Plate and shell heat exchanger

Abstract

A plate-shell heat exchanger has multiple refrigerant flow paths (41) for refrigerant flow and multiple heat medium flow paths (42) for heat medium flow in a plate bundle (40) with heat transfer plates (50a, 50b) sandwiched adjacently. The heat transfer plates (50a, 50b) have a first connecting hole (52a, 52b) and a second connecting hole (54a, 54b). In the heat medium flow path (42), a guide portion (70) is provided. The guide portion (70) is provided to pass through the first connecting hole (52a, 52b) and the second connecting hole (54a, 54b), and guides the heat medium flowing from the first connecting hole (52a, 52b) into the heat medium flow path (42) to the side of the heat transfer plates (50a, 50b).

Description

Technical Field

[0001] This disclosure relates to a plate-and-shell heat exchanger. Background Technology

[0002] Patent Document 1 discloses a plate-and-shell heat exchanger (heat exchanger device) having a plate assembly consisting of multiple heat exchange plates and a housing for housing the plate assembly. This heat exchanger is a flooded heat exchanger in which liquid refrigerant is stored in the lower space of the housing. The liquid refrigerant in the housing evaporates by exchanging heat with a fluid flowing in the plate assembly. The evaporated refrigerant flows out from the upper part of the housing to the outside.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 2006-527835 Summary of the Invention

[0006] -The technical problem the invention aims to solve-

[0007] In the heat exchange plate of Patent Document 1, when the inlet flow path is located at the top and the outlet flow path is located at the bottom, the fluid flows from top to bottom. Because heat exchange occurs during the flow, the temperature of the fluid near the outlet flow path is relatively low. Because the temperature difference between the refrigerant and the heat exchange plate is relatively smaller at the bottom, the amount of heat exchange between the refrigerant and the fluid is reduced, thus decreasing the performance of the heat exchanger.

[0008] The purpose of this disclosure is to improve the performance of plate heat exchangers.

[0009] - Technical solutions used to solve technical problems -

[0010] The first aspect relates to a plate-and-shell heat exchanger comprising a shell 20 and a plate bundle 40, the shell 20 forming an internal space 21, the plate bundle 40 having a plurality of heat transfer plates 50a, 50b that overlap and are joined to each other in a transverse direction and are housed within the internal space 21 of the shell 20, the plate-and-shell heat exchanger causing refrigerant flowing into the internal space 21 of the shell 20 to evaporate, and in the plate bundle 40, a plurality of refrigerant flow paths 41 and a plurality of heat medium flow paths 42 are formed adjacent to the heat transfer plates 50a, 50b, the refrigerant flow paths 41 communicating with the internal space 21 of the shell 20 and supplying refrigerant flow, the heat medium flow paths 42 being disconnected from the internal space 21 of the shell 20 and supplying refrigerant flow. A heat transfer plate 50a, 50b has a first connecting hole 52a, 52b and a second connecting hole 54a, 54b. The first connecting holes 52a, 52b are connected to the heat transfer medium flow path 42 and introduce heat transfer medium into the heat transfer medium flow path 42. The second connecting holes 54a, 54b are formed below the first connecting holes 52a, 52b and are connected to the heat transfer medium flow path 42 and lead out heat transfer medium from the heat transfer medium flow path 42. A guide portion 70 is provided in the heat transfer medium flow path 42. The guide portion 70 is provided in such a way that it passes through the first connecting holes 52a, 52b and the second connecting holes 54a, 54b and guides the heat transfer medium flowing into the heat transfer medium flow path 42 from the first connecting holes 52a, 52b to the side of the heat transfer plate 50a, 50b.

[0011] In the first aspect, the hot medium flowing in the hot medium flow path 42 flows to the side of the heat transfer plates 50a and 50b under the guidance of the guide portion 70, and then flows to the second connecting holes 54a and 54b. Compared with the case without the guide portion 70, it is possible to suppress the flow of the hot medium in the shortest path connecting the first connecting holes 52a and 52b and the second connecting holes 54a and 54b.

[0012] Secondly, based on the first aspect, the lower end of the guide portion 70 is located below the upper end of the second connecting holes 54a and 54b.

[0013] In the second aspect, based on the first aspect, the hot medium flowing in the hot medium flow path 42, guided by the guide portion 70, flows to the sides of the heat transfer plates 50a and 50b, and then flows around the lower end of the guide portion 70 to the second connecting holes 54a and 54b. Compared to the case without the guide portion 70, the hot medium reaches the lower part of the heat transfer plates 50a and 50b with its temperature not decreasing significantly. This ensures that the temperature difference between the refrigerant and the hot medium is maintained at the lower part of the heat transfer plates 50a and 50b. As a result, the reduction in heat exchange efficiency can be suppressed, thereby improving the performance of the heat exchanger 10.

[0014] Thirdly, based on the first or second aspect, the distance between the lower end of the second connecting hole 54a, 54b and the lower end of the heat transfer plate 50a, 50b is greater than the distance between the upper end of the first connecting hole 52a, 52b and the upper end of the heat transfer plate 50a, 50b.

[0015] In the third aspect, the second connecting holes 54a and 54b are formed at a position higher than the lower ends of the heat transfer plates 50a and 50b. Therefore, the fluid flowing into the first connecting holes 52a and 52b is guided by the guide portion 70 to flow near the lower ends of the heat transfer plates 50a and 50b, and then rises towards the second connecting holes 54a and 54b. This flow pattern of the heat medium ensures that the temperature of the heat medium in the lower part of the heat transfer plates 50a and 50b is higher than the temperature of the heat medium near the second connecting holes 54a and 54b. As a result, heat exchange between the heat medium and the refrigerant is promoted in the lower part of the heat transfer plates 50a and 50b, thereby improving the performance of the heat exchanger 10.

[0016] Fourthly, based on the first to third aspects, the height of the center of the second connecting holes 54a and 54b is higher than the height of the lower end of the guide portion 70.

[0017] In the fourth aspect, the heat medium flowing into the second connecting holes 54a and 54b flows from below the second connecting holes 54a and 54b. Therefore, at the lower end of the heat transfer plates 50a and 50b, the flow rate of the heat medium increases, thereby suppressing the decrease in heat exchange efficiency at the lower end of the heat transfer plates 50a and 50b.

[0018] The fifth aspect is based on any one of the first to fourth aspects, wherein the guide portion 70 is a plate component 75 provided through a plurality of heat transfer plates 50a, 50b, the plurality of heat transfer plates 50a, 50b overlapping and joined together.

[0019] In the fifth aspect, the guide portion 70 can be formed from a plate member 75. The guide portion 70 can be provided on an existing heat transfer plate using the plate member 75.

[0020] The sixth aspect is based on any one of the first to fourth aspects, wherein the guide portion 70 is composed of protrusions 57a, 57b or recesses 56a, 56b formed on the heat transfer plates 50a, 50b.

[0021] In the sixth aspect, the guide portion 70 can be easily formed by stamping or the like. As a result, since the heat transfer plates 50a and 50b can be manufactured using the same mold, the plate bundle 40 equipped with the guide portion can be easily manufactured. Attached Figure Description

[0022] Figure 1 This is a front view of the heat exchanger involved in the embodiment and a simplified diagram showing the I-I cross section of the front view;

[0023] Figure 2 It is a simplified diagram showing a portion of the longitudinal section of the plate bundle after magnification;

[0024] Figure 3 These are simplified front view diagrams of the first and second boards;

[0025] Figure 4 This is a simplified diagram showing the flow of the heat medium within the plate bundle;

[0026] Figure 5 This is a simplified diagram showing the flow of the heat medium on the heat transfer plate;

[0027] Figure 6 The heat exchanger involved in the first variation is equivalent to Figure 5 The image;

[0028] Figure 7 The heat exchanger involved in the second variation is equivalent to Figure 5 The image;

[0029] Figure 8 This is a simplified front view of the heat transfer plate involved in the third variation;

[0030] Figure 9 The heat exchanger involved in the fourth variation is equivalent to Figure 3 The image;

[0031] Figure 10 The heat exchanger involved in the fifth variation is equivalent to Figure 3 The image. Detailed Implementation

[0032] The following description of this embodiment is based on the accompanying drawings. It should be noted that the following embodiments are essentially preferred examples and are not intended to limit the scope of the invention, its applications, or its uses.

[0033] (Implementation Method)

[0034] <Overall Composition>

[0035] The plate-and-shell heat exchanger 10 (hereinafter referred to as "heat exchanger") of this embodiment is connected to the refrigerant circuit (not shown) of the refrigeration device. In this refrigeration device, the refrigerant, which has been compressed by the compressor, dissipates heat in the condenser (radiator) and then has its pressure reduced by a pressure reducing mechanism. The depressurized refrigerant evaporates in the heat exchanger 10, which functions as an evaporator, and is then drawn into the compressor. As described above, a refrigeration cycle occurs in the refrigerant circuit of the refrigeration device.

[0036] like Figure 1 As shown, the heat exchanger 10 has a housing 20 and a plate bundle 40. The plate bundle 40 is housed within the internal space 21 of the housing 20. Liquid refrigerant flows into the internal space 21 of the housing 20. The liquid refrigerant exchanges heat with a heat medium flowing within the plate bundle 40. As described above, the heat exchanger 10 functions as an evaporator by evaporating the refrigerant flowing into the internal space 21 of the housing 20. It should be noted that, for example, water and antifreeze can be used as heat media.

[0037] -case-

[0038] The casing 20 is a cylindrical, sealed container with a relatively long transverse length. The casing 20 has a body 20a, a first sidewall 20b, and a second sidewall 20c. The body 20a is cylindrical. The first sidewall 20b is circular and closes the left end of the body 20a. The second sidewall 20c is circular and closes the right end of the body 20a. The casing 20, using the body 20a, the first sidewall 20b, and the second sidewall, forms an internal space 21. Liquid refrigerant is stored in the internal space 21.

[0039] The body section 20a has a refrigerant inlet 32 ​​and a refrigerant outlet 33. The refrigerant inlet 32 ​​is located at the bottom of the body section 20a. Refrigerant is introduced into the internal space 21 through the refrigerant inlet 32. The refrigerant outlet 33 is located at the top of the body section 20a. After evaporation in the internal space 21, the refrigerant is led out of the casing 20 through the refrigerant outlet 33. The refrigerant inlet 32 ​​and the refrigerant outlet 33 are connected to the refrigerant circuit via pipes.

[0040] A heat medium inlet 23 and a heat medium outlet 24 are provided on the first sidewall 20b. The heat medium inlet 23 and the heat medium outlet 24 are tubular components.

[0041] The heat medium inlet 23 penetrates approximately the central portion of the first sidewall 20b. The heat medium inlet 23 is connected to the heat medium inlet path 43 of the plate bundle 40 and supplies heat medium to the plate bundle 40.

[0042] The heat medium outlet 24 penetrates the first sidewall 20b and is located approximately midway between the heat medium inlet 23 and the lower end of the first sidewall 20b. The heat medium outlet 24 is connected to the heat medium outlet path 44 of the plate bundle 40 and draws out the heat medium from the plate bundle.

[0043] -Plate bundle-

[0044] The plate bundle 40 is composed of multiple heat transfer plates 50a and 50b that are laterally overlapped and joined together. The plate bundle 40 is housed in the internal space 21 of the housing 20 with the heat transfer plates 50a and 50b stacked in a lateral direction.

[0045] like Figure 1 As shown in (a), the heat transfer plates 50a and 50b constituting the plate bundle 40 are approximately semi-circular plate-shaped components. The plate bundle 40 is arranged in the lower part of the internal space 21 of the housing 20 with the arcuate edges of the heat transfer plates 50a and 50b facing downwards. A protruding support portion (not shown) supporting the plate bundle 40 is provided on the inner surface of the housing 20. When the plate bundle 40 is housed in the internal space 21 of the housing 20, the plate bundle 40 is separated from the inner surface of the housing 20, and a gap 25 is formed between the downward-facing edges of the heat transfer plates 50a and 50b constituting the plate bundle 40 and the inner surface of the housing 20. An upper space 21a is formed on the upper part of the plate bundle 40 within the internal space 21.

[0046] like Figure 2 and Figure 3 As shown, in the plate bundle 40, first plates 50a and second plates 50b of different shapes are provided as heat transfer plates 50a and 50b. The plate bundle 40 includes a plurality of first plates 50a and a plurality of second plates 50b. In the plate bundle 40, the first plates 50a and second plates 50b are stacked alternately. In the following description, the first plates 50a and second plates 50b will be referred to as such. Figure 2 The left side is set as the surface, and Figure 3 The right side is designated as the back side.

[0047] <Heat medium inlet path, heat medium outlet path>

[0048] An inlet protrusion 51a and an outlet protrusion 53a are formed on the first plate 50a. Both the inlet protrusion 51a and the outlet protrusion 53a are circular portions that bulge towards the surface of the first plate 50a. Both the inlet protrusion 51a and the outlet protrusion 53a are formed at the center of the first plate 50a in the width direction. The inlet protrusion 51a is formed on the upper part of the first plate 50a. The outlet protrusion 53a is formed on the lower part of the first plate 50a. A first inlet hole 52a is formed at the center of the inlet protrusion 51a. The first inlet hole 52a corresponds to a first connecting hole in the first plate 50a. A first outlet hole 54a is formed at the center of the outlet protrusion 53a. Both the first inlet hole 52a and the first outlet hole 54a are circular holes that penetrate the first plate 50a along the thickness direction.

[0049] On the first plate 50a, a first distance d1 between the lower end of the first outlet hole 54a and the lower end of the first plate 50a is longer than a second distance d2 between the upper end of the first inlet hole 52a and the upper end of the first plate 50a. Furthermore, the first distance d1 is longer than a third distance d3 between the upper end of the first outlet hole 54a and the lower end of the first inlet hole 52a. In this embodiment, the first distance d1 is more than twice the third distance d3.

[0050] An inlet recess 51b and an outlet recess 53b are formed on the second plate 50b. Both the inlet recess 51b and the outlet recess 53b are circular portions that bulge towards the back side of the second plate 50b. Both the inlet recess 51b and the outlet recess 53b are formed at the center of the second plate 50b in the width direction. The inlet recess 51b is formed at the lower part of the second plate 50b. The outlet recess 53b is formed at the upper part of the second plate 50b. A second inlet hole 52b is formed at the center of the inlet recess 51b. A second outlet hole 54b is formed at the center of the outlet recess 53b. Both the second inlet hole 52b and the second outlet hole 54b are circular holes that penetrate the second plate 50b along the thickness direction.

[0051] On the second plate 50b, an inlet recess 51b is formed at a position corresponding to the inlet protrusion 51a of the first plate 50a, and an outlet recess 53b is formed at a position corresponding to the outlet protrusion 53a of the first plate 50a. Furthermore, on the second plate 50b, a second inlet hole 52b is formed at a position corresponding to the first inlet hole 52a of the first plate 50a, and a second outlet hole 54b is formed at a position corresponding to the first outlet hole 54a of the first plate 50a. The diameters of the first inlet hole 52a and the second inlet hole 52b are substantially equal to each other. The diameters of the first outlet hole 54a and the second outlet hole 54b are also substantially equal to each other.

[0052] As described above, the positions of the second outlet hole 54b and the second inlet hole 52b on the second plate 50b are the same as the positions of the first outlet hole 54a and the first inlet hole 52a on the first plate 50a, respectively. Strictly speaking, regarding the second outlet hole 54b, the distance between the lower end of the second outlet hole 54b and the lower end of the second plate 50b is the same as the first distance d1. The distance between the upper end of the second inlet hole 52b and the upper end of the second plate 50b is the same as the second distance d2.

[0053] In the plate bundle 40, the peripheral portion of each first plate 50a is welded to the peripheral portion of a second plate 50b adjacent to the back side of the first plate 50a over the entire circumference. Furthermore, in the plate bundle 40, the first inlet hole 52a of each first plate 50a overlaps with the second inlet hole 52b of the second plate 50b adjacent to the surface side of the first plate 50a, and the edges of the overlapping first inlet hole 52a and second inlet hole 52b are welded together over the entire circumference. The hole formed by the overlapping first inlet hole 52a and second inlet hole 52b corresponds to a first connecting hole. The first inlet hole 52a and second inlet hole 52b communicate with the heat medium flow path 42 to introduce heat medium into the heat medium flow path 42.

[0054] In the plate bundle 40, the first outlet hole 54a of each first plate 50a overlaps with the second outlet hole 54b of the second plate 50b adjacent to the surface side of the first plate 50a. The edges of the overlapping first outlet hole 54a and second outlet hole 54b are joined by welding over the entire circumference. The hole formed by the overlapping first outlet hole 54a and second outlet hole 54b corresponds to the second connecting hole. The first outlet hole 54a and second outlet hole 54b are formed below the first connecting holes 52a and 52b, and communicate with the heat medium flow path 42, leading the heat medium out of the heat medium flow path 42.

[0055] In the plate bundle 40, a heat medium introduction path 43 is formed by the inlet protrusion 51a and the first inlet hole 52a of each first plate 50a, and the inlet recess 51b and the second inlet hole 52b of each second plate 50b. Furthermore, in the plate bundle 40, a heat medium outlet path 44 is formed by the outlet protrusion 53a and the first outlet hole 54a of each first plate 50a, and the outlet recess 53b and the second outlet hole 54b of each second plate 50b.

[0056] The heat medium inlet path 43 and the heat medium outlet path 44 are respectively passages extending along the stacking direction of the heat transfer plates 50a and 50b in the plate bundle 40. The heat medium inlet path 43 is a passage disconnected from the internal space 21 of the shell 20, and connects all heat medium flow paths 42 to the heat medium inlet 23. The heat medium outlet path 44 is a passage disconnected from the internal space 21 of the shell 20, and connects all heat medium flow paths 42 to the heat medium outlet 24.

[0057] <Refrigerant Flow Path, Heat Medium Flow Path>

[0058] In the plate bundle 40, multiple refrigerant flow paths 41 and multiple heat medium flow paths 42 are formed adjacent to each other, sandwiching heat transfer plates 50a and 50b. The refrigerant flow paths 41 and heat medium flow paths 42 are separated from each other by the heat transfer plates 50a and 50b. A first convex-concave pattern 62a and a second convex-concave pattern 62b are formed on the first plate 50a and the second plate 50b, respectively. The first convex-concave pattern 62a and the second convex-concave pattern 62b are obtained by repeatedly forming narrow, elongated ridge-like convex-concave patterns. Figure 3 As shown, the first concave-convex pattern 62a and the second concave-convex pattern 62b extend with their convex and concave edges relative to the horizontal direction X at a first angle α1 and a second angle α2, respectively. The first angle α1 and the second angle α2 are complementary angles. For example, when the first angle α1 is 45 degrees, the second angle α2 is 135 degrees. The first angle α1 ranges from 15 degrees to 75 degrees. The second angle α2 ranges from 165 degrees to 105 degrees.

[0059] In the first embossed pattern 62a, a first surface-side protrusion 55a bulging toward the surface side of the first plate 50a and a first back-side protrusion 57a ​​bulging toward the back side of the first plate 50a are alternately provided. In the second embossed pattern 62b, a second surface-side protrusion 57b bulging toward the surface side of the second plate 50b and a second back-side protrusion 55b bulging toward the back side of the second plate 50b are alternately provided.

[0060] The refrigerant flow path 41 is a flow path sandwiched between the surface of the first plate 50a and the back surface of the second plate 50b. The refrigerant flow path 41 communicates with the internal space 21 of the housing 20 and allows refrigerant to flow. Strictly speaking, the refrigerant flow path 41 is formed by a first flow path 45 and a first space M. The first flow path 45 is formed between the back surface of the first back side protrusion 57a ​​and the back surface of the second surface side protrusion 57b. The first space M is formed between the first surface side protrusion 55a and the second back side protrusion 55b. The first flow path 45 and the first space M are arranged alternately from the upper end to the lower end of the plate bundle 40. The upper and lower ends of the first flow path 45 communicate with the first space M. Adjacent first flow paths 45 in the vertical direction are connected through the first space M. The first flow path 45 and the first space M are open to the internal space 21.

[0061] The heat medium flow path 42 is a flow path sandwiched between the back surface of the first plate 50a and the surface of the second plate 50b. The heat medium flow path 42 is disconnected from the internal space 21 of the housing 20 and is a flow path through which the heat medium flows. Strictly speaking, the heat medium flow path 42 is formed by a second flow path 46 and a second space N. The second flow path 46 is formed between the back surface of the first surface-side protrusion 55a and the back surface of the second back surface protrusion 55b. The second space N is the space formed between the first back surface protrusion 57a ​​and the second surface-side protrusion 57b. The second flow path 46 and the second space N are repeatedly alternately arranged from the upper end to the lower end of the plate bundle 40. The upper and lower ends of the second flow path 46 communicate with the second space N. Adjacent second flow paths 46 in the vertical direction are connected through the second space N. The second flow path 46 and the second space N are disconnected from the internal space of the housing 20.

[0062] Guiding Department

[0063] like Figure 2 and Figure 3 As shown, a guide portion 70 is provided in the heat medium flow path 42. The guide portion 70 is provided so that it passes through the first connecting holes 52a, 52b and the second connecting holes 54a, 54b when viewed from the front of the heat transfer plates 50a, 50b. The guide portion 70 will be described in detail below.

[0064] The guide portion 70 is formed by a first linear flat portion 65a and a second linear flat portion 65b. Strictly speaking, the first linear flat portion is formed in a linear shape on the back side of the first plate 50a. The first linear flat portion 65a bulges towards the back side of the first plate 50a, and the top of the bulge is formed as a flat top. The second linear flat portion 65b is formed in a linear shape on the surface of the second plate 50b. The second linear flat portion 65b bulges towards the surface side of the second plate 50b, and the top of the bulge is formed as a flat top. When the first plate 50a and the second plate 50b are overlapped, the second linear flat portion 65b is formed at a position corresponding to the first linear flat portion 65a.

[0065] In the plate bundle 40, the first linear flat portion 65a of the first plate 50a overlaps with the second linear flat portion 65b of the second plate 50b adjacent to the back side of the first plate 50a, and the overlapping first linear flat portion 65a and second linear flat portion 65b are joined along the entire length direction by brazing or the like. The guide portion 70 is composed of the first linear flat portion 65a and the second linear flat portion 65b joined together.

[0066] The guide portion 70 has a first guide portion 70a and a second guide portion 70b. The first guide portion 70a is located at the midpoint between the lower ends of the first connecting holes 52a and 52b and the upper ends of the second connecting holes 54a and 54b, and is formed in a straight line along the width direction of the heat transfer plates 50a and 50b. The second guide portion 70b is formed in a straight line extending downward from each end of the first guide portion 70a. The guide portions 70 are arranged symmetrically with respect to the center line Y of the heat transfer plates 50a and 50b.

[0067] The first linear flat portion 65a of the first guide portion 70a is located between the first inlet hole 52a and the first outlet hole 54a of the first plate 50a, and is formed along the width direction of the first plate 50a. The first linear flat portion 65a of the first guide portion 70a is located between two adjacent first surface side protrusions 55a in the vertical direction.

[0068] The second linear flat portion 65b of the first guide portion 70a is located between the second inlet hole 52b and the second outlet hole 54b of the second plate 50b, and is formed along the width direction of the second plate 50b. The second linear flat portion 65b of the first guide portion 70a is located between two adjacent second back side protrusions 55b in the vertical direction. The length L1 of the first guide portion 70a is approximately half the length from one end to the other end of the heat transfer plates 50a and 50b.

[0069] The first linear flat portion 65a of the second guide portion 70b is formed such that it extends downward from each end of the first linear flat portion 65a on the back surface of the first plate 50a. The second linear flat portion 65b of the second guide portion 70b is formed such that it extends downward from each end of the first linear flat portion 65a on the surface of the second plate 50b. The length L2 of the second guide portion 70b is approximately one-third the length L1 of the first guide portion 70a. The lower end of the second guide portion 70b is located below the upper end of the second connecting holes 54a and 54b. Strictly speaking, the lower end of the second guide portion 70b is lower than the height of the center O of the second connecting holes 54a and 54b. More precisely, the lower end of the second guide portion 70b is located at approximately the midpoint between the center O of the second connecting holes 54a and 54b and the lower end of the second connecting holes 54a and 54b.

[0070] - Flow conditions of heat medium and refrigerant -

[0071] The following reference Figure 4 and Figure 5 Please describe in detail the flow of the heat medium and refrigerant within the heat exchanger 10. It should be noted that... Figure 4 The arrows shown indicate the direction of flow of the heat medium. Figure 5 This shows the state of liquid refrigerant stored inside the casing. Solid arrows indicate the flow direction of the heat medium, while dashed arrows indicate the flow direction of the refrigerant.

[0072] like Figure 4 As shown, the heat medium flows into the heat medium inlet 43 from the heat medium inlet 23. The heat medium flowing in the heat medium inlet 43 flows from the first connecting holes 52a and 52b toward the second connecting holes 54a and 54b in each heat medium flow path 42. Strictly speaking, the heat medium flowing in the heat medium inlet 43 flows into the second flow path 46. While flowing along the second flow path 46, the heat medium also flows through the second space N to the second flow path 46 adjacent to its lower side. As described above, the heat medium flows between the two ends of the heat transfer plates 50a and 50b, and flows downwards.

[0073] like Figure 5As shown, the hot medium flowing into the hot medium flow path 42 from the first connecting holes 52a and 52b is guided by the guide portion 70 to the sides of the heat transfer plates 50a and 50b. Strictly speaking, under the guidance of the first guide portion, the hot medium flowing in the hot medium flow path 42 cannot move downwards, but flows towards the sides of the heat transfer plates 50a and 50b. The hot medium flowing to the sides of the heat transfer plates 50a and 50b under the guidance of the first guide portion 70a flows along the second guide portion 70b towards the lower part of the heat transfer plates 50a and 50b. After passing the lower end of the second guide portion 70b, the hot medium flows towards the center of the heat transfer plates 50a and 50b in the width direction near the lower end of the heat transfer plates 50a and 50b. Around the second connecting holes 54a and 54b, fluids flowing from both sides of the second connecting holes 54a and 54b to the second connecting holes 54a and 54b, and fluids flowing from the lower side of the second connecting holes 54a and 54b to the second connecting holes 54a and 54b, are generated. Hot medium flowing from both sides and the lower side of the second connecting holes 54a and 54b flows into the second connecting holes 54a and 54b.

[0074] The flow of the refrigerant is described below. After passing through the expansion valve in the refrigerant circuit, the refrigerant flows to the heat exchanger 10. The liquid refrigerant flows from the refrigerant inlet 32 ​​into the internal space 21 of the housing 20. In the internal space 21, the liquid refrigerant is stored near the upper end of the plate bundle 40. The plate bundle 40 is immersed in the liquid refrigerant. The pressure of the refrigerant stored in the internal space 21 is relatively low. This low-pressure refrigerant exchanges heat with the heat medium flowing in the heat medium flow path 42. Strictly speaking, because the refrigerant flow path 41 and the heat medium flow path 42 are adjacent to each other, sandwiching the heat transfer plates 50a and 50b, the liquid refrigerant absorbs heat from the heat medium and evaporates when there is heat medium flowing in the heat medium flow path 42. The evaporated refrigerant moves from the refrigerant flow path 41 to the upper space 21a of the upper part of the internal space 21. The refrigerant in the upper space 21a flows out from the refrigerant outlet 33 into the refrigerant circuit.

[0075] - Features of the implementation method (1) -

[0076] In the heat medium flow path 42, a guide portion 70 is provided. The guide portion 70 is provided to pass through the first connecting holes 52a and 52b and the second connecting holes 54a and 54b, and guides the heat medium flowing into the heat medium flow path 42 from the first connecting holes 52a and 52b to the side of the heat transfer plates 50a and 50b.

[0077] In the prior art, within the plate bundle of a plate-and-shell heat exchanger, there are heat medium flow paths and refrigerant flow paths formed with heat transfer plates sandwiched adjacent to each other. Each heat transfer plate has two holes communicating with the heat medium flow paths, through which the heat medium flows from one hole to the other. When the heat medium flowing in from one hole moves towards the other hole along the shortest path connecting the two holes, it is difficult for the heat medium to distribute throughout the entire heat transfer plate. For example, at locations far from the holes, such as the ends of the heat transfer plates in the width direction, the heat medium tends to stagnate and thus ceases to exchange heat with the refrigerant. Therefore, the entire heat transfer plate cannot be effectively used for heat exchange, and only a small amount of heat exchange may be obtained.

[0078] In contrast, according to feature (1) of this embodiment, the heat medium flowing in the heat medium flow path 42 flows towards the side of the heat transfer plates 50a and 50b under the guidance of the first guide portion 70a. Then, the heat medium flows from the end of the first guide portion 70a along the second guide portion 70b. The heat medium flowing along the second guide portion 70b only contacts the outer region of the second guide portion 70b of the heat transfer plates 50a and 50b. Therefore, compared to the case where the heat medium contacts the entire width of the heat transfer plates 50a and 50b, the temperature of the heat medium reaching the lower end of the heat transfer plates 50a and 50b is higher. In this way, because the temperature difference between the refrigerant and the heat medium can be maintained at the lower part of the heat transfer plates 50a and 50b, the performance of the heat exchanger 10 can be improved. Moreover, the first connecting holes 52a and 52b are provided at the upper part of the heat transfer plates 50a and 50b. The heat medium flowing in from the first connecting holes 52a and 52b is guided by the first guide portion 70a and spreads across the sides of the heat transfer plates 50a and 50b. In this way, because the refrigerant can be promoted to evaporate on the upper part of the plate bundle 40, the amount of droplet liquid refrigerant flowing out of the heat exchanger along with the gaseous refrigerant can be reduced.

[0079] - Features of the implementation method (2) -

[0080] The lower end of the guide portion 70 is located below the upper end of the second connecting holes 54a and 54b.

[0081] According to this feature (2), the heat medium flows around the lower end of the guide portion 70 to the second connecting holes 54a and 54b. Compared with the case without the guide portion 70, the heat medium reaches the lower part of the heat transfer plates 50a and 50b with its temperature not decreasing much. In this way, the temperature difference between the refrigerant and the heat medium can be maintained at the lower part of the heat transfer plates 50a and 50b. As a result, the reduction in heat exchange efficiency can be suppressed, thereby improving the performance of the heat exchanger 10.

[0082] - Features of the implementation method (3) -

[0083] In the heat exchanger of this embodiment, the distance between the lower ends of the second connecting holes 54a and 54b and the lower ends of the heat transfer plates 50a and 50b is greater than the distance between the upper ends of the first connecting holes 52a and 52b and the upper ends of the heat transfer plates 50a and 50b.

[0084] According to this feature (3), the second connecting holes 54a and 54b are located at a certain distance from the lower ends of the heat transfer plates 50a and 50b. The heat medium flowing in the heat medium flow path 42 flows past the lower end of the second guide portion 70b and then rises to the second connecting holes 54a and 54b. Therefore, the temperature of the heat medium flowing near the lower ends of the heat transfer plates 50a and 50b is higher than the temperature of the heat medium flowing into the second connecting holes 54a and 54b. As a result, since the temperature drop of the heat medium is suppressed at the lower ends of the heat transfer plates 50a and 50b, the reduction in heat exchange efficiency of the heat exchanger 10 can be suppressed.

[0085] - Features of the implementation method (4) -

[0086] In the heat exchanger of this embodiment, the height of the center of the second connecting holes 54a and 54b is higher than the height of the lower end of the guide portion 70.

[0087] According to this feature (4), the heat medium flowing into the second connecting holes 54a and 54b flows from below the second connecting holes 54a and 54b. Therefore, the proportion of heat medium flowing into the second connecting holes 54a and 54b without passing near the lower end of the heat transfer plates 50a and 50b decreases, while the proportion of heat medium flowing near the lower end of the heat transfer plates 50a and 50b increases. Because the temperature of the heat medium flowing near the lower end is relatively high, the heat exchange efficiency between the refrigerant and the heat medium at the lower end of the heat transfer plates 50a and 50b can be improved.

[0088] - Features of the implementation method (5) -

[0089] The guide portion 70 is composed of protrusions 57a, 57b or recesses 58a, 58b formed on the heat transfer plates 50a, 50b.

[0090] Based on this feature (5), the guide portion 70 can be integrally formed by stamping or the like. This makes it easier to manufacture the heat transfer plates 50a and 50b and reduces the complexity of the manufacturing process of the plate bundle 40.

[0091] (Other implementation methods)

[0092] The heat exchanger 10 in the embodiment can also adopt the structure shown in the following modifications. It should be noted that the following modifications can be appropriately combined or replaced without affecting the function of the heat exchanger 10.

[0093] -First variation-

[0094] like Figure 6 As shown, in the first modified example, the heat transfer plates 50a and 50b are formed into approximately circular shapes. First connecting holes 52a and 52b are located near the upper ends of the heat transfer plates 50a and 50b. Second connecting holes 54a and 54b are located between the lower ends of the first connecting holes 52a and 52b and the center of the heat transfer plates 50a and 50b. The arrows in the figure indicate the flow direction of the heat medium.

[0095] In the first variation, the first guide portion 70a of the guide portion 70 is formed at an intermediate height position between the lower ends of the first connecting holes 52a and 52b and the upper ends of the second connecting holes 54a and 54b. The length L1 of the first guide portion 70a is approximately the same as the radius of the heat transfer plates 50a and 50b. The second guide portion 70b is formed to extend from each end of the first guide portion 70a to the lower part of the heat transfer plates 50a and 50b. Strictly speaking, the distance between the height position of the lower end of the second guide portion 70b and the height position of the lower end of the second connecting holes 54a and 54b is greater than the distance between the height position of the lower end of the second guide portion 70b and the height position of the lower end of the heat transfer plates 50a and 50b. Furthermore, the length L2 of the second guide portion 70b is longer than the length L1 of the first guide portion 70a.

[0096] According to this first modification, the heat medium flows from the first connecting holes 52a, 52b along the first guide portion 70a to the side, and then flows along the second guide portion to the lower part of the heat transfer plates 50a, 50b. The heat medium rises from the lower end of the second guide portion 70b to the second connecting holes 54a, 54b. In this way, because the distance from the first connecting holes 52a, 52b to the second connecting holes 54a, 54b can be sufficiently guaranteed, the reduction in heat exchange efficiency between the heat medium and the refrigerant can be suppressed. The distance the heat medium travels from the lower end of the second guide portion 70b to the second connecting holes 54a, 54b is relatively long. Therefore, the temperature difference between the heat medium at the lower end of the heat transfer plates 50a, 50b and the heat medium at the second connecting holes 54a, 54b can be sufficiently guaranteed. As a result, the temperature of the heat medium at the lower end of the heat transfer plates 50a, 50b is relatively high, thereby promoting heat exchange between the refrigerant and the heat medium in the lower part of the heat transfer plates 50a, 50b. Moreover, because the second connecting holes 54a and 54b are located at a relatively high position, they can store a relatively large amount of liquid refrigerant.

[0097] - Second variation -

[0098] like Figure 7 As shown, in Modified Example 2, the heat transfer plates 50a and 50b are formed into approximately elliptical shapes. First connecting holes 52a and 52b are located near the upper ends of the heat transfer plates 50a and 50b. The arrows in the figure indicate the flow direction of the heat medium.

[0099] The second connecting holes 54a and 54b are located directly below the first connecting holes 52a and 52b and are positioned near the center of the heat transfer plates 50a and 50b. The length L1 of the first guide portion 70a is approximately half the major diameter of the heat transfer plates 50a and 50b. The second guide portion 70b is formed to extend from each end of the first guide portion 70a to the lower part of the heat transfer plates 50a and 50b. Strictly speaking, the lower end of the second guide portion 70b is located at a position that ensures a relatively large distance between the height of this lower end and the height of the lower end of the second connecting holes 54a and 54b. Furthermore, the length L2 of the second guide portion 70b is greater than or equal to the length L1 of the first guide portion 70a.

[0100] According to this modified example 2, the heat medium flows from the first connecting holes 52a, 52b along the first guide portion 70a to the side, and then flows along the second guide portion to the lower part of the heat transfer plates 50a, 50b. The heat medium rises from the lower end of the second guide portion 70b to the second connecting holes 54a, 54b. In this way, because the distance from the first connecting holes 52a, 52b to the second connecting holes 54a, 54b can be sufficiently guaranteed, the reduction in heat exchange efficiency between the heat medium and the refrigerant can be suppressed. The distance the heat medium travels from the lower end of the second guide portion 70b to the second connecting holes 54a, 54b is relatively long. Therefore, the temperature difference between the heat medium at the lower end of the heat transfer plates 50a, 50b and the heat medium at the second connecting holes 54a, 54b can be sufficiently guaranteed. As a result, the temperature of the heat medium at the lower end of the heat transfer plates 50a, 50b is relatively high, thereby promoting heat exchange between the refrigerant and the heat medium in the lower part of the heat transfer plates 50a, 50b. Furthermore, a space is formed on the upper side of the plate bundle within the internal space 21 of the housing 20. In this space, incompletely vaporized liquid refrigerant falls onto the plate bundle 40. This suppresses the outflow of liquid refrigerant from the refrigerant outlet, thereby preventing liquid refrigerant from flowing outside the housing 20.

[0101] -Third variation example-

[0102] like Figure 8 As shown, in the third variation, the guide portion 70 is formed by an elongated plate member 75. The plate member 75 consists of a first plate portion 75a and a second plate portion 75b. The first plate portion 75a is disposed between the first connecting holes 52a, 52b and the second connecting holes 54a, 54b. The second plate portion 75b extends downward from both ends of the first plate portion 75a. The length L1 of the first plate portion 75a is approximately half the length from one end of the heat transfer plates 50a, 50b to the other end. The length L2 of the second plate portion 75b is approximately one-third the length L1 of the first plate portion 75a. The lower end of the second plate portion 75b is located at an intermediate height between the center O of the second connecting holes 54a, 54b and the lower end of the second connecting holes 54a, 54b.

[0103] - Fourth variation -

[0104] like Figure 9 As shown, the heat exchanger 10 in this embodiment may also include an eliminator 15. The eliminator 15 is a component for capturing droplets of liquid refrigerant flowing along with the gaseous refrigerant. The eliminator 15 is, for example, formed as a thick plate made of stacked metal mesh, through which the refrigerant can pass.

[0105] The droplet separator 15 is housed within the internal space 21 of the housing 20. The droplet separator 15 is positioned to traverse the internal space 21 of the housing 20, specifically on the upper side of the plate bundle 40. Gaseous refrigerant passing through the droplet separator 15 flows out of the housing 20 through the refrigerant outlet 33. Conversely, liquid refrigerant captured by the droplet separator 15 is converted into relatively large droplets and falls downwards.

[0106] - Fifth variation -

[0107] like Figure 10 As shown, when viewed from the front of the heat transfer plates 50a and 50b, the guide portion 70 can be formed in an inverted V shape. The apex of the guide portion 70 is formed between the lower end of the first connecting holes 52a and 52b and the upper end of the second connecting holes 54a and 54b. Alternatively, the guide portion 70 can also be formed in an inverted U shape, which is not shown.

[0108] -Sixth variation-

[0109] The first angle α1 of the first embossed pattern 62a and the second angle α2 of the second embossed pattern 62b can be the same angle. For example, the first angle α1 of the first embossed pattern 62a and the second angle α2 of the second embossed pattern 62b can both be 0 degrees, in other words, they can both be in the horizontal direction.

[0110] -Seventh Variation-

[0111] The heat exchanger 10 in this embodiment can also be a falling film plate heat exchanger. Strictly speaking, the heat exchanger 10 may have a sprayer for spraying liquid refrigerant onto the plate bundle 40 above the plate bundle 40 inside the housing 20. Furthermore, the heat exchanger 10 may also include a plate bundle with a configuration for spraying liquid refrigerant.

[0112] The embodiments and variations have been described above, but it should be understood that various changes can be made to the manner and specific details without departing from the spirit and scope of the claims. The embodiments and variations described above can also be appropriately combined and substituted, provided that the function of the object of this disclosure is not affected. The terms "first," "second," "third," etc., used above are only used to distinguish statements containing these terms and do not limit the number or order of the statements.

[0113] -Industry Applicability-

[0114] In summary, this disclosure is useful for plate heat exchangers.

[0115] - Symbol Explanation -

[0116] 20. Housing

[0117] 40 plate bundles

[0118] 41 Refrigerant Flow Path

[0119] 42. Heat medium flow path

[0120] 50a First plate (heat transfer plate)

[0121] 50b Second plate (heat transfer plate)

[0122] 52a First inlet hole (first connecting hole)

[0123] 54a First outlet hole (second connecting hole)

[0124] 52b Second inlet hole (first connecting hole)

[0125] 54b Second outlet hole (second connecting hole)

[0126] 70. Guiding section (Guiding section)

[0127] 75 plate components

[0128] 57a First rear side convex portion (convex portion)

[0129] 57b Second surface side protrusion (protrusion)

[0130] 56a First surface side concave portion (recessed portion)

[0131] 56b Second back side concave portion (recessed portion)

Claims

1. A plate-and-shell heat exchanger comprising a shell (20) and a plate bundle (40), the shell (20) forming an internal space (21), the plate bundle (40) having a plurality of heat transfer plates (50a, 50b) overlapping and joined to each other in a transverse direction and housed within the internal space (21) of the shell (20), the plate-and-shell heat exchanger causing refrigerant flowing into the internal space (21) of the shell (20) to evaporate, characterized in that: In the plate bundle (40), multiple refrigerant flow paths (41) and multiple heat medium flow paths (42) are formed adjacent to the heat transfer plates (50a, 50b). The refrigerant flow paths (41) are connected to the internal space (21) of the housing (20) and are used for refrigerant flow. The heat medium flow paths (42) are disconnected from the internal space (21) of the housing (20) and are used for heat medium flow. The heat transfer plates (50a, 50b) have a first connecting hole (52a, 52b) and a second connecting hole (54a, 54b). The first connecting holes (52a, 52b) are connected to the heat medium flow path (42) and introduce heat medium into the heat medium flow path (42). The second connecting holes (54a, 54b) are formed below the first connecting holes (52a, 52b) and communicate with the heat medium flow path (42), from which the heat medium is drawn out. In the heat medium flow path (42), a guide portion (70) is provided. The guide portion (70) is arranged to pass through the first connecting hole (52a, 52b) and the second connecting hole (54a, 54b), and guides the heat medium flowing into the heat medium flow path (42) from the first connecting hole (52a, 52b) to the side of the heat transfer plate (50a, 50b). The lower end of the guide portion (70) is located below the upper end of the second connecting hole (54a, 54b). The hot medium flowing in the hot medium flow path (42) cannot move downward under the guidance of the guide part (70). After flowing to the side of the heat transfer plate (50a, 50b), it bypasses the lower end of the guide part (70) and flows to the second connecting hole (54a, 54b).

2. The plate-and-shell heat exchanger according to claim 1, characterized in that: The distance between the lower end of the second connecting hole (54a, 54b) and the lower end of the heat transfer plate (50a, 50b) is greater than the distance between the upper end of the first connecting hole (52a, 52b) and the upper end of the heat transfer plate (50a, 50b).

3. The plate-and-shell heat exchanger according to claim 1 or 2, characterized in that: The center of the second connecting hole (54a, 54b) is at a higher height than the lower end of the guide (70).

4. The plate-and-shell heat exchanger according to claim 1 or 2, characterized in that: The guide portion (70) is a plate component (75) arranged in a manner that extends through a plurality of heat transfer plates (50a, 50b), which overlap and are joined together.

5. The plate-and-shell heat exchanger according to claim 3, characterized in that: The guide portion (70) is a plate component (75) arranged in a manner that extends through a plurality of heat transfer plates (50a, 50b), which overlap and are joined together.

6. The plate-and-shell heat exchanger according to claim 1 or 2, characterized in that: The guide portion (70) is composed of a protrusion (57a, 57b) or a recess (56a, 56b) formed on the heat transfer plate (50a, 50b).

7. The plate-and-shell heat exchanger according to claim 3, characterized in that: The guide portion (70) is composed of a protrusion (57a, 57b) or a recess (56a, 56b) formed on the heat transfer plate (50a, 50b).

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