BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to an air conditioner in which leakage of refrigerant
can be easily recognized by stimulating at least one of the senses of human such as
the sense of smell, the sense of sight, the sense of hearing or the like.
2. Description of the Related Art
[0002] Recently, HCFC-based refrigerant such as R22 having a small ozone-layer destruction
coefficient or the like has been used as refrigerant for a refrigerating machine,
however, alternative refrigerant containing no chlorine as constituent elements has
been required to be used from the viewpoint of complete prevention of the destruction
of the ozone-layer. HFC-based mixed refrigerant such as R407C, R410A or the like is
popular as the alternative refrigerant, however, even use of these materials cannot
suppress the global warming of the earth. Therefore, Research and development of HC-based
refrigerant group containing R290, etc. which have a global warming coefficient of
zero, air conditioners using these refrigerant group, etc. have been increasingly
promoted.
[0003] It is known that HC-based refrigerant group containing R290 which is propane gas
are generally flammable, and these materials has a problem in prevention of disasters
when the refrigerant leaks. Further, when a lot of refrigerant leaks into an enclosed
room, the oxygen concentration in the room is quickly reduced, and there is a risk
that inhabitants may be kept in an oxygen-deficient atmosphere. Therefore, in an air
conditioner as disclosed in Japanese Post-examined Utility Mode Registration Application
No. sho-60-38858, leakage of refrigerant is judged by a refrigerant leakage sensor
to produce an alarm sound from an alarm unit. However, in this type of air conditioner,
the recognition of the leakage of refrigerant is enabled only by stimulating the acoustic
sense of human, and thus when an inhabitant has an acoustic disorder or when the refrigerant
leakage sensor or the alarm is out of order, the above trouble cannot be avoided,
and finally a critical disaster may occur.
SUMMARY OF THE INVENTION
[0004] Therefore, an object of the present invention is to provide an air conditioner which
can easily check leakage of refrigerant and enhance the safety when the refrigerant
leaks.
[0005] In order to attain the above object, according to a first aspect of the present invention,
an air conditioner (1) having a compressor (21), a condenser (23, 11), pressure-reducing
means (an expansion device) (15) and an evaporator (11, 23) which are successively
connected to one another in this order to construct a refrigeration cycle, is characterized
in that a prescribed smell element is added to refrigerant which is filled in the
refrigeration cycle.
[0006] According to the first aspect of the present invention, when the refrigerant leaks
from an indoor heat exchanger (11), a pipe connection portion or the like, the prescribed
smell element floats in the room, and inhabitants can easily recognize the leakage
of the refrigerant by stimulation of the sense of smell.
[0007] In the air conditioner of the first aspect, the prescribed smell element may provide
irritant smell to the refrigerant.
[0008] According to the above air conditioner, when the refrigerant leaks from the indoor
heat exchanger (11), the pipe connection portion or the like, the irritant smell floats
in the room, and inhabitants can easily and quickly recognize the leakage of the refrigerant
by the irritant smell.
[0009] In the air conditioner of the first aspect, the prescribed smell element is inactive
to the refrigerant, and it does not corrode the constituent elements of the refrigeration
cycle.
[0010] According to the above air conditioner, even when the prescribed smell element is
added, the physical properties of the refrigerant are not varied, and also no corrosion
occurs in the heat exchangers (11, 23) and a pipe group and also no expansion occurs
in a rubber group.
[0011] According to a second aspect of the present invention, an air conditioner having
a compressor (21), a condenser (23, 11), pressure-reducing means (expansion mean)
(15) and an evaporator (11, 23) which are successively connected to one another in
this order to construct a refrigeration cycle, is characterized in that prescribed
dye is added to at least one of refrigerant and refrigeration machine oil which are
filled in the refrigeration cycle.
[0012] According to the air conditioner of the second aspect, when refrigerant leaks from
an indoor heat exchanger, a pipe connection portion or the like, colored gas or colored
refrigeration machine oil (lubricant oil for a compressor, etc.) is jetted from the
leak portion, and thus inhabitants can easily recognize the leakage of the refrigerant.
[0013] In the air conditioner of the second aspect, the dye provides at least one of the
refrigerant and the refrigeration machine oil with bright color.
[0014] According to the above air conditioner, when the refrigerant leaks from the indoor
heat exchanger, the pipe connection portion or the like, the bright-color refrigerant
gas or the bright-color refrigeration machine oil is jetted from the leak portion.
Therefore, the inhabitants can easily and quickly recognize not only the leakage of
the refrigerant, but also the refrigerant leak position.
[0015] In the air conditioner of the second aspect, the dye is inactive to the refrigerant,
and does not corrode the constituent elements of the refrigeration cycle.
[0016] According to the above air conditioner, even when the dye is added, the physical
properties of the refrigerant is not varied, and no corrosion occurs in the heat exchangers
and a pipe group, and no expansion occurs in a rubber group.
[0017] According to a third aspect of the present invention, an air conditioner (1) having
a compressor (21), a condenser (23, 11), pressure-reducing means (expansion mean)
(15) and an evaporator (11, 23) which are successively connected to one another in
this order to construct a refrigeration cycle, flammable refrigerant being filled
in the refrigeration cycle, is characterized by including leakage detection means
(57) for detecting leakage of refrigerant from the refrigeration cycle, and means
(51) for stopping the operation of the compressor when the leakage of the refrigerant
is detected by the leakage detection means (57).
[0018] According to the air conditioner of the third aspect, when the leakage of the refrigerant
is judged on the basis of an output signal of leakage detection means such as a refrigerant
leakage sensor (57) or the like, a controller (51) stops the compressor (21) on the
basis of the output signal, whereby the pressure in the refrigeration circuit is lowered
to suppress the leakage of the refrigerant.
[0019] In the air conditioner of the third aspect, plural cut-off valves (61, 63) are provided
in the refrigeration cycle, and when the leakage of the refrigerant is detected by
the leakage detection means (57), the cut-off valves (61, 63) are closed to separate
the leakage position of the refrigerant from the refrigeration cycle.
[0020] According to the above air conditioner, when the leakage of the refrigerant is detected
on the basis of the output signal of the leakage detection means such as the refrigerant
leakage sensor (57) or the like, the controller (51) controls the cut-off valves (61,
63) disposed in refrigerant pipes at the inlet and outlet sides of the indoor heat
exchanger (11) on the basis of the output signal.
[0021] The air conditioner of the third aspect of the present invention further includes
a partition plate (5) for partitioning into an indoor space and an outdoor space a
single case in which the constituent elements of the refrigeration cycle are accommodated,
an air flow port (65) which is provided to the partition plate (5) and allows air
to flow therethrough between the indoor space and the outdoor space, a damper (67)
for closing and opening the air flow port (65), and means for opening the damper to
validate the air flow port (65) when the refrigerant leakage is detected by the leakage
detection mean.
[0022] According to the above air conditioner, when the refrigerant leakage is judged on
the basis of the output signal of the leakage detection means such as the refrigerant
leakage sensor or the like, the controller drives the damper on the basis of the output
signal so that the damper is open, and allows the indoor space and the outdoor space
to intercommunicate with each other, whereby the refrigerant leaking from the indoor
to the outdoor is discharged and air is newly introduced from the outdoor into the
indoor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023]
Fig. 1 is a diagram showing a refrigerant circuit and a control system of an air conditioner
according to the present invention
Fig. 2 is a perspective view showing the internal construction of the air conditioner
according to the present invention; and
Fig. 3 is a longitudinally-sectional view showing the internal construction of the
air conditioner according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Preferred embodiments according to the present invention will be described hereunder
with reference to the accompanying drawings.
[0025] Fig. 1 is a diagram showing a refrigerant circuit and a control system of an air
conditioner according to the present invention. In Fig. 1, a solid line represents
a refrigerant circuit (refrigeration cycle), and a one-dotted chain line represents
flow of a control signal. Figs. 2 and 3 are perspective and longitudinally-sectional
view showing the internal construction of the air conditioner. The air conditioner
of this embodiment is a so-called integral-type air conditioner including an indoor
unit and an outdoor unit which are fabricated into a single body, and HC-based flammable
refrigerant (R290) is used as refrigerant circulating in the refrigerant circuit.
[0026] The air conditioner 1 is disposed in a building in such a manner that it penetrates
through the wall 3 of the building, and the inside of the air conditioner 1 is partitioned
into an indoor portion (space) 7 and an outdoor portion (space) 9. In the indoor portion
7 are disposed an indoor heat exchanger 11, an indoor fan 13, a capillary tube 15
serving as an expansion device, etc. Further, in the outdoor portion 9 are disposed
a compressor 21, an outdoor heat exchanger 23, an outdoor fan 25, an accumulator 27,
a strainer 29, etc. In Fig. 1, reference numeral 31 represents a center impeller type
fan motor which is disposed in the outdoor portion 9, and it serves to drive an indoor
fan 13 and the outdoor fan 25 coaxially. The respective elements constituting the
refrigerant circuit are connected to one another through refrigerant pipes 33 to 40
which are used for flow of gas refrigerant or liquid refrigerant.
[0027] In the indoor portion 7 is also disposed an electronic control unit (hereinafter
referred to as "ECU") which comprises a CPU, input/output interfaces, ROM, RAM, etc.
The input interface of the ECU 51 is connected to a room temperature sensor 53 for
detecting the room temperature, an outside air temperature sensor 55 for detecting
the outside air temperature, a refrigerant leakage sensor 57 (leakage detection means)
for detecting (judging) the leakage of refrigerant on the basis of variation in concentration
of oxygen of the indoor portion 7, etc., and the output interface is connected to
the compressor 21, the fan motor 31, etc.
[0028] In this embodiment, electromagnetic cutoff valves 61 and 63 which are used to cut
off the refrigerant circuit and actuated on the basis of a control signal from the
ECU 51 are provided at the upstream side of the capillary tube 15 and the downstream
side of the indoor heat exchanger 11, respectively. The partition plate 5 is provided
with an intercommunication port 65 which makes an intercommunication between the indoor
portion 7 and the outdoor portion 9 and allows air to flow from the indoor portion
7 to the outdoor portion 9, and also provided with a damper 67 for opening/closing
the intercommunication port 65 and an electromagnetic actuator 69 for driving the
damper. Further, an alarm buzzer 71 is disposed in the indoor portion 7 and makes
an alarm sound when refrigerant leakage occurs. The electromagnetic actuator 69 and
the alarm buzzer 71 are connected to the output interface of the ECU 51, and they
are actuated on the basis of the control signal from the ECU 51 as in the case of
the electromagnetic cutoff valves 61 and 63.
[0029] HC-based refrigerant and refrigeration machine oil are hermetically filled into the
refrigeration cycle, and circulated in the compressor 21 and the heat exchangers 11
and 23 while mixed with each other. The HC-based refrigerant which is used for the
refrigeration cycle is inherently colorless and transparent and non-odorous. However,
in this embodiment, a prescribed smell element and dye are added. Further, the refrigeration
machine oil which is used together with the HC-based refrigerant is light color and
transparent, however, prescribed dye is added to the refrigeration machine oil in
this embodiment. The smell element provides irritant smell to the refrigerant, and
when the refrigerant is discharged to the air, it stimulates the sense of smell of
the human even when the amount thereof is slight. Further, the dye provides bright
color such as bright red color, bright yellow color or the like, and when the refrigerant
or the refrigeration machine oil is discharged to the air, the portion surrounding
the leakage portion is brightly dyed. It Is needless to say that the smell element
and the dye used in this embodiment are harmless to the human body and inactive to
the refrigerant and does not corrode the constituent parts of the refrigeration cycle,
and mercaptan and pigment may be used, for example. In the present invention, it is
sufficient that the leakage position is specified when the refrigerant leaks, and
thus the dye may be added to only one of the refrigerant and the refrigeration machine
oil.
[0030] Next, the flow of the refrigerant under cooling operation will be described.
[0031] Gas refrigerant which is sucked from the accumulator 27 through the refrigerant pipe
40 into the compressor 21 is adiabatically compressed and discharged as high-temperature
and high-pressure gas refrigerant from the compressor 21. The high-pressure gas refrigerant
thus discharged flows through the refrigerant pipe 33 into the outdoor heat exchanger
23. The high-temperature and high-pressure gas refrigerant is cooled by the outside
air and condensed into liquid refrigerant while passing through the outdoor heat exchanger
23, and thereafter flows through the refrigerant pipe 34, the strainer 29, the refrigerant
pipe 35, the electromagnetic cutoff valve 61 and the refrigerant pipe 36 into the
capillary tube 15.
[0032] The liquid refrigerant is reduced in pressure by the capillary tube 15, and then
flows through the refrigerant pipe 37 into the indoor heat exchanger 11. The liquid
refrigerant is vaporized into gas refrigerant while passing the indoor heat exchanger
11, and the indoor air which is sucked into the room by the indoor fan 13 is cooled
through the heat exchange between the indoor air and the liquid refrigerant with the
vaporization latent heat of the liquid refrigerant. The gas refrigerant which is vaporized
in the indoor heat exchanger 11 flows through the refrigerant pipe 38, the electromagnetic
cutoff valve 63 and the refrigerant pipe 39 into the accumulator 27, and then sucked
from the refrigerant pipe 40 into the compressor 21 again.
[0033] According to this embodiment, when refrigerant leakage occurs in the indoor portion
7 due to some cause, the refrigerant leakage is judged on the basis of the reduction
of the oxygen concentration by the refrigerant leak sensor 57, and the ECU 51 performs
the processing such as the leakage control, etc. That is, when a detection signal
representing the refrigerant leakage is input from the refrigerant leakage sensor
57, the ECU 51 stops the compressor 17 and the fan motor 31, and at the same time
it controls the electromagnetic cutoff valves 61 and 63 to cut off the refrigerant
circuit. Further, the ECU 51 controls the electromagnetic actuator 69 to drive the
damper 67 so that the damper 67 is opened.
[0034] Upon the stop of the compressor 17, the refrigerant flow in the refrigerant circuit
is stopped and the refrigerant pressure is lowered, so that the leakage rate of the
refrigerant is rapidly lowered. In addition, since the refrigerant circuit is cut
off, the refrigerant in the compressor 17 or the outdoor heat exchanger 23 can be
prevented from leaking even when refrigerant leakage occurs in the indoor heat exchanger
11, the capillary tube 15 or the pipe connection portion thereof. That is, the refrigerant
leakage portion in the refrigeration cycle can be separated from the other portions
in the refrigeration cycle to prevent the refrigerant leakage from expanding to the
other portions. Further, the leaking refrigerant is discharged through the intercommunication
port 65 to the outside by opening the damper 67, and at the same time fresh air is
introduced from the outside air. In addition, since the fan motor 31, etc. are stopped,
any spark which causes firing does not occur to thereby prevent burning of the refrigerant.
[0035] In parallel to the execution of the above processing, the ECU 51 controls the alarm
buzzer 71 to make an alarm sound, thereby acoustically making the inhabitants recognize
the refrigerant leakage. At the same time, the inhabitants can also easily recognize
the refrigerant leakage with the sense of smell and/or the sense of vision. That is,
even when the amount of the smell element is small, the irritant smell of the smell
element added to the refrigerant floats in the room, and the portion surrounding the
leakage portion is dyed with red or yellow color by the dye added to the refrigerant
even when the leakage amount of the refrigerant is small. Accordingly, even when an
inhabitant has troubles of any two of the sense o hearing, the sense of smell and
the sense of vision, he/she can recognize the refrigerant leakage, and open the door
or window or escape from the room.
[0036] As described above, according to the air conditioner of this embodiment, when the
refrigerant leakage occurs, the leakage amount can be suppressed to an extremely small
value, ventilation can be promoted and the firing can be prevented. Further, the inhabitants
can be made to recognize the refrigerant leakage with the sense of heating, the sense
of smell and the sense of vision. Therefore, high safety can be kept although flammable
refrigerant is used.
[0037] The present invention is not limited to the above embodiment, and various modifications
may be made. For example, in the above embodiment, the present invention is applied
to an in-wall type air conditioner. However, the present invention may be applied
to a separation type air conditioner in which an indoor unit and an outdoor unit are
separated from each other, or a heat pump type air conditioner. Further, the fan motor
may be designed in an explosion-proof type. In this case, when the damper of the intercommunication
port is opened at the refrigerant leakage time, the indoor fan and the outdoor fan
are driven to positively discharge the refrigerant to the outside and take in the
outside air. Further, the materials of the smell element and the dye to be added to
the refrigerant may be suitably selected in consideration of compatibility with the
refrigerant, easiness of removal when attached to furniture, the cost, etc.
[0038] According to the present invention, a prescribed smell element is added to the refrigerant
used in the air conditioner. Therefore, the prescribed smell element floats in the
room when the refrigerant leaks from the indoor heat exchanger, the pipe connection
portion or the like, whereby an inhabitant can easily recognize the refrigerant leakage.
[0039] Further, according to the present invention, a prescribed dye is added to at least
one of the refrigerant and the refrigeration machine oil used in the air conditioner.
Therefore, when the refrigerant leaks from the indoor heat exchanger, the pipe connection
portion or the like, the colored gas or the colored refrigeration machine oil is ejected
from the leakage portion. Accordingly, an inhabitant can easily recognize the refrigerant
leakage, and also can easily grasp the leakage position.
[0040] According to the present invention, the smell element or the dye added to the refrigerant
or the like is inactive to the refrigerant, and does not corrode the constituent elements
of the refrigeration cycle. Therefore, the physical properties of the refrigerant
are not changed by the addition of the smell element or the dye, and there occurs
no corrosion in the heat exchangers and the pipe group and no expansion in the rubber
group.
[0041] According to the present invention, in the air conditioner having the flammable refrigerant
filled in the refrigeration cycle, when the refrigerant leaks from the refrigeration
cycle, the driving of the compressor is stopped. Specifically, when the refrigerant
leakage is judged on the basis of the output signal from the refrigeration leakage
sensor or the like, the controller stops the compressor on the basis of the output
signal, whereby the pressure in the refrigeration cycle is lowered and the refrigerant
leakage is suppressed to thereby ensure high safety.
[0042] Further, according to the present invention, plural cutoff valves are provided in
the refrigeration cycle, and when the refrigerant leaks from the refrigeration cycle,
these cutoff valves are closed to separate the leakage position from the refrigeration
cycle. Accordingly, when the refrigerant leakage is judged on the basis of the output
signal of the refrigerant leakage sensor or the like, the controller drives the cutoff
valves disposed at the inlet and outlet sides of the outdoor heat exchanger to be
closed on the basis of the output signal, thereby preventing the refrigerant at the
other portions of the refrigeration cycle from leaking into the room, and keeping
high safety.
[0043] Still further, according to the present invention, the constituent elements of the
refrigeration cycle is accommodated in a single case, the intercommunication port
is formed in the partition plate through which the inside of the single case is partitioned
into the indoor side and the outdoor side, the damper for opening/closing the intercommunication
port is provided, and the damper is opened when the refrigerant in the refrigeration
cycle leaks. Accordingly, when the refrigerant leakage is judged on the basis of the
output signal of the refrigerant leakage sensor or the like, the controller drives
the damper on the basis of the output signal so that the damper is opened. Therefore,
the indoor and the outdoor intercommunicate with each other, so that the refrigerant
is discharged from the indoor to the outdoor and the air is introduced from the outdoor
into the indoor, thereby ensuring the high safety.
1. An air conditioner (1) having a compressor (21), a condenser (23, 11), pressure-reducing
means (15) and an evaporator (11, 23) which are successively connected to one another
in this order to construct a refrigeration cycle, characterized in that a prescribed
smell element is added to refrigerant which is filled in said refrigeration cycle.
2. The air conditioner as claimed in claim 1, wherein said prescribed smell element provides
irritant smell to the refrigerant.
3. The air conditioner as claimed in claim 1, wherein said prescribed smell element is
inactive to the refrigerant, and it does not corrode the constituent elements of said
refrigeration cycle.
4. An air conditioner (1) having a compressor (21), a condenser (23, 11), pressure-reducing
means (15) and an evaporator (11, 23) which are successively connected to one another
in this order to construct a refrigeration cycle, characterized in that a prescribed
dye is added to at least one of refrigerant and refrigeration machine oil which are
filled in said refrigeration cycle.
5. The air conditioner as claimed in claim 4, wherein said dye provides said at least
one of refrigerant or refrigeration machine oil with bright color.
6. The air conditioner as claimed in claim 4, wherein said dye is inactive to the refrigerant,
and does not corrode the constituent elements of said refrigeration cycle.
7. An air conditioner (1) having a compressor (21), a condenser (23, 11), pressure-reducing
means (15) and an evaporator (11, 13) which are successively connected to one another
in this order to construct a refrigeration cycle, flammable refrigerant being filled
in said refrigeration cycle, characterized by including:
leakage detection means (57) for detecting leakage of the refrigerant from said refrigeration
cycle; and
means (51) for stopping the operation of said compressor (21) when the leakage of
the refrigerant is detected by said leakage detection means (57).
8. The air conditioner as claimed in claim 7, further including plural cut-off valves
(61, 63) in said refrigeration cycle, wherein said cut-off valves (61, 63) are closed
to separate the leakage position of the refrigerant from said refrigeration cycle
when the leakage of the refrigerant is detected by the leakage detection means (57).
9. The air conditioner as claimed in claim 7, further including:
a partition plate (5) for partitioning into an indoor space (7) and an outdoor space
(9) a single case in which the constituent elements of said refrigeration cycle are
accommodated;
an air flow port (65) which is provided to said partition plate (5) and allows air
to flow therethrough between the indoor space (7) and the outdoor space (9);
a damper 67) for closing and opening said air flow port; and
means (51) for opening said damper (67) to validate said air flow port (65) when the
refrigerant leakage is detected by said leakage detection mean (57).