Heat exchangers, refrigeration units

Abstract

A heat exchanger capable of suppressing bias in the flow rate of a refrigerant flowing into a flow path that functions as a heat transfer area. [Solution] A first header of a heat exchanger has a plurality of first protrusions formed thereon. The first header is formed so as to connect the first communication passage with the recess and not connect the second communication passage with the recess. In the first header, the density of the first protrusions formed in the first region is lower than the density of the first protrusions formed in the second region. The first region is a region between two first straight lines in a plan view of the first plate. The first straight lines extend in the second direction, passing through both ends of the second through hole in a third direction perpendicular to the second direction in which the first through hole and the second through hole are aligned. The second region is a region excluding the first region.

Description

[Technical Field]

[0001] This invention relates to a heat exchanger and a refrigeration device. [Background technology]

[0002] Patent Document 1 (JP 2024-012151 A) discloses a plate heat exchanger. The plates of the plate heat exchanger of Patent Document 1 are formed with a heat transfer area, two flow ports, two through holes, and two headers. A first fluid, which is one of the heat transfer media, flows in from one of the flow ports and flows through the heat transfer area via the header. A second fluid, which is the other heat transfer media, passes through the through holes. The header is formed to surround the flow port and the through holes, and connects the flow port and the heat transfer area. The header has protrusions formed on its surface to ensure pressure resistance. The through holes are formed between the heat transfer area and the flow port. Summary of the Invention [Problem to be solved by the invention]

[0003] In the plate heat exchanger disclosed in Patent Document 1, the through holes obstruct part of the flow of the first fluid flowing from the flow port toward the heat transfer region. As a result, the amount of the first fluid in the heat transfer region downstream of the through holes is smaller than the flow rate in other regions. As a result, the flow rate is unbalanced in the flow paths that function as the heat transfer region, which can hinder the heat exchange efficiency.

[0004] An object of the present disclosure is to provide a heat exchanger that can suppress bias in the flow rate of a refrigerant flowing into a flow path that functions as a heat transfer area. [Means for solving the problem]

[0005] A heat exchanger according to a first aspect is a plate heat exchanger in which a plurality of plates are stacked in a first direction, and includes a first communication passage, a second communication passage, a first flow path, and a second flow path.

[0006] The first communication passage allows a first fluid to flow in a first direction. The second communication passage allows a second fluid to flow in the first direction. The first flow path allows the first fluid flowing through the first communication passage to flow along the surface of a first plate included in the plurality of plates. The second flow path allows the second fluid flowing through the second communication passage to flow along the surface of a second plate included in the plurality of plates.

[0007] The first plate has a recess, two first through holes, and two second through holes, and the second plate has a recess, two first through holes, and two second through holes.

[0008] The recessed portion forms a first flow path or a second flow path when blocked by other plates included in the adjacent stacked plates. The first through-hole constitutes a part of the first communication path and is formed so as to sandwich the recessed portion in a plan view of the multiple plates. The second through-hole constitutes a part of the second communication path and is formed between the first through-hole and the recessed portion in a plan view of the multiple plates.

[0009] The first plate has a first header formed to surround the first through hole and the second through hole in a plan view of the first plate.

[0010] The first header has a plurality of first protrusions formed thereon. The first header is formed so as to communicate the first communication passage with the recess and not communicate the second communication passage with the recess. The density of the first protrusions formed in the first region of the first header is lower than the density of the first protrusions formed in the second region. The first region is a region between two first straight lines in a plan view of the first plate. The first straight lines extend in the second direction, passing through both ends of the second through hole in a third direction perpendicular to the second direction in which the first through hole and the second through hole are aligned. The second region is a region excluding the first region.

[0011] The flow of the first fluid that flows out of the first through-hole and into the first header is controlled by the first protrusions before it enters the first flow path. Specifically, because the density of the first protrusions formed in the first region of the first header is lower than the density of the first protrusions formed in the second region, the first protrusions inhibit the smooth flow of the first fluid. As a result, more of the first fluid flows into the first region located on the recessed side of the second through-hole than into the second region. This allows the heat exchanger to suppress bias in the flow rate of the first fluid flowing into the first flow path, which functions as a heat transfer region.

[0012] A heat exchanger of a second aspect is a heat exchanger of the first aspect, wherein the average size of the first protrusions formed in the first region when viewed in plan of the first plate may be different from the average size of the first protrusions formed in the second region when viewed in plan of the first plate.

[0013] A heat exchanger of a third aspect is the heat exchanger of the first aspect, wherein the number of first protrusions formed in the first region per unit area may be different from the number of first protrusions formed in the second region per unit area.

[0014] A heat exchanger of a fourth aspect is any one of the heat exchangers of the first aspect to the third aspect, and in a plan view of the first plate, the density of the first protrusions formed in a first region between a second straight line passing through the center of the second through hole and extending in a third direction and an edge of the recess facing the second through hole may be smaller than the density of the first protrusions formed in a second region between the second straight line and the edge of the recess facing the second through hole.

[0015] This feature promotes the inflow of the first fluid from the second region to the first region, thereby making it possible for the heat exchanger to further suppress bias in the flow rate of the first fluid flowing into the first flow path that functions as the heat transfer region.

[0016] A heat exchanger of a fifth aspect is the heat exchanger of the fourth aspect, wherein, in a planar view of the first plate, the density of the first protrusions formed in a first region between a third straight line passing through the center of the first through hole and extending in a third direction and an edge of the recess facing the second through hole may be smaller than the density of the first protrusions formed in a second region between the third straight line and the edge of the recess facing the second through hole.

[0017] This feature promotes the inflow of the first fluid from the second region to the first region, thereby making it possible for the heat exchanger to further suppress bias in the flow rate of the first fluid flowing into the first flow path that functions as the heat transfer region.

[0018] A heat exchanger of a sixth aspect is a heat exchanger of the fifth aspect, wherein, in a planar view of the first plate, the density of the first protrusions formed in the second region between the third straight line and the edge of the first header facing the first through hole may be smaller than the density of the first protrusions formed in the second region between the third straight line and the edge of the recess facing the second through hole.

[0019] A heat exchanger according to a seventh aspect is any of the heat exchangers according to the first aspect to the sixth aspect, wherein the first plate may further include a second header formed to sandwich the recess together with the first header and to surround the first through-hole and the second through-hole in a plan view of the first plate. A plurality of second protrusions may be formed on the second header. The second header may be formed so as to communicate the first communication passage with the recess and not to communicate the second communication passage with the recess. The second header may have the second protrusions formed at a constant density in a plan view of the first plate.

[0020] A heat exchanger according to an eighth aspect is any of the heat exchangers according to the first aspect to the sixth aspect, wherein the first plate may further include a second header formed to sandwich the recess together with the first header and to surround the first through hole and the second through hole in a plan view of the first plate. A plurality of second protrusions may be formed on the second header. The second header may be formed to communicate the first communication passage with the recess and not to communicate the second communication passage with the recess. In a plan view of the first heat transfer plate, the density of the second protrusions formed in the first region may be lower than the density of the second protrusions formed in the second region.

[0021] A heat exchanger according to a ninth aspect is the heat exchanger according to the eighth aspect, wherein the second projections may be arranged symmetrically with respect to the first projections with respect to the recessed portion.

[0022] A heat exchanger according to a tenth aspect is any one of the heat exchangers according to the first aspect to the ninth aspect, wherein the second plate may have a third header formed to surround the second through hole in a plan view of the second plate. A plurality of third protrusions may be formed on the third header. The third header may be formed so as to communicate between the second communication passage and the recess and not to communicate between the first communication passage and the recess. In the third header, the density of the third protrusions formed in the third region may be greater than the density of the third protrusions formed in the fourth region. The third region is a region between two fourth straight lines in a plan view of the second plate. The fourth straight lines extend in the fourth direction, passing through both ends of the second through hole in a fifth direction perpendicular to the fourth direction in which the first through hole and the second through hole are aligned. The fourth region is a region excluding the third region.

[0023] The flow of the second fluid that flows out of the first through-holes and into the third header is controlled by the third protrusions before it enters the second flow path. Specifically, in the third header, the density of the third protrusions formed in the third region is greater than the density of the third protrusions formed in the fourth region, so the third protrusions inhibit the smooth flow of the second fluid. As a result, more of the second fluid flows into the fourth region, which is the region excluding the recessed side of the first through-holes, than into the third region. This allows the heat exchanger to suppress bias in the flow rate of the second fluid flowing into the second flow path, which functions as a heat transfer region.

[0024] A heat exchanger according to an eleventh aspect is the heat exchanger according to the tenth aspect, wherein the second plate may further include a fourth header formed to sandwich the recess together with the third header and to surround the second through hole in a plan view of the second plate. The fourth header may have a plurality of fourth protrusions formed thereon. The fourth header may be formed so as to communicate the second communication passage with the recess and not to communicate the first communication passage with the recess. The fourth header may have the fourth protrusions formed at a constant density in a plan view of the second plate.

[0025] A heat exchanger according to a twelfth aspect is the heat exchanger according to the tenth aspect, wherein the second plate may further include a fourth header formed to sandwich the recess together with the third header and to surround the second through hole in a plan view of the second plate. The fourth header may have a plurality of fourth protrusions formed thereon. The fourth header may be formed to communicate between the second communication passage and the recess and not to communicate between the first communication passage and the recess. In the fourth header, the density of the third protrusions formed in the third region 3 may be greater than the density of the fourth protrusions formed in the fourth region in a plan view of the second plate.

[0026] A heat exchanger according to a thirteenth aspect is the heat exchanger according to any one of the first aspect to the twelfth aspect, wherein the inner diameter of the first communication passage is larger than the inner diameter of the second communication passage.

[0027] A heat exchanger according to a fourteenth aspect is the heat exchanger according to any one of the first aspect to the twelfth aspect, wherein the inner diameter of the first communication passage is smaller than the inner diameter of the second communication passage.

[0028] A heat exchanger of a fifteenth aspect is any one of the heat exchangers of the first aspect to the fourteenth aspect, and the direction in which the first fluid flows through the first flow path may be opposite to the direction in which the second fluid flows through the second flow path when viewed in a plan view of the multiple plates.

[0029] A heat exchanger according to a sixteenth aspect is the heat exchanger according to any one of the first aspect to the fifteenth aspect, wherein either the first flow path or the second flow path may be formed by an inner fin and a recess.

[0030] A refrigeration device according to a seventeenth aspect includes the heat exchanger according to any one of the first to sixteenth aspects.

[0031] The heat exchanger suppresses unevenness in the flow rate of the fluid and efficiently exchanges heat, so that the refrigeration system can achieve highly efficient operation. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a schematic diagram of a refrigeration device 1. FIG. [Figure 2] FIG. 2 is an exploded view of the first heat exchanger 100. [Figure 3] FIG. 2 is an enlarged cross-sectional view of the first heat exchanger 100. [Figure 4] FIG. 10 is a plan view of the first heat transfer plate 110 showing the arrangement of the protrusions 115. [Figure 5] FIG. 10 is a plan view of the first heat transfer plate 110 showing the arrangement of the protrusions 115. [Figure 6] FIG. 10 is a plan view of the first heat transfer plate 110 showing the arrangement of the protrusions 115. [Figure 7] 10 is a plan view of the second heat transfer plate 130 showing the arrangement of the protrusions 135. FIG. [Figure 8] 10 is a plan view of the second heat transfer plate 130 showing the arrangement of the protrusions 135. FIG. [Figure 9] FIG. 10 is a plan view illustrating the flow rate of a refrigerant in a heat transfer plate according to the prior art. [Figure 10]10 is a plan view illustrating the flow rate of the first refrigerant flowing into the first flow path in the first heat transfer plate 110. FIG. [Figure 11] 10 is a plan view for explaining the flow rate of the second refrigerant flowing into the second flow path in the second heat transfer plate 130. FIG. [Figure 12] 10 is a plan view of a first heat transfer plate 110 showing the arrangement of protrusions 115 in a first heat exchanger 100 according to a first modified example. FIG. [Figure 13] 10 is a plan view of a second heat transfer plate 130 showing the arrangement of protrusions 135 in a first heat exchanger 100 according to a first modified example. FIG. [Figure 14] 10 is a cross-sectional view showing the structure of a first flow path 210 and a second flow path 220 in a first heat exchanger 100 according to a fifth modified example. FIG. [Figure 15] 10 is a cross-sectional view showing the structure of a first flow path 210 and a second flow path 220 in a first heat exchanger 100 according to a sixth modification. FIG. [Figure 16] 10 is a cross-sectional view showing the structure of a first flow path 210 and a second flow path 220 in a first heat exchanger 100 according to a seventh modification. FIG. [Figure 17] 13 is a cross-sectional view showing the structure of a first flow path 210 and a second flow path 220 in a first heat exchanger 100 according to another example of the seventh modified example. FIG. [Figure 18] 10 is a plan view of the first heat transfer plate 110 showing another example of the protrusions 115. FIG. [Figure 19] 10 is a plan view of the first heat transfer plate 110 showing another example of the protrusions 115. FIG. [Figure 20] 10 is a plan view of the first heat transfer plate 110 showing another example of the protrusions 115. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0033] First Embodiment (1) Overall configuration of refrigeration device 1 First, a refrigeration system 1 including a first heat exchanger 100 according to a first embodiment of the present disclosure will be described. Fig. 1 is a schematic diagram of the refrigeration system 1. The refrigeration system 1 is a binary refrigerant cycle system that performs heating and cooling operations in a space to be air-conditioned (not shown), such as the interior of a building, by executing a vapor compression cycle.

[0034] The refrigeration system 1 heats or cools water and uses the water to perform heating and cooling operations in a space to be air-conditioned (not shown). The refrigeration system 1 has a first heat exchanger 100, a second heat exchanger 300, a first refrigerant circuit 10, a second refrigerant circuit 20, a water circuit 30, and a control unit 40. As will be described in detail later, the refrigeration system 1 is configured so that a first refrigerant circulates in the first refrigerant circuit 10, a second refrigerant circulates in the second refrigerant circuit 20, and water circulates in the water circuit 30. Although not limited thereto, in this embodiment, the water circuit 30 is installed indoors and the second refrigerant circuit 20 is installed outdoors. The first refrigerant circuit 10 may be installed either indoors or outdoors, or a portion of it may be installed either indoors or outdoors.

[0035] The first refrigerant is an example of a first fluid, and the second refrigerant is an example of a second fluid.

[0036] (1-1) 1st heat exchanger 100 The first heat exchanger 100 exchanges heat between a first refrigerant circulating through the first refrigerant circuit 10 and a second refrigerant circulating through the second refrigerant circuit 20. The first heat exchanger 100 has first flow ports 141a and 141b, second flow ports 142a and 142b, a first flow path 210, and a second flow path 220.

[0037] First flow path 210 is a flow path through which a first refrigerant flows. First flow path 210 functions as a heat transfer area where heat exchange occurs between the first refrigerant flowing therethrough and the second refrigerant flowing through second flow path 220. First flow path 210 is provided between first flow port 141a and first flow port 141b.

[0038] The second flow path 220 is a flow path through which the second refrigerant flows. The second flow path 220 functions as a heat transfer area where heat exchange occurs between the second refrigerant flowing therethrough and the first refrigerant flowing through the first flow path 210. The second flow path 220 is formed between the second flow port 142a and the second flow port 142b. The first refrigerant flowing through the first flow path 210 exchanges heat with the second refrigerant passing through the second flow path 220. The detailed structure of the first heat exchanger 100 will be described later.

[0039] (1-2)Second heat exchanger 300 The second heat exchanger 300 exchanges heat between the second refrigerant circulating through the second refrigerant circuit 20 and the water circulating through the water circuit 30. The second heat exchanger 300 has first flow ports 341a and 341b, second flow ports 342a and 342b, a first flow path 410, and a second flow path 420.

[0040] First flow path 410 is a flow path through which the second refrigerant flows. First flow path 410 is provided between first flow port 341a and first flow port 341b. Second flow path 420 is a flow path through which water flows. Second flow path 420 is formed between second flow port 342a and second flow port 342b. The second refrigerant flowing through first flow path 410 exchanges heat with the water passing through second flow path 420.

[0041] (1-3) 1st refrigerant circuit 10 In the first refrigerant circuit 10, a first refrigerant is heated or cooled. The first refrigerant circuit 10 is composed of a compressor 11, a four-way switching valve 12, an expansion valve 13, a first flow path 210 of the first heat exchanger 100, and a heat-source heat exchanger 14. The compressor 11, the four-way switching valve 12, the expansion valve 13, the first flow path 210 of the first heat exchanger 100, and the heat-source heat exchanger 14 are connected by piping, and the first refrigerant circulates inside. In this embodiment, the first refrigerant is carbon dioxide.

[0042] The compressor 11 draws in the low-pressure first refrigerant in the first refrigerant circuit 10 through a suction port 11a, compresses it, and discharges it from a discharge port 11b as a high-pressure first refrigerant.

[0043] The four-way switching valve 12 has a first port 12a, a second port 12b, a third port 12c, and a fourth port 12d. Based on instructions from the control unit 40, the four-way switching valve 12 switches between a first state and a second state, in which the communication states of the first port 12a, the second port 12b, the third port 12c, and the fourth port 12d are different. In the first state, the first port 12a and the second port 12b are communicated with each other, and the third port 12c and the fourth port 12d are communicated with each other. In the second state, the first port 12a and the fourth port 12d are communicated with each other, and the second port 12b and the third port 12c are communicated with each other.

[0044] The first port 12a is connected to the discharge portion 11b of the compressor 11. The second port 12b is connected to the first flow port 141a of the first heat exchanger 100. The third port 12c is connected to the suction portion 11a of the compressor 11. The fourth port 12d is connected to one end of the heat source heat exchanger 14.

[0045] The expansion valve 13 adjusts the flow rate of the first refrigerant circulating through the first refrigerant circuit 10, and functions as a pressure reducing device that reduces the pressure of the first refrigerant.

[0046] One end of the expansion valve 13 is connected to the first flow port 141b of the first heat exchanger 100. The other end of the expansion valve 13 is connected to the other end of the heat source heat exchanger .

[0047] The heat source heat exchanger 14 exchanges heat between the first refrigerant circulating in the first refrigerant circuit 10 and a heat source (for example, outdoor air).

[0048] (1-4)Second refrigerant circuit 20 In the second refrigerant circuit 20, a second refrigerant is heated or cooled. The second refrigerant circuit 20 is composed of a compressor 21, a four-way switching valve 22, an expansion valve 23, a second flow path 220 of the first heat exchanger 100, and a first flow path 410 of the second heat exchanger 300. The compressor 21, the four-way switching valve 22, the expansion valve 23, the second flow path 220 of the first heat exchanger 100, and the first flow path 410 of the second heat exchanger 300 are connected by piping, and the second refrigerant circulates inside. In this embodiment, the second refrigerant is propane.

[0049] The compressor 21 draws in the low-pressure second refrigerant in the second refrigerant circuit 20 through the suction port 21a, compresses it, and discharges it from the discharge port 21b as the high-pressure second refrigerant.

[0050] The four-way switching valve 22 has a first port 22a, a second port 22b, a third port 22c, and a fourth port 22d. Based on instructions from the control unit 40, the four-way switching valve 22 switches between a first state and a second state, in which the communication states of the first port 22a, the second port 22b, the third port 22c, and the fourth port 22d are different. In the first state, the first port 22a and the second port 22b are communicated with each other, and the third port 22c and the fourth port 22d are communicated with each other. In the second state, the first port 22a and the fourth port 22d are communicated with each other, and the second port 22b and the third port 22c are communicated with each other.

[0051] The first port 22a is connected to the discharge portion 21b of the compressor 21. The second port 22b is connected to the first flow port 341a of the second heat exchanger 300. The third port 22c is connected to the suction portion 21a of the compressor 21. The fourth port 22d is connected to the second flow port 142a of the first heat exchanger 100.

[0052] The expansion valve 23 adjusts the flow rate of the second refrigerant circulating through the second refrigerant circuit 20, and functions as a pressure reducing device that reduces the pressure of the second refrigerant.

[0053] One end of the expansion valve 23 is connected to the first flow port 341b of the second heat exchanger 200. The other end of the expansion valve 23 is connected to the second flow port 142b of the first heat exchanger 100.

[0054] (1-5) Water circuit 30 Water that has exchanged heat with the second refrigerant circulates in the water circuit 30. The water circuit 30 is composed of a water circulation pump 31, a water storage tank 32, a second flow path 420 of the second heat exchanger 300, and a utilization heat exchanger 33. The water circulation pump 31, the water storage tank 32, the second flow path 420 of the second heat exchanger 300, and the utilization heat exchanger 33 are connected by piping, and water circulates inside.

[0055] The water circulation pump 31 circulates water inside the water circuit 30. The water circulation pump 31 draws water from the inside of the water circuit 30 through an intake port 31a and discharges the water from an outlet port 31b.

[0056] The intake section 31 a is connected to the second flow port 342 b of the second heat exchanger 300 .

[0057] The water storage tank 32 stores water heated or cooled by the second heat exchanger 300 to heat or cool (in other words, provide heating or cooling) the air in the space to be air-conditioned. The water storage tank 32 has a water intake section 32a that takes in water circulating through the water circuit 30, and a drainage section 32b that discharges the stored water.

[0058] The water intake portion 32a is connected to the discharge portion 31b of the water circulation pump 31. The water discharge portion 32b is connected to the second flow port 342a of the second heat exchanger 300.

[0059] The utilization heat exchanger 33 exchanges heat between the water circulating through the water circuit 30 and the air in the space to be air-conditioned (not shown). The utilization heat exchanger 33 is disposed inside the space to be air-conditioned so that the water passing through it can exchange heat with the air in the space to be air-conditioned. One end of the utilization heat exchanger 33 is connected to the discharge portion 31b of the water circulation pump 31. The other end of the utilization heat exchanger 33 is connected to the second flow port 342a of the second heat exchanger 300. The number of utilization heat exchangers 33 included in the water circuit 30 may be one, or, as shown in FIG. 1, may be two or more.

[0060] (1-6) Control unit 40 The control unit 40 controls the compressors 11, 21, the four-way switching valves 12, 22, the expansion valves 13, 23, and the water circulation pump 31. Although not shown in the figure, the control unit 40 is electrically connected to the compressors 11, 21, the four-way switching valves 12, 22, the expansion valves 13, 23, and the water circulation pump 31 so as to be able to send and receive control signals.

[0061] (1-7) Operation of Refrigeration Device 1 The refrigeration device 1 performs heating operation and cooling operation.

[0062] (1-7-1) Heating operation The heating operation is an operation in which the refrigeration device 1 heats the water in the water circuit 30. In the heating operation, the control unit 40 sets the four-way switching valves 12, 22 to the first state, drives the compressors 11, 21 and the water circulation pump 31, and controls the opening degrees of the expansion valves 13, 23.

[0063] (1-7-1-1) 1st refrigerant circuit 10 Compressor 11 draws low-pressure gas-phase first refrigerant from first refrigerant circuit 10 through suction port 11a and discharges it as high-pressure gas-phase first refrigerant from discharge port 11b. The high-pressure gas-phase first refrigerant passes through four-way selector valve 12, first port 12a and then second port 12b, and reaches first flow path 210 from first outlet 141a of first heat exchanger 100. In first flow path 210 of first heat exchanger 100, the high-pressure gas-phase first refrigerant condenses into high-pressure liquid-phase first refrigerant. At this time, the first refrigerant releases heat to the second refrigerant passing through second flow path 220. The high-pressure liquid-phase first refrigerant flowing out of first heat exchanger 100 reaches expansion valve 13. Expansion valve 13, set to an appropriate opening, reduces the pressure of the high-pressure liquid-phase first refrigerant to a low-pressure gas-liquid two-phase first refrigerant. The low-pressure gas-liquid two-phase first refrigerant evaporates in heat source heat exchanger 14 and becomes a low-pressure gas-phase first refrigerant. At this time, the first refrigerant absorbs heat from the heat source. The low-pressure gas-phase first refrigerant that flows out of heat source heat exchanger 14 passes through four-way selector valve 12, in this order, via fourth port 12d and third port 12c, and is then drawn into compressor 11 from suction port 11a.

[0064] (1-7-1-2) Second refrigerant circuit 20 Compressor 21 draws low-pressure gas-phase second refrigerant from second refrigerant circuit 20 through suction port 21a and discharges it as high-pressure gas-phase second refrigerant from discharge port 21b. The high-pressure gas-phase second refrigerant passes through four-way selector valve 22, first through first port 22a and then second port 22b, and reaches first flow path 410 from first outlet 341a of second heat exchanger 300. In first flow path 410 of second heat exchanger 300, the high-pressure gas-phase second refrigerant condenses into high-pressure liquid-phase second refrigerant. At this time, the second refrigerant releases heat to water passing through second flow path 420. The high-pressure liquid-phase second refrigerant flowing out of second heat exchanger 300 reaches expansion valve 23. Expansion valve 23, set to an appropriate opening, reduces the pressure of the high-pressure liquid-phase second refrigerant to form a low-pressure gas-liquid two-phase second refrigerant. The low-pressure gas-liquid two-phase second refrigerant passes through second flow port 142b of first heat exchanger 100, and then evaporates in second flow path 220 to become low-pressure gas-phase second refrigerant. At this time, the second refrigerant absorbs heat from the first refrigerant passing through first flow path 210. The low-pressure gas-phase second refrigerant that has flowed out of first heat exchanger 100 passes through fourth port 22d and third port 22c of four-way selector valve 22 in this order, and is then drawn into compressor 21 from suction port 21a.

[0065] (1-7-1-3) Water circuit 30 The water circulation pump 31 draws water circulating through the water circuit 30 through the intake section 31a and discharges it through the discharge section 31b. A portion of the discharged water passes through the water intake section 32a and is stored in the water storage tank 32, while the remainder passes through the utilization heat exchanger 33. Both the water stored in the water storage tank 32 and the water passing through the utilization heat exchanger 33 release heat to the air in the air-conditioned space. In other words, the water stored in the water storage tank 32 and the water passing through the utilization heat exchanger 33 heat the air in the air-conditioned space. After passing through the discharge section 32b, the water stored in the water storage tank 32 passes through the second flow port 342a of the second heat exchanger 300 and reaches the second flow path 420. The water that has passed through the utilization heat exchanger 33 passes through the second flow port 342a of the second heat exchanger 300 and reaches the second flow path 420. The water that reaches second flow path 420 of second heat exchanger 300 absorbs heat from the second refrigerant passing through first flow path 410. The water that has absorbed the heat is drawn into water circulation pump 31 from suction portion 31a.

[0066] (1-7-2) Cooling operation The cooling operation is an operation in which the refrigeration device 1 cools the water in the water circuit 30. In the cooling operation, the control unit 40 sets the four-way switching valves 12, 22 to the second state, drives the compressors 11, 21 and the water circulation pump 31, and controls the opening degrees of the expansion valves 13, 23.

[0067] (1-7-2-1) 1st refrigerant circuit 10 The compressor 11 draws the low-pressure gas-phase first refrigerant from the first refrigerant circuit 10 through the suction port 11a and discharges it as a high-pressure gas-phase first refrigerant from the discharge port 11b. The high-pressure gas-phase first refrigerant passes through the four-way switching valve 12, first through the first port 12a and then through the fourth port 12d, and reaches the heat-source heat exchanger 14. In the heat-source heat exchanger 14, the high-pressure gas-phase first refrigerant condenses into a high-pressure liquid-phase first refrigerant. At this time, the first refrigerant releases heat to the heat source. The high-pressure liquid-phase first refrigerant flowing out of the heat-source heat exchanger 14 reaches the expansion valve 13. The expansion valve 13, with its opening set appropriately, reduces the pressure of the high-pressure liquid-phase first refrigerant to a low-pressure two-phase gas-liquid first refrigerant. The low-pressure two-phase gas-liquid first refrigerant passes through the first flow port 141b of the first heat exchanger 100 and evaporates in the first flow path 210 to become a low-pressure gas-phase first refrigerant. At this time, the first refrigerant absorbs heat from the second refrigerant passing through second flow path 220. The low-pressure gas-phase first refrigerant flowing out of first heat exchanger 100 passes through four-way selector valve 12, in this order, via second port 12b and third port 12c, and is then drawn into compressor 21 via suction port 11a.

[0068] (1-7-2-2) Second refrigerant circuit 20 Compressor 21 draws low-pressure gas-phase second refrigerant from second refrigerant circuit 20 through suction port 21a and discharges it as high-pressure gas-phase second refrigerant from discharge port 21b. The high-pressure gas-phase second refrigerant passes through four-way selector valve 22, first through second port 22b and then through fourth port 22d, and reaches second flow path 220 through second outlet 142a of first heat exchanger 100. In second flow path 220 of first heat exchanger 100, the high-pressure gas-phase second refrigerant condenses into high-pressure liquid-phase second refrigerant. At this time, the second refrigerant releases heat to the first refrigerant passing through first flow path 210. The high-pressure liquid-phase second refrigerant flowing out of first heat exchanger 100 reaches expansion valve 23. Expansion valve 23, with an appropriate opening, reduces the pressure of the high-pressure liquid-phase second refrigerant to produce a low-pressure gas-liquid two-phase second refrigerant. The low-pressure gas-liquid two-phase second refrigerant passes through first flow port 341b of second heat exchanger 300, and then evaporates in first flow path 410 to become low-pressure gas-phase second refrigerant. At this time, the second refrigerant absorbs heat from water passing through second flow path 420. The low-pressure gas-phase second refrigerant that has flowed out of second heat exchanger 300 passes through second port 22b and third port 22c of four-way switching valve 22 in this order, and is then drawn into compressor 21 from suction port 21a.

[0069] (1-7-2-3) Water circuit 30 The water circulation pump 31 draws water circulating through the water circuit 30 through the intake section 31a and discharges it from the discharge section 31b. A portion of the discharged water passes through the water intake section 32a and is stored in the water storage tank 32, while the remainder passes through the utilization heat exchanger 33. Both the water stored in the water storage tank 32 and the water passing through the utilization heat exchanger 33 absorb heat from the air in the air-conditioned space. In other words, the water stored in the water storage tank 32 and the water passing through the utilization heat exchanger 33 cool the air in the air-conditioned space. After passing through the discharge section 32b, the water stored in the water storage tank 32 passes through the second flow port 342a of the second heat exchanger 300 and reaches the second flow path 420. The water that has passed through the utilization heat exchanger 33 passes through the second flow port 342a of the second heat exchanger 300 and reaches the second flow path 420. The water that reaches second flow path 420 of second heat exchanger 300 releases heat to the second refrigerant passing through first flow path 410. The water that has released the heat is drawn into water circulation pump 31 from suction port 31a.

[0070] (2) 1st heat exchanger 100 (2-1) Overall structure The first heat exchanger 100 is a plate-type heat exchanger composed of a plurality of plates. Fig. 2 is an exploded view of the first heat exchanger 100. Fig. 3 is an enlarged cross-sectional view of the first heat exchanger 100. Specifically, Fig. 3 is an enlarged cross-sectional view of the periphery of upper inner holes 112, 122, and 132 and outer holes 111, 121, and 131 (all of which will be described later). In Fig. 3, the flow directions of the first refrigerant and the second refrigerant during cooling operation are indicated by arrows.

[0071] The first heat exchanger 100 includes, as plates, a plurality of first heat transfer plates 110, a plurality of partition walls 120, a plurality of second heat transfer plates 130, a first end frame 140, and a second end frame 150. The first heat exchanger 100 has a first flow path 210 and a second flow path 220 therein.

[0072] The first heat transfer plate 110, the partition wall 120, and the second heat transfer plate 130 have the same size and outer peripheral shape. In this embodiment, as shown in Fig. 2, the first heat transfer plate 110, the partition wall 120, the second heat transfer plate 130, the first end frame 140, and the second end frame 150 have a strip-like outer shape.

[0073] The plurality of first heat transfer plates 110 and the plurality of second heat transfer plates 130 are stacked alternately between the first end frame 140 and the second end frame 150, with partition walls 120 sandwiched between them. The number of the plurality of first heat transfer plates 110 and the number of the plurality of second heat transfer plates 130 is not particularly limited and is set appropriately depending on the required performance. The first end frame 140, the first heat transfer plates 110, the partition walls 120, the second heat transfer plates 130, and the second end frame 150 are integrally joined by, but not limited to, diffusion bonding, for example.

[0074] In the following description, for convenience, the longitudinal direction of the first heat transfer plate 110, the partition wall 120, and the second heat transfer plate 130 may be referred to as the longitudinal direction DL. Furthermore, the width direction of the first heat transfer plate 110, the partition wall 120, and the second heat transfer plate 130 may be referred to as the width direction DW. Furthermore, the thickness direction (in other words, the stacking direction) of the first heat transfer plate 110, the partition wall 120, and the second heat transfer plate 130 may be referred to as the thickness direction DT (see the arrows shown in some of the drawings for both directions). Furthermore, the up and down directions referred to in the following description correspond to the "up" and "down" shown in some of the drawings.

[0075] The first heat exchanger 100 is an example of a plate heat exchanger. The first heat transfer plate 110, the partition wall 120, and the second heat transfer plate 130 are an example of a plurality of plates. The first heat transfer plate 110 is an example of a first plate. The second heat transfer plate 130 is an example of a second plate. The thickness direction DT is an example of a first direction. The longitudinal direction DL is an example of a second direction and a fourth direction. The width direction DW is an example of a third direction and a fifth direction.

[0076] (2-2) Detailed configuration (2-2-1) First heat transfer plate 110 The first heat transfer plate 110, together with the adjacently stacked partition walls 120, forms a first flow path 210. The first heat transfer plate 110 has two outer holes 111, two inner holes 112, two headers 113, and a recess 114 formed therein.

[0077] The outer holes 111 are through-holes through which the first refrigerant flows. The outer holes 111 penetrate the first heat transfer plate 110 along the thickness direction DT. The outer holes 111 constitute part of first communication passages 161 (described later) and are formed above and below the recesses 114 in a plan view of the first heat transfer plate 110. The outer holes 111 are circular in a plan view of the first heat transfer plate 110. The outer holes 111 are formed between an upper edge 110eu of the first heat transfer plate 110 and the header 113, and between a lower edge 110eb of the first heat transfer plate 110 and the header 113 in a plan view of the first heat transfer plate 110.

[0078] The inner hole 112 is a through-hole through which the second refrigerant flows. The inner hole 112 penetrates the first heat transfer plate 110 along the thickness direction DT. The inner hole 112 constitutes part of a second communication passage 162 (described later), and is formed above and below the recess 114 in a plan view of the first heat transfer plate 110. The inner hole 112 has a circular shape in a plan view of the first heat transfer plate 110. In this embodiment, the inner diameter of the inner hole 112 is larger than the inner diameter of the outer hole 111.

[0079] The inner hole 112 includes a seal portion 112s. The seal portion 112s prevents the second refrigerant flowing through the inner hole 112 from flowing into the header 113. The seal portion 112s is a protrusion formed to surround the inner hole 112 in a plan view of the first heat transfer plate 110. The seal portion 112s protrudes from the surface of the header 113 to the same height as wall portions 114b (described below) that separate adjacent grooves 114a.

[0080] The header 113 communicates between the inner hole 112 and the recess 114, and diverts a portion of the first refrigerant flowing through a first communication passage 161 (described later) to the recess 114. The two headers 113 are formed in positions sandwiching the recess 114 from above and below in a plan view of the first heat transfer plate 110, so as to surround the outer hole 111 and the inner hole 112, respectively. The surface of the header 113 is flush with the bottom surface of a groove 114a (described later) formed in the recess 114.

[0081] One of the two headers 113 (hereinafter referred to as the first header 113a) is a rectangular area surrounded by the upper edge 110eu of the first heat transfer plate 110, both end edges 110es in the width direction DW, and the upper ends of the recesses 114 in a plan view of the first heat transfer plate 110. The other of the two headers 113 (hereinafter referred to as the second header 113b) is a rectangular area surrounded by the lower edge 110eb of the first heat transfer plate 110, parts of both end edges 110es in the width direction DW, and the lower ends of the recesses 114 in a plan view of the first heat transfer plate 110. The two headers 113 have the same shape and size. A plurality of protrusions 115 are formed on the surface of the header 113 (see FIG. 3). The protrusions 115 will be described in detail later.

[0082] The recess 114 is a region through which the first refrigerant flows after being diverted by the header 113. The recess 114 is formed in a rectangular shape in a plan view of the first heat transfer plate 110, at the center in the longitudinal direction DL of the first heat transfer plate 110. The recess 114 forms a first flow path 210 by being closed by another plate (in this embodiment, the partition wall 120) included in the plurality of adjacently stacked plates.

[0083] In this embodiment, a plurality of linear grooves 114a are formed in the recess 114 along the longitudinal direction DL. The grooves 114a are formed at predetermined intervals along the width direction DW. Adjacent grooves 114a are separated by wall portions 114b. One end of each groove 114a contacts the first header 113a, and the other end contacts the second header 113b.

[0084] Without limitation, the header 113, the seal portion 112s, the recess 114, the groove 114a, and the protrusion 115 are formed using etching.

[0085] The outer hole 111 is an example of a first through hole, and the inner hole 112 is an example of a second through hole.

[0086] (2-2-2) Bulkhead 120 The partition wall 120 separates the first heat transfer plate 110 and the second heat transfer plate 130 in the thickness direction DT.

[0087] The partition wall 120 is a flat plate in which two outer holes 121 and two inner holes 122 are formed.

[0088] The outer holes 121 are through-holes through which the first refrigerant flows. The outer holes 121 penetrate the partition wall 120 along the thickness direction DT. The outer holes 121 have the same shape and size as the outer holes 111 of the first heat transfer plate 110. Furthermore, the outer holes 121 are formed at positions that overlap with the outer holes 111 of the heat transfer plate 110a when the partition wall 120 is stacked on the first heat transfer plate 110.

[0089] The inner holes 122 are through-holes through which the second refrigerant flows. The inner holes 122 penetrate the partition wall 120 along the thickness direction DT. The inner holes 122 have the same shape and size as the inner holes 112 of the heat transfer plate 110a. Furthermore, the inner holes 122 are formed at positions that overlap with the inner holes 112 of the heat transfer plate 110a when the partition wall 120 is stacked on the first heat transfer plate 110.

[0090] (2-2-3) Second heat transfer plate 130 The second heat transfer plate 130 is adjacent to the partition wall 120 on the surface opposite to the first heat transfer plate 110. The second heat transfer plate 130 forms a second flow path 220 together with the adjacent partition wall 120 stacked thereon. The second heat transfer plate 130 has two outer holes 131, two inner holes 132, two headers 133, and a recess 134 formed therein.

[0091] The outer holes 131 are through-holes through which the first refrigerant flows. The outer holes 131 penetrate the second heat transfer plate 130 along the thickness direction DT. The outer holes 131 constitute part of first communication passages 161 (described later) and are formed above and below the recesses 134 in a plan view of the second heat transfer plate 130. The outer holes 131 have the same shape and size as the outer holes 111 of the first heat transfer plate 110 and the outer holes 121 of the partition walls 120. Furthermore, the outer holes 131 are formed at positions that overlap with the outer holes 121 of the partition walls 120 when the partition walls 120 are stacked on the second heat transfer plate 130.

[0092] The inner holes 132 are through-holes through which the second refrigerant flows. The inner holes 132 penetrate the second heat transfer plate 130 along the thickness direction DT. The inner holes 132 constitute part of second communication passages 162 (described later) and are formed above and below the recesses 134 in a plan view of the second heat transfer plate 130. The inner holes 132 have the same shape and size as the inner holes 112 of the first heat transfer plate 110 and the inner holes 122 of the partition walls 120. The inner holes 132 are formed at positions that overlap with the inner holes 122 of the partition walls 120 when the partition walls 120 are stacked on the second heat transfer plate 130. In this embodiment, the inner diameter of the inner holes 132 is larger than the inner diameter of the outer holes 131.

[0093] The header 133 communicates between the outer hole 131 and the recess 134, and diverts a portion of the second refrigerant flowing through a second communication passage 162 (described later) to the recess 134. The two headers 133 are formed at positions sandwiching the recess 134 from above and below in a plan view of the second heat transfer plate 130, so that each header does not surround the outer hole 131 but surrounds the inner hole 132. The surface of the header 133 is flush with the bottom surface of a groove 114a (described later) formed in the recess 134.

[0094] One of the two headers 133 (hereinafter referred to as the fourth header 133b) is a rectangular region surrounded by a boundary 130b extending in the width direction DW between the upper outer hole 131 and the inner hole 132, both end edges 130es in the width direction DW, and the upper end of the recess 114 in a plan view of the second heat transfer plate 130. The other of the two headers 133 (hereinafter referred to as the third header 133a) is a rectangular region surrounded by a boundary 130b extending in the width direction DW between the lower outer hole 131 and the inner hole 132, both end edges 130es in the width direction DW, and the lower end of the recess 134 in a plan view of the second heat transfer plate 130. The two headers 133 have the same shape and size. The header 133 has a plurality of protrusions 135 provided on its surface (see FIG. 3). The protrusions 135 will be described in detail later.

[0095] The recess 134 is a region through which the second refrigerant diverted by the header 133 flows. The recess 134 is formed in the center of the second heat transfer plate 130 in the longitudinal direction DL, and has a rectangular shape when viewed from above the second heat transfer plate 130. The recess 134 is closed by another plate (in this embodiment, the partition wall 120) included in the plurality of adjacently stacked plates, thereby forming a second flow path 220.

[0096] In this embodiment, a plurality of linear grooves 134a are formed in the recess 134 along the longitudinal direction DL. The grooves 134a are formed at predetermined intervals along the width direction DW. Adjacent grooves 134a are separated by wall portions 134b. One end of the grooves 134a contacts the first header 113a, and the other end contacts the fourth header 133b.

[0097] Without limitation, the header 133, recess 134, groove 134a, and protrusion 135 are formed using etching.

[0098] The outer hole 131 is an example of a first through hole, and the inner hole 132 is an example of a second through hole.

[0099] (2-2-4) First End Frame 140 and Second End Frame 150 The first end frame 140 is a plate-like member having first flow ports 141a and 141b and second flow ports 142a and 142b.

[0100] The first flow ports 141a and 141b are through holes formed in the first end frame 140. The first refrigerant flows into the first heat exchanger 100 through either the first flow port 141a or the first flow port 141b. The first flow port 141a is disposed at a position communicating with the outer holes 111, 121, and 131 formed above. The first flow port 141b is disposed at a position communicating with the outer holes 111, 121, and 131 formed below.

[0101] The second flow ports 142a and 142b are through holes formed in the first end frame 140. The second refrigerant flows into the first heat exchanger 100 through the second flow ports 142a and 142b. The second flow port 142a is disposed at a position communicating with the inner holes 112, 122, and 132 formed above. The second flow port 142b is disposed at a position communicating with the inner holes 112, 122, and 132 formed below.

[0102] (2-2-5) Assembly of the first heat exchanger 100 The first flow paths 210 are formed by stacking the partition walls 120 on the first heat transfer plate 110 and closing the openings of the grooves 114a with the surfaces of the partition walls 120. As a result, the first flow paths 210 cause the first refrigerant that has flowed through the first communication passages 161 (described below) to flow along the surface of the first heat transfer plate 110.

[0103] The second flow paths 220 are formed by stacking the partition walls 120 on the second heat transfer plate 130 and closing the openings of the grooves 134a with the surfaces of the partition walls 120. As a result, the second flow paths 220 cause the second refrigerant that has flowed through the second communication passages 162 (described below) to flow along the surface of the second heat transfer plate 130.

[0104] By stacking the first heat transfer plate 110, the partition wall 120, and the second heat transfer plate 130, the outer holes 111, 121, and 131 communicate with each other to form a first communication passage 161 through which the first refrigerant flowing in from the first flow ports 141a and 141b flows along the thickness direction DT. Furthermore, by stacking the first heat transfer plate 110, the partition wall 120, and the second heat transfer plate, the inner holes 112, 122, and 132 communicate with each other to form a second communication passage 162 through which the second refrigerant flowing in from the second flow ports 142a and 142b flows along the thickness direction DT. In this embodiment, the inner diameter of the first communication passage 161 is larger than the inner diameter of the second communication passage 162.

[0105] By stacking the first end frame 140 on the stacked first heat transfer plate 110, partition wall 120, and second heat transfer plate 130, the first circulation port 141 communicates with the first communication passage 161, and the second circulation port 142 communicates with the second communication passage 162.

[0106] The partition wall 120 is stacked on the first heat transfer plate 110, and the surface of the partition wall 120 comes into contact with the surface of the seal portion 133s, so that the seal portion 133s prevents the second refrigerant flowing through the inner hole 132 from flowing into the header 113 (see Figure 3).

[0107] (2-3) Flow of the first and second refrigerants (2-3-1) Flow of the first refrigerant In heating operation, the first refrigerant that flows into first flow port 141a of first heat exchanger 100 flows through upper first communication passage 161. A portion of the first refrigerant flowing through first communication passage 161 passes through first header 113a and flows into first flow passage 210 (groove 114a of recess 114). The first refrigerant that flows into first flow passage 210 flows along the longitudinal direction DL, and then passes through second header 113b and flows into lower first communication passage 161. In other words, first flow passage 210 causes the first refrigerant flowing through first communication passage 161 to flow along the surface of first heat transfer plate 110. The first refrigerant that flows into lower first communication passage 161 flows out of first heat exchanger 100 through first flow port 141b.

[0108] In cooling operation, the first refrigerant flows in the opposite direction to that in heating operation. Specifically, the first refrigerant that flows into first circulation port 141b of first heat exchanger 100 flows through lower first communication passage 161. A portion of the first refrigerant flowing through first communication passage 161 passes through second header 113b and flows into first flow path 210 (groove 114a of recess 114). The first refrigerant that flows into first flow path 210 flows along the longitudinal direction DL, and then passes through first header 113a and flows into upper first communication passage 161. The first refrigerant that flows into upper first communication passage 161 flows out of first heat exchanger 100 through first circulation port 141a (see arrow A in FIG. 3).

[0109] (2-3-2) Flow of the second refrigerant In heating operation, the second refrigerant that flows into the second flow port 142b of the first heat exchanger 100 flows through the lower second communication passage 162. A portion of the second refrigerant flowing through the second communication passage 162 passes through the second header 113b and flows into the second flow passage 220 (the groove 134a of the recess 134). The second refrigerant that flows into the second flow passage 220 flows along the longitudinal direction DL, and then passes through the first header 113a and flows into the upper second communication passage 162. In other words, the second flow passage 220 causes the second refrigerant flowing through the second communication passage 162 to flow along the surface of the second heat transfer plate 130. The second refrigerant that flows into the upper second communication passage 162 flows out of the first heat exchanger 100 through the second flow port 142a.

[0110] In cooling operation, the second refrigerant flows in the opposite direction to that in cooling operation. Specifically, the second refrigerant that flows into second flow port 142a of first heat exchanger 100 flows through upper second communication passage 162 (see arrow B in FIG. 3). A portion of the second refrigerant flowing through second communication passage 162 passes through first header 113a and flows into second flow passage 220 (groove 134a of recess 134). The second refrigerant that flows into second flow passage 220 flows along the longitudinal direction DL and then passes through second header 113b and flows into lower second communication passage 162. The second refrigerant that flows into lower second communication passage 162 flows out of first heat exchanger 100 through second flow port 142b (see arrow B in FIG. 3).

[0111] As described above, the direction in which the first refrigerant flows through the first flow path 210 is opposite to the direction in which the second fluid flows through the second flow path 220 when viewed in a plan view of the first heat transfer plate 110, the partition wall 120, and the second heat transfer plate 130.

[0112] (2-4) Protrusions 115 and 135 The protrusions 115 prevent the first refrigerant flowing through the header 113 into the first flow passage 210 from becoming uneven in flow rate. The protrusions 135 prevent the second refrigerant flowing through the header 133 into the second flow passage 220 from becoming uneven in flow rate. Figures 4, 5, and 6 are plan views of the first heat transfer plate 110 showing the arrangement of the protrusions 115. Figures 7 and 8 are plan views of the second heat transfer plate 130 showing the arrangement of the protrusions 135. Figures 5, 6, and 8 are enlarged views of the upper headers 113, 133. For convenience, the protrusions 115, 135 are omitted from Figures 5, 6, and 8.

[0113] (2-4-1) Protrusion 115 The first heat transfer plate 110 is formed such that, in a plan view of the first heat transfer plate 110, the density of the protrusions 115 formed in the first region a1 of the header 113 is different from the density of the protrusions 115 formed in the second region a2 of the header 113. Specifically, the first heat transfer plate 110 is formed such that, in a plan view of the first heat transfer plate 110, the density of the protrusions 115 formed in the first region a1 is smaller than the density of the protrusions 115 formed in the second region a2.

[0114] The first region a1 is the region between two first straight lines L1. The first straight lines L1 extend in the longitudinal direction DL, passing through both ends of the inner hole 112 in the width direction DW, which is perpendicular to the longitudinal direction DL in which the outer hole 111 and the inner hole 112 are aligned. The second region a2 is the region of the header 113 excluding the first region a1 (see FIG. 5). "Both ends of the inner hole 112" refer to both ends of the seal portion 112s.

[0115] In a plan view of the first heat transfer plate 110, the density of the first protrusions 115a formed in the first region a1 between the second straight line L2 passing through the center of the inner hole 112 and extending in the width direction DW and the edge 114e of the recess 114 facing the inner hole 112 is lower than the density of the first protrusions 115a formed in the first portion a21 of the second region a2. The first portion a21 of the second region a2 is a region of the second region a2 between the second straight line L2 passing through the center of the inner hole 112 and extending in the width direction DW and the edge 114e of the recess 114 facing the inner hole 112 in the longitudinal direction DL in a plan view of the first heat transfer plate 110 (see FIG. 6 ).

[0116] In a plan view of the first heat transfer plate 110, the density of the first protrusions 115a formed in the first region a1 between a third straight line L3 that passes through the center of the outer hole 111 and extends in the width direction DW and the edge 114e of the recess 114 that faces the inner hole 112 is lower than the density of the first protrusions 115a formed in the first portion a21 and the second portion a22 of the second region a2. The second portion a22 of the second region a2 is a region of the second region a2 between the third straight line L3 and the second straight line L2 in a plan view of the first heat transfer plate 110 (see FIG. 6).

[0117] In a plan view of the first heat transfer plate 110, the density of the first protrusions 115a formed in the third portion a23 of the second region a2 may be lower than the density of the first protrusions 115a formed in the first portion a21 and the second portion a22 of the second region a2. The third portion a23 of the second region a2 is a region of the second region a2 between the third straight line L3 and the edge 113e of the header 113 that faces the outer hole 111 in the longitudinal direction DL in a plan view of the first heat transfer plate 110 (see FIG. 6).

[0118] In this embodiment, the difference in density of the protrusions 115 is achieved by the difference in the number of protrusions 115 per unit area. Specifically, in this embodiment, the protrusions 115 of the first heat transfer plate 110 have the same size and shape in a plan view, and the number of protrusions 115 formed in the first region a1 per unit area is smaller than the number of protrusions 115 formed in the second region a2 per unit area.

[0119] In this embodiment, as shown in FIG. 4, the protrusion 115 (hereinafter referred to as the first protrusion 115a) formed on the second header 113b is positioned symmetrically with the protrusion 115 (hereinafter referred to as the second protrusion 115b) formed on the first header 113a across the recess 114.

[0120] (2-4-2) Protrusion 135 The second heat transfer plate 130 is formed such that, in a plan view of the second heat transfer plate 130, the density of the protrusions 135 formed in the third region a3 of the header 133 differs from the density of the protrusions 135 formed in the fourth region a4 of the header 133. Specifically, the second heat transfer plate 130 is formed such that, in a plan view of the second heat transfer plate 130, the density of the protrusions 135 formed in the third region a3 is greater than the density of the protrusions 135 formed in the fourth region a4.

[0121] The third region a3 is a region between two fourth straight lines L4. The fourth straight lines L4 extend in the longitudinal direction DL, passing through both ends of the inner hole 132 in the width direction DW, which is perpendicular to the longitudinal direction DL in which the outer hole 131 and the inner hole 132 are aligned. The fourth region a4 is a region of the header 133 excluding the third region a3 (see FIG. 8).

[0122] In this embodiment, the difference in density of the protrusions 135 is achieved by the difference in the number of protrusions 135 per unit area. Specifically, in this embodiment, the protrusions 135 of the second heat transfer plate 130 have the same size and shape in a plan view, and the number of the protrusions 135 formed in the third region a3 per unit area is smaller than the number of the protrusions 135 formed in the fourth region a4 per unit area.

[0123] In this embodiment, as shown in FIG. 5, the protrusion 135 formed on the third header 133a (hereinafter referred to as the third protrusion 135a) is positioned symmetrically with the protrusion 135 formed on the fourth header 133b (hereinafter referred to as the fourth protrusion 135b) across the recess 134.

[0124] (3) Features (3-1) The first heat exchanger 100 is a plate heat exchanger in which a plurality of plates are stacked in a thickness direction DT. The first heat exchanger 100 includes a first communication passage 161, a second communication passage 162, a first flow path 210, and a second flow path 220.

[0125] The first communication passage 161 allows the first fluid to flow along the thickness direction DT. The second communication passage 162 allows the second fluid to flow along the thickness direction DT. The first flow path 210 allows the first fluid flowing through the first communication passage 161 to flow along the surface of the first heat transfer plate 110 included in the plurality of plates. The second flow path 220 allows the second fluid flowing through the second communication passage 162 to flow along the surface of the second heat transfer plate 130 included in the plurality of plates.

[0126] The first heat transfer plate 110 has a recess 114, two outer holes 111, and two inner holes 112. The second heat transfer plate 130 has a recess 134, two outer holes 131, and two inner holes 132.

[0127] The recess 114 is blocked by another plate included in the adjacent stacked plates to form a first flow path 210. The recess 134 is blocked by another plate included in the adjacent stacked plates to form a second flow path 220. The outer hole 111 constitutes a part of the first communication path 161 and is formed so as to sandwich the recess 114 in a plan view of the multiple plates. The outer hole 131 constitutes a part of the first communication path 161 and is formed so as to sandwich the recess 134 in a plan view of the multiple plates. The inner hole 112 constitutes a part of the second communication path 162 and is formed between the outer hole 111 and the recess 114 in a plan view of the multiple plates. The inner hole 132 constitutes a part of the second communication path 162 and is formed between the outer hole 131 and the recess 134 in a plan view of the multiple plates.

[0128] The first heat transfer plate 110 has a first header 113a formed so as to surround the outer hole 111 and the inner hole 112 when the first heat transfer plate 110 is seen in a plan view.

[0129] The first header 113a has a plurality of first protrusions 115a formed thereon. The first header 113a is formed so as to connect the first communication passage 161 and the recess 114, but not so as to connect the second communication passage 162 and the recess 114. In the first header 113a, the density of the first protrusions 115a formed in the first region a1 is lower than the density of the first protrusions 115a formed in the second region a2. The first region a1 is a region between two first straight lines L1 in a plan view of the first heat transfer plate 110. The first straight line L1 extends in the longitudinal direction DL, passing through both ends of the inner hole 112 in the width direction DW, which is perpendicular to the longitudinal direction DL in which the outer hole 111 and the inner hole 112 are aligned. The second region a2 is a region excluding the first region a1. The second region a2 is a region closer to the edge 113e of the first header 113a in the width direction DW than the inner hole 112. The second region a2 is a region between the first straight line L1 and the edge 113e of the first header 113a in the width direction DW.

[0130] FIG. 9 is a plan view illustrating the flow rate of a refrigerant in a heat transfer plate 500 according to the prior art. In FIG. 9, the thickness of the arrows indicates the flow rate of the refrigerant. In FIG. 9, components corresponding to those in the first heat transfer plate 110 are denoted by the same reference numerals. The first heat transfer plate 110 differs from the heat transfer plate 500 in that the first heat transfer plate 110 includes first protrusions 115a. As shown in FIG. 9, if the first protrusions 115a were not provided, some of the refrigerant flowing out of the outer holes 111 would be prevented by the inner holes 112 from proceeding linearly toward the first flow passages 210. Therefore, the flow rate of the first refrigerant on the recess 114 side of the inner holes 112 in the header 113 would be lower than the flow rate at other positions. As a result, there was a problem in that the flow rate of the first refrigerant was uneven in the first flow passages 210, hindering the heat exchange efficiency.

[0131] FIG. 10 is a plan view illustrating the flow rate of the first refrigerant flowing into the first flow passage in the first heat transfer plate 110. In FIG. 10, the flow rate of the first refrigerant is indicated by the thickness of the arrows. The flow of the first refrigerant that flows out of the outer holes 111 and into the first header 113a is controlled by the first protrusions 115a before entering the first flow passage 210. Specifically, in the first header 113a, the density of the first protrusions 115a formed in the first region a1 is lower than the density of the first protrusions 115a formed in the second region a2. Therefore, the first refrigerant is prevented from flowing smoothly by the first protrusions 115a. As a result, more of the first refrigerant flows into the first region a1, which is located on the recess 114 side of the inner hole 112, than into the second region a2. This allows the first heat exchanger 100 to prevent unevenness in the flow rate of the refrigerant flowing into the first flow passage 210, which functions as a heat transfer region.

[0132] (3-2) The number of first protrusions 115a formed in the first region a1 per unit area may be different from the number of first protrusions 115a formed in the second region a2 per unit area.

[0133] (3-3) In a planar view of the first heat transfer plate 110, the density of the first protrusions 115a formed in the first region a1 between the second straight line L2 passing through the center of the inner hole 112 and extending in the width direction DW and the edge 114e of the recess 114 facing the inner hole 112 may be smaller than the density of the first protrusions 115a formed in the second region a2 (in other words, the first part a21 of the second region a2) between the second straight line L2 and the edge 114e of the recess 114 facing the inner hole 112.

[0134] This feature promotes the flow of the first refrigerant from the second region a2 to the first region a1, thereby enabling the first heat exchanger 100 to further suppress bias in the flow rate of the first refrigerant flowing into the first flow path 210, which functions as a heat transfer region.

[0135] (3-4) When viewed in a plane of the first heat transfer plate 110, the density of the first protrusions 115a formed in the first region a1 between the third straight line L3 passing through the center of the outer hole 111 and extending in the width direction DW and the edge 114e of the recess 114 facing the inner hole 112 may be smaller than the density of the first protrusions 115a formed in the second region a2 (in other words, the first part a21 and the second part a22 of the second region a2) between the third straight line L3 and the edge 114e of the recess 114 facing the inner hole 112.

[0136] This feature promotes the flow of the first refrigerant from the second region a2 to the first region a1, thereby enabling the first heat exchanger 100 to further suppress bias in the flow rate of the first refrigerant flowing into the first flow path 210, which functions as a heat transfer region.

[0137] (3-5) In a planar view of the first heat transfer plate 110, the density of the first protrusions 115a formed in the second region a2 between the third straight line L3 and the edge 113e of the first header 113a facing the outer hole 111 (in other words, the third part a23 of the second region a2) may be smaller than the density of the first protrusions 115a formed in the second region a2 between the third straight line L3 and the edge 114e of the recess 114 facing the inner hole 112 (in other words, the first part a21 and the second part a22 of the second region a2).

[0138] (3-6) The first heat transfer plate 110 may further include a second header 113b formed to sandwich the recess 114 together with the first header 113a and to surround the outer hole 111 and the inner hole 112 in a plan view of the first heat transfer plate 110. The second header 113b may have a plurality of second protrusions 115b formed thereon. The second header 113b may be formed so as to communicate the first communication passage 161 with the recess 114 and not to communicate the second communication passage 162 with the recess 114. In a plan view of the first heat transfer plate 110, the density of the second protrusions 115b formed in the first region a1 may be lower than the density of the second protrusions 115b formed in the second region a2.

[0139] (3-7) The second protrusion 115b may be disposed at a position symmetrical to the first protrusion 115a with the recess 114 interposed therebetween.

[0140] (3-8) The second heat transfer plate 130 may have a third header 133a formed to surround the inner hole 132 in a plan view of the second heat transfer plate 130. The third header 133a may have a plurality of third protrusions 135a formed thereon. The third header 133a may be formed so as to connect the second communication passage 162 and the recess 134 and not connect the first communication passage 161 and the recess 134. In the third header 133a, the density of the third protrusions 135a formed in the third region a3 may be greater than the density of the third protrusions 135a formed in the fourth region a4. The third region a3 is a region between two fourth straight lines L4 in a plan view of the second heat transfer plate 130. The fourth straight line L4 extends in the longitudinal direction DL, passing through both ends of the inner hole 132 in the width direction DW, which is perpendicular to the longitudinal direction DL in which the outer hole 111 and the inner hole 132 are aligned. The fourth region a4 is the region excluding the third region a3.

[0141] FIG. 11 is a plan view illustrating the flow rate of the second refrigerant flowing into the second flow passage in the second heat transfer plate 130. In FIG. 11, the flow rate of the second refrigerant is indicated by the thickness of the arrows. The flow of the second refrigerant that flows out of the outer holes 131 and into the third header 133a is controlled by the third protrusions 135a before entering the second flow passage 220. Specifically, in the third header 133a, the density of the third protrusions 135a formed in the third region a3 is greater than the density of the third protrusions 135a formed in the fourth region a4. Therefore, the smooth flow of the second refrigerant is inhibited by the third protrusions 135a. As a result, more of the second refrigerant flows into the fourth region a4, which is the region excluding the recess 134 side of the outer holes 131, than into the third region a3. This allows the first heat exchanger 100 to suppress bias in the flow rate of the second refrigerant flowing into the second flow passage 220, which functions as a heat transfer region.

[0142] (3-9) The second heat transfer plate 130 may further include a fourth header 133b formed to sandwich the recess 134 together with the third header 133a and to surround the inner hole 132 in a plan view of the second heat transfer plate 130. The fourth header 133b may have a plurality of fourth protrusions 135b formed thereon. The fourth header 133b may be formed so as to communicate between the second communication passage 162 and the recess 134 and not to communicate between the first communication passage 161 and the recess 134. In the fourth header 133b, the density of the third protrusions 135a formed in the third region a3 may be greater than the density of the fourth protrusions 135b formed in the fourth region a4 in a plan view of the second heat transfer plate 130.

[0143] (3-10) The inner diameter of the first communication passage 161 may be larger than the inner diameter of the second communication passage 162.

[0144] (3-11) The direction in which the first fluid flows through the first flow path 210 may be opposite to the direction in which the second fluid flows through the second flow path 220 in a plan view of the multiple plates.

[0145] (3-12) The refrigeration device 1 includes a first heat exchanger 100 .

[0146] Since the first heat exchanger 100 suppresses imbalance in the flow rate of the refrigerant and performs heat exchange efficiently, the refrigeration device 1 can achieve highly efficient operation.

[0147] (4) Variations (4-1) Variation 1 The difference in density between the protrusions 115 and 135 may be achieved by varying the average size of the protrusions 115 and 135 when the first heat transfer plate 110 and the second heat transfer plate 130 are viewed in plan.

[0148] In the first heat exchanger 100 according to Modification 1, the number of protrusions 115 per unit area is the same, and the average size of the protrusions 115 formed in the first region a1 in a plan view of the first heat transfer plate 110 is smaller than the average size of the protrusions 115 formed in the second region a2 in a plan view of the first heat transfer plate 110. Furthermore, in the first heat exchanger 100 according to Modification 1, the number of protrusions 135 per unit area is the same, and the average size of the protrusions 135 formed in the third region a3 in a plan view of the second heat transfer plate 130 is larger than the average size of the protrusions 135 formed in the fourth region a4 in a plan view of the second heat transfer plate 130.

[0149] Fig. 12 is a plan view of the first heat transfer plate 110, showing the arrangement of the protrusions 115 in the first heat exchanger 100 according to Modification 1. Fig. 13 is a plan view of the second heat transfer plate 130, showing the arrangement of the protrusions 135 in the first heat exchanger 100 according to Modification 1.

[0150] (4-2) Variation 2 The first protrusion 115a does not have to be arranged symmetrically with the second protrusion 115b across the recess 114. Furthermore, the third protrusion 135a does not have to be arranged symmetrically with the fourth protrusion 135b across the recess 134.

[0151] (4-3) Variation 3 In the first heat exchanger 100 according to the second modification, the second header 113b of the first heat transfer plate 110 may have the second protrusions 115b formed at a constant density in a plan view of the first heat transfer plate 110. Similarly, the fourth header 133b of the second heat transfer plate 130 may have the third protrusions 135a formed at a constant density in a plan view of the second heat transfer plate 130.

[0152] (4-4) Variation 4 The inner diameter of the first communication passage 161 may be smaller than the inner diameter of the second communication passage 162. In other words, the inner diameter of the outer holes 111, 121, 131 may be smaller than the inner diameter of the inner holes 112, 122, 132.

[0153] (4-5) Variation 5 Fig. 14 is a cross-sectional view showing the structure of the first flow paths 210 and the second flow paths 220 in the first heat exchanger 100 according to Modification 5. As shown in Fig. 8, in the first heat exchanger 100 according to Modification 5, the first heat transfer plates 110 and the second heat transfer plates 130 are alternately stacked with partition walls 170, instead of the partition walls 120, sandwiched therebetween.

[0154] The partition wall 170 differs from the partition wall 120 in that grooves 171 are formed on the surface of the partition wall 170. As shown in Fig. 14 , the grooves 171 are formed to face the grooves 114a when the partition wall 170 is stacked on the first heat transfer plate 110, thereby constituting the first flow paths 210. The grooves 171 are also formed to face the grooves 134a when the partition wall 170 is stacked on the second heat transfer plate 130, thereby constituting the second flow paths 220.

[0155] The first flow path 210 is formed by stacking the partition wall 170, in which the groove 171 is formed, on the first heat transfer plate 110, and closing the opening of the groove 114a with the groove 171. The second flow path 220 is formed by stacking the partition wall 170 on the second heat transfer plate 130, and closing the opening of the groove 114a with the groove 171.

[0156] Although not limited thereto, the grooves 114a are formed by etching. The cross-sectional shapes of the grooves 114a, 134a, and 171 shown in FIG. 14 are merely examples, and they may also be semicircular as shown in FIG.

[0157] (4-6) Variation 6 Fig. 15 is a cross-sectional view showing the structure of the first flow paths 210 and the second flow paths 220 in the first heat exchanger 100 according to Modification 6. As shown in Fig. 15, in the first heat exchanger 100 according to Modification 6, the first heat transfer plate 110 further has inner fins 116. Furthermore, the second heat transfer plate 130 further has inner fins 136. Furthermore, the first heat transfer plates 110 and the second heat transfer plates 130 are stacked alternately with spacers 123 sandwiched between them instead of the partition walls 120.

[0158] The inner fins 116, 136 are plate-like members having a corrugated cross section. The corrugations of the inner fins 116, 136 are formed so that the peaks of the corrugations extend along the longitudinal direction DL in a plan view.

[0159] Similar to the recessed portion 114 of the first heat exchanger 100 according to the first embodiment, the inner fin 116 is disposed in the center in the longitudinal direction DL of the first heat transfer plate 110. Moreover, the outer edge of the inner fin 116 is formed in a rectangular shape when the first heat transfer plate 110 is seen in a plan view.

[0160] Similar to the recessed portion 134 of the first heat exchanger 100 according to the first embodiment, the inner fin 136 is disposed in the center in the longitudinal direction DL of the second heat transfer plate 130. Moreover, the outer edge of the inner fin 136 is formed in a rectangular shape when the second heat transfer plate 130 is seen in a plan view.

[0161] The spacers 123 are disposed on the edges of the first heat transfer plate 110 and the second heat transfer plate 130, and form spaces in which the inner fins 116, 136 are disposed.

[0162] In the first heat exchanger 100 according to the sixth modification, the recesses 114 of the first heat transfer plate 110 are formed by a plurality of valleys 116a formed in the inner fins 116. By stacking the second heat transfer plate 130 on the first heat transfer plate 110, a first flow path 210 is formed between the valleys 116a and the second heat transfer plate 130 facing the inner fins 116. Similarly, in the first heat exchanger 100 according to the sixth modification, the recesses 134 of the second heat transfer plate 130 are formed by a plurality of valleys 136a formed in the inner fins 136. By stacking the first heat transfer plate 110 on the second heat transfer plate 130, a second flow path 220 is formed between the valleys 136a and the first heat transfer plate 110 facing the inner fins 136.

[0163] (4-7) Variation 7 FIG. 16 is a cross-sectional view showing the structure of the first flow paths 210 and the second flow paths 220 in a first heat exchanger 100 according to Modification 7. As shown in FIG. 16, in the first heat exchanger 100 according to Modification 7, the first heat transfer plates 110 and the second heat transfer plates 130 are alternately stacked without any partition walls 120 between them. The first heat transfer plate 110 has a plurality of linear grooves 114a formed along the longitudinal direction DL on the surface opposite to the recessed portion 114. The grooves 114a are formed so as to face the grooves 134a of the second heat transfer plate 130 when the first heat transfer plate 110 and the second heat transfer plate 130 are stacked together, thereby forming the second flow paths 220. Similarly, the second heat transfer plate 130 has a plurality of linear grooves 134a formed along the longitudinal direction DL on the surface opposite to the recessed portion 134. The grooves 134a are formed to face the grooves 114a of the first heat transfer plate 110 and to form the first flow paths 210 when the first heat transfer plate 110 and the second heat transfer plate 130 are stacked together.

[0164] 17 is a cross-sectional view showing the structure of the first flow path 210 and the second flow path 220 in a first heat exchanger 100 according to another example of Modification 7. As shown in FIG. 17, in the first heat exchanger 100 according to Modification 7, a partition wall 120 may be stacked between the first heat transfer plate 110 and the second heat transfer plate 130.

[0165] Although not limited thereto, the grooves 114a are formed by etching. The cross-sectional shapes of the grooves 114a, 134a, and 171 shown in Figures 16 and 14 are merely examples, and they may also be semicircular as shown in Figure 3.

[0166] (4-8) Variation 8 The fluid that the first heat exchanger 100 exchanges heat with is not limited to refrigerants such as carbon dioxide and propane, but may also be water.

[0167] However, in the first heat exchanger 100, the bias in the flow rate of the refrigerant flowing into the first flow path 210 can be more effectively suppressed when using the refrigerant rather than water.

[0168] Furthermore, even when a refrigerant is used, the first heat exchanger 100 can more effectively suppress imbalances in the flow rate of the refrigerant flowing into the first flow path 210 when a refrigerant that becomes a two-phase state in the first heat exchanger 100 is used.

[0169] (4-9) Variation 9 The shape of the protrusions 115, 135 in plan view is not limited to a circle. Figures 18, 19, and 20 are plan views of the first heat transfer plate 110 showing other examples of the protrusions 115. The shape of the protrusions 115 in plan view may be any of a triangle (see Figure 18), a rectangle (see Figure 19), and a teardrop (see Figure 20). Although not shown, the protrusions 135 may also have a similar shape. Furthermore, the protrusions 115, 135 may have different shapes.

[0170] <Conclusion> Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims. [Explanation of symbols]

[0171] 1: Refrigeration equipment 3:Third area 4: 4th protrusion 110: First heat transfer plate (first plate) 111: Outer hole (first through hole) 112: Inner hole (second through hole) 113: Header 113a: First header 113b: Second header 113e: edge 114: Recess 114e: edge 115: Protrusion 115a: 1st protrusion 115b: 2nd protrusion 116: Inner fin 116a: Tanibe 130: Second heat transfer plate (second plate) 131: Outer hole (first through hole) 132: Inner hole (second through hole) 133: Header 133a: Third header 133b: 4th header 133e :Edge 134: Recess 134e :Edge 135: Protrusion 135a: 3rd protrusion 135b: 4th protrusion 136: Inner fin 136a: Tanibe 161: 1st communication passage 162:Second communication passage 210: First flow path 220: Second flow path 410: First flow path 420: Second flow path a1 :1st area a2 :Second area a21 :1st part a22: 2nd part a23 :3rd part a3: 3rd area a4: 4th area DT: Thickness direction (first direction) DL: Longitudinal direction (2nd direction, 4th direction) DW: Width direction (3rd direction, 5th direction) L1: 1st straight line L2: 2nd straight line L3: 3rd straight line L4: 4th straight line [Prior art documents] [Patent documents]

[0172] [Patent Document 1] Patent No. 2024-012151

Claims

1. A plate heat exchanger in which a plurality of plates are stacked in a first direction (DT), a first communication passage (161) through which a first fluid flows along the first direction (DT); a second communication passage (162) through which a second fluid flows along the first direction (DT); a first flow path (210) that causes the first fluid flowing through the first communication path (161) to flow along the surface of a first plate (110) included in the plurality of plates; a second flow path (220) that causes the second fluid flowing through the second communication path (162) to flow along the surface of a second plate (130) included in the plurality of plates; Equipped with The first plate (110) and the second plate (130) a recess (114) that forms the first flow path (210) or the second flow path (220) by being blocked by another plate included in the plurality of plates stacked adjacently; two first through holes (111, 131) that constitute a part of the first communication passage (161) and are formed so as to sandwich the recess (114) when viewed from above of the plurality of plates; two second through holes (112, 132) that constitute a part of the second communication passage (162) and are formed between the first through holes (111, 131) and the recesses (114) in a plan view of the plurality of plates; The first plate (110) comprises: The first plate (110) has a first header (113a) formed so as to surround the first through-hole (111, 131) and the second through-hole (112, 132) in a plan view, The first header (113a) is A plurality of first protrusions (115a) are formed, The first communication passage (161) is formed to communicate with the recess (114), and the second communication passage (162) is formed to not communicate with the recess (114), In a plan view of the first plate (110), the density of the plurality of first protrusions (115 a) formed in a first region (a1) between two first straight lines (L1) extending in the second direction (DL) passing through both ends of the second through holes (112, 132) in a third direction (DW) perpendicular to the second direction (DL) in which the first through holes (111, 131) and the second through holes (112, 132) are aligned is lower than the density of the plurality of first protrusions (115 a) formed in a second region (a2) which is a region excluding the first region (a1). heat exchanger.

2. The average size of the first protrusions (115a) formed in the first region (a1) in a plan view of the first plate (110) is: The first protrusions (115a) formed in the second region (a2) have a size different from the average size of the first plate (110) in a plan view. The heat exchanger of claim 1 .

3. The number of the first protrusions (115a) formed in the first region (a1) per unit area is the number per unit area of ​​the first protrusions (115a) formed in the second region (a2) is different from that of the first protrusions (115a), The heat exchanger of claim 1 .

4. In a plan view of the first plate (110), the density of the first protrusions (115a) formed in the first region (a1) between a second straight line (L2) passing through the center of the second through hole (112, 132) and extending in the third direction (DW) and an edge (114e) of the recess (114) facing the second through hole (112, 132) is the density of the first protrusions (115a) formed in the second region (a2) between the second straight line (L2) and an edge (114e) of the recess (114) facing the second through hole (112, 132) is smaller than the density of the first protrusions (115a) formed in the second region (a2) between the second straight line (L2) and an edge (114e) of the recess (114) facing the second through hole (112, 132), The heat exchanger of claim 1 .

5. In a plan view of the first plate (110), the density of the first protrusions (115a) formed in the first region (a1) between a third straight line (L3) passing through the center of the first through hole (111, 131) and extending in the third direction (DW) and an edge (114e) of the recess (114) facing the second through hole (112, 132) is: the density of the first protrusions (115a) formed in the second region (a2) between the third straight line (L3) and the edge (114e) of the recess (114) facing the second through hole (112, 132), 5. The heat exchanger according to claim 4.

6. In a plan view of the first plate (110), the density of the first protrusions (115a) formed in the second region (a2) between the third straight line (L3) and the edge (113e) of the first header (113) facing the first through-holes (111, 131) is: the density of the first protrusions (115a) formed in the second region (a2) between the third straight line (L3) and the edge (114e) of the recess (114) facing the second through hole (112, 132), 6. The heat exchanger according to claim 5.

7. The first plate (110) comprises: The first plate (110) further includes a second header (113b) formed to sandwich the recess together with the first header and to surround the first through hole (111, 131) and the second through hole (112, 132) in a plan view, The second header (113b) is A plurality of second protrusions (115b) are formed, The first communication passage (161) is formed to communicate with the recess (114), and the second communication passage (162) is formed to not communicate with the recess (114), In a plan view of the first plate, the second protrusions (115b) are formed at a constant density. The heat exchanger of claim 1 .

8. The first plate (110) comprises: The first plate (110) further includes a second header (113b) formed to sandwich the recess together with the first header and to surround the first through hole (111, 131) and the second through hole (112, 132) in a plan view, The second header (113b) is A plurality of second protrusions (115b) are formed, The first communication passage (161) is formed to communicate with the recess (114), and the second communication passage (162) is formed to not communicate with the recess (114), In a plan view of the first plate (110), the density of the second protrusions (115b) formed in the first region (a1) is lower than the density of the second protrusions (115b) formed in the second region (a2). The heat exchanger of claim 1 .

9. The second protrusion (115b) is The first protrusion (115a) and the recess (114) are disposed at positions symmetrical to each other with the first protrusion (115a) and the recess (114) interposed therebetween.

9. The heat exchanger of claim 8.

10. The second plate (130) The second plate (130) has a third header (133a) formed so as to surround the second through hole (112, 132) in a plan view, The third header (133a) is A plurality of third protrusions (135a) are formed, The second communication passage (162) is formed to communicate with the recess (134), and the first communication passage (161) is formed to not communicate with the recess (134), In a plan view of the second plate (130), the density of the third protrusions (135 a) formed in a third region (a3) ​​between two fourth straight lines (L4) passing through both ends of the second through holes (112, 132) in a fifth direction (DW) perpendicular to the fourth direction (DL) in which the first through holes (131) and the second through holes (132) are aligned is greater than the density of the plurality of third protrusions (135 a) formed in a fourth region (a4) which is a region excluding the third region (a3). The heat exchanger of claim 1 .

11. The second plate (130) The second plate (130) further includes a fourth header (133b) formed to sandwich the recess (134) together with the third header (133a) and to surround the second through hole (132) in a plan view, The fourth header (133b) is A plurality of fourth projections (135b) are formed, the second communication passage (162) and the recess (134) are communicated with each other, and the first communication passage (161) and the recess (114) are not communicated with each other; In a plan view of the second plate (130), the fourth protrusions (135b) are formed at a constant density.

11. The heat exchanger of claim 10.

12. The second plate (130) The second plate (130) further includes a fourth header (133b) formed to sandwich the recess (134) together with the third header (133a) and to surround the second through hole (132) in a plan view, The fourth header (133b) is A plurality of fourth projections (135b) are formed, The second communication passage (162) is formed to communicate with the recess (134), and the first communication passage (161) is formed to not communicate with the recess (134), In a plan view of the second plate (130), the density of the fourth protrusions (135b) formed in the third region (a3) ​​is greater than the density of the fourth protrusions (135b) formed in the fourth region (a4).

11. The heat exchanger of claim 10.

13. The inner diameter of the first communication passage (161) is The inner diameter of the second communication passage (162) is larger than the inner diameter of the second communication passage (162). The heat exchanger of claim 1 .

14. The inner diameter of the first communication passage (161) is The inner diameter of the second communication passage (162) is smaller than the inner diameter of the second communication passage (162). The heat exchanger of claim 1 .

15. The direction in which the first fluid flows through the first flow path (210) is In a plan view of the plurality of plates, the direction of the second fluid flows through the second flow path (220). The heat exchanger of claim 1 .

16. The first plate (110) comprises: Further having an inner fin (116), The recess (114) A valley portion (116a) of the inner fin (116), The heat exchanger of claim 1 .

17. A heat exchanger according to any one of claims 1 to 15, Refrigeration device (1).

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