Plate heat exchanger

Abstract

The utility model relates to heat exchanger technical field provides a plate heat exchanger, the utility model provides a plate heat exchanger includes a plurality of odd layer sheet and even layer sheet of alternative stacking, the odd layer sheet has a plurality of first corrugation protruding of lattice arrangement, the even layer sheet has a plurality of second corrugation protruding of lattice arrangement, the first corrugation protruding has first wave crest and first wave trough, the second corrugation protruding has second wave crest and second wave trough, the first wave crest with the second wave trough forms lattice contact, the two wave crest with first wave trough forms lattice contact. Heat exchange fluid is between the contact of wave crest and wave trough and is surrounded in the flow between, and the flow section is lattice type and contracts and expands, can promote fluid to form high -speed flow turbulent flow, and then improve the heat exchange efficiency of fluid.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, and in particular to a plate heat exchanger. Background Technology

[0002] A plate heat exchanger is a series of metal heat exchange plates with a certain corrugated structure stacked together, allowing hot and cold fluids to alternately pass between the plates to achieve heat exchange. That is, the fluids flowing on both sides of the plates are high-temperature fluid and low-temperature fluid, and the high-temperature fluid and low-temperature fluid exchange heat through the metal heat exchange plates.

[0003] In traditional plate heat exchangers, the upper and lower plates are usually assembled with crests to crests and troughs to troughs to keep the flow channel height between the plates constant. The fluid fluctuates periodically along the corrugation direction, resulting in low disturbance intensity, insufficient turbulence, and low heat exchange efficiency. Utility Model Content

[0004] This invention proposes a plate heat exchanger that aims to improve the heat exchange efficiency by changing the relative orientation of the corrugated structure of the upper and lower plates.

[0005] The plate heat exchanger provided by this utility model includes several alternately stacked odd-numbered and even-numbered plates. The odd-numbered plates have several first corrugated protrusions arranged in a dot matrix, and the even-numbered plates have several second corrugated protrusions arranged in a dot matrix. The first corrugated protrusions have a first peak and a first trough, and the second corrugated protrusions have a second peak and a second trough. The first peak and the second trough form a dot matrix contact, and the second peak and the first trough form a dot matrix contact.

[0006] In one embodiment, the first corrugated protrusion gradually contracts from one end toward the second corrugated protrusion to one end away from the second corrugated protrusion, and the second corrugated protrusion gradually contracts from one end toward the first corrugated protrusion to one end away from the first corrugated protrusion.

[0007] In one embodiment, the first corrugated protrusion and the second corrugated protrusion are respectively truncated cone-shaped.

[0008] In one embodiment, the angle of the first corrugated protrusion is a1, the angle of the second corrugated protrusion is a2, and 120°≤a1≤135°, 120°≤a2≤135°.

[0009] In one embodiment, the top surface of the first wave crest is a first flat surface, the bottom surface of the second wave trough is a second flat surface, and the first flat surface and the second flat surface are in contact; the top surface of the second wave crest is a third flat surface, the bottom surface of the first wave trough is a fourth flat surface, and the third flat surface and the fourth flat surface are in contact.

[0010] In one embodiment, the vertical distance between the first flat surface and the fourth flat surface is h1, the vertical distance between the second flat surface and the third flat surface is h2, the connection width between the first flat surface and the second flat surface is W1, the connection width between the third flat surface and the fourth flat surface is W2, 1 / 5≤W1 / h1≤1 / 2, 1 / 5≤W2 / h2≤1 / 2.

[0011] In one embodiment, adjacent rows of the first corrugated protrusions are staggered, and adjacent rows of the second corrugated protrusions are staggered.

[0012] In one embodiment, the odd-numbered and even-numbered layers each include a base plate and a surrounding plate integrally connected to the base plate. The base plate and the surrounding plate together form a receiving groove. A first corrugated protrusion is formed on the base plate of the odd-numbered layer, and a second corrugated protrusion is formed on the base plate of the even-numbered layer. A flange is provided at the end of the surrounding plate away from the base plate. The flange is disposed opposite to the base plate. The side plate of the upper layer is at least partially disposed in the receiving groove of the lower layer. The flanges of each layer are stacked and positioned, and the recess depth of the receiving groove of the upper layer is less than the recess depth of the receiving groove of the lower layer.

[0013] In one embodiment, the cross-sectional area of ​​the receiving groove gradually decreases from the opening to the bottom.

[0014] In one embodiment, an inter-plate flow channel is formed between the odd-numbered plate layers and the even-numbered plate layers. The plate heat exchanger also has a first inlet channel and a first outlet channel communicating with the inter-plate flow channel of the odd-numbered layers, and a second inlet channel and a second outlet channel communicating with the inter-plate flow channel of the even-numbered layers. The first inlet channel and the first outlet channel are respectively located at opposite ends of the plate heat exchanger. The second inlet channel and the first outlet channel are located at the same end of the plate heat exchanger. The second outlet channel and the first inlet channel are located at the same end of the plate heat exchanger.

[0015] In this plate heat exchanger, both the first and second corrugated protrusions are arranged in a lattice pattern. The first corrugated protrusion has a first peak and a first trough, and the second corrugated protrusion has a second peak and a second trough. The first peak and the second trough are in contact and adhere to each other, thus forming a lattice contact between the first peak and the second trough, and between the second peak and the first trough. During the heat exchange process, the heat exchange fluid flows in a swirling pattern between the contact points of the peaks and troughs. The flow cross-section exhibits a lattice-like contraction and expansion, which promotes high-speed turbulent flow and thus improves the heat exchange efficiency of the fluid. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is an exploded view of an embodiment of the plate heat exchanger provided by this utility model; Figure 2 This is a schematic diagram of an embodiment of the plate heat exchanger provided by this utility model after assembly; Figure 3 yes Figure 2 Cross-sectional view of AA in the middle; Figure 4 yes Figure 2 Cross-sectional view of BB in the middle; Figure 5 This is a partial enlarged cross-sectional view of an embodiment of the plate heat exchanger provided by this utility model.

[0018] Explanation of reference numerals in the attached figures: 11. Odd-numbered layer plate; 111. First corrugated protrusion; 111a. First crest; 111b. First trough; 12. Even-numbered layer plate; 121. Second corrugated protrusion; 121a. Second crest; 121b. Second trough; 13. Base plate; 14. Enclosure plate; 15. Flange; 16. First inlet pipe; 161. First inlet channel; 17. First outlet pipe; 171. First outlet channel; 18. Second inlet pipe; 181. Second inlet channel; 19. Second outlet pipe; 191. Second outlet channel; 21. First fluid; 22. Second fluid. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0020] It should be noted that the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to direct setup or connection, or indirect setup or connection through centered components or centered structures.

[0021] Furthermore, in embodiments of this utility model, terms such as "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are used to indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, or in a conventional placement or usage state. These terms are merely for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the structure, feature, device, or element referred to must have a specific orientation or positional relationship, nor that it must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In the description of this utility model, unless otherwise stated, "multiple" means two or more.

[0022] The various specific technical features and embodiments described in the detailed embodiments can be combined in any suitable manner without contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the various specific technical features / embodiments in this utility model will not be described separately.

[0023] This invention proposes a plate heat exchanger that aims to improve the heat exchange efficiency by changing the relative orientation of the corrugated structure of the upper and lower plates.

[0024] Reference Figures 1 to 5 An embodiment of the plate heat exchanger of this utility model includes several alternately stacked odd-numbered layers of plates 11 and even-numbered layers of plates 12. The odd-numbered layers of plates 11 have several first corrugated protrusions 111 arranged in a lattice, and the even-numbered layers of plates 12 have several second corrugated protrusions 121 arranged in a lattice. The first corrugated protrusions 111 have a first peak 111a and a first trough 111b, and the second corrugated protrusions 121 have a second peak 121a and a second trough 121b. The first peak 111a and the second trough 121b form a lattice contact, and the second peak 121a and the first trough 111b form a lattice contact.

[0025] Specifically, the embodiment of this plate heat exchanger includes several odd-numbered layers of plates 11 and even-numbered layers of plates 12 formed by metal stamping. The stacking direction of the odd-numbered layers of plates 11 and even-numbered layers of plates 12 is the height direction of the plate heat exchanger. The odd-numbered layers of plates 11 have a first corrugated structure, which is formed by several first corrugated protrusions 111. The even-numbered layers of plates 12 have a second corrugated structure, which is formed by several second corrugated protrusions 121. In traditional plate heat exchangers, the corrugated structures in the upper and lower layers of plates are usually arranged in a strip shape, and the upper and lower layers of plates are usually assembled in a way that is crest to crest and trough to trough. In this assembly method, the height of the flow channel between the plates is constant, and the fluid undulates periodically along the corrugation direction, resulting in low disturbance intensity, insufficient turbulence, and low heat exchange efficiency. Unlike other plate heat exchangers, in this invention, the first corrugated protrusion 111 and the second corrugated protrusion 121 are both arranged in a lattice pattern. The first corrugated protrusion 111 has a first peak 111a and a first trough 111b, and the second corrugated protrusion 121 has a second peak 121a and a second trough 121b. The first peak 111a and the second trough 121b are in contact and adhere to each other, thus forming a lattice contact between the first peak 111a and the second trough 121b, and between the second peak 121a and the first trough 111b. During the heat exchange process, the heat exchange fluid flows in a swirling pattern between the contact points of the peaks and troughs, and the flow cross section exhibits a lattice pattern of contraction and expansion, which can promote the formation of high-speed turbulent flow, thereby improving the heat exchange efficiency of the fluid.

[0026] In practical applications, the first corrugated protrusion 111 and the second corrugated protrusion 121 can be conical. The first corrugated protrusion 111 gradually tapers from the end facing the second corrugated protrusion 121 to the end away from the second corrugated protrusion 121, and the second corrugated protrusion 121 gradually tapers from the end facing the first corrugated protrusion 111 to the end away from the first corrugated protrusion 111. With the first corrugated protrusion 111 and the second corrugated protrusion 121 configured as tapered conical surfaces, the fluid flows downwards along the cross-section after hitting the apex of the cone, changing direction and resulting in higher turbulence intensity and better heat transfer.

[0027] Furthermore, the first corrugated protrusion 111 and the second corrugated protrusion 121 can be in the shape of a frustum, with the bottom surface of the frustum gradually contracting to the top surface. The height of the frustum is linearly related to the radius of the bottom surface. The flow channel cross section contracts and expands linearly along the flow direction, resulting in a relatively small local loss coefficient.

[0028] Reference Figure 5The angle of the first corrugated protrusion 111 is defined as a1, and the angle of the second corrugated protrusion 121 is defined as a2. In practical applications, 120°≤a1≤135° and 120°≤a2≤135°. The angle between the first corrugated protrusion 111 and the second corrugated protrusion 121 being between 120° and 135° can reduce heat loss while ensuring turbulence intensity.

[0029] At this point, the top surface of the first wave crest 111a is a first flat surface, and the bottom surface of the second wave trough 121b is a second flat surface, with the first flat surface and the second flat surface in close contact. Similarly, the top surface of the second wave crest 121a is a third flat surface, and the bottom surface of the first wave trough 111b is a fourth flat surface, with the third flat surface and the fourth flat surface in close contact. Specifically, the first flat surface and the second flat surface, as well as the third flat surface and the fourth flat surface, can be fixed by welding or bonding. The first corrugated structure and the second corrugated structure are connected by flat surfaces, which can increase the contact area between the odd-numbered plate layers 11 and the even-numbered plate layers 12, ensure the connection strength between the odd-numbered plate layers 11 and the even-numbered plate layers 12, and thus improve the overall stability of the plate heat exchanger.

[0030] Reference Figure 5 The vertical distance between the first and fourth straight surfaces is defined as h1, i.e., the vertical distance between the top surface of the first crest 111a and the bottom surface of the first trough 111b is h1. The vertical distance between the second and third straight surfaces is defined as h2, i.e., the vertical distance between the bottom surface of the second trough 121b and the top surface of the second crest 121a is h2. The minimum contact width between the first and second straight surfaces is W1, and the minimum contact width between the third and fourth straight surfaces is W2. 1 / 5 ≤ W1 / h1 ≤ 1 / 2, 1 / 5 ≤ W2 / h2 ≤ 1 / 2. Setting W1 / h1 and W2 / h2 in the range of 1 / 5 to 1 / 2 can avoid the problem of insufficient connection strength due to insufficient contact between crests and troughs, and at the same time avoid the problem of reduced flow channel space between plates due to excessive contact, which would affect heat transfer performance.

[0031] In practical applications, adjacent rows of first corrugated protrusions 111 can be staggered, and adjacent rows of second corrugated protrusions 121 can also be staggered. At this time, the contact points of the first corrugated protrusions 111 and the second corrugated protrusions 121 form a mesh, and the heat exchange fluid can further improve the turbulence effect by circulating between the contact points, thereby improving the heat exchange efficiency.

[0032] Reference Figure 3 or Figure 4The odd-numbered layer plates 11 and the even-numbered layer plates 12 each include a base plate 13 and a surrounding plate 14 that is integrally connected to the base plate 13 and is disposed around the base plate 13. The base plate 13 and the surrounding plate 14 form a receiving groove. A first corrugated protrusion 111 is formed on the base plate 13 of the odd-numbered layer plate 11, and a second corrugated protrusion 121 is formed on the base plate 13 of the even-numbered layer plate 12. A flange 15 is provided at the end of the surrounding plate 14 away from the base plate 13. The flange 15 is disposed opposite to the base plate 13. The side plate of the upper layer plate is at least partially disposed in the receiving groove of the lower layer plate. The flanges 15 of each layer plate are stacked and limited, and the recess depth of the receiving groove of the upper layer plate is less than the recess depth of the receiving groove of the lower layer plate.

[0033] Specifically, each plate is bowl-shaped overall, and the base plate 13, the surrounding plate 14, and the flange 15 can be integrally formed by stamping. The base plate 13 and the surrounding plate 14 form a receiving groove for accommodating the upper layer plate. The lower layer plate can serve as a nestable shell for the upper layer plate, and the plates can be automatically aligned without precise positioning on all four sides when stacked. When the plates are nested to their limit, the flanges 15 of each plate are pressed tightly together, thus limiting the position of each plate. At the same time, the flanges 15 can also share the clamping force between the plates, preventing the corrugated protrusions from collapsing under the pressure.

[0034] The cross-sectional area of ​​the receiving groove gradually decreases from the opening to the bottom. In other words, the receiving groove is conical, with the largest opening at the opening and the smallest opening at the bottom. Of course, the surrounding plate 14 should not be excessively tilted; an angle between 1° and 3° is preferable. The conical groove provides a progressive guide, automatically correcting coaxiality when the upper plate is inserted into the receiving groove of the lower plate, eliminating the need for positioning rods or manual fine-tuning.

[0035] An inter-plate flow channel is formed between the odd-numbered plates 11 and the even-numbered plates 12. The plate heat exchanger also has a first inlet channel 161 and a first outlet channel 171 communicating with the inter-plate flow channel of the odd-numbered plates, and a second inlet channel 181 and a second outlet channel 191 communicating with the inter-plate flow channel of the even-numbered plates. Figure 3 and Figure 4 As shown, the first inlet channel 161 and the first outlet channel 171 are respectively located at opposite ends of the plate heat exchanger. The second inlet channel 181 and the first outlet channel 171 are located at the same end of the plate heat exchanger, and the second outlet channel 191 and the first inlet channel 161 are located at the same end of the plate heat exchanger. That is, the inlet and outlet directions of the odd-numbered plate channels are opposite to those of the even-numbered plate channels. For example, when the odd-numbered plate channels are left-inlet and right-outlet, the even-numbered plate channels are right-inlet and left-outlet; when the odd-numbered plate channels are right-inlet and left-outlet, the even-numbered plate channels are left-inlet and right-outlet. The design of the inlet and outlet directions of the odd-numbered plate channels being opposite to those of the even-numbered plate channels enables convective heat transfer.

[0036] The process is illustrated by introducing a first fluid 21 into the odd-numbered inter-plate channels and a second fluid 22 into the even-numbered inter-plate channels. The first fluid 21 and the second fluid 22 can be liquids or gases. One of the first fluid 21 and the second fluid 22 can be a relatively high-temperature fluid, while the other is a relatively low-temperature fluid. The first fluid 21 and the second fluid 22, with a temperature difference, flow on opposite sides of the plates to exchange heat. See details... Figure 1 , Figure 3 and Figure 4 The first fluid 21 enters the first inlet channel 161 and branches from the first inlet channel 161 into each odd-numbered inter-layer channel. The fluid in the odd-numbered inter-layer channels flows back and forth between the contact points between the crests and troughs, and then flows out through the first outlet channel 171. The second fluid 22 enters the second inlet channel 181 and branches from the second inlet channel 181 into each even-numbered inter-layer channel. The fluid in the even-numbered inter-layer channels flows back and forth between the contact points between the crests and troughs, and then flows out through the second outlet channel 191.

[0037] Furthermore, the first inlet channel 161 and the first outlet channel 171 can be arranged diagonally, as can the second inlet channel 181 and the second outlet channel 191. Specifically, the base plate 13 of the plate is square, the first inlet channel 161 and the first outlet channel 171 are connected to the flow channels between odd-numbered layers, and the second inlet channel 181 and the second outlet channel 191 are connected to the flow channels between even-numbered layers. The first inlet channel 161 and the first outlet channel 171 are located at opposite ends of the same diagonal, and the second inlet channel 181 and the second outlet channel 191 are located at opposite ends of another diagonal. This extends the heat exchange path of the first fluid 21 and the second fluid 22, allowing for sufficient heat exchange between the two fluids.

[0038] To isolate the inlet and outlet water flow paths of the odd-numbered inter-plate channels from those of the even-numbered inter-plate channels, embodiments of this plate heat exchanger may further include a first inlet pipe 16 and a first outlet pipe 17. The first inlet pipe 16 and the first outlet pipe 17 extend from the top plate to the bottom inter-plate channel, respectively. The first inlet pipe 16 forms a first inlet channel 161, and the first outlet pipe 17 forms a first outlet channel 171. The side wall of the first inlet pipe 16 is provided with a first through-hole to connect the flow path of the first inlet pipe 16 and the odd-numbered inter-plate channels. The side wall of the first outlet pipe 17 is provided with a second through-hole to connect the flow path of the odd-numbered inter-plate channels and the flow path of the first outlet pipe 17. Similarly, the plate heat exchanger also includes a second inlet pipe 18 and a second outlet pipe 19. The second inlet pipe 18 and the second outlet pipe 19 extend from the top plate to the flow channel between the even-numbered plates at the bottom. The second inlet pipe 18 forms a second inlet channel 181, and the second outlet pipe 19 forms a second outlet channel 191. The side wall of the second inlet pipe 18 is provided with a third water outlet to connect the flow channel of the second inlet pipe 18 and the flow channel between the even-numbered plates. The side wall of the second outlet pipe 19 is provided with a fourth water outlet to connect the flow channel between the even-numbered plates and the flow channel of the second outlet pipe 19.

[0039] Specifically, the bottom plate 13 of the corresponding plate is provided with corner holes for the water inlet pipe and the water outlet pipe to pass through. The first water inlet pipe 16 and the first water outlet pipe 17 extend from the top plate through the corresponding corner holes in a direction perpendicular to the bottom plate 13 to the bottom inter-plate flow channel, that is, the first inter-plate flow channel from bottom to top, and the first water inlet pipe 16 and the second water inlet pipe 18 are diagonally arranged. The first water inlet pipe 16 forms a first water inlet channel 161, and the first water outlet pipe 17 forms a first water outlet channel 171. The side wall of the first water inlet pipe 16 is provided with a plurality of first water outlets, the number of which is the same as the number of odd-numbered inter-plate flow channels, and one first water outlet is connected to one odd-numbered inter-plate flow channel; the side wall of the first water outlet pipe 17 is provided with a plurality of second water outlets, the number of which is the same as the number of odd-numbered inter-plate flow channels, and one second water outlet is connected to one odd-numbered inter-plate flow channel. Similarly, the second inlet pipe 18 and the second outlet pipe 19 extend from the top plate through the corresponding corner holes in a direction perpendicular to the bottom plate 13 to the even-numbered inter-plate flow channel at the bottom, i.e., the second inter-plate flow channel from bottom to top, and the second inlet pipe 18 and the second outlet pipe 19 are diagonally arranged. The second inlet pipe 18 forms a second inlet channel 181, and the second outlet pipe 19 forms a second outlet channel 191. The side wall of the second inlet pipe 18 is provided with a number of third water outlets, the number of which is the same as the number of even-numbered inter-plate flow channels, and one third water outlet is connected to one even-numbered inter-plate flow channel; the side wall of the second outlet pipe 19 is provided with a number of fourth water outlets, the number of which is the same as the number of even-numbered inter-plate flow channels, and one fourth water outlet is connected to one even-numbered inter-plate flow channel.

[0040] At this time, the flow paths of the first fluid 21 and the second fluid 22 are as follows: the first fluid 21 enters the first inlet pipe 16, and then flows into the corresponding odd-numbered inter-plate channel through the first outlet. The first fluid 21 in the odd-numbered inter-plate channel flows obliquely along the corrugated structure of the corresponding plate. When it reaches the second outlet, it flows through the second outlet into the first outlet pipe 17. The first fluid 21 in each odd-numbered inter-plate channel is discharged from the first outlet pipe 17. The second fluid 22 enters the second inlet pipe 18, and then flows into the corresponding even-numbered inter-plate channel through the third outlet. The second fluid 22 in the even-numbered inter-plate channel flows obliquely along the corrugated structure of the corresponding plate. When it reaches the fourth outlet, it flows through the fourth outlet into the second outlet pipe 19. The second fluid 22 in each even-numbered inter-plate channel is discharged from the second outlet pipe 19.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A plate heat exchanger, characterized in that, It includes several alternately stacked odd-numbered and even-numbered layers of plates. The odd-numbered layers have several first corrugated protrusions arranged in a lattice, and the even-numbered layers have several second corrugated protrusions arranged in a lattice. The first corrugated protrusions have a first peak and a first trough, and the second corrugated protrusions have a second peak and a second trough. The first peak and the second trough form a lattice contact, and the second peak and the first trough form a lattice contact.

2. The plate heat exchanger as described in claim 1, characterized in that, The first corrugated protrusion gradually contracts from the end facing the second corrugated protrusion to the end away from the second corrugated protrusion, and the second corrugated protrusion gradually contracts from the end facing the first corrugated protrusion to the end away from the first corrugated protrusion.

3. The plate heat exchanger as described in claim 2, characterized in that, The first corrugated protrusion and the second corrugated protrusion are respectively truncated cone-shaped.

4. The plate heat exchanger as described in claim 3, characterized in that, The angle of the first corrugated protrusion is a1, and the angle of the second corrugated protrusion is a2, where 120°≤a1≤135° and 120°≤a2≤135°.

5. The plate heat exchanger as described in claim 3, characterized in that, The top surface of the first wave crest is a first flat surface, and the bottom surface of the second wave trough is a second flat surface. The first flat surface and the second flat surface are in close contact. The top surface of the second peak is a third flat surface, and the bottom surface of the first trough is a fourth flat surface. The third flat surface and the fourth flat surface are in close contact.

6. The plate heat exchanger as described in claim 5, characterized in that, The vertical distance between the first flat surface and the fourth flat surface is h1, the vertical distance between the second flat surface and the third flat surface is h2, the connection width between the first flat surface and the second flat surface is W1, the connection width between the third flat surface and the fourth flat surface is W2, 1 / 5≤W1 / h1≤1 / 2, 1 / 5≤W2 / h2≤1 / 2.

7. The plate heat exchanger as described in any one of claims 1 to 6, characterized in that, The first corrugated protrusions in two adjacent rows are staggered, and the second corrugated protrusions in two adjacent rows are staggered.

8. The plate heat exchanger as described in any one of claims 1 to 6, characterized in that, The odd-numbered and even-numbered layers each include a base plate and a surrounding plate integrally connected to the base plate. The base plate and the surrounding plate together form a receiving groove. A first corrugated protrusion is formed on the base plate of the odd-numbered layer, and a second corrugated protrusion is formed on the base plate of the even-numbered layer. A flange is provided at the end of the surrounding plate away from the base plate. The flange is disposed opposite to the base plate. The side plate of the upper layer is at least partially disposed in the receiving groove of the lower layer. The flanges of each layer are stacked and limited, and the recess depth of the receiving groove of the upper layer is less than the recess depth of the receiving groove of the lower layer.

9. The plate heat exchanger as described in claim 8, characterized in that, The cross-sectional area of ​​the receiving groove gradually decreases from the opening to the bottom.

10. The plate heat exchanger according to any one of claims 1 to 6, characterized in that, The odd-numbered plates and the even-numbered plates form inter-plate flow channels. The plate heat exchanger also has a first inlet channel and a first outlet channel communicating with the inter-plate flow channels of the odd-numbered plates, and a second inlet channel and a second outlet channel communicating with the inter-plate flow channels of the even-numbered plates. The first inlet channel and the first outlet channel are respectively located at opposite ends of the plate heat exchanger. The second inlet channel and the first outlet channel are located at the same end of the plate heat exchanger. The second outlet channel and the first inlet channel are located at the same end of the plate heat exchanger.

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