Clothes dryer

Abstract

The present disclosure provides a clothes dryer that suppresses ignition of a flammable refrigerant that leaks when refrigerant leakage is detected. The clothes dryer according to the present disclosure is provided with: a rotatable rotation tank that accommodates clothes; a circulation air passage that communicates with the rotation tank; an air blower that circulates air through the circulation air passage in the rotation tank; and a heat pump that is provided with a heat sink, a heat absorber, a compressor, and a pressure reduction unit. A refrigerant leak detection means for detecting the presence or absence of refrigerant leak in the heat pump, and a control means for controlling the operation of the blower and the heat pump, the heat sink heating the air in the circulation air path, the heat absorber cooling and dehumidifying the air in the circulation air path, and the compressor compressing the flammable refrigerant and supplying the flammable refrigerant to the heat sink, and a pressure reduction means for reducing the pressure of the flammable refrigerant passing through the radiator, and a control means for stopping the operation of the compressor and continuing the operation of the blower when the refrigerant leakage is detected by the refrigerant leakage detection means during the drying operation.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a laundry drying machine. BACKGROUND

[0002] As a means to achieve high efficiency of drying performance of a laundry drying machine, there is a method of mounting a heat pump device. In recent years, for a refrigerant used for the heat pump device, from the viewpoint of preventing global warming, a natural refrigerant, a hydrofluoroolefin (HFO) refrigerant, which has a smaller global warming potential, is required.

[0003] Patent Literature 1 discloses a laundry drying machine for which, even in the case of an unexpected leakage of a flammable refrigerant such as a natural refrigerant, there is no concern that static electricity generated during drying of laundry becomes an ignition source, and the safety is high. For the laundry drying machine, in the case where it is detected that there is no refrigerant leakage, when a drying rate becomes a first predetermined value that is greater than 100%, the operation of a blower and a heat pump is stopped, and in the case where it is detected that there is a refrigerant leakage, when the drying rate becomes a second predetermined value that is 100% or more and lower than the first predetermined value, the operation of the blower and the heat pump is stopped.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2013-226249 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The present disclosure provides a laundry drying machine for which, in the case where a refrigerant leakage is detected in a drying operation, even if a user with static electricity mistakenly puts a hand into a rotating tub in an attempt to take out laundry in the rotating tub, generation of a spark caused by the static electricity can be suppressed, and ignition of a flammable refrigerant can be suppressed.

[0009] SOLUTION TO PROBLEM

[0010] The clothes dryer disclosed herein comprises: a rotating trough for storing and rotating clothes; a circulating air duct connected to the rotating trough; a blower for circulating air through the circulating air duct within the rotating trough; a heat pump comprising a radiator, a heat absorber, a compressor, and a pressure reducing unit, wherein the radiator heats the air in the circulating air duct, the heat absorber cools and dehumidifies the air in the circulating air duct, the compressor compresses a flammable refrigerant and supplies it to the radiator, and the pressure reducing unit reduces the pressure of the flammable refrigerant passing through the radiator; a refrigerant leak detection unit for detecting the presence or absence of refrigerant leakage in the heat pump; and a control unit for controlling the operation of the blower and the heat pump. For the control unit, when a refrigerant leak is detected by the refrigerant leak detection unit during drying operation, the compressor is stopped, while the blower continues to operate.

[0011] The effects of the invention

[0012] The clothes dryer disclosed herein stops the compressor when a refrigerant leak is detected, while the blower continues to run. This causes the condensate on the absorber to evaporate, creating high-humidity circulating air that returns to the rotating drum. As a result, the humidity inside the rotating drum increases, so even if a user with static electricity puts their hand into the drum, they are only discharging moisture into the air inside. Therefore, since sparks can be suppressed within the rotating drum, the possibility of ignition is suppressed even if the leaking refrigerant is in a flammable area. Attached Figure Description

[0013] Figure 1 This is a longitudinal sectional view of the drum-type washer-dryer in Embodiment 1.

[0014] Figure 2 This is a system architecture diagram of the drum-type washer-dryer in Implementation Method 1.

[0015] Figure 3 This is a block diagram of the drum-type washer-dryer in Embodiment 1.

[0016] Figure 4 This is a flowchart of the drying operation of the drum-type washer-dryer in Implementation Method 1.

[0017] Explanation of reference numerals in the attached figures

[0018] 1. Water tank; 1a. Front surface opening; 2. Housing; 3. Suspension mechanism; 4. Rotating drum (rotating trough); 4a. Inlet; 4b. Hole; 5. Rotating shaft; 6. Lifting rib; 7. Motor; 8. Cover; 9. Seal; 10. Washing water heater; 11. Water supply valve; 12. Drain valve; 13. Drainage path; 15. Water temperature detection unit; 16. Water level detection unit; 17. Circulating air outlet; 18. Circulating air inlet; 19. Air duct (circulating air duct); 20. Filter; 21. Blower; 22. Heat absorber; 23. Radiator; 24. Piping; 2 4a. Discharge port; 24b. Suction port; 25. Compressor; 27. Space; 28. Water storage section; 31. Refrigerant leak detector (refrigerant leak detection unit); 32a. First refrigerant temperature detection unit; 32b. Second refrigerant temperature detection unit; 33. First temperature detection unit; 34. Second temperature detection unit; 35. Control unit; 36. Operation display unit; 37. Fabric quantity detection unit; 38. Humidity detection unit; 39. Notification unit; 41. Heat pump unit; 42. Pressure reducing unit; 43. Heat pump housing; 100. Drum washer-dryer. Detailed Implementation

[0019] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, there are instances where unnecessary details are omitted. For example, detailed descriptions of already well-known matters or repetitive descriptions of substantially the same structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art.

[0020] Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure, and are not intended to limit the subject matter of the claims by means of the drawings and the following description.

[0021] (Implementation Method 1)

[0022] The following uses Figures 1-4 Description of Implementation Method 1.

[0023] [1-1. Structure]

[0024] [1-1-1. Structure of a drum-type washer-dryer]

[0025] In this embodiment, the clothes drying mechanism is a drum-type washer-dryer 100. Figure 1 This is a longitudinal sectional view of a drum-type washer-dryer 100, which is a clothes dryer in Embodiment 1. Figure 2 This is the system architecture diagram of the drum washer-dryer 100. Figure 3 This is a block diagram of a drum washer-dryer 100.

[0026] existFigure 1 , Figure 2 In this design, the water tank 1 is elastically supported within the housing 2 by multiple suspension mechanisms 3. The rotating drum 4 has an inlet 4a on its front side for taking out and putting in laundry such as clothes Z, and is configured as a bottomed cylindrical shape and disposed within the water tank 1. The rotating drum (rotating tank) 4 is rotatable about a rotating shaft 5 and can hold laundry such as clothes Z.

[0027] A large number of holes 4b are provided around the circumference of the rotating drum 4, and lifting ribs 6 are provided at multiple locations on the inner side of the rotating drum 4 for lifting the laundry along the rotation direction of the rotating drum 4. The water tank 1, the rotating drum 4 and the rotating shaft 5 are arranged at a predetermined angle (e.g., 10° to 20°) forward and upward relative to the horizontal.

[0028] An electric motor 7 is provided on the outer side of the rear surface of the water tank 1 to drive the rotating drum 4 to rotate in both directions. The electric motor 7 is composed of a brushless DC motor or the like, and its rotation speed can be freely changed by controlling it with an inverter.

[0029] A cover 8 is provided on the front surface of the housing 2 to open and close the inlet 4a. The opening 1a on the front surface of the water tank 1, which is opposite to the inlet 4a of the rotating drum 4, is sealed to the housing 2 by a flexible, telescopic seal 9. The cover 8 is provided with a transparent window so that the interior of the rotating drum 4 can be observed from the outside.

[0030] When the cover 8 is closed, the sealing element 9 located at the opening 1a on the front surface of the water tank 1 comes into contact with the inner surface of the cover 8, and the water tank 1 becomes a watertight and airtight space, so that water and air do not leak to the outside during the washing, rinsing, dehydration and drying processes.

[0031] A water supply valve 11 is provided inside the housing 2 to control the supply of tap water to the water tank 1. The water supply valve 11 is connected to a water supply path (not shown) that communicates with the water tank 1 via a detergent dispenser (not shown). The water supply path is connected to a tap water pipe, and the supply and stop of tap water to the water tank 1 can be controlled by opening and closing the water supply valve 11.

[0032] Additionally, a drain valve 12 is provided at the lower rear of the sink 1 to drain the washing water from the sink 1. By opening and closing the drain valve 12, the washing water in the sink 1 can be drained and the draining can be stopped via the drain path 13.

[0033] A washing water heater 10 for heating washing water is provided at the rear of the bottom inside the water tank 1. The washing water heater 10 is formed by bending a sheath heater in a roughly U-shape and is installed along the bottom surface of the water tank 1 in a direction extending toward the rotation axis.

[0034] A space is provided between the washing water heater 10 and the bottom surface of the water tank 1. When washing water accumulates in the water tank 1, the washing water heater 10 is located below the water surface, immersed in the washing water, and heats the washing water. The temperature of the washing water heated by the washing water heater 10 is detected by a water temperature detection unit 15, which is composed of a thermistor or the like, installed at the bottom of the water tank 1.

[0035] The amount of washing water accumulated in the water tank 1 is detected by the water level detection unit 16. The water level detection unit 16 is composed of a pressure sensor and the like, which has a diaphragm inside and detects the pressure based on the amount of deformation of the diaphragm when pressure is applied, and detects the water level of the washing water supplied to the water tank 1.

[0036] A circulating air outlet 17 is provided on the peripheral side wall at the upper front part of the water tank 1, and a circulating air inlet 18 is provided on the rear part of the water tank 1. The circulating air outlet 17 and the circulating air inlet 18 are connected by an air passage (circulating air passage) 19 extending from the front surface side to the rear surface side above the exterior of the water tank 1.

[0037] [1-1-2. Structure of a Heat Pump Unit]

[0038] like Figure 1 , Figure 2 As shown, the absorber 22 and the radiator 23 are connected to the compressor 25 through the pipe 24 through which the refrigerant flows.

[0039] For the heat pump device 41, a flammable refrigerant (e.g., R600a, R290) or a weakly flammable refrigerant (e.g., R1234yf) is used as the refrigerant. The compressor 25, radiator 23, pressure reducing unit 42 and heat absorber 22 are connected by a pipeline 24 to allow the refrigerant to circulate. The compressor 25 compresses the refrigerant, the radiator 23 dissipates the heat of the compressed high-temperature and high-pressure refrigerant, and the pressure reducing unit 42 is composed of a capillary tube or expansion valve for reducing the pressure of the high-pressure refrigerant. In the heat absorber 22, the refrigerant, which has been reduced to low pressure, absorbs heat from the surroundings.

[0040] At least the heat absorber 22 and the heat radiator 23 are housed in the heat pump housing 43, and the heat absorber 22 and the heat radiator 23 are assembled in the air duct 19 so that dry air can pass through.

[0041] The absorber 22 and the radiator 23 are composed of finned tube heat exchangers. The ends of the absorber 22 and the radiator 23 are connected by end plates, and a space 27 is provided between the absorber 22 and the radiator 23.

[0042] The refrigerant flow path 24 is formed, for example, by a copper tube, and is constructed by passing through multiple fins arranged in parallel at predetermined intervals to form a flow path for dry air. The fins are formed, for example, by a stamped aluminum plate with a thickness of 0.08 mm to 0.2 mm, and the fin spacing is configured, for example, to be about 1.2 mm.

[0043] The compressor 25 is driven by a compressor motor (not shown). The refrigerant is pressurized by the compression mechanism to become a high-temperature and high-pressure gaseous refrigerant, which is discharged from the outlet 24a of the pipeline 24 and delivered to the radiator 23.

[0044] In radiator 23, the high-temperature, high-pressure gaseous refrigerant is cooled and condensed by the dry air delivered from blower 21 to air passage 19, becoming a low-temperature, high-pressure liquid refrigerant. This liquid refrigerant is depressurized by pressure reducing unit 42 and then transported to absorber 22. In absorber 22, the liquid refrigerant is heated and evaporated by the high-temperature, humid air inside rotating drum 4 that is in contact with laundry such as clothes Z, becoming a low-temperature, low-pressure gaseous refrigerant. This low-temperature, low-pressure gaseous refrigerant is then drawn into compressor 25 from suction port 24b of pipe 24 and pressurized.

[0045] A crankcase heater (not shown) is provided at the lower part of the compressor 25 to heat the compressor 25. The crankcase heater is mounted around the compressor 25. Alternatively, the crankcase heater may be mounted in a manner that heats the compressor 25 from top to bottom in order to rapidly raise the temperature of the compressor 25.

[0046] Figure 2 Arrow A indicates the flow direction of the drying air flowing in air passage 19, and arrow B indicates the flow direction of the refrigerant flowing in pipe 24.

[0047] A first refrigerant temperature detection unit (refrigerant temperature detection unit) 32a is provided in the pipe 24 between the compressor 25 and the radiator 23. The first refrigerant temperature detection unit 32a is composed of a thermistor, etc., and detects the temperature of the refrigerant discharged from the compressor 25.

[0048] A second refrigerant temperature detection unit (refrigerant temperature detection unit) 32b is provided in the refrigerant condensation section between the refrigerant inlet and outlet of the radiator 23. The second refrigerant temperature detection unit 32b is composed of a thermistor or the like, and detects the temperature of the refrigerant between the inlet where the refrigerant flows into the radiator 23 and the outlet where the refrigerant flows out of the radiator 23.

[0049] A first temperature detection unit 33 and a second temperature detection unit 34 are provided to detect the temperature of the drying air flowing in the air passage 19. The first temperature detection unit 33, composed of a thermistor or the like, detects the temperature of the drying air flowing into the rotating drum 4 from the circulating air inlet 18. The second temperature detection unit 34, composed of a thermistor or the like, detects the temperature of the drying air flowing out of the rotating drum 4 from the circulating air outlet 17. Based on the outputs of the first temperature detection unit 33 and the second temperature detection unit 34, the drying status of the laundry (such as clothes Z) inside the rotating drum 4 is detected.

[0050] The refrigerant leak detector 31 (refrigerant leak detection unit) is installed in the air passage 19 on the downstream side of the blower 21 to detect refrigerant leaks.

[0051] A humidity detection unit 38 is located at the circulating air outlet 17 to detect the humidity of the air flowing in from the rotating drum 4. The humidity detection unit 38 uses a capacitive humidity sensor or a resistive humidity sensor, but a capacitive humidity sensor offers better accuracy and is preferred. Furthermore, when detecting the drying status of laundry items such as clothes Z inside the rotating drum 4 based on the outputs of the first temperature detection unit 33 and the second temperature detection unit 34, as well as the output of the humidity detection unit 38, higher accuracy can be achieved.

[0052] Additionally, the control unit 35 (see reference) controls the washing and drying operations. Figure 3 The operation display unit 36 ​​is mounted on the upper part of the front surface inside the housing 2. The operation display unit 36 ​​includes an operation section (not shown) for manual operation and a display section (not shown) for displaying settings and operating status.

[0053] [1-2. Actions]

[0054] Regarding the washer-dryer configured as described above, its operation and function are explained below. The washing operation is performed in the order of washing, intermediate dehydration, rinsing, and dehydration, and the drying operation can be performed after the dehydration process.

[0055] During washing, open the cover 8, put clothes Z and other laundry into the rotating drum 4, and turn on the power switch on the operation display unit 36 ​​located on the upper part of the front surface of the housing 2. By using various setting buttons to input the selection of the operation program, input the time of each process as needed, and start the operation, the control unit 35 can execute a series of actions from washing to drying based on the settings.

[0056] First, in the washing process, the fabric quantity detection unit 37 (refer to...) is used. Figure 3The amount of laundry (such as clothes Z) placed into the rotating drum 4 is detected. The fabric weight detection unit 37 can detect the fabric weight based on factors such as the current value of the motor 7 that rotates the rotating drum 4. The water supply valve 11 is opened, and a preset amount of water is supplied according to the amount of laundry detected by the fabric weight detection unit 37. The water level detection unit 16 detects the water level in the water tank 1, and when the preset amount of water is supplied, the water supply valve 11 is closed.

[0057] When water and detergent are supplied to the tank 1 through the water supply path, the rotating drum 4 is driven by the motor 7 to rotate, starting the washing process (stirring step) based on the stirring action. The rotating drum 4 is rotated at a predetermined speed (e.g., 50 r / min), and the clothes Z and other laundry items are lifted along the rotation direction of the rotating drum 4 by the lifting ribs 6 provided on the inner circumferential surface of the rotating drum 4, and the clothes Z and other laundry items are dropped from the top inside the rotating drum 4, thereby performing a washing process based on tumbling for a predetermined time.

[0058] After the agitation process, the drain valve 12 is opened to drain the washing water from the tank 1, and the following intermediate dehydration process is performed: the rotating drum 4 is rotated at high speed (e.g., 900 r / min) to dehydrate the stains, detergent, etc. contained in the laundry Z along with the water. Next, the water supply valve is opened to supply a set amount of fresh water to the tank 1, and the rotating drum 4 is rotated at a predetermined speed (e.g., 50 r / min) for a predetermined rinsing process.

[0059] After the rinsing process has been performed a predetermined number of times for a predetermined time, the washing water in the water tank 1 is drained, and the following dehydration process is performed: the rotating drum 4 is rotated at high speed (e.g., 1500 r / min) to dehydrate the water and residual detergent components contained in the laundry, and the washing process is completed.

[0060] During the subsequent washing and drying cycle, the process transitions to the drying cycle after the dehydration cycle. In the drying cycle, the rotating drum 4 is rotated at a predetermined speed (e.g., 50 r / min) to agitate the laundry inside the drum 4. The blower 21 and heat pump unit 41 are activated to begin circulating drying air into the rotating drum 4 and to compress refrigerant based on the compressor 25.

[0061] In the heat pump unit 41, the compressor motor (not shown) of the compressor 25 drives the refrigerant, which is then compressed and discharged from the compressor 25 under this pressure. The refrigerant discharged from the compressor 25 flows in the pipe 24 and circulates in the radiator 23, the pressure reducing unit 42, the absorber 22, and the compressor 25. The heat of the compressed refrigerant is dissipated through the inflow into the radiator 23 to the air in contact with the fins of the pipe 24 disposed within the radiator 23, thus heating the dry air flowing in the air passage 19.

[0062] The heated drying air is supplied into the rotating drum 4 through the self-circulating air inlet 18, absorbs moisture from the laundry to become humid air, and is discharged into the air passage 19 through the self-circulating air outlet 17. As the laundry dries, lint and other fibers are generated from the laundry. The drying air discharged from the self-circulating air outlet 17 passes through the filter 20, which captures the lint contained in the air.

[0063] The lint-free drying air, filtered by filter 20, flows through absorber 22 through which refrigerant, reduced to low pressure by pressure reducing unit 42, absorbs sensible and latent heat, thus dehumidifying the air. The condensed water generated by dehumidification drips into water storage section 28, and the dehumidified and dried air is heated by radiator 23. The condensed water formed by dehumidification flows down the back of water tank 1 from water storage section 28 and is discharged outside the unit through drain valve 12.

[0064] During the drying process, the temperature of the drying air flowing in the air passage 19 is detected using a first temperature detection unit 33 and a second temperature detection unit 34. The temperature of the drying air flowing into the rotating drum 4 is detected by the first temperature detection unit 33, and the temperature of the drying air flowing out of the rotating drum 4 is detected by the second temperature detection unit 34. Based on the output of the temperature detection units, the dryness of the laundry inside the rotating drum 4 is detected, and the drying process ends when a predetermined dryness level is detected.

[0065] On the other hand, in the heat pump device 41, the heat of the high-temperature and high-pressure gaseous refrigerant compressed and vaporized by the compressor 25 is absorbed by the drying air passing through the radiator 23 and condensed. The pressure is reduced by the pressure reducing unit 42 to become a low-temperature and low-pressure liquid refrigerant, and it absorbs heat from the drying air by the heat absorber 22 to vaporize, becoming a low-temperature and low-pressure gaseous refrigerant and returning to the compressor 25.

[0066] The compressor motor drive is controlled in such a way that the temperature of the refrigerant (refrigerant condensation temperature) detected by the second refrigerant temperature detection unit 32b is maintained within a predetermined temperature range (e.g., 60°C to 70°C), so that the operation of the compressor 25 is stable and a safe and stable heat pump cycle is achieved.

[0067] In addition, in order to ensure the insulation of the compressor motor, the compressor motor is controlled to drive in such a way that the temperature of the refrigerant discharged from the compressor 25, as detected by the first refrigerant temperature detection unit 32a, is below a predetermined temperature (e.g., 100°C).

[0068] Figure 4 This is a flowchart of the drying operation of a drum washer-dryer 100. (Usage) Figure 4 The flowchart of the drying operation illustrates the response to a refrigerant leak.

[0069] If a refrigerant leaks during the aforementioned drying operation (step S001) and the refrigerant leak detector 31 detects the refrigerant (step S002, yes), then the compressor 25 is stopped (step S003), while the rotation of the rotating drum 4 and the operation of the blower 21 continue. If the humidity detected by the humidity detection unit 38 reaches a predetermined humidity RH or higher, for example, 55% to 80% or higher (step S004, yes), then the rotation of the rotating drum 4 is stopped (step S005), and the blower 21 is stopped (step S006). Afterwards, the notification unit 39 (see...) Figure 3 Issue an exception notification (step S007).

[0070] [1-3. Effects, etc.]

[0071] As described above, in this embodiment, the drum-type washer-dryer 100 includes: a rotating drum 4 that holds clothes and is capable of rotation; an air duct 19 connected to the rotating drum 4; a blower 21 that circulates air through the air duct 19 within the rotating drum 4; and a heat pump unit 41 comprising a radiator 23, a heat absorber 22, a compressor 25, and a pressure reducing unit 42. The radiator 23 heats the air within the air duct 19, the heat absorber 22 cools and dehumidifies the air within the air duct 19, and the compressor 25... The compressor 25 compresses the flammable refrigerant and supplies it to the radiator 23. The pressure reducing unit 42 reduces the pressure of the flammable refrigerant passing through the radiator 23. The refrigerant leak detector 31 detects whether there is a refrigerant leak in the heat pump device 41. The control unit 35 controls the operation of the blower 21 and the heat pump device 41. When the refrigerant leak detector 31 detects a refrigerant leak during drying operation, the control unit 35 stops the operation of the compressor 25 and keeps the blower 21 running.

[0072] Therefore, the condensation that forms and is retained in the absorber 22 during the drying operation, as well as the moisture from the still damp laundry such as clothes Z, is evaporated by airflow, and the rotating drum 4 and air duct 19 are humidified. Thus, even if static electricity is generated from the friction of the laundry such as clothes Z, or if a user with static electricity accidentally puts their hand into the rotating drum 4, the static electricity is discharged into the moisture in the air, thereby suppressing the spark that could ignite the leaking refrigerant and preventing its ignition.

[0073] As in this embodiment, it can also be configured such that, in the drum washer-dryer 100, when the refrigerant leak detector 31 detects a refrigerant leak, the compressor 25 is stopped, the rotating drum 4 is stopped, and the blower 21 is started.

[0074] Therefore, it is possible to suppress the generation of static electricity based on friction from washing materials such as clothes. Consequently, it is possible to suppress sparks that could ignite leaking refrigerant, and thus suppress the ignition of leaking refrigerant.

[0075] As in this embodiment, the drum washer-dryer 100 may also include: a humidity detection unit 38 that detects the humidity in the air duct 19 or the rotating drum 4; and a notification unit 39 that notifies of an abnormality when the refrigerant leak detector 31 detects a leak. For the control unit 35, the refrigerant leak detector 31 detects a refrigerant leak, causing the compressor 25 to stop operating, and when the humidity detected by the humidity detection unit 38 reaches or exceeds a predetermined humidity level, the blower 21 is stopped, and then the notification unit 39 issues an abnormality notification.

[0076] Therefore, even if a user with static electricity hears the above notification and frantically tries to remove their clothes, sparks can be suppressed even if they put their hand inside the rotating drum 4. Thus, the clothes can be safely removed.

[0077] (Other implementation methods)

[0078] As illustrated above, Embodiment 1 has been described as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this and can be applied to embodiments with modifications, substitutions, additions, omissions, etc. Furthermore, new embodiments can be created by combining the constituent elements described in Embodiment 1 above.

[0079] Therefore, other implementation methods are illustrated below.

[0080] In Embodiment 1, as an example of the installation of the humidity detection unit 38, the case where it is installed at the circulating air outlet 17 is described. Regarding the humidity detection unit 38, it is sufficient to detect the humidity inside the rotating drum 4, and it is sufficient that the humidity inside the rotating drum 4 is greater than a predetermined value. Therefore, the location of the humidity detection unit 38 is not limited to the circulating air outlet 17.

[0081] Therefore, the humidity detection unit 38 can achieve the same effect as long as it is installed in any of the water tank 1, the rotating drum 4, or the air duct 19.

[0082] Furthermore, in the event of a refrigerant leak, it is sufficient to maintain a high humidity level inside the rotating drum 4. Therefore, if the relationship between the operating time of the blower 21 and the increase in humidity inside the rotating drum 4 is experimentally determined beforehand, the same effect can be achieved by simply running the blower 21 for a period of time until the humidity reaches a predetermined concentration and then stopping it.

[0083] In Embodiment 1, as an example of a refrigerant leak detection unit, a structure was described that detects leaks by directly reacting with the refrigerant through a refrigerant leak detector 31. However, refrigerant leaks can also be detected based on the operating status of the heat pump unit 41. For example, the control unit 35 can function as a refrigerant leak detection unit, which uses the refrigerant temperature detected by a first refrigerant temperature detection unit 32a or a second refrigerant temperature detection unit 32b provided for controlling the compressor 25, etc., and detects the occurrence of refrigerant leaks based on abnormal changes in the refrigerant temperature.

[0084] In this case, the location where the first refrigerant temperature detection unit 32a or the second refrigerant temperature detection unit 32b is installed on the pipeline 24 to detect the refrigerant temperature is the high-pressure side. When refrigerant leaks and the refrigerant in the heat pump unit 41 decreases, the discharge temperature of the compressor 25 tends to rise. Meanwhile, the discharge pressure tends to decrease, and the condensing temperature of the radiator 23 does not rise to the predetermined temperature. Therefore, by comparing the predetermined refrigerant temperature under normal operating conditions with the refrigerant temperature under operating conditions with less refrigerant and understanding their changing trends, the occurrence of refrigerant leakage can be detected. By including the refrigerant leak detector 31 in the control unit 35, which utilizes both the first refrigerant temperature detection unit 32a and the second refrigerant temperature detection unit 32b, a refrigerant leak detection unit can be constructed cost-effectively.

[0085] Furthermore, the location for detecting the refrigerant temperature in pipe 24 is not limited to the high-pressure side. It can also be located on the low-pressure side, for example, near the suction inlet 24b of compressor 25. Alternatively, it can be located at a location capable of detecting the evaporation temperature of absorber 22. Even at the aforementioned locations, refrigerant leaks can be detected by pre-knowing the predetermined refrigerant temperature based on the operating conditions and the trend of refrigerant leakage.

[0086] Furthermore, the refrigerant temperature detected by the refrigerant temperature detection units 32a and 32b gradually changes along with the drying state of the clothes in the rotating tray 4. Therefore, for the control unit 35, by coordinating the detection of the temperature of the drying air detected by the first temperature detection unit 33 and the temperature of the drying air detected by the second temperature detection unit 34 located in the air passage 19, the detection of refrigerant leakage can be performed with higher accuracy.

[0087] Furthermore, in the case of a very small, slow refrigerant leak, there is a possibility that the refrigerant temperature may not change significantly in the initial stage. In this case, since the amount of the leaking flammable refrigerant is small, the possibility of ignition is low. Considering this situation, it is more preferable to use both the unit that indirectly detects refrigerant leaks and the refrigerant leak detector 31 that directly detects refrigerant leaks, thereby constructing a dual refrigerant leak detection unit.

[0088] Industrial availability

[0089] This disclosure can be applied to heat pump dryers that use flammable or weakly flammable refrigerants. Specifically, this disclosure can be applied to vertical washer-dryers, drum washer-dryers, bathroom dryers, etc.

Claims

1. A clothes dryer, wherein, This clothes dryer features: A rotating tray that holds clothes and can rotate; A circulating air path, which is connected to the rotating slot; A blower that circulates air through the circulating air path within the rotating slot; A heat pump includes a radiator, a heat absorber, a compressor, and a pressure reducing unit. The radiator heats the air in the circulating air path, the heat absorber cools and dehumidifies the air in the circulating air path, the compressor compresses a flammable refrigerant and supplies it to the radiator, and the pressure reducing unit reduces the pressure of the flammable refrigerant passing through the radiator. A refrigerant leak detection unit detects whether or not the heat pump is leaking refrigerant. as well as The control unit controls the operation of the blower and the heat pump. For the control unit, when a refrigerant leak is detected by the refrigerant leak detection unit during drying operation, the compressor operation is stopped, and Keep the blower running.

2. The clothes dryer according to claim 1, wherein, For the control unit, when a refrigerant leak is detected by the refrigerant leak detection unit... The compressor is stopped from operating, and then the rotation of the rotating slot is stopped. To make the blower run.

3. The clothes dryer according to claim 1 or 2, wherein, The clothes dryer includes: a humidity detection unit for detecting the humidity in the circulating air path or the rotating trough; and a notification unit for notifying the abnormality when the refrigerant leak detection unit detects a leak. For the control unit, when the refrigerant leak detection unit detects a refrigerant leak and stops the compressor, and the humidity detected by the humidity detection unit reaches a predetermined humidity level, the blower is stopped, and then the notification unit issues an abnormality notification.

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