Micro-channel steam condensation heat exchange plate

Abstract

The invention belongs to the technical field of thermoelectric conversion, and discloses a micro-channel steam condensation heat exchange plate which comprises a flow channel plate and a sealing plate installed on the flow channel plate, one face of the flow channel plate is sealed, the other face of the flow channel plate is provided with a hollow medium flow channel, and the hollow medium flow channel comprises an inlet flow distribution section, a middle straight-through flow channel section and an outlet flow distribution section which are sequentially connected. The inlet flow distribution section and the middle straight-through flow channel section are in vertical steering, the middle straight-through flow channel section and the outlet flow distribution section are in vertical steering, and the inlet flow distribution section is provided with an inlet flow channel partition plate for first-stage flow distribution. A flow guide structure is arranged at the vertical turning position between the inlet flow distribution section and the middle straight-through flow channel section for secondary flow distribution. The heat exchange plate has the advantages of being uniform in surface temperature distribution, reliable in pressure bearing capacity and high in heat exchange efficiency.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thermoelectric conversion, and particularly relates to a micro-channel steam condensation heat exchange plate. BACKGROUND

[0002] The existing industrial application micro-channel heat exchange plate is mostly for single-phase fluid medium, and the uniformity of fluid flow distribution in each channel is not required in the design, so that the temperature distribution of the outer wall surface of the heat exchange plate is not uniform enough, and the heat exchange efficiency of the heat exchange plate during operation is reduced.

[0003] At present, in the field of thermoelectric conversion, in order to improve the overall conversion efficiency of the thermoelectric conversion device, and to improve the energy weight ratio and the energy volume ratio, higher requirements are put forward for the compactness of the micro-channel heat exchange plate design structure applied to the cold and hot source end of the thermoelectric device, the uniformity of the heat exchange surface temperature distribution, and the heat exchange efficiency of the heat exchange plate.

[0004] In order to improve the uniformity of the surface temperature distribution of the heat exchange plate, the flow uniformity space header structure of the heat exchange plate inlet is usually designed to make the flow rates of the fluids entering each micro-channel flow passage after uniformization similar, and the flow and heat exchange process is more uniform. However, for steam as a heat source, the steam density entering the heat exchange plate is small and the flow rate is high under the same mass flow rate, and after condensation into water, the density increases and the flow rate is greatly reduced. It is difficult to design a heat exchange plate structure with reasonable inlet and outlet flow rates. At the same time, the traditional inlet flow uniformity space structure needs a larger flow uniformity space and a more complex fluid guiding rib plate structure for steam medium with high flow rate, and the wall surface pressure bearing capacity of the heat exchange plate inlet position is also higher, and the design difficulty is also greater. SUMMARY

[0005] The present application aims to overcome the defects of the prior art, and provides a micro-channel steam condensation heat exchange plate which can not only fully utilize the latent heat of phase change in the process of steam condensing into water, but also utilize the characteristics of efficient heat transfer and uniform and stable saturation temperature in the condensation process. The heat exchange plate has good internal micro-channel flow distribution uniformity and heat exchange plate surface temperature distribution uniformity, and has good heat exchange efficiency and pressure bearing capacity.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] The micro-channel steam condensation heat exchange plate comprises a flow channel plate and a sealing plate installed thereon, one side of the flow channel plate is closed, and the other side is provided with a hollow medium flow channel, the hollow medium flow channel comprises an inlet flow distribution section, an intermediate straight flow channel section and an outlet flow distribution section connected in sequence, the inlet flow distribution section and the intermediate straight flow channel section are vertically turned, the intermediate straight flow channel section and the outlet flow distribution section are vertically turned, the inlet flow distribution section is provided with an inlet flow channel partition plate for primary flow distribution, and a flow guide structure is arranged at the vertical turning position between the inlet flow distribution section and the intermediate straight flow channel section for secondary flow distribution.

[0008] In some embodiments, the inlet of the inlet flow distribution section and the outlet of the outlet flow distribution section are arranged at diagonal positions of the rectangular heat exchange plate to form a Z-shaped flow channel structure.

[0009] In some embodiments, the inlet of the inlet flow distribution section and the outlet of the outlet flow distribution section are arranged at two ends of the same side of the rectangular heat exchange plate to form a C-shaped flow channel structure.

[0010] In some embodiments, the intermediate straight flow channel section has a plurality of straight flow channels, and each straight flow channel is a cross-section flow channel with equal width and depth.

[0011] In some embodiments, the cross-section flow channel is a rectangular cross-section flow channel.

[0012] In some embodiments, the inlet and outlet of each straight flow channel are provided with a flow guide structure.

[0013] In some embodiments, the flow guide structure is provided with a circular arc surface structure to reduce local resistance, and the inlet and outlet widths of different straight flow channels are designed according to the length of the corresponding straight flow channel medium flow process to ensure that the flow resistances of all channels are similar.

[0014] In some embodiments, the flow channel plate and the sealing plate are stacked and assembled after being processed respectively, and are formed into an integrated structure through diffusion welding.

[0015] In some embodiments, the flow channel plate and the sealing plate are integrally manufactured.

[0016] In some embodiments, the width of the heat exchange plate is L1, the length of the heat exchange plate is L2, the thickness of the heat exchange plate is H, the depth of the flow channel is h, the outer wall thickness of the heat exchange plate is t1, the thickness of the flow channel wall and the flow channel partition plate in the intermediate straight flow channel section of the heat exchange plate is t2, the total width of the inlet flow channel of the inlet flow distribution section of the heat exchange plate is A, and the total width of the outlet flow channel of the outlet flow distribution section of the heat exchange plate is B.

[0017] In some embodiments, the number of flow channels separated by the flow channel separation plate after the separation of the heat exchange plate inlet and outlet is n, the number of middle straight flow channels in the heat exchange plate is m, the widths of the first to the nth inlet sub-flow channels are a1-a n , the widths of the first to the nth outlet sub-flow channels are b1-b n , the width of the middle straight flow channel section is c, and the minimum flow channel widths after the flow guide structure is arranged at the inlet and outlet of the middle straight flow channel of the heat exchange plate are d1-d m .

[0018] Compared with the prior art, the micro-channel steam condensation heat exchange plate provided by the application has the following beneficial effects:

[0019] The steam condensation heat exchange plate provided by the application fully utilizes the characteristics of high energy density and isothermal heat release of latent heat released in the phase change process of water vapor condensing into water, and has the advantages of uniform surface temperature distribution of the heat exchange plate, reliable pressure-bearing capacity, and high heat exchange efficiency of the heat exchange plate by reasonably designing the inlet and outlet flow distribution structure of the heat exchange plate.

[0020] The application is designed for a steam heat source, and a two-stage flow distribution structure is adopted for the steam inlet flow channel, so that the steam flow has two uniform distribution processes before entering the middle straight flow channel of the heat exchange plate. Through reasonable design of the key size of the flow channel, the fluid resistance of each middle straight flow channel is similar, and the flow is basically the same. Combined with the isothermal heat release characteristics of the steam condensation process, the problem of uneven wall surface temperature distribution of the same type of heat exchange plate is solved, and the overall heat exchange efficiency of the heat exchange plate is improved.

[0021] The heat exchange plate of the application is symmetrical in the thickness direction, and the metal wall thicknesses on both sides of the flow channel are the same, so that the heat exchange functions of the upper and lower surfaces of the heat exchange plate can be realized at the same time. The inlet and outlet of the heat exchange plate can be arranged at the diagonal positions of the rectangular heat exchange plate to form a “Z”-shaped flow channel structure, or can be arranged at the two ends of the same side of the rectangular heat exchange plate to form a “C”-shaped flow channel structure.

[0022] The heat exchange plate of the application adopts a large number of separation plates to form a compact flow distribution structure, which avoids the problem of insufficient pressure-bearing capacity caused by the use of traditional large uniform flow space header structures in the plate. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the application, the following will briefly introduce the drawings needed to be used in the technical description.

[0024] Figure 1 is a sectional view of the micro-channel steam condensation heat exchange plate provided by the application;

[0025] Figure 2 is a structural schematic view of the flow channel plate provided by the application;

[0026] Figure 3 Inlet cross-section view of the flow channel plate provided in the present application;

[0027] Figure 4 Outlet cross-section view of the flow channel plate provided in the present application.

[0028] Explanation of reference numerals:

[0029] 1. flow channel plate; 2. sealing plate;

[0030] 101. inlet flow distribution section; 102. intermediate straight flow channel section; 103. outlet flow distribution section; 104. flow channel partition plate; 105. flow guide structure;

[0031] H. thickness of the micro-channel steam condensation heat exchange plate; h. depth of the flow channel in the heat exchange plate;

[0032] L1. width of the heat exchange plate; L2. length of the heat exchange plate;

[0033] A. total width of the inlet flow channel of the inlet flow distribution section of the heat exchange plate; B. total width of the outlet flow channel of the outlet flow distribution section of the heat exchange plate;

[0034] t1. thickness of the outer wall of the heat exchange plate; t2. thickness of the flow channel wall of the intermediate straight flow channel section of the heat exchange plate and thickness of the flow channel partition plate 104;

[0035] n. number of sub-channels of the heat exchange plate after being partitioned by the flow channel partition plate at the inlet and outlet; m. number of intermediate straight flow channels of the heat exchange plate;

[0036] a1-a n n. width of the first to nth inlet sub-channels;

[0037] b1-b n n. width of the first to nth outlet sub-channels;

[0038] c. width of the m equal-width intermediate straight flow channels in the intermediate straight flow channel section of the heat exchange plate;

[0039] d1-d m n. minimum width of the flow channels after the flow guide structure is arranged at the inlet and outlet of the m intermediate straight flow channels of the heat exchange plate. DETAILED DESCRIPTION

[0040] Further details will be described in the following through specific embodiments.

[0041] As Figures 1 to 4As shown, the application provides a micro-channel steam condensation heat exchange plate, which comprises a flow channel plate 1 and a sealing plate 2. The application is suitable for use in the hot end heat plate of a thermoelectric conversion device with steam as a heat source. Under the condition that the temperature resistance and pressure resistance meet the steam operation parameters, the stability of the device heat source is ensured, and the internal flow field uniformity of the heat exchange plate and the heat exchange surface thermal uniformity of the heat exchange plate are good.

[0042] Optionally, the flow channel plate 1 and the sealing plate 2 are stacked and assembled after being processed respectively, and are formed into an integrated structure by diffusion welding.

[0043] Optionally, the flow channel plate 1 and the sealing plate 2 are integrally manufactured by additive manufacturing technology such as 3D printing. That is, the flow channel plate 1 and the sealing plate 2 are integrally manufactured by additive manufacturing technology such as 3D printing as a continuous whole part with a fitted surface, and directly form a metal sheet with a hollow medium flow channel structure.

[0044] As shown in Figure 1 and Figure 2 , the flow channel plate 1 is a rectangular metal sheet with one closed surface and the other surface processed with a hollow medium flow channel. The closed surface has a certain thickness for pressure resistance, and the thickness is equal to the difference between the thickness of the flow channel plate 1 and the processing depth h of the flow channel. The hollow medium flow channel is divided into an inlet flow distribution section 101, an intermediate straight flow channel section 102, and an outlet flow distribution section 103 according to the order of fluid flow in the plate, and the processing depth of each section is the same depth h and less than the thickness of the flow channel plate 1.

[0045] The sealing plate 2 is a rectangular metal sheet with the same length and width as the flow channel plate 1, and is used to close the surface of the flow channel plate 1 with the medium flow channel. The thickness of the sealing plate 2 is the same as the thickness of the closed surface of the flow channel plate 1.

[0046] The flow channel plate 1 and the sealing plate 2 are aligned and then diffusion welded to weld the fitted surface and form a closed hollow medium flow channel.

[0047] The inlet medium of the hollow medium flow channel is water vapor, and the outlet medium is liquid water after steam condensation. The inlet and outlet can be arranged at the diagonal position of the rectangular heat exchange plate to form a "Z" shaped flow channel structure, or can be arranged at the two ends of the same side of the rectangular heat exchange plate to form a "C" shaped flow channel structure. The metal wall thickness of the upper and lower surfaces of the hollow medium flow channel of the heat exchange plate is the same (H-h) / 2, and both can be used for heat exchange.

[0048] As shown in Figure 2As shown, steam flows in through the inlet of the hollow medium flow channel in the heat exchange plate composed of flow channel plate 1 and sealing plate 2. After passing through the inlet flow distribution section 101 of the hollow medium flow channel, the steam medium is distributed into a total of n groups of inlet branch flow channels. Then, after being vertically turned in each inlet branch flow channel, it is distributed into a total of m straight flow channels through a secondary grouping method. The straight flow channels corresponding to all groups of inlet branches are arranged in parallel to form the intermediate straight flow channel section 102. After the steam is completely condensed into water in the intermediate straight flow channel 102, the flow direction is turned vertically again and enters the outlet flow distribution section 103. The outlet flow distribution section 103 also adopts a secondary distribution flow channel method with a similar structure to the inlet flow distribution section 101 but in the opposite direction. All the condensate is evenly grouped and discharged from the heat exchange plate outlet.

[0049] like Figure 3 As shown, the inlet flow distribution section 101 of the hollow medium flow channel inside the heat exchange plate performs primary flow distribution by setting a flow channel partition plate 104 at the inlet, distributing the steam medium into n groups of inlet branch flow channels, each branch having a width of a1 to a2. n The flow channels have varying rectangular cross-sections. Each group of inlet branch channels turns vertically and is then divided into m straight-through channels through a two-level grouping method. Each straight-through channel inlet has an opening width d1 to d2, depending on the length and resistance of the medium flow path. m Different flow guiding structures 105 ensure that the resistance of each straight flow channel is similar, thus resulting in similar flow rates. The straight flow channels corresponding to all group inlet branches are arranged in parallel to form the intermediate straight flow channel section 102. All m straight flow channels in the intermediate straight flow channel section 102 are rectangular cross-section channels with equal width c and depth h.

[0050] like Figure 4 As shown, after the steam is completely condensed into water in the intermediate straight-through flow channel section 102, the flow direction turns vertically again and enters the outlet flow distribution section 103. The outlet flow distribution section 103 also adopts a two-stage distribution flow channel with a similar structure to the inlet flow distribution section 101 but in the opposite direction. The condensate in all the intermediate straight-through flow channels is evenly grouped and discharged from the heat exchange plate outlet. Each group outlet flow channel is a number of rectangular cross-section straight-through flow channels.

[0051] Optionally, the width of all m straight channels in the intermediate straight channel section 102 is c and the depth is h. Choosing the same size for each straight channel has the advantages of simpler processing and the same resistance in the intermediate straight channel section 102.

[0052] The working principle of the heat exchange plate is that both upper and lower surfaces of the heat exchange plate can be used for heat exchange, the steam medium enters the hollow medium flow channel in the heat exchange plate from the heat exchange plate inlet, the steam flows in the heat exchange plate and uniformly passes through the two-stage flow distribution structure of the inlet flow distribution section, and then enters the intermediate straight-through flow channel section to gradually exchange heat and condense, and after being completely condensed into water, the water flows out of the heat exchange plate from the heat exchange plate outlet. Due to the two uniform distribution processes of the steam passing through the two-stage flow distribution section, the width a1-a n and the width d1-d m of the first-stage distribution flow channel and the second-stage distribution flow channel are designed to be different sizes, the local resistance of each channel, especially the steam section with a high inlet flow rate, is controlled and adjusted, so that the overall fluid resistance of each flow channel is similar, the flow rates are basically the same, and in combination with the isothermal heat release characteristics of the steam condensation process, the wall surface temperature distribution of the heat exchange plate is evenly distributed.

[0053] In summary, the micro-channel steam condensation heat exchange plate of the application is designed for steam heat sources, the steam inlet flow channel adopts a two-stage flow distribution structure, so that the steam flow has two uniform distribution processes before entering the intermediate straight-through flow channel, through reasonable design of the key sizes of the flow channel, the fluid resistance of each intermediate straight-through flow channel is similar, the flow rates are basically the same, and in combination with the isothermal heat release characteristics of the steam condensation process, the problem of uneven wall surface temperature distribution of the same type of heat exchange plate is solved, and the overall heat exchange efficiency of the heat exchange plate is improved.

[0054] The thickness direction structure of the heat exchange plate of the application is symmetrical, the metal wall thicknesses on both sides of the flow channel are the same, and the heat exchange functions of the upper and lower surfaces of the heat exchange plate can be realized at the same time. The heat exchange plate inlet and outlet can be arranged at the diagonal positions of the heat exchange plate to form a “Z”-shaped flow channel structure, or can be arranged at the two ends of the same side of the rectangular heat exchange plate to form a “C”-shaped flow channel structure.

[0055] The heat exchange plate of the application adopts a large number of partition plates to form a compact flow distribution structure, which avoids the problem of insufficient pressure-bearing capacity caused by the use of a traditional large uniform flow space header structure in the plate.

[0056] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, any changes or replacements within the technical range disclosed in the application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the application.

Claims

1. A micro-channel steam condensing heat transfer plate, characterized in that, The application relates to a heat exchange plate, which comprises a flow channel plate (1) and a sealing plate (2) mounted on the flow channel plate (1), one side of the flow channel plate (1) is closed, and the other side is provided with a hollow medium flow channel, the hollow medium flow channel comprises an inlet flow distribution section (101), an intermediate straight-through flow channel section (102) and an outlet flow distribution section (103) connected in sequence, the inlet flow distribution section (101) and the intermediate straight-through flow channel section (102) are vertically turned, the intermediate straight-through flow channel section (102) and the outlet flow distribution section (103) are vertically turned, the inlet flow distribution section (101) is provided with a flow channel separation plate (104) for primary flow distribution, and a flow guide structure (105) is arranged at the vertical turning position between the inlet flow distribution section (101) and the intermediate straight-through flow channel section (102) for secondary flow distribution.

2. The micro-channel steam condensing heat transfer panel according to claim 1, wherein, The inlet of the inlet flow distribution section (101) and the outlet of the outlet flow distribution section (103) are arranged at diagonal positions of the rectangular heat exchange plate to form a Z-shaped flow channel structure.

3. The micro-channel steam condensing heat transfer panel according to claim 1, wherein, The inlet of the inlet flow distribution section (101) and the outlet of the outlet flow distribution section (103) are arranged at two ends of the same side of the rectangular heat exchange plate to form a C-shaped flow channel structure.

4. The micro-channel steam condensing heat transfer panel of claim 1, wherein, The intermediate straight-through flow channel section (102) has a plurality of straight-through flow channels, and the straight-through flow channels are all cross-section flow channels with equal width and depth.

5. The micro-channel steam condensing heat transfer panel of claim 4, wherein, The cross-section flow channel is a rectangular cross-section flow channel.

6. The micro-channel steam condensing heat transfer panel of claim 1, wherein, The inlet and the outlet of the straight-through flow channel are provided with the flow guide structure (105).

7. The micro-channel steam condensing heat transfer panel of claim 6, wherein, The flow guide structure (105) is provided with a circular arc surface structure to reduce local resistance, and the inlet and the outlet of the straight-through flow channel are designed to have different widths according to the length of the corresponding straight-through flow channel medium overall flow process, so that the flow resistances of all channels are similar.

8. The micro-channel steam condensing heat transfer panel of claim 1, wherein, The flow channel plate (1) and the sealing plate (2) are stacked and assembled after being processed respectively, and are formed into an integrated structure through diffusion welding.

9. The micro-channel steam condensing heat transfer panel of claim 1, wherein, The flow channel plate (1) and the sealing plate (2) are integrally manufactured.

10. The micro-channel steam condensing heat transfer panel of claim 1, wherein, The number of the sub-flow channels separated by the flow channel separation plate (104) after the inlet and the outlet of the heat exchange plate are separated is n, and the number of the intermediate straight-through flow channels of the heat exchange plate is m.

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