Cloth dryer

A cloth dryer includes heat-pump (30), rotary tub (5) for accommodating clothes (4) to be dried, blower (12) for supplying air heated by heat radiator (23) to rotary tub (5), and heat-exchange air flow paths (22, 24) for circulating the air stayed in rotary tub (5) through heat radiator (23) via heat absorber (21). Fins striding over heat absorber (21) and heat radiator (23) allow integrating absorber (21) and radiator (23) into one body which can be thus placed within air-flow paths (22, 24). Heat-transfer reducing section (32) is formed on the fins between heat absorber (21) and heat radiator (23) for reducing the heat transfer via the fins between heat absorber (21) and heat radiator (23). The foregoing structure can prevent frost and ice produced on heat absorber (21) from growing, so that a compact cloth dryer excellent in drying performance is obtainable.

This application is a 371 application of PCT/JP2008/001325 having an international filing date of May 28, 2008, which claims priority to JP2007-144804 filed May 31, 2007 and JP2008-109813 filed Apr. 21, 2008, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a cloth dryer to be used in a household washer-dryer for drying clothes.

BACKGROUND ART

A cloth dryer having a built-in heat pump, which allows effective use of heat, has been proposed recently (disclosed in e.g. Patent Literature 1). The heat pump is formed of the following structural elements:

a compressor for compressing a refrigerant;

a heat radiator for exchanging heat between the refrigerant, which has been compressed by the compressor and turned into a high temperature and high pressure state, and the ambient air, thereby radiating the heat from the refrigerant;

a throttling section for decompressing the highly pressurized refrigerant having undergone the heat radiator;

a heat absorber for exchanging heat between the refrigerant, which has been decompressed by the throttling section and turned into a low pressure and low temperature state, and the ambient air, thereby depriving the ambient air of the heat; and

a pipe line for the refrigerant to travel through the foregoing structural elements one by one.

The cloth dryer including the foregoing heat pump works this way: Drying air blown by a blower deprives clothes placed in a rotary drum of water, so that the air becomes humid. Then the blower transmits the air to the heat absorber of the heat pump through a circulating duct. The drying air of which heat is deprived by the heat absorber is dehumidified and conveyed to the heat radiator to be heated, and then circulated into the rotary drum again. The drying air repeats the foregoing steps, whereby the clothes are dried.

The structure disclosed in Patent Literature 1 allows the water vaporized from the clothes to form dew on the heat absorber, so that the clothes can be dried efficiently. On top of that, heat of hot wind containing the water from the clothes is absorbed by the heat absorber, and the heat is transmitted to the compressor via the refrigerant, which is heated by the compressor, and the heat of the refrigerant is radiated by the heat radiator for heating again the hot wind. The heat can be thus efficiently used.

The dryer using the heat pump disclosed in Patent Literature 1 allows the heat absorber to dehumidify the dumped clothes, so that the heat absorber can work as a heat absorbing source of a refrigerating cycle. Electric power is input for circulating the refrigerant, so that the heat radiator can heat the air for further vaporizing the water from the clothes. The foregoing steps are repeated.

However, the conventional cloth dryer using the heat pump discussed above takes a time before the clothes are warmed and ready for being used as the heat absorbing source of the refrigerating cycle, and the compressor resists increasing a pressure before the heat absorbing source is ready.

When the clothes are in a low temperature state or the cloth dryer per se is in a low temperature state because an ambient temperature is low, e.g. in winter, the air circulating through the heat absorber and the heat radiator, which form the refrigerating cycle, falls into a low temperature state. In such a case, the refrigerant flowing in the heat absorber should be controlled at a temperature lower than the temperature of this air in order to carry out the heat exchange between the refrigerant and the air, otherwise, the refrigerant cannot absorb the heat from the air.

The refrigerant flowing in the heat absorber thus remains not higher than 0° C. until the temperature of the circulating air rises to a given temperature. The water forms dew on the heat absorber and grows to frost or ice, which attaches to the surface of the heat absorber. As a result, the frost or ice attached to the surface blocks the circulating air and also disturbs the heat exchange between the refrigerant and the air.

In the heat absorber, the air is cooled greater as the air runs further down the flow, so that the temperature at the downstream becomes the lowest. The frost or ice thus starts growing from the downstream and blocks the circulating air, and also disturbs the heat exchange between the refrigerant and the air.

The frost or ice repeats growth and meltdown on the surface of the heat absorber until the circulating air is warmed to a given temperature. The water melted down drops to the underside of the heat absorber and is frozen again. The re-frozen ice-layer on the heat absorber blocks the circulating air and also disturbs the heat exchange between the refrigerant and the air.

On top of that, when the heat exchange between the refrigerant and the air is carried out unsatisfactorily due to the growth of frost or ice on the heat absorber, the refrigerant cannot fully evaporate and is sucked into the compressor in a liquid state. This phenomenon will affect the reliability of the compressor.

Patent Literature 2 discloses another structure of the heat pump used as a heat exchanger for a dehumidifier. A heat absorber and a heat radiator of this heat pump share fins and form a heat exchanger in one body, and slits are provided at the fins between the absorber and the radiator. This slit allows suppressing the flow of heat between the absorber and the radiator, so that they can be downsized.

However, in the heat exchanger disclosed in Patent Literature 2, pipe-lines for the refrigerant at the absorber and the radiator share the fin and the pipe-lines are adjacent to each other. The absorber and the radiator thus invite heat transfer through the fins between the adjacent pipe-lines, so that the efficiency of the heat exchange is lowered.

On top of that, when the air traveling through the heat exchanger is at a high temperature, the heat transfer discussed above makes it difficult for the heat radiator to maintain a refrigerant overcooled region, so that the dehumidifying capacity is lowered.

Another heat exchanger for an air-conditioner or a refrigerator is disclosed in, e.g. Patent Literature 3. In this heat exchanger, a rather longer cut section is provided at the following two places respectively: at a heat transfer pipe where a refrigerant enters and a rather higher temperature is kept, and at another heat transfer pipe where the refrigerant exits and a rather lower temperature is kept. This structure allows cutting off efficiently the heat conduction between the heat transfer pipes where temperatures different greatly from each other are kept, so that a greater refrigerant overcooled region can be obtained. As a result, a greater amount of heat exchange, i.e. a greater capacity of heat exchange, can be expected.

The heat exchanger disclosed in Patent Literature 3; however, in a case where multiple rows of refrigerant pipes exist between the entrance and the exit for the refrigerant, heat transfer occurs through the fins between the adjacent refrigerant pipes. The foregoing structure thus incurs degradation in the efficiency of maintaining a high temperature at the heat radiator, or degradation in the efficiency of maintaining a low temperature at the heat absorber. As a result, no further improvement in the efficiency can be expected regrettably.Patent Literature 1: Unexamined Japanese Patent Application Publication No. H07-178289Patent Literature 2: Unexamined Japanese Patent Application Publication No. 2002-310584Patent Literature 3: Granted Japanese Patent Publication No. 3769085

DISCLOSURE OF THE INVENTION

The present invention aims to provide a clothes dryer that can suppress the growth of frost or ice at a heat absorber even at a low ambient temperature. It also aims to provide a clothes dryer that expects a greater efficiency respectively in a heat absorber and a heat radiator. This clothes dryer allows the heat radiator to maintain an overcooled region by a refrigerant even when the air traveling at a high humidity through the heat exchanger. The clothes dryer thus can prevent the dehumidifying capacity from lowering and be excellent in drying efficiency.

The clothes dryer of the present invention comprises the following structural elements:

a heat pump including:

a compressor for compressing a refrigerant;

a heat radiator for exchanging heat between the refrigerant, compressed by the compressor into a high temperature and high pressure state, and the ambient air, thereby radiating the heat from the refrigerant;

a throttling section for decompressing the highly pressurized refrigerant having undergone the heat radiator;

a heat absorber for exchanging heat between the refrigerant, decompressed by the throttling section into a low pressure and low temperature state, and the ambient air, thereby depriving the ambient air of the heat; and

a pipe line connecting the foregoing structural elements to each other sequentially for the refrigerant to travel through them one by one,a tub for accommodating materials to be dried;a blower for supplying air heated by the heat radiator;a heat exchange air-flow path for circulating air staying in the tub to the heat radiator via the heat absorber; andfins striding over the heat radiator and the heat absorber for integrating them into one body and placing the one body within the heat exchange air-flow path.

The heat radiator and the heat absorber are respectively formed of refrigerant pipes which meander and extend along a given direction through the fins. A heat-transfer reducing section is placed extending along the same direction as the refrigerant pipe extends, and the heat-transfer reducing section works for suppressing the heat transfer through the fins between the radiator and the absorber.

The structure discussed above allows transferring the heat from the heat radiator to the heat absorber through the fins. As a result, even if a low ambient temperature grows frost, whereby the heat absorber is blocked up, the frost can be melted as the temperature of the refrigerant rises, so that drying efficiency can be prevented from lowering.

On top of that, since the heat absorber and the heat radiator are integrated into one body, the heat pump can be downsized, so that a compact clothes dryer excellent in the drying efficiency is obtainable.

The presence of the heat-transfer reducing section at the fins striding over the absorber and the radiator allows suppressing the heat transfer between the absorber and the radiator, so that degradation in the efficiency of dehumidifying and drying can be prevented.

DESCRIPTION OF REFERENCE SIGNS

PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION

Exemplary embodiments of the present invention are demonstrated hereinafter with reference to the accompanying drawings. The present invention is not limited to those embodiments.

FIG. 1shows a perspective appearance of a washer/dryer including a cloth dryer in accordance with the first embodiment of the present invention.FIG. 2shows a sectional view of the washer/dryer shown inFIG. 1and in drying operation, the washer/dryer is partially cut-away and viewed from right lateral face1bof the housing.FIG. 3shows the washer/dryer shown inFIG. 1and in drying operation, the washer/dryer is partially cut-away and viewed from rear face1cof the housing.FIG. 4schematically illustrates a structure of a heat pump mounted in the washer/dryer and the flow of drying air.FIG. 5shows an enlarged sectional view of a heat exchange air-flow path running in the washer/dryer.

As shown inFIG. 1-FIG.5, housing1of the washer/dryer includes cylindrical water tub3therein resiliently supported by multiple suspensions2, which absorb the vibration of water tub3during washing or spin-drying operation.

Water tub3includes cylindrical rotary tub5therein for accommodating clothes4, and is driven by motor6on a horizontal axis. Housing1has opening1aand door7, which opens/closes opening1a, at the front. A user inputs or takes out clothes4to/from water tub3through opening1a. Water tub3and rotary tub5also have openings3aand5brespectively at their front faces. Opening3aof water tub3connects with opening1aof housing1via bellows8in a water tight manner. Water tub3has a drain hole (not shown) at the bottom for draining wash-water. The drain hole connects with drain hose11via a drain valve (not shown).

Blower12is placed on an outer wall of water tub3at a corner space (located at an upper section of housing1) formed by top face1dof housing1and water tub3. A heat exchanger of heat pump30is placed at a lower section of the rear face of housing1. The heat exchanger includes heat-absorber air-flow path22, a part of a heat exchange air-flow path, for running the air to heat absorber21along arrow mark “e”, and heat radiator air-flow path24, also a part of the heat exchange air-flow path, for running the air to heat radiator23along arrow mark “f”.

On top of that, heat absorber21and heat radiator23are respectively formed of meandering refrigerant pipes21aand23aextending along one direction (vertical direction inFIG. 5). Heat absorber21and heat radiator23share a large number of flat fins25placed in parallel with each other and forming right angles with respect to the paper ofFIG. 5. Extension of refrigerant pipes21aand23athrough fins25allows integrating absorber21and generator23together in one body. Heat radiator23in particular includes two rows of refrigerant pipes23, i.e. one row extends vertically with refrigerant pipes23ain a slant and meandering manner, and the other row extends vertically with pipes23ain an upright manner. In other words, heat radiator23forms rows refrigerant pipes at the heat radiating side where multiple refrigerant pipes23aare arranged in parallel. Each one of pipes23ais connected to each other at its end, thereby forming a single refrigerant flow-path (corresponding to the refrigerant flow path at radiating side of the present invention). The structure discussed above is depicted inFIG. 4which illustrates the routing of pipe line28andFIG. 5which shows refrigerant pipes21aand23apartially cut away.

Refrigerant pipes21aand23aare made of well-known metal such as copper, copper alloy, aluminum, or aluminum alloy. Fin25is made of also well-know metal such as aluminum or aluminum alloy and forms a plate-like shape. Heat absorber21and heat radiator23can be assembled with a known method, so that the description thereof is omitted here.

Multiple cuts32are formed like a dashed line between heat absorber21and heat radiator23on fin25. Cuts32should be formed at least at the place where refrigerant pipes of absorber21and radiator23come closer to each other, and allow splitting fin25into the heat absorbing side and the heat generating side. Small connecting sections between respective cuts32form a heat conduction area (heat conduction section) between absorber21and generator23.

In this first embodiment, cuts32are formed as a heat-transfer reducing section; however, fins25can be punched out by a metal die to form cutout sections (not shown) with a fine width at the same place as cuts32so that an advantage similar to what is discussed above can be obtainable. Since the cutout sections reduce the area of fin25, forming of cuts32is better than forming of the cutout sections because a heat-exchanging area between fins25and the air can be maintained. Cuts32or the cutout sections form the heat-transfer reducing section of the present invention.

As discussed above, the sharing of fins25and the forming of cuts32as small as a dashed line allows preventing the air running through heat absorber21and heat radiator23from passing through cuts32and interfering with the adjacent air current (air current running on the rear face of fin25). As a result, the air can travel efficiently from heat absorber21to heat generator23.

In the case of using an air-flow circuit in which heat absorbing air-flow path22is placed close to heat generating air-flow path24and the air makes a U-turn after traveling through the heat exchanger, the air current traveling through heat absorber21and heat radiator23flows smooth. On top of that, heat absorbing air-flow path22and heat generating air-flow path24can be formed unitarily with the housing of absorber21and generator23into one body by resin molding. As a result, the heat pump can be downsized and mounted into a limited space on the rear face of housing1at a lower section.

As shown inFIG. 2, drying air blown by blower12runs through heat absorber21placed in heat-absorbing air-flow path22via flexible connection pipe19shaped like bellows as arrow mark “e” shows. Then the drying air travels through heat radiator23placed in heat-generating air-flow path23, flexible pipe19and blowing air-duct20as arrow mark “f” shows. Then as shown with arrow mark “b”, the air current flows into rotary tub5through air-inlet14and passes through clothes4in tub5. Finally, as shown with arrow mark “c” the air current runs through circulating duct15via discharging outlet16placed at the upper section of tub5and returns to blower12. The drying air blown by blower12circulates in a similar way to what is discussed above.

Heat pump30uses a flammable refrigerant because of the environmentally friend properties, and as shown inFIG. 4, heat pump30is formed of compressor26, heat radiator23, throttling section27, heat absorber21, and pipe line28that connects the foregoing elements sequentially for the refrigerant can flow through them one by one. The refrigerant thus circulates along the direction indicated by arrow marks “h” and “i”, thereby achieving a heat-pump cycle.

Compressor26used in this embodiment is a vertical type compressor for compressing a refrigerant. Heat radiator23radiates heat by exchanging the heat between the ambient air and the refrigerant kept at a high temperature and a high pressure due to the compression by compressor26. Throttling section27is formed of a throttle valve or capillary tubes for decompressing the refrigerant kept at a high pressure while the refrigerant has been heat-dissipated by heat radiator23. Heat absorber21exchanges heat between the ambient air and the refrigerant kept at a low temperature and a low pressure due to the decompression by throttling section27, thereby depriving the ambient air of heat.

Water reservoir29is placed below heat absorber21for receiving dew drops attached to absorber21placed in heat absorbing air-flow path22. The dew drops pooled in water reservoir29are pumped up by drain pump31and discharged outside the washer/dryer through drain hose11.

The washer/dryer discussed above operates this way: In a washing step, water feeding valve17is opened while the drain valve (not shown) is closed for feeding the tap water into water tub3through water supply hose18connected to a cock of a water pipe. The water is fed until a water level reaches a given level in water tub3, then motor6is driven for rotating rotary tub5accommodating clothes4and the washing water therein. The washing step is thus carried out.

In a rinsing step next to the washing step, the tap water is fed into water tub3as is done in the washing step, then rotary tub5is rotated for rinsing clothes4.

In a dehydrating step next to the rinsing step, the drain valve is opened for discharging the water in water tub3to the outside of the washer/dryer, and then rotary tub5accommodating clothes4is spun in one direction with motor6so that centrifugal force can be generated for dehydrating clothes4.

When the dehydrating step is completed, the step moves on to a drying step shown inFIG. 4. In this drying step, rotary tub5is driven at a given speed, and vertical type compressor26of heat pump30starts working as well as blower12starts working.

The refrigerant is thus compressed by compressor26into gaseous refrigerant in a high-pressure and high-temperature state. The gaseous refrigerant flows into heat radiator23as shown with arrow mark “h”, and is cooled by exchanging heat with the air flowing between each one of fins25, the gaseous refrigerant thus turns into liquid refrigerant.

The liquid refrigerant then flows to throttling section27where it undergoes adiabatic expansion and falls into a low-temperature and low-pressure state or turns into two-phase refrigerant in which liquid and gas are mixed, and then flows to heat absorber21along arrow mark “i” inFIG. 4.

In heat absorber21, the refrigerant exchanges heat with the air flowing between each one of fins25for being heated, and turns into gaseous refrigerant, which then returns to compressor26. The refrigerant circulates in heat pump30as discussed above.

The air, which has deprived clothes4of water, travels through blower12via discharging outlet16of water tub3, and flows into heat absorber21as indicated by arrow mark “c”. The air forms dew on the surface of heat absorber21which has been cooled to not higher than a dew point, whereby the air is dehumidified.

The air then flows into heat radiator23for being humidified, so that the air falls into a high-temperature and low-humidity state. The air then travels through air duct20and flows into water tub3as indicated by arrow mark “f”. Rotary tub5in water tub3is driven by motor6, so that clothes4are rolling in tub while they are agitated up and down.

The air in a high-temperature and low-humidity state flows in rotary tub5, and deprives clothes4of water when the air passes through clothes4, and the damped air runs through circulation duct15and blower12via discharging outlet16, and flows into heat absorber21again. The air circulates in the washer/dryer as discussed above.

The dew water formed on the surface of heat absorber21is pooled in water reservoir29placed under heat absorber21, and then drained through drain hose11to the outside of the washer/dryer by drain pump31.

As discussed above, use of the heat-exchange operation of heat pump30for drying clothes4allows heat absorber21to dehumidify a lot in an efficient manner, so that a drying efficiency can be increased, and a drying time can be reduced. As a result, energy can be saved.

Cuts32shaped like a dashed line are provided to the boundary between heat absorber21and heat radiator23which share fins25with each other, so that the heat from heat radiator23can travel to heat absorber21in an appropriate amount through small connecting sections between each one of cuts32even when a temperature of the refrigerant flowing through heat absorber21is not higher than 0° C. such as when an ambient temperature is low or the air passing through heat absorber21is in a low-temperature state. This appropriate amount of heat can prevent frost or ice formed on heat absorber21from growing. As a result, the foregoing structure allows preventing the efficiency of heat exchange between the drying air and the refrigerant from lowering even when the ambient temperature is low.

Cuts32can be formed along the direction (up and down direction in the drawing) of extending refrigerant pipes21a,23aforming meanders. This formation allows cuts32to be formed as one of the steps of producing a metal die of fins25. To be more specific, through holes of the refrigerant pipe on fin25can be made with the metal die, and this well-known method is done this way: Fin member is fed along one direction, e.g. from left to right while the details of the metal die are changed one by one, whereby the through hole is formed step by step before completion.

The formation of cuts32thus only needs feeding the fin member along the same direction as forming the through-holes of the refrigerant pipes on fins25by the metal die. It does not need feeding the fin member along a direction different from the direction for forming the through-holes, so that the number of steps for assembling the heat exchanger can be reduced.

On top of that, heat absorber21and heat generator23are integrated together into one body as one heat exchanger, so that the heat pump can be downsized. As a result, a downsized clothes dryer excellent in drying efficiency is obtainable.

In this first embodiment, opening1afor loading or taking out clothes4is located at a face of water tub3opposite to the face where motor6of rotary tub5is located; however, the location of opening1ais not limited to this place, but opening1acan be placed at any place of water tub3or rotary tub5.

The washer/dryer is not limited to a drum-type, but it can be a vertical type using a pulsator.

A flammable refrigerant is used in heat pump30in this embodiment; however, a natural refrigerant such as carbon dioxide or HFC-based refrigerant can be used. Compressor26is not limited to the vertical type, but it can be a horizontal type.

FIG. 6shows an enlarged sectional view of a heat exchange air-flow path of a washer/dryer in accordance with the second embodiment of the present invention. Elements similar to those in embodiment 1 have the same reference signs and the descriptions thereof in detail are omitted here.

In this second embodiment, heat absorber21and heat radiator23are placed slantingly such that the lowest portion of heat absorber21is located somewhat lower than the lowest portion of heat radiator23. This structure allows preventing the dew water formed on absorber21from moving toward radiator23, so that the dew water attached to absorber21can travel smoothly to water reservoir29. As a result, heat radiator23can be prevented from lowering the temperature due to water-splash from absorber21to radiator23, and a washer/dryer excellent in drying efficiency is obtainable.

In a case where a heat exchanger or fin25differing in shape is used, a slant placement of heat absorber21such that the lowest portion of absorber21is located lower than the lowest portion of heat radiator23can produce an advantage similar to what is discussed above.

FIG. 7shows an enlarged sectional view of a heat exchange air-flow path of a washer/dryer in accordance with the third embodiment of the present invention. Elements similar to those in embodiment 1 have the same reference signs and the descriptions thereof in detail are omitted here.

In this third embodiment, the placement of refrigerant pipe21aof heat absorber21is the same as heat radiator23. To be more specific, there are two rows of pipes21a, namely one row extends vertically and includes refrigerant pipe21aslanting, forming meanders, and running through fins25, and the other row runs through fins25, stands upright, and extends vertically. However, the refrigerant pipe belonging to the row standing upright and extending vertically is cancelled, and through-hole33left vacant intentionally (the refrigerant pipe does not run through).

The foregoing structure allows leaving a large space between absorber21and radiator23, so that the dew water generated on absorber21can be prevented more positively from moving to radiator23, and the dew water can be led more smoothly to water reservoir29. As a result, heat radiator23can be prevented more positively from lowering the temperature caused by water-splash from absorber21to radiator23, and the temperature of heat radiator23can be maintained at a high level, and a washer/dryer excellent in drying efficiency is obtainable.

Through-holes33, which are supposed to be used for the refrigerant pipe to run through, are used for suppressing the heat transfer between heat absorber21and heat radiator23, whereby the temperature of radiator23can be maintained at a high level. As a result, the drying efficiency can be prevented from lowering.

FIG. 8shows a perspective view of a heat exchanger formed of a heat absorber and a heat radiator of a washer/dryer in accordance with the fourth embodiment of the present invention.FIG. 9shows a lateral view of the heat exchanger. Elements similar to those used in the preceding embodiments have the same reference signs and the descriptions thereof in detail are omitted here. The drawings relevant to the first embodiment are used for describing the flow of a refrigerant.

InFIGS. 8 and 9, both of heat absorber21and heat radiator23of the heat exchanger are formed of one row of meandering refrigerant pipe21aand another row of meandering pipe23a, and the two rows extend in a vertical direction (as shown in the Figs.) respectively. The rows run through flat fins25. Refrigerant entrance21A and refrigerant exit21B of heat absorber21are not adjacent to each other, but they are most distantly placed away from each other. Refrigerant entrance23A and exit23B of heat radiator23are placed in a similar way. If they are obliged to be placed close to each other because of some design factor, it must be taken into consideration that they must not placed adjacently to each other. Arrow marks “h” and “i” indicate the flows of the refrigerant in radiator23and absorber21.

Cuts32aare formed like a dashed line on the boundary between heat absorber21and heat radiator23on fins25, and the line of cuts32aextends along refrigerant pipes21a,23a(vertical direction in the Figs.) Cuts32ain a dashed line are intermitted with small parts in spots in order to prevent fins25from being readily broken into parts by cuts32a.

Cuts32aare not necessarily shaped like a dashed line, but they can be a sequence of slits having a given length and intermittently formed, or a sequence of cutouts having a very narrow width and punched out by a metal die on fins25at the same places as cuts32aintermittently.

Slit-like cut32bis formed on the boundary between refrigerant overheated region55at refrigerant entrance23A side of heat radiator23and refrigerant two-phase region56. Overheated region55refers to a region where the temperature of the refrigerant is higher than the saturation temperature, and two-phase region56refers to the region where the temperature of the refrigerant is the saturation temperature. Cut32bis formed along a direction (right-left direction) crossing the direction of refrigerant pipe23awhich extends in a meanders manner (vertical direction). Cut32bcorresponds to the heat-transfer reducing section on the overheated region side of the present invention. Cut32bcan be a dashed line or cutouts similar to cut32a.

On top of that, slit-like cut32cis formed on the boundary between refrigerant overcooled region57at refrigerant exit23B side of heat radiator23and refrigerant two-phase region56. Overcooled region57refers to a region where the temperature of the refrigerant is lower than the saturation temperature. Cut32cis formed along a direction, like cut32b, crossing the direction of refrigerant pipe23awhich extends in a meanders manner. Cut32ccorresponds to the heat-transfer reducing section on the overcooled region side of the present invention. Cut32ccan be a dashed line or a cutout similar to cut32a.

In the drying step of the washer/dryer equipped with the heat exchanger discussed above, the refrigerant compressed by compressor26enters at refrigerant entrance23A of heat radiator23as shown with arrow mark “h”, and reaches heat absorber21through exit23B and throttling section27. Then the refrigerant enters at entrance21A and flows through exit21B to compressor26.

The wind generated by blower12blows along arrow mark “e” inFIG. 9, and when the wind passes through heat absorber21, the water contained in the wind forms dew on absorber21. Then the wind is warmed when it passes through heat radiator23and turns into dry air at a high temperature, so that this dry air serves clothes4in rotary tub5to dry.

The presence of cuts32ashaped like a dashed line on the boundary between heat absorber21and heat radiator23of the heat exchanger allows reducing the heat transfer from radiator23to absorber21. Absorber21and radiator23can be thus prevented from lowering the efficiency caused by the heat transfer. On the other hand, heat quantity necessary for preventing the frost or ice formed on absorber21from growing can be conveyed from radiator23to absorber21through the small connecting sections between each one of cuts32a.

As a result, the forming of frost on heat absorber21can be suppressed when the ambient temperature (the temperature of the air passing through absorber21and radiator23) is low, and the heat exchanging efficiency between the drying air and the refrigerant can be prevented from lowering.

The presence of cut32ballows reducing the heat transfer between refrigerant two-phase region56and refrigerant overheated region55of which temperature is greatly higher than that of region56. The presence of cut32calso allows reducing the heat transfer between refrigerant two-phase region56and refrigerant overcooled region57of which temperature is lower than that of two-phase region56. As a result, the air passing through overheated region55and two-phase region56in heat radiator can be heated efficiently.

In other words, cut32bprevents overheated region55from lowering the temperature due to the heat transfer from overheated region55to two-phase region56, so that a difference in temperature between the air and the refrigerant can be increased. Cut32cprevents the heat transfer to overcooled region57, which is thus hardly affected by the heat from two-phase region56and overheated region55that has a higher temperature.

As a result, in overcooled region57, the refrigerant can be so overcooled that it tends to be stable in liquid state. The temperature in overheated region55indeed drops due to the heat transfer; however, the drop of temperature can be suppressed, so that the air passing through heat radiator23can be heated efficiently. The dew can be thus readily formed on heat absorber21so that the drying air at a high temperature is obtainable, and the drying performance can be thus stabilized.

On top of that, when the air passing through radiator23is at a high temperature, it is difficult for the refrigerant to be overcooled on radiator23side, so that the refrigerant in the two-phase state flows into throttling section27. In such a case, a smaller quantity of refrigerant circulates and the temperature of heat absorber21rises, so that a smaller quantity of dew is formed on absorber21.

However, as discussed previously, the small connecting sections between each one of cuts32ashaped like a dashed line allows the heat to travel, so that the frost formation on absorber21can be suppressed when the temperature is low, and yet, the small connecting sections allow the heat to travel between absorber21and radiator23even when the temperature of the air is high. As a result, the heat transfer from the overheated region to the overcooled region can be reduced, and also the environment, where the refrigerant can be readily stabilized in the liquid state at refrigerant exit23B of heat radiator23, can be formed. The refrigerant in liquid state thus flows into throttling section27.

The refrigerant having undergone throttling section27turns into the two-phase state where liquid and gas are mixed, and then flows into heat absorber21, which deprives the refrigerant of heat. Therefore, in a case where the air temperature is high, the dew can be formed on absorber21, so that the drying air is obtainable.

In this fourth embodiment, cut32bis formed between refrigerant overheated region55and refrigerant two-phase region56, and cut32cis formed between refrigerant overcooled region57and two-phase region56. However, overcooled region57can be greater according to the properties of the heat exchanger, then cut32cin overcooled region57can be eliminated.

The heat exchanger in accordance with this fourth embodiment can be placed slantingly, as it is done in embodiment 2, in the heat exchange air-flow path which connects heat absorbing air-flow path22to heat radiating air-flow path24. This structure also produces advantages similar to what are discussed above.

Overheated region55, two-phase region56and overcooled region57inFIGS. 8 and 9are defined univocally, and the locations thereof can be changed depending on the properties of the heat exchanger. Therefore, the locations of cut32band cut32ccan be set in response to the state of the heat exchanger where a volume of heat load and a heat-pump cycle are stabilized.

FIG. 10shows a lateral view of a heat exchanger formed of a heat absorber and a heat radiator of a washer/dryer in accordance with the fifth embodiment of the present invention. Elements similar to what are used in the preceding embodiments have the same reference marks, and the descriptions thereof in detail are omitted here. The drawings relevant to the first embodiment are used for describing the flow of a refrigerant as they are used in the previous embodiment.

As shown inFIG. 10, heat radiator23of the heat exchanger includes two independent rows of refrigerant pipes23awhich form meanders and extend along one direction (vertical direction inFIG. 10). The two rows are placed on one straight line respectively, and each row extends through fins25, so that two circuits are formed. Refrigerant entrance23A and refrigerant exit23B of heat radiator23are placed at two places respectively not adjacent to each other.

Cuts32a(heat-transfer reducing section) are formed on the boundary between heat absorber21and heat radiator23, and cut32bis formed on the boundary between refrigerant overheated region55and refrigerant two-phase region56, cut32cis formed on the boundary between two-phase region56and refrigerant overcooled region57. Cut32bis referred to a heat-transfer reducing section on the overheated region side, and cut32cis referred to a heat-transfer reducing section on the overcooled region side. Heat absorber21uses the same structure as that used in embodiment 4.

In the drying step of the washer/dryer equipped with the foregoing heat exchanger, wind from blower12flows along arrow mark “e” inFIG. 10, and when the wind (air) runs through heat absorber21, the water contained in the air form dew on absorber21. Then the air is warmed and dried when it travels through heat radiator23, and the air serves the clothes in rotary tub5to dry.

In this state, the refrigerant is discharged from compressor26, and then divided as indicated with arrow marks “h”, namely, the refrigerant enters at entrances23A located at the upper and lower ends inFIG. 10, and flows to exits23B located at the center inFIG. 10. Then the refrigerant joins to each other and flows to absorber21via throttling section27, and then the refrigerant flows at entrance21A to exit21B, and reaches compressor26as indicated with arrow mark “i”. During the foregoing course, refrigerant overheated region55, two-phase region56, and overcooled region57are formed in heat radiator23.

The presence of cuts32ashaped like a dashed line and formed on the boundary between absorber21and radiator23allows the heat transfer from radiator23to absorber21to decrease, and thus the lowering in efficiency, caused by the heat transfer, of absorber21and radiator23can be prevented. On the other hand, the heat can travel from radiator23to absorber21through the small connecting sections formed between each one of cuts32ashaped like a dashed line, thereby preventing frost or ice formed on absorber21from growing.

As a result, the lowering of the efficiency in heat exchange between the drying air and the refrigerant can be suppressed in a case where the ambient air temperature (the temperature of the air traveling through radiator23and absorber21) is low.

The presence of cut32ballows reducing the heat transfer between refrigerant two-phase region56and refrigerant overheated region55of which temperature is greatly higher than that of region56. The presence of cut32calso allows reducing the heat transfer between refrigerant two-phase region56and refrigerant overcooled region57of which temperature is lower than that of two-phase region56. As a result, the air passing through overheated region55and two-phase region56in heat radiator23can be heated efficiently.

As a result, similar to embodiment 4, in overcooled region57, the refrigerant can be so overcooled that it tends to be stable in liquid state, and the air passing through heat radiator23can be heated efficiently. The dew can be thus readily formed on heat absorber21, so that the drying performance can be stabilized.

On top of that, in a case where the temperature of the air passing through radiator23is high, the heat can travel through the small connecting sections formed between each one of cuts32ashaped like a dashed line, so that the refrigerant at exit23B of radiator23turns into liquid, and the drying air can be thus obtained due to the dew formed by cooling operation of absorber21and a temperature-rise (heating) by radiator23.

Refrigerant overcooled region57can be greater according to the properties of the heat exchanger, then cut32cin overcooled region57can be eliminated. The heat exchanger in accordance with this fifth embodiment can be placed slantingly, as it is done in embodiment 2, in the heat exchange air-flow path which connects heat absorbing air-flow path22to heat radiating air-flow path24. This structure also produces advantages similar to what are discussed above.

Overheated region55, two-phase region56and overcooled region57inFIG. 10are defined univocally, and the locations thereof can be changed depending on the properties of the heat exchanger. Therefore, the locations of cut32band cut32ccan be set in response to the state of the heat exchanger where a volume of heat load and a heat-pump cycle are stabilized.

FIG. 11shows a lateral view of a heat exchanger formed of a heat absorber and a heat radiator of a washer/dryer in accordance with the sixth embodiment of the present invention. Elements similar to what are used in the preceding embodiments have the same reference marks, and the descriptions thereof in detail are omitted here. The drawings relevant to the first embodiment are used for describing the flow of a refrigerant as they are used in the previous embodiment.

InFIG. 11, the heat exchanger is formed of elements similar to those of embodiment 4; however, it greatly differs from embodiment 4 in the structure of fin25. In this sixth embodiment, fin25aon heat absorber21side forms a corrugated-fin, and fin25bon heat radiator23side forms a flat-fin; however, fin25bis not necessarily a flat one.

In the drying step of the washer/dryer equipped with the heat exchanger discussed above, the refrigerant compressed by compressor26enters at refrigerant entrance23A of heat radiator23as shown with arrow mark “h”, and reaches heat absorber21through exit23B and throttling section27. Then the refrigerant enters at entrance21A and flows through exit21B to compressor26.

The wind generated by blower12blows along arrow mark “e” inFIG. 11, and when the wind passes through heat absorber21, the water contained in the wind forms dew on absorber21. Then the wind is warmed when it passes through heat radiator23and turns into dry air at a high temperature, so that this wind serves clothes4in rotary tub5to dry.

The presence of corrugated-fin25aon absorber21side, where dew is to be formed, allows producing an advantage similar to that produced in embodiment 4, and corrugated-fin25aallows the dew water formed on absorber21to drain away along the gravity direction with ease. Corrugated-fin25amakes the dew water attached thereto resist flowing into heat radiator23placed down the wind because the dew water tends to be pushed by the air current, so that the dew water is prevented from re-evaporating from radiator23. As a result, higher drying performance is achievable.

The heat exchanger in accordance with this sixth embodiment can be placed slantingly, as it is done in embodiment 2, in the heat exchange air-flow path which connects heat absorbing air-flow path22to heat radiating air-flow path24. This structure also produces advantages similar to what are discussed above.

The refrigerant path in heat radiator23is solely formed of refrigerant pipe23a; however, multiple refrigerant pipes, in which the refrigerant flows in parallel, can be used instead. In this case, cuts32a,32b, and32calso work similarly and produce advantages similar to what are discussed above.

FIG. 12shows a lateral view of a heat exchanger formed of a heat absorber and a heat radiator of a washer/dryer in accordance with the seventh embodiment of the present invention. Elements similar to what are used in the preceding embodiments have the same reference marks, and the descriptions thereof in detail are omitted here. The drawings relevant to the first embodiment are used for describing the flow of a refrigerant as they are used in the previous embodiment.

InFIG. 12, the heat exchanger is formed of elements similar to those of embodiment 6; however, it greatly differs from embodiment 6 in the structure of fin25. In this seventh embodiment, fin25aon heat absorber21side has a corrugated-fin, and fin25bon heat radiator23side has a slit-fin having a large number of slits80.

In the drying step of the washer/dryer equipped with the heat exchanger discussed above, the wind generated by blower12blows along arrow mark “e” inFIG. 12, and when the wind passes through heat absorber21, the water contained in the wind forms dew on absorber21. Then the wind is warmed when it passes through heat radiator23and turns into dry air at a high temperature, so that this wind serves clothes4in rotary tub5to dry.

Slit-fins25bon radiator23side allows suppressing the degrading in the drying performance as seen in embodiment 5, where the degrading is caused by the flow-in of dew water attached to absorber21to radiator23. On top of that, advantages similar to what are discussed in embodiment 5 can be expected, and slit-fin25bcan increase the heat exchange performance of heat radiator23.

In addition to the advantages discussed above, cut32bformed between refrigerant overheated region55and refrigerant two-phase region56as well as cut32cformed between two-phase region56and overcooled region57can reduce the heat transfer between them, so that a temperature fall of the drying air caused by the heat transfer can be suppressed.

In a case where the temperature of the air flowing through the heat exchanger is high or low, an appropriate heat conduction can be done through the small connecting sections between each one of cuts32aformed between absorber21and radiator23. This appropriate heat conduction allows reducing frost formed on absorber21, or suppressing the reduction in the overcooled region. As a result, the drying performance can be prevented from lowering.

The heat exchanger in accordance with this seventh embodiment can be placed slantingly, as it is done in embodiment 2, in the heat exchange air-flow path which connects heat absorbing air-flow path22to heat radiating air-flow path24. This structure also produces advantages similar to what are discussed above.

The refrigerant path in heat radiator23is solely formed of refrigerant pipe23a; however, multiple refrigerant pipes in which the refrigerant flows in parallel can be used instead. In this case, cuts32a,32b, and32calso work similarly and produce advantages similar to what are discussed above.

FIG. 13shows a perspective view of a heat exchanger formed of a heat absorber and a heat radiator of a washer/dryer in accordance with the eighth embodiment of the present invention.FIG. 14shows a lateral view of the heat exchanger. Elements similar to what are used in the preceding embodiments have the same reference marks, and the descriptions thereof in detail are omitted here. The drawings relevant to the first embodiment are used for describing the flow of a refrigerant as they are used in the previous embodiment.

As shown inFIGS. 13 and 14, heat absorber21of the heat exchanger includes one row of meandering refrigerant pipe21aextending along one direction, and pipe21aarranged vertically runs through flat-fins25shared by heat absorber21and heat radiator23.

Heat radiator23of the heat exchanger includes multiple rows60,61,62(indicated respectively with a long dashed double-short dashed line) of meandering refrigerant pipes23a. Refrigerant pipes23aarranged vertically extend through flat-fins25shared by absorber21and radiator23. In other words, three rows60,61,62of refrigerant pipes23aform the refrigerant-pipe rows on the heat radiating side. Both of the ends of pipe23aon center row61are connected to first ends of pipes23aon rows60,62adjacent to row61, so that a single refrigerant path on the heat radiation side is formed, whereby refrigerant entrance23A can be placed away from refrigerant exit23B.

Cuts32dshaped like a dashed line are formed between row60and adjacent row61and along the direction (vertical direction inFIG. 13) of extending refrigerant pipe23a. Row60includes refrigerant overheated region55on fins25of heat radiator23side. Cuts32drefer to the heat-transfer reducing sections.

Cuts32ashaped like a dashed line are formed on the boundary between heat absorber21and heat radiator23on fins25, and cuts32aextend along the extending direction of pipe23a. Cuts32arefer to the heat-transfer reducing sections, and reduce the heat transfer from radiator23to absorber21.

Cuts32dare not necessarily shaped like a dashed line, but they can be a sequence of slits having a given length and intermittently formed, or a sequence of cutouts having a very narrow width and punched out by a metal die on fins25at the same places as cuts32aintermittently.

In the drying step of the washer/dryer equipped with the foregoing heat exchanger, the refrigerant compressed by compressor26enters at refrigerant entrance23A of heat radiator23as indicated by arrow mark “h”, and reaches heat absorber21through exit23B and throttling section27. Then the refrigerant enters at entrance21A and flows through exit21B to compressor26as indicated by arrow mark “i”.

The wind generated by blower12blows along arrow mark “e” inFIG. 14, and when the wind passes through heat absorber21, the water contained in the wind forms dew on absorber21. Then the wind is warmed when it passes through heat radiator23and turns into dry air at a high temperature, so that this dry air serves clothes4in rotary tub5to dry.

In this state, the heat exchanger reduces an amount of the heat conduction from heat radiator23to heat absorber21because of the presence of cuts32ashaped like a dashed line. On the other hand, the heat traveling through the small connecting sections formed between each one of cuts32aprevents frost or ice formed on absorber21from growing. As a result, in a case where an ambient temperature is low or the temperature of the air passing through the heat exchanger is low, the foregoing structure can prevent the efficiency of heat exchange between the drying air and the refrigerant from lowering.

On top of that, cuts32dshaped like a dashed line and formed between row60and row61allows reducing an amount of the heat conduction through fins25between row60and row61, where row60includes refrigerant overheated region55of which temperature is greatly higher than that of the refrigerant two-phase region, and row61adjacent to row60includes the two-phase region or overcooled region57(shown inFIG. 14). This structure allows heating the air passing through heat radiator23in an efficient manner, so that the drying performance can be improved.

Cuts32dgreatly affect overcooled region57in radiator23when the ambient temperature of the temperature of the air passing through the heat exchanger is high.

To be more specific, as already described in embodiment 4, in a case where the temperature of the air passing through heat radiator23is high, it tends to be difficult to maintain the refrigerant in liquid state at overcooled region57in radiator23. However, as similar to the case where the temperature is low, there is an appropriate amount of heat transfer between radiator23and absorber21, and yet, cut32dreduces the heat conduction from overheated region55to overcooled region57. As a result, fewer factors exist in overcooled region57for blocking the heat transfer to/from absorber21.

In other words, refrigerant overcooled region57resists being affected by the heat from overheated region55due to the presence of cuts32d, so that a difference in temperature between overcooled region57and absorber21is small. Since the heat transfer between overcooled region57and absorber21is done in this state, i.e. there is a small difference in the temperatures, overcooled region57can be formed steadily in row62.

As a result, the refrigerant turns into a liquid state at refrigerant exit23B of radiator23, and stays as the liquid state or turns into the two-phase state, where liquid and gas are mixed, at throttling section27, and then flows into heat absorber21. In the case of a high ambient temperature, the foregoing mechanism allows the temperature of heat absorber21to lower so that dew can be formed on absorber21. The dehumidifying capacity can be thus maintained.

In heat radiator23, a temperature drop at overheated region55caused by the heat transfer can be suppressed, so that the air passing through heat radiator can be heated efficiently.

As a result, the dew can be formed positively on heat absorber21, and the drying air at a high temperature is obtainable, which results in an improvement in drying performance.

The locations of overheated region55and overcooled region57in accordance with embodiment 8 are univocally defined; the locations thereof can be changed depending on a shape of the fins of the heat exchanger, or the number of rows formed of meandering refrigerant pipe23a. Therefore, the location of cuts32dcan be set in response to the structure (properties) of the heat exchanger.

The heat exchanger in accordance with this eighth embodiment can be placed slantingly, as it is done in embodiment 2, in the heat exchange air-flow path which connects heat absorbing air-flow path22to heat radiating air-flow path24. This structure also produces advantages similar to what are discussed above.

Row62shown inFIG. 14can be eliminated depending on the properties and capacity of the heat exchanger, and the through-holes (not shown) for the refrigerant pipes can be used for reducing the heat transfer from radiator23to absorber21as they are used in embodiment 3.

In this eighth embodiment, flat-fins25are used; however, the fins at absorber21can be corrugated as seen in embodiments 5 and 6. In this case, dew water formed on absorber21drains along the gravity direction with ease, and the dew water resists flowing into heat radiator23placed down the wind because the dew water tends to be pushed by the air current, so that the dew water is prevented from re-evaporating from radiator23. As a result, the washer/dryer more excellent in drying performance is achievable.

Fins25at heat radiator23can be slit-fins, so that the capacity of heat exchange between the air and the refrigerant can be increased, thereby enhancing the drying performance.

Fins25at absorber21can be corrugated-fins, and those at radiator23can be slit-fins, whereby the heat exchanger excellent in drainage performance and heat exchange performance is achievable.

The refrigerant flow-path in heat radiator23is formed of multiple rows of flow-paths solely formed of refrigerant pipe23a; however, as described in embodiment 5, multiple refrigerant flow-paths can be placed vertically or horizontally so that the refrigerant can flow in parallel. In this case, cuts32aand cuts32dcan be formed similarly to the foregoing structure for producing advantages similar to what are discussed above.

Cuts32aand cuts32dused in embodiment 8 are formed at different intervals in places so that fins25cannot be broken into parts by those cuts32a, and32d.

FIG. 15shows a lateral view of a heat exchanger formed of a heat absorber and a heat radiator of a washer/dryer in accordance with the ninth embodiment of the present invention. Elements similar to what are used in the preceding embodiments have the same reference marks, and the descriptions thereof in detail are omitted here. The drawings relevant to the first embodiment are used for describing the flow of a refrigerant as they are used in the previous embodiment.

The heat exchanger shown inFIG. 15includes cuts32e(heat-transfer reducing sections) shaped like a dashed line in addition to the structure of the heat exchanger in accordance with embodiment 8. Cuts32eare formed along the extending direction of pipes23aand between row61and row62of refrigerant pipe23aon fins25at heat radiator25.

In the drying step of the washer/dryer equipped with the heat exchanger discussed above, the refrigerant compressed by compressor26enters at refrigerant entrance23A of heat radiator23as indicated with arrow mark “h”, and reaches heat absorber21through exit23B and throttling section27. Then the refrigerant enters at entrance21A and flows through exit21B to compressor26as indicated with arrow mark “i”.

The wind generated by blower12blows along arrow mark “e” inFIG. 15, and when the wind passes through heat absorber21, the water contained in the wind forms dew on absorber21. Then the wind is warmed when it passes through heat radiator23and turns into dry air at a high temperature, so that this dry air serves clothes4in rotary tub5to dry.

In this state, row60at heat generator23includes refrigerant overheated region55, and row61adjacent to row60includes refrigerant two-phase region56, and row62adjacent to row61includes refrigerant overcooled region57. In addition to the advantages described in embodiment 7, presence of cuts32eshaped like a dashed line and formed between row61and row62allows suppressing the heat transfer via fins25from two-phase region56to overcooled region57of which temperature is greatly lower than that of two-phase region56.

As discussed above, cuts32esuppresses the heat transfer from two-phase region56and overheated region55to overcooled region57which has the lowest temperature. As a result, in addition to the advantages described in embodiment 8, overcooled region57can be formed more steadily in row62.

Therefore, in a case where an ambient temperature is high or the temperature of the air passing through the heat exchanger is high, in particular, the overcooled refrigerant (liquid refrigerant) can be obtained more steadily on row62. Dew can be also formed more readily on heat absorber21, so that the dehumidifying capacity can be prevented from lowering.

The structure discussed above also allows suppressing a temperature drop caused by the heat transfer between overheated region55and two-phase region56, so that the air dehumidified by heat absorber21can be heated efficiently and the drying performance can be improved.

In this ninth embodiment, flat-fins25are used; however, the fins at absorber21can be corrugated. In this case, dew water formed on absorber21drains along the gravity direction with ease, and the dew water resists flowing into heat radiator23placed down the wind because the dew water tends to be pushed by the air current, so that the dew water is prevented from re-evaporating from radiator23. As a result, the washer/dryer more excellent in drying performance is achievable.

Fins25at heat radiator23can be slit-fins, so that the capacity of heat exchange between the air and the refrigerant can be increased, thereby enhancing the drying performance.

Fins25at absorber21can be corrugated-fins, and those at radiator23can be slit-fins, whereby the heat exchanger excellent in drainage performance and heat exchange performance is achievable. Fins25as a whole can be slit-fins.

The locations of overheated region55, two-phase region56, and overcooled region57in accordance with embodiment 9 are univocally defined; the locations thereof can be changed depending on a shape of the fins of the heat exchanger, or the number of rows formed of meandering refrigerant pipe23a. Therefore, the location of cuts32dand cuts32ecan be set in response to the structure (properties) of the heat exchanger.

The heat exchanger in accordance with this ninth embodiment can be placed slantingly, as it is done in embodiment 2, in the heat exchange air-flow path which connects heat absorbing air-flow path22to heat radiating air-flow path24. This structure also produces advantages similar to what are discussed above.

Row62shown inFIG. 15can be eliminated depending on the properties and capacity of the heat exchanger, and the through-holes (not shown) for the refrigerant pipe can be used for reducing the heat transfer from radiator23to absorber21as they are used in embodiment 3.

The refrigerant flow-path in heat radiator23is formed of multiple rows of flow-paths solely formed of refrigerant pipe23a; however, as described in embodiment 5, multiple refrigerant flow-paths can be placed vertically or horizontally so that the refrigerant can flow in parallel. In this case, cuts32a,32d, and32ecan be formed similarly for producing advantages similar to what are discussed above.

Cuts32a, cuts32d, and cuts32eused in embodiment 9 are formed at different intervals in places so that fins25cannot be broken into parts by those cuts32a,32d, and32e.

FIG. 16shows a lateral view of a heat exchanger formed of a heat absorber and a heat radiator of a washer/dryer in accordance with the tenth embodiment of the present invention. Elements similar to what are used in the preceding embodiments have the same reference marks, and the descriptions thereof in detail are omitted here. The drawings relevant to the first embodiment are used for describing the flow of a refrigerant as they are used in the previous embodiment.

As shown inFIG. 16, heat absorber21of the heat exchanger includes two rows71,72(indicated with long dashed double-short dashed line) of meandering refrigerant pipes21a. The two rows extend along one direction, and are arranged vertically, and pipes21arun through flat-fins25which are shared by absorber21and heat radiator23. In other words, two rows of refrigerant pipes21aform a refrigerant pipe-row at the heat absorbing side. Pipes21aof rows71,72are connected to each other at their first ends, thereby forming a unit of a refrigerant flow path. Refrigerant entrance21A and refrigerant exit21B are placed at the upper section inFIG. 16.

Heat radiator23of the heat exchanger includes two rows60,61(indicated with long dashed double-short dashed line) of meandering refrigerant pipes23a. The two rows extend along one direction, and are arranged vertically, and pipes23arun through flat-fins25which are shared by absorber21and heat radiator23. Pipes23aof rows60,61are connected to each other at their first ends, thereby forming a unit of a refrigerant flow path. Refrigerant entrance23A and refrigerant exit23B are placed at the upper section inFIG. 16.

Cuts32ashaped like a dashed line are formed on the boundary between absorber21and radiator23on fins25, and cuts32a(heat-transfer reducing sections) extends along the extending direction of refrigerant pipes21aand23a(vertical direction). Cuts32athus reduce the heat transfer from radiator23to absorber21.

Cuts32dshaped like a dashed line are formed between row60including refrigerant overheated region55and row61adjacent to row60. Row61can include refrigerant two-phase region56or overcooled region57depending on load. Cuts32dextend along the extending direction of refrigerant pipes23a, and they work as the heat-transfer reducing sections. On top of that, cuts32fshaped like a dashed line are formed between row71and adjacent row72. Row71includes a refrigerant overcooled region or a refrigerant two-phase region70(hereinafter referred to as a low temperature region) at absorber21. Cuts32fwork as the heat-transfer reducing section at the heat absorber.

Cuts32fare not necessarily shaped like a dashed line, as described in embodiment 4, but they can be a sequence of slits having a given length and intermittently formed, or a sequence of cutouts having a very narrow width and punched out by a metal die on fins25at similar places to cuts32aintermittently.

As indicated with arrow marks “h” and “i”, the refrigerant flows from radiator23to absorber21, so that the water contained in the air forms dew on absorber21, and the air passing through absorber21can be heated.

This tenth embodiment thus can produce the following advantage in addition to the advantages described in the ninth embodiment: Presence of cuts32fshaped like a dashed line at heat absorber21reduces the heat conduction in heat absorber21, i.e. the heat conduction via fins25between row71including low-temperature region70at a low temperature and row72including overheated region (hereinafter referred to as a high temperature region)73.

In a case where row72has no overheated region, an evaporation temperature of the refrigerant is lowered due to a pressure drop in absorber21, and a difference in the temperatures between rows71and72is changed. In such a case, the foregoing structure allows reducing an amount of the heat conduction via the fins between rows71and72.

The refrigerant evaporates in absorber21, therefore, abrasion loss occurs between the inner wall of the refrigerant pipe and the refrigerant, and acceleration loss caused by an increment in volume of the refrigerant is added to the abrasion loss. The pressure drop in absorber21is thus far greater than a pressure drop in radiator23, so that the temperature of the refrigerant changes greatly. In this environment, cuts32fat absorber21can produce a great effect.

As a result, heat absorber21increases an amount of heat exchange between the air and the refrigerant, and efficiently dehydrates the water contained in the air, so that the drying performance can be further improved.

In this tenth embodiment, flat-fins25are used; however, the fins at absorber21can be corrugated. In this case, dew water formed on absorber21drains along the gravity direction with ease, and the dew water resists flowing into heat radiator23placed down the wind because the dew water tends to be pushed by the air current, so that the dew water is prevented from re-evaporating from radiator23. As a result, the washer/dryer more excellent in drying performance is achievable.

Fins25at heat radiator23can be slit-fins, so that the capacity of heat exchange between the air and the refrigerant can be increased, thereby enhancing the drying performance.

Fins25at absorber21can be corrugated-fins, and those at radiator23can be slit-fins, whereby the heat exchanger excellent in drainage performance and heat exchange performance is achievable. Fins25as a whole can be slit-fins.

The locations of overheated region55, two-phase region56, overcooled region57at radiator23, and low temperature region70, high temperature region73at absorber21in accordance with the tenth embodiment are univocally defined; the locations thereof can be changed depending on a shape of the fins of the heat exchanger, or the number of rows formed of meandering refrigerant pipes21aand23a. Therefore, the location of cuts32dand cuts32fcan be set in response to the structure (properties) of the heat exchanger.

The heat exchanger in accordance with this tenth embodiment can be placed slantingly, as it is done in embodiment 2, in the heat exchange air-flow path which connects heat absorbing air-flow path22to heat radiating air-flow path24. This structure also produces advantages similar to what are discussed above.

Row71shown inFIG. 16can be eliminated depending on the properties and capacity of the heat exchanger, and then one row of the refrigerant flow-path is used. The through-holes (not shown) for the refrigerant pipes eliminated can be used for reducing the heat transfer from radiator23to absorber21as they are so used in embodiment 3.

The refrigerant flow-paths in absorber21and radiator23are formed of multiple rows of flow-paths solely formed of refrigerant pipes21aand23a; however, as described in embodiment 5, multiple refrigerant flow-paths can be placed vertically or horizontally so that the refrigerant can flow in parallel. In this case, cuts32a,32d, and32fcan be formed similarly to the foregoing structure for producing advantages similar to what are discussed above.

Cuts32a, cuts32d, and cuts32fused in this embodiment 10 are formed at different intervals in places so that fins25cannot be broken into parts by these cuts32a,32d, and32f.

Industrial Applicability

A washer/dryer of the present invention is formed of a heat absorber and heat radiator integrated together in one body, so that frost or ice produced on the heat absorber can be prevented from growing even when an ambient temperature is low. As a result, a clothes dryer excellent in drying performance or a washer/dryer equipped with the clothes dryer is obtainable.