CN108691179B

CN108691179B - Clothes drying appliance

Info

Publication number: CN108691179B
Application number: CN201810272688.7A
Authority: CN
Inventors: P·巴勒蒂阿斯皮利奎塔; J·A·鲁伊斯贝尔梅霍; R·圣马丁桑乔
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2017-03-31
Filing date: 2018-03-29
Publication date: 2021-09-21
Anticipated expiration: 2038-03-29
Also published as: CN108691179A

Abstract

A laundry drying appliance (2) comprises a process air channel (1) and a heat pump (3, 4, 5), wherein an evaporator (3) and a condenser (5) of the heat pump (3, 4, 5) are accommodated within the process air channel (1), the condenser (5) being accommodated downstream of the evaporator (3) in a process air flow direction, wherein a compressor (4) of the heat pump (3, 4, 5) is accommodated downstream of the evaporator (3) within the process air channel (1). The invention is particularly useful for household appliances, in particular open-loop or closed-loop drying appliances.

Description

Clothes drying appliance

Technical Field

The present invention relates to a laundry drying appliance comprising a process air channel and a heat pump, wherein an evaporator and a condenser of the heat pump are accommodated within the process air channel. The invention is particularly useful for household appliances, in particular open-loop or closed-loop drying appliances.

Background

Laundry drying appliances using heat pumps are known. For example, EP 1964965 a1 discloses a household appliance comprising a drying chamber for drying wet articles in the drying chamber, a process air passage for circulating process air to dry the articles, and a heat pump. The heat pump includes a pumping passage containing a pumping fluid to be circulated through the pumping passage, an evaporator heat exchanger for transferring heat from process air into the pumping fluid by evaporating the pumping fluid, a liquefier heat exchanger for transferring heat from the pumping fluid to process air by liquefying the pumping fluid, a compressor for compressing the pumping fluid and driving the pumping fluid through the pumping passage, and a nozzle for depressurizing the pumping fluid.

As another example, EP 2253757 a1 discloses a household appliance having a housing and comprising within the housing a control unit, a drying chamber for accommodating articles to be dried, a closed-loop process air channel for conveying process air along the articles for drying having a first blower operable by the control unit, a heat pump unit operable by the control unit for extracting moisture from the process air, a condensate collector for collecting condensate formed there by the heat pump unit, and means for cooling at least one component of the heat pump unit, the means comprising a second blower operable by the control unit, the means for cooling includes an open-loop cooling channel having the second blower for conveying cooling air from outside the housing to the at least one component. Further, the cooling channel includes a guide including the second blower, the guide connecting an inlet in the housing to the at least one component for cooling. The housing has a plurality of outlets so that cooling air can flow out of the housing.

WO 2013/144875 a1 discloses a heat exchanger comprising at least one set of tubes, each set of tubes comprising at least two tubes, wherein the tubes are mechanically connected by at least one connecting structure. At least two tubes are made of different metals having different coefficients of thermal expansion; at least two of the pipes having different coefficients of thermal expansion are connected by a soldered or brazed connection. At the junction of the two tubes, a tube made of a metal having a lower coefficient of thermal expansion is embedded in a tube made of a metal having a higher coefficient of thermal expansion. The invention also relates to a household appliance, in particular a laundry treatment appliance, comprising at least one such heat exchanger, and to a method for manufacturing such a heat exchanger.

WO 2015/068092 a1 discloses a heat pump designed for a household appliance, in particular a laundry treatment appliance, comprising a rotary compressor, a condenser, a flow restrictor and an evaporator, wherein the condenser is of the expansion tube fin type, the outer diameter of the tube of which is less than 7mm, and wherein the ratio of the height to the radius of the rollers is between 1.4 and 1.2. A household appliance, in particular a laundry treatment appliance, comprises such a heat pump.

EP 2987904 a1 discloses a front-loading tumble dryer comprising a casing accommodating a rotatable drum comprising a rear wall having an inlet for process air and a heat pump comprising a condenser, wherein the condenser is at least partially arranged between the rear wall of the drum and the rear wall of the casing.

WO 2005/036079 a2 discloses a heat pump device comprising a heat pump cycle in which a refrigerant circulates through a compressor, a radiator, a throttle device and an evaporator in this order, and an air duct surrounding the radiator and the evaporator, by means of which air absorbed from an object to be dried is dehumidified, and by means of which the air is heated. The fairing is disposed at an inlet of the air duct.

EP 2341179 a1 discloses a domestic laundry dryer comprising an outer casing and, within the casing, a laundry drying container for receiving laundry to be dried and a hot-air generator for circulating a hot air flow within the laundry drying container; the hot-air generator is provided with a heat pump assembly having a refrigerant compression device connected to the supporting wall of the housing via one or more vibration dampers.

At present, heat pumps are usually implemented such that their components are arranged on a base module. The base module is a plastic structure that constitutes or is located on the bottom of the respective laundry drying appliance. When all the heat pump components (including, for example, the compressor, the heat exchanger, the piping for the working fluid (refrigerant), the capillary tube, and the dehumidifying filter) are assembled on top of the base module, the assembly may also be referred to as a bottom group. Currently, the position of the compressor on the bottom group is in the corner of the bottom group outside the air flow path. In another aspect, the heat exchanger is disposed within the airflow conductor. Furthermore, the compressor is arranged in a vertical manner, i.e. with its longitudinal axis oriented vertically or almost vertically. An additional fan is arranged in front of the compressor for cooling of the compressor.

Disclosure of Invention

It is an object of the present invention to at least partially overcome the problems associated with the prior art. A particular object of the present invention is to provide a laundry drying appliance comprising a heat pump with improved energy performance, particularly cost-effective and/or having a particularly compact design.

This object is achieved according to a feature of the present invention. Advantageous embodiments can be found, for example, in the solutions of the invention and/or in the description.

This object is achieved by a laundry drying appliance comprising a process air channel and a heat pump, wherein an evaporator and a condenser of the heat pump are accommodated within the process air channel, the condenser being accommodated downstream of the evaporator in a direction of process air flow, and wherein a compressor of the heat pump is accommodated downstream of the evaporator within the process air channel.

Typically, the condenser is arranged downstream of the evaporator. The evaporator serves to cool warm and humid process air flowing from a laundry container, such as a drum. The evaporator condenses moisture of the process air. Downstream of the evaporator, the resulting cooler and drier process air flows through a condenser where it is heated and then re-enters the laundry container as warm dry air.

Such a laundry drying appliance has the following advantages: the heat generated by operating the compressor may be used to directly heat the process air flowing around the compressor. This improves the energy performance of the heat pump dryer. This arrangement also improves the cooling of the compressor since the process air flowing around the compressor is relatively cool.

Thus, in one modification, there is an advantage that a dedicated fan for cooling the compressor can be omitted. This in turn has the advantage that space requirements and costs can be reduced. Smaller compressors can be used due to the improved energy performance.

Furthermore, the compressor is arranged closer to the heat exchanger, which position makes it possible to reduce the length of the working fluid conduit. This in turn enables a reduction in the amount of refrigerant and thus a reduction in cost.

Positioning the compressor in or inside the process air channel also has the following advantages: the space on the bottom group that is currently used for accommodating the compressor can be freely used for arranging other components. Furthermore, the arrangement of the compressor between the evaporator and the condenser makes the design particularly compact. The position between the evaporator and the condenser comprises a position in the flow path of the process air from the air outlet of the laundry compartment (e.g. drum) to the air inlet thereof. Thus, the laundry compartment is not located between the evaporator and the condenser. In addition, a position between the evaporator and the condenser corresponds to a structural position (structural position) of the compressor. The compressor may be located entirely between the evaporator and the condenser.

The compressor may be located entirely within the process air channel. Thereby, the compressor is completely immersed in the process air flow. This makes the temperature transfer between the compressor and the process air particularly efficient and thereby further improves the energy performance. Furthermore, a particularly compact design can be achieved. This embodiment may for example comprise: the main housing of the compressor, in which the working fluid is compressed, is located entirely within the process air channel.

The laundry drying appliance may be a laundry dryer or a combined washing/drying machine ("washer-dryer").

In addition to the evaporator, condenser and compressor, the heat pump also includes an expansion valve/capillary tube and a moisture removal filter, etc. The compressor may be a rotary compressor.

One embodiment is: a compressor is housed within the process air channel between the evaporator and the condenser.

One embodiment is: the compressor is a horizontal rotary compressor. This has the following advantages: the height of the compressor is lower than the height of the vertically oriented compressor and the compressor can be installed in a space that is not higher than, or at least not significantly higher than, the height of the heat exchanger. This in turn improves the air flow around the entire length of the compressor and thereby improves the effective heat transfer from the compressor to the process air. Thus, one advantageous embodiment is: the height of the compressor does not exceed the height of the heat exchanger.

A "horizontal rotary compressor" may be defined as a rotary compressor having a longitudinal axis that is more inclined or directed towards a horizontal plane relative to a vertical plane. Similarly, a "vertically oriented compressor" or vertical compressor may be defined as a compressor having a longitudinal axis that is more aligned with a vertical plane relative to a horizontal plane. The horizontal rotary compressor has similar performance to the vertical rotary compressor, and the working principle is the same. The difference between the vertical compressor and the horizontal compressor may exist at the location of the oil pumping system, the suction pipe/accumulator and/or the discharge pipe.

One embodiment is: the longitudinal axis of the compressor deviates by not more than 10 °, in particular by not more than 5 °, from the horizontal plane. This provides a particularly advantageous compact design.

One embodiment is: the compressor is oriented in alignment with the process air channel. This keeps the pressure loss caused by the compressor low. The orientation of the compressor in alignment with the process air channel may comprise an arrangement in which the longitudinal axis of the compressor is in the same vertical plane as the flow direction of the process air/the direction of the process air channel. This may include: the longitudinal axis of the compressor and the direction of flow of the process air/direction of the process air channel are aligned parallel when viewed from above.

Another embodiment is: the compressor is oriented transversely with respect to the process air channel. This makes the energy transfer particularly high. The transverse orientation of the compressor relative to the process air channel may comprise an arrangement in which a vertical plane comprising the longitudinal axis of the compressor and a vertical plane comprising the flow direction of the process air/the direction of the process air channel are perpendicular to each other. This may include: the longitudinal axis of the compressor is perpendicular to the flow direction of the process air/the direction of the process air channel, as seen from above.

Another embodiment is: the evaporator, compressor and condenser are components of the bottom group. This has the following advantages: the process air channel between them can be particularly short, thereby achieving a particularly compact design. Furthermore, only a small air pressure loss enables maintaining a fast flow of process air and thus achieving high energy performance. These advantages are even more pronounced in the case of embodiments in which the evaporator, compressor and condenser are part of the bottom group. In particular, the evaporator, the compressor and the condenser are components of the base module of the bottom group. This facilitates the assembly of the heat exchanger. If the laundry drying appliance comprises a laundry drum, the components of the bottom group are usually arranged below the drum.

Another embodiment is: the evaporator and the condenser are located at approximately the same height. This further contributes to making the process air channel between the evaporator and the condenser particularly short. Substantially the same height can be met when the evaporator and the condenser are located at the same height or have a vertical offset of less than half, in particular less than one quarter, of the height of the evaporator or the condenser, viewed horizontally along the process air channel.

Another embodiment is: the process air channel includes a tubular housing that houses an evaporator, a compressor, and a condenser. This has the following advantages: a particularly short and easy to manufacture process air channel is provided. The tubular housing may be shaped like a straight tube. The tubular housing may be oriented horizontally, i.e. the longitudinal axis of the tubular housing is oriented horizontally. The longitudinal axis of the tubular housing may coincide with the direction of the process air flow. In particular, between and including the evaporator and the condenser, the cross section of the tubular housing may have a substantially constant height, in particular a substantially constant cross section. The cross-section of the tubular housing may be circular, rectangular, square, etc.

One embodiment is: the evaporator is realized as a first finned tube heat exchanger and the condenser is realized as a second finned tube heat exchanger. The finned tube heat exchanger may be implemented such that a stack of fins is penetrated by a set of tubes. Such a heat exchanger is very compact and efficient. The fins serve as heat exchange structures for the tubes. In a finned tube heat exchanger, the tubes are preferably oriented in the same direction to achieve a particularly compact form. In particular, the heat exchanger may be a working fluid/process air heat exchanger comprising a set of pipes for transporting a working fluid of the heat pump.

One embodiment is: the tubes of at least one of the heat exchangers have at least one section of aluminum tubing (e.g., a tube and/or elbow section) and at least one section of copper tubing. Alternatively, the tube may be made entirely of copper or entirely of aluminum. The use of copper has the advantage of a particularly efficient heat transfer, which can be used to reduce the size (volume) of the heat exchanger while maintaining the amount of heat exchange. The use of aluminium has the advantage of a particularly cost-effective and lightweight heat exchanger. Furthermore, the use of copper enables the use of tube sections having a wall thickness that is less than the wall thickness of the aluminium tube sections. This can be used for pipe sections which also have a smaller outer diameter, which can lead to a particularly compact design. An advantageous embodiment is achieved when the outer diameter of the tube section is 5mm or less than 5 mm.

The same advantage is achieved if the fin pitch of at least one of the heat exchangers is less than 2.5 mm. Advantageously, the fin spacing is 2.2mm or less than 2.2mm, in particular 1.5mm or less than 1.5 mm. Smaller fin spacing increases the surface area available for exchanging heat, but results in higher flow resistance. Arranging the compressor between the heat exchangers has slowed the flow speed of the process air to the condenser so that the higher flow resistance caused by the denser fin arrangement of the condenser does not play a significant role. Thus, it is advantageous that the fin pitch of the evaporator is greater than the fin pitch of the condenser, since the flow rate of the process air to the evaporator is not reduced by the compressor. In particular, the fin pitch of the evaporator may be about 2.2mm and the fin pitch of the condenser may be about 1.5 mm.

However, in general, the fin pitch of the evaporator may be smaller than that of the condenser, or may have the same fin pitch.

One embodiment is: the dimension ("depth") of each heat exchanger along the process air channel is 70mm or less than 70 mm. This enables a variety of different compressors to be built between the heat exchangers while maintaining a compact design.

One embodiment is: the number of rows of linear tube sections of the condenser and of the evaporator along the process air channel is the same, whereas the number of linear tube sections of the condenser in the vertical direction is higher. This has the following advantages: the heat exchange capacity of the condenser may be greater than that of the evaporator while maintaining the same depth. For example, the condenser may use seven tubes per row, while the evaporator uses five tubes per row. This also results in a vertical height of the condenser of, for example, about 135mm being greater than a vertical height of the steamer of about 95 mm. Alternatively, the heat exchangers may have the same height but different depths, or the same height and the same depth but different numbers of tubes. For example, different tubes may be used.

One embodiment is: the appliance is a household appliance wherein the process air channel is part of a closed-loop process air path, the process air path further comprising a rotatable drum for accommodating laundry. The air outlet of the drum is connected to one end of a process air channel, and the other end of the process air channel is connected to the air inlet of the drum. The condenser is arranged downstream of the evaporator in the flow direction of the process air.

Alternatively, the appliance is a domestic appliance wherein the process air channel is part of an open-loop process air passage. In this case, the air inlet and the air outlet of the drum are connected to the surroundings. The air intake section arranged between the air intake opening of the air intake section and the air inlet of the drum may comprise a heat exchanger for heating the incoming ambient/fresh air, for example a condenser of a heat pump. The exhaust section between the air outlet of the drum and the exhaust opening to the surroundings can comprise a heat exchanger for cooling the outflowing warm and humid air, for example an evaporator of a heat pump.

In the case of an open loop process air path, a compressor may be arranged in the intake section between the condenser and the drum. Alternatively, the compressor may be arranged between the air intake opening of the air intake section and the condenser. Alternatively, a compressor may be arranged in the exhaust section between the evaporator and the exhaust opening to heat the air flow before sending it to the surroundings.

Drawings

The above-mentioned features and advantages of the invention and their type of realisation will now be schematically described in more detail by at least one embodiment in the context of one or more drawings.

Fig. 1 shows a top view of a section of a process air channel of a laundry drying appliance comprising an evaporator, a compressor and a condenser of a heat pump according to a first embodiment;

FIG. 2 shows a side view of the compressor of FIG. 1;

FIG. 3 shows a front view of the compressor of FIG. 2; and

fig. 4 shows a top view of a section of a process air channel of a laundry drying appliance comprising an evaporator, a compressor and a condenser of a heat pump according to a second embodiment.

Detailed Description

Fig. 1 shows a top view of a section of a process air channel 1 of a laundry drying appliance 2, said laundry drying appliance 2 comprising an evaporator 3, a compressor 4 and a condenser 5 of a heat pump 3 to 5 (expansion valves thereof are not shown). The compressor 4 is thereby accommodated in the process air channel 1 in the interspace between the evaporator 3 and the condenser 5. The evaporator 3 is embodied as a first finned-tube heat exchanger to transfer heat from the process air P to the working fluid of the heat pumps 3 to 5. The condenser 5 is embodied as a second finned tube heat exchanger to transfer heat from the working fluid of the heat pump 3 to 5 to the process air P. The components 1, 3 to 5 are fixed at the base module of a plastic bottom group (not shown).

As indicated by the arrows, the evaporator 3, the compressor 4 and the condenser 5 are arranged in sequence in the general flow direction of the process air P through the section. Within the process air channel 1, process air P flows from an exhaust opening of a laundry drum (not shown), e.g. a horizontally rotating drum, for receiving laundry to be dried, through an evaporator 3, along a compressor 4, through a condenser 5 and back into the drum through an intake opening. The movement of the process air P is caused by a fan (not shown). The condenser 5 is thus arranged downstream of the evaporator 3.

The evaporator 3 serves to cool warm and humid process air flowing from a laundry container, such as a drum. The evaporator 3 condenses moisture of the process air P. Thus, the process air P exiting the evaporator is relatively cool and dry. The process air P will be heated and reintroduced into the drum here to take away the moisture again from the wet laundry contained in the drum.

For this purpose, the process air P leaving the evaporator 3 flows here around the compressor 4. The compressor 4 has a warm exterior due to its operation as a driver of the heat pumps 3 to 5. Thereby, the process air P is heated due to the heat transfer from the compressor 4 to the process air P. The heated process air P then flows through the condenser 5 to be further heated. The now warm and dry process air P is then reintroduced into the drum.

The compressor 4 is a horizontal rotary compressor, as also shown in fig. 2. The horizontal rotary compressor 4 has an angle of 5 ° to the horizontal plane H

Of the longitudinal axis L. The horizontal rotary compressor 4 has a structure similar to that of the vertical compressor. As shown in fig. 3, the horizontal rotary compressor 4 has a suction duct 6 and a discharge duct 7 for the working fluid.

In laundry drying appliance 2, compressor 4 is oriented in alignment with process air channel 1. That is, if viewed from above, the longitudinal axis L of the compressor 4 and the flow direction of the process air P and the direction of the process air channel 1 are correspondingly aligned in parallel, as shown in fig. 1. This keeps the pressure loss caused by the presence of the compressor 4 low.

The fin pitch of the condenser 5 (e.g., 1.5mm) is smaller than the fin pitch of the evaporator 3 (e.g., 2.2mm) for high heat transfer effectiveness and low flow resistance.

For high heat transfer effectiveness, the tubes for conveying the working fluid of the evaporator 3 and/or the condenser 5 have at least one aluminum section and at least one copper section, either entirely made of copper or entirely made of aluminum. Preferably, the outer diameter of the tube is 5 mm. The tube thickness may be in the range of 0.2 to 0.25 mm.

In order to achieve a particularly compact design, the depth d of each

heat exchanger

3, 5 along the process air channel 1 is less than 70mm, for example approximately 65 mm. This can be achieved, for example, by setting the number of rows of linear tube sections (tubes) along the process air channel 1 to four or less for the evaporator 3 and the condenser 5. The number of linear tube sections in the vertical direction may vary, for example five for the evaporator 3 and seven for the condenser 5. This can translate into a vertical height of about 95mm for the evaporator 3 and about 135mm for the condenser 5.

The depth of the gap between the evaporator 3 and the condenser 5 may be between 200mm and 260mm, in particular between 220mm and 240mm, in particular about 230 mm.

Fig. 4 shows a top view of a section of the process air channel 1 of the laundry drying appliance 8. Laundry drying appliance 8 is similar to laundry drying appliance 1, with the difference that compressor 4 is here oriented transversely with respect to process air channel 1. The longitudinal axis L of the compressor 4 is therefore correspondingly perpendicular to the flow direction of the process air 1 and to the direction of the process air channel 1 in plan view. This orientation achieves a particularly high energy transfer.

Of course, the invention is not limited to the described embodiments.

For example, the laundry drying appliance may have an open loop air channel or air conduit. In this case, the compressor may be arranged after the condenser, i.e. downstream in the direction of the process air flow, or between the evaporator and the condenser. In any case, it is advantageous to house the compressor downstream of the evaporator in order to heat the process air before sending it back to the surroundings where it is taken.

List of reference numerals

1 process air channel

2 clothes drying appliance

3 evaporator

4 compressor

5 condenser

Suction pipeline of 6 compressor

7 discharge pipe of compressor

8 clothes drying appliance

d depth

H horizontal plane

L longitudinal axis

P treating air

Angle of rotation

Claims

1. Laundry drying appliance (2; 8) comprising a process air channel (1) and a heat pump (3, 4, 5), wherein-an evaporator (3) and a condenser (5) of the heat pump (3, 4, 5) are accommodated within the process air channel (1), the condenser (5) being accommodated downstream of the evaporator (3) in a process air flow direction, wherein-a compressor (4) of the heat pump (3-5) is accommodated within the process air channel (1) between the evaporator (3) and the condenser (5), and wherein-the compressor (4) is a horizontal rotary compressor; -the process air channel (1) comprises a tubular housing of straight tubes housing an evaporator (3), a compressor (4) and a condenser (5); -the evaporator (3) is realized as a first finned tube heat exchanger and the condenser (5) is realized as a second finned tube heat exchanger; -the fin pitch of the condenser (5) is smaller than the fin pitch of the evaporator (3); and-the number of rows of linear tube sections of the condenser (5) and the evaporator (3) along the process air channel (1) is the same, and the number of linear tube sections of the condenser (5) in the vertical direction is higher.

2. Laundry drying appliance (2; 8) according to claim 1, wherein the longitudinal axis (L) of the compressor (4) deviates not more than 5 ° with respect to the horizontal plane (H).

3. Laundry drying appliance (2) according to claim 2, wherein the compressor (4) is oriented in alignment with the process air channel (1).

4. Laundry drying appliance (8) according to claim 2, wherein the compressor (4) is oriented transversely with respect to the process air channel (1).

5. Laundry drying appliance (2; 8) according to any of the previous claims, wherein the evaporator (3), the compressor (4) and the condenser (5) are components of a bottom group.

6. Laundry drying appliance (2; 8) according to claim 5, wherein the evaporator (3), the compressor (4) and the condenser (5) are parts of a base module of the bottom group.

7. Laundry drying appliance (2; 8) according to any of claims 1-4, wherein the evaporator (3) and the condenser (5) are located at substantially the same height.

8. Laundry drying appliance (2; 8) according to any of claims 1-4, wherein: -the tube of at least one of the heat exchangers (3, 5) has at least one aluminium section and at least one copper section, either made entirely of copper or entirely of aluminium, -the tube has an outer diameter of 5mm or less than 5mm, and-the fin pitch of at least one of the heat exchangers is 2.5mm or less than 2.5 mm.

9. Laundry drying appliance (2; 8) according to any of claims 1-4, wherein the depth (d) of each of the evaporator (3) and the condenser (5) along the process air channel is 70mm or less than 70 mm.

10. Laundry drying appliance (2; 8) according to any of claims 1-4, wherein-the laundry drying appliance (2; 8) is a household appliance, wherein the process air channel (1) is part of a closed-loop process air channel, -the process air channel further comprises a rotatable drum for accommodating laundry, -an air outlet of the drum is connected to one end of the process air channel (1), -the other end of the process air channel (1) is connected to an air inlet of the drum, and-the condenser (5) is located downstream of the evaporator (3).

11. The laundry drying appliance of any one of claims 1-4, wherein: -the laundry drying appliance is a household appliance, wherein the process air channel is part of an open-loop process air channel, -the process air channel further comprises a rotatable drum for accommodating laundry, -an air intake section of the process air channel is arranged between an air intake opening of the section and an air intake of the drum, and comprises a condenser (5), -an air exhaust section of the process air channel is arranged between an air exhaust opening of the drum and an air exhaust of the section, and comprises an evaporator (3), -a compressor (4) is arranged in the air intake section between the condenser and the drum, or in the air intake section between the air intake opening and the condenser, or in the air exhaust section between the evaporator and the air intake opening.