Micro-channel heat exchanger resistant to molten salt corrosion

Abstract

The invention discloses a micro-channel heat exchanger resistant to molten salt corrosion, which comprises a plurality of micro-channel heat exchange units, and each unit comprises a plurality of micro-channel capillary tubes which are arranged in parallel and coated with first coatings at the positions except the two ends of a tube body, the upper partition plate and the lower partition plate can cover all the micro-channel capillary tubes, the positions, corresponding to the first coatings, of the partition plates are coated with second coatings, the two filling assemblies are located at the front ends and the rear ends of the micro-channel capillary tubes and used for gap filling, and the two side plates are located on the left sides and the right sides of the micro-channel capillary tubes and used for gap insertion. According to the heat exchanger, on the premise that the size and the manufacturing cost of the heat exchanger are not remarkably increased, remarkable fused salt corrosion resistance and oxidation resistance functions are achieved, and the service life of the heat exchanger in a fused salt medium is effectively prolonged.

Description

Technical Field

[0001] The 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 is a heat exchanger with a channel equivalent diameter of 10-1000μm. It includes a flat tube with dozens of fine flow channels inside and a liquid collecting tube connected to the flat tube. The collecting tube is provided with a partition that divides the heat exchanger flow channel into multiple processes. The microchannel heat exchanger is small in size, light in weight, has outstanding heat exchange performance, and is highly efficient and energy-saving. It is widely used in many fields such as automobiles, home appliances, new energy, and microelectronics. Among them, in some fields, such as solar power generation, microchannel heat exchangers will work in molten salt media for a long time, and there is a problem of short service life due to long-term erosion by molten salt.

[0003] To solve the problem of molten salt corrosion of 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, but 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 solution of the present invention is 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 and arranged in parallel and reach the size of a capillary, 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 covering all the microchannel capillaries, two groups 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 the right side 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 thereon, the second coating is in contact with the first coating, the length of the front edge or the rear edge is equal to the length of the front end or the rear end not coated with the first coating; any of the filling components comprises two filling plates of the same structure, the two filling plates can be filled into the upper and lower gaps between the front edge or the rear edge and the front end or the rear end, the thickness of the filling plates is the sum of the thickness of the first coating and the thickness of the second coating; any of the side plates can be inserted into the left and right gaps between the left edge or the right edge and both sides of all the microchannel capillaries, 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 capillaries; the first coating and the second coating use corrosion-resistant and oxidation-resistant coating materials.

[0007] In the above technical scheme 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 oxidation resistance. 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, and improving the welding strength, thereby 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 oxidation-resistant 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 a 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 rear 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 partition panels 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 plate is a 4K and / or 8K mirror plate.

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

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

[0013] According to some preferred embodiments of the present invention, the coating material is selected from one or more of nano-ceramics, aluminum oxide, and magnesium oxide.

[0014] According to some preferred embodiments of the present invention, the microchannel heat exchanger is obtained by stacking a plurality of microchannel heat exchange units and then performing vacuum diffusion welding.

[0015] The present invention has the following beneficial effects:

[0016] The present invention can significantly improve the anti-corrosion and anti-oxidation capabilities of microchannel heat exchange by adding a small amount of coating at a specific position.

[0017] The present invention can utilize vacuum diffusion welding technology to combine different heat exchange units into an integrally formed heat exchanger, thereby ensuring that the heat exchanger is corrosion-resistant and oxidation-resistant and further increasing its overall strength.

[0018] When the present invention is used in a molten salt corrosion environment, there is no need to increase the thickness of the middle partition. The side of the heat exchanger in contact with the molten salt contains an anti-corrosion and anti-oxidation coating, while the other side can also use general materials, which significantly reduces the overall volume of the corrosion-resistant heat exchanger.

[0019] When the present invention is applied under extreme working conditions, even if the flow channel on the molten salt side of the heat exchanger is completely corroded, that is, the metal part of the capillary is corroded, the flow structure of the combined welded coating can still be ensured to remain unchanged, thereby maintaining the normal working capacity of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural exploded view of the molten salt corrosion-resistant microchannel heat exchange unit of the present invention.

[0021] Figure 2 It is a front cross-sectional view of the microchannel heat exchange unit resistant to molten salt corrosion of the present invention.

[0022] Figure 3 It is a schematic top view of a partition in the molten salt corrosion resistant microchannel heat exchange unit of the present invention.

[0023] Figure 4 The figure is a schematic diagram of the installation of the filling plate in the molten salt corrosion resistant microchannel heat exchange unit of the present invention. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0025] According to the technical solution of the present invention, in some specific embodiments, the molten salt corrosion-resistant microchannel heat exchanger includes a plurality of microchannel heat exchange units, which can be obtained by combining and stacking the microchannel heat exchange units in different forms and performing vacuum diffusion welding according to application needs such as countercurrent or cross flow.

[0026] For further information, see Attachment Figure 1-4 The microchannel heat exchange unit comprises: a plurality of micro-pipes, namely, microchannel capillaries 3, which are open at both ends and arranged in parallel and reach the size of a capillary tube. Each microchannel capillary 3 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 2 located above and below the microchannel capillary 3 and completely covering the microchannel capillary 3, two groups of filling components located at the front end and the rear end of the microchannel capillary 3, and two side plates 1 located on the left and right sides of the microchannel capillary 3, wherein any baffle 2 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 with the microchannel capillary 3. The first coatings of the microchannel capillary 3 are in contact with each other, and 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 microchannel capillary 3 not coated with the first coating; any filling assembly includes two filling plates 4 with the same structure, and the two filling plates 4 can be filled into the upper and lower gaps between the front edge or the rear edge of the plate body of the partition 2 and the front end or the rear end of the microchannel capillary 3, that is, the thickness of the filling plates 4 is the sum of the thickness of the first coating and the second coating; any side plate 1 can be inserted into the left edge or the right edge of the plate body of the partition 2 and the left and right gaps on both sides of the microchannel capillary 3, that is, 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, and its width can be set according to the working conditions.

[0027] In some specific embodiments, the number of microchannel capillaries 3 can be determined according to actual use conditions.

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

[0029] In some preferred embodiments, the side panels 1 , the partition panels 2 and the filling panels 4 are made of stainless steel mirror panels, preferably 4K and / or 8K mirror panels.

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

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

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

[0033] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

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 microchannels, i.e., microchannel capillaries, which are open at both ends and arranged in parallel and reach the size of a capillary, wherein each of the microchannel capillaries is uniformly coated with a first coating on its tube body except for the two ends, i.e., the front end and the rear end; the microchannel heat exchange unit also comprises two baffles located above and below the microchannel capillaries and covering all the microchannel capillaries, two groups 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 the right side of all the microchannel capillaries; wherein any of the baffles comprises a plate body and a second coating uniformly coated on the plate body except for the four edges, i.e., the front edge, the rear edge, the left edge and the right edge thereof, and the second coating is uniformly coated with the first coating. The first coatings are in contact with each other, and the length of the front edge or the rear edge is equal to the length of the front end or the 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 the rear edge and the front end or the rear end, and the thickness of the filling plate 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 the right edge and both sides of 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 plates, the partition plates and the filling plates are all made of stainless steel mirror plates.

4. The microchannel heat exchanger according to claim 1, characterized in that: The stainless steel mirror plate is a 4K and / or 8K mirror plate.

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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