FIELD OF THE INVENTION
[0001] The present invention concerns the field of laundry drying machines equipped with
a heat pump system comprising a refrigerant loop.
[0002] In particular, the present invention concerns the field of preventing and/or reducing
the risks deriving from an abnormal working condition, in particular the risk caused
by a refrigerant leakage.
[0003] The present invention refers also to a method for operating such laundry drying machine.
BACKGROUND ART
[0004] Laundry drying machines capable of carrying out a drying process on laundry, hereinafter
simply indicated as laundry dryers, generally comprise a casing that houses a laundry
container, like a rotating drum, where laundry to be treated is received. A closed
air stream circuit carries out drying operation by circulating hot air through the
laundry container containing the wet laundry.
[0005] In laundry dryers, the heat pump technology is the most efficient way to save energy
during drying operation. In conventional heat pump laundry dryers a drying air stream
flows in a close loop. The drying air stream is moved by a fan, passes the laundry
drum and removes water from wet clothes. Then the drying air stream is cooled down
and dehumidified and then heated up in a heat pump system and finally reinserted again
into the laundry drum.
[0006] The heat pump system comprises a refrigerant flowing in a closed-loop refrigerant
circuit realized with pipes and comprising a compressor, a condenser, an expansion
device and an evaporator. The condenser heats up the drying air while the evaporator
cools and dehumidifies the drying air leaving the drum. The refrigerant flows in the
refrigerant circuit where it is compressed by the compressor, condensed in the condenser,
expanded in the expansion device and then vaporized in the evaporator. The temperatures
of the drying air stream and the refrigerant are strongly correlated to each other.
[0007] Refrigerants which are used or could be used in the refrigerant circuit comprise
substances like as Hydro Fluoro Carbon (HFC), Hydro Fluoro Olefine (HFO), Hydro Carbon
(HC). Common HFC refrigerants are R134a and R407c and common HC refrigerants are R290
and R600a. Carbon dioxide (CO
2), ammonia (NH
3) could be also.
[0008] A drawback of the known technique using a closed-loop refrigerant circuit derives
from risks of leakage in case of failure of some components of the heat pump system,
for example in the case that the condenser or the refrigerant pipes are damaged.
[0009] A laundry dryer belonging to the know technique implementing refrigerant leakage
detecting means is disclosed in document
US20120079736.
[0010] In this document, a laundry dryer capable of rapidly and easily detecting whether
refrigerant leakage has occurred or not is disclosed.
[0011] If it is determined that refrigerant leakage has occurred, the compressor is stopped
and an alarm may be displayed in a display apparatus disposed on a front surface of
the machine.
[0012] However, the technique above described belonging to the known art still poses some
drawbacks.
[0013] A drawback of this known technique derives from risks for people health in case of
leakage due to the failure of some components of the heat pump system.
[0014] In laundry dryers of known type, in fact, an alarm is sent only after a failure is
occurred. The refrigerant may therefore evaporate and its diffusion and interaction
in the air may affect the environment.
[0015] Even if the compressor is stopped and/or an alarm is displayed, part or whole the
refrigerant flowing in the refrigerant circuit may leak thus determining dangerous
situation, like risk of exposure to toxic gases and/or fire and/or explosions of the
refrigerant itself.
[0016] It is an object of the invention to implement a laundry drying machine equipped with
a heat pump system where the risks due to refrigerant leakage are reduced compared
to known laundry drying machines.
[0017] The heat pump laundry dryer of
EP 2 527 521 A1 has an evaporator, a condenser, a compressor and an expansion device. The refrigerant
to be used is CO
2 where after a heat-up phase during the stationary phase very high refrigerant pressures
are achieved. Due to this high pressure, abnormal conditions may occur which may damage
the heat pump circuit. It is suggested to use at least one valve by which a portion
of the CO
2 can be isolated from the refrigerant circuit of the heat pump system as soon as the
heat-up phase was sufficient as indicated by the refrigerant pressure and/or temperature.
The isolated capture of the refrigerant is made in a refrigerant trap that is connected
via the one or more valves to the refrigerant circuit. By this capture of CO
2 further built-up of pressure may be restricted or limited and a refrigerant leakage
is prevented.
[0018] EP 2 489 775 A1 suggests a heat-pump laundry dryer in which the heat-up phase of the heat pump system
is accelerated by using an additional evaporator during heat-up. Thus in the heat-up
phase the drying air is only heated up by the condenser. After heating-up, the 3/2
way valves change the refrigerant flow from additional evaporator only to main evaporator
only.
[0019] US 2012/0079736 A1 proposes to use a leak detector in a dryer for detecting refrigerant leakage.
DISCLOSURE OF INVENTION
[0020] The invention is defined in claims 1 and 10, respectively.
[0021] The applicant has found that by providing a laundry drying machine of the type comprising
a heat pump system having a refrigerant circuit for a refrigerant and comprising an
air stream circuit for an air stream conveyable to a laundry drum suited to receive
laundry to be dried, wherein the refrigerant circuit comprises: a first heat exchanger
for a thermal coupling between the air stream circuit and the refrigerant circuit;
a second heat exchanger for a further thermal coupling between the air stream circuit
and the refrigerant circuit; a compressor arranged in the refrigerant circuit between
the second heat exchanger and the first heat exchanger; a refrigerant expansion device
arranged in the refrigerant circuit between the first heat exchanger and the second
heat exchanger; and by providing two or more interrupting devices arranged along the
refrigerant circuit suited to define one or more portions of the refrigerant circuit
where the refrigerant may be confined, it is possible to reduce the risks due to refrigerant
leakage.
[0022] The present invention relates to a laundry drying machine of the type comprising
a heat pump system having a refrigerant circuit for a refrigerant and comprising an
air stream circuit for an air stream conveyable to a laundry drum suited to receive
laundry to be dried, said refrigerant circuit comprising:
- a first heat exchanger for a thermal coupling between said air stream circuit and
said refrigerant circuit wherein the refrigerant is cooled down and said air stream
is heated up;
- a second heat exchanger for a further thermal coupling between said air stream circuit
and said refrigerant circuit wherein the refrigerant is heated up and said air stream
is cooled down;
- a compressor arranged in said refrigerant circuit between said second heat exchanger
and said first heat exchanger;
- a refrigerant expansion device arranged in said refrigerant circuit between said first
heat exchanger and said second heat exchanger;
wherein the machine further comprises two or more interrupting devices arranged along
said refrigerant circuit suited to define one or more portions of said refrigerant
circuit where said refrigerant may be confined. The machine further comprises a leakage
sensor, wherein the interrupting devices are activated when a refrigerant leakage
is detected by said leakage sensor.
[0023] Preferably, the machine comprises a control unit for controlling the interrupting
devices.
[0024] In a preferred embodiment of the invention, the interrupting devices comprise on/off
valves.
[0025] More preferably, the on/off valves are normally closed valves so that the refrigerant
is normally confined in said one or more portions when the on/off valves are deactivated
or the machine is switch off.
[0026] Preferably, the refrigerant expansion device comprises an expansion valve and such
expansion is one of the interrupting devices.
[0027] Opportunely, the refrigerant circuit comprises pipes connecting the compressor, the
first heat exchanger, the expansion device and the second heat exchanger in a closed-loop
configuration.
[0028] Preferably, the interrupting devices are arranged along one or more of the connecting
pipes.
[0029] In a preferred embodiment of the invention, the interrupting devices are arranged
in the high-pressure side of the refrigerant circuit.
[0030] The high-pressure side is defined as the portion of the refrigerant circuit comprised
between the compressor outlet and the expansion device inlet.
[0031] More preferably, the interrupting devices are arranged in the high-pressure side
of the refrigerant circuit, preferably in proximity of the first heat exchanger, so
that the refrigerant may be confined therein when the interrupting devices are activated
or deactivated.
[0032] In another preferred embodiment of the invention, the interrupting devices are arranged
in the low-pressure side of the refrigerant circuit.
[0033] The low-pressure side is defined as the portion of the refrigerant circuit comprised
between the expansion device outlet and the compressor inlet. Preferably, the refrigerant
is one of the following types: Hydro Fluoro Carbon type (HFC), Hydro Fluoro Olefine
type (HFO), Hydro Carbon type (HC), Carbon dioxide (CO
2), ammonia (NH
3).
[0034] In a further preferred embodiment of the invention, the machine further comprises
absorber arranged in positions suited to allow absorption of refrigerant which may
leak out from the refrigerant circuit.
[0035] Preferably, the absorber are arranged in a basement portion of the machine.
[0036] In a further aspect the present invention relates to a method for controlling a laundry
drying machine of the type comprising a heat pump system having a refrigerant circuit
for a refrigerant and comprising an air stream circuit for an air stream conveyable
to a laundry drum suited to receive laundry to be dried, said refrigerant circuit
comprising:
- a first heat exchanger for a thermal coupling between said air stream circuit and
said refrigerant circuit wherein the refrigerant is cooled down and said air stream
is heated up;
- a second heat exchanger for a further thermal coupling between said air stream circuit
and said refrigerant circuit wherein the refrigerant is heated up and said air stream
is cooled down;
- a compressor arranged in said refrigerant circuit between said second heat exchanger
and said first heat exchanger;
- a refrigerant expansion device arranged in said refrigerant circuit between said first
heat exchanger and said second heat exchanger;
wherein the method comprises the step of confining said refrigerant in one or more
portions of said refrigerant circuit if an abnormal working condition of said refrigerant
circuit occurs. The abnormal working condition is a refrigerant leakage.
[0037] Preferably, the step of confining the refrigerant in one or more portions of the
refrigerant circuit is carried out controlling two or more interrupting devices arranged
along the refrigerant circuit so that activation or deactivation of the interrupting
devices creates said one or more portions.
[0038] Preferably, the working parameters of the compressor comprise the current and/or
the power absorption of the compressor itself.
[0039] In a preferred embodiment of the invention, the refrigerant leakage is detected by
means of a leakage sensor.
[0040] In a further preferred embodiment of the invention, the refrigerant leakage is determined
analyzing one or more functioning parameters of the laundry drying machine.
[0041] Preferably, the functioning parameters comprise one of the parameters selected from
a group comprising: the air stream temperature upstream and/or downstream of said
drum, the temperature measured from a surface of the first heat exchanger, the detected
or calculated pressure and/or temperature of the refrigerant.
[0042] Opportunely, the method further comprises the step of emitting a warning alarm for
the user.
[0043] Preferably, the method further comprises the step of deactivating the compressor
if said abnormal working condition occurs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Further characteristics and advantages of the present invention will be highlighted
in greater detail in the following detailed description of preferred embodiments of
the invention, provided with reference to the enclosed drawings. In said drawings:
- Figure 1 shows a perspective view of a laundry drying machine with an upright side
removed according to a preferred embodiment of the invention;
- Figure 2 illustrates a schematic diagram of the laundry drying machine of Figure 1;
- Figure 3 illustrates a schematic diagram of a laundry drying machine according to
another preferred embodiment of the invention;
- Figure 4 illustrates a schematic diagram of a laundry drying machine according to
a further preferred embodiment of the invention;
- Figure 5 shows a perspective view of the basement for a laundry drying machine realized
according to the diagram of Figure 4;
- Figure 6 illustrates a schematic diagram of a laundry drying machine according to
a further preferred embodiment of the invention;
- Figure 7 illustrates a schematic diagram of a laundry drying machine according to
a further preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0045] The present invention has proved to be particularly successful when applied to a
front-loading drying machine with a rotatable laundry container; however it is clear
that the present invention can be applied as well to a top-loading drying machine
and also to laundry drying machines of cabinet type, i.e. laundry drying machines
where the laundry container does not rotate.
[0046] Furthermore, the present invention can be usefully applied to all the machines requiring
a drying phase for wetted clothes, like as a combined laundry washing and drying machine.
[0047] In the present description the term "laundry drying machine" will refer to both simple
laundry drying machines and laundry washing-drying machines.
[0048] Figures 1 and 2 illustrate a laundry drying machine 1, or laundry dryer, with a heat
pump system 20 according to a first embodiment of the present invention.
[0049] The laundry dryer 1 preferably comprises, though not necessarily, a substantially
parallelepiped-shaped outer boxlike casing 2 which is preferably structured for resting
on the floor. A laundry container consisting of a rotatably drum 9 is provided within
the casing 2. A front door 8, pivotally coupled to the front upright side wall 2a,
is provided for allowing access to the drum interior region to place laundry to be
dried therein.
[0050] The drum 9 is advantageously rotated by a drum motor, preferably an electric motor,
which preferably transmits the rotating motion to the shaft of the drum 9, advantageously
by means of a belt/pulley system. In a different embodiment of the invention, the
drum motor can be directly associated with the shaft of the drum 9.
[0051] A user control interface 15 is preferably arranged on the top of the casing 2. The
user control interface 15 is preferably accessible to the user for the selection of
the drying cycle and insertion of other parameters, for example the type of fabric
of the load, the degree of dryness, etc.. The user control interface 15 preferably
displays machine working conditions, such as the remaining cycle time, alarm signals,
etc. For this purpose the user control interface 15 preferably comprises a display
13.
[0052] In different embodiments, for example in a combined laundry washing and drying machine,
the user may selects and inserts other types of parameters, for example the washing
temperature, the spinning speed, etc..
[0053] In further embodiments, the user control interface may be differently realized, for
example remotely arranged in case of a remote-control system.
[0054] The laundry dryer 1 is provided with an air stream circuit 10, as illustrated in
Figure 2, which is structured to circulate inside the drum 9 a stream of hot air A.
The hot air circulates over and through the laundry located inside the drum 9 to dry
the laundry. The drum 9 itself is therefore part of the air stream circuit 10. The
air stream circuit 10 is also structured for drawing moist air from the drum 9, cooling
down the moist air leaving the drum 9 so to extract and retain the surplus moisture.
The dehumidified air is then heated up to a predetermined temperature preferably higher
than that of the moist air arriving from the drum 9. Finally the heated, dehumidified
air is conveyed again into the drum 9, where it flows over and through the laundry
stored inside the rotatable drum 9 to rapidly dry the laundry, as said above.
[0055] The air stream circuit 10 forms therefore a closed-loop for the air A, as schematically
illustrated with dashed line in Figure 2.
[0056] A fan 12 is preferably arranged along the circuit 10 for generating the air stream
A, more preferably upstream of the drum 9. The fan 12 is adapted and designed for
circulating the air within the air stream circuit 10.
[0057] Preferably, and more particularly, the air stream circuit 10 comprises a dehumidifying
unit 23 arranged downstream of the drum 9 and a heater unit 21 arranged downstream
of the dehumidifying unit 23 and upstream of the drum 9. It is underlined that in
the present application the terms "upstream" and "downstream" are referred to the
flowing direction of the air, heated air and/or moist air, during the standard functioning
of the laundry dryer; for example saying that the fan is arranged upstream of the
drum means that in the standard functioning of the laundry dryer the air firstly passes
through the fan and then flows into the drum; saying that the dehumidifying unit is
arranged downstream of the drum means that in the standard functioning of the laundry
dryer the air firstly circulates inside the drum and then passes through the dehumidifying
unit. In the dehumidifying unit 23 the moist air condenses and cools down and the
water generated therein is preferably collected in a removable container, not illustrated,
arranged below the dehumidifying unit 23.
[0058] In the preferred embodiment here described, the dehumidifying unit 23 is the evaporator
of the heat pump system 20 and the heating unit 21 is the condenser of said heat pump
system 20.
[0059] Therefore, the evaporator 23 dehumidifies the moist air coming from the drum 9 and
then the condenser 21 heats up the dehumidified air coming from the evaporator 23.
The heated air is then conveyed again into the drum 9.
[0060] In further embodiments, the air stream circuit may not form a closed-loop. In this
case, for example, the air stream may be conveyed to a condenser from outside, then
conveyed into the drum, from the drum conveyed to the evaporator and finally expelled
to the outside.
[0061] The heat pump system 20 with its evaporator 23 and condenser 21, therefore, interacts
with the air stream circuit 10. In fact, the air stream circuit 10 and the heat pump
system 20 are thermally coupled by the condenser 21 and the evaporator 23.
[0062] In particular, the heat pump system 20 advantageously comprises a refrigerant circuit
30 forming a closed-loop circuit where a refrigerant flows.
[0063] The refrigerant circuit 30 comprises a compressor 24, a first heat exchanger 21,
i.e. the condenser 21 in the preferred embodiment here described, an expansion device
22 and a second heat exchanger 23, i.e. the evaporator 23 in the preferred embodiment
here described. The compressor 24, the condenser 21, the expansion device 22 and the
evaporator 23 are connected in series to form said closed-loop circuit.
[0064] The refrigerant flows in the refrigerant circuit 30 wherein is compressed by the
compressor 24, condensed in the condenser 21, expanded in the expansion device 22
and then vaporized in the evaporator 23.
[0065] The expansion device 22 preferably comprises a capillary tube, as visible in Figure
5. In different embodiments, the expansion device may comprise a controlled expansion
valve, more preferably an electronic expansion valve, as will be illustrated below
with reference to embodiment of Figure 7.
[0066] Refrigerants which may be used in the refrigerant circuit 30 comprise substances
like as Hydro Fluoro Carbon (HFC), Hydro Fluoro Olefine (HFO) and Hydro Carbon (HC).
Common HFC refrigerants are R134a and R407c and common HC refrigerants are R290 and
R600a.
[0067] In different embodiments, the first heat exchanger may comprises a gas cooler (instead
of the condenser) and the second heat exchanger may comprises a gas heater (instead
of the evaporator). In this case the refrigerant is advantageously a gas, such as
Carbon dioxide CO
2 or ammonia (NH
3), which maintains its gaseous state along all the closed-loop circuit, and in particular
in the gas cooler and in the gas heater. In this type of heat pump system the gas
temperature changes while passing through the gas cooler and the gas heater.
[0068] Generally, the first heat exchanger 21 defines a thermal coupling between the air
stream circuit 10 and the refrigerant circuit 30 wherein the refrigerant is cooled
down and the air stream A is heated up.
[0069] Analogously, the second heat exchanger 23 defines a further thermal coupling between
the air stream circuit 10 and the refrigerant circuit 30 wherein the refrigerant is
heated up and the air stream A is cooled down.
[0070] The portion of the refrigerant circuit 30 comprised between the compressor outlet
24b and the expansion device inlet 22a defines a high-pressure side wherein the refrigerant
is compressed at a high pressure (for example 15-20 bars when the refrigerant used
is R290).
[0071] On the other hand, the portion of the refrigerant circuit 30 comprised between the
expansion device outlet 22b and the compressor inlet 24a defines a low-pressure side
wherein the refrigerant is expanded at a low pressure (for example 6-10 bars when
the refrigerant used is R290).
[0072] More preferably, the components of the refrigerant circuit 30 (i.e. the compressor
24, the condenser 21, the expansion device 22 and the evaporator 23) are connected
one to the other by means of respective pipes 61, 62, 63 and 64. More preferably,
the first pipe 61 connects the compressor outlet 24b to the condenser inlet 21a, the
second pipe 62 connects the condenser outlet 21b to the expansion device inlet 22a,
the third pipe 63 connects the expansion device outlet 22b to the evaporator inlet
23a and the fourth pipe 64 connects the evaporator outlet 23b to the compressor inlet
24a.
[0073] Preferably said connections between pipes and components of the refrigerant circuit
30 are obtained by a welding process.
[0074] Further, the laundry dryer 1 may comprise several kinds of sensor elements, which
are not shown in the figures. For example, the sensor elements may be provided for
detecting the temperature, the relative humidity and/or the electrical impedance at
suitable positions of the laundry dryer 1. Furthermore, the sensor element may preferably
comprise a leakage sensor. The leakage sensor is preferably positioned in a bottom
portion 14 of the laundry dryer 1. The leakage sensor preferably comprises: catalytic
sensors, semiconductors sensors, electrochemical sensors, thermal conductivity sensors,
infrared sensors. The type of sensor to use is selected in relation to the refrigerant
fluid to detect. For example, when the refrigerant is CO
2 the infrared sensors are preferably used. Preferably, the sensor type has to be selected
on the base of the level of sensibility determined by refrigerant fluid to detect.
[0075] The laundry dryer 1 further preferably comprises a central processing unit, not illustrated,
advantageously connected to the various parts of laundry dryer 1, or peripheral units,
in order to ensure its operation.
[0076] According to the preferred embodiment of the invention here illustrated, along the
refrigerant circuit 30 are arranged two interrupting devices 71, 72. The two interrupting
devices 71, 72 are preferably arranged in the high-pressure side of the refrigerant
circuit 30.
[0077] The first interrupting device 71 is preferably arranged along the first pipe 61 and
the second interrupting device 72 is preferably arranged along the second pipe 62.
[0078] The first interrupting device 71 divides the first pipe 61 into two portions 61a
and 61b. The second interrupting device 72 divides the second pipe 62 into two portions
62a and 62b.
[0079] The interrupting devices 71, 72 are advantageously connected to a control unit 26.
The control unit 26 controls the activation/deactivation of the interrupting devices
71, 72.
[0080] The control unit 26 for controlling the interrupting devices 71, 72 can be part of
the central processing unit.
[0081] The interrupting devices 71, 72 preferably comprise on/off valves which control the
flow of the refrigerant within the pipes 61 and 62, and therefore the flow of the
refrigerant within the refrigerant circuit 30.
[0082] More preferably, the interrupting devices 71, 72 comprise solenoid operated valves.
[0083] In different embodiments, nevertheless, the interrupting devices may be of different
types, like as step motor valves.
[0084] In the preferred embodiment here described, with "valve activated" it is meant that
the valve is ON, or energized, and the refrigerant may flow (i.e. the valve is open).
With "valve deactivated" it is meant that the valve is OFF, or de-energized, and the
refrigerant may not flow (i.e. the valve is closed and the refrigerant flow is interrupted).
[0085] Still more preferably, the valves 71, 72 are normally-closed valves. In this case,
when either the laundry dryer 1 or the control unit 26 is switch off, each valve 71,
72 is deactivated , or de-energized, and therefore in its closed condition. When the
laundry dryer 1 and the control unit 26 are both switch on and ready to start a drying
cycle, both the valves 71, 72 are activated by the control unit 26. The refrigerant
may flow along the refrigerant circuit 30 and the drying cycle can be normally carried
out until its completion.
[0086] In particular, the laundry to be dried is first placed inside the drum 9. By operating
on the interface unit 15 the user selects the desired drying cycle depending, for
example, on the type of laundry textile to dry or on the dryness degree of the laundry
which is expected at the end of the cycle, for example totally dried or with residual
moisture for a best ironing.
[0087] Once the user has selected the desired drying cycle, the central processing unit
sets the laundry drying machine 1 so that it starts the drying cycle.
[0088] In a further embodiment, the selection of the desired drying cycle may be performed
before placing the laundry into the drum 9.
[0089] In normal condition, the selected drying cycle is performed until its completion,
as said above.
[0090] On the contrary, and according to the invention, if an abnormal condition of the
refrigerant circuit 30 occurs, the valves 71, 72 are deactivated. Both the valves
71, 72 are closed and the refrigerant flow is being interrupted.
[0091] An abnormal condition may comprise one or more working conditions of the laundry
dryer 1 which differ from the normal condition of the same.
[0092] Preferably, abnormal conditions may preferably comprise one of the following conditions
which affect the refrigerant circuit 30.
[0093] In a first preferred embodiment, an abnormal condition is determined by working parameters
of the compressor 24 which exceed pre-determined safety thresholds. Preferably, the
working parameters of the compressor 24 comprise current and/or power absorption of
the compressor 24 itself.
[0094] In further first preferred embodiment, an abnormal condition is determined by the
refrigerant temperature or pressure which exceed pre-determined safety thresholds.
[0095] Furthermore, an abnormal condition is also determined by sudden changes of said parameters,
for example sudden changes of current and/or power absorption of the compressor 24
or sudden changes of the refrigerant temperature or pressure.
[0096] An abnormal condition may then preferably refer to a refrigerant leakage which is
directly and advantageously detected by a leakage sensor, if present.
[0097] In different embodiments, detection of refrigerant leakage is determined analyzing
one or more functioning parameters of the laundry dryer 1, for example analyzing the
drying air temperature upstream and/or downstream of the drum 9, the temperature measured
from the surface of the condenser 21, the detected or calculated pressure or temperature
of the refrigerant. A method which uses said parameters for the detection of a refrigerant
leakage is disclosed, for example, in the known document
US20120079736.
[0098] In further different embodiments, it is considered quite probable that a refrigerant
leakage occurs when the above mentioned parameters of the compressor exceed pre-determined
safety thresholds and/or when the refrigerant temperature or pressure exceed pre-determined
safety thresholds.
[0099] Furthermore, once the valves 71, 72 are deactivated the compressor 24 is also preferably
deactivated.
[0100] The compressor 24 is preferably deactivated when the valves 71, 72 are deactivated
or just after a short period of time. In different embodiments, the compressor 24
may be deactivated after a pre-determined lapse of time.
[0101] At the same time, preferably, a warning alarm is emitted for the user, for example
a visual alarm at the display 13 or an acoustic alarm. More preferably, a message
alarm to call the service is advantageously displayed.
[0102] According to the invention, therefore, when an abnormal condition of the refrigerant
circuit 30 occurs the refrigerant is advantageously prevented from flowing along the
refrigerant circuit 30 by the closed valves 71, 72.
[0103] More particularly, a first quantity of the refrigerant is confined by the closed
valves 71, 72 in the path defined by the second portion 61b of the first pipe 61,
the condenser 21 and the first portion 62a of the second pipe 62. The remaining second
quantity of refrigerant is confined by the closed valves 71, 72 in the path defined
by the second portion 62b of the second pipe 62, the expansion device 22, the third
pipe 63, the evaporator 23, the fourth pipe 64, the compressor 24 and the first portion
61a of the first pipe 61.
[0104] Advantageously, if the abnormal condition is caused by a refrigerant leakage in a
point of the refrigerant circuit 30, the quantity of refrigerant leaving the refrigerant
circuit 30 is not the total amount of refrigerant contained in the refrigerant circuit
30 but rather only the first or the second quantity of the same, depending on the
point in the refrigerant circuit 30 where the leakage occurs. For example, if a condenser
failure causes a refrigerant leakage therein, only the second quantity of refrigerant
confined by the closed valves 71, 72 leaves the refrigerant circuit 30. Analogously,
if a failure in the fourth pipe 64 occurs thus causing a refrigerant leakage therein,
only the first quantity of refrigerant confined by the closed valves 71, 72 leaves
the refrigerant circuit 30.
[0105] According to the invention, therefore, the provision of two interrupting devices
71, 72 advantageously allows the reduction of the refrigerant which may leave the
refrigerant circuit 30 when a leakage occurs. In other words, the provision of two
interrupting devices 71, 72 advantageously prevents all the refrigerant leaking out
the from the refrigerant circuit 30.
[0106] This, in turn, reduces the risks deriving from the refrigerant leaked out from the
refrigerant circuit 30, like the risk of exposure to toxic gases, fire and/or explosions
of the refrigerant.
[0107] This is particularly advantageous if Hydro Carbon (HC) is used as refrigerant. Hydro
Carbon (HC), in fact, is a substance particularly toxic and flammable.
[0108] Nevertheless, even when other refrigerants less dangerous are used, like as Hydro
Fluoro Carbon (HFC), Hydro Fluoro Olefine (HFO), Carbon dioxide CO
2 or ammonia (NH
3), the provision of two interrupting devices 71, 72 advantageously allows the reduction
of the refrigerant which may leave the refrigerant circuit 30 when a leakage occurs.
[0109] Furthermore, the remaining refrigerant confined in the refrigerant circuit 30 between
the interrupting devices 71, 72 may be advantageously recycled and/or subjected to
a disposal process.
[0110] Evaporation and diffusion of the refrigerant in the air is therefore advantageously
avoided.
[0111] Furthermore, even when a refrigerant leakage has not yet occurred, the deactivation
of the two interrupting devices 71, 72 as a consequence of an abnormal working condition,
for example a compressor failure and/or a high temperature of the refrigerant, creates
two confined portions for the refrigerant inside the refrigerant circuit 30. This
is a favourable configuration which may reduce the risks for imminent or future damaging
that may occur as consequence of said abnormal working condition. A risk prevention
is therefore performed. As a consequence of what described above, it follows that
the more the interrupting devices arranged along the refrigerant circuit are, the
less the quantity of refrigerant which may leak out from the refrigerant circuit is.
Preferably, as said above, the interrupting devices are placed in the high-pressure
side of the refrigerant circuit. In fact, due to the high pressure of the refrigerant,
this side comprises the most relevant quantity of the refrigerant. In particular,
the condenser 21 contains a high percentage of the refrigerant, typically more than
50% of the total amount.
[0112] For this reason, preferably, the interrupting devices are arranged in the high-pressure
side of the refrigerant circuit in proximity of the condenser, so that more than 50%
of the refrigerant may be confined therein when the interrupting devices are activated.
[0113] A further embodiment of the heat pump system 120 according to the invention which
utilizes more than two interrupting devices 71, 72 is shown in figure 3.
[0114] Here, further the two interrupting devices 71, 72 as previously disclosed, a third
interrupting device 171 and a fourth interrupting device 172 are arranged along the
refrigerant circuit 130. The two interrupting devices 171, 172 are arranged in the
low-pressure side of the refrigerant circuit 130.
[0115] The third interrupting device 171 is preferably arranged along the third pipe 63
and the fourth interrupting device 172 is preferably arranged along the fourth pipe
64.
[0116] The third interrupting device 171 divides the third pipe 63 into two portions 63a
and 63b. The fourth interrupting device 172 divides the fourth pipe 64 into two portions
64a and 64b.
[0117] The interrupting devices 171, 172 are advantageously connected to the control unit
26 which controls the activation/deactivation of the same.
[0118] The interrupting devices 171, 172 preferably comprise on/off valves.
[0119] In this embodiment and analogously to the first embodiment previously described,
if an abnormal condition occurs, the valves 71, 72, 171, 172 are deactivated. The
valves 71, 72, 171, 172 are closed and the refrigerant flow is being interrupted.
[0120] More particularly, the refrigerant is now confined by the closed valves 71, 72, 171,
172 in respective four portions. Each portion may contain, for example, a fourth of
the total amount of refrigerant.
[0121] Advantageously, if a refrigerant leakage in a point of the refrigerant circuit 130
occurs, the quantity of refrigerant which may leave the refrigerant circuit 130 is
less than the total amount of refrigerant contained in the refrigerant circuit 130,
and in particular only a quarter of the total amount.
[0122] For example, if a condenser failure causes a refrigerant leakage therein, only the
quantity (one fourth of the total) of refrigerant confined by the closed valves 71,
72 leaves the refrigerant circuit 130.
[0123] According to the invention, therefore, the provision of interrupting devices 71,
72, 172, 172 advantageously allows the reduction of the refrigerant which may leave
the refrigerant circuit 130 when a leakage occurs.
[0124] This, in turn, reduces the risks deriving from the refrigerant leaked out from the
refrigerant circuit 130, like the risk of exposure to toxic gases, fire and/or explosions
of the refrigerant.
[0125] The remaining refrigerant confined in the refrigerant circuit 130 between the interrupting
devices 71, 72, 172, 172, then, may be advantageously recycled and/or subjected to
a disposal process.
[0126] Furthermore, when a refrigerant leakage has not yet occurred, the deactivation of
the interrupting devices 71, 72, 171, 172 as a consequence of an abnormal working
condition, for example a compressor failure and/or a high temperature of the refrigerant,
creates four confined portions for the refrigerant inside the refrigerant circuit
130. This is a favourable configuration which may reduce the risks for imminent or
future damaging that may occur as consequence of said abnormal working condition.
A risk prevention is therefore performed.
[0127] A further embodiment of the present invention is described with reference to figures
4 and 5.
[0128] Figure 4 shows a schematic diagram of a laundry dyer 1 with a heat pump system 220
according to this embodiment.
[0129] Almost all the components of the laundry dryer 1 here illustrated are the same described
and illustrated in the previous embodiments.
[0130] The laundry dryer 1 comprises an air stream circuit 10. The air stream circuit 10
is a closed-loop air stream circuit 10 structured to circulate inside the drum 9 a
stream of hot air A.
[0131] A fan 12 is preferably arranged along the circuit 10. The air stream circuit 10 then
comprises a dehumidifying unit 23 (evaporator) arranged downstream of the drum 9 and
a heater unit 21 (condenser) arranged downstream of the dehumidifying unit 23 and
upstream of the drum 9.
[0132] In further embodiments, the air stream circuit may not form a closed-loop. In this
case, for example, the air stream may be conveyed to a condenser from outside, then
conveyed into the drum, from the drum conveyed to the evaporator and finally expelled
to the outside.
[0133] The heat pump system 220 with its evaporator 23 and condenser 21, therefore, interacts
with the air stream circuit 10. In fact, the air stream circuit 10 and the heat pump
system 220 are thermally coupled by the condenser 21 and the evaporator 23.
[0134] In particular, the heat pump system 220 advantageously comprises a refrigerant circuit
230 forming a closed-loop circuit where a refrigerant flows.
[0135] The refrigerant circuit 230 comprises a compressor 24, a first heat exchanger 21,
i.e. the condenser 21 in the preferred embodiment here described, an expansion device
22 and a second heat exchanger 23, i.e. the evaporator 23 in the preferred embodiment
here described. The compressor 24, the condenser 21, the expansion device 22 and the
evaporator 23 are connected in series to form said closed-loop circuit.
[0136] The refrigerant flows in the refrigerant circuit 230 wherein is compressed by the
compressor 24, condensed in the condenser 21, expanded in the expansion device 22
and then vaporized in the evaporator 23.
[0137] Refrigerants which may be used in the refrigerant circuit 230 comprise substances
like as Hydro Fluoro Carbon (HFC), Hydro Fluoro Olefine (HFO) and Hydro Carbon (HC).
Common HFC refrigerants are R134a and R407c and common HC refrigerants are R290 and
R600a.
[0138] In different embodiments, the first heat exchanger may comprises a gas cooler (instead
of the condenser) and the second heat exchanger may comprises a gas heater (instead
of the evaporator). In this case the refrigerant is advantageously a gas, such as
Carbon dioxide CO
2 or ammonia (NH
3), which maintains its gaseous state along all the closed-loop circuit, and in particular
in the gas cooler and in the gas heater. In this type of heat pump system the gas
temperature changes while passing through the gas cooler and the gas heater.
[0139] Generally, the first heat exchanger 21 defines a thermal coupling between the air
stream circuit 10 and the refrigerant circuit 230 wherein the refrigerant is cooled
down and the air stream A is heated up.
[0140] Analogously, the second heat exchanger 23 defines a further thermal coupling between
the air stream circuit 10 and the refrigerant circuit 230 wherein the refrigerant
is heated up and the air stream A is cooled down.
[0141] According to the invention, the laundry dryer 1 comprises absorbers, schematically
shown with the grey square 500 surrounding the refrigerant circuit 230 in Figure 4
.
[0142] The absorbers 500 are opportunely arranged in the laundry dryer 1 to absorb the major
quantity of refrigerant which may leak out from the refrigerant circuit 230. The absorbers
500 are preferably arranged to cover and/or surround the most critical part or the
potential source of leakages of the laundry dryer 1.
[0143] In a preferred embodiment, the absorbers 500 are arranged in close proximity to the
heat exchangers 21, 23, more preferably around the first heat exchanger 21. In a further
preferred embodiment, the absorbers 500 are arranged in close proximity to the pipe
connections, in particular at welded joints thereof.
[0144] In another preferred embodiment, the absorbers 500 are arranged at the compressor
outlet 24a where the refrigerant pressure along the refrigerant circuit 30 is typically
at its maximum value and therefore a critical point.
[0145] In preferred embodiments, the absorbers 500 are preferably placed into one or more
side walls of the casing 2 or into the basement 14. In other embodiments, the absorbers
may be preferably placed in the opening of the laundry dryer 1 where air is exchange
with the environment.
[0146] The absorbers 500 are preferably made with active carbon, or synthetic absorbers
or inorganic absorber materials or polymers absorbers.
[0147] The absorbers 500 preferably may are in the form of a sheet or a cartridges or sponges,
etc.
[0148] To avoid flammability or explosion problems related to the accumulation of the leaked
refrigerant in the absorbers 500, the absorbers 500 are preferably at least partially
filled with fireproof compounds. Alternatively, the absorption capacity (dimension
and internal shape) of the absorbers 500 is maintained under a prefixed value so that
to maintain it safe from flammability or explosion.
[0149] If a refrigerant leakage occurs, part or all the leaked refrigerant is advantageously
absorbed by the absorbers 500.
[0150] At the same time, preferably, a warning alarm is emitted for the user, for example
a visual alarm at the display 13 or an acoustic alarm. More preferably, intervention
of the service is necessary.
[0151] Advantageously the absorbers 500 will be regenerated or replaced by the service.
Regeneration of the absorbers 500 could be easily done by heating. Replacement operations
of the absorbers 500 may therefore be simple and fast.
[0152] Figure 5 illustrates preferred positions P where the absorbers 500 (sheet, sponges,
cartridges, etc) may be arranged.
[0153] In the figure, the basement 14 of the laundry drier 1 is illustrated removed from
the rest.
[0154] Most of the components of the air stream circuit 10 and of the heat pump system 220
are arranged in basement 14. The basement 14 is preferably made of polymeric material.
[0155] The basement 14 preferably comprises a lower shell 54 and an upper shell 55, opportunely
coupled one to the other.
[0156] In particular, the basement 14 receives the condenser 21, the expansion device 22
(capillary tube), the evaporator 23, the compressor 24 and the connecting pipes. The
basement 14 also preferably receives the fan 12, not visible, in a seat 12a. The basement
14 then also preferably receives a cooling-air fan, not visible, which advantageously
conveys a cooling air stream inside the basement 14, and in particular an air stream
for cooling the compressor 24.
[0157] The basement 14 of the dryer 1 is also opportunely shaped to form air paths for the
air stream circuit 10. Such air paths opportunely convey the air across the heat exchangers,
i.e. the condenser 21 and the evaporator 23.
[0158] Positions P are preferred places where the absorbers according to the invention may
be placed.
[0159] Preferably, the absorbers are arranged in the lower shell 54 of the basement, more
preferably around the heat exchangers 21, 23 and the compressor 24.
[0160] Figure 6 shows a schematic diagram of a laundry dyer 1 according to a further embodiment
of the invention.
[0161] This embodiment shows a combination of the previous embodiment described with reference
to figure 3 and the embodiment described with reference to Figure 4. The laundry dryer
1 hence comprises both the interrupting devices 71, 72, 171, 172 and the absorbers
500.
[0162] Advantageously, the provision of interrupting devices 71, 72, 171, 172 advantageously
allows the reduction of the refrigerant which may leave the refrigerant circuit 130
when a leakage occurs and, furthermore, part or all the leaked refrigerant is advantageously
absorbed by the absorbers 500.
[0163] A further embodiment of the heat pump system 320 according to the invention is shown
in figure 7.
[0164] This embodiment differs from the first embodiment illustrated in Figure 2 for the
fact that the expansion device 122 comprises a controlled expansion valve instead
of a capillary tube and the second interrupting device 72 is omitted. The expansion
valve 122 preferably comprises an electronic valve.
[0165] The control unit 26 drives the expansion valve 122 and may modulate therefore the
refrigerant flowing in the refrigerant circuit 330.
[0166] The control unit 26 may also drive the expansion valve 122 until its closure, i.e.
until the refrigerant is prevented from flowing in the in the refrigerant circuit
330.
[0167] In this particular working condition, the expansion valve 122 acts as an interrupting
device.
[0168] In this embodiment, therefore, the interrupting function for the refrigerant flowing
in the refrigerant circuit 330 according to the invention is carried out by the first
interrupting device 71 and the expansion valve 122, which performs therefore the function
of the second interrupting device 72 previously described. It has thus been shown
that the present invention allows the set objects to be achieved. In particular, it
makes it possible to obtain a laundry drying machine having reduced risks due to refrigerant
leakage with respect to the systems of known type.
[0169] Although illustrative embodiments of the present invention have been described herein
with reference to the accompanying drawings, it is to be understood that the present
invention is not limited to those precise embodiments, and that various other changes
and modifications may be affected therein by one skilled in the art. For example,
the laundry dryer may comprise further auxiliary heat exchangers associated to the
heat pump system. All such changes and modifications are intended to be included within
the scope of the invention as defined by the appended claims.
1. A laundry drying machine (1) of the type comprising a heat pump system (20; 120; 220;
320) having a refrigerant circuit (30; 130; 230; 330) for a refrigerant and comprising
an air stream circuit (10) for an air stream (A) conveyable to a laundry drum (9)
suited to receive laundry to be dried, said refrigerant circuit (30; 130; 230; 330)
comprising:
- a first heat exchanger (21) for a thermal coupling between said air stream circuit
(10) and said refrigerant circuit (30; 130; 230; 330) wherein the refrigerant is cooled
down and said air stream (A) is heated up;
- a second heat exchanger (23) for a further thermal coupling between said air stream
circuit (10) and said refrigerant circuit (30; 130; 230; 330) wherein the refrigerant
is heated up and said air stream (A) is cooled down;
- a compressor (24) arranged in said refrigerant circuit (30; 130; 230; 330) between
said second heat exchanger (23) and said first heat exchanger (21);
- a refrigerant expansion device (22; 122) arranged in said refrigerant circuit (30;
130; 230; 330) between said first heat exchanger (21) and said second heat exchanger
(23); and
two or more interrupting devices (71, 72; 171, 172; 122) arranged along said refrigerant
circuit (30; 130; 230; 330) suited to define one or more portions of said refrigerant
circuit (30; 130; 230; 330) where said refrigerant may be confined;
cha
racterized by
a leakage sensor,
wherein said interrupting devices (71, 72; 171, 172; 122) are closed when a refrigerant
leakage is detected by said leakage sensor.
2. A machine (1) according to claim 1, characterized in that it comprises a control unit (26) for controlling said interrupting devices (71, 72;
171, 172; 122).
3. A machine (1) according to claim 1 or 2, characterized in that said two or more interrupting devices (71, 72; 171, 172) comprise on/off valves.
4. A machine (1) according to claim 3, characterized in that said on/off valves are normally closed valves (71, 72; 171, 172) so that said refrigerant
is confined in said one or more portions when said on/off valves (71, 72; 171, 172)
are deactivated or said machine (1) is switch off.
5. A machine (1) according to any preceding claim, characterized in that said refrigerant expansion device (122) comprises an expansion valve, said expansion
valve being one of said interrupting devices (71, 72; 171, 172; 122).
6. A machine (1) according to any preceding claim, characterized in that said refrigerant circuit (30; 130; 230; 330) comprises pipes (61, 62, 63, 64) connecting
said compressor (24), said first heat exchanger (21), said expansion device (22; 122)
and said second heat exchanger (23) in a closed-loop configuration and in that said interrupting devices (71, 72; 171, 172) are arranged along one or more of said
connecting pipes (61, 62, 63, 64).
7. A machine (1) according to any preceding claim, characterized in that said interrupting devices (71, 72; 122) are arranged in the high-pressure side of
said refrigerant circuit (30; 230; 330).
8. A machine (1) according to claim 7, characterized in that said interrupting devices (71, 72; 122) are arranged in said high-pressure side of
said refrigerant circuit (30; 230; 330), so that said refrigerant may be confined
in said first heat exchanger (21).
9. A machine (1) according to any preceding claim, characterized in that said refrigerant is one of the following types: Hydro Fluoro Carbon type (HFC), Hydro
Fluoro Olefine type (HFO), Hydro Carbon type (HC), Carbon dioxide (CO2), ammonia (NH3).
10. A method for controlling a laundry drying machine (1) of the type comprising a heat
pump system (20; 120; 220; 320) having a refrigerant circuit (30; 130; 230; 330) for
a refrigerant and comprising an air stream circuit (10) for an air stream (A) conveyable
to a laundry drum (9) suited to receive laundry to be dried, said refrigerant circuit
(30; 130; 230; 330) comprising:
- a first heat exchanger (21) for a thermal coupling between said air stream circuit
(10) and said refrigerant circuit (30; 130; 230; 330) wherein the refrigerant is cooled
down and said air stream (A) is heated up;
- a second heat exchanger (23) for a further thermal coupling between said air stream
circuit (10) and said refrigerant circuit (30; 130; 230; 330) wherein the refrigerant
is heated up and said air stream (A) is cooled down;
- a compressor (24) arranged in said refrigerant circuit (30; 130; 230; 330) between
said second heat exchanger (23) and said first heat exchanger (21);
- a refrigerant expansion device (22; 122) arranged in said refrigerant circuit (30;
130; 230; 330) between said first heat exchanger (21) and said second heat exchanger
(23);
characterized in that
said method comprises the step of confining said refrigerant in one or more portions
of said refrigerant circuit (30; 130; 230; 330) if an abnormal working condition of
said refrigerant circuit (30; 130; 230; 330) occurs,
wherein said abnormal working condition is a refrigerant leakage
11. The method according to claim 10, characterized in that said step of confining said refrigerant in one or more portions of said refrigerant
circuit (30; 130; 230; 330) is carried out controlling two or more interrupting devices
(71, 72; 171, 172; 122) arranged along said refrigerant circuit (30; 130; 230; 330)
so that activation or deactivation of said interrupting devices (71, 72; 171, 172;
122) creates said one or more portions.
12. The method according to claim 10 or 11, characterized in that said refrigerant leakage is detected by means of a leakage sensor.
13. The method according to claim 10, 11 or 12, characterized in that said refrigerant leakage is determined analyzing one or more functioning parameters
of said laundry drying machine (1).
14. The method according to claim 13, characterized in that said one or more functioning parameters comprise one of the parameters selected from
a group comprising: the air stream temperature upstream and/or downstream of said
drum (9), the temperature measured from a surface of said first heat exchanger (21),
the detected or calculated pressure and/or temperature of said refrigerant.
15. The method according to any preceding claims from 10 to 14, wherein said refrigerant
leakage occurs when
one or more working parameters of said compressor (24) exceed pre-determined safety
thresholds, and/or
the refrigerant temperature and/or the refrigerant pressure exceeds pre-determined
safety thresholds.
16. The method according to claim 15, characterized in that said working parameters of said compressor comprise the current and/or the power
absorption of said compressor (24).
17. The method according to any preceding claim from 10 to 16, characterized in that it further comprises the step of emitting a warning alarm for the user.
18. The method according to any preceding claim from 10 to 17, characterized in that it further comprises the step of deactivating said compressor if said abnormal working
condition occurs.
1. Wäschetrocknungsmaschine (1) des Typs, der ein Wärmepumpensystem (20; 120; 220; 320)
umfasst, das einen Kühlkreislauf (30; 130; 230; 330) für ein Kühlmittel aufweist und
einen Luftströmungskreislauf (10) für eine Luftströmung (A), die einer Wäschetrommel
(9), die zu trocknende Wäsche aufnehmen kann, zugeführt werden kann, umfasst, wobei
der Kühlkreislauf (30; 130; 230; 330) Folgendes umfasst:
- einen ersten Wärmetauscher (21) für eine Wärmekopplung zwischen dem Luftströmungskreislauf
(10) und dem Kühlkreislauf (30; 130; 230; 330), wobei das Kühlmittel herabgekühlt
wird und die Luftströmung (A) aufgeheizt wird;
- einen zweiten Wärmetauscher (23) für eine weitere Wärmekopplung zwischen dem Luftströmungskreislauf
(10) und dem Kühlkreislauf (30; 130; 230; 330), wobei das Kühlmittel aufgeheizt wird
und die Luftströmung (A) herabgekühlt wird;
- einen Kompressor (24), der in dem Kühlkreislauf (30; 130; 230; 330) zwischen dem
zweiten Wärmetauscher (23) und dem ersten Wärmetauscher (21) angeordnet ist;
- eine Kühlmittel-Expansionsvorrichtung (22; 122), die in dem Kühlkreislauf (30; 130;
230; 330) zwischen dem ersten Wärmetauscher (21) und dem zweiten Wärmetauscher (23)
angeordnet ist; und
- zwei oder mehrere Unterbrechungsvorrichtungen (71, 72; 171, 172; 122), die entlang
des Kühlkreislaufs (30; 130; 230; 330) angeordnet sind und einen oder mehrere Abschnitte
des Kühlkreislaufs (30; 130; 230; 330), in denen Kühlmittel eingeschlossen werden
kann, definieren;
gekennzeichnet durch
einen Lecksensor,
wobei die Unterbrechungsvorrichtungen (71, 72; 171, 172; 122) geschlossen sind, wenn
durch den Lecksensor ein Kühlmittelleck detektiert wird.
2. Maschine (1) nach Anspruch 1, dadurch gekennzeichnet, dass sie eine Steuerung (26) zum Steuern der Unterbrechungsvorrichtungen (71, 72; 171,
172; 122) umfasst.
3. Maschine (1) nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass zwei oder mehrere Unterbrechungsvorrichtungen (71, 72; 171, 172) Ein/Aus-Ventile
umfassen.
4. Maschine (1) nach Anspruch 3, dadurch gekennzeichnet, dass die Ein/Aus-Ventile normalerweise geschlossene Ventile (71, 72; 171, 172) sind, so
dass das Kühlmittel in dem einen oder den mehreren Abschnitten eingeschlossen ist,
wenn die Ein/Aus-Ventile (71, 72; 171, 172) deaktiviert sind oder die Maschine (1)
ausgeschaltet ist.
5. Maschine (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Kühlmittel-Expansionsvorrichtung (122) ein Expansionsventil umfasst, wobei das
Expansionsventil eine der Unterbrechungsvorrichtungen (71, 72; 171, 172; 122) ist.
6. Maschine (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Kühlkreislauf (30; 130; 230; 330) eine Leitung (61, 62, 63, 64) umfasst, die
den Kompressor (24), den ersten Wärmetauscher (21), die Expansionsvorrichtung (22;
122) und den zweiten Wärmetauscher (23) in einer Konfiguration eines geschlossenen
Kreislaufs verbindet, und dass die Unterbrechungsvorrichtungen (71, 72; 171, 172)
entlang einer oder mehrerer der Verbindungsleitungen (61, 62, 63, 64) angeordnet sind.
7. Maschine (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Unterbrechungsvorrichtungen (71, 72; 122) auf der Hochdruckseite des Kühlkreislaufs
(30; 230; 330) angeordnet sind.
8. Maschine (1) nach Anspruch 7, dadurch gekennzeichnet, dass die Unterbrechungsvorrichtungen (71, 72; 122) auf der Hochdruckseite des Kühlkreislaufs
(30; 230; 330) angeordnet sind, so dass das Kühlmittel in dem ersten Wärmetauscher
(21) eingeschlossen ist.
9. Maschine (1) nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass das Kühlmittel von einem der folgenden Typen ist: Hydrofluorcarbonat (HFC); Hydrofluorolefin
(HFO); Hydrocarbonat (HC), Kohlenstoffdioxid (CO2), Ammoniak (NH3) .
10. Verfahren zum Steuern einer Wäschetrocknungsmaschine (1) des Typs, der ein Wärmepumpensystem
(20; 120; 220; 320) umfasst, das einen Kühlkreislauf (30; 130; 230; 330) für ein Kühlmittel
aufweist und einen Luftströmungskreislauf (10) für eine Luftströmung (A), die einer
Wäschetrommel (9), die geeignet ist, zu trocknende Wäsche aufzunehmen, zugeführt werden
kann, umfasst, wobei der Kühlkreislauf (30; 130; 230; 330) Folgendes umfasst:
- einen ersten Wärmetauscher (21) für eine Wärmekopplung zwischen dem Luftströmungskreislauf
(10) und dem Kühlkreislauf (30; 130; 230; 330), wobei das Kühlmittel herabgekühlt
wird und die Luftströmung (A) aufgeheizt wird;
- einen zweiten Wärmetauscher (23) für eine weitere Wärmekopplung zwischen dem Luftströmungskreislauf
(10) und dem Kühlkreislauf (30; 130; 230; 330), wobei das Kühlmittel aufgeheizt wird
und die Luftströmung (A) herabgekühlt wird;
- einen Kompressor (24), der in dem Kühlkreislauf (30; 130; 230; 330) zwischen dem
zweiten Wärmetauscher (23) und dem ersten Wärmetauscher (21) angeordnet ist;
- eine Kühlmittel-Expansionsvorrichtung (22; 122), die in dem Kühlkreislauf (30; 130;
230; 330) zwischen dem ersten Wärmetauscher (21) und dem zweiten Wärmetauscher (23)
angeordnet ist;
dadurch gekennzeichnet, dass
das Verfahren den Schritt des Einschließens des Kühlmittels in einem oder mehreren
Abschnitten des Kühlkreislaufs (30; 130; 230; 330) umfasst, falls eine abweichende
Betriebsbedingung des Kühlkreislaufs (30; 130; 230; 330) eintritt,
wobei eine abweichende Betriebsbedingung ein Kühlmittelleck ist.
11. Verfahren nach Anspruch 10, dadurch gekennzeichnet, dass der Schritt des Einschließens des Kühlmittels in einem oder mehreren Abschnitten
des Kühlkreislaufs (30; 130; 230; 330) ausgeführt wird, indem zwei oder mehrere Unterbrechungsvorrichtungen
(71, 72; 171, 172; 122) entlang des Kühlkreislaufs (30; 130; 230; 330) so gesteuert
werden, dass eine Aktivierung oder Deaktivierung der Unterbrechungsvorrichtungen (71,
72; 171, 172; 122) den einen oder die mehreren Abschnitte erzeugt.
12. Verfahren nach Anspruch 10 oder 11, dadurch gekennzeichnet, dass das Kühlmittelleck mittels eines Lecksensors detektiert wird.
13. Verfahren nach Anspruch 10, 11 oder 12, dadurch gekennzeichnet, dass das Kühlmittelleck festgestellt wird, indem ein oder mehrere Funktionsparameter der
Wäschetrocknungsmaschine (1) analysiert werden.
14. Verfahren nach Anspruch 13, dadurch gekennzeichnet, dass der eine oder die mehreren Funktionsparameter einen Parameter umfassen, der aus einer
Gruppe ausgewählt wird, die Folgendes umfasst: die Luftströmungstemperatur stromaufwärts
und/oder stromabwärts der Trommel (9), die Temperatur, die an einer Oberfläche des
ersten Wärmetauschers (21) gemessen wird, der detektierte oder berechnete Druck und/oder
die Temperatur des Kühlmittels.
15. Verfahren nach einem der vorhergehenden Ansprüche 10 bis 14, wobei das Kühlmittelleck
eintritt, wenn ein oder mehrere Betriebsparameter des Kompressors (24) festgelegte
Sicherheitsschwellenwerte überschreiten, und/oder
die Kühlmitteltemperatur und/oder der Kühlmitteldruck festgelegte Sicherheitsschwellenwerte
überschreiten.
16. Verfahren nach Anspruch 15, dadurch gekennzeichnet, dass die Betriebsparameter des Kompressors die Strom- und/oder Leistungsaufnahme des Kompressors
(24) umfassen.
17. Verfahren nach einem der vorhergehenden Ansprüche 10 bis 16, dadurch gekennzeichnet, dass es ferner den Schritt des Ausgebens eines Warnalarms für den Benutzer umfasst.
18. Verfahren nach einem der vorhergehenden Ansprüche 10 bis 17, dadurch gekennzeichnet, dass es ferner den Schritt des Deaktivierens des Kompressors umfasst, falls eine abweichende
Betriebsbedingung eintritt.
1. Machine à sécher le linge (1) du type comprenant un système de pompe à chaleur (20
; 120 ; 220 ; 320) ayant un circuit de fluide frigorigène (30 ; 130 ; 230 ; 330) pour
un fluide frigorigène et comprenant un circuit de flux d'air (10) pour un flux d'air
(A) pouvant être acheminé vers un tambour à linge (9) approprié pour recevoir du linge
à sécher, ledit circuit de fluide frigorigène (30 ; 130 ; 230 ; 330) comprenant :
- un premier échangeur de chaleur (21) pour un accouplement thermique entre ledit
circuit de flux d'air (10) et ledit circuit de fluide frigorigène (30 ; 130 ; 230
; 330), le fluide frigorigène étant refroidi et ledit flux d'air (A) étant chauffé
;
- un second échangeur de chaleur (23) pour un autre accouplement thermique entre ledit
circuit de flux d'air (10) et ledit circuit de fluide frigorigène (30 ; 130 ; 230
; 330), le fluide frigorigène étant chauffé et ledit flux d'air (A) étant refroidi
;
- un compresseur (24) agencé dans ledit circuit de fluide frigorigène (30 ; 130 ;
230 ; 330) entre ledit second échangeur de chaleur (23) et ledit premier échangeur
de chaleur (21) ;
- un dispositif de dilatation de fluide frigorigène (22 ; 122) agencé dans ledit circuit
de fluide frigorigène (30 ; 130 ; 230 ; 330) entre ledit premier échangeur de chaleur
(21) et ledit second échangeur de chaleur (23) ; et
au moins deux dispositifs d'interruption (71, 72 ; 171, 172 ; 122) agencés le long
dudit circuit de fluide frigorigène (30 ; 130 ; 230 ; 330) et appropriés pour définir
une ou plusieurs sections dudit circuit de fluide frigorigène (30 ; 130 ; 230 ; 330)
où ledit fluide frigorigène peut être confiné ;
caractérisé par :
un capteur de fuite,
lesdits dispositifs d'interruption (71, 72 ; 171, 172 ; 122) étant fermés quand une
fuite de fluide frigorigène est détectée par ledit capteur de fuite.
2. Machine (1) selon la revendication 1, caractérisée en ce qu'elle comprend une unité de contrôle (26) pour contrôler lesdits dispositifs d'interruption
(71, 72 ; 171, 172 ; 122).
3. Machine (1) selon la revendication 1 ou 2, caractérisée en ce que les au moins deux dispositifs d'interruption (71, 72 ; 171, 172) comprennent des
vannes d'ouverture/fermeture.
4. Machine (1) selon la revendication 3, caractérisée en ce que lesdites vannes d'ouverture/fermeture sont des vannes normalement fermées (71, 72
; 171, 172) de sorte que ledit fluide frigorigène soit confiné dans ladite ou lesdites
sections quand lesdites vannes d'ouverture/fermeture (71, 72 ; 171, 172) sont désactivées
ou quand ladite machine (1) est éteinte.
5. Machine (1) selon l'une quelconque des revendications précédentes, caractérisée en ce que ledit dispositif de dilatation de fluide frigorigène (122) comprend un détendeur,
ledit détendeur étant un desdits dispositifs d'interruption (71, 72 ; 171, 172 ; 122).
6. Machine (1) selon l'une quelconque des revendications précédentes, caractérisée en ce que ledit circuit de fluide frigorigène (30 ; 130 ; 230 ; 330) comprend des tuyaux (61,
62, 63, 64) raccordant ledit compresseur (24), ledit premier échangeur de chaleur
(21), ledit dispositif de dilatation (22 ; 122) et ledit second échangeur de chaleur
(23) en une configuration en boucle fermée et en ce que lesdits dispositifs d'interruption (71, 72 ; 171, 172) sont agencés le long d'un
ou plusieurs desdits tuyaux de raccord (61, 62, 63, 64).
7. Machine (1) selon l'une quelconque des revendications précédentes, caractérisée en ce que lesdits dispositifs d'interruption (71, 72 ; 122) sont agencés du côté haute pression
dudit circuit de fluide frigorigène (30 ; 230 ; 330).
8. Machine (1) selon la revendication 7, caractérisée en ce que lesdits dispositifs d'interruption (71, 72 ; 122) sont agencés dudit côté haute pression
dudit circuit de fluide frigorigène (30 ; 230 ; 330), de sorte que ledit fluide frigorigène
puisse être confiné dans ledit premier échangeur de chaleur (21).
9. Machine (1) selon l'une quelconque des revendications précédentes, caractérisée en ce que ledit fluide frigorigène est un des types suivants : de type hydrofluorocarboné (HFC),
de type hydrofluoroléfine (HFO), de type hydrocarbure (HC), du dioxyde de carbone
(CO2) et de l'ammoniac (NH3) .
10. Procédé de contrôle d'une machine à sécher le linge (1) du type comprenant un système
de pompe à chaleur (20 ; 120 ; 220 ; 320) ayant un circuit de fluide frigorigène (30
; 130 ; 230 ; 330) pour un fluide frigorigène et comprenant un circuit de flux d'air
(10) pour un flux d'air (A) pouvant être acheminé vers un tambour à linge (9) approprié
pour recevoir du linge à sécher, ledit circuit de fluide frigorigène (30 ; 130 ; 230
; 330) comprenant :
- un premier échangeur de chaleur (21) pour un accouplement thermique entre ledit
circuit de flux d'air (10) et ledit circuit de fluide frigorigène (30 ; 130 ; 230
; 330), le fluide frigorigène étant refroidi et ledit flux d'air (A) étant chauffé
;
- un second échangeur de chaleur (23) pour un autre accouplement thermique entre ledit
circuit de flux d'air (10) et ledit circuit de fluide frigorigène (30 ; 130 ; 230
; 330) le fluide frigorigène étant chauffé et ledit flux d'air (A) étant refroidi
;
- un compresseur (24) agencé dans ledit circuit de fluide frigorigène (30 ; 130 ;
230 ; 330) entre ledit second échangeur de chaleur (23) et ledit premier échangeur
de chaleur (21) ;
- un dispositif de dilatation de fluide frigorigène (22 ; 122) agencé dans ledit circuit
de fluide frigorigène (30 ; 130 ; 230 ; 330) entre ledit premier échangeur de chaleur
(21) et ledit second échangeur de chaleur (23) ;
caractérisé en ce que :
ledit procédé comprend l'étape consistant à confiner ledit fluide frigorigène dans
une ou plusieurs sections dudit circuit de fluide frigorigène (30 ; 130 ; 230 ; 330)
si une condition de travail anormale dudit circuit de fluide frigorigène (30 ; 130
; 230 ; 330) survient,
ladite condition de travail anormale étant une fuie de fluide frigorigène.
11. Procédé selon la revendication 10, caractérisé en ce que ladite étape de confinement dudit fluide frigorigène dans une ou plusieurs sections
dudit circuit de fluide frigorigène (30 ; 130 ; 230 ; 330) est réalisée en contrôlant
au moins deux dispositifs d'interruption (71, 72 ; 171, 172 ; 122) agencés le long
dudit circuit de fluide frigorigène (30 ; 130 ; 230 ; 330) de sorte que l'activation
ou la désactivation desdits dispositifs d'interruption (71, 72 ; 171, 172 ; 122) crée
ladite ou lesdites sections.
12. Procédé selon la revendication 10 ou 11, caractérisé en ce que ladite fuite de fluide frigorigène est détectée au moyen d'un capteur de fuite.
13. Procédé selon la revendication 10, 11 ou 12, caractérisé en ce que ladite fuite de fluide frigorigène est déterminée en analysant un ou plusieurs paramètres
de fonctionnement de ladite machine à laver le linge (1).
14. Procédé selon la revendication 13, caractérisé en ce que ledit ou lesdits paramètres de fonctionnement comprennent un des paramètres sélectionnés
dans un groupe comprenant : la température de flux d'air en amont et/ou en aval dudit
tambour (9), la température mesurée depuis une surface dudit premier échangeur de
chaleur (21) et la pression et/ou la température détectées ou calculées dudit fluide
frigorigène.
15. Procédé selon l'une quelconque des revendications précédentes 10 à 14, dans lequel
ladite fuite de fluide frigorigène survient quand :
un ou plusieurs paramètres de travail dudit compresseur (24) dépassent des seuils
de sécurité prédéterminés, et/ou
la température de fluide frigorigène et/ou la pression de fluide frigorigène dépassent
des seuils de sécurité prédéterminés.
16. Procédé selon la revendication 15, caractérisé en ce que lesdits paramètres de travail dudit compresseur comprennent le courant et/ou l'absorption
de puissance dudit compresseur (24).
17. Procédé selon l'une quelconque des revendications précédentes 10 à 16, caractérisé en ce qu'il comprend en outre l'étape consistant à émettre une alarme d'avertissement pour
l'utilisateur.
18. Procédé selon l'une quelconque des revendications précédentes 10 à 17, caractérisé en ce qu'il comprend en outre l'étape consistant à désactiver ledit compresseur si ladite condition
de travail anormale survient.