EP2796615B1

EP2796615B1 - Clothes dryer and method of cleaning evaporator in clothes dryer

Info

Publication number: EP2796615B1
Application number: EP12859915.6A
Authority: EP
Inventors: Mitsuyuki Furubayashi; Masahiro Kawai; Mikio Tahara; Norihiko Fujiwara
Original assignee: Panasonic Corp
Current assignee: Panasonic Corp
Priority date: 2011-12-20
Filing date: 2012-12-11
Publication date: 2019-04-10
Anticipated expiration: 2032-12-11
Also published as: WO2013094150A1; EP2796615A1; CN104011286A; JPWO2013094150A1; EP2796615A4; JP5942098B2; CN104011286B

Description

TECHNICAL FIELD

The present invention relates to a clothes dryer drying an article to be dried, such as clothes, and a method of cleaning an evaporator in the clothes dryer.

BACKGROUND ART

In a conventional clothes dryer which mounts a heat pump device thereon, lint caused from a fiber product, such as clothes, is mixed into drying air. The mixed lint adheres and accumulates onto an air blower and a heat exchanger provided in a circulation air passage. As a result, the lint lowers a function of the air blower and the heat exchanger. Therefore, the conventional clothes dryer has, in the circulation air passage, a lint filter collecting the lint mixed into the drying air.
However, since the drying air flowing in the circulation air passage is required to ensure a fixed amount of air blown, a mesh of the lint filter cannot be made finer. Consequently, it is difficult for the lint filter to completely remove the lint from the drying air passing therethrough. As a result, the lint which passes through the lint filter adheres onto the heat exchanger to lower the function of the heat exchanger. Therefore, the conventional clothes dryer having a washing function washes away the lint adherent onto the heat exchanger with tap water (for instance, see Patent Literature 1).
Hereinafter, a configuration of the conventional clothes dryer described in Patent Literature 1 will be described with reference to FIG. 8.
FIG. 8 is a block diagram of the conventional clothes dryer having a washing function.
As shown in FIG. 8, the conventional clothes dryer having a washing function includes at least drum 52, outer tub 53, circulation air passage 60, and heat pump device 59. Drum 52 is rotatably provided in outer tub 53, and accommodates therein an article to be dried, such as clothes 51, to be rotatably driven. The clothes dryer supplies water into outer tub 53 via water supply valve 64, drains the water from the outer tub 53, and controls rotation of drum 52 to execute washing, rinsing, spin-drying, and drying steps.
To circulate a refrigerant, heat pump device 59 includes compressor 54, condenser 55, expansion device 56, and evaporator 57 connected with pipe 58. Condenser 55 and evaporator 57 in heat pump device 59 are disposed in circulation air passage 60 through which drying air is circulated.
Exhaust port 61 is provided in an upper front of outer tub 53. Air blow port 62 is provided in an upper portion of a rear surface of outer tub 53. Circulation air passage 60 connects exhaust port 61 and air blow port 62. Circulation air passage 60 has an inlet which flows the drying air thereinto and communicates with exhaust port 61, and an outlet which communicates with air blow port 62.
Air blower 63 is provided in circulation air passage 60 between condenser 55 in heat pump device 59 and air blow port 62, and blows the drying air.
A drying operation of the conventional clothes dryer having a washing function will be described below.
The drying operation is started to operate compressor 54 in heat pump device 59 and air blower 63 that blows the drying air into circulation air passage 60. The drying air is blown from air blow port 62 in circulation air passage 60 into drum 52. The drying air which is blown into drum 52 comes into contact with clothes 51 therein, and then takes the water from clothes 51 for drying.
Thereafter, the drying air which takes the water from clothes 51 to have high humidity flows from exhaust port 61 into circulation air passage 60. The high-humidity drying air is cooled by evaporator 57 in heat pump device 59 to be deprived of latent heat, and is then condensed to be dehumidified. The dehumidified drying air has lowered absolute humidity to be dried. The drying air is heated again by condenser 55 in heat pump device 59 to become dry hot air which is then blown from air blow port 62 into drum 52.
That is, the drying air blown from air blower 63 is circulated through circulation air passage 60 into drum 52 to execute the drying operation for clothes 51.
In the drying step, lint separated from clothes 51 in drum 52 is mixed into the drying air circulated in circulation air passage 60. The mixed lint adheres onto evaporator 57 to cause clogging between fins (not shown) of evaporator 57. As a result, the amount of the drying air flowing in circulation air passage 60 is reduced to lower heat exchange efficiency of heat pump device 59.
As shown in FIG. 8, the conventional clothes dryer having a washing function has cleaning unit 65 that opens openable and closable water supply valve 64 to inject a water solution for cleaning a heat exchanger to evaporator 57 and condenser 55 as the heat exchanger. Cleaning unit 65 injects the water solution for cleaning the heat exchanger to remove the lint adherent onto evaporator 57 and condenser 55.
As the water solution for cleaning the heat exchanger, tap water is used. In addition, the lint is removed with the condensed water generated on evaporator 57.
However, the conventional clothes dryer having a washing function removes the lint with the tap water injected from cleaning unit 65 to clean the heat exchanger. Therefore, when the tap water adherent onto the heat exchanger is evaporated, a scale component included therein remains as an evaporation residue on a surface of the heat exchanger. As a result, heat exchange efficiency of evaporator 57 and condenser 55 configuring the heat exchanger is lowered. The scale or scale component means a calcium or magnesium component contained in the water, such as the tap water, which is precipitated and deposited as an oxide, sulfide, carbonate, and carbohydrate. Ditto with the below.
In addition, when dried, the lint adherent onto evaporator 57 is fixed onto a surface of evaporator 57. Consequently, it is difficult to remove the lint fixed with the condensed water generated on the evaporator.
DE 10 2006 018 469 A1 describes a cloth drier which comprises an electric control with a program for controlling a pump and/or a component for opening and closing of a water flow pipeline, a heat pump system, a drum motor, an aerator, a condenser, a compressor, an evaporator, a drip device for condensation, and replaceable or cleanable water filters arranged behind a cover or flap for flooding, sprinkling, perfusion and/or over flow of the evaporators and/or compressors. The drying is carried out by dehydration of air promoted in air circulation operation through condensation by a cooler. The cloth drier comprises an electric control with a program for controlling a pump and/or a component for opening and closing of a water flow pipeline, a heat pump system, a drum motor, an aerator, a condenser, a compressor, an evaporator, a drip device for condensation, and replaceable or cleanable water filters arranged behind a cover or flap for flooding, sprinkling, perfusion and/or over flow of the evaporators and/or compressors. The drying is carried out by dehydration of air promoted in air circulation operation through condensation by a cooler, which is a part of the heat pump system. In accordance with the program, the water is flowable into a collection tank located on heat exchanger or its partial area for balancing temperature and pressure in the heat pump system. The filter is present in the conveying cycle of the water pump. An installation for monitoring the filters is available, by which the drier can be recognized, when the filter is subjected and must be cleaned. A procedure for the usage of the cloth drier is also described.
EP 1 541 745 A1 describes a clothes drying apparatus which includes a heat pump mechanism, an air path for guiding drying air into a drying drum accommodating therein clothes, a blower for supplying drying air to the air path, and a controller for controlling a driving of a compressor, wherein the controller operates the blower and the compressor during a drying operation; stops the compressor in case the drying operation is suspended; and operates, in case the drying operation is resumed, the compressor after a certain time period has elapsed since the compressor had stopped. In case employing the heat pump mechanism having the compressor as a heat source, it is possible to reduce a load on the compressor and allow temperature of warm air to rapidly return by using the heat pump mechanism.
EP 2 037 035 A1 describes a laundry treatment device having a drying program and a control method thereof, wherein the laundry treatment device comprises a water tub, a rotatable drum disposed inside the water tub, a heating assembly for heating air into dry hot air, a condensing assembly for condensing moisture contained in relatively humid hot air, and a blowing device for driving an air circulation, wherein an air circulating loop is formed among the heating assembly, water tub, drum, condensing assembly and blowing device, and a spraying device for flushing the fluff accumulated on the condensing assembly is disposed between the condensing assembly and the blowing device. The water is sprayed from top down to the condensing assembly by the spraying device, thereby flushing away the fluff accumulated on the condensing assembly.
DE 10 2007 052 835 A1 relates to a method and device for cleaning an evaporator of a condenser which is arranged within a process air cycle of a washer or dryer. In this respect, it is described that condensate which is recovered in the process air cycle from the dryer of wet laundry and collected in a condensate water tank is provided to an above evaporator rinsing container and delivered by suddenly opening the rinsing container or the rinsing chamber on the outlet side as a surge of water to the evaporator, and/or pressurized power water is delivered to the evaporator.

Citation List

Patent Literature

PTL 1: Unexamined Japanese Patent Publication No. 2005-224491
PTL 2: DE 10 2006 018 469 A1
PTL 3: EP 1 541 745 A1
PTL 4: EP 2 037 035 A1
PTL 5: DE 10 2007 052 835 A1

SUMMARY OF THE INVENTION

The invention is defined by the subject-matter of the independent claims.
The dependent claims are directed to advantageous embodiments.

ADVANTAGES OF THE INVENTION

Advantageously, a clothes dryer includes a drying chamber for accommodating therein an article to be dried, an air passage through which drying air discharged from the drying chamber is circulated into the drying chamber again, a heat pump device provided in the air passage and including a compressor, a condenser, an expansion device, and an evaporator connected with a pipe to circulate a refrigerant, an air blower for blowing the air into the air passage, a discharging unit for discharging water to the evaporator, and a controller for controlling a drying operation. The controller discharges the water from the discharging unit, and then operates the compressor.
With this, the dehumidified water generated on the evaporator during the drying operation can remove the water which removes lint. Therefore, the scale component contained in the water can be prevented from adhering onto the evaporator, to remove the lint. As a result, heat exchange efficiency of the evaporator configuring a heat exchanger in the heat pump device can be prevented from being lowered. The clothes dryer can thus stably maintain drying performance for a long period.
An advantageous method of cleaning an evaporator in a clothes dryer includes a first step of discharging water to the evaporator in a heat pump device to remove lint adherent onto the evaporator, a second step of operating a compressor to cool the evaporator, a third step of operating an air blower to blow drying air, and a fourth step of removing the water adherent onto the evaporator with dehumidified water generated on the evaporator.
With this, the water which removes the lint adherent onto the evaporator can be removed with the dehumidified water generated on the evaporator during the drying operation. Therefore, the scale component contained in the water can be prevented from adhering onto the evaporator, to remove the lint. As a result, heat exchange efficiency of the evaporator can be prevented from being lowered. The evaporator in the clothes dryer can thus be maintained with high performance and reliability for a long period.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a clothes dryer according to a first exemplary embodiment of the present invention.
FIG. 2 is a time chart showing an operation of the clothes dryer of the exemplary embodiment.
FIG. 3 is a flowchart of assistance in explaining an operation of the clothes dryer including a method of cleaning an evaporator in the clothes dryer of the exemplary embodiment.
FIG. 4A is a schematic diagram showing a flow of water continuously discharged from a discharging unit during lint removal according to the clothes dryer of the exemplary embodiment.
FIG. 4B is a schematic diagram showing a flow of water intermittently discharged from the discharging unit during lint removal according to the clothes dryer of the exemplary embodiment.
FIG. 5 is a time chart showing another operation of the clothes dryer of the exemplary embodiment.
FIG. 6A is a schematic diagram of a clothes dryer according to a a further embodiment not being part of the present invention during lint removal.
FIG. 6B is a schematic diagram of the clothes dryer of Fig. 6A during water removal.
FIG. 7 is a schematic diagram of a clothes dryer according to the present invention during lint removal.
FIG. 8 is a block diagram of a conventional clothes dryer.

DESCRIPTION OF EMBODIMENTS

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

(FIRST EXEMPLARY EMBODIMENT)

Hereinafter, a clothes dryer of a first exemplary embodiment of the present invention will be described with reference to FIG. 1.
FIG. 1 is a schematic diagram of the clothes dryer according to the first exemplary embodiment of the present invention.
As shown in FIG. 1, clothes dryer 1 of this exemplary embodiment includes heat pump device 7 having at least evaporator 5, drying chamber 9, air passage 10 through which drying air is circulated in a direction indicated by arrows A, air blower 8, discharging unit 13 discharging water to evaporator 5, and controller 16.
In heat pump device 7, compressor 2, condenser 3, expansion device 4, and evaporator 5 are connected with pipe 6 to circulate a refrigerant therebetween. Compressor 2 compresses the refrigerant. Condenser 3 releases heat of the high-temperature and high-pressure refrigerant compressed by compressor 2. Expansion device 4 includes e.g., a capillary tube and a valve to reduce a pressure of the high-pressure refrigerant. With the low-pressure refrigerant reduced in pressure by expansion device 4, evaporator 5 takes heat from e.g., the high-humidity drying air circulated in air passage 10 to dehumidify the drying air.
Condenser 3 and evaporator 5 in heat pump device 7 include a fin tube heat exchanger having e.g., a plurality of fins 5a. Pipe 6 is formed of e.g., a copper pipe, and flows the refrigerant therethrough. Pipe 6 extends through fins 5a. Fins 5a through which pipe 6 extends are parallel in air passage 10 with predetermined spacing. A channel for the drying air is formed of a gap between fins 5a. Fins 5a are each formed of an aluminum plate having e.g., a thickness of 0.08 mm to 0. 2 mm by e.g., punching. The fin tube heat exchanger is formed by arranging fins 5a through which pipe 6 extends, at a fin pitch of e.g., approximately 1. 2 mm.
As shown in FIG. 1, air passage 10 has therein evaporator 5 cooling and dehumidifying the drying air, condenser 3 heating the dehumidified low-temperature drying air, and air blower 8 sucking, exhausting, and blowing the drying air. Both ends of air passage 10 are annually connected to communicate with drying chamber 9 accommodating clothes 20 therein for circulating the drying air. Filter 11 is detachably attached to air passage 10 between drying chamber 9 and evaporator 5 communicating with each other. Filter 11 collects lint caused from clothes 20 during a drying operation.
Drain port 12 is provided below evaporator 5, and drains dehumidified water generated on evaporator 5 in the drying step. The dehumidified water generated on evaporator 5 is discharged from drain port 12 to an outside of clothes dyer 1.
As shown in FIG. 1, discharging unit 13 is provided above end face 5b of evaporator 5 on an upstream side of a flow of the drying air. Discharging unit 13 discharges the water, such as tap water, to evaporator 5. Water supply valve 15 provided in water supply path 14 is opened and closed to discharge and stop the water from discharging unit 13. The water is discharged from discharging unit 13 to end face 5b on an upwind side of evaporator 5, that is, on a side in which the drying air flowing in air passage 10 in the direction indicated by arrows A flows into evaporator 5. With this, the lint adherent onto evaporator 5 is removed. The water which is discharged from discharging unit 13 to remove the lint is discharged from drain port 12 to the outside of clothes dryer 1.
As shown in FIG. 1, controller 16 controls at least compressor 2 in heat pump device 7, air blower 8, and water supply valve 15 to control the drying operation of clothes dryer 1.
An operation of the clothes dryer and a method of cleaning the evaporator in the clothes dryer will be described below with reference to FIGS. 2 and 3.
FIG. 2 is a time chart showing the operation of the clothes dryer of the exemplary embodiment. FIG. 3 is a flowchart of assistance in explaining the clothes dryer including the method of cleaning the evaporator in the clothes dryer of the exemplary embodiment.
As shown in FIGS. 2 and 3, the operation of clothes dryer 1 is started (step S10).
Controller 16 intermittently opens and closes (on - off) water supply valve 15 during e.g., predetermined time 0 to T1 before start of the drying operation. During predetermined time 0 to T1, the water, such as the tap water, is intermittently discharged from discharging unit 13 to end face 5b of evaporator 5. With this, a first step of removing the lint fixed onto end face 5b of evaporator 5 with the water from discharging unit 13 is executed (step S20). The water which removes the lint is discharged from drain port 12 provided below evaporator 5 to the outside of clothes dryer 1.
The wording "before start of the drying operation" specifically means "before operation of compressor 2 in heat pump device 7 and air blower 8".
Predetermined time 0 to T1 is time corresponding to time to remove the lint adherent onto evaporator 5, and is set to e.g., 60 seconds. When the predetermined time is made longer, the drying time becomes longer, which is not convenient for the user. Therefore, the predetermined time is preferably set to approximately 15 seconds to 90 seconds.
As shown in FIGS. 2 and 3, after elapse of predetermined time T1, controller 16 operates compressor 2 in heat pump device 7 and air blower 8 to start the drying operation for an article to be dried, such as clothes 20, thrown into drying chamber 9. Compressor 2 in heat pump device 7 is operated to cool evaporator 5 for executing a second step (step S30). At the same time, air blower 8 is operated to blow the drying air in air passage 10 for executing a third step (step S40).
The drying air which is blown from air blower 8 to be circulated in air passage 10 passes through condenser 3 to be heated with heat released therefrom, and then becomes hot air to be sent into drying chamber 9. The drying air comes into contact with clothes 20 in drying chamber 9, and then takes the water from clothes 20 for drying. The drying air becomes high-humidity air by the water taken from clothes 20. The high-humidity drying air passes through evaporator 5 to be cooled. The drying air whose water vapor is condensed is dehumidified to form the dehumidified water. Therefore, the dehumidified water is formed to be clean without containing the scale component.
After start of the drying operation, the dehumidified water generated due to condensation on evaporator 5 is moved downward by its own weight along surfaces of fins 5a of evaporator 5. The dehumidified water is moved on the surface of evaporator 5 to remove the water adherent onto the surface of evaporator 5 in the first step. With this, a fourth step of removing the water with the dehumidified water is executed (step S50).
Thereafter, the dehumidified water which is moved downward to take in and remove the water is discharged from drain port 12 provided below evaporator 5 to the outside of clothes dryer 1.
The drying air which is dehumidified by evaporator 5 to have lowered absolute humidity is heated by condenser 3 again to be blown into drying chamber 9.
The second to fourth steps are repeated until the clothes is dried, for executing the drying operation (step S60).
From the above, the drying operation is executed.
During the drying operation for the clothes, in heat pump device 7, when controller 16 operates compressor 2, heat of the high-temperature and high-pressure refrigerant compressed by compressor 2 is released by condenser 3. The heat-released high-pressure refrigerant is reduced in pressure by expansion device 4 to have low pressure and low temperature. The low-pressure and low-temperature refrigerant takes heat from the drying air in evaporator 5 to return into compressor 2 again. That is, a heat amount obtained by adding a heat amount obtained from input power into compressor 2 to a heat amount taken by the low-temperature and low-pressure refrigerant in evaporator 5 is released from condenser 3. Therefore, heat energy released from condenser 3 into the drying air is substantially equal to the sum of the heat amount obtained from the input power into compressor 2 and the heat amount taken from the drying air in evaporator 5.
Condenser 3 can obtain an output (heat energy) above the input power inputted into compressor 2 to heat the drying air which can then be thrown into clothes 20 in drying chamber 9. With this, the drying air dehumidified in evaporator 5 and heated by the condenser is thrown into drying chamber 9, and comes into contact with clothes 20 for drying.
As the drying of clothes 20 proceeds, the lint is caused from clothes 20. The caused lint is mixed into the drying air, is conveyed to filter 11 by the circulated drying air, and is collected by filter 11.
However, to ensure a fixed amount of air blown and to prevent excessive power consumption, typically, a mesh of filter 11 cannot be made finer. Therefore, part of the lint can pass through filter 11 without being collected by filter 11. The lint which passes through filter 11 adheres onto end face 5b of evaporator 5 on the upstream side of the direction in which the drying air flows. In this exemplary embodiment, the fin pitch in evaporator 5 is e.g., approximately 1. 2 mm. Accordingly, the lint which passes through filter 11 adheres only onto end face 5b of evaporator 5.
After completion of the drying operation for the article to be dried, such as clothes 20, the lint adheres onto filter 11 and end face 5b of evaporator 5. In this case, the user can remove the lint adherent onto filter 11 by detaching detachable filter 11. However, the user cannot remove the lint adherent onto evaporator 5.
The amount of the lint adherent onto evaporator 5 is small at an early stage in which the number of drying operations is low. However, as the number of drying operations is increased, a large amount of lint adheres onto evaporator 5. Consequently, air passage pressure loss in evaporator 5 is gradually increased to gradually decrease the amount of the circulated drying air. As a result, drying performance of the clothes dryer is lowered with increase of the number of drying operations.
Therefore, as described with reference to FIGS. 2 and 3, in this exemplary embodiment, controller 16 intermittently opens and closes water supply valve 15 e.g., before start of the drying operation. During the predetermined time (e.g., 60 seconds, and opening time and closing time are substantially the same (or the same)), the water is intermittently discharged from discharging unit 13 to end face 5b of evaporator 5 onto which the lint is adherent. With this, the lint adherent onto evaporator 5 is removed.
The reason why the water is intermittently discharged from discharging unit 13 will be described below with reference to FIGS. 4A and 4B.
FIG. 4A is a schematic diagram showing a flow of the water continuously discharged from the discharging unit during lint removal according to the clothes dryer of the exemplary embodiment. FIG. 4B is a schematic diagram showing a flow of the water intermittently discharged from the discharging unit during lint removal according to the clothes dryer of the exemplary embodiment.
As shown in FIG. 4A, the lint is separated with the water continuously discharged from discharging unit 13, and is then collected to be a lump. In this state, the discharged water can flow so as to avoid the lump of the collected lint. In this case, as indicated by arrows B, the water continuously flows in such a manner as to avoid the lint lump. Consequently, the lint cannot be removed.
As shown in FIG. 4B, the water is intermittently discharged from discharging unit 13 to form the lint lump, as indicated by arrows C, and then is repeatedly collided therewith. Repeated collision of the intermittently discharged water with the lint lump can gradually separate the originally adherent lint and the separated-lint lump to remove the lint adherent onto evaporator 5.
As described above, in this exemplary embodiment, before start of the drying operation, the water, such as the tap water, is discharged from discharging unit 13 to remove the lint adherent onto evaporator 5. In this state, the water containing the scale component is adherent onto evaporator 5. Thereafter, the dehumidified water generated on evaporator 5 removes the water adherent onto evaporator 5. That is, before start of the drying operation, the water which removes the lint can be washed away and removed with the dehumidified water generated due to condensation on evaporator 5 during the drying operation. The water adherent onto evaporator 5 is removed with the dehumidified water before it is dried on the surface of evaporator 5. Therefore, the scale component contained in the water can be prevented from adhering and fixed onto evaporator 5, to remove the lint.
This can prevent clogging in evaporator 5 due to the lint and adhesion and accumulation of the scale component contained in the water. As a result, heat exchange efficiency of evaporator 5 can be prevented from being lowered to maintain high drying performance.
Another operation of the clothes dryer according to this exemplary embodiment and a method of cleaning the evaporator in the clothes dryer will be described below with reference to FIGS. 3 and 5.
FIG. 5 is a time chart showing another operation of the clothes dryer of the exemplary embodiment.
That is, the operation of the clothes dryer of this exemplary embodiment is different from the operation described with reference to FIG. 2 in that compressor 2 in heat pump device 7 is operated to operate air blower 8 after elapse of predetermined time. The operation of the clothes dryer will be specifically described.
As shown in FIG. 5, the operation of clothes dryer 1 is started (step S10).
Controller 16 intermittently opens and closes (on - off) water supply valve 15 during e.g., predetermined time 0 to T1 before start of the drying operation. During predetermined time 0 to T1, the water, such as the tap water, is intermittently discharged from discharging unit 13 to end face 5b of evaporator 5. With this, the first step of removing the lint fixed onto end face 5b of evaporator 5 with the water from discharging unit 13 is executed (step S20). The water which removes the lint is discharged from drain port 12 provided below evaporator 5 to the outside of clothes dryer 1.
The wording "before start of the drying operation" specifically means "before operation of compressor 2 in heat pump device 7 and air blower 8".
After the lint is removed from evaporator 5, controller 16 closes water supply valve 15 to stop water supply.
After elapse of predetermined time T2 from operation of compressor 2, controller 16 operates air blower 8 to start the drying operation. Predetermined time T1 to T2 is time from operation of compressor 2 to operation of air blower 8, and is set to e.g., 10 seconds. When predetermined time T1 to T2 is made longer, temperatures of compressor 2 and condenser 3 become higher to apply an excessive load to heat pump device 7. Therefore, predetermined time T1 to T2 is preferably set to approximately 5 seconds to 30 seconds which is time to prevent the excessive load even when compressor 2 is singly operated.
More specifically, a surface of evaporator 5 before start of the drying operation is wet with the water discharged for removing the lint from discharging unit 13. When compressor 2 is operated, evaporator 5 is cooled, so that the water adherent onto evaporator 5 is also cooled. After elapse of predetermined time T2 from operation of compressor 2, controller 16 operates air blower 8 to start the drying operation to dry the clothes.
With this, evaporator 5 is cooled with the refrigerant before the drying air is blown. The water adherent onto evaporator 5 is cooled to lower its temperature. The water is thus unlikely to be dried. In this state, when the drying of clothes 20 proceeds, the dehumidified water is condensed onto entire evaporator 5.
The dehumidified water generated due to condensation on evaporator 5 is moved downward by its own weight along surfaces of fins 5a of evaporator 5, and is then discharged from drain port 12 provided below evaporator 5 to the outside of clothes dryer 1. At this time, the water adherent onto evaporator 5 in a wet state is discharged together with the dehumidified water. With this, the water adherent onto evaporator 5 is removed with the dehumidified water. The scale can thus be prevented from adhering onto evaporator 5, the scale being caused in the water which removes the lint to be dried. As a result, lowered heat exchange efficiency due to adhesion of the scale contained in the water can be prevented. Even when used for a long period, the clothes dryer is unlikely to lower drying performance.

(SECOND EXEMPLARY EMBODIMENT)

Hereinafter, a clothes dryer according to a second exemplary embodiment that is not part of the present invention will be described with reference to FIGS. 6A and 6B.
FIG. 6A is a schematic diagram of the clothes dryer according to the second exemplary embodiment during lint removal. FIG. 6B is a schematic diagram of the clothes dryer of the exemplary embodiment during water removal.
As shown in FIGS. 6A and 6B, in the clothes dryer of this exemplary embodiment, water discharge area 17 discharging the water, such as the tap water, discharged from discharging unit 13 into evaporator 5 is equal to or smaller than water removal area 18 removing the water with the dehumidified water generated on evaporator 5 and to a part of evaporator 5. Other configurations are the same as the first exemplary embodiment. The same configurations are indicated by similar reference numerals, and the first exemplary embodiment is cited for the detailed description.
That is, discharging unit 13 removing the lint adherent onto evaporator 5 discharges the water to near end face 5b of evaporator 5. The dehumidified water which removes the water adherent onto evaporator 5 is generated on entire evaporator 5 to wash away the water from the surface of evaporator 5.
Specifically, water discharge area 17 shown in FIG. 6A and discharging the water from discharging unit 13 into evaporator 5 is equal to or smaller than water removal area 18 shown in FIG. 6B and removing the water with the dehumidified water generated on entire evaporator 5 and to a part of evaporator 5.
That is, water discharge area 17 is within water removal area 18. The water can thus be concentratively discharged to near end face 5b of evaporator 5 onto which a large amount of lint adheres. With this, the lint adherent onto evaporator 5 can be removed more certainly. In addition, the scale can be certainly prevented from adhering onto evaporator 5, the scale being caused in the water which remains after lint removal to be evaporated.

(THIRD EXEMPLARY EMBODIMENT)

Hereinafter, a clothes dryer according to the present invention will be described with reference to FIG. 7.
FIG. 7 is a schematic diagram of the clothes dryer according to the third exemplary embodiment of the present invention during lint removal.
As shown in FIG. 7, in the clothes dryer of this exemplary embodiment, discharging unit 13 is provided above a downstream side of end face 5b on the upstream side of evaporator 5 into which the drying air flows, and discharges the water to end face 5b on the upstream side of evaporator 5. Other configurations are the same as the first exemplary embodiment. The same configurations are indicated by similar reference numerals, and the first exemplary embodiment is cited for the detailed description.
That is, as shown in FIG. 7, discharging unit 13 is provided above the downstream side of evaporator 5 in the direction in which the drying air flows. Discharging unit 13 discharges the water to the lint adherent onto end face 5b of evaporator 5.
In this case, a direction of the water discharged from discharging unit 13 is opposite to the direction in which the drying air flows. With this, the water can be discharged from the substantially opposite direction of a direction in which the lint adheres (or from an interior of evaporator 5). As a result, the water can be discharged from the interior of evaporator 5 to effectively pullably separate the lint adherent onto the end face 5b of evaporator 5 to outside.
In addition, the lint can be pullably separated so as to be pushed out with the water to the upstream side of evaporator 5. The lint can be separated more easily than when the water is vertically discharged to pullably separate the lint. With this, the lint lump is unlikely to be caused. As a result, the lint can be easily removed even when a pressure of the water is low.
In each of the exemplary embodiments, as the water removing the lint adherent onto evaporator 5, the tap water is used. However, the present invention is not limited to this. For instance, the water may be filtered bath water and well water, and water which washes away the lint and is dried on the surface of evaporator 5 to leave the scale. In this case, the same effect as the exemplary embodiments can be obtained.
In each of the exemplary embodiments, the pressure of the water, such as the tap water, supplied from outside through water supply path 14 discharges the water from the discharging unit 13 to remove the lint. However, the present invention is not limited to this. For instance, a discharging pump may be provided ahead of discharging unit 13 to pressurize and discharge the water. With this, even in a place in which the pressure of the water, such as the tap water, is low, sufficient lint removal performance can be ensured. Further, when there is no water supply equipment outside, a water supply tank and a discharging pump are provided, the water supply tank storing therein the water, such as the tap water, and the discharging pump discharging the water in the water supply tank. The water supply tank and the discharging pump may be combined together with the water supply passage and the water supply valve of the exemplary embodiments to configure the clothes dryer. With this, a selection area of a place for use can be widened to enhance general-purpose properties.
In each of the exemplary embodiments, the water is intermittently discharged from the discharging unit. However, the present invention is not limited to this. For instance, high-pressure water may be continuously discharged.
In each of the exemplary embodiments, the on and off periods during intermittent discharge of the water are the same. However, the present invention is not limited to this. The on and off periods may be optional.
In each of the exemplary embodiments, the fin pitch in evaporator 5 is approximately 1.2 mm. However, the present invention is not limited to this. For instance, the fin pitch may be made narrower to configure evaporator 5. With this, the lint can adhere onto end face 5b of evaporator 5 more certainly. As a result, the lint can be easily removed. However, when the fin pitch is made narrower, air passage pressure loss in the drying air which passes through the channel of evaporator 5 is increased. Therefore, the fin pitch is preferably set to a value in which a balance between lint removal and air passage pressure loss is optimum.
In each of the exemplary embodiments, the present invention has been described by taking the clothes dryer as an example. However, the present invention is not limited to this. For instance, the present invention may be a washer dryer having a washing function and performing washing and drying. The same effect can be obtained.
As described above, the clothes dryer of the present invention includes a drying chamber for accommodating therein an article to be dried;an air passage through which drying air discharged from the drying chamber is circulated into the drying chamber again;a heat pump device provided in the air passage and including a compressor, a condenser, an expansion device, and an evaporator connecting with a pipe to circulate a refrigerant;an air blower for blowing air into the air passage;a discharging unit for discharging water to the evaporator; anda controller for controlling a drying operation,wherein the controller is configured to control a water supply valve to supply the water to the discharging unit, and to operate the compressor to cool the evaporator after discharging the water to the evaporator;wherein after elapse of a predetermined time from operation of the compressor, the controller operates the air blower;wherein water generated on the evaporator during the drying operation removes the water which is discharged and adhered onto the evaporator, wherein said water which is discharged from the discharging unit is any one of a tap water, bath water and well water; the clothes dryer further comprising:a drain port provided below the evaporator and configured to discharge the water generated on the evaporator and the water discharged from the discharging unit to an outside of the clothes dryer;wherein the discharging unit is provided above a downwind side of an end face on an upwind side of the evaporator, said upwind side being a side in which the drying air flows into the evaporator, said downwind side being opposite to the upwind side,wherein the discharging unit discharges the water to the end face on the upwind side of the evaporator from above the evaporator,wherein the discharging unit discharges the water to a lint adhered onto the end face of the evaporator,wherein the discharging unit discharges the water in a direction opposite to the direction in which the drying air flows.
With this, the dehumidified water generated on the evaporator during the drying operation can remove the water which removes the lint. Therefore, the scale component contained in the water can be prevented from adhering onto the evaporator, to remove the lint. As a result, heat exchange efficiency of the evaporator configuring the heat exchanger in the heat pump device can be prevented from being lowered. The clothes dryer can thus stably maintain drying performance for a long period.
According to the clothes dryer of the present invention, after elapse of the predetermined time from operation of the compressor, the controller operates the air blower. With this, the evaporator can be cooled by the refrigerant before the drying air is blown. Therefore, the water adherent onto the evaporator can be cooled to be unlikely to be dried. As a result, the water which removes the lint can be prevented from being evaporated, and can be removed with the dehumidified water generated on the evaporator.
According to the clothes dryer of the present invention, the controller intermittently discharges the water from the discharging unit. With this, when the lint separated with the discharged water is collected to be a lump, the water is repeatedly intermittently collided with the lint lump so that the lint can be separated more certainly. As a result, the lint adherent onto the evaporator can be removed more efficiently.
According to the clothes dryer of the present invention, the water discharge area of the discharging unit discharging the water to the evaporator is a part of the evaporator. With this, the water can be concentratively discharged to a portion of the evaporator onto which a large amount of lint adheres. The lint adherent onto the evaporator can thus be removed more efficiently. Further, the water adherent onto the wide area of the evaporator can be removed with the dehumidified water more certainly. As a result, the scale caused in the water which remains on the surface of the evaporator to be evaporated can be prevented from adhering onto the evaporator.
According to the clothes dryer of the present invention, the discharging unit is provided near the end face on the upstream side of the evaporator into which the drying air flows. With this, the water can be concentratively discharged to near the end face of the evaporator onto which a large amount of lint is likely to adhere.
According to the clothes dryer of the present invention, the discharging unit is provided at the downstream side of the end face on the upstream side of the evaporator into which the drying air flows, and the discharging unit discharges the water to the end face on the upstream side of the evaporator. With this, the water can be discharged onto the end face of the evaporator from the direction opposite to the side in which the lint flows to adhere. As a result, the water is discharged from the interior of the evaporator to effectively pullably separate the lint adherent onto the end face of the evaporator to the outside.
According to the clothes dryer of the present invention, the water is any one of the tap water, bath water, and well water. With this, the clothes dryer can be excellent in general-purpose properties.
The method of cleaning the evaporator in the clothes dryer of the present invention includes a drying chamber for accommodating therein an article to be dried;an air passage through which drying air discharged from the drying chamber is circulated into the drying chamber again; a heat pump device provided in the air passage and including a compressor, a condenser, an expansion device, and an evaporator connecting with a pipe to circulate a refrigerant;an air blower for blowing air into the passage; a discharging unit for discharging water to the evaporator; wherein the discharging unit is provided above a downwind side of an end face on an upwind side of the evaporator, said upwind side being a side in which the drying air flows into the evaporator, said downwind side being opposite to the upwind side; a controller for controlling a drying operation, wherein the controller controls a water supply valve to supply the water to the discharging unit, and operates the compressor to cool the evaporator after discharging the water to the evaporator; anda drain port provided below the evaporator for discharging the water generated on the evaporator and the water discharged from the discharging unit; the method comprising: a first step of discharging water to the evaporator in the heat pump device to remove lint adherent onto the evaporator, said water being any one of a tap water, bath water and well water; wherein in the first step the water is discharged to the end face on the upwind side of the evaporator from above the evaporator,wherein the water is discharged to the lint adhered onto the end face of the evaporator, wherein the water discharged from the discharging unit is discharged in a direction opposite to the direction in which the drying air flows; a second step of operating the compressor to cool the evaporator;a third step of operating the air blower to blow the drying air, wherein after elapse of a predetermined time from execution of the second step, the third step is executed; a fourth step of removing the water which is discharged and adhered to the evaporator with water which is generated on the evaporator during the drying process; and a step of discharging the water generated on the evaporator and the water discharged from the discharging unit to the outside of the clothes dryer. With the afore-mentioned four steps, the water which removes the lint adherent onto the evaporator can be removed with the dehumidified water generated on the evaporator during the drying operation. Therefore, the scale component contained in the water can be prevented from adhering onto the evaporator, to remove the lint. As a result, heat exchange efficiency of the evaporator can be prevented from being lowered. The evaporator in the clothes dryer can thus be maintained with high performance and reliability for a long period.
According to the method of cleaning the evaporator in the clothes dryer of the present invention, after elapse of the predetermined time from execution of the second step, the third step is executed. With this, the evaporator can be cooled by the refrigerant before the drying air is blown. Therefore, the water adherent onto the evaporator can be cooled to be unlikely to be dried. As a result, the water which removes the lint can be prevented from being evaporated, and can be removed with the dehumidified water generated on the evaporator.
According to the method of cleaning the evaporator in the clothes dryer of the present invention, the water is any one of the tap water, bath water, and well water. With this, the clothes dryer can be excellent in general-purpose properties.

INDUSTRIAL APPLICABILITY

The present invention is useful for the field of the clothes dryer in which the scale adheres onto the evaporator so that heat exchange efficiency is likely to be lowered.

REFERENCE MARKS IN THE DRAWINGS

1: clothes dryer
2, 54: compressor
3, 55: condenser
4, 56: expansion device
5, 57: evaporator
5a: fin
5b: end face
6, 58: pipe
7, 59: heat pump device
8, 63: air blower
9: drying chamber
10: air passage
11: filter
12: drain port
13: discharging unit
14: water supply path
15, 64: water supply valve
16: controller
17: water discharge area
18: water removal area
20, 51: clothes
52: drum
53: outer tub
60: circulation air passage
61: exhaust port
62: air blow port
65: cleaning unit

Claims

A clothes dryer (1) comprising:
a drying chamber (9) for accommodating therein an article (20) to be dried;

an air passage (10) through which drying air discharged from the drying chamber (9) is circulated into the drying chamber (9) again;

a heat pump device (7) provided in the air passage (10) and including a compressor (2), a condenser (3), an expansion device (4), and an evaporator (5) connecting with a pipe (6) to circulate a refrigerant;

an air blower (8) for blowing air into the air passage (10);

a discharging unit (13) for discharging water to the evaporator (5); and

a controller (16) for controlling a drying operation,

wherein the controller (16) is configured to control a water supply valve (15) to supply the water to the discharging unit (13), and to operate the compressor (2) to cool the evaporator (5) after discharging the water to the evaporator (5);

wherein after elapse of a predetermined time from operation of the compressor (2), the controller (16) operates the air blower (8);

wherein water generated on the evaporator (5) during the drying operation removes the water which is discharged and adhered onto the evaporator (5) characterized in that:

said water which is discharged from the discharging unit (13) is any one of a tap water, bath water and well water;

the clothes dryer (1) further comprising:
a drain port (12) provided below the evaporator (5) and configured to discharge the water generated on the evaporator (5) and the water discharged from the discharging unit (13) to an outside of the clothes dryer (1);

wherein the discharging unit (13) is provided above a downwind side of an end face (5b) on an upwind side of the evaporator (5), said upwind side being a side in which the drying air flows into the evaporator (5), said downwind side being opposite to the upwind side,

wherein the discharging unit (13) discharges the water to the end face (5b) on the upwind side of the evaporator (5) from above the evaporator (5),

wherein the discharging unit (13) discharges the water to a lint adhered onto the end face (5b) of the evaporator (5),

wherein the discharging unit (13) discharges the water such that a direction of the water is discharged in a direction opposite to the direction in which the drying air flows.
The clothes dryer (1) according to claim 1, wherein the controller is configured to control the water supply valve (15) to intermittently discharge the water from the discharging unit (13).
The clothes dryer (1) according to claim 1, wherein a water discharge area of the discharging unit (13) discharging the water to the evaporator (5) is a part of the evaporator (5).
A method of cleaning an evaporator (5) in a clothes dryer (1) comprising:
a drying chamber (9) for accommodating therein an article (20) to be dried;

an air passage (10) through which drying air discharged from the drying chamber (9) is circulated into the drying chamber (9) again;

a heat pump device (7) provided in the air passage (10) and including a compressor (2), a condenser (3), an expansion device (4), and an evaporator (5) connecting with a pipe (6) to circulate a refrigerant;

an air blower (8) for blowing air into the passage (10);

a discharging unit (13) for discharging water to the evaporator (5);

wherein the discharging unit (13) is provided above a downwind side of an end face (5b) on an upwind side of the evaporator (5), said upwind side being a side in which the drying air flows into the evaporator (5), said downwind side being opposite to the upwind side;

a controller (16) for controlling a drying operation, wherein the controller (16) controls a water supply valve (15) to supply the water to the discharging unit (13), and operates the compressor (2) to cool the evaporator (5) after discharging the water to the evaporator (5); and

a drain port provided below the evaporator (5) for discharging the water generated on the evaporator (5) and the water discharged from the discharging unit (13);

the method comprising:
a first step of discharging water to the evaporator (5) in the heat pump device (7) to remove lint adherent onto the evaporator (5), said water being any one of a tap water, bath water and well water;

wherein in the first step the water is discharged to the end face (5b) on the upwind side of the evaporator (5) from above the evaporator (5),

wherein the water is discharged to the lint adhered onto the end face (5b) of the evaporator (5),

wherein the water discharged from the discharging unit (13) is discharged such that a direction of the water discharged is in a direction opposite to the direction in which the drying air flows;

a second step of operating the compressor (2) to cool the evaporator (5);

a third step of operating the air blower (8) to blow the drying air, wherein after elapse of a predetermined time from execution of the second step, the third step is executed;

a fourth step of removing the water which is discharged and adhered to the evaporator (5) with water which is generated on the evaporator (5) during the drying process; and

a step of discharging the water generated on the evaporator (5) and the water discharged from the discharging unit (13) to the outside of the clothes dryer (1).