Patent Application
20250020409
The present disclosure relates to a heat exchanger having a water guide.
There is a parallel-flow heat exchanger in which flat tubes are located with an inclination to the vertical direction. This parallel-flow heat exchanger has been known as having such a configuration that a flat plate extending from the lowermost portion of an upper header to the flat tubes is provided to prevent condensate from scattering from the upper header (see, for example, Patent Literature 1).
Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2015-227754
In the heat exchanger disclosed in Patent Literature 1, the flat plate is simply attached to the upper header to cover the surface of the upper header. This may cause condensate to scatter from outside of the flat plate without being guided to the heat exchanger, and thus may cause dew dripping.
The present disclosure has been made in view of the above circumstances, and it is an object of the present disclosure to provide a heat exchanger that can prevent dew dripping of condensate from a header.
A heat exchanger according to an embodiment of the present disclosure includes: a plurality of heat transfer tubes, each of which extends in a first direction, arranged in a second direction orthogonal to the first direction; an upper header provided on an upper end of each of the plurality of heat transfer tubes and extending in the second direction; and a water guide covering a part of the upper header within a region of an angle formed by the first direction and a third direction orthogonal to the first direction and the second direction as viewed from a center of the upper header in the second direction, and guiding condensate generated on a surface of the upper header toward a position between the plurality of heat transfer tubes.
According to an embodiment of the present disclosure, the water guide covers a part of a lower portion of the upper header within the region of the angle formed by the first direction and the third direction, and can therefore guide condensate generated on the surface of the upper header toward the position between the plurality of heat transfer tubes.
Hereinafter, an air-conditioning apparatus according to an embodiment will be described with reference to the drawings. Note that the same constituent elements in the drawings are denoted by the same reference signs, and redundant explanation will be omitted appropriately. The present disclosure may include all combinations of configurations that can be combined among the configurations explained in each embodiment described below. In addition, the relationship of sizes of the components in the drawings may differ from that of actual ones. The forms of the constituent elements described throughout the entire specification are merely examples, and do not intend to limit the constituent elements to the forms described in the specification.
As illustrated in
The indoor unit 102 has the second heat exchanger 154. The second heat exchanger 154 is provided with the second refrigerant distributer 154a. The second refrigerant distributer 154a distributes refrigerant to heat transfer tubes (not illustrated) of the second heat exchanger 154. An indoor fan 157 is provided in the vicinity of the second heat exchanger 154.
The compressor 100, the first heat exchanger 152, and the expansion device 153 are connected by a pipe 155a, while the expansion device 153, the second heat exchanger 154, and the compressor 100 are connected by a pipe 155b, thereby forming the refrigerant circuit.
The compressor 100 is configured to compress suctioned refrigerant into a high-temperature and high-pressure state. The refrigerant compressed by the compressor 100 is discharged from the compressor 100 and delivered to the first heat exchanger 152 or the second heat exchanger 154.
The flow switching device 151 is configured to switch a flow of refrigerant between flow directions for heating operation and cooling operation. The flow switching device 151 switches the flow of refrigerant to a flow direction to connect the compressor 100 and the second heat exchanger 154 during heating operation, and switches the flow of refrigerant to a flow direction to connect the compressor 100 and the first heat exchanger 152 during cooling operation. Note that the flow switching device 151 is preferably a four-way valve. However, a combination of two-way valves or three-way valves may be employed as the flow switching device 151.
The first heat exchanger 152 serves as an evaporator during heating operation, and serves as a condenser during cooling operation. In the first heat exchanger 152 when the first heat exchanger 152 serves as an evaporator, low-temperature and low-pressure refrigerant flowing out from the expansion device 153 exchanges heat with air supplied by the outdoor fan 156, and liquid refrigerant of low-temperature and low-pressure two-phase gas-liquid refrigerant evaporates. In contrast, in the first heat exchanger 152 when the first heat exchanger 152 serves as a condenser, high-temperature and high-pressure refrigerant discharged from the compressor 100 exchanges heat with air supplied by the outdoor fan 156, and high-temperature and high-pressure gas refrigerant condenses. Note that the first heat exchanger 152 may be a refrigerant-water heat exchanger. In this case, in the first heat exchanger 152, refrigerant exchanges heat with a heat medium such as water.
The expansion device 153 is configured to expand refrigerant flowing out from the first heat exchanger 152 or the second heat exchanger 154, and to reduce the pressure of the refrigerant. The expansion device 153 is preferably an electrically operated expansion valve or another component that is capable of adjusting, for example, the flow rate of refrigerant. Note that as the expansion device 153, not only the electrically operated expansion valve, but a mechanical expansion valve or a capillary tube are also applicable. The mechanical expansion valve employs a diaphragm on its pressure receiving portion.
The second heat exchanger 154 serves as a condenser during heating operation, and serves as an evaporator during cooling operation. In the second heat exchanger 154 when the second heat exchanger 154 serves as a condenser, high-temperature and high-pressure refrigerant discharged from the compressor 100 exchanges heat with air supplied by the indoor fan 157, and high-temperature and high-pressure gas refrigerant condenses. In contrast, in the second heat exchanger 154 when the second heat exchanger 154 serves as an evaporator, low-temperature and low-pressure refrigerant flowing out from the expansion device 153 exchanges heat with air supplied by the indoor fan 157, and low-temperature and low-pressure liquid refrigerant of two-phase gas-liquid refrigerant evaporates. Note that the second heat exchanger 154 may be a refrigerant-water heat exchanger. In this case, in the second heat exchanger 154, refrigerant exchanges heat with a heat medium such as water.
The first refrigerant distributer 152a distributes refrigerant to a plurality of heat transfer tubes of the first heat exchanger 152. The outdoor fan 156 sends air to be used for exchanging heat to the first heat exchanger 152. The second refrigerant distributer 154a distributes refrigerant to heat transfer tubes (not illustrated) of the second heat exchanger 154. The indoor fan 157 sends air to be used for exchanging heat to the second heat exchanger 154.
The controller 160 controls the refrigeration cycle apparatus 200 in its entirety. Specifically, the controller 160 controls the driving frequency of the compressor 100 in response to the cooling capacity or heating capacity required. The controller 160 also controls the opening degree of the expansion device 153 in response to the operating condition and operating mode. The controller 160 further controls the flow switching device 151 in response to the operating mode.
In accordance with operating instructions from a user, the controller 160 uses information transmitted from each temperature sensor (not illustrated) and each pressure sensor (not illustrated) to control, for example, respective actuators of the compressor 100, the expansion device 153, and the flow switching device 151.
Note that the controller 160 may be hardware such as a circuit device that implements the functions of the controller 160, or may be made up of a computation device such as a microcomputer and a CPU, and software to be executed by the computation device.
The controller 160 is dedicated hardware or a central processing unit (CPU, also referred to as “central processor,” “processing device,” “computation device,” “microprocessor,” “microcomputer,” or “processor”) configured to execute programs stored in a memory. When the controller 160 is dedicated hardware, the controller 160 is equivalent to, for example, a single circuit, a combined circuit, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a combination of any of the foregoing. The functional units of the controller 160 may be individually implemented by separate units of hardware, or the functional units of the controller 160 may be implemented together by a single unit of hardware. When the controller 160 is a CPU, the functions to be executed by the controller 160 are implemented by software, firmware, or a combination of the software and the firmware. The software and the firmware are described as programs and stored in the memory. The CPU reads and executes the programs stored in the memory, thereby to implement the functions of the controller 160. For example, the memory is a nonvolatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, and an EEPROM. Note that the functions of the controller 160 may be partially implemented by dedicated hardware, while being partially implemented by software or firmware.
Note that while
Next, operation of the refrigeration cycle apparatus 200 is described along with a flow of refrigerant. Operation of the refrigeration cycle apparatus 200 in cooling mode is described below with reference to an example in which the first heat exchanger 152 and the second heat exchanger 154 use air as a heat exchange fluid. Note that the dotted arrows in
When the compressor 100 is driven, high-temperature and high-pressure refrigerant in gas form is discharged from the compressor 100. The high-temperature and high-pressure gas refrigerant (single phase) discharged from the compressor 100 flows into the first heat exchanger 152. The high-temperature and high-pressure gas refrigerant flowing in the first heat exchanger 152 exchanges heat with air supplied by the outdoor fan 156. This high-temperature and high-pressure gas refrigerant is condensed into high-pressure liquid refrigerant (single phase).
The high-pressure liquid refrigerant delivered from the first heat exchanger 152 is brought into a state of low-pressure two-phase gas-liquid refrigerant by the expansion device 153. The two-phase gas-liquid refrigerant is collected by the second refrigerant distributer 154a, and the collected two-phase gas-liquid refrigerant flows into the second heat exchanger 154. In the second heat exchanger 154, the two-phase gas-liquid refrigerant distributed by the second refrigerant distributer 154a and flowing into the second heat exchanger 154 exchanges heat with air supplied by the indoor fan 157. Liquid refrigerant of the two-phase gas-liquid refrigerant then evaporates into low-pressure single-phase gas refrigerant. The low-pressure gas refrigerant delivered from the second heat exchanger 154 flows into the compressor 100 through the accumulator 300, and is then compressed into high-temperature and high-pressure gas refrigerant to be discharged from the compressor 100 again. This cycle is repeated afterwards.
Note that operation of the refrigeration cycle apparatus 200 in heating mode is performed by switching the flow of refrigerant to the flow direction shown by the solid arrows in
It is also allowable that the refrigerant flows in a fixed direction, instead of providing the flow switching device 151 on the discharge side of the compressor 100.
In a case where the refrigeration cycle apparatus 200 is dedicated to cooling or heating and thus does not need to switch between flow directions of refrigerant, it is allowable that the flow switching device 151 is not provided.
Further, application examples of the refrigeration cycle apparatus 200 include, in addition to the air-conditioning apparatus, a hot-water supply device, a refrigerating machine, and an air-conditioning hot-water supply combination system.
While
As illustrated in
The flat tubes 3 extend in a first direction, which is the vertical direction (gravity direction). In Embodiment 1, the first direction is the vertical direction. In the drawings, a direction pointed by the arrow of the first direction corresponds to its positive direction.
The upper header 1 and the lower header 2 are located to extend in a second direction orthogonal to the first direction. The flat tubes 3 are spaced apart from each other in the second direction with their ends inserted into the upper header 1, and with their other ends inserted into the lower header 2. Although the flow direction of refrigerant is not particularly specified, the refrigerant flows from the lower header 2 toward the upper header 1 during evaporation operation in
The corrugated fins 4 are attached to the flat tubes 3 such that the corrugated fins 4 are each positioned between the corresponding adjacent ones of the flat tubes 3. The corrugated fins 4 extend in the second direction orthogonal to the first direction. The corrugated fins 4 transfer heat to the flat tubes 3. The corrugated fins 4 each have a louvered structure through which water can be discharged in the first direction. Note that the form of a fin to be attached to the flat tubes 3 is not limited to the corrugated fin.
When the second heat exchanger 154 is located in place, the drain pan 5 is located below the lower header 2. The drain pan 5 receives, on its upper surface, condensate that adheres to the surface of the upper header 1 and drops onto the drain pan 5 through the water guide 12.
The water guide 12 is provided to the upper header 1, and has a first water guide 11a and a second water guide 11b. The first water guide 11a and the second water guide 11b are formed as separate components of, for example, resin.
The first water guide 11a covers a part of the upper header 1 within a region of an angle formed by the first direction and a third direction orthogonal to the first direction and the second direction as viewed from a center C of the upper header 1 in the second direction. In the drawings, a direction pointed by the arrow of the third direction corresponds to its positive direction. The center C of the upper header 1 refers to the center of the cross-section of the flow passage of the upper header 1. The first water guide 11a guides condensate generated on the surface of the upper header 1 to the corrugated fins 4. The first water guide 11a is provided in front of the upper header 1 in the direction of airflow passing through the corrugated fins 4. While not being in contact with the corrugated fins 4, the first water guide 11a is located in the vicinity of the corrugated fins 4 such that the first water guide 11a guides the condensate to the corrugated fins 4.
The first water guide 11a covers the upper header 1 over the entire region of the angle formed by the first direction and the third direction orthogonal to the first direction and the second direction as viewed from the center C of the upper header 1 in the second direction. One end portion of the first water guide 11a positioned closer to the heat transfer tubes than is the other end portion is positioned on an imaginary line extending in the positive direction of the first direction, or in an area between the imaginary line and an imaginary line extending in the negative direction of the third direction as viewed from the center C of the upper header 1 in the second direction (see, for example,
The second water guide 11b covers a part of the upper header 1 within a region of an angle formed by the first direction and the third direction orthogonal to the first direction and the second direction as viewed from the center C of the upper header 1 in the second direction. The second water guide 11b guides condensate generated on the surface of the upper header 1 to the corrugated fins 4. The second water guide 11b is provided behind the upper header 1 in the direction of airflow passing through the corrugated fins 4. While not being in contact with the corrugated fins 4, the second water guide 11b is located in the vicinity of the corrugated fins 4 such that the second water guide 11b guides the condensate to the corrugated fins 4.
While the first water guide 11a and the second water guide 11b each have a substantially L-shape as illustrated in
Condensate generated on the surface of the upper header 1 is guided to the corrugated fins 4 by the first water guide 11a and the second water guide 11b. The condensate guided to the corrugated fins 4 exchanges heat with airflow passing through the corrugated fins 4, while being partially discharged in the first direction. The condensate discharged from the corrugated fins 4 runs down the surface of the flat tubes 3 and drops from the lower header 2 onto the drain pan 5.
In the second heat exchanger 154 in Embodiment 1, the water guide 12 allows condensate generated on the surface of the upper header 1 to be guided to the corrugated fins 4, so that it is possible to prevent the condensate from flowing out from the upper header 1 to an airflow path. As a result, it is possible to prevent drew dripping of condensate generated on the surface of the upper header 1.
In the second heat exchanger 154 in the modification of Embodiment 1, the first water guide 11a and the second water guide 11b are in contact with the corrugated fins 4 as illustrated in
In Embodiment 1, the second heat exchanger 154 has been described as being provided vertically. In Embodiment 2, the second heat exchanger 154 is located with an inclination to the vertical direction.
As illustrated in
The water guide 12 is provided to the upper header 1 and has the first water guide 11a. The first water guide 11a covers a part of the upper header 1 that faces in the direction in which the flat tube 3 is inclined, within a region of an angle formed by the first direction and the third direction orthogonal to the first direction and the second direction as viewed from the center C of the upper header 1 in the second direction. The first water guide 11a guides condensate generated on the surface of the upper header 1 to the corrugated fins 4. The first water guide 11a is provided in front of the upper header 1 in the direction of airflow passing through the corrugated fins 4. While not being in contact with the corrugated fins 4, the first water guide 11a is located in the vicinity of the corrugated fins 4 such that the first water guide 11a guides the condensate to the corrugated fins 4.
Similarly to Embodiment 1, the first water guide 11a may be in contact with the corrugated fins 4. In this case, the first water guide 11a is in contact with the uppermost part of the corrugated fins 4.
The first direction, which is the inclination direction of the flat tube 3 to the vertical direction, may be either inclined forward or inclined rearward with reference to the airflow direction. The flat tube 3 may be inclined at any angle.
Even in the case illustrated in
According to Embodiment 2, even when the second heat exchanger 154 is located with an inclination, the first water guide 11a still covers a lower part of the upper header 1, which is inclined. It is therefore possible to prevent condensate generated on the surface of the upper header 1 from dropping onto the airflow path passing through the corrugated fins 4.
The first water guide 11a covers the upper header 1 over the entire region of the angle formed by the first direction and the third direction orthogonal to the first direction and the second direction as viewed from the center C of the upper header 1 in the second direction. One end portion of the first water guide 11a positioned closer to the heat transfer tubes than is the other end portion is positioned on an imaginary line extending in the positive direction of the first direction, or in an area between the imaginary line and an imaginary line extending in the negative direction of the third direction as viewed from the center C of the upper header 1 in the second direction.
The first water guide 11a has such a comb-like shape that the contact position between the first water guide 11a and the corrugated fins 4 is located upstream of the center of the upper header 1 in the airflow direction. The first water guide 11a having such a comb-like shape as described above is used, so that condensate flowing on the water guide 12 is less likely to flow out to the downstream side of the airflow.
The first water guide 11a is provided to the upper header 1 of the heat exchanger 21a. The first water guide 11a covers a part of the upper header 1 of the heat exchanger 21a, that faces in the direction in which the flat tube 3 is inclined, within a region of an angle formed by the first direction and the third direction orthogonal to the first direction and the second direction as viewed from the center C of the upper header 1 of the heat exchanger 21a in the second direction. The first water guide 11a guides condensate generated on the surface of the upper header 1 of the heat exchanger 21a to the corrugated fins 4. The first water guide 11a also covers a part of the upper header 1 of the heat exchanger 21b, that faces in the direction in which the flat tube 3 is inclined, within a region of an angle formed by the first direction and the third direction orthogonal to the first direction and the second direction as viewed from the center C of the upper header 1 of the heat exchanger 21b in the second direction. The first water guide 11a guides condensate generated on the surface of the upper header 1 of the heat exchanger 21b to the corrugated fins 4.
In the second heat exchanger 154 according to Embodiment 3, the first water guide 11a is in contact with the corrugated fins 4, and thus allows condensate generated on the upper header 1 to be guided to the surface of the corrugated fins 4 more reliably.
The first water guide 11a has an L-shape in side view, and thus can close the airflow path passing through between the upper header 1 and the corrugated fins 4. As a result, it is possible to prevent formation of frost on the airflow path caused by moist air bypassing the corrugated fins 4.
In the second heat exchanger 154 according to the modification of Embodiment 3, a single unit of first water guide 11a is shared between the heat exchanger 21a and the heat exchanger 21b. Therefore, the number of first water guides 11a to be produced is reduced, and the production cost can be reduced accordingly.
In Embodiment 4, the surfaces of the first water guide 11a and the second water guide 11b in Embodiment 1 are water-repellent surfaces. In Embodiment 4, the surfaces of the first water guide 11a and the second water guide 11b in Embodiments 2 and 3 are water-repellent surfaces. In Embodiment 4, the surfaces of the corrugated fins 4 in Embodiments 1, 2, and 3 are hydrophilic surfaces.
Whether the surface is water-repellent or hydrophilic is determined by a contact angle θ.
A droplet has such properties that when a surface has a wettability gradient with which the contact angle θ changes, a driving force is generated, which causes the droplet to move from a water-repellent surface toward a hydrophilic surface. Therefore, according to Embodiment 4, condensate is more easily guided from the first water guide 11a or the second water guide 11b toward the corrugated fins 4.
As illustrated in
As illustrated in
In the second heat exchanger 154 according to Embodiment 5, the first water guide 11a is provided to extend toward the inter-row water guide holes 31. Therefore, in the second heat exchanger 154 according to Embodiment 5, it is possible to more efficiently discharge condensate, compared to when the condensate is discharged through a discharge path on the corrugated fins 4.
As illustrated in
In the case where the second heat exchanger 154 is located with an inclination and only the first water guide 11a is provided as described in Embodiment 2, the thermal-insulation treatment portion 41 is provided between the first water guide 11a and the upper header 1.
In the second heat exchanger 154 in Embodiment 6, the thermal-insulation treatment portions 41 are provided, so that when moist air touches the first water guide 11a and the second water guide 11b, the thermal-insulation treatment portions 41 can further prevent the moist air from being cooled by and condensed on the surface of the upper header 1.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/003484 | 1/31/2022 | WO |
