Patent Application
20250109866
The present disclosure relates to an air conditioning apparatus.
PTL 1 (U.S. Pat. No. 5,341,870) discloses an air conditioning apparatus including a Type A heat exchanger in which a plurality of heat-exchanging portions each formed by arranging a plurality of heat transfer tubes each having a bent portion in a direction orthogonal to planes including the heat transfer tubes are arranged in a direction in which an airflow flows.
An air conditioning apparatus according to a first aspect performs air conditioning operation. The air conditioning apparatus includes a heat exchanger. The heat exchanger includes a first heat-exchanging portion and a second heat-exchanging portion. The first heat-exchanging portion and the second heat-exchanging portion each include a plurality of flat tubes that are arranged in a first direction, inside of which refrigerant flows. The plurality of flat tubes each have two extending portions and a coupling portion.
The two extending portions extend in directions different from each other on a plane orthogonal to the first direction, when viewed in the first direction. The coupling portion couples the two extending portions to allow an angle formed between the directions in which the two extending portions extend to be smaller than 180 degrees, when viewed in the first direction.
A plurality of the extending portions arranged in the first direction of the first heat-exchanging portion form first tube rows. A plurality of the extending portions arranged in the first direction of the second heat-exchanging portion form second tube rows.
The second heat-exchanging portion is disposed adjacent to the first heat-exchanging portion to allow a plurality of the coupling portions and the second tube rows to be positioned between the two first tube rows of the first heat-exchanging portion.
The first heat-exchanging portion and the second heat-exchanging portion are coupled to each other via a coupling tube to allow a flow of the refrigerant to be in series.
An air conditioning apparatus 100 implements a vapor compression refrigeration cycle to perform air conditioning operation (specifically, cooling operation and heating operation) in a space that is subject to air conditioning. The space that is subject to air conditioning is, for example, a space in a building such as an office building, a commercial facility, or a residence. Note that the air conditioning apparatus is merely an example of a refrigerant cycle apparatus, and a heat exchanger according to the present disclosure may be used in another refrigerant cycle apparatus, such as a refrigerator, a freezer, a water heater, or a floor heater.
The air conditioning apparatus 100 mainly includes an air handling unit 1, a heat source unit 2, a liquid-refrigerant connection pipe 4, a gas-refrigerant connection pipe 5, and a control unit 3. The liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5 are connection pipes that couple the air handling unit 1 and the heat source unit 2 to each other. In the air conditioning apparatus 100, the air handling unit 1 and the heat source unit 2 are coupled to each other via the liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5 to form a refrigerant circuit 6.
The air handling unit 1 mainly includes a utilization heat exchanger 21 and a utilization fan 30. Details of the air handling unit 1 will be described later.
The heat source unit 2 mainly includes a compressor 2a, a four-way switching mechanism 2b, a heat-source heat exchanger 2c, an expansion mechanism 2d, a liquid-side shutoff valve 2e, a gas-side shutoff valve 2f, and a heat source fan 2g.
The heat source unit 2 includes a suction tube P1, a discharge tube P2, a first gas-refrigerant tube P3, a liquid-refrigerant tube P4, and a second gas-refrigerant tube P5, as refrigerant tubes for coupling various devices forming the refrigerant circuit 6. The suction tube P1 couples the four-way switching mechanism 2b and a suction side of the compressor 2a to each other. The discharge tube P2 couples a discharge side of the compressor 2a and the four-way switching mechanism 2b to each other. The first gas-refrigerant tube P3 couples the four-way switching mechanism 2b and a gas side of the heat-source heat exchanger 2c to each other. The liquid-refrigerant tube P4 couples a liquid side of the heat-source heat exchanger 2c and the liquid-side shutoff valve 2e to each other. The expansion mechanism 2d is provided to the liquid-refrigerant tube P4. The second gas-refrigerant tube P5 couples the four-way switching mechanism 2b and the gas-side shutoff valve 2f to each other.
The compressor 2a sucks refrigerant at low pressure in the refrigeration cycle from the suction tube P1, compresses the refrigerant with a compression mechanism thereof (not illustrated), and discharges the refrigerant to the discharge tube P2.
The four-way switching mechanism 2b is a mechanism that switches a direction of the flow of the refrigerant to change a state of the refrigerant circuit 6 between a state of cooling operation and a state of heating operation. When the refrigerant circuit 6 is in the state of cooling operation, the heat-source heat exchanger 2c functions as a radiator (a condenser) for the refrigerant, and the utilization heat exchanger 21 functions as an evaporator for the refrigerant. When the refrigerant circuit 6 is in the state of heating operation, the heat-source heat exchanger 2c functions as the evaporator for the refrigerant, and the utilization heat exchanger 21 functions as the condenser for the refrigerant.
When the four-way switching mechanism 2b sets the state of the refrigerant circuit 6 to the state of cooling operation, the four-way switching mechanism 2b causes the suction tube P1 to communicate with the second gas-refrigerant tube P5, and causes the discharge tube P2 to communicate with the first gas-refrigerant tube P3 (see solid lines inside the four-way switching mechanism 2b illustrated in
The heat-source heat exchanger 2c causes the refrigerant flowing inside and a heat source (for example, air at and around an installation location of the heat source unit 2) to exchange heat.
The expansion mechanism 2d adjusts a pressure and a flow rate of the refrigerant flowing through the liquid-refrigerant tube P4.
The liquid-side shutoff valve 2e is a valve provided at a coupling portion between the liquid-refrigerant tube P4 and the liquid-refrigerant connection pipe 4. The gas-side shutoff valve 2f is a valve provided at a coupling portion between the second gas-refrigerant tube P5 and the gas-refrigerant connection pipe 5. The liquid-side shutoff valve 2e and the gas-side shutoff valve 2f are opened while the air conditioning apparatus 100 is operating.
The heat source fan 2g supplies external air serving as a heat source to the heat-source heat exchanger 2c.
The control unit 3 controls operation of various devices forming the air conditioning apparatus 100.
As illustrated in
The control unit 3 is implemented by a computer. The control unit 3 includes a control computation device and a storage device (both are not illustrated). The control computation device is a processor such as a central processing unit (CPU) or a graphics processing unit (GPU). The control computation device reads a program stored in the storage device and performs predetermined image processing and predetermined computation processing in accordance with the program. In addition, the control computation device writes a result of computation to the storage device and reads information stored in the storage device in accordance with the program.
The control unit 3 controls operation of the various devices forming the air conditioning apparatus 100, as described below. Thus, the air conditioning apparatus 100 performs cooling operation and heating operation.
When start of cooling operation is instructed through the remote controller or the like, the control unit 3 controls operation of the four-way switching mechanism 2b to switch the state of the refrigerant circuit 6 to a state in which the heat-source heat exchanger 2c functions as the radiator (the condenser) for the refrigerant and the utilization heat exchanger 21 functions as the evaporator for the refrigerant. Specifically, the control unit 3 controls operation of the four-way switching mechanism 2b to cause the suction tube P1 coupled to the suction side of the compressor 2a to communicate with the second gas-refrigerant tube P5 coupling the four-way switching mechanism 2b and the gas-side shutoff valve 2f to each other. Furthermore, the control unit 3 controls operation of the four-way switching mechanism 2b to cause the discharge tube P2 coupled to the discharge side of the compressor 2a to communicate with the first gas-refrigerant tube P3 coupling the four-way switching mechanism 2b and the gas side of the heat-source heat exchanger 2c to each other (see the solid lines inside the four-way switching mechanism 2b illustrated in
As the control unit 3 controls operation of the various devices in the air conditioning apparatus 100 in this way, the gas refrigerant at low pressure in the refrigeration cycle is sucked into the compressor 2a, compressed to have high pressure in the refrigeration cycle, and then discharged from the compressor 2a. The gas refrigerant at high pressure, which has been discharged from the compressor 2a, is sent to the heat-source heat exchanger 2c through the four-way switching mechanism 2b. The gas refrigerant at high pressure, which has been sent to the heat-source heat exchanger 2c, exchanges heat with air that serves as a cooling source, which is supplied by the heat source fan 2g, to radiate heat in the heat-source heat exchanger 2c functioning as the radiator for the refrigerant, and becomes the liquid refrigerant at high pressure. The liquid refrigerant at high pressure, which has radiated heat in the heat-source heat exchanger 2c, is sent to the expansion mechanism 2d through the liquid-refrigerant tube P4. In the expansion mechanism 2d, the liquid refrigerant at high pressure is decompressed to become the refrigerant at low pressure in a gas-liquid two-phase state. The refrigerant at low pressure in the gas-liquid two-phase state, which has been decompressed in the expansion mechanism 2d, is sent to the utilization heat exchanger 21 through the liquid-refrigerant tube P4, the liquid-side shutoff valve 2e, and the liquid-refrigerant connection pipe 4. The refrigerant at low pressure in the gas-liquid two-phase state, which has been sent to the utilization heat exchanger 21, exchanges heat with air supplied by the utilization fan 30 and evaporates in the utilization heat exchanger 21 functioning as the evaporator for the refrigerant. At this time, the air that has exchanged heat with the refrigerant and has thus been cooled is supplied to the space that is subject to air conditioning, cooling the space that is subject to air conditioning. The gas refrigerant at low pressure, which has been evaporated in the utilization heat exchanger 21, is again sucked into the compressor 2a through the gas-refrigerant connection pipe 5, the gas-side shutoff valve 2f, and the four-way switching mechanism 2b.
When start of heating operation is instructed through the remote controller or the like, the control unit 3 controls operation of the four-way switching mechanism 2b to switch the state of the refrigerant circuit 6 to a state in which the heat-source heat exchanger 2c functions as the evaporator for the refrigerant and the utilization heat exchanger 21 functions as the radiator (the condenser) for the refrigerant. Specifically, the control unit 3 controls operation of the four-way switching mechanism 2b to cause the suction tube P1 to communicate with the first gas-refrigerant tube P3 and to cause the discharge tube P2 to communicate with the second gas-refrigerant tube P5 (see the broken lines in the four-way switching mechanism 2b illustrated in
As the control unit 3 controls operation of the various devices in the air conditioning apparatus 100 in this way, the gas refrigerant at low pressure in the refrigeration cycle is sucked into the compressor 2a, compressed to have high pressure in the refrigeration cycle, and then discharged from the compressor 2a. The gas refrigerant at high pressure, which has been discharged from the compressor 2a, is sent to the utilization heat exchanger 21 through the four-way switching mechanism 2b, the gas-side shutoff valve 2f, and the gas-refrigerant connection pipe 5. The gas refrigerant at high pressure, which has been sent to the utilization heat exchanger 21, exchanges heat with air supplied by the utilization fan 30 to radiate heat in the utilization heat exchanger 21 functioning as the radiator (the condenser) for the refrigerant, and becomes the liquid refrigerant at high pressure. At this time, the air that has exchanged heat with the refrigerant and has thus been heated is supplied to the space that is subject to air conditioning, heating the space that is subject to air conditioning. The liquid refrigerant at high pressure, which has radiated heat in the utilization heat exchanger 21, is sent to the expansion mechanism 2d through the liquid-refrigerant connection pipe 4, the liquid-side shutoff valve 2e, and the liquid-refrigerant tube P4. The refrigerant sent to the expansion mechanism 2d is decompressed by the expansion mechanism 2d to become the refrigerant at low pressure in the gas-liquid two-phase state. The refrigerant at low pressure in the gas-liquid two-phase state, which has been decompressed by the expansion mechanism 2d, is sent to the heat-source heat exchanger 2c through the liquid-refrigerant tube P4. The refrigerant at low pressure in the gas-liquid two-phase state, which has been sent to the heat-source heat exchanger 2c, exchanges heat with air that serves as a heating source, which is supplied by the heat source fan 2g, to evaporate in the heat-source heat exchanger 2c functioning as the evaporator for the refrigerant, and becomes the gas refrigerant at low pressure. The refrigerant at low pressure, which has evaporated in the heat-source heat exchanger 2c, is again sucked into the compressor 2a through the four-way switching mechanism 2b.
The air handling unit 1 includes a casing 11, a support member 12, a heat-exchanging unit 20, and the utilization fan 30. As illustrated in
A blow-out port 13 is formed on an upper surface 11a of the casing 11. A suction port 14 is formed on a lower surface 11b of the casing 11. A blow-out duct 15 is coupled above the blow-out port 13. A suction duct 16 is coupled below the suction port 14. The blow-out port 13 is coupled to the blow-out duct 15 and the air-blowing chamber 18. The suction port 14 is coupled to the suction duct 16 and the heat-exchanging chamber 17. The heat-exchanging chamber 17 is in communication with the air-blowing chamber 18.
The utilization fan 30 includes a suction port 30a, a blow-out port 30b, a centrifugal fan such as a sirocco fan, and a motor for driving the centrifugal fan. As the centrifugal fan is driven, and air flowing into from the suction port 30a is blown out of the blow-out port 30b, the utilization fan 30 generates an airflow a representing a flow of air heading from the suction port 14 of the casing 11 toward the blow-out port 13 via the heat-exchanging chamber 17 and the air-blowing chamber 18. The airflow a flows upward in the vertical direction in the internal space of the casing 11 from the suction port 14 toward the blow-out port 13. The utilization heat exchanger 21 is installed at a position at which the airflow a flowing into the suction port 30a of the utilization fan 30 passes. When passing through the heat-exchanging chamber 17, air carried by the airflow a exchanges heat in the heat-exchanging unit 20. The air handling unit 1 sucks air from the suction port 14, and blows out air having exchanged heat in the heat-exchanging unit 20 for adjustment in temperature from the blow-out port 13. The air blown out of the blow-out port 13 is sent to the space that is subject to air conditioning via a duct (not illustrated). The utilization fan 30 is an example of a blowing device.
The heat-exchanging unit 20 includes the utilization heat exchanger 21 and a drain pan 22.
The utilization heat exchanger 21 causes the refrigerant and air carried by the airflow a generated by the utilization fan 30 to exchange heat. The utilization heat exchanger 21 includes a plurality of flat tubes 211, heat transfer fins 212, headers 213 and 214, a first coupling tube 215, and two second coupling tubes 216. The utilization heat exchanger 21 is coupled to the refrigerant circuit 6 via the liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5. The utilization heat exchanger 21 is a Type A heat exchanger including a heat-exchanging portion formed by arranging a plurality of heat transfer tubes each having a bent portion in a direction orthogonal to planes including the heat transfer tubes. The utilization heat exchanger 21 is an example of a heat exchanger.
The plurality of flat tubes 211 are heat transfer tubes for which aluminum or an aluminum alloy is used as a raw material, inside of which the refrigerant flows. As illustrated in
The flat tubes 211 each have one first portion 211a, one second portion 211b, and one coupling portion 211c. The first portion 211a and the second portion 211b extend in directions different from each other on a plane orthogonal to the first direction D1, when viewed in the first direction D1. As illustrated in
One end portion of the first portion 211a is coupled to the header 213. The other end portion of the first portion 211a is coupled to the coupling portion 211c. One end portion of the second portion 211b is coupled to the header 214. The other end portion of the second portion 211b is coupled to the coupling portion 211c.
The plurality of flat tubes 211 are disposed to allow the coupling portions 211c to be positioned above the headers 213 and 214 in the vertical direction. In other words, the first portions 211a and the second portions 211b are disposed to allow the end portions lying opposite to the coupling portions 211c to be positioned below the coupling portions 211c in the vertical direction. Therefore, as illustrated in
Each of the first portion 211a and the second portion 211b is a flat multi-hole tube having a plurality of passages (not illustrated) through which the refrigerant passes. The plurality of passages in the first portion 211a are disposed adjacent to each other in a direction orthogonal to the direction in which the first portion 211a extends, when viewed in the first direction D1. The plurality of passages in the second portion 211b are disposed in adjacent to each other in a direction orthogonal to the direction in which the second portion 211b extends, when viewed in the first direction D1.
The coupling portion 211c is a flat multi-hole tube coupling the first portion 211a and the second portion 211b to each other and having a plurality of passages (not illustrated) that allow the plurality of passages in the first portion 211a and the plurality of passages in the second portion 211b to communicate with each other. As illustrated in
For purposes of convenience, a direction in which a bisecting line L of an angle formed between the direction in which the first portion 211a extends and the direction in which the second portion 211b extends is hereinafter referred to as a second direction D2. Furthermore, a direction orthogonal to the bisecting line L, when viewed in the first direction D1, is hereinafter referred to as a third direction D3. In the present embodiment, the second direction D2 is in parallel to the vertical direction. In other words, the second direction D2 is in parallel to a direction in which the airflow a generated by the utilization fan 30 flows. The third direction D3 is in parallel to the horizontal direction. The third direction is a direction orthogonal to the first direction D1 and the second direction D2.
As illustrated in
The heat transfer fins 212 facilitate exchanging of heat between the refrigerant flowing inside the flat tubes 211 and air carried by the airflow a generated by the utilization fan 30. The heat transfer fins 212 are corrugated fins. For the heat transfer fins 212, aluminum or an aluminum alloy is used as a raw material.
As illustrated in
The utilization heat exchanger 21 includes a first heat-exchanging portion 41 and a second heat-exchanging portion 42. The first heat-exchanging portion 41 and the second heat-exchanging portion 42 each include the plurality of the flat tubes 211, the heat transfer fins 212, one of the headers 213, and one of the headers 214.
For purposes of convenience, a tube row formed by a plurality of the first portions 211a of the first heat-exchanging portion 41, which are arranged in the first direction D1, is hereinafter referred to as a first tube row 41a, and a tube row formed by a plurality of the second portions 211b of the first heat-exchanging portion 41, which are arranged in the first direction D1, is hereinafter referred to as a first tube row 41b. Furthermore, a tube row formed by a plurality of the first portions 211a of the second heat-exchanging portion 42, which are arranged in the first direction D1, is hereinafter referred to as a second tube row 42a, and a tube row formed by a plurality of the second portions 211b of the second heat-exchanging portion 42, which are arranged in the first direction D1, is hereinafter referred to as a second tube row 42b.
As illustrated in
A plurality of the coupling portions 211c and the second tube rows 42a and 42b of the second heat-exchanging portion 42 are positioned between the two first tube rows 41a and 41b of the first heat-exchanging portion 41. Furthermore, the first tube row 41a of the first heat-exchanging portion 41 and the second tube row 42a of the second heat-exchanging portion 42 are disposed adjacent to each other in directions orthogonal to the directions in which the first portions 211a of the first heat-exchanging portions 41 or the second heat-exchanging portions 42 extend, when viewed in the first direction D1. Similarly, the first tube row 41b of the first heat-exchanging portion 41 and the second tube row 42b of the second heat-exchanging portion 42 are disposed adjacent to each other in directions orthogonal to the directions in which the second portions 211b of the first heat-exchanging portions 41 or the second heat-exchanging portions 42 extend, when viewed in the first direction D1.
With such disposition to be in such a positional relationship as described above, the second heat-exchanging portion 42 is disposed to allow the two second tube rows 42a are 42b to be respectively positioned upwind of the different first tube rows 41a are 41b. Specifically, the second tube row 42a is disposed upwind of the first tube row 41a, and the second tube row 42b is disposed upwind of the first tube row 41b. Thus, the airflow a flowing in the second direction D2 is able to smoothly flow toward the first tube rows 41a and 41b after passing through the second tube rows 42a and 42b.
Note that the first tube row 41a and the second tube row 42a may be disposed to be in parallel to each other, or may be disposed to be not in parallel to each other, when viewed in the first direction D1. Similarly, the first tube row 41b and the second tube row 42b may be disposed to be in parallel to each other, or may be disposed to be not in parallel to each other, when viewed in the first direction D1.
The headers 213 and the headers 214 are respectively coupled to the respective ends of the plurality of flat tubes 211.
More specifically, the headers 213 are coupled to the first portions 211a of the plurality of flat tubes 211. The headers 214 are coupled to the second portions 211b of the plurality of flat tubes 211. The headers 213 and the headers 214 are disposed to extend in the first direction D1. The headers 213 and the headers 214 are positioned above the drain pan 22.
For purposes of convenience, one of the headers 213, which couples the end portions of the first portions 211a of the first heat-exchanging portion 41, which are positioned on the side opposite to the coupling portions 211c, to each other is hereinafter referred to as a first header 213a, and one of the headers 214, which couples the end portions of the second portions 211b of the first heat-exchanging portion 41, which are positioned on the side opposite to the coupling portions 211c, to each other is hereinafter referred to as a first header 214a. Furthermore, the other one of the headers 213, which couples the end portions of the first portions 211a of the second heat-exchanging portion 42, which are positioned on the side opposite to the coupling portions 211c, to each other is hereinafter referred to as a second header 213b, and the other one of the headers 214, which couples the end portions of the second portions 211b of the second heat-exchanging portion 42, which are positioned on the side opposite to the coupling portions 211c, to each other is hereinafter referred to as a second header 214b. When it is not necessary to distinguish the headers from each other, the headers are referred to as the headers 213 and the headers 214.
The first heat-exchanging portion 41 and the second heat-exchanging portion 42 are coupled to each other via the first coupling tube 215 to allow a flow of the refrigerant to be in series. Note herein that “allowing a flow of the refrigerant to be in series” means that the refrigerant that has passed through either one of the first heat-exchanging portion 41 and the second heat-exchanging portion 42 and has flowed out flows into the other one of the first heat-exchanging portion 41 and the second heat-exchanging portion 42 via the first coupling tube 215. The first coupling tube 215 is an example of a coupling tube.
Details of the coupling between the first heat-exchanging portion 41 and the second heat-exchanging portion 42 and the first coupling tube 215 will be described later.
The second coupling tubes 216 couple the liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5 to the utilization heat exchanger 21 to each other. More specifically, one ends of the second coupling tubes 216 are coupled to respective end portions, in the first direction D1, of the first header 213a and the second header 213b. Furthermore, the other ends of the second coupling tubes 216 are respectively coupled to the liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5.
Details of the coupling of the liquid-refrigerant connection pipe 4 and the gas-refrigerant connection pipe 5 to the second coupling tubes 216 will be described later.
The drain pan 22 receives dew condensation water from the utilization heat exchanger 21. The dew condensation water is water generated on surfaces of the plurality of flat tubes 211, the heat transfer fins 212, the headers 213, and the headers 214 through exchanging of heat between the refrigerant flowing inside the plurality of flat tubes 211 and air passing through the heat-exchanging chamber 17. The generated dew condensation water flows down along the surfaces of the plurality of flat tubes 211, the heat transfer fins 212, the headers 213, and the headers 214 by its own weight, and is received by the drain pan 22. The drain pan 22 is fixed to the support member 12.
The dew condensation water received by the drain pan 22 is discharged as drain water from a drain outlet 22a provided to the drain pan 22.
The first coupling tube 215 couples the first heat-exchanging portion 41 and the second heat-exchanging portion 42 to each other to allow, in heating operation of the air conditioning apparatus 100, the refrigerant flowing through the first heat-exchanging portion 41 and the refrigerant flowing through the second heat-exchanging portion 42 to form counter flows with respect to the airflow a flowing toward the first heat-exchanging portion 41 and the second heat-exchanging portion 42.
The first coupling tube 215 couples one of the first headers 213a and 214a and one of the second headers 213b and 214b to each other, which are provided to either a pair of the first tube row 41a and the second tube row 42a or a pair of the first tube row 41b and the second tube row 42b, which are arranged in the direction (the second direction D2) in which the airflow a flows. Furthermore, each of the other one of the first headers 213a and 214a and the other one of the second headers 213b and 214b, which are not coupled to each other via the first coupling tube 215, functions as an inlet portion or an outlet portion for the refrigerant to or from the first portion 211a and the second portion 211b.
Specifically, in the air conditioning apparatus 100, the first coupling tube 215 couples the first header 214a of the first heat-exchanging portion 41 and the second header 214b of the second heat-exchanging portion 42 to each other. The liquid-refrigerant connection pipe 4 is coupled to the second header 213b of the second heat-exchanging portion 42 via one of the second coupling tubes 216. Furthermore, the gas-refrigerant connection pipe 5 is coupled to the first header 213a of the first heat-exchanging portion 41 via the other one of the second coupling tubes 216. Thus, in heating operation, the refrigerant sent to the utilization heat exchanger 21 flows in a route indicated by linear arrows illustrated in
In heating operation, the gas refrigerant at high pressure, which has been sent from the heat source unit 2 through the gas-refrigerant connection pipe 5, flows into the first heat-exchanging portion 41 from the first header 213a. The refrigerant that has passed through the plurality of flat tubes 211 of the first heat-exchanging portion 41 passes through the first header 214a and the first coupling tube 215 in this order, and then flows into the second heat-exchanging portion 42 from the second header 214b. The refrigerant that has passed through the plurality of flat tubes 211 of the second heat-exchanging portion 42 flows into the liquid-refrigerant connection pipe 4 via the second header 213b, and is sent again to the heat source unit 2.
As described above, the gas refrigerant at high pressure, which has flowed into the utilization heat exchanger 21, exchanges heat with air in the space that is subject to air conditioning, which has been supplied by the utilization fan 30, to radiate heat in the utilization heat exchanger 21. At this time, the airflow a generated by the utilization fan 30 flows from a lower side toward an upper side in the vertical direction, that is, in the second direction D2, toward the utilization heat exchanger 21, as illustrated by a white arrow illustrated in
The air conditioning apparatus 100 is an air conditioning apparatus that performs air conditioning operation. The air conditioning apparatus 100 includes the utilization heat exchanger 21. The utilization heat exchanger 21 includes the first heat-exchanging portion 41 and the second heat-exchanging portion 42. The first heat-exchanging portion 41 and the second heat-exchanging portion 42 each include the plurality of flat tubes 211 that are arranged in the first direction D1, inside of which the refrigerant flows. The plurality of flat tubes 211 each have the first portion 211a, the second portion 211b, and the coupling portion 211c.
The first portion 211a and the second portion 211b extend in directions different from each other on a plane orthogonal to the first direction D1, when viewed in the first direction D1. The coupling portion 211c couples the first portion 211a and the second portion 211b to each other to allow the angle α or β formed between the direction in which the first portion 211a extends and the direction in which the second portion 211b extends, to be smaller than 180 degrees, when viewed in the first direction D1. The coupling portion 211c may couple the first portion 211a and the second portion 211b to each other to allow the angle α or β to be 90 degrees or smaller, when viewed in the first direction D1.
The plurality of first portions 211a and the plurality of second portions 211b arranged in the first direction D1 of the first heat-exchanging portion 41 form the first tube rows 41a and 41b. The plurality of first portions 211a and the plurality of second portions 211b arranged in the first direction D1 of the second heat-exchanging portion 42 form the second tube rows 42a and 42b.
The second heat-exchanging portion 42 is disposed adjacent to the first heat-exchanging portion 41 to allow the plurality of coupling portions 211c and the second tube rows 42a and 42b to be positioned between the two first tube rows 41a and 41b of the first heat-exchanging portion 41.
The first heat-exchanging portion 41 and the second heat-exchanging portion 42 are coupled to each other via the first coupling tube 215 to allow a flow of the refrigerant to be in series.
Since, in the utilization heat exchanger 21, the first heat-exchanging portion 41 and the second heat-exchanging portion 42 are coupled to each other via the first coupling tube 215 to allow a flow of the refrigerant to be in series, it is sufficient that the refrigerant be allowed to flow into either one of the first heat-exchanging portion 41 and the second heat-exchanging portion 42. Therefore, it is not necessary to cause the flow of the refrigerant to branch before flowing into the utilization heat exchanger 21, suppressing a decrease in flow rate of the inflow refrigerant due to branching and generation of a drift current along with this decrease. Therefore, with the air conditioning apparatus 100, a decrease in heat exchange efficiency due to a drift current of the inflow refrigerant in the utilization heat exchanger 21 is suppressed.
The first coupling tube 215 couples the first heat-exchanging portion 41 and the second heat-exchanging portion 42 to each other to allow, in the predetermined air conditioning operation, the refrigerant flowing through the first heat-exchanging portion 41 and the refrigerant flowing through the second heat-exchanging portion 42 to form counter flows with respect to the airflow a flowing toward the first heat-exchanging portion 41 and the second heat-exchanging portion 42.
With the air conditioning apparatus 100, the refrigerant flowing through the first heat-exchanging portion 41 and the refrigerant flowing through the second heat-exchanging portion 42 form counter flows with respect to the airflow a flowing toward the first heat-exchanging portion 41 and the second heat-exchanging portion 42, making it possible to achieve high heat exchange efficiency in the utilization heat exchanger 21.
The first heat-exchanging portion 41 further includes the two first headers 213a and 214a that couple the end portions of the plurality of first portions 211a and the plurality of second portions 211b forming the first tube rows 41a and 41b to each other, the end portions lying on the side opposite to the coupling portions 211c. The second heat-exchanging portion 42 further includes the two second headers 213b and 214b that couple the end portions of the plurality of first portions 211a and the plurality of second portions 211b forming the second tube rows 42a and 42b to each other, the end portions lying on the side opposite to the coupling portions 211c.
The second heat-exchanging portion 42 is disposed to allow the two second tube rows 42a and 42b to be respectively positioned upwind of the different first tube rows 41a and 41b.
The first coupling tube 215 couples one of the first headers 213a and 214a and one of the second headers 213b and 214b to each other, the one of the first headers and the one of the second headers being provided to either one of pairs of the first tube rows 41a and 41b and the second tube rows 42a and 42b, the pairs being arranged in the direction in which the airflow a flows. Each of an other one of the first headers 213a and 214a and an other one of the second headers 213b and 214b, the other one of the first headers and the other one of the second headers being not coupled to each other via the first coupling tube 215, functions as an inlet portion or an outlet portion for the refrigerant to or from the first portion 211a and the second portion 211b.
With the air conditioning apparatus 100, it is possible to achieve counter flows through simple processing for coupling the predetermined headers 213 and 214 to each other using the first coupling tube 215.
The first portion 211a and the second portion 211b are disposed to allow the end portions lying on the side opposite to the coupling portions 211c to be positioned vertically below the coupling portions 211c.
With the air conditioning apparatus 100, the headers 213 and 214, one of which functions as an inlet portion or an outlet portion, are positioned vertically below the plurality of flat tubes 211, suppressing accumulation of refrigerating machine oil contained in the refrigerant in the utilization heat exchanger 21.
The utilization heat exchanger 21 is disposed at a position at which the airflow flowing into the utilization fan 30 passes.
With the air conditioning apparatus 100, the airflow a generated by the utilization fan 30 passes through the utilization heat exchanger 21 in a uniform state, securing heat exchange efficiency in the utilization heat exchanger 21.
The first coupling tube 215 in the air conditioning apparatus 100, according to Modification Example A, couples the first heat-exchanging portion 41 and the second heat-exchanging portion 42 to each other to allow, in cooling operation by the air conditioning apparatus 100, the refrigerant flowing through the first heat-exchanging portion 41 and the refrigerant flowing through the second heat-exchanging portion 42 to form counter flows with respect to an airflow flowing toward the first heat-exchanging portion 41 and the second heat-exchanging portion 42.
Specifically, in the air conditioning apparatus 100 according to Modification Example A, the first coupling tube 215 couples the first header 214a of the first heat-exchanging portion 41 and the second header 214b of the second heat-exchanging portion 42 to each other, similar to the first embodiment. On the other hand, the liquid-refrigerant connection pipe 4 is coupled to the first header 213a of the first heat-exchanging portion 41 via one of the second coupling tubes 216. Furthermore, the gas-refrigerant connection pipe 5 is coupled to the second header 213b of the second heat-exchanging portion 42 via the other one of the second coupling tubes 216. Thus, in cooling operation, the refrigerant sent to the utilization heat exchanger 21 flows through a route indicated by linear arrows illustrated in
In cooling operation, the refrigerant at low pressure in the gas-liquid two-phase state, which has been sent from the heat source unit 2 through the liquid-refrigerant connection pipe 4, flows from the first header 213a into the first heat-exchanging portion 41. The refrigerant, which has passed through the plurality of flat tubes 211 of the first heat-exchanging portion 41, passes through the first header 214a and the first coupling tube 215 in this order, and then flows into the second heat-exchanging portion 42 from the second header 214b. The refrigerant, which has passed through the plurality of flat tubes 211 of the second heat-exchanging portion 42, flows into the gas-refrigerant connection pipe 5 via the second header 213b, and is sent again to the heat source unit 2.
As described above, the refrigerant at low pressure in the gas-liquid two-phase state, which has flowed into the utilization heat exchanger 21, exchanges heat with air in the space that is subject to air conditioning, which has been supplied by the utilization fan 30, and evaporates in the utilization heat exchanger 21. At this time, an airflow generated by the utilization fan 30 flows from the lower side toward the upper side in the vertical direction, that is, in the second direction D2, toward the utilization heat exchanger 21, as illustrated by the white arrow in
As illustrated in
The branching portion 215a has one inlet portion 215aa and two outlet portions 215ab. The branching portion 215a causes the refrigerant flowed from the inlet portion 215aa to branch into two flows and causes the refrigerant to flow out of the outlet portions 215ab. The inlet portion 215aa is coupled to the first header 214a. The refrigerant flowing out of the first heat-exchanging portion 41 flows into the inlet portion 215aa. The outlet portions 215ab are coupled to end portions on both sides, in the first directions D1, of the second header 214b, and communicate with the second heat-exchanging portion 42. The inlet portion 215aa is provided vertically below the outlet portions 215ab.
The refrigerant that has flowed out of the first heat-exchanging portion 41 through the first header 214a flows into the branching portion 215a from the inlet portion 215aa. The refrigerant that has been caused to branch by the branching portion 215a passes through the outlet portions 215ab and flows into the second header 214b from the end portions on both the sides.
The branching portion 215a causes the refrigerant flowing from the first heat-exchanging portion 41 into the second heat-exchanging portion 42 to branch, suppressing generation of a drift current in the second heat-exchanging portion 42. Therefore, with the air conditioning apparatus 100 according to Modification Example B, a decrease in heat exchange efficiency due to a drift current of the refrigerant flowing into the second heat-exchanging portion 42 is also suppressed.
Furthermore, the inlet portion 215aa is provided vertically below the outlet portions 215ab, improving branching performance of the branching portion 215a, compared with a case where the inlet portion 215aa is not provided vertically below the outlet portions 215ab. Thus, with the air conditioning apparatus 100 according to Modification Example B, a decrease in heat exchange efficiency due to a drift current of the refrigerant flowing into the second heat-exchanging portion 42 is effectively suppressed.
The air handling unit 1 may be installed horizontally.
The heat-exchanging unit 20 and the utilization fan 30 may be arranged to allow the airflow a to flow downward in the vertical direction in the internal space of the casing 11.
The heat-exchanging chamber 17 may be disposed above the air-blowing chamber 18.
An air conditioning apparatus 100a according to a second embodiment will now be described herein. Differences from the first embodiment will now be mainly described hereinafter, and description of identical or corresponding features will be omitted. The differences between the air conditioning apparatus 100 and the air conditioning apparatus 100a are coupling between the first heat-exchanging portion 41 and the second heat-exchanging portion 42 and the tubes.
A first coupling tube 215 in the air conditioning apparatus 100a couples the first heat-exchanging portion 41 and the second heat-exchanging portion 42 to each other to allow the refrigerant flowing through the first heat-exchanging portion 41 and the refrigerant flowing through the second heat-exchanging portion 42 to flow in parallel to each other.
The first coupling tube 215 couples one of the first headers 213a and 214a and one of the second headers 213b and 214b to each other, which are provided to either a pair of the first tube row 41a and the second tube row 42b or a pair of the first tube row 41b and the second tube row 42a, which are not arranged in the direction in which the airflow flows (the second direction D2). Furthermore, each of the other one of the first headers 213a and 214a and the other one of the second headers 213b and 214b, which are not coupled to each other via the first coupling tube 215, functions as an inlet portion or an outlet portion for the refrigerant to or from the first portion 211a and the second portion 211b.
Specifically, in the air conditioning apparatus 100a, the first coupling tube 215 couples the first header 213a of the first heat-exchanging portion 41 and the second header 214b of the second heat-exchanging portion 42 to each other. The liquid-refrigerant connection pipe 4 is coupled to the second header 213b of the second heat-exchanging portion 42 via one of the second coupling tubes 216. Furthermore, the gas-refrigerant connection pipe 5 is coupled to the first header 214a of the first heat-exchanging portion 41 via the other one of the second coupling tubes 216. Thus, in cooling operation by the air conditioning apparatus 100a, the refrigerant sent to the utilization heat exchanger 21 flows through a route illustrated by linear arrows illustrated in
In cooling operation, the refrigerant at low pressure in the gas-liquid two-phase state, which has been sent from the heat source unit 2 through the liquid-refrigerant connection pipe 4, flows into the second heat-exchanging portion 42 from the second header 213b. The refrigerant that has passed through the plurality of flat tubes 211 of the second heat-exchanging portion 42 passes through the second header 214b and the first coupling tube 215 in this order, and then flows into the first heat-exchanging portion 41 from the first header 213a. The refrigerant that has passed through the plurality of flat tubes 211 of the first heat-exchanging portion 41 flows into the gas-refrigerant connection pipe 5 via the first header 214a, and is sent again to the heat source unit 2. Thus, in cooling operation by the air conditioning apparatus 100a, the refrigerant flowing through the first heat-exchanging portion 41 and the refrigerant flowing through the second heat-exchanging portion 42 flow in parallel to each other.
Although a direction in which the refrigerant flows in heating operation is opposite to that in cooling operation, the refrigerant flowing through the first heat-exchanging portion 41 and the refrigerant flowing through the second heat-exchanging portion 42 flow in parallel to each other also in heating operation.
The first coupling tube 215 couples the first heat-exchanging portion 41 and the second heat-exchanging portion 42 to each other to allow the refrigerant flowing through the first heat-exchanging portion 41 and the refrigerant flowing through the second heat-exchanging portion 42 to flow in parallel to each other.
A temperature of the refrigerant that has flowed into the utilization heat exchanger 21 that functions as the evaporator initially drops due to pressure loss that occurs inside the flat tubes 211, but rises due to advancement of excessive heating after completion of evaporation. Therefore, in the utilization heat exchanger 21 functioning as the evaporator, a low-temperature region appears around a central portion in a direction in which the refrigerant flows.
In the utilization heat exchanger 21, the first coupling tube 215 is positioned at a substantially center in the direction in which the refrigerant flows. Therefore, in cooling operation in the utilization heat exchanger 21 in the air conditioning apparatus 100 according to Modification Example A, a lower-temperature region easily appears around the first header 214a of the first heat-exchanging portion 41 and the second header 214b of the second heat-exchanging portion 42, which the first coupling tube 215 couples to each other. As a result, a larger amount of dew condensation water is generated around the second portion 211b of the first heat-exchanging portion 41 and the second portion 211b of the second heat-exchanging portion 42, than in other regions.
As illustrated in
On the other hand, in the utilization heat exchanger 21 in the air conditioning apparatus 100a, the first coupling tube 215 couples the first header 213a of the first heat-exchanging portion 41 and the second header 214b of the second heat-exchanging portion 42 to each other. As a result, a larger amount of dew condensation water is generated around the first portion 211a of the first heat-exchanging portion 41 and the second portion 211b of the second heat-exchanging portion 42, than in other regions.
As illustrated in
The second heat-exchanging portion 42 is disposed to allow the two second tube rows 42a and 42b to be respectively positioned upwind of the different first tube rows 41a and 41b. The first coupling tube 215 couples one of the first headers 213a and 214a and one of the second headers 213b and 214b to each other, which are provided to either one of pairs of the first tube rows 41a and 41b and the second tube rows 42a and 42b, which are not arranged in the direction in which the airflow a flows. Each of an other one of the first headers 213a and 214a and an other one of the second headers 213b and 214b, which are not coupled to each other via the first coupling tube 215, functions as an inlet portion or an outlet portion for the refrigerant to or from the first portion 211a and the second portion 211b.
With the air conditioning apparatus 100a, scattering of dew condensation water is suppressed through simple processing for coupling the predetermined headers 213 and 214 to each other using the first coupling tube 215.
While the embodiments of the present disclosure have been described above, it will be understood that various modifications in form and detail may be made therein without departing from the spirit and scope of the present disclosure as set forth in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-170895 | Sep 2023 | JP | national |
This non-provisional application claims priority under 35 U.S.C. § 119 (a) to Patent Application No. JP 2023-170895, filed in Japan on Sep. 29, 2023, all of which are hereby expressly incorporated by reference into the present application.
