Fused salt corrosion resistant microchannel heat exchanger

Abstract

The application discloses a micro-channel heat exchanger resistant to molten salt corrosion, which comprises a plurality of micro-channel heat exchange units, each of which comprises: a plurality of micro-channel capillary tubes which are arranged in parallel and coated with a first coating layer at positions outside both ends of a pipe body, upper and lower two partition plates which can cover all the micro-channel capillary tubes and are coated with a second coating layer at positions corresponding to the first coating layer, and two groups of gap filling components located at the front and back ends of the micro-channel capillary tubes and two side plates located at the left and right sides of the micro-channel capillary tubes. The heat exchanger of the application can obtain significant molten salt corrosion resistance and oxidation resistance without significantly increasing the volume and manufacturing cost of the heat exchanger, and effectively prolongs the service life of the heat exchanger in a molten salt medium.

Description

Technical Field

[0001] The present invention relates to the technical field of microchannel heat exchangers, in particular to a microchannel heat exchanger resistant to molten salt corrosion. Background Art

[0002] A microchannel heat exchanger (MCHE) has a channel equivalent diameter of 10-1000μm. It consists of flat tubes with dozens of microscopic channels and a manifold connected to the tubes. The manifold is equipped with partitions that divide the heat exchanger's flow channels into multiple flow paths. Microchannel heat exchangers are compact, lightweight, offer outstanding heat transfer performance, and are highly efficient and energy-efficient. They are widely used in a variety of fields, including automotive, home appliances, new energy, and microelectronics. However, in some areas, such as solar power generation, MCHs operate in molten salt media for extended periods, resulting in a short service life due to long-term corrosion from the molten salt.

[0003] To solve the problem of molten salt corrosion in microchannel heat exchangers, commonly used methods in the prior art mainly include increasing the thickness of the heat exchanger partition layer and using more corrosion-resistant materials. However, these two methods will bring new problems of excessively large heat exchanger volume and high cost. Summary of the Invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide a new type of microchannel heat exchanger resistant to molten salt corrosion, which can obtain significant molten salt corrosion resistance and oxidation resistance without significantly increasing the volume and manufacturing cost of the heat exchanger, thereby effectively extending its service life in the molten salt medium.

[0005] The technical solutions of the present invention are as follows:

[0006] A microchannel heat exchanger resistant to molten salt corrosion, comprising: a plurality of microchannel heat exchange units; the microchannel heat exchange units comprise: a plurality of micro-pipes, namely, microchannel capillaries, which are open at both ends, arranged in parallel, and reach the size of capillaries, wherein each of the microchannel capillaries is uniformly coated with a first coating on its tube body except for the two ends, namely, the front end and the rear end; the microchannel heat exchange unit also comprises two baffles located above and below the microchannel capillaries and capable of covering all the microchannel capillaries, two sets of filling components located at the front end and the rear end of all the microchannel capillaries, and two side plates located on the left and right sides of all the microchannel capillaries; wherein any of the baffles comprises a plate body and a plate body uniformly coated with a first coating on the plate body except for the four edges, namely, the front edge, the rear edge, the left edge and the right edge thereof A second coating is applied to the microchannel capillary tube, the second coating is in contact with the first coating, and the length of the front edge or rear edge is equal to the length of the front end or rear end not coated with the first coating; any of the filling components includes two filling plates with the same structure, and the two filling plates can be filled into the upper and lower gaps between the front edge or rear edge and the front end or rear end, and the thickness of the filling plates is the sum of the thickness of the first coating and the second coating; any of the side plates can be inserted into the left and right gaps between the left edge or right edge and all the microchannel capillaries, and the thickness of the side plates is the sum of the thickness of the first coating, the thickness of the second coating and the diameter of the microchannel capillary tube; the first coating and the second coating use corrosion-resistant and oxidation-resistant coating materials.

[0007] In the above technical solution of the present invention, the surface within the flow medium range of the upper and lower partitions contains a second coating, which can effectively enhance its corrosion resistance and antioxidant ability. The edges around them are not sprayed with coating, which can be used as reserved space when the heat exchange unit is assembled, ensuring the material consistency during vacuum diffusion welding, improving the welding strength, and further improving the overall pressure-bearing capacity of the heat exchanger; the outer ring of the microchannel capillary is also evenly sprayed with a corrosion-resistant and antioxidant coating, namely the first coating, and its two ends are not sprayed, which can not only ensure the matching and combination stability between the components in the unit, but also serve as reserved space when the heat exchange unit is assembled, ensuring the material consistency during vacuum diffusion welding, improving the welding strength, and improving the pressure-bearing capacity of the heat exchanger; further, in order to enhance the combination stability and tightness between the components in the unit, the microchannel heat exchange unit is provided with side panels and filling panels for filling the front and back and left and right gaps.

[0008] According to some preferred embodiments of the present invention, the diameter of the microchannel capillary is 0.9-2.5 mm.

[0009] According to some preferred embodiments of the present invention, the side panels, the partitions, and the filling panels are all made of stainless steel mirror panels.

[0010] According to some preferred embodiments of the present invention, the stainless steel mirror panel is a 4K and / or 8K mirror panel.

[0011] According to some preferred embodiments of the present application, the first coating thickness is equal to the second coating thickness.

[0012] According to some preferred embodiments of the present application, the thickness of the first coating or the second coating is 0.1-2mm.

[0013] According to some preferred embodiments of the present application, the coating material is selected from one or more of nanoceramics, alumina, magnesium oxide.

[0014] According to some preferred embodiments of the present application, the micro-channel heat exchanger is obtained by vacuum diffusion welding after stacking several micro-channel heat exchange units.

[0015] The present application has the following advantages:

[0016] The present application can significantly improve the corrosion resistance and oxidation resistance of micro-channel heat exchange by adding a small amount of coating at a specific location.

[0017] The present application can use vacuum diffusion welding technology to combine different heat exchange units into a heat exchanger, which can ensure the corrosion resistance and oxidation resistance of the heat exchanger while further increasing its overall strength.

[0018] The present application does not need to increase the thickness of the intermediate partition plate when applied in a molten salt corrosion environment. The side of the heat exchanger in contact with the molten salt contains a corrosion-resistant and oxidation-resistant coating, while the other side can use general materials, significantly reducing the overall volume of the corrosion-resistant heat exchanger.

[0019] The present application can ensure the flow structure of the coating after combined welding unchanged and maintain the normal working capacity of the heat exchanger even if the flow channel of the heat exchanger on the molten salt side is completely corroded and the metal part of the capillary tube is corroded when applied in extreme conditions. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural exploded view of the molten salt corrosion-resistant micro-channel heat exchange unit of the present application.

[0021] Figure 2 is a sectional front view of the molten salt corrosion-resistant micro-channel heat exchange unit of the present application.

[0022] Figure 3 is a top view of the partition plate in the molten salt corrosion-resistant micro-channel heat exchange unit of the present application.

[0023] Figure 4 is an installation schematic of the filler plate in the molten salt corrosion-resistant micro-channel heat exchange unit of the present application. DETAILED DESCRIPTION

[0024] The application will be described in detail below with reference to the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplarily describe the application and cannot constitute any limitation to the protection scope of the application. All reasonable variations and combinations within the inventive concept of the application fall within the protection scope of the application.

[0025] According to the technical solution of the application, in some specific embodiments, the molten salt corrosion resistant micro-channel heat exchanger comprises a plurality of micro-channel heat exchange units, which can be combined in different forms according to the needs of the application, such as the needs of counterflow or crossflow, and then vacuum diffusion welding is performed to obtain the micro-channel heat exchanger.

[0026] Further, with reference to the accompanying drawings Figures 1-4 The micro-channel heat exchange unit comprises a plurality of open-ended, parallel arranged, capillary-sized micro-pipes, i.e. micro-channel capillary tubes 3, each of which is uniformly coated with a first coating layer on the pipe body except for the two ends, i.e. the front end and the rear end. The micro-channel heat exchange unit further comprises two baffles 2 located above and below the micro-channel capillary tubes 3, which can completely cover the micro-channel capillary tubes 3, two groups of filling components located at the front end and the rear end of the micro-channel capillary tubes 3, and two side plates 1 located at the left side and the right side of the micro-channel capillary tubes 3. Any baffle 2 comprises a plate body and a second coating layer uniformly coated on the plate body except for the four peripheral edges, i.e. the front edge, the rear edge, the left edge and the right edge. The second coating layer is in contact with the first coating layer of the micro-channel capillary tube 3. The length of the front edge or the rear edge is equal to the length of the front end or the rear end of the micro-channel capillary tube 3 which is not coated with the first coating layer. Any filling component comprises two filling plates 4 with the same structure, which can be filled into the upper and lower gaps between the front edge or the rear edge of the plate body of the baffle 2 and the front end or the rear end of the micro-channel capillary tube 3, i.e. the thickness of the filling plate 4 is the sum of the thicknesses of the first coating layer and the second coating layer. Any side plate 1 can be inserted into the left edge or the right edge of the plate body of the baffle 2 and the left and right gaps on both sides of the micro-channel capillary tube 3, i.e. the thickness of the side plate is the sum of the thicknesses of the first coating layer, the second coating layer and the diameter of the micro-channel capillary tube, and its width can be set according to the working condition.

[0027] In some specific embodiments, the number of micro-channel capillary tubes 3 can be determined according to the actual use condition.

[0028] In some preferred embodiments, the diameter of the micro-channel capillary tube 3 is 0.9-2.5mm.

[0029] In some preferred embodiments, the materials of the side plate 1, the baffle 2 and the filling plate 4 are stainless steel mirror plates, preferably 4K and / or 8K mirror plates.

[0030] In some preferred embodiments, the thickness of the first coating layer is equal to the thickness of the second coating layer.

[0031] More preferably, the first coating thickness or the second coating thickness is 0.1-2mm.

[0032] In some embodiments, the first coating and the second coating are corrosion resistant and oxidation resistant coatings, and the coating material can be selected from one or more of nano-ceramics, alumina, magnesium oxide.

[0033] The above embodiments are only preferred embodiments of the present application, and the protection scope of the present application is not limited to the above embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, improvements and refinements without departing from the principles of the present application shall also be considered as falling within the protection scope of the present application.

Claims

1. A microchannel heat exchanger resistant to molten salt corrosion, characterized in that: It includes: Several microchannel heat exchange units; The microchannel heat exchange unit comprises: a plurality of micro-pipes, namely microchannel capillaries, which are open at both ends, arranged in parallel, and reach the size of a capillary tube, wherein each of the microchannel capillaries is uniformly coated with a first coating on its tube body except for the two ends, namely the front end and the rear end; the microchannel heat exchange unit also comprises two partitions located above and below the microchannel capillaries and capable of covering all the microchannel capillaries, two sets of filling components located at the front end and the rear end of all the microchannel capillaries, and two side plates located on the left and right sides of all the microchannel capillaries; wherein any of the partitions comprises a plate body and a second coating uniformly coated on the plate body except for the four edges, namely the front edge, the rear edge, the left edge and the right edge thereof, and the second coating is uniformly coated on the plate body except for the four edges, namely the front edge, the rear edge, the left edge and the right edge thereof, and the second coating is uniformly coated on the plate body except for the four edges, namely the front edge, the rear edge, the left edge and the right edge thereof. The first coatings are in contact with each other, and the length of the front edge or rear edge is equal to the length of the front end or rear end not coated with the first coating; any of the filling components includes two filling plates with the same structure, and the two filling plates are filled in the upper and lower gaps between the front edge or rear edge and the front end or rear end, and the thickness of the filling plates is the sum of the thicknesses of the first coating and the second coating; any of the side plates can be inserted into the left and right gaps between the left edge or right edge and all the microchannel capillaries, and the thickness of the side plate is the sum of the thickness of the first coating, the thickness of the second coating and the diameter of the microchannel capillary; the first coating and the second coating use corrosion-resistant and oxidation-resistant coating materials.

2. The microchannel heat exchanger according to claim 1, characterized in that: The diameter of the microchannel capillary is 0.9-2.5 mm.

3. The microchannel heat exchanger according to claim 1, characterized in that: The side panels, the partitions and the filling panels are all made of stainless steel mirror panels.

4. The microchannel heat exchanger according to claim 3, characterized in that: The stainless steel mirror panel is a 4K and / or 8K mirror panel.

5. The microchannel heat exchanger according to claim 1, characterized in that: The first coating thickness is equal to the second coating thickness.

6. The microchannel heat exchanger according to claim 5, characterized in that: The thickness of the first coating layer or the second coating layer is 0.1-2 mm.

7. The microchannel heat exchanger according to claim 1, characterized in that: The coating material is selected from one or more of nano-ceramics, aluminum oxide, and magnesium oxide.

8. The microchannel heat exchanger according to any one of claims 1 to 7, characterized in that: The microchannel heat exchanger is obtained by stacking a plurality of microchannel heat exchange units and then performing vacuum diffusion welding.

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