Plate heat exchanger and unit

Abstract

The invention provides a plate heat exchanger and a unit. The plate heat exchanger comprises a first end plate, a first plate sheet group, a second plate sheet group and a second end plate which are stacked in the first direction; a first refrigerant channel and a first secondary refrigerant channel which are isolated from each other are formed between adjacent first heat exchange plates in the first plate set, a second refrigerant channel and a second secondary refrigerant channel which are isolated from each other are formed between adjacent second heat exchange plates in the second plate set, and the second secondary refrigerant channel communicates with the first secondary refrigerant channel. The first refrigerant channel and the second refrigerant channel are isolated from each other, a first refrigerant inlet and outlet is formed in the first end plate, and a second refrigerant inlet and outlet and a secondary refrigerant inlet and outlet are formed in the second end plate. According to the plate heat exchanger, a single heat exchange plate is only provided with four corner holes, heat exchange of three different media can be achieved at the same time, the production process is simplified, the length of the refrigerant inlet header can be reduced, and the problem that fluid distribution between refrigerant plates is not uniform is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of plate heat exchangers, and in particular to a plate heat exchanger and a unit. Background Art

[0002] A plate heat exchanger is a highly efficient heat exchanger composed of stacked corrugated heat exchange plates. Multiple fluid channels are formed between the plates, allowing two fluids (such as liquid to liquid or liquid to steam) to circulate between them. Heat is exchanged through the plates, achieving heating or cooling. Currently, it is widely used in industries such as refrigeration, heat pump systems, heat treatment, petrochemicals, energy, and waste heat recovery.

[0003] Two working media with different physical properties usually flow alternately inside a heat exchanger. However, for large systems such as modular air-cooled chillers (hot water units), they are equipped with two refrigerant circulation systems and one water system, and the three media exchange heat simultaneously. The current conventional technical solution is to design 6 corner holes on the top and bottom of the heat exchange plate. The middle corner hole serves as the inlet and outlet channels for water, and the corner holes on both sides serve as the inlet and outlet channels for the refrigerant medium. The two types of plates are stacked alternately and the refrigerant medium channels on both sides are sealed alternately to achieve heat exchange. This solution is complicated to assemble. If one accessory is assembled incorrectly, the entire sample will be scrapped.

[0004] For example, a dual-system plate heat exchanger consists of upper and lower end plates and several heat exchange plate groups. Each heat exchange plate group requires four different plate bodies, each with six through-holes, different distribution holes, and half-height surfaces. This requires four different sets of molds to process the plates, significantly increasing processing costs and assembly difficulty. Furthermore, this structure results in a long refrigerant inlet header, leading to uneven refrigerant distribution between the plates and reduced heat exchanger capacity. Summary of the Invention

[0005] The first purpose of the present invention is to provide a plate heat exchanger in which a single heat exchange plate has only four corner holes, which can realize heat exchange of three different media at the same time. Compared with the existing heat exchange plate structure with six corner holes, it reduces the assembly difficulty, simplifies the production process, effectively reduces the processing cost, improves production reliability, and at the same time can reduce the length of the refrigerant inlet manifold, thereby solving the problem of uneven fluid distribution between the refrigerant plates.

[0006] The second object of the present invention is to provide another plate heat exchanger that can be adapted to a single refrigerant system, has a simple structure, and can use the same set of plate molds as the above-mentioned dual refrigerant system, thereby reducing production costs and improving processing efficiency.

[0007] The third object of the present invention is to provide a unit using the above-mentioned plate heat exchanger.

[0008] To achieve the above-mentioned first purpose, the present invention provides a plate heat exchanger, comprising a first end plate, a first plate group, a second plate group and a second end plate stacked in sequence along a first direction; the first plate group comprises a plurality of first heat exchange plates stacked in sequence along the first direction, and a first refrigerant channel and a first coolant channel are formed between adjacent first heat exchange plates, which are fluidly isolated from each other; the second plate group comprises a plurality of second heat exchange plates stacked in sequence along the first direction, and a second refrigerant channel and a second coolant channel are formed between adjacent second heat exchange plates, which are fluidly isolated from each other, the second coolant channel is connected to the first coolant channel, and the first refrigerant channel and the second refrigerant channel are fluidly isolated from each other; a first refrigerant inlet and a first refrigerant outlet, both of which are connected to the first refrigerant channel, are provided on the first end plate; a second refrigerant inlet, a second refrigerant outlet, a coolant inlet and a coolant outlet are provided on the second end plate, the second refrigerant inlet and the second refrigerant outlet are both connected to the second refrigerant channel, and the coolant inlet and the coolant outlet are both connected to the second coolant channel.

[0009] As can be seen from the above scheme, this plate heat exchanger can be applied to dual refrigerant systems. A single heat exchange plate in this plate heat exchanger has only four corner holes, which can achieve heat exchange between three different media at the same time. Compared with the existing heat exchange plate structure with six corner holes, this reduces the difficulty of assembly, simplifies the production process, effectively reduces processing costs, and improves production reliability. At the same time, there is no need to adjust the heat exchange plate structure, and it can be converted into a plate heat exchanger for a single refrigeration system, reducing mold opening costs. In addition, compared with existing plate heat exchangers, the length of the refrigerant inlet and outlet headers are both reduced, thereby reducing the problem of uneven fluid distribution between the refrigerant plates.

[0010] A preferred solution is that the first plate group is provided with a first refrigerant inlet header, a first refrigerant outlet header, a first secondary refrigerant inlet header and a first secondary refrigerant outlet header, and the second plate group is provided with a second refrigerant inlet header, a second refrigerant outlet header, a second secondary refrigerant inlet header and a second secondary refrigerant outlet header; the first refrigerant inlet header and the first refrigerant outlet header are both connected to the first refrigerant channel, and the second refrigerant inlet header and the second refrigerant outlet header are both connected to the second refrigerant channel. The first refrigerant inlet header, the first refrigerant outlet header, the second refrigerant inlet header and the second refrigerant outlet header are all connected to the first refrigerant channel; the first refrigerant inlet header is opposite to and connected to the first refrigerant inlet, and the first refrigerant outlet header is opposite to and connected to the first refrigerant outlet; the second refrigerant inlet header is opposite to and connected to the second refrigerant inlet, and the second refrigerant outlet header is opposite to and connected to the second refrigerant outlet, the first refrigerant inlet header and the second refrigerant inlet header are both opposite to and connected to the refrigerant inlet, and the first refrigerant outlet header and the second refrigerant outlet header are both opposite to and connected to the refrigerant outlet.

[0011] A preferred solution is that no through holes are provided on the first plane of the two first heat exchange plates arranged near the second plate group in the first plate group, the first planes of the two first heat exchange plates are in contact with each other, and the first plane is arranged opposite to the first refrigerant inlet; and / or no through holes are provided on the second plane of the two second heat exchange plates arranged near the first plate group in the second plate group, the second planes of the two second heat exchange plates are in contact with each other, and the second plane is arranged opposite to the second refrigerant inlet.

[0012] It can be seen that no through holes are provided on the first plane and the second plane, thereby achieving mutual fluid isolation between the first refrigerant channel and the second refrigerant channel, and improving the pressure bearing capacity to avoid deformation of the heat exchange plate caused by excessive pressure at this location.

[0013] A preferred solution is that a first gasket is provided between the first plate group and the second plate group, and the first gasket is arranged opposite to the first refrigerant inlet in the first direction; and / or a second gasket is provided between the first plate group and the second plate group, and the second gasket is arranged opposite to the first refrigerant outlet in the first direction.

[0014] A further solution is that the first refrigerant inlet header and the second refrigerant inlet header are fluidically isolated by a first gasket; and / or the first refrigerant outlet header and the second refrigerant outlet header are fluidically isolated by a second gasket.

[0015] Thus, the spacer not only separates the flow channels but also provides stable support. At the same time, the position of the spacer can be adjusted to reasonably allocate the number of channels between the two systems according to the flow rate.

[0016] A further solution is that the first refrigerant inlet and the second refrigerant inlet are arranged opposite to each other in the first direction, and the first refrigerant outlet and the second refrigerant outlet are arranged opposite to each other in the first direction.

[0017] It can be seen that in this way, the first plate group and the second plate group can use the same set of heat exchange plates, thereby reducing costs.

[0018] A preferred solution is that the size of the first refrigerant inlet is equal to the size of the second refrigerant inlet; and / or the sizes of the first refrigerant outlet, the second refrigerant outlet, the coolant inlet and the coolant outlet are all larger than the size of the first refrigerant inlet; and / or the sizes of the first refrigerant outlet, the second refrigerant outlet, the coolant inlet and the coolant outlet are all larger than the size of the second refrigerant inlet.

[0019] It can be seen that the size of the refrigerant inlet is smaller than that of the other corner holes to avoid the problem of uneven flow distribution between channels caused by a sudden expansion of the cross section causing a decrease in flow velocity.

[0020] A preferred solution is that the sizes of the first refrigerant inlet, the second refrigerant inlet, the first refrigerant outlet and the second refrigerant outlet are equal, and the sizes of the secondary refrigerant inlet and the secondary refrigerant outlet are equal.

[0021] As can be seen, the four corner holes of the heat exchange plates of this structure are equal in size and arranged symmetrically. Of the two adjacent heat exchange plates, one heat exchange plate is placed normally, and the other heat exchange plate is rotated 180 degrees and stacked, forming a channel between the two. Therefore, only one type of heat exchange plate structure is required. Since the heat exchange plates only require one set of molds for processing, processing costs can be reduced. In addition, because the channel is formed by stacking two heat exchange plates of the same structure, the volume of the channels on both sides of the heat exchange plate is equal, forming a symmetrical structure suitable for working conditions with a small difference in the flow rate of hot and cold fluids.

[0022] A preferred solution is that the plate heat exchanger also includes a first reinforcing plate, which is arranged on the outer surface of the second end plate, and a first corner hole and a second corner hole are provided on the first reinforcing plate, the first corner hole is coaxially arranged with the second refrigerant inlet, and the second corner hole is coaxially arranged with the coolant outlet; and / or the plate heat exchanger also includes a second reinforcing plate, which is arranged on the outer surface of the second end plate, and a third corner hole and a fourth corner hole are provided on the second reinforcing plate, the third corner hole is coaxially arranged with the second refrigerant outlet, and the fourth corner hole is coaxially arranged with the coolant inlet.

[0023] It can be seen that the reinforcing plate is used to improve the pressure resistance of the plate heat exchanger.

[0024] A preferred solution is that a first flange plane is provided on the first heat exchange plate, the first flange plane is set at an angle to the plate body of the first heat exchange plate, a first anti-foolproof notch is opened on the first flange plane, and the first anti-foolproof notch is set close to one of the corners of the first heat exchange plate; and / or a second flange plane is provided on the second heat exchange plate, the second flange plane is set at an angle to the plate body of the second heat exchange plate, a second anti-foolproof notch is opened on the second flange plane, and the second anti-foolproof notch is set close to one of the corners of the second heat exchange plate.

[0025] It can be seen that by opening an anti-mistake notch on the flange surface, the type of plate and the installation direction can be identified during the assembly process.

[0026] A further solution is that a first sealing plane is further provided on the side of the first heat exchange plate where the first refrigerant channel is formed, the first sealing plane is perpendicular to the first direction and connected to the first flange plane, and the first sealing plane is arranged at at least one of the four corners of the first heat exchange plate; and / or a second sealing plane is further provided on the side of the second heat exchange plate where the second refrigerant channel is formed, the second sealing plane is perpendicular to the first direction and connected to the second flange plane, and the second sealing plane is arranged at at least one of the four corners of the second heat exchange plate.

[0027] It can be seen that after assembly and welding, on the coolant channel side, the sealing surfaces of the two adjacent heat exchange plates fit together to form a sealing surface, avoiding the risk of water accumulation and freezing cracking.

[0028] A further solution is that the first sealing plane is in the form of a minor arc, the arc edge of the first sealing plane is connected to the first flange plane, and the straight edge of the first sealing plane is connected to the heat exchange element of the first heat exchange plate; and / or the second sealing plane is in the form of a minor arc, the arc edge of the second sealing plane is connected to the second flange plane, and the straight edge of the second sealing plane is connected to the heat exchange element of the second heat exchange plate.

[0029] To achieve the above-mentioned second purpose, the present invention provides another plate heat exchanger, comprising a first end plate, a second plate group, and a second end plate stacked in sequence along a first direction; the second plate group comprises a plurality of second heat exchange plates stacked in sequence along the first direction, and a second refrigerant channel and a second coolant channel are formed between adjacent second heat exchange plates, which are fluidically isolated from each other; a first refrigerant inlet and a first refrigerant outlet are provided on the first end plate; a second refrigerant inlet, a second refrigerant outlet, a coolant inlet, and a coolant outlet are provided on the second end plate, and the second refrigerant inlet and the second refrigerant outlet are both connected to the second refrigerant channel , the refrigerant inlet and the refrigerant outlet are both connected to the second refrigerant channel; no through holes are provided on the second plane and the third plane of the two second heat exchange plates arranged near the first end plate in the second plate group, the second planes of the two second heat exchange plates are in contact with each other, the second plane is arranged opposite to the second refrigerant inlet and covers the first refrigerant inlet, the third planes of the two second heat exchange plates are in contact with each other, the third plane is arranged opposite to the second refrigerant outlet and covers the first refrigerant outlet; or the plate heat exchanger also includes a sealing plate, which is arranged on the outer surface of the first end plate, and the sealing plate seals the first refrigerant inlet and the first refrigerant outlet.

[0030] It can be seen that the plate heat exchanger is adaptable to a single refrigerant system, has a simple structure, and can use the same set of plate molds as the above-mentioned dual refrigerant system, thereby reducing production costs and improving processing efficiency.

[0031] To achieve the third objective, the present invention provides a unit comprising the plate heat exchanger described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural diagram of the first embodiment of the plate heat exchanger of the present invention.

[0033] Figure 2 It is a structural diagram of the second reinforcing plate in the first embodiment of the plate heat exchanger of the present invention.

[0034] Figure 3 This is a structural diagram of the plate heat exchanger in the first embodiment of the present invention after the heat exchange micro-element structure is hidden in the heat exchange plate.

[0035] Figure 4 It is a partial enlarged view of the position of the refrigerant inlet corner hole after the heat exchange plate hides the heat exchange micro-element structure in the first embodiment of the plate heat exchanger of the present invention.

[0036] Figure 5 It is a structural diagram of the first sealing plane in the first embodiment of the plate heat exchanger of the present invention.

[0037] Figure 6 It is a partial enlarged view of the refrigerant inlet header in the first embodiment of the plate heat exchanger of the present invention.

[0038] Figure 7 It is a partial enlarged view of the refrigerant outlet header in the first embodiment of the plate heat exchanger of the present invention.

[0039] Figure 8 It is a partial enlarged view of the refrigerant inlet header in the first embodiment of the plate heat exchanger of the present invention.

[0040] Figure 9 It is a partial enlarged view of the brine outlet header in the first embodiment of the plate heat exchanger of the present invention.

[0041] Figure 10 This is a schematic diagram of the fluid flow direction of an existing plate heat exchanger used in a dual refrigerant system.

[0042] Figure 11 It is a schematic diagram of the flow channel arrangement and fluid flow direction of an existing plate heat exchanger used in a dual refrigerant system.

[0043] Figure 12 Schematic diagram of the fluid flow direction of the first embodiment of the plate heat exchanger of the present invention.

[0044] Figure 13 It is a schematic diagram of the flow channel arrangement and fluid flow direction of the first embodiment of the plate heat exchanger of the present invention.

[0045] Figure 14 This is a comparison table of heat exchange when the refrigerant is evenly distributed and unevenly distributed between the plates.

[0046] Figure 15 It is a structural diagram of the second embodiment of the plate heat exchanger of the present invention.

[0047] Figure 16 It is a structural diagram of the heat exchange plates in the fourth embodiment of the plate heat exchanger of the present invention.

[0048] Figure 17 It is a partial cross-sectional view of the area near the refrigerant inlet header of the fourth embodiment of the plate heat exchanger of the present invention.

[0049] Figure 18 It is a structural diagram of the heat exchange plates in the fifth embodiment of the plate heat exchanger of the present invention.

[0050] The present invention will be further described below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0051] Plate heat exchanger and unit first embodiment: See also Figures 1 to 9The unit in this embodiment includes a plate heat exchanger. The plate heat exchanger comprises a first end plate 1, a first plate group 2, a second plate group 3, and a second end plate 4, stacked in sequence along a first direction. Copper foil solder is placed between each end plate and the heat exchange plates of each plate group, and the plates are integrally fabricated by vacuum brazing.

[0052] The first plate group 2 includes a plurality of first heat exchange plates 21 stacked in sequence along a first direction. Adjacent first heat exchange plates 21 form first refrigerant channels 22 and first secondary coolant channels 23 that are fluidically isolated from each other.

[0053] The second plate group 3 includes a plurality of second heat exchange plates 31 stacked in sequence along the first direction, and second refrigerant channels 32 and second coolant channels 33 that are fluidically isolated from each other are formed between adjacent second heat exchange plates 31. The second coolant channels 33 are interconnected with the first coolant channels 23, and the first refrigerant channels 22 and the second refrigerant channels 32 are fluidically isolated from each other.

[0054] The first plate group 2 is provided with a first refrigerant inlet header 24, a first refrigerant outlet header 25, a first secondary coolant inlet header 26 and a first secondary coolant outlet header 27. Figure 3 As shown, the first heat exchange plate 21 includes a refrigerant inlet angular hole 215, a refrigerant outlet angular hole 216, a coolant inlet angular hole 217 and a coolant outlet angular hole 218. After multiple first heat exchange plates 21 are stacked together, each refrigerant inlet angular hole 215 forms a first refrigerant inlet manifold 24, each refrigerant outlet angular hole 216 forms a first refrigerant outlet manifold 25, each coolant inlet angular hole 217 forms a first coolant inlet manifold 26, and each refrigerant outlet angular hole 216 forms a first coolant outlet manifold 27.

[0055] The second plate group 3 is provided with a second refrigerant inlet header 34 , a second refrigerant outlet header 35 , a second brine inlet header 36 and a second brine outlet header 37 .

[0056] The first refrigerant inlet header 24 and the first refrigerant outlet header 25 are both connected to the first refrigerant channel 22, the second refrigerant inlet header 34 and the second refrigerant outlet header 35 are both connected to the second refrigerant channel 32, and the first secondary refrigerant inlet header 26, the first secondary refrigerant outlet header 27, the second secondary refrigerant inlet header 36 and the second secondary refrigerant outlet header 37 are all connected to the first secondary refrigerant channel 23 and the second secondary refrigerant channel 33.

[0057] The three different media in this embodiment are R1 as the first refrigerant, R2 as the second refrigerant, and water as the coolant. R1 flows in the first refrigerant circulation system formed by the first refrigerant channel 22, the first refrigerant inlet header 24 and the first refrigerant outlet header 25, R2 flows in the second refrigerant circulation system formed by the second refrigerant channel 32, the second refrigerant inlet header 34 and the second refrigerant outlet header 35, and water flows in the coolant circulation system formed by the first coolant inlet header 26, the second coolant inlet header 36, the first coolant channel 23, the second coolant channel 33, the first coolant outlet header 27 and the second coolant outlet header 37.

[0058] The first end plate 1 is provided with a first refrigerant inlet 11 and a first refrigerant outlet 12 . The first refrigerant inlet header 24 is opposite to and communicates with the first refrigerant inlet 11 , and the first refrigerant outlet header 25 is opposite to and communicates with the first refrigerant outlet 12 .

[0059] The second end plate 4 is provided with a second refrigerant inlet 41, a second refrigerant outlet 42, a brine inlet 43, and a brine outlet 44. The first refrigerant inlet 11 and the second refrigerant inlet 41 are arranged opposite each other in the first direction, and the first refrigerant outlet 12 and the second refrigerant outlet 42 are arranged opposite each other in the first direction. The second refrigerant inlet header 34 is opposite and connected to the second refrigerant inlet 41, the second refrigerant outlet header 35 is opposite and connected to the second refrigerant outlet 42, the first brine inlet header 26 and the second brine inlet header 36 are both opposite and connected to the brine inlet 43, and the first brine outlet header 27 and the second brine outlet header 37 are both opposite and connected to the brine outlet 44.

[0060] The size of the first refrigerant inlet 11 is equal to that of the second refrigerant inlet 41, and the sizes of the first refrigerant outlet 12, the second refrigerant outlet 42, the brine inlet 43, and the brine outlet 44 are all larger than the sizes of the first refrigerant inlet 11 and the second refrigerant inlet 41. In this embodiment, the refrigerant inlet and the brine inlet are all circular. Therefore, the diameters of the first refrigerant outlet 12, the second refrigerant outlet 42, the brine inlet 43, and the brine outlet 44 are all larger than the diameters of the first refrigerant inlet 11 and the second refrigerant inlet 41. By designing the refrigerant inlet to be smaller than the sizes of the other corner holes, the problem of uneven flow distribution between channels caused by a sudden expansion of the cross section causing a decrease in flow velocity is avoided.

[0061] The inner diameters of the first refrigerant inlet header 24 and the second refrigerant inlet header 34 are both equal to the diameter of the first refrigerant inlet 11, the inner diameters of the first refrigerant outlet header 25 and the second refrigerant outlet header 35 are both equal to the diameter of the second refrigerant outlet 42, the inner diameters of the first secondary refrigerant inlet header 26 and the second secondary refrigerant inlet header 36 are both equal to the diameter of the secondary refrigerant inlet 43, and the inner diameters of the first secondary refrigerant outlet header 27 and the second secondary refrigerant outlet header 37 are both equal to the diameter of the secondary refrigerant outlet 44.

[0062] The heat exchange plates in this embodiment have two structural types. The first plate group 2 and the second plate group 3 are both composed of heat exchange plates of the two structural types stacked alternately in sequence.

[0063] The first heat exchange plate 21 is provided with a first flanged surface 211, which is set at an angle to the main body of the first heat exchange plate 21. The first flanged surface 211 is provided with two first anti-mock notches 212 spaced apart, and the first anti-mock notches 212 are located near one of the corners of the first heat exchange plate 21. The second heat exchange plate 31 is provided with a second flanged surface (not shown), which is set at an angle to the main body of the second heat exchange plate 31. The second anti-mock notches are provided on the second flanged surface, and the second anti-mock notches are located near one of the corners of the second heat exchange plate 31. The anti-mock notches on the flanged surface facilitate identification of plate type and installation direction during assembly.

[0064] A first sealing plane 213 is further provided on the side of the first heat exchange plate 21 where the first refrigerant channel 23 is formed. The first sealing plane 213 is perpendicular to the first direction and connected to the first flanged plane 211. The first sealing plane 213 is provided at at least one of the four corners of the first heat exchange plate 21. Preferably, in this embodiment, the first sealing plane 213 is provided at each of the four corners of the first heat exchange plate 21. A second sealing plane (not shown) is further provided on the side of the second heat exchange plate 31 where the second refrigerant channel 33 is formed. The second sealing plane is perpendicular to the first direction and connected to the second flanged plane. The second sealing plane is provided at at least one of the four corners of the second heat exchange plate 31. Preferably, in this embodiment, the second sealing plane is provided at each of the four corners of the first heat exchange plate 21. After assembly and welding, on the side of the refrigerant channel, the sealing surfaces of the two adjacent heat exchange plates fit together to form a inferior arc-shaped sealing surface. When the refrigerant is water, the edge of the heat exchange plate is prone to form a flow channel dead zone, leading to freezing and cracking problems. Through the design of the sealing plane, after assembly and welding, on the side of the refrigerant channel, a sealing surface is formed here to avoid the risk of water accumulation and freezing and cracking.

[0065] The first sealing plane 213 is a minor arc. Its curved edge 2131 connects to the first flanged surface 211, while its straight edge 2132 connects to the heat exchange element 210 of the first heat exchange plate 21. The connection is rounded to create a transition. The second sealing plane is a minor arc. Its curved edge connects to the second flanged surface, while its straight edge connects to the heat exchange element of the second heat exchange plate 31.

[0066] See also Figure 6 and Figure 7 Two gaskets 5 are positioned between the first plate group 2 and the second plate group 3. The first gasket 5 is positioned opposite the first refrigerant inlet 11 in the first direction and between the first refrigerant inlet angular hole plane 214 of the first heat exchange plate 21 and the second refrigerant inlet angular hole plane 314 of the second heat exchange plate 31. This gasket 5 fluidically isolates the first refrigerant inlet header 24 from the second refrigerant inlet header 34. The other gasket 5 is positioned opposite the first refrigerant outlet 12 in the first direction and between the first refrigerant outlet angular hole plane 219 of the first heat exchange plate 21 and the second refrigerant outlet angular hole plane 319 of the second heat exchange plate 31. This gasket 5 fluidically isolates the first refrigerant outlet header 25 from the second refrigerant outlet header 35. The gasket 5 is a circular, plate-shaped seal made of elastic material that separates the first and second refrigerant circulation systems. The gasket 5 not only separates the flow paths but also provides stable support. At the same time, the number of channels of the two systems can be reasonably allocated according to the flow rate by adjusting the position of the gasket 5. The number of first heat exchange plates 21 in the first plate group 2 and the number of second heat exchange plates 31 in the second plate group 3 can be changed as needed, and the two can be the same or different.

[0067] The plate heat exchanger also includes a first reinforcing plate 61, a second reinforcing plate 62, a third reinforcing plate (not shown), a fourth reinforcing plate (not shown) and six joints 7. Each reinforcing plate is a rectangular metal plate with rounded corners. The reinforcing plate is arranged between the corresponding joint 7 and the corresponding end plate. The thickness of the reinforcing plate is greater than or equal to the thickness of the end plate and is at least 2 mm. It is used to improve the pressure resistance of the plate heat exchanger. The first and second reinforcing plates 61 and 62 are both disposed on the outer surface of the second end plate 4. The first reinforcing plate 61 defines a first and second corner holes 611 and 612, with the first corner hole 611 coaxially arranged with the second refrigerant inlet 41 and the second corner hole 612 coaxially arranged with the secondary refrigerant outlet 44. The second reinforcing plate 62 defines a third and fourth corner hole 621 and 622 coaxially arranged with the second refrigerant outlet 42 and the secondary refrigerant inlet 43. The third and fourth reinforcing plates are both disposed on the outer surface of the first end plate 1. The third reinforcing plate defines a fifth corner hole coaxially arranged with the first refrigerant inlet 11, while the fourth reinforcing plate defines a sixth corner hole coaxially arranged with the first refrigerant outlet 12. Joints 7 are clearance-matched with the corresponding corner holes, with a clearance of 0.1 mm. The joints are pre-secured to the end plates by expansion joints. In this embodiment, each end plate is formed by die stamping, while each reinforcing plate is formed by laser cutting.

[0068] Figure 10 and 11 Schematic diagram of the medium flow direction of the dual-system plate heat exchanger in the prior art. Six corner holes are opened on the heat exchange plate. The two corner holes in the middle are respectively the water inlet corner hole 101 and the water outlet corner hole 102. The four corner holes on both sides are respectively the first refrigerant inlet corner hole 103, the first refrigerant outlet corner hole 104, the second refrigerant inlet corner hole 105 and the second refrigerant outlet corner hole 106. Figure 11 As shown, the lengths of the first refrigerant inlet header 107 and the second refrigerant inlet header 108 are both relatively long, which may result in uneven distribution of the fluid between the refrigerant plates, thereby reducing the capacity of the heat exchanger. Figure 12 and 13 Figure 1 is a schematic diagram of the medium flow direction of the dual-system plate heat exchanger in this embodiment. Compared with the prior art, the lengths of the first refrigerant inlet header 107 and the second refrigerant inlet header 108 in this embodiment are halved, thereby reducing the problem of uneven distribution of refrigerant fluid between the plates and improving the uniformity of refrigerant flow distribution between the plates by more than 30%. Figure 14 This is a comparison table of heat transfer rates when the refrigerant is evenly and unevenly distributed between the plates. The figure shows the capacity degradation percentage under different operating conditions. σ represents the unevenness of distribution. The larger the value, the more uneven the flow distribution. Under the same inlet conditions, x = 0.1, G = 7.5 kg m -2 ﹒ s -1 The inlet header of a heat exchanger with 50 plates is shorter than that of a heat exchanger with 100 plates. The smaller its σ is, the more uniform the distribution is, and the heat transfer rate can be increased by more than 10%.

[0069] As can be seen from the above, this plate heat exchanger can be used in dual refrigerant systems. A single heat exchange plate in this plate heat exchanger has only four corner holes, which can achieve heat exchange between three different media at the same time. Compared with the existing heat exchange plate structure with six corner holes, it reduces the difficulty of assembly, simplifies the production process, effectively reduces processing costs, and improves production reliability. At the same time, there is no need to adjust the heat exchange plate structure, and it can be converted into a plate heat exchanger for a single refrigeration system, reducing mold opening costs. In addition, compared with existing plate heat exchangers, the length of the refrigerant inlet and outlet headers are both reduced, thereby reducing the problem of uneven fluid distribution between the refrigerant plates.

[0070] The second embodiment of the plate heat exchanger and the unit: As an explanation of the second embodiment of the plate heat exchanger and the unit of the present invention, only the differences from the first embodiment of the plate heat exchanger and the unit are described below.

[0071] See also Figure 15 The plate heat exchanger of this embodiment includes a first end plate 210, a second plate group 230, and a second end plate 240 stacked in sequence along a first direction. In other words, compared to the first embodiment, the plate heat exchanger of this embodiment does not include the first plate group 2, thereby forming a plate heat exchanger suitable for use in a single refrigerant system.

[0072] The structure of the second plate assembly 230 in this embodiment is identical to that of the second plate assembly 3 in the first embodiment. The second plate assembly 230 includes a plurality of second heat exchange plates 231 stacked sequentially along a first direction. Adjacent second heat exchange plates 231 form fluidically isolated second refrigerant channels and second coolant channels. The first end plate 210 defines a first refrigerant inlet and a first refrigerant outlet. The second end plate 240 defines a second refrigerant inlet 241, a second refrigerant outlet 242, a coolant inlet 243, and a coolant outlet 244. Both the second refrigerant inlet 241 and the second refrigerant outlet 242 communicate with the second refrigerant channels, while both the coolant inlet 243 and the coolant outlet 244 communicate with the second coolant channels.

[0073] In this embodiment, the plate heat exchanger further includes two sealing plates (not shown) made of metal material. No corner holes are provided on the two sealing plates. Both sealing plates are arranged on the outer surface of the first end plate 210 and are respectively located at the two ends of the length direction of the first end plate 210. The two sealing plates respectively seal the first refrigerant inlet and the first refrigerant outlet.

[0074] It can be seen that the plate heat exchanger only needs a few modifications to adapt to the single refrigerant system. It has a simple structure and can use the same set of plate molds as the plate heat exchanger of the dual refrigerant system in the first embodiment above, which reduces production costs and improves processing efficiency.

[0075] The third embodiment of the plate heat exchanger and the unit: As an explanation of the third embodiment of the plate heat exchanger and the unit of the present invention, only the differences from the second embodiment of the plate heat exchanger and the unit described above are described below.

[0076] In this embodiment, no through holes are provided on the second plane and the third plane of the two second heat exchange plates arranged near the first end plate in the second plate group, the second planes of the two second heat exchange plates are in contact with each other, the second planes are arranged opposite to the second refrigerant inlet and cover the first refrigerant inlet, and the third planes of the two second heat exchange plates are in contact with each other, the third planes are arranged opposite to the second refrigerant outlet and cover the first refrigerant outlet, so there is no need to set a sealing plate.

[0077] Fourth embodiment of the plate heat exchanger and unit: As an explanation of the fourth embodiment of the plate heat exchanger and the unit of the present invention, only the differences from the first embodiment of the plate heat exchanger and the unit are described below.

[0078] See also Figure 16 and 17 In this embodiment, the first plane 4214 of the two first heat exchange plates 421 in the first plate group 420, located near the second plate group 430, has no through-holes. The first planes 4214 of the two first heat exchange plates 421 are aligned with each other, and the first plane 4214 is opposite the first refrigerant inlet. The first plane in this embodiment is the first refrigerant inlet corner hole plane 214 in this embodiment. The second plane 4314 of the two second heat exchange plates 431 in the second plate group 430, located near the first plate group 420, has no through-holes. The second planes 4314 of the two second heat exchange plates 431 are aligned with each other, and the second plane 4314 is opposite the second refrigerant inlet. The second plane 4314 in this embodiment is the second refrigerant inlet corner hole plane 314 in this embodiment. A gasket 450 is clamped between the first plane 4214 and the second plane 4314.

[0079] Optionally, the third plane 4212 of the two first heat exchange plates 421 in the first plate group 420, positioned near the second plate group 430, also has no through-holes. The third planes 4212 of the two first heat exchange plates 421 abut against each other, and the third plane 4212 is positioned opposite the first refrigerant outlet. The third plane in this embodiment corresponds to the first refrigerant outlet corner hole plane 219 in the first embodiment. The fourth plane of the two second heat exchange plates 431 in the second plate group 430, positioned near the first plate group 420, has no through-holes. The fourth planes of the two second heat exchange plates 431 abut against each other, and the fourth plane is positioned opposite the second refrigerant outlet. The fourth plane in this embodiment corresponds to the second refrigerant outlet corner hole plane 319 in the first embodiment. Another gasket is clamped between the third plane 4212 and the fourth plane.

[0080] It can be seen that no through holes are provided on the first plane and the second plane, thereby achieving mutual fluid isolation between the first refrigerant channel and the second refrigerant channel, enhancing the local thickness, and further improving the sealing effect and pressure bearing capacity of the heat exchanger.

[0081] The fifth embodiment of the plate heat exchanger and the unit: As an explanation of the fifth embodiment of the plate heat exchanger and the unit of the present invention, only the differences from the first embodiment of the plate heat exchanger and the unit are described below.

[0082] See also Figure 18 In this embodiment, the first refrigerant inlet, second refrigerant inlet, first refrigerant outlet, and second refrigerant outlet are all of equal size. The brine inlet and brine outlet are also of equal size. On the heat exchange plate, the diameters of the refrigerant inlet corner holes 511, refrigerant outlet corner holes 512, brine inlet corner holes 513, and brine outlet corner holes 514 are all equal.

[0083] As can be seen, the four corner holes of the heat exchange plates of this structure are equal in size and arranged symmetrically. In the first plate group and the second plate group, one of the two adjacent heat exchange plates is placed normally, and the other heat exchange plate is rotated 180 degrees and stacked, forming a channel between the two. Therefore, only one type of heat exchange plate is required. Since the heat exchange plates only require one set of molds for processing, processing costs can be reduced. In addition, because the channel is formed by stacking two heat exchange plates of the same structure, the volume of the channels on both sides of the heat exchange plate is equal, which is a symmetrical structure suitable for working conditions with a small difference in the flow rate of hot and cold fluids.

[0084] Finally, it should be emphasized that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Plate heat exchanger, characterized in that, comprising a first end plate, a first plate group, a second plate group and a second end plate stacked in sequence along a first direction; The first plate group includes a plurality of first heat exchange plates stacked in sequence along the first direction, and adjacent first heat exchange plates form first refrigerant channels and first secondary coolant channels that are fluidically isolated from each other; The second plate group includes a plurality of second heat exchange plates stacked sequentially along the first direction, wherein adjacent second heat exchange plates form second refrigerant channels and second coolant channels that are fluidically isolated from each other, the second coolant channels are in communication with the first coolant channels, and the first refrigerant channels are fluidically isolated from the second refrigerant channels; The first end plate is provided with a first refrigerant inlet and a first refrigerant outlet, both of which are in communication with the first refrigerant channel; The second end plate is provided with a second refrigerant inlet, a second refrigerant outlet, a coolant inlet and a coolant outlet. The second refrigerant inlet and the second refrigerant outlet are both connected to the second refrigerant channel. The coolant inlet and the coolant outlet are both connected to the second coolant channel.

2. The plate heat exchanger according to claim 1, characterized in that: The first plate group is provided with a first refrigerant inlet header, a first refrigerant outlet header, a first brine inlet header and a first brine outlet header, and the second plate group is provided with a second refrigerant inlet header, a second refrigerant outlet header, a second brine inlet header and a second brine outlet header; The first refrigerant inlet header and the first refrigerant outlet header are both in communication with the first refrigerant channel, the second refrigerant inlet header and the second refrigerant outlet header are both in communication with the second refrigerant channel, and the first brine inlet header, the first brine outlet header, the second brine inlet header, and the second brine outlet header are all in communication with the first brine channel; The first refrigerant inlet header is opposite to and communicates with the first refrigerant inlet, and the first refrigerant outlet header is opposite to and communicates with the first refrigerant outlet; The second refrigerant inlet header is opposite to and connected to the second refrigerant inlet, the second refrigerant outlet header is opposite to and connected to the second refrigerant outlet, the first secondary refrigerant inlet header and the second secondary refrigerant inlet header are both opposite to and connected to the secondary refrigerant inlet, and the first secondary refrigerant outlet header and the second secondary refrigerant outlet header are both opposite to and connected to the secondary refrigerant outlet.

3. The plate heat exchanger according to claim 2, wherein: No through-holes are provided on the first planes of the two first heat exchange plates arranged near the second plate group in the first plate group, the first planes of the two first heat exchange plates are in contact with each other, and the first planes are arranged opposite to the first refrigerant inlet; and / or No through-holes are provided on the second planes of the two second heat exchange plates in the second plate group close to the first plate group. The second planes of the two second heat exchange plates are in contact with each other, and the second planes are arranged opposite to the second refrigerant inlet.

4. The plate heat exchanger according to claim 2 or 3, characterized in that: A first gasket is provided between the first plate group and the second plate group, and the first gasket is arranged opposite to the first refrigerant inlet in the first direction; and / or A second gasket is provided between the first plate group and the second plate group, and the second gasket is arranged opposite to the first refrigerant outlet in the first direction.

5. The plate heat exchanger according to claim 4, characterized in that: The first refrigerant inlet header is fluidly isolated from the second refrigerant inlet header by the first gasket; and / or The first refrigerant outlet header is fluidly isolated from the second refrigerant outlet header by the second gasket.

6. The plate heat exchanger according to any one of claims 1 to 3, characterized in that: The first refrigerant inlet and the second refrigerant inlet are arranged opposite to each other in the first direction, and the first refrigerant outlet and the second refrigerant outlet are arranged opposite to each other in the first direction.

7. The plate heat exchanger according to any one of claims 1 to 3, characterized in that: The size of the first refrigerant inlet is equal to the size of the second refrigerant inlet; and / or The sizes of the first refrigerant outlet, the second refrigerant outlet, the brine inlet, and the brine outlet are all larger than the size of the first refrigerant inlet; and / or The sizes of the first refrigerant outlet, the second refrigerant outlet, the brine inlet, and the brine outlet are all larger than the size of the second refrigerant inlet.

8. The plate heat exchanger according to any one of claims 1 to 3, characterized in that: The sizes of the first refrigerant inlet, the second refrigerant inlet, the first refrigerant outlet, and the second refrigerant outlet are all equal, and the sizes of the brine inlet and the brine outlet are all equal.

9. The plate heat exchanger according to any one of claims 1 to 3, characterized in that: The plate heat exchanger further includes a first reinforcing plate, the first reinforcing plate being arranged on the outer surface of the second end plate, the first reinforcing plate being provided with a first corner hole and a second corner hole, the first corner hole being arranged coaxially with the second refrigerant inlet, and the second corner hole being arranged coaxially with the secondary refrigerant outlet; and / or The plate heat exchanger also includes a second reinforcing plate, which is arranged on the outer surface of the second end plate. A third corner hole and a fourth corner hole are opened on the second reinforcing plate. The third corner hole is coaxially arranged with the second refrigerant outlet, and the fourth corner hole is coaxially arranged with the coolant inlet.

10. The plate heat exchanger according to any one of claims 1 to 3, characterized in that: The first heat exchange plate is provided with a first flange plane, the first flange plane is arranged at an angle with the plate body of the first heat exchange plate, the first flange plane is provided with a first fool-proof notch, and the first fool-proof notch is arranged near one of the corners of the first heat exchange plate; and / or A second flange plane is provided on the second heat exchange plate, and the second flange plane is set at an angle with the plate body of the second heat exchange plate. A second fool-proof notch is opened on the second flange plane, and the second fool-proof notch is set close to one of the corners of the second heat exchange plate.

11. The plate heat exchanger according to claim 10, characterized in that: A first sealing plane is further provided on one side of the first heat exchange plate where the first coolant channel is formed. The first sealing plane is perpendicular to the first direction and connected to the first flange plane. The first sealing plane is provided at at least one of the four corners of the first heat exchange plate; and / or A second sealing plane is also provided on the side of the second heat exchange plate where the second refrigerant channel is formed. The second sealing plane is perpendicular to the first direction and connected to the second flange plane. The second sealing plane is provided at at least one of the four corners of the second heat exchange plate.

12. The plate heat exchanger according to claim 11, characterized in that: The first sealing plane is in a minor arc shape, the arc edge of the first sealing plane is connected to the first flange plane, and the straight edge of the first sealing plane is connected to the heat exchange element of the first heat exchange plate; and / or The second sealing plane is in the shape of a minor arc, the arc edge of the second sealing plane is connected to the second flange plane, and the straight edge of the second sealing plane is connected to the heat exchange element of the second heat exchange plate.

13. A plate heat exchanger comprising a first end plate, a second plate group, and a second end plate stacked in sequence along a first direction; The second plate group includes a plurality of second heat exchange plates stacked in sequence along the first direction, and adjacent second heat exchange plates form second refrigerant channels and second coolant channels that are fluidically isolated from each other; Its characteristics are: A first refrigerant inlet and a first refrigerant outlet are formed on the first end plate; The second end plate is provided with a second refrigerant inlet, a second refrigerant outlet, a brine inlet, and a brine outlet. The second refrigerant inlet and the second refrigerant outlet are both communicated with the second refrigerant channel. The brine inlet and the brine outlet are both communicated with the second brine channel. The second and third planes of the two second heat exchange plates arranged near the first end plate in the second plate group have no through holes, the second planes of the two second heat exchange plates are in contact with each other, the second planes are arranged opposite to the second refrigerant inlet and cover the first refrigerant inlet, and the third planes of the two second heat exchange plates are in contact with each other, the third planes are arranged opposite to the second refrigerant outlet and cover the first refrigerant outlet; or The plate heat exchanger further includes a sealing plate disposed on an outer surface of the first end plate, and the sealing plate seals the first refrigerant inlet and the first refrigerant outlet.

14. The unit is characterized in that The method comprises the plate heat exchanger according to any one of claims 1 to 13.

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