Patent Application
20240240877
The present disclosure relates to a heat exchanger.
As disclosed in PTL 1 (Japanese Unexamined Patent Application Publication No. 2019-15410), there is known a heat exchanger in which heat transfer fins are inserted from a side of one ends in a longitudinal direction of cross sections of flat tubes.
A heat exchanger of one or more embodiments exchanges heat between a refrigerant and air. The heat exchanger includes a plurality of flat tubes, a plurality of first heat transfer fins, and a plurality of second heat transfer fins. The plurality of flat tubes are arranged in a first direction intersecting with a longitudinal direction of cross sections of the flat tubes, and the refrigerant flows through an inside of the flat tubes. The plurality of first heat transfer fins are inserted with respect to the plurality of flat tubes from a side of first ends in the longitudinal direction of the cross sections of the flat tubes. The plurality of first heat transfer fins are in contact with the plurality of flat tubes. The plurality of first heat transfer fins are located on a windward side. The plurality of second heat transfer fins are inserted with respect to the plurality of flat tubes from a side of second ends in the longitudinal direction of the cross sections of the flat tubes. The plurality of second heat transfer fins are in contact with the plurality of flat tubes. The plurality of second heat transfer fins are located on a leeward side. The first heat transfer fins each include a plurality of first insertion portions and a first connection portion. The plurality of first insertion portions each are inserted between adjacent ones of the flat tubes. The first connection portion connects the plurality of first insertion portions on an outer side of the first ends in the longitudinal direction of the cross sections of the flat tubes. The first connection portion extends in the first direction. The second heat transfer fins each include a plurality of second insertion portions and a second connection portion. The plurality of second insertion portions each are inserted between adjacent ones of the flat tubes. The second connection portion connects the plurality of second insertion portions on an outer side of the second ends in the longitudinal direction of the cross sections of the flat tubes. The second connection portion extends in the first direction.
An air conditioner 1 is an apparatus that performs air conditioning in a target space using a vapor compression refrigeration cycle.
The indoor unit 10 is installed in a target space to be air-conditioned, such as the inside of a room of a building in which the air conditioner 1 is installed. The indoor unit 10 is, for example, a wall-hooked unit or a ceiling-embedded unit. As illustrated in
The indoor heat exchanger 11 exchanges heat between a refrigerant flowing through the indoor heat exchanger 11 and air in the target space. The indoor heat exchanger 11 is, for example, a fin-and-tube heat exchanger including a plurality of heat transfer fins and a plurality of heat transfer tubes.
As illustrated in
The indoor fan 12 is a fan that supplies the air in the target space to the indoor heat exchanger 11. The indoor fan 12 is, for example, a cross-flow fan. As illustrated in
The indoor control unit 19 controls operations of components constituting the indoor unit 10.
The indoor control unit 19 is electrically connected with various devices included in the indoor unit 10, including the indoor fan motor 12m, so as to be able to transmit or receive control signals or information. The indoor control unit 19 is also communicably connected with the various sensors provided in the indoor unit 10.
The indoor control unit 19 includes a control calculation device and a storage device. The control calculation device is a processor such as a CPU or a GPU. The storage device is a storage medium such as a RAM, a ROM, and a flash memory. The control calculation device controls the operations of the components constituting the indoor unit 10 by reading a program stored in the storage device and performing predetermined calculation processing in accordance with the program. Moreover, the control calculation device can write a calculation result in the storage device or read information stored in the storage device in accordance with the program.
The indoor control unit 19 is configured to be able to receive various signals transmitted from an operation remote controller (not illustrated). The various signals include, for example, signals for instructing start and stop of an operation, and signals relating to various settings. The signals relating to the various settings include, for example, signals relating to a set temperature and a set humidity.
The indoor control unit 19 transmits or receives various signals and the like to or from an outdoor control unit 29 of the outdoor unit 20 via the communication line 80. The indoor control unit 19 and the outdoor control unit 29 cooperate with each other to function as a controller 60. The function of the controller 60 will be described later.
The outdoor unit 20 is installed, for example, outside a room such as a garden or a balcony of the building in which the air conditioner 1 is installed. As illustrated in
As illustrated in
The compressor 21 sucks the refrigerant with a low pressure, compresses the refrigerant using a compression mechanism (not illustrated), and discharges the compressed refrigerant. The compressor 21 is, for example, a rotary type or scroll type positive-displacement compressor. The compression mechanism of the compressor 21 is driven by a compressor motor 21m. The number of rotations of the compressor motor 21m can be controlled by an inverter.
The flow path switching valve 22 is a mechanism that switches the flow path of the refrigerant between a first state and a second state. In the first state, as indicated by solid lines in the flow path switching valve 22 in
The flow path switching valve 22 sets the flow path of the refrigerant to the first state during the cooling operation. In this case, the refrigerant discharged from the compressor 21 flows through the outdoor heat exchanger 24, the outdoor expansion valve 25, and the indoor heat exchanger 11 in this order in the refrigerant circuit 40, and returns to the compressor 21. In the first state, the outdoor heat exchanger 24 functions as a condenser, and the indoor heat exchanger 11 functions as an evaporator.
The flow path switching valve 22 sets the flow path of the refrigerant to the second state during the heating operation. In this case, the refrigerant discharged from the compressor 21 flows through the indoor heat exchanger 11, the outdoor expansion valve 25, and the outdoor heat exchanger 24 in this order in the refrigerant circuit 40, and returns to the compressor 21. In the second state, the outdoor heat exchanger 24 functions as an evaporator, and the indoor heat exchanger 11 functions as a condenser.
The accumulator 23 has a gas-liquid separation function of separating the refrigerant flowing therein into the gas refrigerant and the liquid refrigerant. The refrigerant flowing into the accumulator 23 is separated into the gas refrigerant and the liquid refrigerant, and the gas refrigerant collected in an upper space flows out to the compressor 21.
The outdoor heat exchanger 24 exchanges heat between the refrigerant flowing inside the outdoor heat exchanger 24 and outdoor air. The structure of the outdoor heat exchanger 24 will be described in detail later.
One end of the outdoor heat exchanger 24 is connected with the liquid refrigerant connection pipe 41 via the liquid refrigerant pipe 43d. The other end of the outdoor heat exchanger 24 is connected with the flow path switching valve 22 via the first gas refrigerant pipe 43c. During the cooling operation, the refrigerant flows into the outdoor heat exchanger 24 from the first gas refrigerant pipe 43c, and the outdoor heat exchanger 24 functions as a condenser of the refrigerant.
During the heating operation, the refrigerant flows into the outdoor heat exchanger 24 from the liquid refrigerant pipe 43d, and the outdoor heat exchanger 24 functions as an evaporator of the refrigerant.
The outdoor expansion valve 25 is a mechanism for adjusting the pressure and flow rate of the refrigerant flowing through the refrigerant circuit 40. The outdoor expansion valve 25 is, for example, an electronic expansion valve.
The outdoor fan 26 is a fan that supplies air to the outdoor heat exchanger 24. The outdoor fan 26 is, for example, a propeller fan. The outdoor fan 26 is driven by an outdoor fan motor 26m. The number of rotations of the outdoor fan motor 26m can be controlled by an inverter.
The outdoor control unit 29 controls operations of components constituting the outdoor unit 20.
The outdoor control unit 29 is electrically connected with various devices included in the outdoor unit 20, including the compressor motor 21m, the flow path switching valve 22, the outdoor expansion valve 25, and the outdoor fan motor 26m, so as to be able to transmit or receive control signals or information. The outdoor control unit 29 is also communicably connected with the various sensors provided in the outdoor unit 20.
The outdoor control unit 29 includes a control calculation device and a storage device. The control calculation device is a processor such as a CPU or a GPU. The storage device is a storage medium such as a RAM, a ROM, and a flash memory. The control calculation device controls the operations of the components constituting the outdoor unit 20 by reading a program stored in the storage device and performing predetermined calculation processing in accordance with the program. Moreover, the control calculation device can write a calculation result in the storage device or read information stored in the storage device in accordance with the program.
The outdoor control unit 29 transmits or receives various signals and the like to or from the indoor control unit 19 of the indoor unit 10 via the communication line 80. The indoor control unit 19 and the outdoor control unit 29 cooperate with each other to function as the controller 60. The function of the controller 60 will be described later.
The controller 60 is constituted by communicably connecting the indoor control unit 19 and the outdoor control unit 29 via the communication line 80. The controller 60 controls the entire operation of the air conditioner 1 by the respective control calculation devices of the indoor control unit 19 and the outdoor control unit 29 executing the programs stored in the respective storage devices.
The controller 60 controls the start and stop of an operation of the air conditioner 1 and operations of various devices of the air conditioner 1 based on measurement signals of the various sensors, commands received by the indoor control unit 19 from the operation remote controller, and the like. Further, the controller 60 can transmit information such as a current operation state and various notifications to the operation remote controller.
The controller 60 mainly performs the cooling operation and the heating operation.
The cooling operation is an operation of cooling the target space to a set temperature.
The controller 60 receives an instruction to start the cooling operation and an instruction of a set temperature from, for example, the operation remote controller. The controller 60 switches the flow path switching valve 22 to the first state. During the cooling operation, the flow path switching valve 22 causes the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 to flow into the outdoor heat exchanger 24. The outdoor heat exchanger 24 exchanges heat between the refrigerant and the outdoor air supplied by the outdoor fan 26. The refrigerant cooled by the outdoor heat exchanger 24 is decompressed by the outdoor expansion valve 25 and flows into the indoor heat exchanger 11. The indoor heat exchanger 11 exchanges heat between the refrigerant and the air in the target space supplied by the indoor fan 12. The refrigerant heated through heat exchange in the indoor heat exchanger 11 is sucked into the compressor 21 via the flow path switching valve 22 and the accumulator 23. The air in the target space cooled by the indoor heat exchanger 11 is blown from the indoor unit 10 to the target space, so that the target space is cooled.
The heating operation is an operation of heating the target space to a set temperature.
The controller 60 receives an instruction to start the heating operation and an instruction of a set temperature from, for example, the operation remote controller. The controller 60 switches the flow path switching valve 22 to the second state. During the heating operation, the flow path switching valve 22 causes the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 to flow into the indoor heat exchanger 11. The indoor heat exchanger 11 exchanges heat between the refrigerant and the air in the target space supplied by the indoor fan 12. The refrigerant cooled by the indoor heat exchanger 11 is decompressed by the outdoor expansion valve 25 and flows into the outdoor heat exchanger 24. The outdoor heat exchanger 24 exchanges heat between the refrigerant and the outdoor air supplied by the outdoor fan 26. The refrigerant heated through heat exchange in the outdoor heat exchanger 24 is sucked into the compressor 21 via the flow path switching valve 22 and the accumulator 23. The air in the target space heated by the indoor heat exchanger 11 is blown from the indoor unit 10 to the target space, so that the target space is heated.
As illustrated in
As illustrated in
As illustrated in
The flat tubes 243 are formed of aluminum or an aluminum alloy.
As illustrated in
As illustrated in
The first insertion portions 241a each have a rib 241c and a fin tab 241d. The rib 241c is formed by being bulged leftward in an angular C-like mountain shape. The fin tab 241d is formed by being cut and raised leftward. The fin tab 241d maintains an interval (fin pitch L11) between adjacent ones of the first heat transfer fins 241.
The first connection portion 241b has a rib 241e and a fin tab 241f. The rib 241e is formed by being bulged leftward in an angular C-like mountain shape. The fin tab 241f is formed by being cut and raised leftward. The fin tab 241f maintains an interval (fin pitch L11) between adjacent ones of the first heat transfer fins 241.
As illustrated in
As illustrated in
The second insertion portions 242a each have a rib 242c and a fin tab 242d. The rib 242c is formed by being bulged leftward in an angular C-like mountain shape. The fin tab 242d is formed by being cut and raised leftward. The fin tab 242d maintains an interval (fin pitch L21) between adjacent ones of the second heat transfer fins 242.
The second connection portion 242b has a rib 242e and a fin tab 242f. The rib 242e is formed by being bulged leftward in an angular C-like mountain shape. The fin tab 242f is formed by being cut and raised leftward. The fin tab 242f maintains an interval (fin pitch L21) between adjacent ones of the second heat transfer fins 242.
As illustrated in
In the present embodiments, the first heat transfer fin 241 and the second heat transfer fin 242 are formed of a clad material.
As illustrated in
During the cooling operation, the header 245 distributes the refrigerant flowing from the compressor 21 side through the first gas refrigerant pipe 43c into the outdoor heat exchanger 24 (in a direction of a solid line arrow in
In this verification, heating capacities of the outdoor heat exchanger 24 according to the present embodiments and an outdoor heat exchanger 50 of related art in which a plurality of heat transfer fins 51 are inserted from the leeward side were compared when the heating operation was performed at a low outdoor temperature.
As illustrated in
In the outdoor heat exchanger 50, the windward side of the flat tubes 52 is exposed, and there is no connection portion of the heat transfer fins 51 on the windward side of the flat tubes 52. Thus, dew condensation water cannot be properly drained, and frosting is likely to occur. Therefore, it is considered that the peak of the heating capacity of the outdoor heat exchanger 50 is lower than that of the outdoor heat exchanger 24, and the heating capacity of the outdoor heat exchanger 50 decreases more rapidly than that of the outdoor heat exchanger 24.
When a defrosting operation is performed at a proper timing in anticipation of a decrease in the heating capacity, the air conditioner 1 including the outdoor heat exchanger 24 of the present embodiments can reduce the frequency of the defrosting operation and extend the time during which the heating operation is performed, as compared to an air conditioner of related art including the outdoor heat exchanger 50, because frosting is delayed.
(5-1)
In related art, there is known a heat exchanger in which heat transfer fins are inserted from a side of one ends in a longitudinal direction of cross sections of flat tubes.
When a heating operation is performed at a low outdoor temperature, the heat exchanger of the related art does not include a connection portion of the heat transfer fins on a windward side or a leeward side, and hence dew condensation water cannot be properly drained and frosting is likely to occur.
An outdoor heat exchanger 24 of the present embodiments exchanges heat between a refrigerant and air. The outdoor heat exchanger 24 includes a plurality of flat tubes 243, a plurality of first heat transfer fins 241, and a plurality of second heat transfer fins 242. The plurality of flat tubes 243 are arranged in an up-down direction intersecting with a front-rear direction of cross sections S of the flat tubes 243. The refrigerant flows through an inside of the flat tubes 243. The plurality of first heat transfer fins 241 are inserted with respect to the plurality of flat tubes 243 from a rear side in the front-rear direction of the cross sections S of the flat tubes 243. The plurality of first heat transfer fins 241 are in contact with the plurality of flat tubes 243. The plurality of first heat transfer fins 241 are located on a windward side. The plurality of second heat transfer fins 242 are inserted with respect to the plurality of flat tubes 243 from a front side in the front-rear direction of the cross sections S of the flat tubes 243. The plurality of second heat transfer fins 242 are in contact with the plurality of flat tubes 243. The plurality of second heat transfer fins 242 are located on a leeward side. The first heat transfer fins 241 each include a plurality of first insertion portions 241a and a first connection portion 241b. The plurality of first insertion portions 241a each are inserted between adjacent ones of the flat tubes 243. The first connection portion 241b connects the plurality of first insertion portions 241a on an outer side of rear ends in the front-rear direction of the cross sections S of the flat tubes 243. The first connection portion 241b extends in the up-down direction. The second heat transfer fins 242 each include a plurality of second insertion portions 242a and a second connection portion 242b. The plurality of second insertion portions 242a each are inserted between adjacent ones of the flat tubes 243. The second connection portion 242b connects the plurality of second insertion portions 242a on an outer side of front ends in the front-rear direction of the cross sections S of the flat tubes 243. The second connection portion 242b extends in the up-down direction.
The first heat transfer fin 241 includes the first connection portion 241b. The first connection portion 241b connects the plurality of first insertion portions 241a on the outer side of the rear ends in the front-rear direction of the cross sections S of the flat tubes 243. The first connection portion 241b extends in the up-down direction. The second heat transfer fin 242 includes the second connection portion 242b. The second connection portion 242b connects the plurality of second insertion portions 242a on the outer side of the front ends in the front-rear direction of the cross sections S of the flat tubes 243. The second connection portion 242b extends in the up-down direction.
Consequently, since the outdoor heat exchanger 24 includes the first connection portion 241b of the first heat transfer fin 241 and the second connection portion 242b of the second heat transfer fin 242 on both sides of the flat tubes 243, the outdoor heat exchanger 24 can improve drainage performance and delay frosting.
(5-2)
In the outdoor heat exchanger 24 of the present embodiments, a distance L3 in an air flow direction between the first heat transfer fin 241 and the second heat transfer fin 242 is 1 mm or more and is 20% or less of a length L4 in the front-rear direction of the cross sections S of the flat tubes 243.
Consequently, the outdoor heat exchanger 24 can prevent an end portion on the windward side of the second heat transfer fin 242 from being closed by frosting and delay frosting.
(5-3)
In the outdoor heat exchanger 24 of the present embodiments, the first heat transfer fin 241 and the second heat transfer fin 242 are formed of a clad material.
Consequently, the outdoor heat exchanger 24 can ensure hydrophilicity of the first heat transfer fin 241 and the second heat transfer fin 242 and improve drainage performance.
In the present embodiments, the width L12 in the air flow direction of the first connection portion 241b is equal to the width L22 in the air flow direction of the second connection portion 242b. However, for example, the width L12 in the air flow direction of the first connection portion 241b may be larger than the width L22 in the air flow direction of the second connection portion 242b.
Consequently, the outdoor heat exchanger 24 can delay frosting of an end portion on the windward side of the first heat transfer fin 241 by locating the end portion on the windward side of the first heat transfer fin 241 away from the flat tubes 243.
In the present embodiments, the fin pitch L11 of the plurality of first heat transfer fins 241 is equal to the fin pitch L21 of the plurality of second heat transfer fins 242. However, for example, the fin pitch L11 of the plurality of first heat transfer fins 241 may be larger than the fin pitch L21 of the plurality of second heat transfer fins 242.
Consequently, the outdoor heat exchanger 24 can prevent the plurality of first heat transfer fins 241 from being closed by frosting and delay frosting.
In the present embodiments, the distance L3 in the air flow direction between the first heat transfer fin 241 and the second heat transfer fin 242 is 1 mm or more. However, for example, the distance L3 in the air flow direction between the first heat transfer fin 241 and the second heat transfer fin 242 may be equal to or more than the fin pitch L11 of the plurality of first heat transfer fins 241 and may be equal to or more than the fin pitch L21 of the plurality of second heat transfer fins 242.
Consequently, the outdoor heat exchanger 24 can prevent the end portion on the windward side of the second heat transfer fin 242 from being closed by frosting and delay frosting.
For example, the first heat transfer fin 241 and the second heat transfer fin 242 may have different fin shapes. For example, a waffle may be formed in the first heat transfer fin 241, and a louver or a slit may be formed in the second heat transfer fin 242.
Consequently, the outdoor heat exchanger 24 can separate the effects of the first heat transfer fin 241 and the second heat transfer fin 242, for example, by forming the first heat transfer fin 241 into a shape having a frosting delaying effect and forming the second heat transfer fin 242 into a shape having a heat transfer promoting effect.
For example, the first heat transfer fin 241 and the second heat transfer fin 242 may have cuts in different states. The state of a cut includes the presence or absence of the cut.
For example, a cut such as a louver or a slit may be formed in a front edge on the windward side of the second heat transfer fin 242.
Consequently, the outdoor heat exchanger 24 can promote heat transfer of the second heat transfer fin 242.
In the present embodiments, the position of the first heat transfer fin 241 and the position of the second heat transfer fin 242 are substantially aligned with each other in the front-rear direction. However, for example, the first heat transfer fin 241 and the second heat transfer fin 242 may be arranged in a staggered manner.
Consequently, the outdoor heat exchanger 24 can promote heat transfer of an edge portion on the windward side of the second heat transfer fin 242.
(6-8)
Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present disclosure. Accordingly, the scope of the disclosure should be limited only by the attached claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-162282 | Sep 2021 | JP | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/035752 | Sep 2022 | WO |
| Child | 18622224 | US |
