JP6486197B2 - Clothes dryer - Google Patents

Description

  The present embodiment relates to a clothes dryer.

  2. Description of the Related Art Conventionally, clothes dryers equipped with a heat pump for drying clothes such as laundry have attracted attention because they have better drying efficiency and energy saving effects than those equipped with heaters for heating. In a clothes dryer equipped with a heat pump, a circulation air passage communicating with a drying chamber for storing clothes is provided, and a circulation fan for circulating the air in the drying chamber and an evaporator and a condenser constituting a part of the heat pump are circulated. It is arranged in the air passage.

  The heat pump includes a compressor that compresses and discharges the refrigerant, a condenser that dissipates and liquefies the high-temperature and high-pressure gas refrigerant discharged from the compressor, a decompression device that decompresses the refrigerant that has passed through the condenser, An evaporator that vaporizes the liquefied refrigerant is sequentially connected by piping, and the refrigerant is circulated by driving the compressor.

  Then, the air in the circulation air passage is heated by the heat released from the condenser and then sent into the drying chamber, and the air deprived of moisture is dehumidified by cooling in the evaporator in the circulation air passage. The clothes are dried by repeatedly heating the air again with a condenser and supplying the air to the drying chamber.

  In this type of clothes dryer, the compressor constituting the heat pump is driven by inverter control to reduce the number of revolutions, and the refrigerant discharge temperature and pressure are lowered to reduce the operating load factor and improve the energy saving performance. However, when using a constant speed compressor that can be driven at a constant speed and the rotation speed cannot be changed, it is difficult to reduce the operating load factor for continuous operation and to improve energy saving performance. There's a problem.

JP 2014-204883 A

  The present invention has been made in consideration of the above-described problems, and is a garment that can improve energy-saving performance even when a constant speed compressor that can be driven at a constant speed and cannot change the rotation speed is used as a compressor. The purpose is to provide a dryer.

  The clothes dryer according to the present embodiment includes a drying chamber having an exhaust port and an air supply port, a circulation air path provided outside the drying chamber and connecting the exhaust port and the air supply port, and through the circulation air channel. A circulation fan that circulates the air in the drying chamber, a condenser that heats the air in the circulation air path, an evaporator that cools and dehumidifies the air in the circulation air path, and a refrigerant that is compressed into the condenser A heat pump including a compressor to be supplied, and a decompression unit that decompresses the refrigerant that has passed through the condenser; an inlet temperature sensor that detects a temperature of air supplied from the circulation air passage to the drying chamber; An exhaust port temperature sensor for detecting the temperature of air exhausted from the drying chamber to the circulation air passage, a condenser temperature sensor for detecting the temperature of the condenser, and a control device for controlling the heat pump and the circulation fan. The control device comprises: The drying process in which the compressor and the circulation fan are driven to dry the clothes in the drying chamber, and the compressor is stopped when the temperature detected by the condenser temperature sensor becomes equal to or higher than a predetermined temperature during the drying process. A preheat drying process for driving the circulation fan is performed, and the preheat drying process is terminated when a difference between detected temperatures of the exhaust port temperature sensor and the air supply port temperature sensor becomes a predetermined temperature or less.

It is a perspective view from the front of the washing and drying machine concerning a 1st embodiment. It is sectional drawing which shows schematically the internal structure of a washing-drying machine. It is a perspective view from the back which shows the state except the outer case of the washing dryer. It is a schematic block diagram of a washing dryer. It is a block diagram which shows the electric constitution of a washing / drying machine. It is a flowchart of the drying process of a washing dryer. It is a schematic block diagram of the washing-drying machine of 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  The present embodiment relates to a drum-type washing and drying machine that serves as both a washing machine and a clothes dryer as shown in FIGS. 1 and 2, and is provided in a substantially rectangular box-like outer box 1 and a lower part thereof. An outer shell is formed from the base plate 2. A laundry entrance / exit 3 having a circular opening is formed in the front surface portion 1 a of the outer box 1, and the laundry entrance / exit 3 is opened and closed by a door 4 provided so as to be pivotable laterally via a hinge 5. . An operation display panel 6 is provided at a position above the laundry entrance 3 in the front face 1a, and a drawer-type detergent charging case 7 is provided on the side of the operation display panel 6. As shown in FIG. 5, the operation display panel 6 is connected to the control device 23 and displays various settings of the washing / drying machine such as selection of an operation course and an operation status in response to an operation from the user.

  As shown in FIG. 2, a substantially cylindrical water tank 8 having an open front surface and a closed rear surface is disposed in the outer box 1. The aquarium 8 is elastically supported on the base plate 2 in such a manner that the axial direction of the aquarium 8 is a horizontal axis in the front-rear direction and is slightly inclined rearward so that the front opening communicates with the laundry entrance 3. It is elastically supported via the mechanism 9.

  Water such as tap water is supplied from the outside of the water tank 8 through the water supply valve 18, the water supply case 71, and the water supply hose 72, and is provided at the bottom of the water tank 8. The water in the water tank 8 can be drained out of the machine through the drain valve 19 and the drain hose 74 from the drain port 73. The water tank 8 is provided with an exhaust port 10 and an air supply port 11 in addition to the front opening, the water supply port 70, and the drainage port 73.

  In the water tank 8, a cylindrical rotating tank 14 having an open front surface and a closed rear surface is rotatably disposed. The rotating tank 14 is disposed in the water tank 8 in a state where the axial direction is a horizontal axis in the front-rear direction and is slightly inclined downward. A large number of holes 15 through which water and air can be passed are formed in the peripheral wall of the rotary tank 14, and the inside of the rotary tank 14 communicates with the water tank 8 through the holes 15. A plurality of baffles 16 are provided on the inner peripheral wall of the rotating tub 14. The front opening of the rotating tub 14 is also communicated with the laundry entrance 3, and the rotating tub 14 accommodates clothes put in from the laundry entrance 3. The rotating tub 14 is rotationally driven by a motor 17 provided on the back surface of the water tub 8. The rotating tub 14 having such a configuration functions as a washing tub during a washing process, as a dehydrating tub during a dehydration process, and as a drying chamber for storing clothes during a drying process.

  As shown in FIGS. 2 to 4, a circulation air passage 20 is connected to the exhaust port 10 and the air supply port 11 provided in the water tank 8, and the water tank 8 (the rotation tank 14 is connected to the circulation air passage 20 through the circulation air passage 20. ) The air inside can be circulated. The circulation air passage 20 includes an exhaust duct 24 connected to the exhaust port 10 of the water tank 8, an air supply duct 28 connected to the air supply port 11 of the water tank 8, a lower end of the exhaust duct 24, and a lower end of the air supply duct 28. And a heat exchange duct 22 for connecting the two.

  The heat exchange duct 22 is placed on the base plate 2 positioned below the water tank 8, and the evaporator 31 is disposed therein, and the condenser 32 is separated from the evaporator 31 to the downstream side of the heat exchange duct 22. And a circulation fan 26 that circulates and supplies the air in the water tank 8 through the circulation air passage 20.

  The evaporator 31 and the condenser 32 are tube-shaped with fins in which a large number of heat transfer fins are arranged at a predetermined pitch on the refrigerant circulation pipe, and the air in the water tank 8 is shown in FIG. As shown by the arrows in FIG. 2 and FIG. 4, the air flows in the circulation air passage 20 and flows between the heat transfer fins of the evaporator 31 and the condenser 32.

  As shown in FIG. 4, the evaporator 31 and the condenser 32 are a heat pump together with a compressor 33 that compresses the refrigerant supplied to the condenser 32, a decompressor 34 that decompresses the refrigerant discharged from the condenser 32, and an accumulator 35. 30 is configured. In the heat pump 30, a compressor 33, a condenser 32, a decompression device 34, an evaporator 31, and an accumulator 35 are connected in an annular manner through a connection pipe, and a refrigerant is enclosed therein to constitute a refrigeration cycle. .

  The evaporator 31 and the condenser 32 are configured by, for example, a pipe having a large number of fins provided at minute intervals. By flowing the refrigerant through the pipe, heat between the air passing between the fins and the refrigerant is obtained. Exchange.

  The compressor 33 is a constant speed compressor that is driven at a constant frequency according to the frequency of the supplied AC power supply, for example, and is controlled to be driven and stopped by the control device 23, and pumps the refrigerant to the condenser 32 during driving. The accumulator 35 provided on the suction side 33 a of the compressor 33 suppresses pressure fluctuation of the refrigerant flowing into the compressor 33.

  The decompression device 34 decompresses the high-pressure liquid refrigerant discharged from the condenser 32 to make a low-pressure gas-liquid mixed state. In this example, the decompression device 34 includes a flow rate control valve that controls the opening and closing of the refrigerant flow path between the condenser 32 and the evaporator 31 and the throttle amount.

  The heat pump 30 includes a bypass 36, an on-off valve 37, and a check valve 38. The bypass circuit 36 is, for example, a metal pipe and bypasses the compressor 33 to connect the suction side 33a and the discharge side 33b of the compressor 33. The on-off valve 37 is composed of, for example, an electromagnetic valve, and is provided in the middle of the detour path 36 to open and close the detour path 36. The check valve 38 is provided between the evaporator 31 and the compressor 33 and prevents the refrigerant from flowing backward from the compressor 33 side to the evaporator 31.

  The opening / closing valve 37 provided in the decompression device 34 and the detour 36 is also controlled by the control device 23. Specifically, while the compressor 33 is being driven, the control device 23 closes the on-off valve 37 to shut off the bypass circuit 36 and restricts the pressure reducing device 34 to a predetermined throttle amount. To release. In this state, as indicated by an arrow B in FIG. 4, the refrigerant sealed in the heat pump 30 is compressed by the compressor 33 to become a high-temperature and high-pressure refrigerant, and the high-temperature and high-pressure refrigerant flows into the condenser 32 to generate heat. Heat is exchanged with air in the exchange duct 22. As a result, the air in the heat exchange duct 22 is heated, and the refrigerant is cooled and liquefied. The liquefied refrigerant is then decompressed through the decompression device 34 and then flows into the evaporator 31 and vaporizes, whereby the evaporator 31 cools the air in the heat exchange duct 22. The refrigerant that has passed through the evaporator 31 returns to the compressor 33 and is compressed again to become a high-temperature and high-pressure refrigerant.

  Further, while the compressor 33 is stopped, the control device 23 closes the decompression device 34 to close the refrigerant flow path between the condenser 32 and the evaporator 31 and opens the on-off valve 37 to open the compressor. The suction side 33 a and the discharge side 33 b of 33 communicate with each other via a bypass 36.

  Thereby, the high temperature / high pressure refrigerant in the condenser 32 can be prevented from flowing into the evaporator 31 in the low temperature / low pressure state. Further, the high-temperature and high-pressure refrigerant on the discharge side 33b of the compressor 33 passes through the bypass circuit 36 as shown by the arrow C in FIG. The pressure difference between the suction side 33a and the discharge side 33b of the compressor 33 is eliminated.

  That is, the decompression device 34 functions as a blocking means that blocks the movement of the refrigerant from the condenser 32 side to the evaporator 31 side while the compressor 33 is stopped, and the bypass circuit 36 and the on-off valve 37 are connected to the compressor 33. It functions as a pressure difference adjusting means for adjusting the pressure difference between the suction side 33a and the discharge side 33b of the compressor 33 during the stop.

  As shown in FIGS. 4 and 5, the washing and drying machine includes an air inlet temperature sensor 40, an exhaust outlet temperature sensor 41, a condenser temperature sensor 42, and an outside air temperature sensor 43, and each temperature sensor 40, 41, 42, 43 is connected to the control device 23.

  As shown in FIG. 4, the supply air temperature sensor 40 and the exhaust air temperature sensor 41 are provided in the circulation air passage 20 and detect the temperature of the air in the circulation air passage 20. Among these, the air inlet temperature sensor 40 is provided between the condenser 32 and the air inlet 11 and in the vicinity of the air inlet 11, passes through the air inlet duct 28, and the water tank 8 serving as a drying chamber and the rotation. The temperature of the air supplied into the tank 14, that is, the air heated by the condenser 32 and supplied into the drying chamber is detected. The exhaust port temperature sensor 41 is provided between the evaporator 31 and the exhaust port 10 and in the vicinity of the exhaust port 10, and is exhausted from the water tank 8 and the rotary tank 14 that are drying chambers and passes through the exhaust duct 24. Detect the temperature. The condenser temperature sensor 42 is provided in the condenser 32 and detects the temperature of the condenser 32. The outside air temperature sensor 43 is provided inside the outer box 1 and detects the temperature (outside air temperature) of the installation atmosphere of the washing / drying machine.

  The control device 23 includes, for example, a microcomputer and a memory, and is arranged inside the outer box 1 so as to function as control means for controlling the overall operation of the washing / drying machine.

  The control device 23 receives various operation signals from various operation switches of the operation display panel 6 and receives temperature detection signals from the temperature sensors 40, 41, and 42, and stores them in a memory in advance. Based on the program, the motor 17, the water supply valve 18, the drain valve 19, the circulation fan 26, the compressor 33, and the pressure reducing device 34 are controlled.

  Next, an example of the operation of the washing / drying machine having the above configuration will be described.

  First, a schematic operation of the washing / drying machine will be described. The operation button of the operation display panel 6 is operated by the user to set the course of operation, and then the washing and drying machine continues washing operation, drying operation, or both operations according to the set operation course. The washing / drying operation to be performed is executed. As one of them, when the execution of the washing and drying operation is started, the water supply valve 18 is opened to supply the water tank 8 and then the washing process for rotating the rotating tank 14 at a low speed and the drain valve 19 are set. After the water tank 8 is opened and the water in the water tank 8 is discharged, a dehydration process for rotating the rotating tank 14 at a high speed is sequentially performed, and then a drying operation is performed.

  In the drying operation, the heated air dehumidified by the evaporator 31 and the condenser 32 is rotated in the heat exchange duct 22 while rotating the rotating tub 14 containing the wet clothes after rinsing and rinsing in both forward and reverse directions. The operation of supplying into the tank 14 is performed. In the present embodiment, the user can select and execute the normal course and the energy saving course as the drying operation.

  The normal course is a course in which the control device 23 performs a drying process of driving the circulation fan 26 while driving the compressor 33 at a constant frequency. At that time, the control device 23 closes the open / close valve 37 to shut off the bypass circuit 36 and opens the pressure reducing device 34 in a state where the flow path is narrowed to a predetermined throttle amount.

  By such operations of the heat pump 30 and the circulation fan 26, in the drying process, the air that has entered the rotating tub 14 from the water tank 8 dries the clothes, so that moisture is contained, and the moist air is discharged into the exhaust port. After flowing into the heat exchange duct 22 of the circulation air passage 20 from 10, it is cooled and dehumidified by the evaporator 31, and then heated by the evaporator 31 to warm air. Then, the warm air is supplied into the water tank 8 from the air supply port 11 through the air supply duct 28 and further supplied into the rotating tank 14 from the hole 15 to take away moisture from the clothes and dry the clothes. Then, it circulates again from the exhaust port 10 through the exhaust duct 24 and into the heat exchange duct 22.

  In this example, when the normal course is executed, the drying process is continuously executed until a predetermined drying end condition is satisfied unless an abnormality of the heat pump 30 such as the temperature of the compressor 33 reaches a predetermined temperature or more is detected. . The end condition of the drying process is, for example, whether the drying process time set in advance by the weight of clothes accommodated in the rotary tank 14 or the user's operation has elapsed, or the supply air temperature sensor 40 and the exhaust port The determination can be made based on whether the temperature difference detected by the temperature sensor 41 has converged within a predetermined range.

  The energy-saving course includes a drying process similar to the execution of the normal course described above, a preheat drying process in which the circulation fan 26 is driven while the compressor 33 is stopped, and a standby process in which the compressor 33 and the circulation fan 26 are stopped. It is a course that is repeatedly executed, and is a course that executes a drying operation in which the operation rate of the compressor 33 is lowered and the power consumption is suppressed compared to the normal course.

  Specifically, the control device 23 first drives the compressor 33 at a constant frequency in step S1 as shown in FIG. 6, and the circulation fan 26 at a predetermined rotational speed F1 (for example, F1 = 4200 rpm). Drive to perform the drying process. At that time, the control device 23 closes the open / close valve 37 to shut off the bypass circuit 36 and opens the pressure reducing device 34 in a state where the flow path is narrowed to a predetermined throttle amount.

Next, the controller 23 determines whether or not the detected temperature Tc of the condenser 32 detected by the condenser temperature sensor 42 has reached or exceeded a first predetermined temperature tc ₁ (for example, tc ₁ = 50 ° C.) in step S2. Judge. If the detected temperature Tc of the condenser 32 is less than the first predetermined temperature tc ₁ , the circulation fan 26 is continuously rotated at the rotation speed F1 and the step S2 is continued. If the detected temperature Tc is equal to or higher than the first predetermined temperature tc ₁ , the circulation fan. 26 is decelerated from F1 to F2 (for example, F2 = 4000 rpm) (step S3).

After the rotational speed of the circulation fan 26 is decelerated to F2, the control device 23 determines that the detected temperature Tc of the condenser 32 detected by the condenser temperature sensor 42 is the second predetermined temperature tc ₂ (for example, tc ₂₎ in step S4. = 55 ° C.) or higher. If the detected temperature Tc of the condenser 32 is lower than the second predetermined temperature tc ₂ , the circulation fan 26 is continuously rotated at the rotation speed F1 to continue this step S4, and if it is equal to or higher than the second predetermined temperature tc ₂ , the step S5 is performed. Proceed to

  In step S <b> 5, the control device 23 stops the compressor 33 while continuing to drive the circulation fan 26, thereby ending the drying process and executing the preheat drying process. In this example, the control device 23 decelerates the rotational speed of the circulation fan 26 from F2 to F3 (for example, F3 = 3000 rpm) in the remaining heat drying process, and further opens the on-off valve 37 to suck the compressor 33 33a and the discharge side 33b communicate with each other via the bypass circuit 36, and the decompression device 34 is closed to close the refrigerant flow path between the condenser 32 and the evaporator 31.

  When switching from the drying process to the preheat drying process in this way, the refrigerant circulating in the heat pump 30 during the drying process remains in the condenser 32 and the evaporator 31 in the preheat drying process, and the compressor 33 is Even after stopping, the condenser 32 is heated to a high temperature, and the evaporator 31 is cooled to a low temperature. Therefore, in the remaining heat drying process, the circulation fan 26 is rotated in a state where the compressor 33 is stopped, so that the heat and cold energy remaining in the condenser 32 and the evaporator 31 are utilized and the water tank 8 through the exhaust duct 24. The air flowing into the heat exchange duct 22 is dehumidified by the evaporator 31 and heated by the condenser 32 and then supplied to the water tank 8 through the air supply duct 28 to dry the clothes.

In step S6, the control device 23 detects the temperature of the air heated in the condenser 32 and supplied into the water tank 8 with the air inlet temperature sensor 40 during the remaining heat drying process. The temperature of the air that has been exhausted and passes through the exhaust duct 24 is detected by the exhaust port temperature sensor 41, and the temperature difference magnitude ΔT detected by the air supply port temperature sensor 40 and the exhaust port temperature sensor 41 is predetermined. If the value is within the value t _th , the process proceeds to step S7, where the process proceeds to a standby process and a drying process, which will be described later, or the preheating drying process is ended by terminating the drying operation.

  Specifically, in step S7, the control device 23 determines whether or not the operation rate W is equal to or less than a preset reference value α.

Here, the operation rate W is a ratio of the time during which the compressor 33 operates in the execution time of the energy saving course, and in this example, the control device 23 starts the drying process executed immediately before the preheat drying process. From the time (w _t1 / w _t ) of the execution time (time from step S1 to step S4) w _t1 of the drying process executed immediately before the time from the time to the present time (time from step S1 to step S7) w _t This operating rate W is calculated.

Further, the control device 23 calculates the operating rate W, and based on a control table (not shown) stored in the control device 23 in advance from the room temperature of the washing / drying machine installation atmosphere and the weight of the clothes in the rotary tub 14. α is determined. The reference value α can be arbitrarily set. As an example, a variable capacity compressor capable of changing the operating frequency by inverter control is incorporated in the heat pump 30 to set the temperature of the condenser 32 to the second predetermined temperature tc. _{2 The} reference value α can be set with reference to the operating frequency of the compressor when kept constant. In other words, if the operating frequency necessary to maintain the temperature of the condenser 32 at the second predetermined temperature tc ₂ using the variable capacity compressor having the excluded volume V ₀ is the frequency H ₀ , the operation is performed at the excluded volume V ₁ . When the constant speed compressor 33 having the frequency H ₁ is mounted on the heat pump 30, the reference value α can be set from the following equation.
Reference value α = (V ₀ × H ₀ ) / (V ₁ × H ₁ )

  Then, if the calculated operation rate W is larger than the reference value α (No in step S7), the control device 23 stops the residual heat drying process by stopping the circulation fan 26 and stops the compressor 33 and the circulation fan 26. The process proceeds to the waiting process (step S8). Then, the control device 23 continues the standby stroke until the operation rate W reaches the reference value α or less.

  On the other hand, if the operation rate W is equal to or less than the reference value α (Yes in Step S7), the process proceeds to Step S9 to determine whether or not a predetermined drying end condition is satisfied, and if not satisfied, the process returns to the drying step in Step S1, The drying process (steps S1 to S4), the preheat drying process (steps S5 to S6), and the stop process (steps S7 to S8) are repeatedly executed until a predetermined drying end condition is satisfied, and the predetermined drying is completed. If the condition is satisfied, the drying operation is terminated.

As described above, in the present embodiment, such as, when the detected temperature Tc of the condenser temperature sensor 42 detected by the condenser 32 during the drying cycle is in the second predetermined temperature tc ₂ or more, the power consumption by stopping the compressor 33 By driving the circulation fan 26 while suppressing, the clothes stored in the rotating tub 14 can be dried using the heat remaining in the evaporator 31 and the condenser 32, and the power consumption can be suppressed. .

  Moreover, in this embodiment, since the condenser 32 does not become higher than the second predetermined temperature tc, the air supplied to the rotating tub 14 is not excessively heated, and the clothes are placed at a relatively low temperature. It can be dried to reduce damage caused by heat.

Further, when the magnitude ΔT of the temperature difference between the detected temperatures detected by the air supply port temperature sensor 40 and the exhaust port temperature sensor 41 falls within the predetermined value t _th , the control device 23 ends the preheat drying process. When there is no remaining heat and the evaporator 31 and the condenser 32 have no drying capacity, the circulation fan 26 can be stopped to suppress wasteful power consumption.

  In the present embodiment, a check valve 38 for preventing the refrigerant from flowing back from the compressor 33 side to the evaporator 31 is provided between the evaporator 31 and the compressor 33, and the control device 23 is connected to the compressor 33. In order to close the refrigerant flow path between the condenser 32 and the evaporator 31 by closing the decompression device 34 while the engine is stopped, the compressor 33 in the driving state is stopped and the process proceeds from the drying process to the preheat drying process. In addition, the high-temperature and high-pressure refrigerant staying in the condenser 32 does not flow into the low-temperature evaporator 31, and the condenser 32 and the evaporator 31 can hold heat and cold.

  In addition, the heat pump 30 includes a bypass 36 and an opening / closing valve 37 as pressure difference adjusting means, and the control device 23 opens the opening / closing valve 37 while the compressor 33 is stopped to suck the suction side 33a of the compressor 33. Therefore, the compressor 33 can be started smoothly.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment.

  In the above-described first embodiment, when the energy saving course is selected as the drying operation, the preheating drying process is executed after the drying process and then the circulation fan 26 is stopped to end the preheating drying process and shift to the standby process. However, the present embodiment is different from the first embodiment described above in that when the preheat drying process ends, the compressor 33 is started and the process proceeds to the drying process without performing the standby process.

That is, as shown in FIG. 7, during the remaining heat drying process, the control device 23 detects that the temperature difference magnitude ΔT detected by the supply air temperature sensor 40 and the exhaust air temperature sensor 41 is a predetermined value. It is determined whether or not it is within t _th , and if the detected temperature difference ΔT is within the predetermined value t _th , the process proceeds to step S10 to determine whether or not a predetermined drying end condition is satisfied, and the drying end condition is satisfied. If not, the process returns to the drying process in step S1, and the drying process (steps S1 to S4) and the preheat drying process (steps S5 to S6) are alternately and repeatedly performed until a predetermined drying end condition is satisfied. If the termination condition is satisfied, the drying operation is terminated.

In this embodiment, the magnitude ΔT of the temperature difference between the detected temperatures detected by the air inlet temperature sensor 40 and the exhaust outlet temperature sensor 41 is within a predetermined value t _th , and the evaporator 31 and the condenser 32 have a drying capacity. When it disappears, since the compressor 33 is started and the drying process is restarted, the heat remaining in the evaporator 31 and the condenser 32 is utilized for clothes drying, and the lengthening of the drying time can be suppressed.

  As mentioned above, although embodiment of this invention was described, these embodiment was shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

DESCRIPTION OF SYMBOLS 1 ... Outer box, 1a ... Front part, 2 ... Base plate, 3 ... Laundry doorway, 4 ... Door, 5 ... Hinge, 6 ... Operation display panel, 7 ... Detergent case, 8 ... Water tank, 9 ... Elastic support mechanism DESCRIPTION OF SYMBOLS 10 ... Exhaust port, 11 ... Supply port, 14 ... Rotating tank, 15 ... Hole, 16 ... Baffle, 17 ... Motor, 18 ... Water supply valve, 19 ... Drain valve, 20 ... Circulation air path, 22 ... Heat exchange duct , 23 ... control device, 24 ... exhaust duct, 26 ... circulation fan, 28 ... air supply duct, 29 ... accumulator, 30 ... heat pump, 31 ... evaporator, 32 ... condenser, 33 ... compressor, 34 ... decompression device, 35 ... Accumulator, 36 ... Detour, 37 ... Open / close valve, 38 ... Check valve, 40 ... Supply port temperature sensor, 41 ... Exhaust port temperature sensor, 42 ... Condenser temperature sensor

Claims (4)

A drying chamber having an exhaust port and an air supply port;
A circulation air passage provided outside the drying chamber and connecting the exhaust port and the air supply port;
A circulation fan for circulating the air in the drying chamber through the circulation air passage;
A condenser that heats the air in the circulation air passage, an evaporator that cools and dehumidifies the air in the circulation air passage, a compressor that compresses a refrigerant and supplies the refrigerant to the condenser, and a condenser. A heat pump comprising a decompression means for decompressing the refrigerant,
An air inlet temperature sensor for detecting a temperature of air supplied from the circulation air passage to the drying chamber;
An exhaust port temperature sensor for detecting a temperature of air exhausted from the drying chamber to the circulation air path;
A condenser temperature sensor for detecting the temperature of the condenser;
A controller for controlling the heat pump and the circulation fan,
The control device drives the compressor and the circulation fan to dry clothes in the drying chamber, and the compression device detects the compression temperature when a temperature detected by the condenser temperature sensor becomes equal to or higher than a predetermined temperature during the drying step. A preheat drying step of driving the circulation fan while stopping the machine, and the preheat drying step is terminated when a difference between detected temperatures of the exhaust port temperature sensor and the air supply port temperature sensor becomes a predetermined temperature or less. Clothes dryer.   The clothes dryer according to claim 1, wherein when the difference between detected temperatures of the exhaust port temperature sensor and the air supply port temperature sensor becomes equal to or lower than a predetermined temperature, the circulation fan is stopped and the preheat drying process is ended.   The clothes dryer according to claim 1, wherein when the difference between detected temperatures of the exhaust port temperature sensor and the air supply port temperature sensor becomes equal to or lower than a predetermined temperature, the compressor is driven to finish the preheat drying process.   The heat pump includes pressure difference adjusting means for balancing a pressure difference between the suction side and the discharge side of the compressor while the compressor is stopped, and from the condenser side to the evaporator side when the compressor is stopped. And a check valve that is provided between the evaporator and the compressor and prevents a reverse flow of the refrigerant from the compressor side to the evaporator side. 4. The clothes dryer according to any one of 3 above.

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