Heat exchanger and refrigeration device

Abstract

Provided is a heat exchanger that suppresses leakage of a refrigerant when water freezes and expands in volume. A heat exchanger is a heat exchanger that causes heat exchange between water and a refrigerant, and includes a first flow path through which the water flows, a second flow path through which the refrigerant flows, partition walls, a first separation member, and a second separation member. The partition walls separate the first flow path and the second flow path from each other. The first separation member is disposed at an end edge of the first flow path and configured to separate two adjacent ones of the partition walls from each other. The second separation member is disposed at an end edge of the second flow path and configured to separate two adjacent ones of the partition walls from each other. The first separation member is made of a material different from a material of the second separation member and / or has a shape different from a shape of the second separation member.

Description

Technical Field

[0001] The present disclosure relates to a heat exchanger and a refrigeration apparatus.Background Art

[0002] There has been known a plate-type heat exchanger in which a plurality of heat transfer plates are stacked at a predetermined interval to alternately form a flow path through which a first fluid flows and a flow path through which a second fluid flows in a stacking direction, and heat is exchanged between the two fluids.

[0003] In the plate-type heat exchanger, when a refrigerant and water are used as the fluids, the heat transfer plates may rupture when the water freezes and expands in volume, and the refrigerant may leak. PTL 1 (Japanese Unexamined Patent Application Publication No. 10-132476) discloses, as a fifth embodiment, a heat exchanger including heat transfer plates capable of absorbing stress by elastic deformation to suppress damage even when water freezes and expands in volume.Summary of InventionTechnical Problem

[0004] Even with the heat transfer plates disclosed in PTL 1, the stress absorbable range (elastically deformable range) is limited. Thus, damage to the heat transfer plates cannot be sufficiently suppressed, meaning that there is a risk of refrigerant leakage.

[0005] The present disclosure provides a heat exchanger and a refrigeration apparatus that suppress leakage of a refrigerant to the outside when water freezes and expands in volume.Solution to Problem

[0006] A heat exchanger of a first aspect is a heat exchanger that causes heat exchange between water and a refrigerant, and includes a first flow path through which the water flows, a second flow path through which the refrigerant flows, partition walls, a first separation member, and a second separation member. The partition walls separate the first flow path and the second flow path from each other. The first separation member is disposed at an end edge of the first flow path and configured to separate two adjacent ones of the partition walls from each other. The second separation member is disposed at an end edge of the second flow path and configured to separate two adjacent ones of the partition walls from each other. The first separation member is made of a material different from a material of the second separation member and / or has a shape different from a shape of the second separation member.

[0007] In the present heat exchanger, when the water flowing through the first flow path freezes and expands in volume, the first separation member ruptures before the second separation member ruptures. Therefore, according to the present heat exchanger, rupturing of the second separation member due to freezing of the water flowing through the first flow path is suppressed, and thus leakage of the refrigerant flowing through the second flow path to the outside of the heat exchanger is suppressed.

[0008] A heat exchanger of a second aspect is the heat exchanger of the first aspect, wherein the material of the first separation member has a smaller Young's modulus than the material of the second separation member.

[0009] The first separation member made of a material with a Young's modulus smaller than the material of the second separation member ruptures before the second separation member ruptures when the water flowing through the first flow path freezes and expands in volume. Therefore, according to the present heat exchanger, rupturing of the second separation member due to freezing of the water flowing through the first flow path is suppressed, and thus leakage of the refrigerant flowing through the second flow path to the outside of the heat exchanger is suppressed.

[0010] A heat exchanger of a third aspect is the heat exchanger of the second aspect, wherein the material of the first separation member is copper or aluminum. The material of the second separation member is SUS.

[0011] A heat exchanger of a fourth aspect is the heat exchanger of the first aspect, wherein the first separation member has a recessed portion, recessed toward the first flow path, formed on an outer surface.

[0012] When the water flowing through the first flow path freezes and expands in volume, the first separation member having a recessed portion ruptures before the second separation member ruptures, due to stress concentrated on the recessed portion. Therefore, according to the present heat exchanger, rupturing of the second separation member due to freezing of the water flowing through the first flow path is suppressed, and thus leakage of the refrigerant flowing through the second flow path to the outside of the heat exchanger is suppressed.

[0013] A heat exchanger of a fifth aspect is the heat exchanger of the first aspect, wherein a width of the first separation member is smaller than a width of the second separation member.

[0014] Since the width of the first separation member is smaller than the width of the second separation member, when the first flow path and the second flow path are under the same pressure, a larger stress acts on a joining portion between the first separation member and the partition wall than on a joining portion between the second separation member and the partition wall. Therefore, when the water flowing through the first flow path freezes and expands in volume, the joining portion between the first separation member and the partition wall ruptures before the joining portion between the second separation member and the partition wall ruptures. Therefore, according to the present heat exchanger, rupturing of the second separation member due to freezing of the water flowing through the first flow path is suppressed, and thus leakage of the refrigerant flowing through the second flow path to the outside of the heat exchanger is suppressed.

[0015] A heat exchanger of a sixth aspect is the heat exchanger of the fifth aspect, wherein a joining portion of the second separation member with the partition wall includes a portion overlapping the first flow path as viewed in a stacking direction.

[0016] A heat exchanger of a seventh aspect is the heat exchanger of the sixth aspect, wherein the width of the first separation member is not more than 1 / 2 of the width of the second separation member.

[0017] A heat exchanger of an eighth aspect is the heat exchanger of the first aspect, wherein the first separation member and the second separation member are joined to the partition walls using diffusion joining.

[0018] A heat exchanger of a ninth aspect is the heat exchanger of any one of the first to the eighth aspects, wherein the refrigerant is flammable or toxic.

[0019] In the present heat exchanger, even when a flammable or toxic refrigerant is used, leakage of the refrigerant from the heat exchanger is suppressed.

[0020] A refrigeration apparatus of a tenth aspect includes the heat exchanger of any one of the first to the ninth aspects.Brief Description of Drawings

[0021] [Fig. 1] Fig. 1 is a schematic configuration diagram illustrating a refrigeration apparatus 1 including a heat exchanger 100. [Fig. 2] Fig. 2 is a perspective view of the heat exchanger 100. [Fig. 3] Fig. 3 is an enlarged view of a portion A in Fig. 2. [Fig. 4] Fig. 4 is a cross-sectional view illustrating first inner fins 110 accommodated in the heat exchanger 100. [Fig. 5] Fig. 5 is a cross-sectional view illustrating second inner fins 120 accommodated in the heat exchanger 100. [Fig. 6] Fig. 6 is a cross-sectional view of the heat exchanger 100 taken along line B-B' in Fig. 3. [Fig. 7] Fig. 7 is a cross-sectional view of a heat exchanger 100 according to Modification A. [Fig. 8] Fig. 8 is a cross-sectional view of a heat exchanger 100 according to Modification B. Description of Embodiments(1) Refrigeration apparatus 1

[0022] First, a refrigeration apparatus 1 including a heat exchanger 100 according to an embodiment of the present disclosure will be described. The refrigeration apparatus 1 heats or cools water supplied from the outside of the refrigeration apparatus 1, such as city water (tap water), and supplies the water. The refrigeration apparatus 1 includes a water intake unit 1a, a water supply unit 1b, the heat exchanger 100, a refrigerant circuit 10, a water circuit 20, a water supply unit 30, and a control unit 40. Although not limited thereto, in the present embodiment, the water supply unit 30 is installed indoors, and the water circuit 20 and the refrigerant circuit 10 are installed outdoors. As will be described in detail below, a refrigerant circulates in the refrigerant circuit 10, and water circulates in the water circuit 20.

[0023] The water intake unit 1a takes in water supplied from the outside into the refrigeration apparatus 1. The water supply unit 1b supplies to the outside, water heated or cooled in the refrigeration apparatus 1.(1-1) Heat exchanger 100

[0024] The heat exchanger 100 causes heat exchange between the refrigerant circulating in the refrigerant circuit 10 and the water circulating in the water circuit 20. The heat exchanger 100 includes first flow pipes 170a and 170b, second flow pipes 180a and 180b, a first flow path 111, and a second flow path 121.

[0025] The first flow path 111 is a flow path through which the water flows. The first flow path 111 is provided between the first flow pipe 170a and the first flow pipe 170b.

[0026] The second flow path 121 is a flow path through which the refrigerant flows. The second flow path 121 is formed between the second flow pipe 180a and the second flow pipe 180b. A detailed structure of the heat exchanger 100 will be described below.(1-2) Refrigerant circuit 10

[0027] In the refrigerant circuit 10, the refrigerant is heated or cooled. The refrigerant circuit 10 includes a compressor 11, a four-way switching valve 12, a heat source heat exchanger 13, an expansion valve 14, and the second flow path 121 of the heat exchanger 100. The compressor 11, the four-way switching valve 12, the heat source heat exchanger 13, the expansion valve 14, and the second flow path 121 of the heat exchanger 100 are connected by pipes, and the refrigerant circulates therein. In the present embodiment, the refrigerant is propane.

[0028] The compressor 11 takes in a low-pressure refrigerant in the refrigerant circuit 10 through an intake portion 11a, compresses the refrigerant, and discharges the refrigerant as a high-pressure refrigerant through a discharge portion 11b.

[0029] The four-way switching valve 12 has a first port P1, a second port P2, a third port P3, and a fourth port P4. The four-way switching valve 12 is switched between a first state and a second state different from each other in a communication state of the first port P1, the second port P2, the third port P3, and the fourth port P4, based on an instruction from the control unit 40. In the first state, the first port P1 and the second port P2 communicate with each other, and the third port P3 and the fourth port P4 communicate with each other. In the second state, the first port P1 and the fourth port P4 communicate with each other, and the second port P2 and the third port P3 communicate with each other.

[0030] The first port P1 is connected to the discharge portion 11b of the compressor 11. The second port P2 is connected to the second flow pipe 180a of the heat exchanger 100. The third port P3 is connected to the intake portion 11a of the compressor 11. The fourth port P4 is connected to one end of the heat source heat exchanger 13.

[0031] The heat source heat exchanger 13 causes heat exchange between the refrigerant circulating in the refrigerant circuit 10 and a heat source (for example, outdoor air).

[0032] The expansion valve 14 functions as a decompression device that adjusts the flow rate of the refrigerant circulating in the refrigerant circuit 10 and decompresses the refrigerant.

[0033] One end of the expansion valve 14 is connected to the other end of the heat source heat exchanger 13. The other end of the expansion valve 14 is connected to the second flow pipe 180b of the heat exchanger 100.(1-3) Water circuit 20

[0034] In the water circuit 20, the water after the heat exchange with the refrigerant circulates. The water circuit 20 includes the first flow path 111 of the heat exchanger 100, a water circulation pump 21, a flow rate adjustment valve 22, a first utilization heat exchanger 23, and a second utilization heat exchanger 24. The first flow path 111 of the heat exchanger 100, the water circulation pump 21, the flow rate adjustment valve 22, the first utilization heat exchanger 23, and the second utilization heat exchanger 24 are connected to each other by pipes, and water circulates therein.

[0035] The water circulation pump 21 makes the water circulate inside the water circuit 20. The water circulation pump 21 takes in water in the water circuit 20 through an intake portion 21a and discharges the water through a discharge portion 21b.

[0036] The intake portion 21a is connected to the first flow pipe 170a of the heat exchanger 100. The discharge portion 21b is connected to one end of the flow rate adjustment valve 22.

[0037] The flow rate adjustment valve 22 adjusts the flow rate of water circulating in the water circuit 20.

[0038] The first utilization heat exchanger 23 exchanges heat between the water circulating in the water circuit 20 and water stored in a water storage tank 31 (described below) of the water supply unit 30. The first utilization heat exchanger 23 is disposed inside the water storage tank 31 so that water passing therethrough can exchange heat with the water stored in the water storage tank 31.

[0039] One end of the first utilization heat exchanger 23 is connected to the other end of the flow rate adjustment valve 22. The other end of the first utilization heat exchanger 23 is connected to the first flow pipe 170b of the heat exchanger 100.

[0040] The second utilization heat exchanger 24 exchanges heat between the water circulating in the water circuit 20 and the air in an air conditioning target space (not illustrated). The second utilization heat exchanger 24 is arranged inside the air conditioning target space so that water passing through the second utilization heat exchanger 24 can exchange heat with the air in the air conditioning target space.

[0041] One end of the second utilization heat exchanger 24 is connected to the discharge portion 21b of the water circulation pump 21. The other end of the second utilization heat exchanger 24 is connected to the first flow pipe 170b of the heat exchanger 100.

[0042] The number of second utilization heat exchangers 24 included in the water circuit 20 may be one, or may be two or more as illustrated in Fig. 1.(1-4) Water supply unit 30

[0043] The water supply unit 30 causes heat exchange between the water supplied from the outside of the refrigeration apparatus 1 and the water circulating in the water circuit 20, and then supplies the water to the outside of the refrigeration apparatus 1. The water supply unit 30 includes the water storage tank 31, a water supply pump 32, and a mixing valve 33. The water storage tank 31, the water supply pump 32, and the mixing valve 33 are connected by a pipe.

[0044] The water storage tank 31 stores the water supplied from the outside. The stored water exchanges heat with the water passing through the first utilization heat exchanger 23. The water storage tank 31 takes in the water supplied from the outside through a water intake portion 31a and stores the water. The stored water exchanges heat with the water passing through the first utilization heat exchanger 23, and then is discharged through a water discharge portion 81b.

[0045] The water intake portion 31a is connected to the water intake unit 1a to which water is supplied from the outside.

[0046] The water supply pump 32 takes in water stored in the water storage tank 31 and supplies the water to the mixing valve 33. The water supply pump 32 takes in water inside the water storage tank 31 through an intake portion 32a, and discharges the water through a discharge portion 32b.

[0047] The intake portion 32a is connected to a water discharge portion 31b. The discharge portion 32b is connected to a second port 33b (described below) of the mixing valve 33.

[0048] The mixing valve 33 mixes water supplied from the outside and the water stored in the water storage tank 31. The mixing valve 33 has a first port 33a, the second port 33b, and a third port 33c.

[0049] The first port 33a is connected to the water intake unit 1a to which water is supplied from the outside. The second port 33b is connected to the discharge portion 32b of the water supply pump 32. The third port 33c is connected to the water supply unit 1b that communicates with the outside of the refrigeration apparatus 1.(1-5) Control unit 40

[0050] The control unit 40 controls the compressor 11, the four-way switching valve 12, the expansion valve 14, the water circulation pump 21, the flow rate adjustment valve 22, the water supply pump 32, and the mixing valve 33. Although not illustrated in the drawings, the control unit 40 is electrically connected to the compressor 11, the four-way switching valve 12, the expansion valve 14, the water circulation pump 21, the flow rate adjustment valve 22, the water supply pump 32, and the mixing valve 33 in such a manner that a control signal can be transmitted and received therebetween.(1-6) Operation of refrigeration apparatus 1

[0051] The refrigeration apparatus 1 performs a heating operation, a cooling operation, and a defrosting operation.(1-6-1) Heating operation

[0052] The heating operation is an operation in which the refrigeration apparatus 1 heats water that is supplied from the outside to the water intake unit 1a and supplies the heated water through the water supply unit 1b. In the heating operation, the control unit 40 sets the four-way switching valve 12 to the first state, drives the compressor 11, the water circulation pump 21, and the water supply pump 32, and controls the opening degrees of the expansion valve 14, the flow rate adjustment valve 22, and the mixing valve 33.(1-6-1-1) Refrigerant circuit 10

[0053] The compressor 11 takes in a low-pressure gas-phase refrigerant in the refrigerant circuit 10 through the intake portion 11a, and discharges the refrigerant as a high-pressure gas-phase refrigerant through the discharge portion 11b. The high-pressure gas-phase refrigerant passes through the four-way switching valve 12 in the order of the first port P1 and the second port P2, and reaches the second flow path 121 of the heat exchanger 100. In the second flow path 121 of the heat exchanger 100, the high-pressure gas-phase refrigerant is condensed into a high-pressure liquid-phase refrigerant. In this process, the refrigerant releases heat to the water passing through the first flow path 111. The high-pressure liquid-phase refrigerant reaches the expansion valve 14. The expansion valve 14 set to an appropriate opening degree decompresses the high-pressure liquid-phase refrigerant into a low-pressure gas-liquid two phase refrigerant. The low-pressure gas-liquid two phase refrigerant evaporates in the heat source heat exchanger 13 to become a low-pressure gas-phase refrigerant. In this process, the refrigerant absorbs heat from the heat source (outside air). The low-pressure gas-phase refrigerant passes through the four-way switching valve 12 in the order of the fourth port P4 and the third port P3, and is then taken into the compressor 11 through the intake portion 11a.(1-6-1-2) Water circuit 20

[0054] The water circulation pump 21 takes in water circulating in the water circuit 20 through the intake portion 21a and discharges the water through the discharge portion 21b. A part of the discharged water reaches the first utilization heat exchanger 23 through the flow rate adjustment valve 22. The water that has reached the first utilization heat exchanger 23 releases heat to the water stored in the water storage tank 31 in the first utilization heat exchanger 23. In other words, the water that has reached the first utilization heat exchanger 23 heats the water stored in the water storage tank 31. The remaining part of the water discharged from the water circulation pump 21 reaches the second utilization heat exchanger 24. The water that has reached the second utilization heat exchanger 24 releases heat to the air in the air conditioning target space. In other words, the water that has reached the second utilization heat exchanger 24 heats the air in the air conditioning target space. The water that has released heat in the first utilization heat exchanger 23 and the water that has released heat in the second utilization heat exchanger 24 reach the first flow path 111 of the heat exchanger 100. The water that has reached the first flow path 111 of the heat exchanger 100 absorbs heat from the refrigerant passing through the second flow path 121. The water that has absorbed heat is taken into the water circulation pump 21 through the intake portion 21a.(1-6-1-3) Water supply unit 30

[0055] The water stored in the water storage tank 31 is heated by absorbing heat from the water passing through the first utilization heat exchanger 23. The water supply pump 32 takes in the water heated in the water storage tank 31 through the intake portion 32a. The water taken into the water supply pump 32 is discharged through the discharge portion 32b to the mixing valve 33. The water discharged from the water supply pump 32 passes through the second port 33b and is then mixed with the water from the outside that has reached the first port 33a through the water intake unit 1a. The mixed water from the mixing valve 33 passes through the third port 33c and is then supplied to the outside of the refrigeration apparatus 1 from the water supply unit 1b.(1-6-2) Cooling operation

[0056] The cooling operation is an operation in which the refrigeration apparatus 1 cools water that is supplied from the outside to the water intake unit 1a and supplies the cooled water from the water supply unit 1b. In the cooling operation, the control unit 40 sets the four-way switching valve 12 to the second state, drives the compressor 11, the water circulation pump 21, and the water supply pump 32, and controls the opening degrees of the expansion valve 14, the flow rate adjustment valve 22, and the mixing valve 33.(1-6-2-1) Refrigerant circuit 10

[0057] The compressor 11 takes in a low-pressure gas-phase refrigerant in the refrigerant circuit 10 through the intake portion 11a, and discharges the refrigerant as a high-pressure gas-phase refrigerant through the discharge portion 11b. The high-pressure gas-phase refrigerant passes through the four-way switching valve 12 in the order of the first port P1 and the fourth port P4, and reaches the heat source heat exchanger 13. In the heat source heat exchanger 13, the high-pressure gas-phase refrigerant is condensed into a high-pressure liquid-phase refrigerant. In this process, the refrigerant releases heat to a heat source (outside air). The high-pressure liquid-phase refrigerant reaches the expansion valve 14. The expansion valve 14 set to an appropriate opening degree decompresses the high-pressure liquid-phase refrigerant into a low-pressure gas-liquid two phase refrigerant. The low-pressure gas-liquid two phase refrigerant evaporates in the second flow path 121 of the heat exchanger 100 to become a low-pressure gas-phase refrigerant. In this process, the refrigerant absorbs heat from the water passing through the first flow path 111. The low-pressure gas-phase refrigerant passes through the four-way switching valve 12 in the order of the second port P2 and the third port P3, and is then taken into the compressor 11 through the intake portion 11a.(1-6-2-2) Water circuit 20

[0058] The water circulation pump 21 takes in water circulating in the water circuit 20 through the intake portion 21a and discharges the water through the discharge portion 21b. A part of the discharged water reaches the first utilization heat exchanger 23 through the flow rate adjustment valve 22. The water that has reached the first utilization heat exchanger 23 absorbs heat from the water stored in the water storage tank 31 in the first utilization heat exchanger 23. In other words, the water that has reached the first utilization heat exchanger 23 cools the water stored in the water storage tank 31. The remaining part of the water discharged from the water circulation pump 21 reaches the second utilization heat exchanger 24. The water that has reached the second utilization heat exchanger 24 absorbs heat from the air in the air conditioning target space. In other words, the water that has reached the second utilization heat exchanger 24 cools the air in the air conditioning target space. The water that has absorbed heat in the first utilization heat exchanger 23 and the water that has absorbed heat in the second utilization heat exchanger 24 reach the first flow path 111 of the heat exchanger 100. The water that has reached the first flow path 111 of the heat exchanger 100 releases heat to the refrigerant passing through the second flow path 121. The water that has released heat is taken into the water circulation pump 21 through the intake portion 21a.(1-6-2-3) Water supply unit 30

[0059] The water stored in the water storage tank 31 is cooled by releasing heat to the water passing through the first utilization heat exchanger 23. The water supply pump 32 takes in water cooled in the water storage tank 31 through the intake portion 32a. The water taken into the water supply pump 32 is discharged through the discharge portion 32b to the mixing valve 33. The water discharged from the water supply pump 32 passes through the second port 33b and is then mixed with the water from the outside that has reached the first port 33a through the water intake unit 1a. The mixed water from the mixing valve 33 passes through the third port 33c and is then supplied to the outside of the refrigeration apparatus 1 from the water supply unit 1b.(1-6-3) Defrosting operation

[0060] The defrosting operation is an operation in which frost that has adhered to the surface of the heat source heat exchanger 13 during the heating operation is melted and removed by the heat of the refrigerant condensed in the heat source heat exchanger 13. The operation of each part of the refrigeration apparatus 1 in the defrosting operation is the same as that in the cooling operation described above. Therefore, a detailed description of the defrosting operation will be omitted.(2) Heat exchanger 100(2-1) Overall configuration

[0061] The heat exchanger 100 is a heat exchanger including a plurality of first inner fins 110, a plurality of second inner fins 120, a plurality of partition walls 130, a first separation member 140, a second separation member 150, a casing 160, the first flow pipe 170a, the first flow pipe 170b, the second flow pipe 180a, and the second flow pipe 180b. The first flow path 111 through which water flows and the second flow path 121 through which a refrigerant flows are formed inside the heat exchanger 100.

[0062] The first inner fins 110, the second inner fins 120, and the partition walls 130 are plate-shaped members made of metal and formed in the same rectangular outer shape. In the present embodiment, as illustrated in Fig. 2, the outer shapes of the first inner fins 110, the second inner fins 120, and the partition walls 130 are formed in a rectangular shape elongated in a first direction.

[0063] The first inner fins 110 and the second inner fins 120 are alternately stacked with the partition wall 130 interposed therebetween and are accommodated in the casing 160. The number of each of the first inner fins 110 and the second inner fins 120 is not limited, and is appropriately set according to the required performance.

[0064] In the following description, for the sake of simplicity, the first direction may be referred to as a longitudinal direction DL. A direction orthogonal to the first direction may be referred to as a width direction DW. Further, a direction in which the first inner fins 110, the partition walls 130, and the second inner fins 120 are stacked may be referred to as a stacking direction DS. The longitudinal direction DL, the width direction DW, and the stacking direction DS correspond to the directions indicated by the arrows in the drawings. The back, front, left, and right directions used in the following description correspond to the directions indicated by the arrows in the figures.(2-2) Detailed configuration(2-2-1) First inner fin 110

[0065] The first inner fin 110 is a corrugated fin having a corrugated cross section. The corrugated shape of the first inner fin 110 is formed such that a top portion 110t of the corrugated shape extends along the longitudinal direction DL in plan view. The first inner fin 110 forms the first flow path 111 together with the partition walls 130 adjacently stacked and the first separation member 140 separating the partition walls 130 from each other. The first inner fin 110 is formed by, for example, but not limited to, pressing.

[0066] Regarding the shape of the first inner fin 110, "corrugated" is not limited to a shape in which semicircular recesses and protrusions are periodically arranged as illustrated in Fig. 6, and may be a periodically changing shape such as a sine wave, a rectangular wave, or a triangular wave shape. The same applies to the second inner fin 120.(2-2-2) Second inner fin 120

[0067] The second inner fin 120 is a corrugated fin having a corrugated cross section. The corrugated shape of the second inner fin 120 is formed such that a top portion 120t of the corrugated shape extends along the longitudinal direction DL in plan view. The second inner fin 120 forms the second flow path 121 together with the partition walls 130 adjacently stacked. The second inner fin 120 is formed by, for example, but not limited to, pressing.(2-2-3) Partition wall 130

[0068] The partition wall 130 is a flat plate that separates the first inner fin 110 and the second inner fin 120 in the stacking direction DS. The partition wall 130 separates the first flow path 111 and the second flow path 121 in the stacking direction DS.(2-2-4) First separation member 140

[0069] The first separation member 140 is disposed at an end edge of the first flow path 111 and separates two adjacent ones of the partition walls 130 from each other in the stacking direction DS. In other words, the first separation member 140 is a member that separates two partition walls 130 from each other in order to dispose the first inner fin 110 between the partition walls 130 adjacent to each other in the stacking direction DS. The first separation member 140 is a strip-shaped member extending along the longitudinal direction DL. The first separation members 140 are disposed along both end edges of the partition wall 130 in the width direction DW. The height of the first separation member 140 in the stacking direction DS is set to be the same as the height of the first inner fin 110 in the stacking direction DS. The first inner fin 110 is disposed between the first separation members 140 disposed along both end edges of the partition wall 130 in the width direction DW.

[0070] The first separation member 140 is formed of a material different from a material of the second separation member 150 so that leakage of the refrigerant flowing through the second flow path 121 is suppressed when the water flowing through the first flow path 111 freezes and expands in volume. Specifically, the first separation member 140 is formed using a material having a Young's modulus smaller than the material of the second separation member 150. For example, the material of the first separation member 140 is copper or aluminum, whereas the material of the second separation member is SUS.(2-2-5) Second separation member 150

[0071] The second separation member 150 is disposed at an end edge of the second flow path 121 and separates two adjacent ones of the partition walls 130 from each other in the stacking direction DS. In other words, the second separation member 150 is a member that separates two partition walls 130 from each other in order to dispose the second inner fin 120 between the partition walls 130 adjacent to each other in the stacking direction DS. The second separation member 150 is a strip-shaped member extending along the longitudinal direction DL. The second separation members 150 are disposed along both end edges of the partition wall 130 in the width direction DW. The height of the second separation member 150 in the stacking direction DS is set to be the same as the height of the second inner fin 120 in the stacking direction DS. The first inner fin 110 is disposed between the second separation members 150 disposed along both end edges of the partition wall 130 in the width direction DW.(2-2-6) Casing 160

[0072] The casing 160 is a substantially rectangular parallelepiped member that accommodates the first inner fins 110, the second inner fins 120, the partition walls 130, the first separation members 140, and the second separation members 150. The casing 160 has two main surfaces 160a orthogonal to the stacking direction DS, two first side surfaces 160b, and two second side surfaces 160c. The main surfaces 140a are surfaces orthogonal to the stacking direction DS. The first side surfaces 160b are surfaces orthogonal to the longitudinal direction DL. The second side surfaces 160c are surfaces orthogonal to the width direction DW. A first header 141, a second header 142, a third header 143, and a fourth header 144 are formed inside the casing 160.

[0073] The first header 141 is a space in which water flowing into the casing 160 is distributed to the plurality of first flow paths 111, or the flows of water that have passed through the first flow paths 111 merge. The first header 141 is formed along the first side surface 160b on the front side.

[0074] The second header 142 is a space in which water flowing into the casing 160 is distributed to the plurality of first flow paths 111, or the flows of water that have passed through the first flow paths 111 merge. The second header 142 is formed along the first side surface 160b on the back side.

[0075] The third header 143 is a space in which the refrigerant flowing into the casing 160 is distributed to the plurality of second flow paths 121, or the flows of the refrigerant that have passed through the second flow paths 121 merge. The third header 143 is formed along the first side surface 160b on the front side.

[0076] The fourth header 144 is a space in which the refrigerant flowing into the casing 160 is distributed to the plurality of second flow paths 121, or the flows of the refrigerant that have passed through the second flow paths 121 merge. The fourth header 144 is formed along the first side surface 160b on the back side.(2-2-7) First flow pipe 170a and first flow pipe 170b

[0077] The first flow pipe 170a is a pipe for making water flow through the first flow paths 111. The first flow pipe 170a is provided, in the casing 160, through the first side surface 160b on the front side and communicates with the first header 141.

[0078] The first flow pipe 170b is a pipe for making water flow through the first flow paths 111. The first flow pipe 170b is provided, in the casing 160, through the first side surface 160b on the back side and communicates with the second header 142.(2-2-8) Second flow pipe 180a and second flow pipe 180b

[0079] The second flow pipe 180a is a pipe for making the refrigerant flow through the second flow paths 121. The second flow pipe 180a is provided, in the casing 160, through the second side surface 160c on the right side and communicates with the third header 143.

[0080] The second flow pipe 180b is a pipe for making the refrigerant flow through the second flow paths 121. The second flow pipe 180b is provided, in the casing 160, through the second side surface 160c on the right side and communicates with the fourth header 144.(2-2-9) First flow path 111 and second flow path 121

[0081] The first inner fin 110 is accommodated in a space surrounded by two partition walls 130 adjacent to each other in the stacking direction DS and two first separation members 140 disposed between these partition walls 130, whereby the plurality of first flow paths 111 arranged in the width direction DW are formed. The first flow path 111 is a space surrounded by the first inner fin 110 and the partition wall 130 and extending in the longitudinal direction DL, and a space surrounded by the first inner fin 110, the partition wall 130, and the first separation member 140 and extending in the longitudinal direction DL.

[0082] The first inner fin 110, the partition wall 130, and the first separation member 140 are joined by diffusion joining. More specifically, the first inner fin 110 has the top portion 110t of the corrugated shape joined to the partition wall 130 by diffusion joining. A surface of the first separation member 140 orthogonal to the stacking direction DS is joined to the partition wall 130 by diffusion joining. Hereinafter, a portion where the partition wall 130 and the first separation member 140 are joined is referred to as a first joining portion 140c.

[0083] The second inner fin 120 is accommodated in a space surrounded by two partition walls 130 adjacent to each other in the stacking direction DS and two second separation members 150 disposed between these partition walls 130, whereby the plurality of second flow paths 121 arranged in the width direction DW are formed. The second flow path 121 is a space surrounded by the second inner fin 120 and the partition wall 130 and extending in the longitudinal direction DL, and a space surrounded by the second inner fin 120, the partition wall 130, and the second separation member 150 and extending in the longitudinal direction DL.

[0084] The second inner fin 120, the partition wall 130, and the second separation member 150 are joined by diffusion joining. More specifically, the second inner fin 120 has the top portion 120t of the corrugated shape joined to the partition wall 130 by diffusion joining. A surface of the second separation member 150 orthogonal to the stacking direction DS is joined to the partition wall 130 by diffusion joining. Hereinafter, a portion where the partition wall 130 and the second separation member 150 are joined is referred to as a second joining portion 150c.(2-3) Flow of refrigerant and water

[0085] The water introduced from the first flow pipe 170a of the heat exchanger 100 passes through the first header 141 and flows into the first flow path 111. The water that has flowed into the first flow path 111 flows through the first flow path 111 toward the back side along the longitudinal direction DL. The water that has reached the back side passes through the second header 142 and is led out from the first flow pipe 170b. In addition, the water introduced from the first flow pipe 170b of the heat exchanger 100 passes through the second header 142 and flows into the first flow path 111. The water that has flowed into the first flow path 111 flows through the first flow path 111 toward the front side along the longitudinal direction DL. The water that has reached the front side passes through the first header 141 and is led out from the first flow pipe 170a. In either case, the water flowing through the first flow path 111 exchanges heat with the refrigerant in the adjacent second flow path 121 via the partition wall 130.

[0086] On the other hand, the refrigerant introduced from the second flow pipe 180a of the heat exchanger 100 passes through the third header 143 and flows into the second flow path 121. The refrigerant that has flowed into the second flow path 121 flows through the second flow path 121 toward the back side along the longitudinal direction DL. The refrigerant that has reached the back side passes through the fourth header 144 and is led out from the second flow pipe 180b. The refrigerant introduced from the second flow pipe 180b of the heat exchanger 100 passes through the fourth header 144 and flows into the second flow path 121. The refrigerant that has flowed into the second flow path 121 flows through the second flow path 121 toward the front side along the longitudinal direction DL. The refrigerant that has reached the front side passes through the third header 143 and is led out from the second flow pipe 180a. In either case, the water flowing through the second flow path 121 is condensed (during the heating operation) or evaporated (during the cooling operation and the defrosting operation) by exchanging heat with the water in the adjacent first flow path 111 via the partition wall 130.(3) Features

[0087] (3-1) The heat exchanger 100 is a heat exchanger that causes heat exchange between water and a refrigerant, and includes the first flow path 111 through which the water flows, the second flow path 121 through which the refrigerant flows, the partition walls 130, the first separation member 140, and the second separation member 150. The partition wall 130 separates the first flow path 111 and the second flow path 121. The first separation member 140 is disposed at an end edge of the first flow path 111 and separates two adjacent ones of the partition walls 130 from each other. The second separation member 150 is disposed at an end edge of the second flow path 121 and separates two adjacent ones of the partition walls 130 from each other. The first separation member 140 is made of a material different from a material of the second separation member 150 and / or has a shape different from a shape of the second separation member 150.

[0088] Generally, when a refrigerant and water are used as fluids in a refrigeration apparatus using a plate-type heat exchanger, a separation member may rupture when the water freezes and expands in volume, to cause leakage of the refrigerant, or a partition wall separating a flow path of the refrigerant and a flow path of the water may rupture to cause the refrigerant flowing into the flow path of the water through the rupturing part to flow into an air conditioning target space.

[0089] In the heat exchanger 100, when the water flowing through the first flow path 111 freezes and expands in volume, the first separation member 140 ruptures before the second separation member 150 ruptures. Therefore, according to the heat exchanger 100, rupturing of the second separation member 150 due to freezing of the water flowing through the first flow path 111 is suppressed, and thus leakage of the refrigerant flowing through the second flow path 121 to the outside of the heat exchanger 100 is suppressed.

[0090] (3-2) The material of the first separation member 140 has a smaller Young's modulus than the material of the second separation member 150.

[0091] The first separation member 140 made of a material with a Young's modulus smaller than a material of the second separation member 150 ruptures before the second separation member 150 ruptures when the water flowing through the first flow path 111 freezes and expands in volume. Therefore, according to the heat exchanger 100, rupturing of the second separation member 150 due to freezing of the water flowing through the first flow path 111 is suppressed, and thus leakage of the refrigerant flowing through the second flow path 121 to the outside of the heat exchanger 100 is suppressed.

[0092] (3-3) The material of the first separation member 140 is copper or aluminum. The material of the second separation member 150 is SUS.

[0093] (3-4) The first separation member 140 and the second separation member 150 are joined to the partition wall 130 using diffusion joining.

[0094] (3-5) The refrigeration apparatus 1 includes the heat exchanger 100.(4) Modifications(4-1) Modification A

[0095] The first separation member 140 may be formed to have a shape different from that of the second separation member 150 so that leakage of the refrigerant flowing through the second flow path 121 is suppressed when the water flowing through the first flow path 111 freezes and expands in volume. Specifically, the first separation member 140 may have a recessed portion 140d, recessed toward the first flow path 111, formed on the outer surface thereof. Fig. 7 is a cross-sectional view of a heat exchanger 100 according to Modification A.

[0096] When the water flowing through the first flow path 111 freezes and expands in volume, the first separation member 140 having the recessed portion 140d ruptures before the second separation member 150 ruptures, due to stress concentrated on the recessed portion 140d. Therefore, according to the heat exchanger 100 according to Modification A, rupturing of the second separation member 150 due to freezing of the water flowing through the first flow path 111 is suppressed, and thus leakage of the refrigerant flowing through the second flow path 121 to the outside of the heat exchanger 100 is suppressed.

[0097] In the heat exchanger 100 according to Modification A, the first separation member 140 may be formed using a material different from that of the second separation member 150 as in the above-described embodiment, or may be formed using the same material as that of the second separation member 150.(4-2) Modification B

[0098] The shape of the first separation member 140 is not limited to the aspect of Modification A as long as leakage of the refrigerant flowing through the second flow path 121 is suppressed when the water flowing through the first flow path 111 freezes and expands in volume. Specifically, the first separation member 140 may be formed with a width d1 of the first joining portion 140c in the width direction DW being smaller than a width d2 of the second joining portion 150c in the width direction DW. Fig. 8 is a cross-sectional view of a heat exchanger 100 according to Modification B.

[0099] Since the width d1 is smaller than the width d2, when the same pressure is generated in the first flow path 111 and the second flow path 121, the first joining portion 140c receives a larger stress than that on the second joining portion 150c. Therefore, when the water flowing through the first flow path 111 freezes and expands in volume, the first joining portion 140c ruptures before the second joining portion 150c ruptures. Therefore, according to the heat exchanger 100 according to Modification B, rupturing of the second separation member 150 due to freezing of the water flowing through the first flow path 111 is suppressed, and thus leakage of the refrigerant flowing through the second flow path 121 to the outside of the heat exchanger 100 is suppressed.

[0100] As illustrated in Fig. 8, the joining portion (second joining portion 150c) of the second separation member 150 with the partition wall 130 may have a portion overlapping the first flow path 111 as viewed in the stacking direction DS (region 150d indicated by a dotted line in Fig. 8). In this case, as viewed in the stacking direction DS, the width d1 of the first separation member 140 may be not more than 1 / 2 of the width d2 of the second separation member 150. In the second separation member 150, a width d2a (the same as d2-d1 in the present embodiment), in the width direction DW, of the region 150d overlapping the first flow path 111 may be equal to or more than a width d2b (the same as d1 in the present embodiment) of the portion not overlapping the first flow path 111 in the stacking direction DS.

[0101] In the heat exchanger 100 according to Modification B, the first separation member 140 may be formed using a material different from that of the second separation member 150 as in the above-described embodiment, or may be formed using the same material as that of the second separation member 150.(4-3) Modification C

[0102] In the above-described embodiment, the refrigerant used is propane, but the refrigerant used is not limited thereto, and a well-known refrigerant such as HC, HFC (R410A, R32, or the like), HFO, or a natural refrigerant can be used.

[0103] According to the heat exchanger 100, even when a flammable or toxic refrigerant is used, the leakage of the refrigerant due to the rupturing of the members or the joining portions forming the second flow path 121 can be suppressed. The flammable refrigerant refers to a refrigerant classified as 2L or higher in the standard of ANSI / ASHRAE34 in the United States.(4-4) Modification D

[0104] In the above-described embodiment, the first inner fins 110 and the second inner fins 120 are stacked such that both the first flow paths 111 and the second flow paths 121 are arranged in the width direction DW, but the arrangement of the first inner fins 110 and the second inner fins 120 is not limited thereto. For example, the first inner fins 110 and the second inner fins 120 may be stacked such that one of the first flow paths 111 and the second flow paths 121 are arranged in the width direction DW and the other of the first flow paths 111 and the second flow paths 121 are arranged in the longitudinal direction DL.

[0105] While embodiments of the present disclosure have been described above, it should be understood that various changes in mode and detail may be made without departing from the spirit and scope of the present disclosure as set forth in the claims.Reference Signs List

[0106] 1 Refrigeration apparatus 100 Heat exchanger 111 First flow path 121 Second flow path 130 Partition wall 140 First separation member 140d Recessed portion 150 Second separation member DS Stacking direction Citation ListPatent Literature

[0107] PTL 1: Japanese Unexamined Patent Application Publication No. 10-132476

Claims

1. A heat exchanger (100) that causes heat exchange between water and a refrigerant, the heat exchanger comprising: a first flow path (111) through which the water flows; a second flow path (121) through which the refrigerant flows; partition walls (130) configured to separate the first flow path (111) and the second flow path (121) from each other; a first separation member (140) disposed at an end edge of the first flow path (111) and configured to separate two adjacent ones of the partition walls (130) from each other; and a second separation member (150) disposed at an end edge of the second flow path (121) and configured to separate two adjacent ones of the partition walls (130) from each other, wherein the first separation member (140) is made of a material different from a material of the second separation member (150) and / or has a shape different from a shape of the second separation member (150).

2. The heat exchanger (100) according to claim 1, wherein the material of the first separation member (140) has a smaller Young's modulus than the material of the second separation member (150).

3. The heat exchanger (100) according to claim 2, wherein the material of the first separation member (140) is copper or aluminum, and the material of the second separation member (150) is SUS.

4. The heat exchanger (100) according to claim 1, wherein the first separation member (140) has a recessed portion (140d), recessed toward the first flow path (111), formed on an outer surface.

5. The heat exchanger (100) according to claim 1, wherein a width (d1) of the first separation member (140) is smaller than a width (d2) of the second separation member (150).

6. The heat exchanger (100) according to claim 5, wherein a joining portion (150c) of the second separation member (150) with the partition wall (130) includes a portion (150d) overlapping the first flow path (111) as viewed in a stacking direction (DS).

7. The heat exchanger (100) according to claim 6, wherein the width (d1) of the first separation member (140) is not more than 1 / 2 of the width (d2) of the second separation member (150).

8. The heat exchanger (100) according to claim 1, wherein the first separation member (140) and the second separation member (150) are joined to the partition walls (130) using diffusion joining.

9. The heat exchanger (100) according to any one of claims 1 to 8, wherein the refrigerant is flammable or toxic.

10. A refrigeration apparatus (1) comprising the heat exchanger (100) according to any one of claims 1 to 9.

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