulated partition portion is different from the
temperature of switching room 9 under an influence of the temperature caused by heat
conduction from vegetable room 6 in the lower part. Therefore, infrared sensor 28
detects the temperature different from the temperature of the food cooled corresponding
to the temperature of switching room 9. In other words, a part detected by infrared
sensor 28 is subjected to sudden temperature variation when the door is opened. Specifically,
when conventional switching room 9 is set to a frozen temperature and the door is
opened only for confirming food 21 stored in switching room 9, infrared sensor 28
detects the temperature erroneously as the temperature at the time of putting in the
food 21, and therefore cooling is started, thus involving a problem that switching
room 9 is excessively cooled and useless energy is required.
[0016] In order to solve the above-described problems, there is a method of providing a
switch function for detecting open/close of a door. However, during open/close of
the door, interlocking control is necessary between the detection by infrared sensor
28 and switch control. Therefore, there is a problem that a complicated control is
invited and an erroneous operation factor is possibly increased.
[0017] Further, when droplets are adhered to a leading end portion of infrared sensor 28
due to dew condensation water, etc, infrared sensor 28 detects the droplets without
detecting food 21. Therefore, for example, there is also a method of providing a shutter
mechanism in a sensor part of infrared sensor 28, for preventing dew condensation
of a detected part of the leading end of the sensor due to flow of warm air from outside
when the door is opened or closed. However, the shutter mechanism has a complicated
mechanical structure, and therefore there is a high possibility that the erroneous
operation factor is increased. Particularly, in the storage room of the refrigerator
set at a low temperature, a problem such as reduction of reliability and malfunction
of the mechanical structure is easily generated due to deterioration of lubricity
of lubricating oil, in a case of the aforementioned complicated mechanical structure,
and such a problem is particularly remarkable in a room set to a frozen temperature
zone. Further, there is also a problem that trouble in movable action is generated
when the dew condensation is frozen or by frost, etc.
[0018] Moreover, in another conventional structure of Patent Document 2, although there
is a constant effect, it is insufficient for energy saving which is an interest of
a market toward global environment in recent years or demands for improving freshness
keeping performance of the refrigerator.
[0019] This is because in order to perform long-term storage of the food while maintaining
the freshness keeping performance of the food, it is important to rapidly pass a temperature
zone of 0°C to -5°C called a maximum frozen crystal creating range when the food is
cooled so that cell destruction is prevented, therefore rapid freezing operation is
performed by indirect cooling by cold air, and accordingly there is a limit in increasing
a speed for passing the maximum frozen crystal creating range of 0°C to -5°C.
[0020] Further, when the rapid freezing operation is performed, introduction amount of the
cold air into freezing room 8 is increased by setting a compressor and a cold air
ventilation fan in a continuous operation mode to be rapidly frozen. Therefore, since
freezing capacity of the refrigerator is enhanced for a certain period of time, power
input of the refrigerator is considerably increased, thus requiring further use of
energy, although a freezing rate is more increased than normal cooling. Therefore,
the rapid freezing operation with energy saving taken into consideration is hardly
performed.
[0021] Further, in the method of detecting the temperature of the food directly, the temperature
of case 41 in contact with the food is detected by load temperature sensor 39 during
rapid freezing, by disposing load temperature sensor 39 at the bottom of case 41,
being a container in which foods are arranged, according to another conventional example
described in Patent Document 2. This makes it difficult to rapidly detect the temperature
of the food itself, and the temperature of the food is detected for the first time,
only when heat conduction occurs from the food to case 41, and the temperature of
the food and the temperature of the case itself are almost identical to each other.
Therefore, there is a problem that detection time is delayed.
[0022] Further, the cooling time is required for not only the food, but also the load of
the food other than the food desired to be cooled contained in case 41. In this case,
as to a rapid freezing time, continuous operation mode is set for actual food 21 only,
resulting in allowing useless cooling energy to occur.
[0023] Document
JP 2002 235976 A discloses a refrigerator wherein in a thermally insulated room food can be cooled
to a predetermined temperature. Above the area where the food can be placed an infrared
sensor is installed for detecting the temperature of newly inserted food which has
not yet been cooled. The food is placed on a specific mark on a vessel in the insulated
room. The infrared sensor is arranged to detect the food in a certain detection area.
The detection result is evaluated to control cooling action of the refrigerator. Specifically,
when the temperature detected by the infrared sensor has reached a predetermined temperature
cooling is stopped.
[0024] Document
JP 2003 075050 A discloses a refrigerator having a refrigeration space in the form of an insulated
box wherein a quick freezing compartment is defined. Food to be cooled can be placed
in the quick freezing compartment. A damper is disposed on the rear face of the compartment,
and when weak-frozen food is accommodated in the compartment the damper is opened
to make cold air forcibly flow in so as to execute a quick freezing below the maximum
ice crystal forming range. In addition, a heater is provided that can be energised
under predetermined conditions so that the interior can be kept within the weak freezing
temperature.
[0025] Document
JP 2005 201533 A discloses a storage device which is adapted for storing minced meat, thin-sliced
meat, slices of fish or the like as frozen food. Any damage of the tissue should be
avoided. To this end, a freezing speed is controlled to 0.1 to 1.0°C/min, and in a
preservation period the temperature of the food is controlled to lie in the range
of -2°C to -5°C.
[0026] Document
US 6 526 766 B1 discloses a refrigerator according to the preamble of claim 1 and describes a method
of operating the refrigerator, wherein in an insulated room at a certain height from
a base surface a temperature controller is arranged which is adapted for controlling
running of the compressor and a fan inside the refrigerator for obtaining a large
quantity of cooled air for quickly cooling of foods newly incorporated in the insulated
box. Quick cooling can be initiated by the user and a quick cooling time can be set.
Specifically, the temperature inside the refrigerator is monitored and cooling activity
of the refrigerator is controlled to compensate for warm food stored in the refrigerator.
Temperature settings are displayed to inform the user of the refrigerator.
[0027] Document
JP 2002 228353 A discloses a cooling cooking chamber, wherein an infrared sensor is arranged above
a space where food to be cooled can be placed to execute the cooling cooking. The
infrared sensor can monitor the temperature of the food when a quick cooling operation
is conducted. The structure of the infrared sensor serves for precise detection of
the infrared rays to obtain the cooling cooking with appropriate conditions.
[0028] Document
JP 6 185847 A discloses a refrigerator, wherein different freezing chambers are arranged to obtain
different freezing conditions. Inside a particular freezing room which is provided
with a metal plate on a bottom thereof a temperature sensor is arranged, and output
signals of the temperature sensor are fed to a control means which automatically starts
a rapid freezing operation based on the output of the temperature sensor, i.e. based
on the condition that warm food has been stored in the freezing chamber concerned.
[0029] In order to solve the above-described problems, of the prior art the present invention
has been made, and the present invention provides a refrigerator capable of eliminating
erroneous detection of a non-contact sensor by a simple method without using a complicated
method, and also capable of performing efficient cooling drive while saving energy,
by having the non-contact sensor that performs detection of temperature in a storage
room of the refrigerator with higher accuracy. Further, the present invention provides
the refrigerator capable of rapidly starting automatic rapid cooling for the food
put into the refrigerator and capable of further improving energy saving for performing
rapid cooling that realizes further energy saving and also achieving good usability.
[Patent Document 1] Unexamined Japanese Patent Publication No. 2007-212053
[Patent Document 2] Japanese Patent No. 3454522
DISCLOSURE OF THE INVENTION
[0030] According to the present invention this object is accomplished by a refrigerator
as set out in the appended claims.
[0031] The refrigerator according to the present invention comprises a food mounting portion
having a heat storage function; a storage room in which a non-contact sensor for detecting
a surface temperature of a food placed on the food mounting portion is installed;
cooling means for cooling the storage room; and rapid freezing control means configured
to carry out rapid freezing control to cool the storage room with a high cooling capacity,
wherein the food mounting portion provides a heat storage function to support rapid
freezing to deprive heat from the food brought into contact with the food mounting
portion and wherein the rapid freezing control is automatically started by the rapid
freezing control means for cooling with the high cooling capacity when the temperature
of the food detected by the non-contact sensor is higher than a previously set start
temperature. The rapid freezing control is automatically stopped at a time point at
which the temperature of the food detected by the non-contact sensor reaches a previously
set end temperature.
[0032] With this structure, the temperature of the food is detected by the sensor for detecting
the temperature in a non-contact state and the rapid freezing control is automatically
started, and when the temperature reaches an end point, an operation is rapidly moved
to a normal cooling operation. Therefore, automatic rapid cooling is speedily started
for the food put into the refrigerator, and rapid cooling is achieved by directly
depriving heat by heat conduction, because the food mounting portion has the heat
storage function and such a food mounting portion cooled to a previously set frozen
temperature zone is brought into contact with the food. Therefore, even in a case
where the rapid freezing is controlled, continuous driving time of the compressor
and the cold air ventilation fan can be tremendously shortened, and the rapid cooling
capable of realizing further energy saving is achieved.
[0033] Further, from the viewpoint of preserving the food, the food mounting portion has
the heat storage function for controlling rapid freezing of the present invention,
thereby making it possible to perform heat transmission by introduction of the cold
air by controlling rapid freezing and by heat conduction from the food mounting portion
having the heat storage function, and realizing rapid cooling by using both the heat
transmission and heat conduction. Therefore, a transit time of the maximum frozen
crystal creating range of 0°C to -5°C that greatly affects the freshness particularly
in a case of a frozen storage, can be further shortened. Then, by passing the maximum
frozen crystal creating range in a short time, drips from the food can be reduced
when the food is defrosted, thus making it possible to preserve the food without losing
the freshness and taste. Therefore, a high storage quality of the food can be achieved.
[0034] As described above, the refrigerator of the present invention is capable of eliminating
the erroneous detection of the non-contact sensor by a simple method without using
a complicated method. This contributes to realizing an efficient cooling drive of
the refrigerator and rapid cooling that attains energy saving, and also improving
the storage quality of the frozen food. Thus, the refrigerator with higher storage
quality that attains further energy saving can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035]
FIG. 1 is a front view of a refrigerator according to Example 1 of the present disclosure
and Embodiment 1 of the present invention.
FIG. 2 is a side section view of the refrigerator according to the Example 1 of the
present disclosure and Embodiment 1 of the present invention.
FIG. 3 is a partially expanded side section view of an upper stage freezing room according
to Example 1 of the present disclosure.
FIG. 4 is a partially expanded side section view of an upper stage freezing room of
a refrigerator according to Embodiment 1 of the present invention.
FIG. 5 is a partially expanded side section view of a refrigerator according to Embodiment
2 of the present invention.
FIG. 6 is a side section view of a refrigerator according to Embodiment 3 of the present
invention.
FIG. 7 is a side section view for illustrating a refrigerator according to a conventional
art.
FIG. 8 is a partially expanded side section view for illustrating a refrigerator according
to the conventional art.
FIG. 9 is a perspective view showing inside of a storage room of a refrigerator according
to another conventional art.
FIG. 10 is a front view showing inside of a freezing room of a refrigerator according
to another conventional art.
REFERENCE MARKS IN THE DRAWINGS
[0036]
102 Refrigerating room (reserve room)
103, 203, 303 Upper stage freezing room (storage room)
105, 205, 305 Lower stage freezing room (storage room)
107 Cooler
110 First thermally insulated partition portion (thermally insulated partition portion)
121, 221, 421 Food
127, 227, 427 Case (upper stage freezing room)
128, 228, 328, 425 Infrared sensor (non-contact sensor)
133, 233 Mark
142, 242, 426 Cool storage medium (food mounting portion)
432 First discharge port
433 Second discharge port
434 Discharge duct
435 Downward discharge port
PREFERRED EMBODIMENTS
[0037] The present invention as defined in claim 1 provides, amongst others, the refrigerator,
including:
a storage room in which a non-contact sensor for detecting a surface temperature of
a food placed on a food mounting portion is installed;
cooling means for cooling the storage room; and
rapid freezing control means for cooling the storage room with a high cooling capacity,
wherein
the food mounting portion has a heat storage function, a rapid freezing control is
automatically started by the rapid freezing control means for cooling with the high
cooling capacity if the temperature detected by the non-contact sensor is higher than
a previously set start temperature, and the rapid freezing control by the rapid freezing
control means is stopped at a time point at which the temperature reaches a previously
set end temperature.
[0038] With this structure, the temperature of the food is detected by the sensor for detecting
the temperature in a non-contact state and the rapid freezing control is automatically
started, and when the temperature reaches an end point, an operation is rapidly moved
to a normal cooling operation. Therefore, automatic rapid cooling is speedily started
for the food put into the storage room, and rapid cooling is achieved by directly
drawing heat by heat conduction, because the food mounting portion has the heat storage
function and such a food mounting portion cooled to a previously set frozen temperature
zone is brought into contact with the food. Therefore, even in a case where the rapid
freezing is controlled, continuous driving time of the compressor and the cold air
ventilation fan can be tremendously shortened, and the rapid cooling capable of realizing
further energy saving is achieved.
[0039] Further, from the viewpoint of preserving the food, the food mounting portion has
the heat storage function for controlling rapid freezing of the present invention,
thereby making it possible to perform heat transmission by introduction of the cold
air by controlling rapid freezing and by heat conduction from the food mounting portion
having the heat storage function, and realizing rapid cooling by using both the heat
transmission and heat conduction. Therefore, the transit time of the maximum frozen
crystal creating range of 0°C to -5°C that greatly affects the freshness particularly
in a case of a frozen storage, can be further shortened. Then, by passing the maximum
frozen crystal creating range for a short time, drips from the food can be reduced
when the food is defrosted, thus making it possible to preserve the food without losing
the freshness and taste, thereby achieving a high storage quality of the food.
[0040] As described above, improvement of the cooling capacity is carried out automatically,
and therefore the refrigerator can be cooled by a cooling drive as needed. Particularly,
as a countermeasure against the increase of the temperature inside of the room under
an influence of charging the load, or in order to cool the load desired to be rapidly
frozen, driving time of the refrigerator can be shortened out of 24 hours driving
time, by short time cooling with high cooling capacity, rather than slowly cooling
the load by driving a compressor with a medium rotation of about 40 Hz as conventional.
Therefore, power consumption can be reduced, and also an exhaust quantity of greenhouse
effect gas can be effectively restrained, which is a factor of worsening the global
environment.
[0041] Further, although conventionally rapid freezing is controlled manually for the food
desired to be frozen rapidly, the rapid freezing is controlled automatically in the
present invention. Therefore, troublesome operation of controlling rapid freezing
after putting in the food can be eliminated. In some of the refrigerators of recent
years, in order to operate rapid freezing, the rapid freezing control needs to be
selected and determination motion needs to be selected. Therefore, the rapid freezing
operation itself is considered to be troublesome. However, according to the present
invention, the rapid freezing is automatically controlled and cooling operation of
the food is controlled by automatic cooling drive with high capacity. Therefore, a
case that a user forgets to control rapid freezing does not occur.
[0042] Further, when the user comes back home from shopping and stores the food in the refrigerator
for keeping fresh food such as meat in a freezer, the temperature inside the refrigerator
is increased under an influence of open/close of the door. In this case, conventionally
rapid freezing is not controlled automatically, and therefore time is required for
cooling the food with low cooling capacity. However, according to the present invention,
the rapid freezing can be automatically controlled when the temperature is high, depending
on the temperature detected by the non-contact sensor. Therefore, the food can be
rapidly cooled without requiring time, with high cooling capacity. As a result, the
cooling time for cooling the food can be shortened and degradation of the freshness
can be suppressed, because the temperature rise of the food itself can be suppressed
by short time cooling.
[0043] Further, the rapid freezing control is automatically canceled when the food is frozen,
and therefore, unlike the conventional art, wasteful energy consumption by unnecessary
cooling drive after freezing can be eliminated. Moreover, in some of the conventional
refrigerators, transition from a latent heat change to a sensible heat change of the
food is detected and completion of freezing is determined based on the detection.
However, in a case of showing equivalent change amount from the latent heat change
to the sensible heat change depending on a size of the food, the completion of the
freezing is hardly determined. However, according to the present invention, the temperature
of the food itself is detected, and therefore freezing can be surely determined. Therefore,
unlike the conventional art, complicated differential calculation control specification
needs not to be constructed for calculating a change ratio of the food.
[0044] Further, in addition to the above-described invention, the present invention provides
the refrigerator, wherein the non-contact sensor is the infrared sensor, and is provided
in a storage room wall surface in an opposite side to the food mounting portion, and
the storage room is a freezing room which is settable only in a frozen temperature
zone.
[0045] With this structure, generally the infrared sensor has characteristics that detection
accuracy is deteriorated as the infrared sensor is installed far away from a temperature
zone where the accuracy is set highest. However, since the storage room in which the
infrared sensor is installed corresponds to the freezing room, the temperature can
be previously set highest in the vicinity of the frozen temperature zone, and is not
set in other temperature zone. Therefore, the temperature of the food can be always
detected with good accuracy, and further accurate start and end of the rapid freezing
operation can be controlled. Thus, the rapid freezing realizing further energy saving
can be controlled.
[0046] Further, by directly detecting a food temperature, the temperature of the food desired
to be rapidly frozen can be detected in real time, thus making it possible to rapidly
and accurately start and end the rapid freezing control, and control the rapid freezing
that realizes further energy saving.
[0047] Further, in addition to the above-described invention, the present invention provides
the refrigerator, wherein the temperature zone in which the rapid freezing control
is automatically started by the rapid freezing control means includes a detection
temperature between 0°C and -5°C in the temperature detected by the infrared sensor.
[0048] With this structure, the temperature can be controlled, by passing the maximum frozen
crystal creating range of 0°C to -5°C for a short time, which has a great influence
on frozen storage of the food. Therefore, it is possible to suppress the deterioration
of the taste of the food and the deterioration of quality by suppressing a destruction
of a tissue structure. As a result, drips from the food can be suppressed at the time
of defrosting, and therefore the food can be preserved without losing the freshness
and taste.
[0049] Preferred embodiments will be described below with reference to the drawings. Note
that the present invention is not limited by the embodiments.
(Example 1)
[0050] FIG. 1 is a front view of a refrigerator according to Example 1 of the present disclosure.
FIG. 2 is a side section view of the refrigerator according to Example 1 of the present
disclosure. FIG. 3 is a partially expanded side section view of an upper stage freezing
room according to Example 1 of the present disclosure.
[0051] As shown in FIGS. 1 to 3, refrigerator main body 101 is a thermally insulated box
body composed of outer box 124 made of metal (such as iron plate) opening frontward,
inner box 125 made of hard resin (such as ABS), and made of urethane heat insulating
material 126 foamed and filled between outer box 124 and inner box 125, the thermally
insulated box body including:
refrigerating room 102 provided at an upper part of the main body;
upper stage freezing room 103 provided below the refrigerating room;
ice making room 104 provided below refrigerating room 102 and in parallel with upper
stage freezing room 103;
vegetable room 106 provided at a lower part of the main body; and
lower stage freezing room 105 provided between upper stage freezing room 103 and ice
making room 104 provided in parallel with each other, and vegetable room 106. Front
face parts of upper stage freezing room 103, ice making room 104, lower stage freezing
room 105, and vegetable room 106 are respectively openably closed by drawer type doors
103a, 104a, 105a, and 106a respectively, and a front face of refrigerating room 102
is openably closed by door 102a (not shown), being a double-hinged door 102a.
[0052] Refrigerating room 102 is set normally between 1°C and 5°C for storing under freeze
while setting an ice-free temperature to a lower limit. It is often the case that
vegetable room 106 is set between 2°C and 7°C which is a set temperature equal to
or slightly higher than refrigerating room 102. If it is set to a low temperature,
it is possible to maintain a freshness of a leaf vegetable for a long period. Upper
stage freezing room 103 is normally set between -22 and -18°C for storing under freeze.
However, depending on a frozen storage state preferred by a user, upper stage freezing
room 103 can also be set to a soft frozen temperature zone around -7°C in which labor
in cooking such as defrosting can be saved. Then, in order to further improve the
frozen storage state, the temperature is sometimes set in a low temperature frozen
temperature zone in a range of -30°C to -25°C which is further lower than -22°C to
-18°C, being a normal frozen temperature zone. The temperature of lower stage freezing
room 105 is normally set in a range of -22°C to -18°C for controlling frozen storage.
However, in order to further improve the frozen storage state, the temperature is
sometimes set in a low temperature frozen temperature zone in a range of -30°C to
-25°C which is further lower than -22°C to -18°C, being a normal frozen temperature
zone.
[0053] Insides of refrigerating room 102 and vegetable room 106 are set to plus temperatures,
and therefore are called refrigeration temperature zones. Further, insides of upper
stage freezing room 103, lower stage freezing room 105, and ice making room 104 are
set to minus temperatures, and therefore are called frozen temperature zones.
[0054] A top panel portion of refrigerator main body 101 is recessed stepwise toward a back
face side of refrigerator main body 101, to form machine room 119 therein, and is
constituted of a first top panel portion and a second top panel portion. Refrigerant
is enclosed in a freezing cycle formed by successively annularly connecting compressor
117 disposed in the stepwise recessed portion, a drier (not shown) for removing moisture,
a capacitor (not shown), a heat radiating pipe (not shown) for heat radiation, capillary
tube 118, and cooler 107, so that cooling drive is carried out. In recent years, flammable
refrigerant is frequently used as the refrigerant, in consideration of environment
protection. Note that in a case of the freezing cycle in which a three-way valve and
a changeover valve are used, such functional components can be disposed within the
machine room.
[0055] Further, refrigerating room 102, ice making room 104, and upper stage freezing room
103 are partitioned by first thermally insulated partition portion 110.
[0056] Further, ice making room 104 and upper stage freezing room 103 are partitioned by
second thermally insulated partition portion 111.
[0057] Further, ice making room 104, upper stage freezing room 103, and lower stage freezing
room 105 are partitioned by third thermally insulated partition portion 112.
[0058] Second thermally insulated partition portion 111 and third thermally insulated partition
portion 112 are components assembled after foaming refrigerator main body 101. Therefore,
polystyrene foam is normally used as a heat insulating material. However, hard urethane
foam may be used for improving heat insulating performance and rigidity, and in addition,
further thinner compartment structure may be achieved by inserting a vacuum heat insulating
material having high heat insulating property.
[0059] Further, by thinning or eliminating second thermally insulated partition portion
111 and third thermally insulated partition portion 112 by securing an operation part
of a door frame, a cooled air passage can be secured, to thereby improve cooling capacity.
In addition, a central part of second thermally insulated partition portion 111 and
third thermally insulated partition portion 112 is hollowed out to form an air passage,
thereby achieving reduction of materials.
[0060] Further, lower stage freezing room 105 and vegetable room 106 are partitioned by
fourth thermally insulated partition portion 113.
[0061] Cooling room 123 is provided on a back face of refrigerator main body 101, and in
cooling room 123, cooler 107 typically generating cold air of fins and flat heat transfer
tubes is vertically disposed in upper and lower directions on the back face of lower
stage freezing room 105 including a backward region of second and third thermally
insulated partition portions 111 and 112, being thermally insulated partition walls.
Further, cooler 107 is made of aluminum or copper.
[0062] Cold air ventilation fan 116 is disposed in the vicinity (for example upper space)
of cooler 107, for sending the cold air generated by cooler 107 to each storage room
of refrigerating room 102, ice making room 104, upper stage freezing room 103, lower
stage freezing room 105, and vegetable room 106, by forcible convention system. In
addition, radiant heater 134 made of glass tube, being a defrosting device for defrosting
a frost adhered to cooler 107 and cold air ventilation fan 116 during cooling operation,
is provided to a lower space of cooler 107. The defrosting device is not particularly
limited, and a pipe heater attached firmly to cooler 107 may also be used, other than
radiant heater 134.
[0063] Although cold air ventilation fan 116 is sometimes directly disposed in inner box
125, it is disposed in second thermally insulated partition portion 111 assembled
after foaming, and block machining is applied to components, to thereby achieve reduction
of a manufacturing cost.
[0064] Next, the structure of upper stage freezing room 103 will be described in which infrared
sensor 128, being a non contact sensor is installed.
[0065] As shown in FIG. 3, infrared sensor 128 for detecting the temperature of food 121
is installed in first thermally insulated partition portion 110, being the top panel
portion of upper stage freezing room 103, toward a direction (lower direction in a
case of this example) in which the adjacent storage rooms exist on a projection surface
of a surface detected by infrared sensor 128. A discharge port (not shown) and a return
port (not shown) of the cold air are provided on a back face upper part of upper stage
freezing room 103. The cold air generated by cooler 107 is discharged from the discharge
port, and the cold air circulated through upper stage freezing room 103 is returned
again to cooling room 123. As shown by this example, by installing infrared sensor
128 within the thermally insulated partition portion, infrared sensor 128 is hardly
affected by the cold air discharged from the discharge port, and therefore detection
accuracy can be improved. Further, a leading end portion of infrared sensor 128 is
positioned inside or the same surface of/as the surface of the thermally insulated
partition portion, thereby preventing foreign matters from adhering to a detection
part of infrared sensor 128 even in a case of putting large volume of food 121 into
the storage room or during cleaning. Therefore, erroneous operation of the detection
is not invited. Further, no catch by inward protrusions in the refrigerator occurs
during cleaning, and therefore missing or deviation, etc, of the components in a detecting
direction due to addition of an excessive force can be prevented. Moreover, there
is no protrusion inward, and therefore inner capacity is not reduced so that the capacity
of the refrigerator is secured.
[0066] Further, case 127 in the storage room detected by infrared sensor 128 is provided
with mark 133 showing that a detected range falls within a field of view detectable
by infrared sensor 128, in consideration of easily recognizing a place by a client
on which food 121 is placed. In addition, by marking case 127 with mark 133 in a smaller
range than the field of view detected by infrared sensor 128, the temperature can
be surely detected during storing food 121. Particularly, detection intensity of infrared
rays is strongest in a central part of a range detected by infrared sensor 128, and
is weaker toward an end of the detection range. Therefore, in order to increase the
detection accuracy, case 127 is preferably provided with mark 133, with the center
as a reference.
[0067] Regarding such a mark, when infrared sensor 128 is provided to the top panel side
of upper stage freezing room 103, being the storage room including a drawer type door
as described in this embodiment, it is difficult for the user to recognize the position
of the food, namely, on which position the food should be placed when the food is
put in a state that drawer type door 103a is opened. Therefore, the user can precisely
place the food by mark 133, thus making it possible to improve the detection accuracy
of infrared sensor 128.
[0068] Next, infrared sensor 128 used in this example will be described. Infrared sensor
128 detects infrared rays emitted from a range of a detected surface by a thermopile
(not shown) in a leading end thereof so as to convert into an electric signal. A probe
(not shown), being a converging member, for narrowing down a detection range of infrared
sensor 128 is provided around the thermopile, and the temperature is detected by calculating
the temperature of a detected object in comparison with a voltage of a thermistor
(not shown) set at a reference temperature disposed in a substrate portion. Within
a circle of the detection range by infrared sensor 128, infrared ray detection intensity
is strongest in the center, and is weaker toward the end portion. Therefore, the intensity
of the infrared rays of the detection object can be increased by narrowing down the
viewing angle of the thermopile, so that the temperature of an object can be surely
detected. However, the viewing angle is partially overlapped with the leading end
portion of the probe, and therefore the sensor is affected by the temperature of the
leading end portion, resulting in the erroneous detection. Therefore, according to
this embodiment, the viewing angle of the thermopile is set to 55° or less (for example
50° in FIG. 3).
[0069] In infrared sensor 128 used in this embodiment, the thermopile constituted of many
thermocouples formed on a silicon substrate is used. Further, a probe portion is a
molding in which alumina powder having excellent heat conductivity is used as a material.
However, a molding with ceramic powder such as magnesia powder or aluminum nitride
powder dispersed therein is also acceptable, provided that it is the material having
excellent heat conductivity. Further, with regard to a sensing responsiveness of infrared
sensor 128, when a resin type probe is used, the responsiveness is delayed. However,
a specific weight can be reduced, thus exhibiting effect in reducing weight. By thinning
a thickness of the resin type probe, a slight improvement in responsiveness is achieved,
and also volume can be reduced. This contributes to reducing environmental load by
saving materials. Regarding thinning in thickness, the same thing can be said for
a metal material having excellent heat conductivity.
[0070] Thus, in order to improve the detection accuracy of infrared sensor 128, the viewing
angle becomes narrower by having the probe, being the infrared ray converging member
for narrowing down a detected range. However, by having the probe, the detection accuracy
can be improved.
[0071] Further, the surface detected by infrared sensor 128 is formed of a material having
a cold storing function. Accordingly, temperature fluctuation of the detection surface
itself is reduced, and therefore when a warm food is put in, the temperature can be
further accurately detected.
[0072] Then, an operation and an action of the refrigerator constituted as described above
will be described.
[0073] For example, when the temperature of the inside of refrigerating room 102 is increased
by heat invasion from outside air or by opening and closing the door, and a refrigerating
room sensor (not shown) indicates the temperature more than a starting temperature
of compressor 117, compressor 117 is activated to start cooling operation inside of
refrigerating room 102. The refrigerant of high temperature and high pressure discharged
from compressor 117 is cooled and liquefied by heat exchange with air outside of outer
box 124 and urethane heat insulating material 126 inside of outer box 124, through
the heat radiating pipe (not shown) installed in a capacitor (not shown) or outer
box 124 in particular, in a process to finally reach a drier (not shown) disposed
in machine room 119.
[0074] Next, pressure of the liquefied refrigerant is reduced by capillary tube 118, which
is then flown into cooler 107 to perform heat exchange with interior air around cooler
107. The cold air that has undergone heat exchange is blown out to inside by cold
air ventilation fan 116 nearby, so that interior atmosphere is cooled. Thereafter,
the refrigerant is heated and gasified, and is returned to compressor 117. When the
interior atmosphere is cooled and the temperature of a freezing room sensor (not shown)
indicates a stop temperature or less, the drive of compressor 117 is stopped.
[0075] The refrigerator carries out cooling drive by repeating the above-described drive
cycle. At this time, when drawer type door 103a is closed, infrared sensor 128 detects
the temperature of case 127 or the temperature of food 121 positioned within the upper
stage freezing room, by thermopile 129 attached to the top panel of upper stage freezing
room 103.
[0076] However, when the door is opened for putting in food 121 or taking out materials
other than food 121, or for confirming stored food 121, detection of infrared sensor
128 is deviated from the surface of case 127 and the detection surface of target food
121, and the temperature of third thermally insulated partition portion 112 is detected,
which is a partition wall for partitioning between the storage room positioned on
the projected line in a detecting direction of infrared sensor 128, and the storage
room in which infrared sensor 128 is installed. As conventional in a case of the refrigerator
in which the adjacent storage rooms positioned on a projected surface of the surface
detected by infrared sensor 128, namely, on the projected line in the detecting direction
of infrared sensor 128, are set in a higher temperate zone than the frozen temperature
zone by 20°C or more, a temperature difference is caused by heat conduction on the
surface of third thermally insulated partition portion 112. Therefore, the temperature
detected by infrared sensor 128 is suddenly changed rather highly, thus inviting the
erroneous detection showing that warm food is put into the storage room.
[0077] However, according to this embodiment, temperature zones of the adjacent storage
rooms with third thermally insulated partition portion 112 held between them are set
as the same temperature zones or the adjacent storage room is set as a lower temperature
zone than the storage room. Therefore, consumption of useless energy such that variation
of the detected temperature becomes small and deviation in detection occurs, thus
requiring unnecessary cooling capacity, then increasing the number of rotations of
compressor 117 or increasing the number of rotations of cold air ventilation fan 116,
can be prevented.
[0078] Particularly, as with the embodiment, in a case that the non-contact sensor is installed
in a drawer type storage room, the non-contact sensor detects third thermally insulated
partition portion 112, being a wall surface on the side of the projected surface when
the door is opened, thus detecting the vicinity of the same temperature as the storage
room or a lower temperature than the temperature of the storage room. Therefore, the
adjacent storage rooms are not set to have higher temperatures during open/close of
the door, thus making it possible to suppress the erroneous detection by the non-contact
sensor such that the warm food is put in.
[0079] Further, conventionally by providing a door switch and causing interlocking motion
with the switch, open/close state of the door is grasped, and when the door switch
is started, infrared sensor 128 is set in an undetectable state. With this structure,
the erroneous detection is prevented. However, by providing the door switch and causing
interlocking motion with the switch, the structure is further complicated. Therefore,
there is a possibility that malfunction or failure in operation is increased, and
further, owing to addition of a control mechanism including the door switch and wiring,
etc, for causing interlocking motion with the switch, a cost rise is considered to
occur in a circumstance of escalating component prices due to global insufficient
raw materials, thereby causing a cost increase in an actual sales.
[0080] However, in this example, for example, when the door is closed and food 121 is stored
therein, the food of higher temperature than the temperature of the circumference
is detected, and in an open state of the door, the temperature such as a lower temperature
zone or the same temperature zone than/as the temperature of the storage room in which
the infrared sensor is installed, is detected. Therefore, for example even in a case
where the temperature is temporarily increased by opening the door, when the warm
food is not actually put in, sudden temperature drop can be detected thereafter, and
therefore by calculating a temperature gradient within a specific time period and
providing a threshold value, it is possible to determine start of automatic rapid
freezing only when the threshold value indicates a specific value or more. Thus, detection
whether the temperature rise is caused by external disturbance is possible, only by
setting a control specification with a simple structure without providing the door
switch. Accordingly, as described above, an effect is expected as follows. Specifically,
material resources can be saved and attachment error, etc, can be prevented during
assembly of the components, with further high reliability.
[0081] Further, in a humid weather condition specific to Japan, when the door is opened,
warm humidity of outside air is flown to inside the refrigerator. However, when the
dew condensation is formed on the surface of infrared sensor 128, thermopile 129 detects
the temperature of dew condensation water. Further when the door is closed and interior
cooling drive is started, the dew condensation water is frozen, thus making it difficult
to detect the temperature of the food by thermopile 129 until the frozen water droplet
is sublimated. Therefore, in this embodiment, infrared sensor 128 is installed at
the refrigerating room side to obtain an effect of preventing the dew condensation
by disposing it in the thermally insulated partition portion that partitions the reserve
room where the temperature is higher than the temperature of the adjacent storage
room, and also installed closer to the door where the temperature is highest in a
temperature distribution of the thermally insulated partition portion. A shutter mechanism
can also be mounted as the conventional example, for preventing the dew condensation.
However, in this case, interlocking motion with open/close of the door is required,
thus requiring a complicated mechanism.
[0082] Further, by installing infrared sensor 128 at a part of the storage room where average
temperature is higher than a surrounding temperature, a design, in which sticking
of moisture hardly occurs, being a cause of aging deterioration, can be achieved.
Therefore an effect of prolonging a product service life can be obtained.
[0083] Further, an object of this example is to detect the temperature of food 121 by infrared
sensor 128. In this case, simultaneously with detecting the temperature of food 121,
infrared sensor 128 detects the temperatures of all materials within a field of view
of infrared sensor 128, and therefore detects infrared rays emitted from a wall surface
of the storage room or food 121 stored in the storage room. Therefore, when the temperature
of a surface detected by infrared sensor 128 is increased by flow of warm air accompanied
by open/close of the door, detection accuracy of detecting the temperature of food
121 by infrared sensor 128 is deteriorated. Accordingly, the surface detected by infrared
sensor 128 has preferably a constant temperature and has a cold storing function in
this embodiment. Thus, when the detected surface has the cold storing function, further
constant temperature can be maintained within a detected range in an interior wall
surface, etc. Therefore, it is possible to prevent such a case that the erroneous
detection occurs, in which the food other than food 121 is put in, by flow of the
warm air, etc, being the temperature rise due to a so-called external disturbance,
and useless energy is consumed by excessively cooling the storage room by starting
automatic rapid cooling because of this erroneous detection.
[0084] Further, when such an automatic rapid cooling is started, a temperature fluctuation
by putting in the food cannot be discriminated from a temperature fluctuation by external
disturbance other than putting in the food. Therefore, there is a possibility of the
erroneous detection such that the temperature fluctuation by external disturbance
is caused by putting in the food. Therefore, in order to prevent the detection by
such an external disturbance, determination time is provided for determining whether
the food is put in, as external disturbance detecting means for surely detecting the
presence/absence of input food. Then when a warm temperature is detected, the putting
in of food is surely determined by monitoring the temperature fluctuation of a constant
determination time after detection of the warm temperature, and only when a high temperature
is always detected during the determination time, automatic rapid cooling is started,
so that the presence/absence of the input food is surely determined. Further, the
determination time can also be started after elapse of a constant time from detecting
the warm temperature, and particularly in a case of the temperature rise due to flow
of the warm air, the temperature rapidly drops. Therefore, the temperature is detected
again after elapse of a constant time, and only when a high temperature is detected,
the automatic rapid cooling is started, so that the presence/absence of the input
food is surely determined. Useless energy consumption by excessively cooling the storage
room by starting automatic rapid cooling by erroneous detection can be prevented by
providing the aforementioned external disturbance detecting means.
[0085] Further, when infrared sensor 128 is installed in the storage room, this example
gives consideration to installing infrared sensor 128 in the storage room, so that
a surface of a sensor probe is disposed under the surface of the thermally insulated
partition portion. With this structure, the temperature fluctuation during detection
is reduced by not excessively cooling the leading end portion of the probe by the
cold air from the cold air discharge portion the back face. In addition, with this
structure, lack or detachment of components under action of excessive force can be
suppressed, which is caused by catching the food or adhesion of foreign matters when
more than allowable amount of food is stored, or by catching of the leading end of
infrared sensor 128 by fingers or towel, etc, being a cleaning tool during cleaning.
[0086] Further, infrared sensor 128 erroneously detects when thermistor 131 detecting its
own temperature generates an excessive temperature fluctuation. Therefore, infrared
sensor 128 and thermistor 131 are set apart from each other, so that infrared sensor
128 is not exposed to temperature influence from a part where heat fluctuation occurs.
A pipe mainly composed of a metal material such as copper or iron is arranged in the
refrigerator, for releasing heat and preventing surface dew condensation. Therefore,
in this embodiment, a distance from the pipe is set to 15mm or more.
[0087] As a countermeasure against dew condensation and freezing of the leading end portion
of infrared sensor 128, there is a method of utilizing a heat of a heater. In this
case, when a method of fixing a chip resistance to a substrate is used, a cost can
be reduced. As a capacitance of the chip resistance, the temperature rise of the leading
end of the probe can be sufficiently secured, if energization rate is about 20 minutes
per day under voltage of 5 V toward a capacitance of about 0.25 W in a case of infrared
sensor 128 of this embodiment. Further, a method of periodically refreshing by securely
removing the dew condensation and the freezing by frequently as not every day but
once in a month in a refrigerator of long use is also effective for prolonging the
product service life.
[0088] As the refrigerant of a freezing cycle of recent years, isobutene, being a flammable
refrigerant with a small global warming coefficient is used from a viewpoint of global
environmental protection. Isobutane, being hydrogen carbide, has a specific gravity
of about twice at a normal temperature and under atmospheric pressure, compared with
air (under 2.04 and 300K). If the isobutene, being the flammable refrigerant, is leaked
from the freezing system when compressor 117 stops, the isobutene leaks downward,
because it is heavier than air. Particularly, when the isobutene is leaked from cooler
107 having much residual amount of the refrigerant, there is a possibility that a
leak amount is increased. However, upper stage freezing room 103 with infrared sensor
128 installed therein, is set on an upper side of cooler 107, and therefore even in
a case of the leak, the isobutene does not leak to upper stage freezing room 103.
Also, even if the isobutene leaks to upper stage freezing room 103, it remains in
a lower part of the storage room, because the refrigerant is heavier than air. Therefore,
since infrared sensor 128 is installed on the top panel of the storage room, there
is little possibility that the vicinity of infrared sensor 128 reaches a flammable
concentration.
(Embodiment 1)
[0089] In the present embodiment, a detailed description will be omitted with regard to
the same portion as the structure and the technical concept as described in Example
1. With regard to the structure to which the same technical concept as the content
described in Example 1 can be applied, it is possible to achieve a structure obtained
by combining with the technical content and the structure described in Example 1.
[0090] FIG. 1 previously described is also a front view of a refrigerator according to Embodiment
1 of the present invention. Further, FIG. 2 previously described is also a side section
view of the refrigerator according to Embodiment 1 of the present invention. FIG.
4 is a partially expanded side section view of an upper stage freezing room of the
refrigerator according to Embodiment 1 of the present invention.
[0091] As shown in FIGS. 1, 2 and 4, refrigerator main body 101 is a thermally insulated
box body constructed by outer box 124 which is open forward and is made of metal (such
as steel plate), inner box 125 which is made of a hard resin (such as ABS), and urethane
heat insulating material 126 which is foamed and filled between outer box 124 and
inner box 125, and is constructed by refrigerating room 102 provided at an upper part
of the main body, upper stage freezing room 103 provided below the refrigerating room,
ice making room 104 provided below refrigerating room 102 and in parallel with upper
stage freezing room 103, vegetable room 106 provided at a lower part of the main body,
and lower stage freezing room 105 provided between upper stage freezing room 103 and
ice making room 104 installed in parallel with each other, and vegetable room 106.
Front face portions of upper stage freezing room 103, ice making room 104, lower stage
freezing room 105 and vegetable room 106 are openably closed by drawer type doors
(not shown), and a front face of refrigerating room 102 is openably closed by a door
(not shown), for example, of a double-hinged door.
[0092] Refrigerating room 102 is set normally between 1°C and 5°C for storing under freeze
while setting an ice-free temperature to a lower limit. It is often the case that
vegetable room 106 is set between 2°C and 7°C which is a set temperature equal to
or slightly higher than refrigerating room 102. If it is set to a low temperature,
it is possible to maintain a freshness of a leaf vegetable for a long period. Upper
stage freezing room 103 and lower stage freezing room 105 are normally set between
-22 and -18°C for storing under freeze, however, in order to improve the frozen storage
state, it may be set to the low temperature, for example, between -30 and -25°C.
[0093] Since cold room 102 and vegetable room 106 are set their insides to plus temperatures,
they are called as a refrigeration temperature zone. Further, upper stage freezing
room 103, lower stage freezing room 105 and ice making room 104 are set their insides
to minus temperatures, and they are called as a frozen temperature zone.
[0094] A top surface portion of refrigerator main body 101 is provided with a stepped recess
toward a back face direction of refrigerator main body 101 so as to form machine room
119, and is constructed by a first top surface portion and a second top surface portion.
A cooling operation is carried out by sealing a refrigeration cycle obtained by sequentially
connecting compressor 117 arranged in the stepped concave portion, a dryer (not shown)
removing a water content, a condenser (not shown), a heat radiation pipe (not shown)
for radiating heat, capillary tube 118, and cooler 107. It is often the case that
a combustible cooling medium has been used in the cooling medium for an environmental
protection, in recent years. In this case, in the case of the refrigeration cycle
using a three way valve and a switch valve, these functional parts can be arranged
within the machine room.
[0095] Further, refrigerating room 102, ice making room 104 and upper stage freezing room
103 are defined by first thermally insulated partition portion 110.
[0096] Further, ice making room 104 and upper stage freezing room 103 are defined by second
thermally insulated partition portion 111.
[0097] Further, ice making room 104, upper stage freezing room 103 and lower stage freezing
room 105 are defined by third thermally insulated partition portion 112.
[0098] Since second thermally insulated partition portion 111 and third thermally insulated
partition portion 112 are parts which are assembled after foaming refrigerator main
body 101, a foamed polystyrene is used normally as the thermally insulated material,
however, a rigid urethane foam may be used for improving a heat insulating performance
and a rigidity, and a further thinness of a compartment structure may be achieved
by inserting a vacuum insulating material having a high heat insulating property.
[0099] Further, a cooling wind path can be secured and an improvement of a cooling capacity
can be achieved, by securing an operation portion of a door frame so as to thin or
abolish the shapes of second thermally insulated partition portion 111 and third thermally
insulated partition portion 112. Further, a reduction of a material is achieved by
hollowing out center portions of second thermally insulated partition portion 111
and third thermally insulated partition portion 112 so as to form a wind path.
[0100] Further, lower stage freezing room 105 and vegetable room 106 are defined by fourth
thermally insulated partition portion 113.
[0101] Cooling room 123 covered with cooling room cover 122 is provided in a back face of
refrigerator main body 101. Within cooling room 123, fin and tube type cold air creating
cooler 107 is arranged as a representative example in a back face of lower stage freezing
room 105 including a rearward region of second and third thermally insulated partition
portions 111 and 112 corresponding to thermally insulated room wall so as to be longer
than is wide in a vertical direction. Further, a material of cooler 107 employs aluminum
or a copper.
[0102] Cold air ventilation fan 116 ventilating the cold air created by cooler 107 to each
of storage rooms including refrigerating room 102, ice making room 104, upper stage
freezing room 103, lower stage freezing room 105 and vegetable room 106 based on a
forced convection method is arranged in the vicinity (for example, an upper space)
of cooler 107, and radiant heater 134 made of a glass tube and serving as a defrosting
device removing a frost attached to cooler 107 and cold air ventilation fan 116 at
a time of cooling is provided in a lower space of cooler 107. The defrosting device
is not particularly designated, but a pipe heater closely attached to cooler 107 may
be used in addition to radiant heater 134.
[0103] Within cooling room cover 122, there is provided a duct ventilating the cold air
from cold air ventilation fan 116 to each of the storage rooms, and it directly ventilate
the cold air in cooler 107 to upper stage freezing room 103 and lower stage freezing
room 105 through the duct.
[0104] Cold air ventilation fan 116 may be directly arranged in inner box 125, however,
it is possible to achieve a reduction of a manufacturing cost by arranging it in second
thermally insulated partition portion 111 which is assembled after being foamed, and
carrying out a block work of the parts.
[0105] Next, a description will be given of a structure of upper stage freezing room 103
to which infrared sensor 128 is attached.
[0106] As shown in FIG. 4, infrared sensor 128 corresponding to a non-contact sensor detecting
a temperature of food 121 is installed in first thermally insulated partition portion
110 corresponding to a ceiling surface of upper stage freezing room 103 toward a direction
(a downward direction in the present embodiment) in which an adjacent storage room
on a plane of projection of the food mounting portion corresponding to the detecting
surface exists. As mentioned above, infrared sensor 128 is provided in the storage
room wall surface close to the opposed side to the food mounting portion, and since
the food mounting portion is provided with cool storage medium 142 having a heat storage
function, the food mounting portion has a heat storage function. Further, a back face
upper portion of upper stage freezing room 103 is provided with first discharge port
132 discharging the cold air to an inside room from cooling room cover 122, and a
return port (not shown) for the cold air circulating within upper stage freezing room
103 again returning to cooling room 123. In this case, since it is possible to make
infrared sensor 128 hard to be affected by the wind of the cold air discharged from
first discharge port 132, by installing infrared sensor 128 within the thermally insulated
partition portion, it is possible to achieve an improvement of a detection precision.
Further, since any foreign material is not attached to a detection portion of infrared
sensor 128 in the case that a large amount of foods 121 are entered into the storage
room or even at a cleaning time, by setting a leading end portion of infrared sensor
128 inside the surface of the thermally insulated partition portion, an erroneous
motion of the detection is not caused. Further, since there is no catch at a time
of cleaning caused by a protrusion to the room inside, it is possible to prevent a
lacking of part and a displacement in a detecting direction due to an application
of an excessive force. Further, since no protrusion is provided within the room, a
room inside capacity is not reduced and there is an advantage that the capacity can
be secured.
[0107] In this case, if mark 137 indicating a field of view is provided in the food mounting
portion of case 127 within the storage room detected by infrared sensor 128, a storage
site of food 121 is easy to be known for a customer, and it is possible to securely
detect the temperature at a time of storing food 121, by additionally setting mark
137 in a smaller range than the field of view detected by infrared sensor 128. Particularly,
since infrared sensor 128 is structured such that a detection intensity of the infrared
ray becomes strongest in a center portion of the detecting range and becomes weaker
toward an end of the detection range, it is preferable to put mark 137 based on the
center for enhancing the detection precision. In the present embodiment, since the
food mounting portion is formed by cool storage medium 142, mark 137 is attached to
an upper surface side of cool storage medium 142.
[0108] Next, a description will be given of infrared sensor 128 which is used in the present
embodiment.
[0109] Infrared sensor 128 detects an amount of the infrared ray emitted from the range
of the detecting surface by a thermopile in a leading end thereof so as to convert
into an electric signal. A probe is provided in the periphery of the thermopile, and
a temperature detection is carried out by calculating a temperature of the detected
subject by comparing with an electric voltage of the thermistor (not shown) corresponding
to a reference temperature arranged in a substrate portion. Infrared sensor 128 is
structured such that an infrared ray detection intensity is strongest in a center
and the detection intensity becomes weaker toward an end, in a circle inner portion
of the detecting range. Accordingly, it is possible to increase the intensity of the
amount of infrared ray of the detected subject by narrowing a viewing angle of the
thermopile, and it is possible to securely detect the temperature of the subject.
However, since a part of the viewing angle laps over the leading end portion of the
probe, it is affected by a temperature of the leading end portion so as to cause an
erroneous detection. Therefore, according to the present embodiment, the viewing angle
of the thermopile is set to 50°. Accordingly, mark 137 mentioned above can improve
a precision of detection by mainly being attached to the center of the circle inner
portion of the range detected by the infrared sensor.
[0110] Infrared sensor 128 used in the present embodiment employs the thermopile constructed
by a lot of thermo couples formed on a silicon substrate. Further, a material of the
probe portion is a molded product using alumina powder which is excellent in a thermal
conductivity, however, any molded product obtained by dispersing a ceramic powder,
for example, a magnesia powder, aluminum nitride powder or the like may be employed
as far as the material which is excellent in the thermal conductivity. Further, if
a resin type probe is used in a detection response of infrared sensor 128, a delay
is generated in a response, however, since a specific gravity can be reduced, it is
effective for a weight saving. It is possible to achieve a slight improvement of the
response by reducing a thickness in the resin type probe. Since it is possible to
reduce a volume, it is possible to lower an environmental load by a material saving.
Thinning is same applied to the metal material which is excellent in the thermal conductivity.
[0111] With regard to the refrigerator constructed as mentioned above, a description will
be given below of a motion and an operation thereof.
[0112] In the case that the room inside temperature rises and a refrigerating room sensor
(not shown) becomes a start temperature or more of compressor 117, for example, due
to a heat intrusion from an ambient air or a door opening and closing in refrigerating
room 102, compressor 117 is started and the cooling in the room is started. A high-temperature
and high-pressure cooling medium discharged from compressor 117 is cooled and liquefied
based on a heat exchange with the air outside outer box 124 and urethane heat insulating
material 126 within the room, until finally reaching a dryer (not shown) arranged
in machine room 119, particularly in a condenser (not shown) or a heat radiation pipe
(not shown) installed in outer box 124.
[0113] Next, the liquefied cooling medium is depressurized by capillary tube 118, flows
into cooler 107 and is heat exchanged with the room inside air in the periphery of
cooler 107. The heat exchanged cold air is ventilated into the room by cold air ventilation
fan 116 in the vicinity thereof so as to cool the room inside. Thereafter, the cooling
medium is heated and gasified so as to be turned back to compressor 117. In the case
that the room inside is cooled and the temperature of the freezing room sensor (not
shown) becomes equal to or less than the stop temperature, the operation of compressor
117 is stopped.
[0114] Further, since the door is closed at this time, infrared sensor 128 detects the temperature
of case 127 within the upper stage freezing room from the thermopile attached to the
top surface of upper stage freezing room 103 or the temperature of food 121. The refrigerator
carries out a cooling operation by repeating the operation cycle mentioned above.
[0115] Next, a description will be given of a case that the load such as the food or the
like is put in.
[0116] For example, in the case food 121 is put in upper stage freezing room 103 so as to
be rapidly frozen, for example, in the case of buying a fresh food such as meat, fish
or the like in a supermarket or the like, and in the case of cooking food 121 such
as a hamburger or the like in the home so as to keep in a freezer, food 121 has been
rapidly frozen conventionally by manually turning on a rapid freezing control. However,
there is listed up a point of a bad usability that a work load of the user is increased
by carrying out such a motion as to turn on the rapid freezing control manually after
putting in food 121.
[0117] Further, there is a structure which can decide a time until the rapid freezing control
is finished based on a set temperature of food 121, however, since it is optionally
decided and a freezing speed is differentiated, for example, according to a magnitude
and a thickness of food 121, there is a possibility that food 121 is not frozen even
if the set temperature is detected, and it does not pass through the maximum frozen
crystal creating range. Further, in the case that the set temperature is low, such
a useless energy that the cooling operation is not finished and compressor 117 at
a time of rapidly freezing is driven at a high speed in spite that food 121 is frozen
may be used. Further, the temperature of food 121 is cooled under the influence of
the peripheral temperature during the temperature set of the rapid freezing control
end with respect to input food 121, and the thin food enters into the maximum frozen
crystal creating range around turning on the rapid freezing control. Accordingly,
there is a possibility that the suppression of the cell breakage is delayed and the
fresh keeping characteristic is adversely affected.
[0118] Further, the prior art includes a structure in which the freezing is completed and
the rapid freezing control is finished by detecting a change from a latent heat change
of food 121 to a sensible heat change, however, there is a case that rates of the
latent heat change and the sensible heat change are the same according to the magnitude
and the thickness of food 121, for example, in a change rate of the sensible heat
change. In the case that the magnitude of food 121 is large, the change rate in the
sensible heat change becomes small, and in the case that the thickness of food 121
is small, the change rate in the sensible heat change becomes large. In other words,
the change rate of the sensible heat change of food 121 is not constant, and in order
to determine the frozen end based on the change rate, it is unavoidable to employ
the change rate which is in conformity to the magnitude of larger food 121. Accordingly,
in the case that the magnitude of food 121 is small, the cooling operation is carried
out even if it is frozen, an additional cooling energy is used. Further, there is
a case that the change rates of the latent heat change and the sensible heat change
are not different even in the case that the operation state of cold air ventilation
fan 116 and the cooling load state of the refrigerator are different by opening and
closing a damper (not shown). For example, in the case of the prior art, a load amount
in the case of cooling refrigerating room 102 and vegetable room 106 is different
from a load amount in the case of cooling freezing room 108, ice making room 104 and
switch room 109. In the case of cooling the load amount of refrigerating room 102
side, the temperature change rate of food 121 put in switch room 109 becomes small,
and in the case of cooling the load amount in freezing room 108 side, the change rate
becomes reversely large. Further, since the change rate becomes further smaller in
the case of cooling both the rooms, it is necessary to extract an enormous amount
of data and employ a complicated control specification for deriving the change rate
in conformity to each of them, and this is not realistic.
[0119] Accordingly, the present invention is structured such as to detect an amount of the
infrared ray emitted from the load such as the food into case 127 within the upper
state freezing room detected by infrared sensor 128, turn on the rapid freezing control
automatically in the case that that temperature calculated from the amount of the
infrared ray is equal to or more than a fixed temperature (an upper limit set temperature:
T0), and finish the rapid freezing control in the case that the temperature detected
by infrared sensor 128 detected after setting the rapid freezing control is equal
to or less than a fixed temperature (a lower limit set temperature: T1).
[0120] As a motion of the rapid freezing control, when food 121 is put in and the detection
temperature of infrared sensor 128 detects T0 corresponding to a start temperature
or higher, the refrigerator increases the amount of the circulating cooling medium
by increasing the rotating speed of compressor 117, and descends the temperature of
cooler 107. Further, it increases the rotating speed of cold air ventilation fan 116,
whereby it rapidly cools food 121 by increasing the cooling amount circulating the
cold air created by cooler 107 within the room. Thereafter, if it comes to the lower
limit set temperature T1 corresponding to the finish temperature after confirming
the passage of the temperature 0°C to -5°C corresponding to the maximum frozen crystal
creating range during the continuous detection of the temperature of food 121, the
maximum frozen crystal creating range affecting the freshness for storing the food
is rapidly passed by automatically finishing the rapid freezing control and changing
to the normal cooling operation. Since the deterioration of the freshness keeping
characteristic is hardly affected even by normally cooling after passing through the
maximum frozen crystal creating range, the normal operation is carried out. In the
present embodiment, the start temperature of the rapid freezing control, that is,
the upper limit temperature T0 is set to -2.5°C, and the end temperature of the rapid
freezing control, that is, the lower limit temperature T1 is set to -15°C. This is
because the state is differentiated by the food storage aspect or the food own aspect.
[0121] In accordance with the present embodiment, since the rapid freezing control is turned
on automatically and an improvement of the cooling capacity is automatically achieved,
it is possible to cool the refrigerator according to a cooling operation as occasion
demands. Particularly, since it is possible to shorten an operating time as an amount
of an electric power consumption of an actual refrigerator by employing a high-capacity
and short-time cooling, rather than by operating compressor 117 at a middle rotation
so as to slowly cool the load such as the conventional one, with respect to a rise
of the room inside temperature based on the load input or a cooling of the load to
be rapidly frozen, energy saving can be achieved. In the present embodiment, the cold
air in first and second discharge ports 132 and 133 is lowered near to -40°C so as
to rapidly freeze, by temporarily setting the rotating speed of compressor 117 to
80 Hz during the rapid freezing control, and setting the rotating speed of cold air
ventilation fan 116 to about 3000 rotation per minute, however, a time is shortened
for 30 minutes or more with respect to the conventional rapid freezing control, and
an energy saving effect Δ23 % can be obtained per one time as an energy saving effect.
[0122] Further, in the present embodiment, since cool storage medium 142 is attached within
the case of upper stage freezing room 103, a freezing effect caused by a direct thermal
transmission from frozen cool storage medium 142, that is, a thermal conduction is
applied, in addition to a freezing effect caused by the thermal transmission by the
cold air at about -40°C created by cooler 107, a time passing through the maximum
frozen crystal creating range is further quickened and a drip amount from food 121
at a time of defrosting the food is reduced. Accordingly, it is possible to further
achieve an improvement of the food storage.
[0123] Particularly, since food 321 is cooled based on the cooling from cool storage medium
142, and case 127 is kept at a lower temperature than the case that cool storage medium
142 is not provided, it is possible to cool food 121 for a short time. Accordingly,
it is possible to achieve a reduction of the cooling operation time of the refrigerator
so as to achieve energy saving and it is possible to achieve an improvement of a freshness
keeping characteristic of food 321.
[0124] Further, since cool storage medium 142 is arranged, cool storage medium 142 absorbs
a thermal load of an ambient air inflow even in the case that food 121 is not put
in or even in the case that the ambient air inflows at a time of opening and closing
the door, it is possible to suppress the temperature rise within the room.
[0125] In other words, the effect of the present embodiment is as follows in the light of
the energy saving and the food storage.
[0126] First of all, in the light of the energy saving, since the temperature of the food
is detected by the sensor detecting in a non-contact manner so as to automatically
start the rapid freezing control, and the operation gives way to the normal cooling
motion rapidly at a time point when the temperature reaches the end temperature, the
rapid cooling of the food put in the room is rapidly and automatically started. Further,
since the food mounting portion has the heat storage function, the food mounting portion
which has been cooled to the frozen temperature zone and has the heat storage function
comes into contact with the food, whereby it is possible to directly absorb the heat
based on the thermal conduction and rapidly cool, it is possible to widely shorten
a continuous operating time of the compressor and the cold air ventilation fan even
in the case that the rapid freezing control is carried out, and it is possible to
carry out the rapid cooling in which the energy saving is further achieved.
[0127] Further, in the light of the food storage, in the present invention, since the food
mounting portion at a time of carrying out the rapid freezing control has the heat
storage function, whereby it is possible to rapidly cool by using both the thermal
transmission caused by introducing the cold air carrying out the rapid freezing control,
and the thermal conduction from the food mounting portion having the heat storage
function, the passing time of the maximum frozen crystal creating range of 0°C to
-5°C particularly affecting greatly the freshness in the frozen storage can be shortened.
Since it is possible to suppress the drip amount from the food at a time of defrosting
by passing through the maximum frozen crystal creating range for a short time, it
is possible to store without deteriorating the freshness and a taste of the food.
Accordingly, it is possible to enhance a storage quality of the food.
[0128] As mentioned above, in the present embodiment, since the rapid freezing control is
turned on automatically, and the rapid freezing control is automatically cancelled
at a time when the food is frozen, such a troublesome motion as to be manually applied
to food 121 to be rapidly frozen such as the conventional one is not necessary, and
it is possible to do away with a waste of an unnecessary energy caused by the unnecessary
cooling operation after freezing, and it is possible to achieve a further energy saving
since the food mounting portion is formed by cool storage medium 142.
[0129] Further, when the user comes back home from shopping and stores food 121 in the refrigerator
for keeping a fresh food such as meat or the like in a freezer, the room inside temperature
rises under the influence of the door open for a long time. In this case, since the
rapid freezing control is not turned on automatically in conventional, food 121 is
cooled for a long time by a low cooling capacity, however, in the present invention,
since the rapid freezing control is turned on automatically if the temperature is
high, based on the temperature detected by infrared sensor 128, it is possible to
rapidly cool without too long time by a high cooling capacity. As a result, since
it is possible to shorten the cooling time for cooling and it is possible to suppress
the temperature rise of the food itself based on the cooling for a short time, it
is possible to suppress the deterioration of the freshness keeping performance.
[0130] Further, since the cooling capacity is increased by raising the rotating speed or
the electric voltage of cold air ventilation fan 116 for operating compressor 117
at a high rotation and increasing a wind amount feeding the cold air created by cooler
107 into the room during the rapid freezing control, a noise level has risen conventionally
for a fixed time, however, in the present embodiment, since the rapid freezing control
is carried out around 0°C to -5°C corresponding to the maximum frozen crystal creating
range, it is possible to shorten the time 30 minutes or more with respect to the conventional
rapid freezing control time.
[0131] In this case, in the present embodiment, the upper limit and lower limit temperatures
are set as set temperatures of the rapid freezing control, however, it is possible
to classify the food input and only the door open and close by setting an auxiliary
detection period of a fixed time (for example, three minutes) after passing through
the set temperatures, and detecting a temperature behavior after putting in food 121.
Particularly, parts such as a part detecting the door open and close, for example,
a door switch, a harness and the like become expensive due to a worldwide material
cost rising and a mineral lack in recent years, and there is fear that the control
is complicated by adding the door switch. Accordingly, since it is not necessary to
use the door switch mechanism by setting the auxiliary detecting period, a resource
saving is achieved.
[0132] In this case, it is possible to clarify a simplicity caused by the automatic rapid
freezing control, by turning on a lamp or the like indicating the rapid freezing control
for showing to the user, for example, in the door portion of the front face, under
the rapid freezing control.
[0133] In this case, the rotating speed of compressor 117 is temporarily increased around
the temperature detecting period of the maximum frozen crystal creating range, under
the rapid freezing control, however, it is possible to protect the pressure in the
low pressure side of compressor 117 by deciding the upper limit of the rotating speed
of compressor 117 by the ambient air temperature. In the present embodiment, the rotating
speed is made lower than 80 Hz corresponding to the rotating speed of conventional
compressor 117 in the case of a middle ambient air temperature and a low ambient air
temperature, for example, the maximum rotating speed of compressor 117 is set to 69
Hz in the case that the ambient air temperature is 15°C.
[0134] Further, as the cooling medium of the refrigeration cycle in recent years, there
is used an isobutene corresponding to the combustible cooling medium having a small
global warming factor in the light of global environment maintenance. The isobutene
corresponding to a carbon hydride has a specific gravity (2.04 under 300 K) which
is about twice under a room temperature and an atmospheric pressure in comparison
with the air. If the isobutene corresponding to the combustible cooling medium leaks
from the refrigeration system at a time when compressor 117 stops, it is heavier than
the air, and leaks downward. Particularly, in the case of leaking from cooler 107
in which a holdup volume of the cooling medium is great, there is a possibility that
an amount of leakage is increased. However, since upper stage freezing room 103 arranging
infrared sensor 128 is installed above cooler 107, it does not leak into upper stage
freezing room 103 even if it leaks. Further, even if it leaks into upper stage freezing
room 103, the cooling medium is heavier than the air, and stays in a lower portion
of the storage room. Accordingly, since infrared sensor 128 is installed to the top
surface of the storage room, a possibility that a portion in the vicinity of infrared
sensor 128 comes to a combustible concentration is extremely low.
[0135] Further, in order to more precisely detect the temperature of food 121, it is possible
to improve a precision by detecting an area of food 121 after the food is put in,
and adjusting a detection viewing angle of infrared sensor 128 in correspondence to
the area of food 121. If it is possible to adjust the viewing angle by setting a position
having a different temperature from the periphery to a subject to be detected, particularly,
after putting in food 121, it is possible to improve a detection precision having
a high cost performance in comparison with the detection of the area of the food.
(Embodiment 2)
[0136] In the present embodiment, a detailed description will be omitted with regard to
the same portions as the structure and the technical concept described in Embodiment
1. With regard to the structure to which the same technical concept as the content
described in Embodiment 1 can be applied, it is possible to achieve a structure obtained
by combining with the technical content and the structure described in Embodiment
1.
[0137] FIG. 5 is a partially expanded side section view of a refrigerator according to Embodiment
2 of the present invention. In FIG. 5, it is possible to cool the food mounting portion,
that is, cool storage medium 242 from both upper and lower sides, by doing away with
the surface detected by infrared sensor 228, that is, third thermally insulated partition
portion 212 of the food mounting portion. Accordingly, since it is possible to cool
food 221 put in upper stage freezing room 203 from the lower state by the cold air
cooling lower stage freezing room 205, it is possible to extremely improve the cooling
speed in addition to the case that third thermally insulated partition portion 212
is provided. Since it has been known that food 221 is less broken its cell breakage
if it passes through a maximum frozen crystal creating range at 0°C to -5°C for a
short time at a time of freezing, cooling food 221 from the upper and lower sides
by doing away with third thermally insulated partition portion 212 is very effective
for storing the food.
[0138] Further, in the present embodiment, since cool storage medium 242 is attached within
the case of upper stage freezing room 203, a freezing effect caused by the direct
thermal conduction from frozen cool storage medium 242, that is, the thermal conduction
is applied, in addition to the refrigerating effect caused by the thermal transmission
by the cold air at about -40°C created by cooler 207. Accordingly, a time passing
through the maximum frozen crystal creating range is further quickened and a drip
amount from food 221 at a time of defrosting the food is reduced. Therefore, it is
possible to further achieve an improvement of the food storage.
[0139] Particularly, since food 221 is cooled based on the cooling from cool storage medium
242, and container 227 corresponding to the case is kept at a lower temperature than
the case that cool storage medium 242 is not provided, it is possible to cool food
221 for a short time. Accordingly, it is possible to achieve a reduction of the cooling
operation time of the refrigerator so as to achieve energy saving and it is possible
to achieve an improvement of a freshness keeping characteristic of food 221.
[0140] Further, since cool storage medium 242 is arranged, cool storage medium 242 absorbs
a thermal load of an ambient air inflow even in the case that food 221 is not put
in or even in the case that the ambient air inflows at a time of opening and closing
the door, it is possible to suppress the temperature rise within the room.
(Embodiment 3)
[0141] In the present embodiment, a detailed description will be omitted with regard to
the same portions as the structure and the technical concept described in Embodiments
1 to 2. With regard to the structure to which the same technical concept as the content
described in Embodiments 1 to 2 can be applied, it is possible to achieve a structure
obtained by combining with the technical content and the structure described in Embodiments
1 to 2.
[0142] FIG. 6 is a side section view of a refrigerator according to Embodiment 3 of the
present invention. In FIG. 6, the structure is made such as to cool a frozen temperature
zone including upper stage freezing room 403 and lower stage freezing room 405, and
a cold temperature zone including refrigerating room 402 and vegetable room 406 respectively
by freezing cooler 414 and refrigerating cooler 415 having different evaporating temperatures.
Accordingly, since food 421 put in case 427 in which cool storage medium 426 is stored
in a bottom surface in upper stage freezing room 403 provided with infrared sensor
425 in a top surface can reduce a cooling load amount with respect to a refrigeration
capacity of freezing cooler 414 in the refrigeration temperature zone, it is possible
to lower the temperature generated in freezing cooler 414, and it is possible to lower
a temperature of a discharger cold air from first and second discharge ports 432 and
433. Therefore, it is possible to raise a capacity for freezing food 421. Accordingly,
since it is possible to shorten a freezing time of food 421, it is possible to achieve
a reduction of an amount of electric power consumption.
INDUSTRIAL APPLICABILITY
[0143] As mentioned above, since the rapid freezing control is turned on automatically by
detecting the temperature of the food put in the storage room in which the infrared
sensor is installed, the improvement of the cooling capacity is automatically carried
out around the time zone of the maximum frozen crystal creating range, and the rapid
freezing control is automatically canceled, the cooling operation can be carried out
in correspondence to the load amount of the refrigerator. Accordingly, it is possible
to cool with ecology and at a high efficiency, and it is possible to apply to a general
refrigeration equipment detecting the temperature of the food.