Shell-and-plate type heat exchanger and refrigeration device

Abstract

A plate stack (30) is housed in an internal space (15) of a shell (11). A mesh member (50) is disposed above the plate stack (30) and below a refrigerant outlet (22). The mesh member (50) collects droplets contained in a refrigerant that has passed through refrigerant channels (31) and flowed out from an upper surface of the plate stack (30). A distance H [mm] from the upper surface of the plate stack (30) to a lower surface of the mesh member (50) satisfies a condition H ≥ 150.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a shell-and-plate heat exchanger and a refrigeration apparatus.BACKGROUND ART

[0002] Patent Document 1 discloses a shell-and-plate heat exchanger including a shell, a plate stack including a plurality of heat transfer plates and disposed in the shell, and a mesh member (eliminator).

[0003] A refrigerant in the shell flows into refrigerant channels of the plate stack, and exchanges heat with a heating medium flowing through heating medium channels of the plate stack and evaporates. The evaporated refrigerant flows out from an upper surface of the plate stack. The mesh member collects droplets contained in the refrigerant.CITATION LISTPATENT DOCUMENT

[0004] Patent Document 1: Japanese Unexamined Patent Publication No. 2021-110516SUMMARY OF THE INVENTIONTECHNICAL PROBLEM

[0005] However, if the flow velocity of the refrigerant that has flowed out from the upper surface of the plate stack is high, the droplets contained in the refrigerant may not be collected sufficiently by the mesh member and may pass through the mesh member and flow out of the shell through a refrigerant outlet.

[0006] An object of the present disclosure is to enable droplets contained in a refrigerant to be collected sufficiently by a mesh member.SOLUTION TO THE PROBLEM

[0007] A first aspect of the present disclosure includes: a shell (11) forming an internal space (15), the shell (11) having a refrigerant inlet (21) at a lower portion and a refrigerant outlet (22) at an upper portion; a plate stack (30) housed in the internal space (15), the plate stack (30) including a plurality of heat transfer plates (40) stacked in a plate thickness direction and joined together, the plate stack (30) having refrigerant channels (31) through which a refrigerant flows and heating medium channels (32) through which a heating medium flows; and a mesh member (50) disposed above the plate stack (30) and below the refrigerant outlet (22), the mesh member (50) being configured to collect droplets contained in the refrigerant that has passed through the refrigerant channels (31) and flowed out from an upper surface of the plate stack (30), wherein a distance H [mm] from the upper surface of the plate stack (30) to a lower surface of the mesh member (50) satisfies a condition H ≥ 150.

[0008] According to the first aspect, the distance from the plate stack (30) to the lower surface of the mesh member (50) is determined appropriately, thereby lowering the flow velocity of the refrigerant that has flowed out from the upper surface of the plate stack (30) before the refrigerant reaches the mesh member (50). Thus, the droplets are easily collected by the mesh member (50).

[0009] A second aspect of the present disclosure is an embodiment of the shell-and-plate heat exchanger of the first aspect. In the second aspect, a thickness t [mm] of the mesh member (50) in an up-and-down direction satisfies a condition t ≥ 40.

[0010] According to the second aspect, the thickness of the mesh member (50) in the up-and-down direction is determined appropriately. Thus, the droplets contained in the refrigerant passing through the mesh member (50) are easily collected.

[0011] A third aspect of the present disclosure is an embodiment of the shell-and-plate heat exchanger of the first or second aspect. In the third aspect, a total opening area S1 of the refrigerant channels (31) that are open to the upper surface of the plate stack (30) and an area S2 of the mesh member (50) when viewed in an up-and-down direction satisfy a condition 2 × S1 ≤ S2 ≤ 4 × S1.

[0012] According to the third aspect, the total opening area S1 of the refrigerant channels (31) and the area S2 of the mesh member (50) are determined appropriately. Thus, the refrigerant channels (31) of the plate stack (30) are sufficiently covered by the mesh member (50), and the droplets are easily collected by the mesh member (50).

[0013] A fourth aspect of the present disclosure is an embodiment of the shell-and-plate heat exchanger of any one of the first to third aspects. In the fourth aspect, a direction orthogonal to a stacking direction of the heat transfer plates (40) and an up-and-down direction is referred to as a width direction, and the shell-and-plate heat exchanger further includes a pair of supports (52) fixed to an inner surface of the shell (11), the supports (52) each having a recess (53) into which both end portions of the mesh member (50) in the width direction are fitted.

[0014] According to the fourth aspect, the mesh member (50) is inserted into the recesses (53) of the pair of supports (52). Thus, the mesh member (50) can be housed in, and supported by, the shell (11).

[0015] A fifth aspect of the present disclosure is an embodiment of the shell-and-plate heat exchanger of any one of the first to third aspects. In the fifth aspect, a direction orthogonal to a stacking direction of the heat transfer plates (40) and an up-and-down direction is referred to as a width direction, and the shell-and-plate heat exchanger further includes: a pair of lower surface plates (55) fixed to an inner surface of the shell (11) and supporting lower surface sides of both end portions of the mesh member (50) in the width direction; and a pair of upper surface plates (56) fixed to the inner surface of the shell (11) and disposed on upper surface sides of both end portions of the mesh member (50) in the width direction.

[0016] According to the fifth aspect, the mesh member (50) is inserted along the upper surface of the pair of lower surface plates (55), and the pair of upper surface plates (56) presses the upper surface sides of both end portions of the mesh member (50) in the width direction. Thus, the mesh member (50) can be housed in, and supported by, the shell (11).

[0017] A sixth aspect of the present disclosure is an embodiment of the shell-and-plate heat exchanger of any one of the first to fifth aspects. In the sixth aspect, the refrigerant is a single component refrigerant, which is an HFO refrigerant, or a refrigerant mixture containing the HFO refrigerant as a component.

[0018] According to the sixth aspect, a single component refrigerant, which is an HFO refrigerant, or a refrigerant mixture containing the HFO refrigerant as a component can be used as the refrigerant.

[0019] A seventh aspect of the present disclosure is directed to a refrigeration apparatus including: the shell-and-plate heat exchanger (10) of any one of the first to sixth aspects; and a refrigerant circuit (1a) through which a refrigerant that has exchanged heat in the shell-and-plate heat exchanger (10) flows.

[0020] According to the seventh aspect, it is possible to provide the refrigeration apparatus including the shell-and-plate heat exchanger (10) and the refrigerant circuit (1a).BRIEF DESCRIPTION OF THE DRAWINGS

[0021] [FIG. 1] FIG. 1 is a refrigerant circuit diagram illustrating a configuration of a refrigeration apparatus according to a first embodiment. [FIG. 2] FIG. 2 is a side cross-sectional view illustrating a configuration of a shell-and-plate heat exchanger. [FIG. 3] FIG. 3 is a front cross-sectional view illustrating the configuration of the shell-and-plate heat exchanger. [FIG. 4] FIG. 4 is a side cross-sectional view illustrating a configuration of a plate stack. [FIG. 5] FIG. 5 is a graph showing the relationship between the thickness of a mesh member and the average flow velocity. [FIG. 6] FIG. 6 is a graph showing the relationship between the distance from an upper surface of the plate stack to a lower surface of the mesh member and the critical flow velocity. [FIG. 7] FIG. 7 is a diagram for describing the relationship between the total opening area of refrigerant channels that are open to the upper surface of the plate stack and the area of the mesh member when viewed in an up-and-down direction. [FIG. 8] FIG. 8 is a front cross-sectional view illustrating a configuration of a shell-and-plate heat exchanger according to a second embodiment. DESCRIPTION OF EMBODIMENTS«First Embodiment»

[0022] As illustrated in FIG. 1, a shell-and-plate heat exchanger (10) (hereinafter simply referred to as a "heat exchanger") is provided in a refrigeration apparatus (1). The refrigeration apparatus (1) includes a refrigerant circuit (1a) filled with a refrigerant. The refrigerant circuit (1a) includes a compressor (2), a radiator (3), a decompression mechanism (4), and the heat exchanger (10) serving as an evaporator. The decompression mechanism (4) is, for example, an expansion valve. The refrigerant circuit (1a) performs a vapor compression refrigeration cycle.

[0023] The refrigeration apparatus (1) is an air conditioner, for example. The air conditioner may be any of a cooling-only apparatus, a heating-only apparatus, or an air conditioner switchable between cooling and heating. In this case, the air conditioner has a switching mechanism (e.g., a four-way switching valve) configured to switch the direction of circulation of the refrigerant. The refrigeration apparatus (1) may be a water heater, a chiller unit, or a cooling apparatus configured to cool air in an internal space. The cooling apparatus cools air in a refrigerator, a freezer, a container, or the like.<Heat Exchanger>

[0024] As illustrated in FIGS. 2 and 3, the heat exchanger (10) includes a shell (11) and a plate stack (30). The shell (11) has an internal space (15). The refrigerant flows into the internal space (15) of the shell (11). The plate stack (30) is housed in the internal space (15) of the shell (11). The refrigerant exchanges heat with a heating medium flowing in the plate stack (30). As can be seen, the heat exchanger (10) allows the refrigerant that has flowed into the internal space (15) of the shell (11) to evaporate, and thus, functions as an evaporator.

[0025] Here, the refrigerant used is a single component refrigerant, which is a hydrofluoroolefin (HFO) refrigerant, or a refrigerant mixture containing the HFO refrigerant as a component. Specifically, R1233zd(E), R1234ze(E), R513A, or any other suitable refrigerant is used. As the heating medium, water and brine are used, for example.<Shell>

[0026] The shell (11) includes a cylindrical body (12), support legs (13), and closing members (14). The cylindrical body (12) is a circular cylindrical member extending in a horizontal direction and having openings on both axial ends.

[0027] The support legs (13) are located on both axial end sides of the cylindrical body (12). Each of the support legs (13) has a hole corresponding to the opening of the cylindrical body (12). The support legs (13) are attached to the cylindrical body (12) by welding, for example.

[0028] The closing members (14) close the respective openings on both ends of the cylindrical body (12). The closing members (14) are fastened to the associated support legs (13) through clamping bolts, for example.

[0029] The shell (11) has the internal space (15) defined by the cylindrical body (12), the support legs (13), and the closing members (14). The shell (11) is arranged so that its axial direction coincides with the horizontal direction. The internal space (15) stores the liquid refrigerant. The plate stack (30) is housed in the internal space (15).

[0030] The shell (11) has a refrigerant inlet (21) and a refrigerant outlet (22). The refrigerant inlet (21) is formed at a lower portion of the shell (11). The refrigerant inlet (21) is formed at the bottom of the shell (11). The refrigerant is introduced into the internal space (15) through the refrigerant inlet (21). In the example shown in FIG. 2, the refrigerant inlet (21) is formed in a lower portion of the shell (11) at a central position in the stacking direction of the plate stack (30).

[0031] The refrigerant outlet (22) is formed at an upper portion of the shell (11). The refrigerant evaporated in the internal space (15) is emitted to the outside of the shell (11) through the refrigerant outlet (22). The refrigerant inlet (21) and the refrigerant outlet (22) are connected to the refrigerant circuit (1a).

[0032] The shell (11) has a heating medium inlet (23) and a heating medium outlet (24). The heating medium inlet (23) and the heating medium outlet (24) are tubular members.

[0033] The heating medium inlet (23) penetrates one axial end of the shell (11). The heating medium inlet (23) is connected to a heating medium introduction path (33) of the plate stack (30). The heating medium inlet (23) supplies the heating medium to the plate stack (30). The refrigerant that has flowed into the internal space (15) of the shell (11) exchanges heat with the heating medium that has flowed into heating medium channels (32), which will be described later, of the plate stack (30).

[0034] The heating medium outlet (24) penetrates the one axial end of the shell (11) above the heating medium inlet (23). The heating medium outlet (24) is connected to a heating medium emission path (34) of the plate stack (30). The heating medium outlet (24) emits the heating medium from the plate stack (30). The heating medium inlet (23) may be located above the heating medium outlet (24).

[0035] A partitioning member (60) is located below the plate stack (30). The partitioning member (60) includes a partition plate (61). The partition plate (61) serves as a partition between the plate stack (30) and the refrigerant inlet (21). The partition plate (61) extends in the stacking direction of the plate stack (30) along a lower surface of the plate stack (30).

[0036] The partition plate (61) has a plurality of communication holes (65). The refrigerant that has flowed in through the refrigerant inlet (21) flows along the partition plate (61) in the stacking direction of heat transfer plates (40), and is discharged from the plurality of communication holes (65) toward the plate stack (30).

[0037] A mesh member (50) is located above the plate stack (30) and below the refrigerant outlet (22). The refrigerant passes through the refrigerant channels (31) of the plate stack (30), and then flows out from an upper surface of the plate stack (30) toward the mesh member (50). The mesh member (50) collects droplets contained in the refrigerant that has passed through the refrigerant channels (31) and flowed out from the upper surface of the plate stack (30). The mesh member (50) is in a thick plate shape made of a stack of metal meshes, for example. The refrigerant can pass through the mesh member (50) in the thickness direction. The refrigerant that has passed through the mesh member (50) flows out from the refrigerant outlet (22).

[0038] The void coefficient, which is an index indicating the fineness of meshes of the mesh member (50), is, for example, 95% or more and 99% or less. The density of the mesh member (50) is 50 kg / m 3< or more and 400 kg / m 3< or less, for example.

[0039] As illustrated in FIG. 3, the mesh member (50) is supported by a pair of supports (52). Specifically, in the following description, a direction orthogonal to the stacking direction of the heat transfer plates (40) and the up-and-down direction is referred to as the width direction. The inner surface of the shell (11) is provided with a pair of fixing parts (51) extending in the axial direction. The pair of fixing parts (51) are spaced apart from each other in the width direction.

[0040] The supports (52) are fixed to the inner surface of the shell (11) with the fixing parts (51) interposed therebetween. The supports (52) each have a recess (53) that opens toward the mesh member (50). The recess (53) extends along the axial direction of the shell (11). Both end portions of the mesh member (50) in the width direction are inserted into the respective recesses (53) of the pair of supports (52). Thus, the mesh member (50) is housed in, and supported by, the shell (11).<Plate Stack>

[0041] The plate stack (30) includes a plurality of heat transfer plates (40) stacked and joined together in a plate thickness direction. The plate stack (30) is housed in the internal space (15) of the shell (11) so that the stacking direction of the heat transfer plates (40) coincides with the horizontal direction. The plate stack (30) has a length of, for example, 600 mm to 1500 mm in its width direction.

[0042] As illustrated in FIG. 4, the heat transfer plates (40) include first plates (40a) and second plates (40b). The first plates (40a) and the second plates (40b) are alternately stacked to form the plate stack (30). The second plates (40b) correspond to the first plates (40a) turned back to front.

[0043] In the following description, for each of the first plates (40a) and the second plates (40b), a surface on the left side in FIG. 4 will be referred to as a "front surface," and a surface on the right side in FIGS. 4 will be referred to as a "back surface."<Heating Medium Introduction Path and Heating Medium Emission Path>

[0044] Each of the first plates (40a) has an inlet protrusion (41a) and an outlet protrusion (43a). The inlet protrusion (41a) and the outlet protrusion (43a) are portions of the first plate (40a) bulged toward the front surface.

[0045] The inlet protrusion (41a) is formed in a lower portion of the first plate (40a). A first inlet hole (42a) is formed in a center portion of the inlet protrusion (41a). The first inlet hole (42a) is a circular hole penetrating the first plate (40a) in the thickness direction.

[0046] The outlet protrusion (43a) is formed in an upper portion of the first plate (40a). A first outlet hole (44a) is formed in a center portion of the outlet protrusion (43a). The first outlet hole (44a) is a circular hole penetrating the first plate (40a) in the thickness direction.

[0047] Each of the second plates (40b) has an inlet recess (41b) and an outlet recess (43b). The inlet recess (41b) and the outlet recess (43b) are portions of the second plate (40b) bulged toward the back surface.

[0048] The inlet recess (41b) is formed in a lower portion of the second plate (40b). A second inlet hole (42b) is formed in a center portion of the inlet recess (41b). The second inlet hole (42b) is a circular hole penetrating the second plate (40b) in the thickness direction. The inlet recess (41b) is formed at a position corresponding to the inlet protrusion (41a) of the first plate (40a). The second inlet hole (42b) is formed at a position corresponding to the first inlet hole (42a) of the first plate (40a).

[0049] The outlet recess (43b) is formed in an upper portion of the second plate (40b). A second outlet hole (44b) is formed in a center portion of the outlet recess (43b). The second outlet hole (44b) is a circular hole penetrating the second plate (40b) in the thickness direction. The outlet recess (43b) is formed at a position corresponding to the outlet protrusion (43a) of the first plate (40a). The second outlet hole (44b) is formed at a position corresponding to the first outlet hole (44a) of the first plate (40a).

[0050] In the plate stack (30), each first plate (40a) and an adjacent one of the second plates (40b) on the back surface side of the first plate (40a) are welded together at their peripheral portions along the entire perimeter. These plates may be brazed together.

[0051] In the plate stack (30), the first inlet hole (42a) of each first plate (40a) overlaps the second inlet hole (42b) of an adjacent one of the second plates (40b) on the front surface side of the first plate (40a). The rims of the overlapping first inlet hole (42a) and second inlet hole (42b) are welded together along the entire perimeter. These rims may be brazed together. The first inlet hole (42a) and the second inlet hole (42b) communicate with the heating medium channels (32), which will be described later, to introduce the heating medium into the heating medium channels (32).

[0052] In the plate stack (30), the first outlet hole (44a) of each first plate (40a) overlaps the second outlet hole (44b) of an adjacent one of the second plates (40b) on the front surface side of the first plate (40a). The rims of the overlapping first outlet hole (44a) and second outlet hole (44b) are welded together along the entire perimeter. These rims may be brazed together. The first outlet hole (44a) and the second outlet hole (44b) communicate with the heating medium channels (32), which will be described later, to emit the heating medium from the heating medium channels (32).

[0053] In the plate stack (30), the inlet protrusions (41a) and first inlet holes (42a) of the first plates (40a) and the inlet recesses (41b) and second inlet holes (42b) of the second plates (40b) form the heating medium introduction path (33).

[0054] In the plate stack (30), the outlet protrusions (43a) and first outlet holes (44a) of the first plates (40a) and the outlet recesses (43b) and second outlet holes (44b) of the second plates (40b) form the heating medium emission path (34).

[0055] The heating medium introduction path (33) is a passage extending in the stacking direction of the heat transfer plates (40) in the plate stack (30). The heating medium introduction path (33) is a passage isolated from the internal space (15) of the shell (11), and allows all the heating medium channels (32) to communicate with the heating medium inlet (23).

[0056] The heating medium emission path (34) is a passage extending in the stacking direction of the heat transfer plates (40) in the plate stack (30). The heating medium emission path (34) is a passage isolated from the internal space (15) of the shell (11), and allows all the heating medium channels (32) to communicate with the heating medium outlet (24).<Refrigerant Channel and Heating Medium Channel>

[0057] The plate stack (30) includes a refrigerant channel (31) and a heating medium channel (32). Multiple refrigerant channels (31) and multiple heating medium channels (32) are formed with the heat transfer plate (40) interposed therebetween. The heat transfer plate (40) separates the refrigerant channel (31) and the heating medium channel (32) from each other. Each of the first plate (40a) and the second plate (40b) includes repetition of long and narrow ridges and grooves.

[0058] Each first plate (40a) includes first front-side protrusions (45a) and first back-side protrusions (47a) alternately arranged. The first front-side protrusions (45a) bulge toward the front side of the first plate (40a). The first back-side protrusions (47a) bulge toward the back side of the first plate (40a).

[0059] Each second plate (40b) includes second front-side protrusions (47b) and second back-side protrusions (45b) alternately arranged. The second front-side protrusions (47b) bulge toward the front side of the second plate (40b). The second back-side protrusions (45b) bulge toward the back side of the second plate (40b).

[0060] Each of the refrigerant channels (31) is a channel sandwiched between the front surface of the first plate (40a) and the back surface of the second plate (40b). The refrigerant channel (31) is a channel that communicates with the internal space (15) of the shell (11) and allows the refrigerant to flow therethrough. Specifically, the refrigerant channels (31) include channels each formed between the front surface of the first back-side protrusion (47a) and the back surface of the second front-side protrusion (47b).

[0061] Each of the heating medium channels (32) is a channel sandwiched between the back surface of the first plate (40a) and the front surface of the second plate (40b). The heating medium channel (32) is a channel isolated from the internal space (15) of the shell (11) and allows the heating medium to flow therethrough. Specifically, the heating medium channels (32) include channels each formed between the back surface of the first front-side protrusion (45a) and the front surface of the second back-side protrusion (45b).<Flows of Heating Medium and Refrigerant>

[0062] Flows of the heating medium and the refrigerant in the heat exchanger (10) will be described. As illustrated in FIG. 4, the heating medium flows from the heating medium inlet (23) into the heating medium introduction path (33). The heating medium flowing through the heating medium introduction path (33) flows through the heating medium channels (32) from the first inlet holes (42a) and the second inlet holes (42b) toward the first outlet holes (44a) and the second outlet holes (44b).

[0063] Specifically, the heating medium flowing through the heating medium introduction path (33) enters the heating medium channel (32). The heating medium flows along the heating medium channel (32), and enters an adjacent heating medium channel (32) above the heating medium channel (32). In this manner, the heating medium flows upward while flowing from one end to the other of the heat transfer plate (40).

[0064] Next, the flow of the refrigerant will be described below. The refrigerant that has passed through the decompression mechanism (4) in the refrigerant circuit (1a) flows into the heat exchanger (10). The refrigerant flows into the internal space (15) of the shell (11) through the refrigerant inlet (21).

[0065] In the internal space (15) of the shell (11), a large portion of the plate stack (30) is immersed in the liquid refrigerant, and the liquid refrigerant flows into the refrigerant channels (31) of the plate stack (30). The liquid refrigerant that has flowed into the refrigerant channels (31) is in contact with the heat transfer plates (40), and absorbs heat from the heating medium flowing through the heating medium channels (32) and evaporates. The gas refrigerant generated in the refrigerant channels (31) flows upward to flow out of the refrigerant channels (31) and is blown upward from the upper surface of the plate stack (30).

[0066] The gas refrigerant that has passed through the plate stack (30) passes through the mesh member (50). The mesh member (50) collects the liquid refrigerant contained in the gas refrigerant. The gas refrigerant that has passed through the mesh member (50) flows out of the shell (11) through the refrigerant outlet (22).<Arrangement of Mesh Member>

[0067] If the flow velocity of the refrigerant that has flowed out from the upper surface of the plate stack (30) is high, the droplets contained in the refrigerant may not be collected sufficiently by the mesh member (50) and may pass through the mesh member (50) and flow out of the shell (11) through the refrigerant outlet (22). In particular, if a single component refrigerant, which is an HFO refrigerant, or a refrigerant mixture containing the HFO refrigerant as a component is used as the refrigerant, the density of the refrigerant is relatively low; therefore, the flow velocity tends to increase.

[0068] To address this, in the present embodiment, the mesh member (50) is configured to sufficiently collect droplets contained in the refrigerant.

[0069] In the following description, the distance from the upper surface of the plate stack (30) to the lower surface of the mesh member (50) is referred to as H [mm], and the thickness of the mesh member (50) in the up-and-down direction is referred to as t [mm].

[0070] FIG. 5 is a graph showing the relationship between the thickness of the mesh member (50) and the average flow velocity. As shown in FIG. 5, as the thickness t of the mesh member (50) increases, the average flow velocity of the refrigerant tends to increase. In the example shown in FIG. 5, when t = 40, the average flow velocity is 1.9 m / s. In this embodiment, the mesh member (50) that satisfies the condition t ≥ 40 is used.

[0071] FIG. 6 is a graph showing the relationship between the distance from the upper surface of the plate stack (30) to the lower surface of the mesh member (50) and the critical flow velocity. The critical flow velocity as used herein indicates the limit of the average flow velocity at which droplets can be collected from the refrigerant. That is, when the average flow velocity of the refrigerant passing through the mesh member (50) is higher than the critical flow velocity, the mesh member (50) cannot collect droplets sufficiently, resulting in the scattering of the droplets.

[0072] The square-shaped plots in FIG. 6 indicate the critical flow velocities obtained from a standalone test of the mesh member (50). As shown in FIG. 6, as the distance H increases, the critical flow velocity increases, and the critical flow velocity tends to remain around 2.0 m / s.

[0073] In this embodiment, the mesh member (50) is positioned to satisfy the condition H ≥ 150. With this configuration, scattering of droplets contained in the refrigerant can be reduced as long as the average flow velocity of the refrigerant is up to 2.0 m / s.

[0074] Conditions for covering the refrigerant channels (31) of the plate stack (30) sufficiently with the mesh member (50) have also been studied. FIG. 7 is a schematic view of the plate stack (30) and the mesh member (50) when viewed in the up-and-down direction. When viewed from above, the mesh member (50) and the plate stack (30) overlap each other. Specifically, the mesh member (50) and the openings of the refrigerant channels (31) on the upper surface of the plate stack (30) overlap. In FIG. 7, the portion of the mesh member (50) that overlaps the plate stack (30) is schematically illustrated. Here, it is preferable that the area of the mesh member (50) is set to satisfy the condition 2 × S1 ≤ S2 ≤ 4 × S1, where S1 represents the total opening area of the refrigerant channels (31) that are open on the upper surface of the plate stack (30), and S2 represents the area of the mesh member (50) when viewed in the up-and-down direction.

[0075] In FIG. 7, the refrigerant channels (31) are schematically illustrated by rectangles for ease of understanding of the description, but the shape and size of the refrigerant channels (31) differ from those in the actual configuration, and are not limited to those of this embodiment.-Advantages of First Embodiment-

[0076] According to this embodiment, the distance from the plate stack (30) to the lower surface of the mesh member (50) is determined appropriately, thereby lowering the flow velocity of the refrigerant that has flowed out from the upper surface of the plate stack (30) before the refrigerant reaches the mesh member (50). Thus, the droplets are easily collected by the mesh member (50).

[0077] According to this embodiment, the thickness of the mesh member (50) in the up-and-down direction is determined appropriately. Thus, the droplets contained in the refrigerant passing through the mesh member (50) are easily collected.

[0078] According to this embodiment, the total opening area S1 of the refrigerant channels (31) and the area S2 of the mesh member (50) are determined appropriately. Thus, the refrigerant channels (31) of the plate stack (30) are sufficiently covered by the mesh member (50), and the droplets are easily collected by the mesh member (50).

[0079] According to this embodiment, the mesh member (50) is inserted into the recesses (53) of the pair of supports (52). Thus, the mesh member (50) can be housed in, and supported by, the shell (11).

[0080] According to this embodiment, a single component refrigerant, which is an HFO refrigerant, or a refrigerant mixture containing the HFO refrigerant as a component can be used as the refrigerant.

[0081] According to this embodiment, it is possible to provide the refrigeration apparatus (1) including the shell-and-plate heat exchanger (10) and the refrigerant circuit (1a).«Second Embodiment»

[0082] In the following description, the same reference characters designate the same components as those of the first embodiment, and the description is focused only on the differences.

[0083] As illustrated in FIG. 8, the inner surface of the shell (11) is provided with a pair of fixing parts (51) extending in the axial direction. The pair of fixing parts (51) are spaced apart from each other in the width direction.

[0084] The mesh member (50) is supported by a pair of lower surface plates (55). The lower surface plates (55) are fixed to the inner surface of the shell (11) with the fixing parts (51) interposed therebetween. The mesh member (50) is inserted into the shell (11) along the upper surfaces of the pair of lower surface plates (55), and is placed on the lower surface plates (55).

[0085] A pair of upper surface plates (56) are arranged on the upper surface sides of both end portions of the mesh member (50) in the width direction. The upper surface plates (56) are fixed to the inner surface of the shell (11) with the fixing parts (51) interposed therebetween. The upper surface plates (56) press the upper surface sides of both end portions of the mesh member (50) in the width direction down. The mesh member (50) is sandwiched between the lower surface plates (55) and the upper surface plates (56). Thus, the mesh member (50) is housed in, and supported by, the shell (11).-Advantages of Second Embodiment-

[0086] According to this embodiment, the mesh member (50) is inserted along the upper surface of the pair of lower surface plates (55), and the pair of upper surface plates (56) presses the upper surface sides of both end portions of the mesh member (50) in the width direction. Thus, the mesh member (50) can be housed in, and supported by, the shell (11).«Other Embodiments»

[0087] It will be understood that the embodiments and variations described above can be modified with various changes in form and details without departing from the spirit and scope of the claims. The elements according to embodiments, the variations thereof, and the other embodiments may be combined and replaced with each other. In addition, the expressions of "first," "second," "third," ... , in the specification and claims are used to distinguish the terms to which these expressions are given, and do not limit the number and order of the terms.INDUSTRIAL APPLICABILITY

[0088] As can be seen from the foregoing description, the present disclosure is useful for a shell-and-plate heat exchanger and a refrigeration apparatus.DESCRIPTION OF REFERENCE CHARACTERS

[0089] 1Refrigeration Apparatus 1aRefrigerant Circuit 10Shell-and-Plate Heat Exchanger 11Shell 15Internal Space 21Refrigerant Inlet 22Refrigerant Outlet 30Plate Stack 31Refrigerant Channel 32Heating Medium Channel 40Heat Transfer Plate 50Mesh Member 52Support 53Recess 55Lower Surface Plate 56Upper Surface Plate

Claims

1. A shell-and-plate heat exchanger comprising: a shell (11) forming an internal space (15), the shell (11) having a refrigerant inlet (21) at a lower portion and a refrigerant outlet (22) at an upper portion; a plate stack (30) housed in the internal space (15), the plate stack (30) including a plurality of heat transfer plates (40) stacked in a plate thickness direction and joined together, the plate stack (30) having refrigerant channels (31) through which a refrigerant flows and heating medium channels (32) through which a heating medium flows; and a mesh member (50) disposed above the plate stack (30) and below the refrigerant outlet (22), the mesh member (50) being configured to collect droplets contained in the refrigerant that has passed through the refrigerant channels (31) and flowed out from an upper surface of the plate stack (30), wherein a distance H [mm] from the upper surface of the plate stack (30) to a lower surface of the mesh member (50) satisfies a condition H ≥ 150.

2. The shell-and-plate heat exchanger of claim 1, wherein a thickness t [mm] of the mesh member (50) in an up-and-down direction satisfies a condition t ≥ 40.

3. The shell-and-plate heat exchanger of claim 1 or 2, wherein a total opening area S1 of the refrigerant channels (31) that are open to the upper surface of the plate stack (30) and an area S2 of the mesh member (50) when viewed in an up-and-down direction satisfy a condition 2 × S1 ≤ S2 ≤ 4 × S1.

4. The shell-and-plate heat exchanger of any one of claims 1 to 3, wherein a direction orthogonal to a stacking direction of the heat transfer plates (40) and an up-and-down direction is referred to as a width direction, and the shell-and-plate heat exchanger further includes a pair of supports (52) fixed to an inner surface of the shell (11), the supports (52) each having a recess (53) into which both end portions of the mesh member (50) in the width direction are fitted.

5. The shell-and-plate heat exchanger of any one of claims 1 to 3, wherein a direction orthogonal to a stacking direction of the heat transfer plates (40) and an up-and-down direction is referred to as a width direction, and the shell-and-plate heat exchanger further includes: a pair of lower surface plates (55) fixed to an inner surface of the shell (11) and supporting lower surface sides of both end portions of the mesh member (50) in the width direction; and a pair of upper surface plates (56) fixed to the inner surface of the shell (11) and disposed on upper surface sides of both end portions of the mesh member (50) in the width direction.

6. The shell-and-plate heat exchanger of any one of claims 1 to 5, wherein the refrigerant is a single component refrigerant, which is an HFO refrigerant, or a refrigerant mixture containing the HFO refrigerant as a component.

7. A refrigeration apparatus comprising: the shell-and-plate heat exchanger (10) of any one of claims 1 to 6; and a refrigerant circuit (1a) through which a refrigerant having exchanged heat in the shell-and-plate heat exchanger (10) flows.

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