JP2009195362A - Clothes dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce washing/drying time by increasing the temperature of an evaporator when drying clothes at low ambient temperatures. <P>SOLUTION: A heat source of the clothes dryer has a heat pump device. The time of retaining the temperature at 0°C or lower in a condenser 23 accompanying evaporation is reduced by changing the flow of a refrigerant so that the condenser 23 evaporates the refrigerant at low ambient temperature. With this structure, frost formation and growth to ice in the condenser 23 which performs the evaporation can be inhibited, and blocking of ventilation caused by the clogging of a heat exchanger (the condenser 23) accompanying the evaporation and extension of the drying time caused by the blocked ventilation can be prevented, and as a result, the drying time can be reduced and the power consumption can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drying apparatus for drying clothes, bedding, etc. in a non-dry state after washing.

  The configuration and operation of this conventional drying apparatus will be described with reference to FIG.

  FIG. 4 shows a conventional drum-type washing / drying machine, in which a cylindrical water tank 53 elastically supported by a plurality of suspensions 52 is provided inside a casing 51 to vibrate vibration during washing and dehydration. It is configured to be absorbed by the suspension 52.

  In addition, a cylindrical and horizontal axis type rotating tank 55 that accommodates what is to be dried 54 (hereinafter referred to as clothing 54) to be washed or dried such as clothes is rotatably provided inside the water tank 53. Then, the rotary shaft 56a is rotated by the drive motor 56 to drive the rotation.

  A plurality of baffles (not shown) for stirring the clothes 54 are provided on the inner wall of the rotating tank 55, and a plurality of small holes 55 a are provided on the peripheral wall of the rotating tank 55.

  On the front surface of the housing 51, an opening 51a for taking in and out the clothes 54 and a door 57 for opening and closing the same are provided. Further, the front side of the water tank 53 and the rotary tank 55 have similar openings 53 a and 55 b, respectively. Further, the opening 53 a of the water tank 53 is watertightly connected to the opening 51 a of the housing 51 by the bellows 58. ing.

  The bottom of the water tank 53 has a drain 59 for discharging washing water, and the drain 59 is connected to a drain hose 61 via a drain valve 60, and its tip is outside the washing and drying machine. Has been derived.

  The blower 62 blows and supplies the warm air heated by the heater 63 from the air supply port 64 into the rotary tank 55.

  The circulation duct 65 passes through the rotary tank 55 and the water tank 53 and dehumidifies the damp drying air. One end of the circulation duct 65 is connected to the exhaust port 66 below the water tank 53 and the other end is connected to the blower 62. Yes.

  The water supply valve 67 controls water supply from a water supply hose 68 connected to a faucet (not shown) of a water supply.

  The operation of the conventional washing and drying machine configured as described above is as follows.

  When performing the washing operation, the door 57 is opened, the clothes 54 and the detergent are put into the rotating tub 55, and the operation is started.

  First, the water supply valve 67 opens a water supply port (not shown) on the washing water side, and when a predetermined amount of water is supplied into the water tank 53 and the rotary tank 55, the drive motor 56 operates to rotate. The tank 55 is rotationally driven to perform a cleaning operation.

  After a predetermined time, the drive motor 56 is stopped, the drain valve 60 is opened, and dirty water is drained from the rotary tank 55 and the water tank 53 and drained to the drainage place outside the washing dryer through the drain hose 61.

  Next, water is supplied to the water tank 53 and the rotating tank 55 in the same manner as described above, and a rinsing operation is performed.

  When the rinsing is completed, the drain valve 60 is opened and drained, and then the rotary tank 55 is driven to rotate at high speed by the drive motor 56, whereby the clothes 54 are dehydrated.

  When the washing / rinsing operation is completed as described above, the drying operation is started.

  In the drying process, the rotary tub 55 is driven to rotate at a low speed by the drive motor 56, and the warm air heated by the heater 63 is blown in the direction of arrow a by the blower 62 while stirring the clothes 54 and supplied through the blower passage 69. It is fed into the rotary tank 55 from the air vent 64 as shown by the arrow b. The hot air takes away moisture from the clothes 54, passes through the water tank 53 through the small hole 55 a of the rotating tank 55, and reaches the circulation duct 65 through the exhaust port 66.

  At this time, the water supply valve 67 opens the water supply port on the cooling water side, and as a result, cooling water is poured into the circulation duct 65.

  When the hot air containing moisture from the moisture of the clothing 54 passes through the circulation duct 65, it is cooled by the cooling water to cause moisture condensation, and the wet hot air is dehumidified by the condensation, and the arrow c As shown, the flow returns to the blower 62 again.

  The cooling water and dew condensation water are drained out of the washing / drying machine through a drain valve 60.

  As described above, the conventional washing / drying machine circulates the hot air in the circulation path of the heater 63, the blower 62, the air supply port 64, the rotary tank 55, the water tank 53, the exhaust port 66, and the circulation duct 65, thereby rotating the rotary tank. The clothes 54 in 55 can be dried.

  However, in the configuration of the above conventional washer-dryer, the heat used for drying the clothes 54 is all discarded to the outside by the cooling water of the circulation duct 65 or the heat radiation from the casing 51, and is reused. It never happened.

  Therefore, a compressor that compresses the refrigerant, a cooler that dissipates the heat of the compressed refrigerant, a throttle means for reducing the pressure of the high-pressure refrigerant, and heat from the surroundings by the reduced-pressure and low-pressure refrigerant. It has been proposed that a washer / dryer be provided with a heat pump device configured by connecting a condenser to be taken away by a pipe line so that a refrigerant circulates (see, for example, Patent Document 1).

According to this configuration, the moisture evaporated from the clothing can be condensed on the evaporator so that the clothing can be efficiently dried, and the heat of the warm air containing moisture from the clothing is absorbed by the evaporator, which is the refrigerant. Then, the heat of the refrigerant sent to the compressor via the air and heated by the compressor is dissipated by the condenser to reheat the warm air, so that the heat can be effectively utilized.
JP 7-178289 A

  In a heat pump type clothing drying device, the moisture of clothing wet with a cooler is dehumidified to become an evaporation source for the refrigeration cycle, and an electric input for driving the compressor is added and air is heated with a condenser. Furthermore, the operation of evaporating the moisture of the clothing is repeated.

  However, in the conventional heat pump type clothes drying apparatus, it takes time for the clothes to warm up and be used as a condensation source for the refrigeration cycle, and during this time, the compressor pressure is unlikely to rise.

  Therefore, when the temperature of clothing is low, especially when the outside air temperature is low, such as in winter, and the temperature of the washing / drying machine itself is low, the temperature of the air circulating in the evaporator and condenser constituting the refrigeration cycle is also low. In order to exchange heat with the air, unless the temperature of the refrigerant flowing through the evaporator is controlled to be lower than that of the air, energy from the air cannot be used for evaporation.

  For this reason, until the temperature of the circulating air reaches a certain temperature or higher, the temperature of the refrigerant flowing through the evaporator becomes 0 ° C. or less, and the moisture condensed by the evaporator at this time is formed on the surface of the evaporator with frost or ice. Therefore, it becomes resistance of the flow of the circulating air and also prevents heat exchange between the refrigerant and the air.

  In the condenser, since the circulating air is cooled as it goes downstream, the temperature on the downstream side becomes the lowest. From this point, the growth of frost and ice begins, and the resistance of the circulating air is increased. Air heat exchange will be hindered.

  Further, until the circulating air rises to a certain temperature, the generated frost repeatedly grows and melts on the surface of the evaporator, and the melted water is re-iced while flowing down to the lower surface side of the evaporator. For this reason, there existed a subject that it became the resistance of the air which the refrosted frost circulates, and prevented heat exchange with a refrigerant | coolant and air.

  In addition, if frost or ice grows in the evaporator and the heat exchange between the air and the refrigerant is not sufficient, the refrigerant will not be completely evaporated and will be sucked into the compressor in the liquid state. There was also a problem that it also affected.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to provide a clothes drying apparatus that suppresses the growth of frost and ice in an evaporator even in a situation where the outside air temperature is low.

  In order to solve the above-described conventional problems, a clothes drying apparatus according to the present invention is a clothes drying apparatus provided with a refrigerant circulation circuit serving as a heat source of drying air supplied into a water tank that forms a drying space. When the temperature of the refrigerant is low, the refrigerant flow in the refrigerant circulation circuit is changed so that the refrigerant discharged from the compressor flows into the evaporator having a smaller heat exchange capacity than the condenser.

  As a result, when the outside air temperature is low or the dry air temperature is equal to or lower than a predetermined value, the evaporator in the refrigerant circulation circuit performs the condensing action of the circulating refrigerant for a predetermined time, and the condenser performs the evaporating action of the circulating refrigerant. As a result, while the evaporator is performing the condensing action, the capacity of the condenser that performs the evaporating action is large, the temperature drop due to the evaporating action is slowed, and the frosting of moisture contained in the circulating air is also suppressed, Moisture tends to adhere to the condenser as dew.

  Therefore, the adhesion of frost to the condenser performing the evaporation action can be suppressed, and the increase in circulation resistance of the circulating air due to the frost adhesion at the beginning of operation is suppressed, thereby improving the heat exchange efficiency between the refrigerant and the air. be able to. As a result, the water evaporated from the clothes in the non-dry state is easily attached to the evaporator, and the drying time can be shortened and the power consumption can be reduced.

  Furthermore, since sufficient heat exchange between the air and the refrigerant can be achieved, the evaporation of the refrigerant is activated, and the suction of the liquid refrigerant into the compressor can be suppressed.

  The clothing drying apparatus of the present invention makes it difficult to reduce the temperature of the condenser that performs the evaporating action at the start of operation at a low outside air temperature or the like, and shortens the time during which the evaporator maintains a temperature below the freezing point within a predetermined time. As a result, it suppresses frost formation and ice growth in the condenser that performs the evaporating action, improves the circulation of dry air and suppresses the decrease in drying efficiency, shortens the drying time, and reduces power consumption Further, by promoting the evaporation of the refrigerant in the evaporator, the return of the liquid refrigerant to the compressor and the breakage of the compressor due to the liquid compressor can be suppressed.

  The invention according to claim 1 is a main body provided with a bottomed cylindrical water tank, a rotary drum rotatably disposed in the water tank, and a garment or the like placed on the rotary drum. A clothes drying device comprising an opening that enables opening, a lid that opens and closes the opening, and an air circulation device that circulates air in the water tank, wherein the air circulation device cools at least the circulating air A heat source device for heating, a circulation duct provided on both sides of the heat source device and having both ends opened in the water tank, and provided in the heat source device or the circulation duct, and circulating air from the heat source device into the water tank The heat source device comprises a compressor, a condenser through which the refrigerant discharged from the compressor flows, a decompression unit, an evaporator having a smaller heat exchange capacity than the condenser, and a flow of refrigerant discharged from the compressor The A refrigerant circulation circuit having a switching device for switching from the evaporator side to the evaporator side, further detecting temperature inside or outside the main body, and a low temperature at which the temperature detecting means is a predetermined value or less Is provided with flow path switching means for operating the switching device so that the refrigerant discharged from the compressor flows to the evaporator side.

  By adopting such a configuration, when the outside air temperature or the dry air temperature is a predetermined value or less, the capacity of the condenser that performs the evaporating action is increased to slow down the temperature decrease rate of the condenser accompanying the evaporating action, The temperature maintenance time of 0 ° C. or lower within a predetermined time of the condenser during the evaporation operation can be shortened. As a result, since the condenser in the evaporating action is in a temperature condition suitable for dew deposition, frost can be prevented from adhering to ice, and ventilation resistance of circulating air accompanying the above-mentioned ice growth can be suppressed. The heat exchange efficiency between the refrigerant and the air can be increased.

  Therefore, moisture evaporated from clothes in a non-dry state etc. is likely to adhere to the condenser that is evaporating in the dew state, suppressing a decrease in drying efficiency, shortening the drying time, and reducing power consumption Reduction can be made possible.

  Further, since the heat exchange between the air and the refrigerant can be sufficiently performed by increasing the evaporation capacity in the evaporator, the evaporation of the refrigerant is activated and the suction of the liquid refrigerant in the compressor is suppressed, and the compressor caused by this Damage can be prevented.

  According to a second aspect of the present invention, in the clothes drying apparatus according to the first aspect, during the operation of the flow path switching means, the air circulation direction by the air circulation device is controlled in the reverse direction, and the condenser is on the windward side. It was made to become.

  By adopting such a configuration, the circulating air in the initial operation is cooled and dehumidified, and then the temperature is raised to dry air with a low relative humidity, so that the operation can be performed with high drying efficiency from the initial operation and the drying time is shortened. In addition, the power consumption can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view of an oblique drum type washing and drying machine according to Embodiment 1 of the present invention. FIG. 2 is a schematic diagram showing a system configuration of the oblique drum type washing and drying machine. FIG. 3 is a time chart showing the control contents at the low outside air temperature in the oblique drum type washing and drying machine.

  As shown in FIG. 1, a bottomed cylindrical water tank 3 elastically supported by a plurality of suspensions 2 is provided inside a casing 1 constituting the main body of the washing and drying machine. The suspension 2 absorbs vibration of the water tank 3.

  Inside the water tank 3, there are provided a plurality of through holes 5 a in the peripheral wall, and a bottomed cylindrical and horizontal axis type rotary drum 5 that accommodates the clothes 4 is rotatably provided. Is done. On the front surface of the housing 1, there are provided an opening 1a for taking in and out the garment 4 and a door 7 for opening and closing the opening 1a.

  The front side of the water tank 3 and the rotating drum 5 also have similar openings 3a and 5b, respectively. The opening 3a of the water tank 3 is watertightly connected to the opening 1a of the housing 1 by appropriate means such as a bellows 8 or the like. ing. A seal member 12 is provided between the water tank 3 and the rotating drum 5 to partition the opening 3 a side and the bottom side in a space formed by the water tank 3 and the rotating drum 5. The seal member 12 is arranged with a minute interval so as not to contact the rotating drum 5. Further, a drain port 3 b for discharging the washing water in the water tank 3 is provided at the bottom of the water tank 3, and is connected to a drain hose 10 having a drain valve 9.

  The blower 11 constituting the blowing means includes a fan 11a and a motor 11b for driving the fan 11a, and is located in a corner space (upper part of the casing 1) formed by the upper surface 1b of the casing 1 and the water tank 3. It is provided as follows. An evaporator (heat absorber) 21 and a condenser (heat radiator) 23, which are fin-tube heat exchangers constituting the heat pump device 20 (FIG. 2), are arranged close to each other at the lower part of the rear surface 1c of the housing 1. And the accommodated heat exchange air path 25 is arrange | positioned.

  Inside the heat exchange air passage 25, there are provided a heat absorber air passage 22 through which air flows from the direction of arrow b to the evaporator 21, and a radiator air passage 24 through which air flows from the condenser 23 in the direction of arrow c. It has been.

  Further, the heat absorber air passage 22 is connected to a discharge duct 26 communicating with the discharge side of the blower 11, and the radiator air passage 24 is connected to an air supply duct 27 opened in the water tank 3.

  The water tank 3 and the suction side of the blower 11 are connected by an exhaust duct 28, and a filter 29 that captures washing waste, yarn waste, and the like scattered with drying is provided in the middle of the exhaust duct 28 in a detachable manner. Yes.

  Here, the heat exchange air passage 25, the discharge duct 26, the air supply duct 27, and the exhaust duct 28 correspond to the circulation duct of the present invention.

  Therefore, the drying air blown by the blower 11 flows from the discharge duct 26 to the heat absorber air passage 22 as shown by the arrow a, passes through the evaporator 21 and the condenser 23, and is supplied as shown by the arrow c. It flows into the air duct 27, flows through the air supply duct 27 as shown by the arrow d, and flows into the water tank 3 from an air supply port (not shown) provided in the water tank 3.

  And it flows to the peripheral wall side of the rotating drum 5, is blocked by the sealing member 12, flows into the rotating drum 5 from a large number of through holes 5a as indicated by an arrow e, and is provided outside the water tank 3 as indicated by an arrow f. From the exhaust port (not shown) through the exhaust duct 28 and back to the suction side of the blower 11, the above flow is performed for a predetermined time.

  Further, the discharge duct 26 is provided with a temperature detector 30 (corresponding to the temperature detecting means of the present invention) for detecting the temperature of the air flowing through the blower 11. The temperature detector 30 is provided with a temperature detecting element such as a thermistor, and is not limited to the air temperature inside the main body, but may detect the air temperature around the washing / drying machine. Good.

  As shown in FIG. 2, the heat pump device (corresponding to the heat source device of the present invention) 20 has a configuration in which a compressor 31, a condenser 23, an electric expansion valve 34 that is a decompression means, and an evaporator 21 are connected in an annular shape.

  On the discharge side of the compressor 31, a four-way valve (corresponding to the switching device of the present invention) 32 for switching the flow of the discharged refrigerant between the condenser 23 side and the evaporator 21 side is provided. When the temperature detected by the temperature detector 30 is equal to or lower than a predetermined temperature value (for example, 5 ° C.), the four-way valve 32 is rotated in the direction of the arrow X by the control device 33 constituting the flow path switching means, as shown in FIG. It stops in the state (B position) and normally rotates in the opposite direction of the arrow X, and maintains the state where the refrigerant discharged from the compressor 31 flows to the condenser 23 (A position). In the following description, for the sake of convenience, the operation of the four-way valve 32 in the state of FIG. 2 will be referred to as B operation, and the operation of rotating in the opposite arrow X direction will be referred to as A operation.

  Further, the condenser 23 has a heat exchange capacity larger than that of the evaporator 21, for example, by making the refrigerant flow path length longer than that of the evaporator 21.

  Further, in addition to the switching control of the four-way valve 32, the control device 33 performs a timer control for controlling the four-way valve 32 to return from the B operation to the A operation after continuing this switching control for a predetermined time ΔT1, and between the timer control. Control that reversely rotates the blower 11 and returns to normal rotation after a predetermined time ΔT1 has passed, control that also adjusts the opening of the electric expansion valve 34 based on the temperature detected by the temperature detector 30, and rotation of the compressor 31 With this control, the pressure in the refrigerant circulation circuit of the heat pump device 20 can be properly maintained, and the temperature of the compressor 31 can be excessively increased by adjusting the opening of the electric expansion valve 34. Can be suppressed. Here, the contents of control related to the present invention will be described.

  Next, main operations of the washing / drying machine having the above-described configuration will be described. Here, the operation described below is a case where the outside air temperature (the ambient temperature of the washing / drying machine or the circulating air temperature) is relatively high.

  In the washing (washing) process, water is supplied into the water tank 3 by opening a water supply valve (not shown) with the drain valve 9 closed. Water is supplied into the water tank 3 until a predetermined water level is reached, and the drive motor 6 is driven to rotate the clothes 4 and the rotating drum 5 containing the washing water to perform washing. When the washing is finished, the drain valve 9 is opened, and the water in the water tank 3 is drained from the drain hose 10 to the outside of the washing dryer.

  Also in the next rinsing step after washing, water is supplied into the water tank 3 as in the above-described washing step, and then the garment 4 is rinsed by rotating the rotating drum 5. When rinsing is completed, the drain valve 9 is opened, and the water in the water tank 3 is drained from the drain hose 10 to the outside of the washing dryer.

  In the next dewatering step, the drain valve 9 is opened to drain the water in the water tank 3 from the drain hose 10 to the outside of the washing and drying machine, and then the rotating drum 5 containing the clothes 4 is fastened in one direction by the drive motor 6. It spins and dehydrates by its centrifugal force.

  And when the above-mentioned dehydration process is completed, it will move to a drying process. In this drying process, the compressor 31 of the heat pump apparatus 20 is operated. As a result, the refrigerant is compressed, and this pressure circulates through the condenser 23, the electric expansion valve 34, and the evaporator 21. The condenser 23 releases the heat of the refrigerant, and the evaporator 21 absorbs the heat by the refrigerant that has been decompressed by the electric expansion valve 34 to a low pressure. In parallel with this, the blower 11 is operated, and warm air heated by the heat radiation of the condenser 23 is blown into the water tank 3 through the supply duct 27 from the supply port. At this time, the rotary drum 5 is rotationally driven by the drive motor 6, and the garment 4 is stirred up and down.

  Therefore, the drying air heated by the condenser 23 is blown into the rotary drum 5 from the air supply port by the blower 11. The hot air supplied into the rotating drum 5 takes moisture when passing through the gaps of the clothing 4, passes through the blower 11 from the exhaust duct 28 through the exhaust port of the water tank 3 in the wet state, and exchanges heat from the discharge duct 26. It flows to the air path 25 and reaches the evaporator 21.

  When the wet warm air passes through the evaporator 21, sensible heat and latent heat are taken away and dehumidified, and separated into dry air and condensed water.

  When the dried air subsequently passes through the condenser 23, it is heated again by the condenser 23 to become hot air, and is supplied again into the water tank 3 and the rotating drum 5, and the above-described circulation is repeated thereafter.

  On the other hand, when the condensed water adheres to the evaporator 21 and saturates and falls, the condensed water is stored in a water storage chamber (not shown) provided at the lower portion and pumped up by a drain pump (not shown) and drained hose. 10 is discharged outside the machine.

  In this way, by using the heat pump device 20 for drying the clothing 4 and the like, the heat absorbed by the evaporator 21 is recovered by the refrigerant and radiated again by the condenser 23, and the amount of heat more than the input energy of the compressor 31 is obtained. Since it can give to the clothing 4, a drying efficiency can be improved. Therefore, shortening of the drying time and energy saving can be realized.

  In the drying step, when the outside air temperature (the room temperature or the circulating air temperature) is a predetermined value or higher, for example, 5 ° C. or higher, the electric expansion valve 34 in the heat pump device 20 is decompressed by the controller 33. And the evaporator 21 also acts to have a predetermined low temperature.

  On the other hand, when the outside air temperature is a predetermined value (for example, 5 ° C.) or less, when the heat pump device 20 is operated at the same degree of decompression at a so-called low outside air temperature, the evaporator 21 becomes a transiently low temperature, and as a result, clothing When the dried air containing moisture such as 4 is passed through the evaporator 21, the moisture freezes and becomes frost, and if the operation is continued, the evaporator 21 freezes and moisture cannot be condensed. Ventilation through the evaporator 21 is not possible, so that the fins are clogged and cannot be dried.

  Next, the drying operation at a low outside air temperature will be described. Here, since the washing process to the dehydration process are the same as described above, the description thereof will be omitted and the drying process will be described here.

  When the outside air temperature is low, the temperature detector 30 detects the temperature, and the four-way valve 32 is in the B state as shown in FIG. As a result, the refrigerant discharged from the compressor 31 flows from the four-way valve 32 to the evaporator 21, flows to the condenser 23 through the electric expansion valve 34, and returns to the compressor 31 to form a so-called reverse cycle. It becomes.

  Moreover, since the capacity | capacitance of the condenser 23 is formed larger than the capacity | capacitance of the evaporator 21, predetermined | prescribed time (DELTA) T1 WHEREIN: In the condenser 23 which performs the evaporation action of a refrigerant | coolant, it is temperature rather than the evaporation action by the evaporator 21 at the normal time. , The time for maintaining the temperature below 0 ° C. can be shortened, and the refrigerant evaporating action in the condenser 23 is enhanced.

  At this time, by controlling the opening degree of the electric expansion valve 34 to be slightly larger, the temperature of the refrigerant flowing to the condenser 23 is also slightly higher, and the transient cooling action (low temperature) of the condenser 23 is suppressed. be able to.

  In this state, when the blower 11 is operated in reverse rotation and the compressor 31 is operated, the refrigerant flows through the evaporator 21, the electric expansion valve 34, and the condenser 23, and returns to the compressor 31. In this refrigerant flow, the evaporator 21 condenses the refrigerant, and the condenser 23 evaporates the refrigerant.

  In this way, by using the refrigerant circulation as the reverse cycle and subjecting the condenser 23 having a larger heat exchange capacity than the evaporator 21 to the evaporating action, the temperature decrease as the evaporator is dulled and the rate of decrease is slowed down. Then, the time during which the condenser 23 that performs the evaporation action maintains a temperature of 0 ° C. or less can be shortened as much as possible, and as a result, moisture contained in the circulating dry air becomes dew and easily adheres to the condenser 23. And frost formation is suppressed.

  Further, by subjecting the condenser 23 to the evaporating action, the evaporating ability is increased, and the refrigerant flowing through the evaporating condenser 23 is promoted to evaporate (gasification), so that the return refrigerant is liquefied. The accompanying liquid compression of the compressor 31 can also be suppressed, and damage to the compressor 31 can be prevented.

  In addition, by reducing the degree of pressure reduction by the electric expansion valve 34, it is possible to suppress the evaporator 21 from being maintained at a sudden low temperature (0 ° C. or lower).

  Furthermore, by setting the blower 11 in the reverse rotation operation, the dry air flows from the intake duct 27 to the condenser 23 side as shown by the broken line arrow in FIG. 2, and passes through the condenser 23 that performs the evaporation of the refrigerant. It becomes a flow which passes the evaporator 21 which performs the condensation action of a refrigerant | coolant later.

  Therefore, even during that time, when passing through the condenser 23, the moisture of the dry air becomes dew and adheres to the condenser 23, and then the evaporator 21 that performs the condensing action lowers the relative humidity and is used for drying. Is done.

  Since this dry air becomes air having a low relative humidity, the process of once cooling and then raising the temperature is the same as in normal operation when the outside air temperature is 5 ° C. or higher.

  In this state, when the operating frequency of the compressor 31 is controlled to be gradually higher as f1, f2, and f3, and the input energy of the compressor 31 is gradually increased, the temperature of the evaporator 21 that performs the condensation action is gradually increased accordingly. The temperature of the circulating dry air gradually increases.

  When the control device 33 measures ΔT1 for a predetermined time (the compressor 31 is temporarily stopped if necessary), the four-way valve 32 is in the A operation, and the refrigerant discharged from the compressor 31 And a forward cycle is formed. As a result, the temperature of the refrigerant flowing through the evaporator 21 is controlled to a temperature at which moisture contained in the circulating dry air is likely to condense.

  In parallel with this, the rotation direction of the blower 11 is controlled to be the normal rotation direction, that is, the same direction as when the circulating dry air is equal to or higher than the predetermined value of the outside air temperature, and the electric expansion valve 34 is also The opening degree is controlled, and the pressure in the refrigerant circuit is maintained at an optimum value. Such a state is set to a value at which the heat pump device 20 can exhibit high efficiency, and both the heat radiation amount and the heat absorption amount by the heat pump device 20 are increased, and the humidity of the dry air can be lowered to increase the drying efficiency.

  In the first embodiment, the control device 33 has a timer function, and after the predetermined time ΔT1 is measured, the flow direction of the refrigerant is switched, and the operation of the condenser 23 is returned to the normal condensing operation. It can also be set as control which switches the flow direction of a refrigerant with the temperature which temperature detector 30 detects.

  That is, the dry air temperature in the discharge duct 26 detected by the temperature detector 30 is a temperature at which frosting is unlikely to occur in the evaporator 21 as in normal operation (operation when the outside air temperature is 5 ° C. or higher). When the four-way valve 32 is set to the A operation, the same effect can be expected.

  Therefore, according to the first embodiment, frost adherence to the evaporator 21 due to a transient temperature drop of the evaporator 21 at the time of starting the drying process at a low outside air temperature, growth on ice, and The obstruction of the resulting ventilation can be prevented and a continuous drying process can be formed. As a result, it is possible to reduce the moisture of the circulating dry air, and to efficiently dry an object to be dried such as clothing. As a result, the drying time can be shortened and the power consumption can be reduced.

  Further, since the temperature detector 30 detects the air temperature before passing through the evaporator 21, it detects a temperature close to the temperature in the rotary drum 5, so that the circulating air temperature and the predetermined value temperature can be detected more. This can be performed with high accuracy, and the reliability of suppressing the low temperature of the evaporator 21 can be enhanced.

  In the first embodiment, the blower 11 and the temperature detector 30 are provided on the discharge duct 26 side. However, as indicated by the broken line, the heat pump device is provided on the air supply duct 27 side or is a heat source device. 20 may be incorporated.

  Further, instead of the four-way valve 32, the refrigerant flow path may be switched by a plurality of electromagnetic on-off valves.

  Further, the decompression means is not limited to the electric expansion valve 34 whose degree of decompression can be changed according to the heat load, and a decompression means having a constant degree of decompression, such as a capillary tube, can be used.

  Further, the compressor 31 is controlled by the inverter control device so that its rotation speed (capacity) is well known, but may be a compressor operated at a constant speed.

  Furthermore, the present invention can be similarly applied to a drying apparatus such as a so-called garment that does not have a washing function.

  The heat pump type clothing drying apparatus according to the present invention changes the refrigerant flow for a certain period of time by the action of the temperature detector at a low outside air temperature, and suppresses the growth of frost and ice in the evaporator even under a low outside air temperature. It is possible to obtain a configuration in which frost does not easily adhere to the evaporator at low outside air temperature, does not become resistance of circulating air, and does not hinder heat exchange between refrigerant and air. It can be widely applied to an article drying apparatus that dislikes moisture, such as grain drying.

Sectional drawing of the diagonal drum type washing-drying machine in Embodiment 1 of this invention Schematic diagram showing the system configuration of the oblique drum type washing and drying machine Time chart showing the control contents at low outside air temperature in the diagonal drum type washing and drying machine Sectional view of a conventional drum-type washing and drying machine

Explanation of symbols

1 Housing (main body)
1a Opening 3 Water tank 4 Clothes 5 Rotating drum 7 Door (lid)
11 Blower 20 Heat pump device (heat source device)
21 Evaporator 23 Condenser 25 Heat exchange air passage (circulation duct)
26 Discharge duct (circulation duct)
27 Air supply duct (circulation duct)
28 Exhaust duct (circulation duct)
30 Temperature detector (temperature detection means)
31 Compressor 32 Four-way valve (switching device)
33 Control device (flow path switching means)
34 Electric expansion valve (pressure reduction means)

Claims (2)

  A main body provided with a bottomed cylindrical water tank, a rotating drum rotatably disposed in the water tank, an opening provided in the main body and allowing clothes or the like to be put into the rotating drum, A clothes drying apparatus comprising a lid that opens and closes an opening, and an air circulation device that circulates air in the water tank, wherein the air circulation device includes at least a heat source device that cools and heats the circulating air, and the heat source. The heat source comprises a circulation duct that is provided across the apparatus and has both ends opened in the water tank, and a circulation fan that is provided in the heat source apparatus or the circulation duct and circulates air from the heat source apparatus into the water tank. A compressor, a condenser through which a refrigerant discharged from the compressor flows, a decompression unit, an evaporator having a smaller heat exchange capacity than the condenser, and a flow of the refrigerant discharged from the compressor from the condenser side to the evaporator On the side A refrigerant circulation circuit having a switching device for switching, and further, a temperature detecting means for detecting a temperature inside or outside the main body, and the compression when the temperature detecting means detects a low temperature below a predetermined value. A clothes drying apparatus provided with flow path switching means for operating the switching apparatus so that the refrigerant discharged from the machine flows to the evaporator side.   2. The clothes drying apparatus according to claim 1, wherein when the flow path switching unit is operated, the air circulation direction of the air circulation device is controlled in the reverse direction so that the condenser is on the windward side.

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