Plate heat exchanger

Abstract

The application provides a plate heat exchanger, comprising a plurality of first heat exchange plates and a plurality of second heat exchange plates; the plate heat exchanger has a first inter-plate channel and a second inter-plate channel, the first inter-plate channel is located between the front surface of the second heat exchange plate and the adjacent first heat exchange plate, and the second inter-plate channel is located between the back surface of the second heat exchange plate and the adjacent first heat exchange plate; the first heat exchange plate and the second heat exchange plate have corresponding first corner holes, the first corner holes are communicated with the first inter-plate channel; the first heat exchange plate has a first flat joint and a second flat joint, the front surface of the second flat joint is arranged at intervals with the adjacent first flat joint; the plate heat exchanger comprises at least one connecting part, and the connecting part connects the front surface of the second flat joint and the adjacent first flat joint. The plate heat exchanger provided by the application improves the connecting strength between the front surface of the second flat joint arranged at intervals and the adjacent first flat joint by arranging the connecting part.

Description

Technical Field

[0001] This invention belongs to the field of heat exchangers, specifically, it relates to a plate heat exchanger. Background Technology

[0002] Plate heat exchangers are widely used in refrigeration and heating systems as evaporators, condensers, economizers, etc., due to their advantages such as compact structure, high heat transfer coefficient, high reliability, and low refrigerant charge.

[0003] The corner holes of plate heat exchangers typically need to withstand high pressures, so it is essential to increase the strength of the inlet. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a plate heat exchanger that improves connection strength.

[0005] This invention provides a plate heat exchanger, comprising a plurality of first heat exchange plates and a plurality of second heat exchange plates, wherein the plurality of first heat exchange plates and the plurality of second heat exchange plates are stacked alternately along the thickness direction of the plate heat exchanger.

[0006] The plate heat exchanger has a first inter-plate channel and a second inter-plate channel. The first inter-plate channel is located between the front side of the second heat exchange plate and the adjacent first heat exchange plate, and the second inter-plate channel is located between the back side of the second heat exchange plate and the adjacent first heat exchange plate.

[0007] The first heat exchange plate and the second heat exchange plate have corresponding first corner holes, and the first corner holes are connected to the inter-plate channel; the first heat exchange plate has a first flat joint portion, and the first corner hole of the first heat exchange plate is located in the first flat joint portion; the second heat exchange plate has a second flat joint portion, and the first corner hole of the second heat exchange plate is located in the second flat joint portion; the front side of the second flat joint portion is spaced apart from the adjacent first flat joint portion; and the back side of the second flat joint portion is connected to the adjacent first flat joint portion.

[0008] The first heat exchange plate and the second heat exchange plate have corresponding second corner holes, and the second corner holes are connected to the inter-plate channel; on a plane perpendicular to the thickness direction of the plate heat exchanger, the projected area of ​​at least one of the first flat joint and the second flat joint is greater than the projected area of ​​the flat joint of the first heat exchange plate on the periphery of the second corner hole, and the projected area of ​​at least one of the first flat joint and the second flat joint is greater than the projected area of ​​the flat joint of the second heat exchange plate on the periphery of the second corner hole.

[0009] The plate heat exchanger includes at least one connecting portion, which connects the front side of the second flat joint portion and the adjacent first flat joint portion.

[0010] The plate heat exchanger provided by the present invention improves the connection strength between the front side of the spaced-apart second flat joint and the adjacent first flat joint by setting a connecting part. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a perspective view of a plate heat exchanger provided in an embodiment of the present invention;

[0013] Figure 2 This is a partial structural schematic diagram of a plate heat exchanger provided in an embodiment of the present invention;

[0014] Figure 3 An exploded view of a plate heat exchanger provided in an embodiment of the present invention;

[0015] Figure 4 This is a partial cross-sectional view of a plate heat exchanger provided in an embodiment of the present invention;

[0016] Figure 5 for Figure 4 Enlarged view of the structure of section A;

[0017] Figure 6 This is a partial cross-sectional view of a plate heat exchanger at the first corner hole, provided in an embodiment of the present invention.

[0018] Figure 7 This is a partial exploded view of a plate heat exchanger provided in an embodiment of the present invention;

[0019] Figure 8 This is an exploded view of the front of the second heat exchange plate provided in this embodiment and the adjacent first heat exchange plate;

[0020] Figure 9 This is a structural diagram of a connecting block used in an embodiment of the present invention;

[0021] Figure 10 This is an exploded view of the back side of the second heat exchange plate provided in this embodiment and the adjacent first heat exchange plate;

[0022] Figure 11 This is a front view of the first heat exchange plate provided in an embodiment of the present invention;

[0023] Figure 12 This is a front view of the second heat exchange plate provided in an embodiment of the present invention;

[0024] Figure 13 This is a structural diagram of the first heat exchange plate and the second heat exchange plate at the first corner hole in an embodiment of the present invention;

[0025] Figure 14 This is another partially exploded view of a plate heat exchanger provided in an embodiment of the present invention;

[0026] Figure 15 This is a partial cross-sectional view of a plate heat exchanger at the second corner hole, provided in an embodiment of the present invention. Detailed Implementation

[0027] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] like Figures 1 to 15 As shown, this embodiment provides a plate heat exchanger including multiple first heat exchange plates 1 and multiple second heat exchange plates 2. The multiple first heat exchange plates 1 and multiple second heat exchange plates 2 are alternately stacked along the thickness direction of the plate heat exchanger. The plate heat exchanger has a first inter-plate channel 3 and a second inter-plate channel 4. The first inter-plate channel 3 is located between the front side of the second heat exchange plate 2 and the adjacent first heat exchange plate 1, and the second inter-plate channel 4 is located between the back side of the second heat exchange plate 2 and the adjacent first heat exchange plate 1. That is, the first inter-plate channel 3 and the second inter-plate channel 4 are along the thickness direction of the plate heat exchanger (i.e.,...). Figure 2The plates are alternately distributed (in the X direction shown). The first heat exchange plate 1 and the second heat exchange plate 2 have corresponding first corner holes F1, which communicate with the first inter-plate channel 3. The first heat exchange plate 1 has a first flat joint 1a, with the first corner hole F1 located within the first flat joint 1a. The second heat exchange plate 2 has a second flat joint 2a, with the first corner hole F1 located within the second flat joint 2a. The front side of the second flat joint 2a is spaced apart from the adjacent first flat joint 1a, and the back side of the second flat joint 2a is connected to the adjacent first flat joint 1a. In this embodiment, the first inter-plate channel 3 is used for refrigerant flow, the first corner hole F1 is used for refrigerant to flow into the first inter-plate channel 3, and the second inter-plate channel 4 is used for heat exchange medium (such as water) that exchanges heat with the refrigerant in the first inter-plate channel 3. The second inter-plate channel 4 is not connected to the first inter-plate channel 3. The first heat exchange plate 1 and the second heat exchange plate 2 have corresponding second corner holes F2, which are connected to the first inter-plate channel 3 and are used for refrigerant to flow out of the corresponding first inter-plate channel 3. On a plane perpendicular to the thickness direction of the plate heat exchanger, at least one of the first flat joint portion 1a and the second flat joint portion 2a has a projected area in the plane that is larger than the projected area of ​​the flat joint portion of the first heat exchange plate 1 around the second corner hole F2 in the plane, and at least one of the first flat joint portion 1a and the second flat joint portion 2a has a projected area in the plane that is larger than the projected area of ​​the flat joint portion of the second heat exchange plate 2 around the second corner hole F2 in the plane. In this embodiment, both the first corner hole F1 and the second corner hole F2 are connected to the first inter-plate channel 3. The first corner hole F1 is located at the junction of the first flat joint 1a and the second flat joint 2a, and the area of ​​the flat joint around the first corner hole F1 is larger than the area of ​​the flat joint around the second corner hole F2.

[0030] In this embodiment, the heat exchange plates have a front and a back, such as Figure 14 As shown, the front of the second heat exchange plate 2 faces the X1 direction, and the back of the second heat exchange plate 2 faces the X2 direction. "The first interplate channel 3 is located between the front of the second heat exchange plate 2 and the adjacent first heat exchange plate 1" means that the first interplate channel 3 is located between the front of the second heat exchange plate 2 and the back of the adjacent first heat exchange plate 1. Similarly, "The second interplate channel 4 is located between the back of the second heat exchange plate 2 and the adjacent first heat exchange plate 1" means that the second interplate channel 4 is located between the back of the second heat exchange plate 2 and the front of the adjacent first heat exchange plate 1.

[0031] In existing plate heat exchangers, the temperature at the refrigerant inlet is low, and the heat exchange medium flowing to the corresponding position of the refrigerant inlet is at high risk of freezing. Once freezing occurs, it can easily lead to volume expansion, causing the heat exchange plates in the frozen area to crack or break under stress, resulting in refrigerant bypassing to the heat exchange medium side and causing the plate heat exchanger to fail. To reduce or prevent freezing of the heat exchange medium at this location, in this embodiment, the front of the first heat exchange plate 1 and the back of the second heat exchange plate 2 are connected at the first corner hole F1 by a first flat joint 1a and a second flat joint 2a, and the first corner hole F1 is located within the first flat joint 1a and the second flat joint 2a. This allows the second interplate channel 4 to be closed at the corresponding position of the first corner hole F1 by the first flat joint 1a and the second flat joint 2a, ensuring that the edge of the second interplate channel 4 is spaced from the first corner hole F1, preventing the fluid in the second interplate channel 4 from flowing to the corresponding position of the first corner hole F1. When the plate heat exchanger is used as an evaporator, the heat exchange medium in the second interplate channel 4 will not flow to the corresponding position of the first corner hole F1, and there will be no problem of the heat exchange medium stagnating at the corresponding position of the first corner hole F1. This prevents the heat exchange medium from freezing due to the low temperature of the refrigerant in the first interplate channel 3 at the first corner hole F1, effectively extending the life of the plate heat exchanger when used as an evaporator and improving its durability.

[0032] In some embodiments, the front side of the first flat joint 1a and the back side of the second flat joint 2a are connected by a plane. The connection method is not specifically limited. It can be that the first flat joint 1a and the second flat joint 2a are brazed with copper foil, or they can be bonded, etc.

[0033] Please refer to it again. Figure 2 , Figure 5 and Figure 10The back side of the second heat exchange plate 2 is connected to the adjacent first heat exchange plate 1 through the first flat joint 1a and the second flat joint 2a, resulting in a large planar structure between the front side of the second heat exchange plate 2 and the back side of the adjacent first heat exchange plate 1. This creates a large space between the front side of the second flat joint 2a and the back side of the adjacent first flat joint 1a. When the first interplate channel 3 is used to circulate refrigerant, the first corner hole F1, as the refrigerant inlet, needs to withstand a large pressure, which can easily cause the plane at that point to deform, resulting in tearing of the joint. In severe cases, the plate may tear due to stress, allowing the refrigerant to bypass to the heat exchange medium side, leading to the failure of the plate heat exchanger. Therefore, in order to improve the strength at the refrigerant inlet, the plate heat exchanger in this embodiment further includes at least one connecting part 5. The connecting part 5 connects the front side of the second flat joint 2a and the adjacent first flat joint 1a, so that the first flat joint 1a and the second flat joint 2a on both sides of the first corner hole F1 position of the first plate channel 3 are connected by the connecting part 5. That is, by setting the connecting part 5, the connection strength between the front side of the spaced second flat joint and the adjacent first flat joint is improved, which significantly improves the strength between the plates in the refrigerant inlet area and improves the pressure resistance, reliability and durability of the plate heat exchanger.

[0034] Please combine Figure 8 In some embodiments, the connecting portion 5 includes a boss 51. At least one of the first flat-joint portion 1a and the second flat-joint portion 2a has a boss 51, which protrudes toward the first inter-plate channel 3. In this embodiment, the first flat-joint portion 1a may have a boss 51, or both the first flat-joint portion 1a and the second flat-joint portion 2a may have bosses 51. When both the first flat-joint portion 1a and the second flat-joint portion 2a have bosses 51, the bosses 51 on the first flat-joint portion 1a and the bosses 51 on the second flat-joint portion 2a correspond along the thickness direction of the plate heat exchanger, ensuring that the bosses 51 of the two plates can be connected in a corresponding manner when the plates are stacked. This embodiment is illustrated by taking an example where both the first flat joint 1a and the second flat joint 2a have bosses 51. The boss 51 on the first flat joint 1a is part of the first heat exchange plate 1 and is an integral structure with the first heat exchange plate 1. It can be pressed during the production process of the first heat exchange plate 1. Similarly, the boss 51 on the second flat joint 2a is part of the second heat exchange plate 2 and is an integral structure with the second heat exchange plate 2. It can be pressed during the production process of the second heat exchange plate 2. By integrally molding the bosses 51 with the heat exchange plates, the structural strength of the heat exchange plates can be improved. The bosses 51 have a first contact surface 51a for connection. The width of the first contact surface 51a is greater than or equal to 0.5 mm to ensure a firm connection.

[0035] Please combine Figure 9In other embodiments, the connecting portion 5 includes a connecting block 52 located within the first inter-plate channel 3. The connecting block 52 is connected to the first flat joint portion 1a and the second flat joint portion 2a on both sides of the first inter-plate channel 3. In this embodiment, the connecting block 52 is placed in the corresponding position during the stacking of heat exchange plates and then connected to the heat exchange plates by brazing or bonding. In this embodiment, the connecting block 52 has a second contact surface 52a, the width of which is greater than or equal to 0.5 mm to ensure a firm connection.

[0036] In the above embodiments, the shape of the contact surface of the connecting part 5 is not specifically limited, and can be dot-shaped, ring-shaped, strip-shaped, corrugated, etc.

[0037] Please combine Figure 8 , Figures 10 to 12 The plate heat exchanger has a rim 6, which in this embodiment is the outer edge of the heat exchange plate. In this embodiment, the rim 6 is folded from the front to the back of the heat exchange plate. Please refer to... Figure 5 There is a flow gap 3a between the connecting part 5 and the edge 6, which is conducive to the refrigerant flowing through the flow gap 3a, which is conducive to enhancing the distribution effect of the refrigerant and improving the distribution uniformity. At the same time, it avoids the problem of refrigerant stagnation at this point due to the connection between the connecting part 5 and the edge 6, which would lead to the freezing of the heat exchange medium at the corresponding position of the second plate channel 4.

[0038] In this embodiment, the edging 6 includes a first side 61 and a second side 62. Specifically, there are two first sides 61 and two second sides 62, with the two first sides 61 facing each other and the two second sides 62 facing each other. The first sides 61 and the second sides 62 are connected, and the connection point between the first sides 61 and the second sides 62 is rounded. Around the first corner hole F1, the edge of the second inter-plate channel 4 connects the first side 61 and the second side 62, and the first corner hole F1 is located between the edge of the second inter-plate channel 4 and the outer edge of the corner near the first corner hole F1. The length of the first side 61 is greater than the length of the second side 62.

[0039] Please refer to it again. Figure 13Furthermore, to ensure the smooth flow and guidance of the heat exchange medium within the second interplate channel 4 from the periphery of the first corner hole F1, and to prevent the heat exchange medium from freezing due to the low temperature of the refrigerant near the first corner hole F1, the vertical distance from a point on the edge of the second interplate channel 4 to the second side 62 decreases along the line from the first side 61 to the second side 62. This can be a decreasing trend, thus avoiding the problem of stagnation zones. Even further, the edge of the second interplate channel 4 forms a first angle α with the first side 61, with the angle α pointing towards the first corner hole F1. The angle α is 10° ≤ 30°. This high-inclination flow-guiding design improves the flow effect of the heat exchange medium at the edge of the second interplate channel 4, reduces the flow time of the heat exchange medium at that location, and reduces the risk of freezing. Furthermore, the edge of the second inter-plate channel 4 forms a second included angle β with the second side 62, and the angle of the second included angle β faces the first corner hole F1. The angle of the second included angle β is 70° ≤ 90°. This design also employs a large-inclination flow guide to reduce the risk of freezing while minimizing the space occupied by the second inter-plate channel 4. This ensures the heat exchange area between the second inter-plate channel 4 and the first inter-plate channel 3, guaranteeing heat exchange performance and effect. In this embodiment, the minimum distance from the edge of the second inter-plate channel 4 to the edge of the first corner hole F1 is greater than or equal to 2mm, such as 2.5mm, 3mm, 3.5mm, 4mm, 5mm, etc. This ensures that the heat exchange medium in the second inter-plate channel 4 has sufficient space from the first corner hole F1, reducing the risk of freezing and ensuring connection strength and improved durability.

[0040] Please refer to it again. Figure 4 Angles 10° ≤ first included angle α ≤ 30° and angles 70° ≤ second included angle β ≤ 90° are provided, resulting in a large planar area on at least a portion of the heat exchange plate around the first corner hole F1. This creates an empty area in the first inter-plate channel 3 at the corresponding position. To enhance the strength of the plate heat exchanger at this location, a connecting part 5 is provided. Further, the area between the edge of the second inter-plate channel 4, the first side 61, and the edge of the first corner hole F1 is defined as the first region Q1, and at least one connecting part 5 is located in the first region Q1. Alternatively, the area between the edge of the second inter-plate channel 4, the second side 62, and the edge of the first corner hole F1 is defined as the second region Q2, and at least one connecting part 5 is located in the second region Q2. In this embodiment, both the first region Q1 and the second region Q2 are provided with connecting parts 5, and the number and distribution of connecting parts 5 within these regions can be selected according to actual needs.

[0041] In the above embodiment, the edge of the second inter-plate channel 4 is the boundary near the side of the second inter-plate channel 4 where the first flat joint 1a and the second flat joint 2a meet, such as... Figure 13 As shown by the thick dashed line in the middle.

[0042] Please refer to it again. Figure 11 and Figure 12 In the above embodiment, the first heat exchange plate 1 and the second heat exchange plate 2 are corrugated plates; the first heat exchange plate 1 has a first corrugation 11, which extends to the edge of the first flat joint 1a; the second heat exchange plate 2 has a second corrugation 21, which extends to the edge of the second flat joint 2a. In this embodiment, both the first corrugation 11 and the second corrugation 21 are herringbone waves, and the angular direction of the first corrugation 11 is opposite to that of the second corrugation 21. In this embodiment, the number of herringbone waves is not specifically limited; it can be a single herringbone wave or a double or more herringbone waves. The number of herringbone waves in the first corrugation 11 and the second corrugation 21 can be the same or different. In addition, the angular angles of the first corrugation 11 and the second corrugation 21 can be the same or different.

[0043] Please refer to it again. Figure 2 and Figure 4 In the above embodiments, the first heat exchange plate 1 and the second heat exchange plate 2 have corresponding third corner holes F3, which are connected to the second inter-plate channel 4. The first heat exchange plate 1 and the second heat exchange plate 2 also have corresponding fourth corner holes F4, which are connected to the second inter-plate channel 4. Of the third corner hole F3 and the fourth corner hole F4, one serves as the inlet for the heat exchange medium entering the corresponding second inter-plate channel 4, and the other serves as the outlet for the heat exchange medium flowing out of the corresponding second inter-plate channel 4. In this embodiment, the one of the third corner hole F3 and the fourth corner hole F4 that is farther from the first corner hole F1 serves as the inlet for the heat exchange medium. In this embodiment, the fourth corner hole F4 is used as the heat exchange medium inlet, and the third corner hole F3 is used as the heat exchange medium outlet. The heat exchange medium enters the second inter-plate channel 4 through the fourth corner hole F4 and flows out of the second inter-plate channel 4 through the third corner hole F3. The refrigerant enters the first inter-plate channel 3 through the first corner hole F1 and flows out of the first inter-plate channel 3 through the second corner hole F2.

[0044] In some embodiments, the first corner hole F1 and the second corner hole F2 are distributed along one of the first sides 61, and the third corner hole F3 and the fourth corner hole F4 are distributed along the other first side 61. That is, in the first inter-plate channel 3 and the second inter-plate channel 4 on adjacent sides, the fluid in the inter-plate channels on both sides forms a parallel flow.

[0045] In other embodiments, the first corner hole F1 and the second corner hole F2 are diagonally distributed; the third corner hole F3 and the fourth corner hole F4 are diagonally distributed. That is, in the first inter-plate channel 3 and the second inter-plate channel 4 on adjacent sides, the fluid in the inter-plate channels on both sides forms a cross flow.

[0046] In the above embodiment, the orifice area of ​​the first corner hole F1 is smaller than that of any one of the second corner holes F2, the third corner hole F3, and the fourth corner hole F4, making it easier to distinguish. Furthermore, when the plate heat exchanger is used as an evaporator, the smaller orifice area of ​​the first corner hole F1 can act as a throttling device, increasing local resistance to improve the uniformity of refrigerant distribution in the inter-plate channels 3. Since the first corner hole F1 serves as the refrigerant inlet and has the lowest temperature, the risk of freezing at this location is higher than that of the other corner holes. Therefore, the contact area of ​​the first flush connection portion 1a and the second flush connection portion 2a is larger than the contact area of ​​any one of the flush connection portions around the second corner hole F2, the third corner hole F3, and the fourth corner hole F4.

[0047] When the fourth corner hole F4 serves as the inlet for the heat exchange medium, if the second inter-plate channel 4 has a flow channel at the corner of the fourth corner hole F4, the heat exchange medium, after entering through the fourth corner hole F4, will enter this flow channel and flow along the first side 61 closer to the fourth corner hole F4 towards the inter-plate channel, resulting in uneven distribution of the heat exchange medium. Therefore, to improve the uniformity of heat exchange medium distribution, this embodiment is designed as follows: Please refer again. Figure 4 and Figure 14The first heat exchange plate 1 includes a third flat joint 1b, which is located on the periphery of the fourth corner hole F4 of the first heat exchange plate 1. The second heat exchange plate 2 includes a fourth flat joint 2b, which is located on the periphery of the fourth corner hole F4 of the second heat exchange plate 2. The plate heat exchanger includes a first sealing part 7, which is located at the corner of the second interplate channel 4 on the periphery of the fourth corner hole F4. The first sealing part 7 seals the corner of the second interplate channel 4 on the periphery of the fourth corner hole F4. That is, the second interplate channel 4 is closed at the corner of the fourth corner hole F4. After the heat exchange medium enters through the fourth corner hole F4, due to the closure of the corner of this part, the heat exchange medium can be distributed more smoothly from the fourth corner hole F4 to the opposite side (i.e., the first side 61 which is farther away from the fourth corner hole F4), which is conducive to the uniform distribution of the heat exchange medium and improves the heat exchange effect with the refrigerant. The first sealing portion 7 includes a first protrusion 71. At least one of the third flat-joint portion 1b and the fourth flat-joint portion 2b has a first protrusion 71, which protrudes towards the second inter-plate channel 4. In some embodiments, one of the third flat-joint portion 1b and the fourth flat-joint portion 2b has a first protrusion 71; in other embodiments, both the third flat-joint portion 1b and the fourth flat-joint portion 2b have a first protrusion 71, and the first protrusion 71 is positioned corresponding to and connected to the first plate channel 4. In this embodiment, the first protrusion 71 is part of the heat exchange plate and is an integral structure with the heat exchange plate, being pressed and formed during the processing of the heat exchange plate. Of course, the first sealing portion 7 can also be an independent component before assembly and connection with the first heat exchange plate 1 and the second heat exchange plate 2. During the stacking of the heat exchange plates, it is assembled to the corner of the second inter-plate channel 4 around the fourth corner hole F4 for sealing. In addition, the connection through the first sealing part 7 can also improve the connection strength of the heat exchange plates on both sides of the second plate channel 4 at the fourth corner hole F4, and improve the pressure resistance of this part.

[0048] In the above embodiment, the third corner hole F3 and the first corner hole F1 are distributed along the length of the second side 62. Since the length of the second side 62 is shorter than the length of the first side 61, the third corner hole F3 is closer to the first corner hole F1. The first corner hole F1 serves as the refrigerant inlet, and its vicinity has a low temperature. If the heat exchange medium remains in this area for a long time, there is a risk of freezing. Furthermore, due to the small flow space at the corners of the second plate channel 4 around the third corner hole F3, slow flow or even stagnation is very likely to occur, leading to freezing. This can cause the heat exchange plates to expand due to the freezing of the heat exchange medium, resulting in problems such as detachment and cracking, ultimately causing the plate heat exchanger to fail. Therefore, this embodiment is designed as follows: Please refer again... Figure 4 and Figure 14The first heat exchange plate 1 includes a fifth flat joint 1c, which is located on the periphery of the third corner hole F3 of the first heat exchange plate 1. The second heat exchange plate 2 includes a sixth flat joint 2c, which is located on the periphery of the third corner hole F3 of the second heat exchange plate 2. The plate heat exchanger includes a second sealing part 8, which is located at the corner of the second inter-plate channel 4 on the periphery of the third corner hole F3. That is, the second sealing part 8 seals the corner of the second inter-plate channel 4 on the periphery of the third corner hole F3. In this way, the heat exchange medium in the second inter-plate channel 4 cannot enter the corner, and the heat exchange medium will not be affected by the stagnation and low temperature environment at the corner, which will lead to freezing. This further improves the reliability and durability of the plate heat exchanger. The second sealing portion 8 includes a second protrusion 81. At least one of the fifth flat-joint portion 1c and the sixth flat-joint portion 2c has a second protrusion 81, which protrudes toward the second inter-plate channel 4. In some embodiments, one of the fifth flat-joint portion 1c and the sixth flat-joint portion 2c has a second protrusion 81; in other embodiments, both the fifth flat-joint portion 1c and the sixth flat-joint portion 2c have second protrusions 81, and the second protrusions 81 are positioned correspondingly and connected to each other. In this embodiment, the second protrusion 81 is part of the heat exchange plate and is an integral structure with the heat exchange plate, being pressed and formed during the processing of the heat exchange plate. Of course, the second sealing portion 8 can also be an independent component before assembly and connection with the first heat exchange plate 1 and the second heat exchange plate 2. During the stacking of the heat exchange plates, it is assembled to the corner of the second inter-plate channel 4 around the triangular hole F3 for sealing.

[0049] Further, please refer to Figure 15 Since the second corner hole F2 is relatively far from the first corner hole F1, the heat exchange medium in the second interplate channel 4 at the position corresponding to the second corner hole F2 is less affected by the low temperature of the refrigerant at the position of the first corner hole F1, and the risk of freezing is low. In order to increase the flow area of ​​the heat exchange medium, improve the uniformity of distribution, and enhance the heat exchange effect, the second interplate channel 4 has a flow guide channel 4a. The flow guide channel 4a is located at the corner of the second interplate channel 4 around the second corner hole F2. In this way, the heat exchange medium can flow smoothly from the flow guide channel 4a to the side of the first side 61 that is far away from the fourth corner hole F4, thereby improving the heat exchange efficiency.

[0050] Please refer to section 2 again. Figure 5 , Figures 7 to 14 The plate heat exchanger includes a distribution section 9, which has a distribution hole 91. The distribution hole 91 connects the first corner hole F1 and the first inter-plate channel 3. That is, after the refrigerant passes through the first corner hole F1, it enters the first inter-plate channel 3 through the distribution hole 91, which increases the local resistance and ensures that the refrigerant flows evenly in each first inter-plate channel 3, so as to make full use of the heat exchange area of ​​the heat exchange plates.

[0051] In some embodiments, at least one of the first connecting portion flat joint 1a and the second connecting portion flat joint 2a includes a distributing portion 9. In this case, the distributing portion 9 is part of the heat exchange plate, integrally formed with the heat exchange plate, and is pressed during the production of the heat exchange plate, and then further processed to form the distributing portion 9 with distributing holes 91. It is possible that only one of the first connecting portion flat joint 1a and the second connecting portion flat joint 2a includes the distributing portion 9, for example, the first connecting portion flat joint 1a includes the distributing portion 9. Figure 10 As shown, the first connecting part flat joint 1a and the second connecting part flat joint 2a may both include a distribution part 9, which is not shown in the figure.

[0052] In other embodiments, the distribution section 9 is located between the first connecting section flat joint 1a and the second connecting section flat joint 2a. That is, the distribution section 9 and the heat exchange plates are independent components before assembly. During the stacking assembly process, the distribution section 9 is assembled to the corresponding position. The distribution section 9 is designed independently, or it can be omitted during the stacking assembly process. In this case, the plate heat exchanger can also be used as a condenser, which is not shown in the figure.

[0053] In the above embodiment, the first interplate channel 3 and the second interplate channel 4 are alternately distributed along the thickness direction of the plate heat exchanger. In order to achieve better heat exchange performance and lower pressure drop, the volume of the first interplate channel 3 is greater than or less than the volume of the second interplate channel 4. That is, the plate heat exchanger adopts an asymmetrical channel structure to form two interplate channels with different volumes, which can reduce the pressure drop without affecting the heat exchange performance.

[0054] Please refer to it again. Figure 1 In the above embodiments, the plate heat exchanger may also include an end plate 100, a connecting pipe 200, a bottom plate, etc. The end plate 100 is installed on the front of the first heat exchange plate, and the bottom plate is installed on the back of the last heat exchange plate. The end plate 100 is also equipped with a corresponding connecting pipe 200, and the inner cavity of the connecting pipe 200 is connected to the corresponding corner hole.

[0055] Some of the technical implementation methods described above can be combined or replaced.

[0056] The technical principles of the present invention have been described above in conjunction with specific embodiments. However, it should be noted that these descriptions are merely for explaining the principles of the present invention and should not be construed as limiting the scope of protection of the present invention in any way. Based on this explanation, those skilled in the art can conceive of other specific embodiments or equivalent substitutions of the present invention without creative effort, and all such embodiments will fall within the scope of protection of the present invention.

Claims

1. A plate heat exchanger, characterized in that: It includes multiple first heat exchange plates and multiple second heat exchange plates, which are stacked alternately along the thickness direction of the plate heat exchanger. The plate heat exchanger has a first inter-plate channel and a second inter-plate channel. The first inter-plate channel is located between the front side of the second heat exchange plate and the adjacent first heat exchange plate, and the second inter-plate channel is located between the back side of the second heat exchange plate and the adjacent first heat exchange plate. The first heat exchange plate and the second heat exchange plate have corresponding first corner holes, and the first corner holes are connected to the inter-plate channel; the first heat exchange plate has a first flat joint portion, and the first corner hole of the first heat exchange plate is located in the first flat joint portion; the second heat exchange plate has a second flat joint portion, and the first corner hole of the second heat exchange plate is located in the second flat joint portion; the front side of the second flat joint portion is spaced apart from the adjacent first flat joint portion; and the back side of the second flat joint portion is connected to the adjacent first flat joint portion. The first heat exchange plate and the second heat exchange plate have corresponding second corner holes, and the second corner holes are connected to the inter-plate channel; on a plane perpendicular to the thickness direction of the plate heat exchanger, the projected area of ​​at least one of the first flat joint and the second flat joint is greater than the projected area of ​​the flat joint of the first heat exchange plate on the periphery of the second corner hole, and the projected area of ​​at least one of the first flat joint and the second flat joint is greater than the projected area of ​​the flat joint of the second heat exchange plate on the periphery of the second corner hole. The plate heat exchanger includes at least one connecting portion, which connects the front side of the second flat joint portion and the adjacent first flat joint portion; The first heat exchange plate and the second heat exchange plate have corresponding fourth corner holes, which are connected to the second plate inter-plate channel. The plate heat exchanger includes a first sealing part, which is located at the corner of the second plate inter-plate channel around the fourth corner hole.

2. The plate heat exchanger according to claim 1, characterized in that: The connecting portion includes a boss, and at least one of the first flat portion and the second flat portion has the boss. The boss protrudes toward the first inter-plate channel and has a first contact surface with a width greater than or equal to 0.5 mm.

3. The plate heat exchanger according to claim 1, characterized in that: The connecting part includes a connecting block located in the first inter-plate channel. The connecting block is connected to the first flat joint and the second flat joint on both sides of the first inter-plate channel. The connecting block has a second contact surface with a width greater than or equal to 0.5 mm.

4. The plate heat exchanger according to any one of claims 1 to 3, characterized in that: The plate heat exchanger has an edge, and there is a flow gap between the connecting part and the edge.

5. The plate heat exchanger according to claim 4, characterized in that: The edging includes a first side and a second side. On the periphery of the first corner hole, the edge of the second inter-plate channel connects the first side and the second side. The area between the edge of the second inter-plate channel, the first side and the edge of the first corner hole is defined as the first area, and at least one connecting part is located in the first area; and / or, the area between the edge of the second inter-plate channel, the second side and the edge of the first corner hole is defined as the second area, and at least one connecting part is located in the second area. The edge of the second inter-plate channel is the boundary near the side of the second inter-plate channel where the first flat joint and the second flat joint meet.

6. The plate heat exchanger according to claim 5, characterized in that: The length of the first side is greater than the length of the second side, and the vertical distance from a point on the edge of the second inter-plate channel to the second side decreases along the line from the first side to the second side. The edge of the second inter-plate channel forms a first angle with the first side, and the angle of the first angle faces the first corner hole, wherein 10°≤ the first angle ≤ 30°; The edge of the second inter-plate channel forms a second included angle with the second side, and the angle of the second included angle faces the first corner hole, wherein 70°≤ the second included angle≤90°; The minimum distance from the edge of the second inter-plate channel to the edge of the first corner hole is greater than or equal to 2mm.

7. The plate heat exchanger according to claim 6, characterized in that: The first heat exchange plate and the second heat exchange plate are corrugated plates; the first heat exchange plate has a first corrugation that extends to the edge of the first flat joint; the second heat exchange plate has a second corrugation that extends to the edge of the second flat joint. The first heat exchange plate and the second heat exchange plate have corresponding third corner holes, and the third corner holes are connected to the inter-plate channel; The opening area of ​​the first corner hole is smaller than the opening area of ​​any one of the second, third, and fourth corner holes; The contact area of ​​the first flat joint and the second flat joint is greater than the contact area of ​​any one of the flat joints around the second corner hole, the third corner hole and the fourth corner hole.

8. The plate heat exchanger according to claim 6, characterized in that: The first inter-plate channel and the second inter-plate channel are alternately distributed along the thickness direction of the plate heat exchanger. The first inter-plate channel is used for refrigerant flow, and the first corner hole is used for refrigerant to flow into the first inter-plate channel. The second inter-plate channel is not connected to the first inter-plate channel. The volume of the first inter-plate channel is greater than or less than the volume of the second inter-plate channel.

9. The plate heat exchanger according to claim 7, characterized in that: The first corner hole and the second corner hole are diagonally distributed; the third corner hole and the fourth corner hole are diagonally distributed. The first heat exchange plate includes a third flat joint portion located on the periphery of the fourth corner hole of the first heat exchange plate; the second heat exchange plate includes a fourth flat joint portion located on the periphery of the fourth corner hole of the second heat exchange plate; the first sealing portion includes a first protrusion, at least one of the third flat joint portion and the fourth flat joint portion having the first protrusion, the first protrusion protruding toward the second interplate channel; The first heat exchange plate includes a fifth flat joint portion located on the periphery of the third corner hole of the first heat exchange plate. The second heat exchange plate includes a sixth flat joint portion located on the periphery of the third corner hole of the second heat exchange plate. The plate heat exchanger includes a second sealing portion located at the corner of the second interplate channel on the periphery of the third corner hole. The second sealing portion includes a second protrusion. At least one of the fifth flat joint portion and the sixth flat joint portion has the second protrusion, which protrudes toward the second interplate channel. The third corner hole and the first corner hole are distributed along the length direction of the second side.

10. The plate heat exchanger according to claim 9, characterized in that: The second inter-plate channel has a flow guiding channel, which is located at the corner of the second inter-plate channel around the second corner hole; The plate heat exchanger includes a distribution section, which has a distribution hole that connects a first corner hole and a first inter-plate channel. At least one of the first flat joint and the second flat joint includes the distribution portion, or the distribution portion is located between the first flat joint and the second flat joint.

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