Clothes dryer

Abstract

To achieve an improvement regarding dehumidification of warm air in drying operation.SOLUTION: A clothes dryer includes: a drying chamber; a circulation air passage; a heating device for heating an air passing through the circulation air passage; a first dehumidifying mechanism for dehumidifying the air in the circulation air passage; a second dehumidifying mechanism for dehumidifying the air in the circulation air passage in a mode different from that of the first dehumidifying mechanism; and a control device capable of executing drying operation for driving the heating device to dry clothes in the drying chamber. The first dehumidifying mechanism and the second dehumidifying mechanism are arranged at positions in which the air which flows from the drying chamber into the circulation air passage passes the first dehumidifying mechanism and the second dehumidifying mechanism, and then, flows into the drying chamber again. The second dehumidifying mechanism has an exchange path for exhausting part of warm air passing through the circulation air passage to the outside of the circulation air passage. The control device can execute first dehumidifying processing for performing dehumidification by the first dehumidifying mechanism and second dehumidifying processing for performing dehumidification by the second dehumidifying mechanism during drying operation, and executes the first dehumidifying processing before the second dehumidifying processing, and finishes the second dehumidifying processing after finishing the first dehumidifying processing.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] Embodiments of the present invention relate to a clothes dryer.

Background Art

[0002] Conventionally, in a clothes dryer, in order to improve the drying efficiency, the warm air after removing moisture from the clothes is dehumidified and reused for drying. Examples of the dehumidification method in this case include an air-cooling type and a water-cooling type. The air-cooling type is a method of cooling and dehumidifying the warm air after drying by the outside air taken in from outside the machine, and the water-cooling type is a method of cooling and dehumidifying the warm air by cooling water.

[0003] Here, in the case of the air-cooling type, the outside air taken into the machine for cooling is discharged outside the machine again after cooling the warm air after drying and rising in temperature. Therefore, the environmental temperature around the clothes dryer rises due to the air discharged outside the machine, thereby reducing the performance of cooling and dehumidification by taking in the outside air, and there is also a possibility of giving discomfort to the user depending on the season. In addition, in the case of the water-cooling type, it is common to use tap water for cooling the warm air after drying. In this case, a large amount of tap water is used each time the drying operation is performed, so it is more uneconomical than the air-cooling type.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

Means for Solving the Problems

[0006] Note: There seems to be an error in tag in the original text which is repeated in the translation. Also,

[0005] seems to be an incorrect tag in the original as it's missing in the translation contextually. These might be issues with the original text formatting.The clothes dryer of the embodiment includes a drying chamber capable of accommodating clothes, a circulating air passage that returns at least a portion of the air flowing out of the drying chamber back to the drying chamber, a heating device that heats the air passing through the circulating air passage, a first dehumidification mechanism that dehumidifies the air in the circulating air passage, a second dehumidification mechanism that dehumidifies the air in the circulating air passage in a manner different from that of the first dehumidification mechanism, and a control device that drives the heating device to perform a drying operation to dry the clothes in the drying chamber. The dehumidification method of the first dehumidification mechanism is a water-cooling type that cools and dehumidifies the air in the circulating air passage by supplying water into the circulating air passage. The dehumidification method of the second dehumidification mechanism is an air-exchange type that dehumidifies the air in the circulating air passage by exchanging the air in the circulating air passage with outside air. The first dehumidification mechanism and the second dehumidification mechanism are positioned so that air flowing out of the drying chamber into the circulating air passage passes through the first dehumidification mechanism and the second dehumidification mechanism and flows back into the drying chamber. The second dehumidification mechanism has an exchange path that connects the outside and inside of the circulating air passage and discharges a portion of the warm air passing through the circulating air passage to the outside of the circulating air passage. The control device is capable of performing a first dehumidification process using the first dehumidification mechanism and a second dehumidification process using the second dehumidification mechanism during the drying operation, and performs the first dehumidification process before the second dehumidification process, and finishes the second dehumidification process after the first dehumidification process is completed. [Brief explanation of the drawing]

[0007] [Figure 1] This diagram shows an example of the schematic configuration of a clothes dryer according to one embodiment, and illustrates a state in which the first and second dehumidification mechanisms are not operating. [Figure 2] This diagram shows an example of the schematic configuration of a clothes dryer according to one embodiment, illustrating a state in which the first dehumidification mechanism is operating and the second dehumidification mechanism is not operating. [Figure 3] This diagram shows an example of the schematic configuration of a clothes dryer according to one embodiment, illustrating a state where the first dehumidification mechanism is not operating and the second dehumidification mechanism is operating. [Figure 4] Block diagram showing an example of the electrical configuration of a clothes dryer according to one embodiment. [Figure 5] This diagram shows an example of a drying operation performed in a clothes dryer according to one embodiment, illustrating the input of the heating device, the temperature related to the drying operation, the rotation speed of the blower, and the operating status of the first and second dehumidification mechanisms over time. [Figure 6] This diagram shows, over time, the input of the heating device, the temperature related to the drying operation, the rotation speed of the blower, and the operating states of the first and second dehumidification mechanisms, as another example of the drying operation performed in a clothes dryer according to one embodiment. [Modes for carrying out the invention]

[0008] The following describes one embodiment with reference to the drawings. The washing machine 10 illustrated in Figure 1 is an example of a garment processing device capable of performing predetermined processes on clothes, in this case, at least a washing process to wash clothes, a rinsing process to rinse clothes, and a dewatering process to dewater clothes. The washing machine 10 is also a so-called vertical-axis type washing machine, in which the rotational axis of the rotating drum extends in the vertical direction. Furthermore, the washing machine 10 is also an example of a clothes dryer capable of performing a drying process to dry clothes.

[0009] The clothes dryer of this embodiment can be applied to, for example, a vertical-axis type washer-dryer 10 as shown in Figure 1. Although not shown in detail, the clothes dryer of this embodiment can also be applied to, for example, a horizontal-axis or diagonal-axis type drum-type washing machine. Furthermore, the clothes dryer of this embodiment can also be applied to a clothes dryer that does not have a washing function and is for drying only.

[0010] The washer-dryer 10 shown in Figure 1 comprises an outer casing 11, an outer tub 12, a rotating tub 13, a motor 14, a pulsator 15, a drainage mechanism 16, and a circulating air passage 20. In Figure 1, the side of the washer-dryer 10 facing the installation surface, i.e., the vertically downward side, is considered the lower side of the washer-dryer 10, and the side opposite the installation surface, i.e., the vertically upward side, is considered the upper side of the washer-dryer 10.

[0011] The outer casing 11 constitutes the outer shell of the washer-dryer 10 and houses the outer tub 12, rotating tub 13, motor 14, pulsator 15, drainage mechanism 16, and circulating air passage 20. The outer tub 12 is formed in a bottomed cylindrical shape with an open top. In this embodiment, the outer tub 12 can store water inside and functions as a water tank. The outer tub 12 has a clothing inlet / outlet 121 and an inner lid 122. The clothing inlet / outlet 121 connects the inside and outside of the outer tub 12. The inner lid 122 opens and closes the clothing inlet / outlet 121. With the inner lid 122 open, the user can put clothes into or take them out of the rotating tub 13 through the clothing inlet / outlet 121. The washer-dryer 10 performs washing and drying operations with the inner lid 122 closed.

[0012] The outer tank 12 has a circulation outlet 123 and a circulation inlet 124. The circulation outlet 123 is provided, for example, near the bottom of the peripheral wall that constitutes the cylindrical portion of the outer tank 12. The circulation inlet 124 is provided, for example, on the upper side of the outer tank 12. The circulation outlet 123 and the circulation inlet 124 connect the inside and outside of the outer tank 12.

[0013] The rotating tub 13 is formed in a bottomed cylindrical shape capable of accommodating clothes and is rotatably housed inside the outer tub 12. The axis of rotation of the rotating tub 13 is aligned with the central axis of the outer tub 12. The rotating tub 13 has a plurality of communication holes 131. The communication holes 131 connect the inside and outside of the rotating tub 13. During washing and spinning cycles, the communication holes 131 mainly function as water passages through which water enters and exits, and during drying cycles, they function as ventilation holes through which air enters and exits. The outer tub 12 and the rotating tub 13 function as a drying chamber in which clothes are placed during drying cycles to dry the clothes.

[0014] The motor 14 is located, for example, on the outside of the bottom of the outer tub 12. The motor 14 can be, for example, an outer rotor type direct drive motor. The motor 14 is connected to the rotating tub 13 and the pulsator 15 via a clutch mechanism (not shown). The clutch mechanism (not shown) selectively transmits the rotation of the motor 14 to the rotating tub 13 and the pulsator 15. For example, during washing, rinsing, and drying operations, the motor 14 and the clutch mechanism (not shown) transmit the driving force of the motor 14 to the pulsator 15 with the rotation of the rotating tub 13 stopped, thereby directly driving the pulsator 15 to rotate in both forward and reverse directions at a low speed. On the other hand, during dewatering, etc., the motor 14 and the clutch mechanism (not shown) transmit the driving force of the motor 14 to the rotating tub 13, causing the rotating tub 13 and the pulsator 15 to rotate at high speed in one direction.

[0015] The drainage mechanism 16 has the function of discharging water stored inside the outer tub 12 to the outside of the washing machine 10. The drainage mechanism 16 consists of a drain valve 161 and a drain pipe 162. The drain valve 161 is, for example, an electromagnetically driven on / off valve for liquids. The drain pipe 162 forms a drainage path from inside the outer tub 12 to outside the machine. The drain valve 161 is installed in the middle of the drainage path and opens and closes the drainage path. The washing machine 10 also has a water supply mechanism, although details are not shown. The water supply mechanism, which is not shown, has, for example, a water supply valve 17 as shown in Figure 4, and is connected to an external water source, such as a water supply, and has the function of supplying water supplied from the external water source into the outer tub 12.

[0016] The circulating air passage 20 is located outside the drying chamber, which consists of the outer tank 12 and the rotating tank 13, and is configured to circulate at least a portion of the air inside the outer tank 12 and the rotating tank 13. The circulating air passage 20 connects the circulation outlet 123 and the circulation inlet 124. In this embodiment, the circulating air passage 20 is configured as a semi-open type, and is open into the outer casing 11 midway through the circulating air passage 20.

[0017] That is, in the case of this embodiment, the circulation air passage 20 is configured to include, for example, an exhaust duct 21, a heating chamber 22, and an air supply duct 23. In the following description, among the circulation air passage 20, the circulation outlet 123 of the circulation air passage 20 is taken as the most upstream side of the circulation air passage 20, and the circulation inlet 124 is taken as the most downstream side of the circulation air passage 20 for description.

[0018] The exhaust duct 21 is provided, for example, on the outer peripheral surface of the outer tub 12 and extends in the vertical direction. The upstream side of the exhaust duct 21 is connected to the circulation outlet 123 of the outer tub 12, and the downstream side of the exhaust duct 21 is open inside the outer box 11. The upstream side of the heating chamber 22 is open inside the outer box 11 in the vicinity of the downstream side of the exhaust duct 21, and the downstream side of the heating device 33 is connected to the air supply duct 23. That is, in the case of this embodiment, the downstream side of the exhaust duct 21 is not physically connected to the heating chamber 22. And the air supply duct 23 connects the heating chamber 22 and the outer tub 12.

[0019] Further, the washing and drying machine 10 includes a filter device 31, a blower device 32, and a heating device 33. The filter device 31, the blower device 32, and the heating device 33 are provided in the circulation air passage 20. The filter device 31 is detachably provided, for example, at the downstream end of the exhaust duct 21. The filter device 31 collects dust and foreign matters contained in the air flowing in the circulation air passage 20, in this case, the air discharged from the exhaust duct 21 into the outer box 11.

[0020] The blower device 32 is provided inside the heating chamber 22 or on the upstream side of the heating chamber 22. The blower device 32 can be configured by, for example, a sirocco fan or the like. The blower device 32 sucks a part of the warm air discharged from the exhaust duct 21 together with the air around the heating chamber 22 into the heating chamber 22 and discharges the sucked air toward the air supply duct 23 side. The heating device 33 is provided on the downstream side of the blower device 32 inside the heating chamber 22. The heating device 33 can be configured by, for example, an electric heater or the like and heats the air flowing through the circulation air passage 20.

[0021] In this configuration, the washing and drying machine 10 drives the blower 32 and the heating device 33 to perform a drying operation. When the blower 32 and the heating device 33 are driven, the air discharged from the blower 32 is heated when passing through the heating device 33 to become warm air for drying, and is supplied into the outer tub 12 and the rotating tub 13 from the circulation inlet 124. Then, when the pressure in the outer tub 12 increases due to the supply of warm air, a part of the air in the outer tub 12 flows out from the circulation outlet 123, passes through the exhaust duct 21, and is discharged outside the circulation air passage 20 from the downstream end of the exhaust duct 21.

[0022] And a part of the warm air discharged from the exhaust duct 21 is sucked again into the heating chamber 22 together with the air around the heating chamber 22 by the blowing action of the blower 32. The air sucked into the heating chamber 22 passes through the heating device 33 again to become warm air and is supplied into the outer tub 12. In this way, at least a part of the air flowing out from the outer tub 12 is returned to the outer tub 12 and circulated, so that a drying operation using the warm air generated by the heating device 33 is reused.

[0023] The washing and drying machine 10 also includes a first dehumidifying mechanism 40 and a second dehumidifying mechanism 50. The first dehumidifying mechanism 40 and the second dehumidifying mechanism 50 are provided in the middle of the circulation air passage 20 and have the function of dehumidifying the air circulating in the circulation air passage 20. The first dehumidifying mechanism 40 and the second dehumidifying mechanism 50 have different dehumidifying methods respectively.

[0024] The first dehumidifying mechanism 40 can be configured by, for example, a water-cooled dehumidifying mechanism. In this case, the first dehumidifying mechanism 40 has the function of cooling and dehumidifying the air in the circulation air passage 20 by supplying water into the circulation air passage 20 and using the water. In the following description, the water discharged from the first dehumidifying mechanism 40 may be referred to as cooling water W. The cooling water W is for the purpose of cooling and dehumidifying the warm air in the circulation air passage 20. The first dehumidifying mechanism 40 dehumidifies by lowering the temperature of the air in the exhaust duct 21, for example, by flowing the cooling water W along the inner wall of the exhaust duct 21 as shown in FIG. 2. In this case, the first dehumidifying mechanism 40 can be referred to as a water-cooled dehumidifying mechanism.

[0025] The second dehumidification mechanism 50 can be configured, for example, as an air exchange type dehumidification mechanism. The second dehumidification mechanism 50 has the function of discharging a portion of the air in the circulating air passage 20, which contains a large amount of moisture, to the outside of the circulating air passage 20 and the outer casing 11, and introducing outside air with lower humidity than the air in the circulating air passage 20 into the circulating air passage 20. In other words, the second dehumidification mechanism 50 has the function of dehumidifying the air in the circulating air passage 20 by exchanging the humid air in the circulating air passage 20 with the less humid outside air. In this case, the second dehumidification mechanism 50 can be called an air exchange dehumidification mechanism. Note that this air exchange type dehumidification mechanism has a different dehumidification principle from the so-called air-cooled type, which dehumidifies by directly cooling the circulating air passage 20 with outside air.

[0026] When the first dehumidification mechanism 40 is a water-cooled dehumidification mechanism, the first dehumidification mechanism 40 can be configured to include, for example, a water supply unit 41 and a dehumidification valve 42. The water supply unit 41 is provided near the downstream end of the exhaust duct 21. The water supply unit 41 is connected to a water source such as a water tap via the dehumidification valve 42. The dehumidification valve 42 can be configured as a solenoid valve for liquids.

[0027] When the dehumidification valve 42 is opened, tap water or the like is supplied from the water supply unit 41 as cooling water W into the exhaust duct 21, as shown in Figure 2. The warm air that has removed moisture from the clothes in the outer tank 12 and the rotating tank 13 is cooled by the cooling water W supplied from the water supply unit 41 in the exhaust duct 21, thereby dehumidifying it. The cooling water W supplied from the water supply unit 41 into the exhaust duct 21, along with the dehumidified water generated in the exhaust duct 21 by the cooling water W, is discharged outside the machine, for example, by the drainage mechanism 16.

[0028] When the second dehumidification mechanism 50 is an air exchange type dehumidification mechanism, the second dehumidification mechanism 50 can be configured, as shown in Figures 1 and 4, for example, by having an exchange path 51, an opening / closing member 52, and a drive unit 53. The exchange path 51 is provided in the middle of the circulating air passage 20 and is an air path that connects the circulating air passage 20 with the outside. The exchange path 51 is configured to allow the warm air passing through the circulating air passage 20 and the outside air, that is, the air outside the outer box 11, to enter and exit, i.e., to be exchanged. The exchange path 51 can be provided on the upstream side of the heating chamber 22, i.e., on the inlet side of the heating chamber 22. The outside air can flow into the heating chamber 22 from the exchange path 51.

[0029] The opening / closing member 52 is configured to open and close the exchange path 51 and can be made of a damper, for example. The drive unit 53 is an electrical actuator for operating the opening / closing member 52 and can be made of a motor, solenoid, or the like. As shown in Figures 1 and 2, when the opening / closing member 52 is closed, the exchange path 51 is closed and not in communication with the outside. Therefore, there is no active exchange of air between the circulating air passage 20 and the outside air, i.e., the air outside the outer casing 11. In other words, when the opening / closing member 52 is closed, dehumidification by the second dehumidification mechanism 50 is not performed. On the other hand, as shown in Figure 3, when the opening / closing member 52 is open, the exchange path 51 is open and in communication with the outside. Therefore, when the opening / closing member 52 is open, there is an active exchange of air between the circulating air passage 20 and the outside air, i.e., the air outside the outer casing 11.

[0030] Furthermore, as shown in Figures 1 and 4, the washing machine 10 is equipped with a plurality of temperature sensors 18 and 19. Each temperature sensor 18 and 19 is capable of detecting temperatures related to the drying operation. Temperatures related to the drying operation refer to the temperatures of parts of the washing machine 10 that change under the influence of the drying operation. In the washing machine 10, the temperatures of the outer tub 12 and the circulating air passage 20 change under the influence of the drying operation. Therefore, in this embodiment, the washing machine 10 is equipped with, for example, an outer tub temperature sensor 18 and an air passage temperature sensor 19. The outer tub temperature sensor 18 is provided on the outer surface of the outer tub 12 and detects the temperature of the outer surface of the outer tub 12. The temperature of the outer surface of the outer tub 12 detected by the outer tub temperature sensor 18 correlates with the temperature inside the outer tub 12. The air passage temperature sensor 19 is provided in the circulating air passage 20 near the downstream side of the heating device 33 and detects the temperature of the air immediately after it has been heated by the heating device 33.

[0031] As shown in Figure 4, the washer-dryer 10 is equipped with a control device 60. The control device 60 mainly consists of a microcomputer having a CPU 601, a storage area 602 such as ROM, RAM, and non-volatile memory, and a timer 603 capable of measuring time. The control device 60 has the function of managing the operation of the entire washer-dryer 10. The motor 14, drain valve 161, water supply valve 17, temperature sensors 18 and 19, blower 32, heating device 33, dehumidification valve 42, and drive unit 53 are electrically connected to the control device 60 and operate based on control from the control device 60.

[0032] The control device 60 is capable of performing a drying operation. The drying operation is an operation in which clothes are dried by driving the blower 32 and the heating device 33 to supply hot air into the drying chamber, which consists of the outer tank 12 and the rotating tank 13. In addition, during normal drying operation, the control device 60 is capable of performing a first dehumidification process using the first dehumidification mechanism 40 and a second dehumidification process using the second dehumidification mechanism 50.

[0033] Here, "during normal drying operation" means, for example, drying operation when there is no abnormality in the washing machine 10, and especially when there is no abnormality in the first dehumidification mechanism 40 and the second dehumidification mechanism 50. In this embodiment, the first dehumidification process is the process of opening the dehumidification valve 42 and supplying cooling water W from the water supply unit 41 into the exhaust duct 21, as shown in Figure 2. The second dehumidification process is the process of opening the exchange path 51 by operating the opening / closing member 52, as shown in Figure 3.

[0034] The control device 60 can perform a first dehumidification process and a second dehumidification process during the drying operation, for example, as shown in Figure 5 or Figure 6. Graph (a) in Figures 5 and 6 shows the changes in input values ​​to the heating device 33 during the drying operation. Graph (b) in Figures 5 and 6 shows the changes in temperature during the drying operation. In graph (b), A1 shows the temperature of the outer surface of the outer tank 12, i.e., the measured value of the outer tank temperature sensor 18. Also, in graph (b), A2 shows the temperature immediately after the heating device 33 in the circulating air passage 20, i.e., the changes in the measured value of the air passage temperature sensor 19.

[0035] Furthermore, graph (c) in Figures 5 and 6 shows the change in the rotation speed of the blower 32 during drying operation. In this case, the rotation speed of the blower 32 correlates with the amount of air flowing through the circulating air passage 20. Graph (d) in Figures 5 and 6 shows the change in the operating status of the first dehumidification mechanism 40 during drying operation. And graph (e) in Figures 5 and 6 shows the change in the operating status of the second dehumidification mechanism 50 during drying operation.

[0036] Furthermore, the drying operation progresses in the following order: heating period T1, constant rate period T2, decay rate period T3, finishing period T4, and cooling period T5. The heating period T1 is the period from when the drying operation is started by driving the heating device 33 and the blower 32 until the temperature of the outer tank 12 tends to increase. The control device 60 can determine that the current period is the heating period T1, for example, when the temperature detected by the outer tank temperature sensor 18 is on an increasing trend. The control device 60 can also infer that the current period is the heating period T1 based on the elapsed time since the start of the drying operation.

[0037] The constant rate period T2 is the period during which the amount of moisture evaporating from the clothes in the outer tub 12 remains constant. When transitioning from the heating period T1 to the constant rate period T2, the temperature rise of the outer tub 12 stops and begins to stabilize, as shown by arrow B1. The control device 60 can determine that a transition has occurred from the heating period T1 to the constant rate period T2, for example, when the temperature detected by the outer tub temperature sensor 18 changes from an increasing trend to a constant trend. The control device 60 can also infer that a transition has occurred from the heating period T1 to the constant rate period T2 based on the elapsed time since the start of the drying operation.

[0038] The decay period T3 is the period during which the amount of moisture evaporating from the clothes in the outer tub 12 tends to decrease. When transitioning from the constant rate period T2 to the decay period T3, as shown by arrow B2, the temperature immediately after the heating device 33 drops slightly and then maintains a constant trend. The control device 60 can determine that the transition has occurred from the constant rate period T2 to the decay period T3 if, for example, it detects that the temperature detected by the airflow temperature sensor 19 has dropped slightly after transitioning to the constant rate period T2. The control device 60 can also infer that the transition has occurred from the constant rate period T2 to the decay period T3 based on the elapsed time since the start of the drying operation or the elapsed time since transitioning to the constant rate period T2.

[0039] The finishing period T4 is the period during which the garments are finished by reducing the heating by the heating device 33 and the airflow of the blower 32. At the end of the reduction period T3, the temperature of the outer tub 12 rises slightly, as shown in the area indicated by arrow B3. After transitioning to the reduction period T3, the control device 60 determines that the reduction period T3 has ended, for example, when it detects that the temperature detected by the outer tub temperature sensor 18 has risen slightly, and then transitions to the finishing period T4. Alternatively, the control device 60 may infer that the reduction period T3 has ended, for example, when a predetermined period has elapsed since transitioning to the reduction period T3, and then transitions to the finishing period T4.

[0040] The cooling period T5 is the period during which the temperature of the clothes in the outer tub 12 is lowered by stopping the heating device 33 while continuing to blow air from the blower 32. After transitioning to the cooling period T5, the control device 60 determines that the cooling period T5 has ended when it detects, for example, that the temperature detected by the outer tub temperature sensor 18 or the air passage temperature sensor 19 has dropped to a predetermined temperature, and stops the blower 32 to end the drying operation. Alternatively, the control device 60 may infer that the cooling period T5 has ended when, for example, a predetermined period has elapsed since transitioning to the cooling period T5, and stops the blower 32 to end the drying operation.

[0041] Furthermore, as shown in Figures 5 and 6, the control device 60 can operate the first dehumidification mechanism 40 to perform the first dehumidification process during the drying operation, and then operate the second dehumidification mechanism 50 to perform the second dehumidification process. In other words, the first dehumidification process is performed before the second dehumidification process. In Figures 5 and 6, the period during which the first dehumidification process is performed is shown as the first dehumidification period S1, and the period during which the second dehumidification process is performed is shown as the second dehumidification period S2. The control device 60 can perform the first dehumidification process during the constant rate period T2, and can perform the second dehumidification process during the decay rate period T3. The control device 60 does not perform either the first or second dehumidification process during the heating period T1.

[0042] In the example shown in Figure 5, the control device 60 controls the first dehumidification process and the second dehumidification process so that they do not run during overlapping periods. That is, in the example shown in Figure 5, the control device 60 prohibits the simultaneous execution of the first dehumidification process and the second dehumidification process, and controls the first dehumidification mechanism 40 and the second dehumidification mechanism 50 so that the first dehumidification period S1 and the second dehumidification period S2 do not overlap. In this case, the first dehumidification period S1 can be, for example, a period that coincides with the constant rate period T2. The second dehumidification period S2 can be, for example, a period that includes at least the decay rate period T3. In this embodiment, the second dehumidification period S2 coincides with the combined period of the decay rate period T3, the finishing period T4, and the cooling period T5.

[0043] In the example shown in Figure 6, the control device 60 executes the first dehumidification process and the second dehumidification process during an overlapping period. That is, in the example shown in Figure 6, the control device 60 can execute the first dehumidification process and the second dehumidification process simultaneously, and can control the first dehumidification mechanism 40 and the second dehumidification mechanism 50 so that the first dehumidification period S1 and the second dehumidification period S2 temporarily overlap. In the example shown in Figure 6, the control device 60 executes the first dehumidification process from the constant rate period T2 to the beginning of the decay rate period T3, and executes the second dehumidification process from the latter half of the constant rate period T2 to the decay rate period T3. Therefore, the first dehumidification period S1 and the second dehumidification period S2 overlap in the period before and after the transition from the constant rate period T2 to the decay rate period T3.

[0044] The control device 60 can execute or terminate the first dehumidification process and the second dehumidification process based on the temperature related to the drying operation, in this case, the temperature detected by the outer tank temperature sensor 18 or the airflow path temperature sensor 19. That is, the control device 60 can operate and stop the first dehumidification mechanism 40 and the second dehumidification mechanism 50 based on the temperature detected by the outer tank temperature sensor 18 or the airflow path temperature sensor 19.

[0045] Furthermore, the control device 60 can execute or terminate the first dehumidification process and the second dehumidification process based on the elapsed time from a reference time during the drying operation. That is, the control device 60 can operate and stop the first dehumidification mechanism 40 and the second dehumidification mechanism 50 based on the elapsed time from a reference time during the drying operation. The reference time can be set, for example, to the start of the drying operation, the time when the system transitions from the first dehumidification period S1 to the second dehumidification period S2, or the time when the system transitions from the constant rate period T2 to the decay rate period T3.

[0046] In the examples shown in Figures 5 and 6, the control device 60 can start the first dehumidification process when it detects, for example, that the heating period T1 has transitioned to the constant rate period T2 based on the temperature detected by the outer tank temperature sensor 18. The control device 60 can also start the first dehumidification process when a predetermined time has elapsed from, for example, the start time of the drying operation.

[0047] Furthermore, in the example shown in Figure 5, the control device 60 can terminate the first dehumidification process and start the second dehumidification process when it detects, for example, that the process has transitioned from the constant rate period T2 to the decay rate period T3 based on the temperature detected by the airflow temperature sensor 19. In addition, the control device 60 can terminate the first dehumidification process and start the second dehumidification process when a predetermined time has elapsed from, for example, the start of the drying operation or the transition from the heating period T1 to the constant rate period T2, using that reference time as the reference time.

[0048] Furthermore, in the example in Figure 6, the control device 60 can start the second dehumidification process after a predetermined time has elapsed from a reference time, such as the start of the drying operation or the transition from the heating period T1 to the constant rate period T2. Also, in the example in Figure 6, the control device 60 can terminate the first dehumidification process after a predetermined time has elapsed from a reference time, such as the start of the drying operation, the transition from the heating period T1 to the constant rate period T2, the start of the second dehumidification process, or the transition from the constant rate period T2 to the decay period T3. And, in the examples in Figures 5 and 6, the control device 60 can terminate the second dehumidification process upon the termination of the drying operation.

[0049] According to the embodiment described above, a washing machine / dryer 10, which is an example of a clothes dryer, comprises an outer tub 12 and a rotating tub 13, a circulating air passage 20, a heating device 33, a first dehumidification mechanism 40, a second dehumidification mechanism 50, and a control device 60. The outer tub 12 and the rotating tub 13 constitute a drying chamber capable of holding clothes. The circulating air passage 20 has the function of returning at least a portion of the air that has flowed out of the outer tub 12 to the outer tub 12. The heating device 33 has the function of heating the air passing through the circulating air passage 20. The first dehumidification mechanism 40 has the function of dehumidifying the air in the circulating air passage 20. The second dehumidification mechanism 50 has the function of dehumidifying the air in the circulating air passage 20 in a manner different from that of the first dehumidification mechanism 40. The control device 60 can drive the heating device 33 to perform a drying operation to dry the clothes in the outer tub 12. Furthermore, the control device 60 is capable of performing a first dehumidification process using the first dehumidification mechanism 40 and a second dehumidification process using the second dehumidification mechanism 50 during the drying operation.

[0050] According to this, the washing machine 10 is equipped with multiple dehumidification mechanisms 40 and 50, each employing a different dehumidification method. The control device 60 can dehumidify the air in the circulating air passage 20 during the drying operation using the dehumidification mechanism 40 or 50 appropriate to the current conditions. As a result, improvements can be made to the dehumidification of the hot air during the drying operation, enabling a more effective drying operation.

[0051] The first dehumidification mechanism 40 uses a water-cooling method, which involves supplying cooling water W into the circulating air passage 20 to cool and dehumidify the air within the circulating air passage 20. The second dehumidification mechanism 50 uses an air exchange method, which involves exchanging the air within the circulating air passage 20 with outside air to dehumidify the air within the circulating air passage 20.

[0052] Here, the first dehumidification mechanism 40, which employs a water-cooling system, is less economical than the second dehumidification mechanism 50, which employs an air-exchange system, because it uses water for dehumidification. However, it is more efficient at dehumidification and does not exhaust hot air to the outside, thus suppressing the rise in the ambient temperature of the washing machine 10. In contrast, the second dehumidification mechanism 50, which employs an air-exchange system, exhausts a portion of the hot air in the circulating air passage 20. Therefore, the ambient temperature of the washing machine 10 tends to rise more easily compared to the first dehumidification mechanism 40, which employs a water-cooling system. However, it is more economical because it does not use water for dehumidification.

[0053] Thus, this embodiment makes it possible to obtain the advantages of both by using the first dehumidification mechanism 40 and the second dehumidification mechanism 50, which have different characteristics, and as a result, further improvements can be made regarding the dehumidification of warm air during drying operation.

[0054] Here, the constant rate period T2 is the period during which the moisture content in the clothes decreases almost linearly due to heat exchange between the thermal energy stored in the heating period T1 and the moisture content in the clothes, and is the period with the highest dehumidification efficiency in the entire drying operation. Therefore, the amount of moisture contained in the warm air exhausted from the outer tub 12 is also high during the constant rate period T2. Accordingly, in this embodiment, the control device 60 is configured to perform a first dehumidification process using a water-cooled first dehumidification mechanism 40 during the constant rate period T2. As a result, according to this embodiment, by performing water-cooled dehumidification during the constant rate period T2 when humidity is high, dehumidification can be performed with high efficiency.

[0055] Here, after some time has elapsed since the start of the first dehumidification process using water cooling, the cooling water W supplied into the circulating air passage 20 by the first dehumidification mechanism 40 is heated by heat exchange with the warm air in the circulating air passage 20. As the drying operation progresses and approaches the decay period T3, the temperature difference between the cooling water W and the warm air decreases, and the dehumidification efficiency by the cooling water W decreases.

[0056] Therefore, in this embodiment, the control device 60 can perform a second dehumidification process using a second dehumidification mechanism 50 that employs a different dehumidification method from the first dehumidification mechanism 40, in this case an air exchange method, during the reduction period T3. As a result, the second dehumidification process by the second dehumidification mechanism 50 can compensate for the decrease in dehumidification efficiency by the first dehumidification mechanism 40. Consequently, according to this embodiment, high dehumidification efficiency can be obtained over a long period of drying operation, and as a result, the efficiency of the drying operation can be improved.

[0057] Furthermore, in this embodiment, the warm air discharged to the outside by the second dehumidification treatment during the rate reduction period T3 has had its humidity reduced to some extent by the first dehumidification treatment performed during the constant rate period T2 prior to the second dehumidification treatment. Therefore, even when the second dehumidification treatment is performed by air exchange, it is possible to suppress the increase in ambient humidity around the washing machine / dryer 10, which can easily lead to condensation.

[0058] The control device 60 controls the first dehumidification process and the second dehumidification process so as not to be performed during an overlapping period, as shown in Figure 5, for example. This prevents the temperature inside the circulating air passage 20 from dropping excessively due to the first and second dehumidification processes being performed during an overlapping period.

[0059] Furthermore, the control device 60 can perform the first dehumidification process and the second dehumidification process during an overlapping period, as shown in Figure 6, for example. By performing the first dehumidification process and the second dehumidification process during an overlapping period, the control device 60 can dehumidify the warm air in the circulating air passage 20 more efficiently and suppress the excessive rise of the warm air in the circulating air passage 20.

[0060] Furthermore, the control device 60 can start or end the first and second dehumidification processes based on temperatures related to the drying operation, such as the temperature of the outer surface of the outer tank 12 or the temperature inside the circulating air passage 20. As a result, the control device 60 can execute and end the first and second dehumidification processes at appropriate times according to the progress of the drying operation, thereby enabling efficient and waste-free dehumidification.

[0061] Furthermore, the control device 60 can start or end the first dehumidification process and the second dehumidification process based on the elapsed time from a reference point during the drying operation. As a result, the control device 60 can uniformly start and end the first dehumidification process and the second dehumidification process based on the elapsed time from a reference point, regardless of the progress of the drying operation, thus simplifying the control process.

[0062] Although one embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0063] 10...Washing machine (clothes dryer), 12...Outer tub (drying chamber), 13...Rotating tub (drying chamber), 20...Circulating air passage, 33...Heating device, 40...Dehumidification mechanism, 40...First dehumidification mechanism, 50...Second dehumidification mechanism, 60...Control device, T2...Constant rate period, T3...Decreasing rate period

Claims

1. A drying room capable of accommodating clothing, A circulation air passage that returns at least a portion of the air that flows out of the drying chamber back to the drying chamber, A heating device for heating the air passing through the aforementioned circulating air passage, A first dehumidification mechanism for dehumidifying the air in the aforementioned circulating air passage, A second dehumidification mechanism that dehumidifies the air in the circulating air passage using a method different from that of the first dehumidification mechanism, A control device capable of performing a drying operation to dry the clothes in the drying chamber by driving the heating device, Equipped with, The dehumidification method of the first dehumidification mechanism is a water-cooled type, which cools and dehumidifies the air in the circulating air passage by supplying water into the circulating air passage. The dehumidification method of the second dehumidification mechanism is an air exchange type that dehumidifies the air in the circulating air passage by exchanging the air in the circulating air passage with outside air. The first dehumidification mechanism and the second dehumidification mechanism are positioned such that air flowing out of the drying chamber into the circulating air passage passes through the first dehumidification mechanism and the second dehumidification mechanism and flows back into the drying chamber. The second dehumidification mechanism has an exchange path that connects the outside and inside of the circulating air passage and discharges a portion of the warm air passing through the circulating air passage to the outside of the circulating air passage. The control device is capable of performing a first dehumidification process using the first dehumidification mechanism and a second dehumidification process using the second dehumidification mechanism during the drying operation, and performs the first dehumidification process before the second dehumidification process and finishes the second dehumidification process after the first dehumidification process is completed. Clothes dryer.

2. The control device is capable of performing the first dehumidification process during a constant rate period in which the amount of moisture evaporating from the clothes in the drying chamber remains constant, and is capable of performing the second dehumidification process during a decrease rate period in which the amount of moisture evaporating from the clothes in the drying chamber tends to decrease. A clothes dryer according to claim 1.

3. The control device controls the first dehumidification process and the second dehumidification process so as not to be performed during overlapping periods. A clothes dryer according to claim 1.

4. The control device is capable of executing the first dehumidification process and the second dehumidification process during an overlapping period. A clothes dryer according to claim 1.

5. The system further includes a temperature sensor capable of detecting the temperature of a part that changes under the influence of the drying operation, as the temperature related to the drying operation. The control device can start or stop the first dehumidification process and the second dehumidification process based on the temperature related to the drying operation. A clothes dryer according to any one of claims 1 to 4.

6. It also features a timer capable of measuring time, The control device can start or end the first dehumidification process and the second dehumidification process based on a preset time elapsed from a reference time during the drying operation. A clothes dryer according to any one of claims 1 to 4.

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