Printed circuit board heat exchanger

Abstract

The application provides a printed circuit board type heat exchanger, and belongs to the technical field of heat exchangers, and specifically comprises a heat exchange plate, a cold fluid channel, a hot fluid channel and a heating assembly, wherein the heating assembly is used for directly or indirectly heating the hot fluid medium of the fluid channel when the temperature of the hot fluid medium in the hot fluid channel is lower than a preset temperature. Through the processing scheme, when the temperature of the heat exchanger plate approaches the freezing point temperature of molten salt or liquid metal and its alloy, the heating mode is quickly started, the temperature of the heat exchange plate is raised, and the heat exchange channel is prevented from being blocked.

Description

Technical Field

[0001] The present application relates to the field of heat exchangers, and in particular to a printed circuit board type heat exchanger. Background Art

[0002] Printed circuit board heat exchangers feature a compact structure, high heat transfer efficiency, and the ability to withstand high temperatures and high pressures. A common manufacturing method for printed circuit board heat exchangers involves machining tiny heat transfer channels into the heat transfer plates. The plates are then stacked and solid cover plates are added to the top and bottom. Vacuum diffusion welding is then used to form the heat transfer core. Finally, headers are welded to the core ends to complete the heat exchanger.

[0003] Currently, printed circuit board heat exchangers are widely used in the solar and nuclear energy sectors. In these fields, media such as molten salts, liquid metals, and their alloys are highly suitable as heat transfer media due to their excellent heat transfer capabilities at normal pressure and their high boiling points. However, the freezing point of molten salts, liquid metals, and their alloys is typically between 120°C and 200°C, far higher than the ambient temperature. In nuclear or solar energy systems, the media used for heat exchange with molten salts, liquid metals, and their alloys are typically water, air, thermal oil, and the like. While these media can still flow and exchange heat at room temperature, they can easily cause the temperature of the heat exchange plates on the molten salt or liquid metal side to fall below the freezing point of the fluid, causing the molten salt or liquid metal to solidify and block the heat exchange channels. Summary of the Invention

[0004] In view of this, the present application provides a printed circuit board type heat exchanger, which solves the problems in the prior art. When the temperature of the heat exchanger plate approaches the solidification point temperature of molten salt or liquid metal and its alloys, the heating mode is quickly turned on to increase the temperature of the heat exchange plate and prevent the heat exchange channel from being blocked.

[0005] The printed circuit board heat exchanger provided in this application adopts the following technical solution:

[0006] A printed circuit board type heat exchanger includes heat exchange plates, cold fluid channels, hot fluid channels and a heating assembly. The heating assembly is used to directly or indirectly heat the hot fluid medium in the hot fluid channel when the wall temperature of the hot fluid channel or the temperature of the hot fluid medium in the hot fluid channel is lower than a preset temperature.

[0007] Optionally, the heating component is an electric heating wire, and the electric heating wire is located in the cold fluid channel, the hot fluid channel, or the wall structure of the fluid channel.

[0008] Optionally, the electric heating wire is located in the cold fluid channel, and the electric heating wire is spiral-shaped.

[0009] Optionally, the printed circuit board heat exchanger includes a plurality of cold fluid channels, each of the cold fluid channels is provided with the electric heating wire, and the electric heating wire in the cold fluid channel runs through the entire cold fluid channel.

[0010] Optionally, the printed circuit board type heat exchanger includes a plurality of stacked heat exchange plates, each of which includes a metal plate, a plurality of fluid grooves being provided on one side of the metal plate, the other side of the metal plate being a plane, the inner wall profile of the fluid groove being an arc or a rectangle, the solid part between adjacent fluid grooves serving as ribs, and two adjacent heat exchange plates. The metal plate plane of one heat exchange plate is connected to the ribs on the other heat exchange plate, the fluid grooves on one metal plate and the plane of the other metal plate form a fluid channel, the electric heating wire is located on the ribs or the metal plate, and the heat exchange plates are divided into cold side heat exchange plates and hot side heat exchange plates, the fluid grooves on the metal plate of the cold side heat exchange plate contain a cold fluid medium, and the fluid grooves on the metal plate of the hot side heat exchange plate contain a hot fluid medium.

[0011] Optionally, the electric heating wire is located in the fins of the cold-side heat exchange plate or on the solid wall surface of the fluid channel on the cold-side heat exchange plate.

[0012] Optionally, a placement groove for accommodating an electric heating wire is provided on the side of the rib facing away from the bottom of the fluid groove; and a placement groove for accommodating an electric heating wire is provided on the side of the solid frame of the metal sheet facing the other heat exchange plate.

[0013] Optionally, the hot fluid medium in the hot fluid channel is molten salt or liquid metal and its alloys, and the preset temperature is greater than or equal to the solidification temperature of the molten salt or liquid metal and its alloys.

[0014] In summary, this application has the following beneficial technical effects:

[0015] The present application designs a heating component in the heat exchanger. When the temperature in the hot fluid channel drops and the hot fluid medium solidifies, the heating component is started to heat the heat exchange plate, thereby increasing the temperature of the hot fluid medium and keeping the hot fluid in a liquid state, so that the hot fluid maintains good fluidity. At the same time, the heating component has limited heating of the hot fluid, ensuring that the hot fluid temperature of the heat exchanger is lower than the temperature before the hot fluid enters the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 This is a schematic diagram of the distribution structure of the cold fluid channel and the electric heating wire in the embodiment of the present application;

[0018] Figure 2 This is a schematic diagram of the structure of the cold side heat exchange plate and the hot side heat exchange plate in this application.

[0019] Explanation of the accompanying drawings: 1. heat exchange plate; 101. cold side heat exchange plate; 102. hot side heat exchange plate; 11. metal sheet; 12. rib; 13. solid frame; 14. fluid groove; 2. placement groove; 3. cold fluid channel; 4. electric heating wire; 5. hot fluid channel. DETAILED DESCRIPTION

[0020] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0021] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0022] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0023] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0024] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples. However, one skilled in the art will appreciate that the aspects described can be practiced without these specific details.

[0025] An embodiment of the present application provides a printed circuit board type heat exchanger.

[0026] like Figure 1 and Figure 2 As shown, a printed circuit board type heat exchanger includes a heat exchange plate 1, a cold fluid channel 3, a hot fluid channel 5 and a heating component. The heating component is used to directly or indirectly heat the hot fluid medium in the fluid channel 5 when the wall temperature of the hot fluid channel 5 or the temperature of the hot fluid medium in the hot fluid channel 5 is lower than a preset temperature.

[0027] Generally, when designing a heat exchanger, parameters such as the flow rate of the cold fluid are determined based on the operating conditions and the flow rate of the hot fluid, so as to keep the temperature of the hot fluid within a reasonable range as much as possible. However, in actual use, it cannot be guaranteed that the temperature of the hot fluid is always within the design range. When the hot fluid uses a medium material that is easy to solidify at room temperature or higher, if the wall temperature of the hot fluid channel 5 or the temperature of the hot fluid medium drops to its freezing point or below, the hot fluid channel 5 will be blocked. Therefore, the present application designs a heating component in the heat exchanger. When the wall temperature of the hot fluid channel 5 or the temperature in the hot fluid channel 5 drops and the hot fluid medium solidifies, the heating component is started to heat the heat exchange plate 1, thereby increasing the wall temperature of the hot fluid channel 5 and the temperature of the hot fluid medium, so that the hot fluid remains in a liquid state and maintains good fluidity. At the same time, the heating component has limited heating of the hot fluid, ensuring that the hot fluid temperature of the heat exchanger is lower than the temperature before the hot fluid enters the heat exchanger.

[0028] In the embodiment of the present application, the hot fluid medium in the hot fluid channel 5 is a molten salt or liquid metal or its alloys. The preset temperature is greater than or equal to the solidification temperature of the molten salt or liquid metal or its alloys. The specific preset temperature can be set according to actual conditions. To monitor the temperature of the hot fluid medium, a temperature sensor probe can be installed in the wall of the hot fluid channel 5, or the temperature sensor probe can be designed at the outlet of each hot fluid channel 5 on the heat exchanger.

[0029] The printed circuit board type heat exchanger includes a plurality of heat exchange plates 1, and a plurality of heat exchange plates 1 are stacked to form the printed circuit board type heat exchanger. The heat exchange plate 1 includes a metal plate 11. The heat exchange plate 1 includes a metal plate 11. A plurality of fluid grooves 14 are provided on one side of the metal plate 11. The other side of the metal plate 11 is a plane. The inner wall profile of the fluid groove 14 is an arc or a rectangle. The solid part between adjacent fluid grooves 14 serves as a fin 12. Among two adjacent heat exchange plates 1, the fin of one heat exchange plate 1 The plane of the metal sheet 11 is connected to the fins 12 on the other heat exchange plate 1. The fluid groove 14 on one metal sheet 11 and the plane of the other metal sheet 11 form a fluid channel. The electric heating wire 4 is located on the fins 12 or the metal sheet 11. The heat exchange plate 1 is divided into a cold side heat exchange plate 101 and a hot side heat exchange plate 102. The fluid groove 14 on the metal sheet 11 of the cold side heat exchange plate 101 contains a cold fluid medium, and the fluid groove 14 on the metal sheet 11 of the hot side heat exchange plate 102 contains a hot fluid medium. The fluid channel of the cold side heat exchange plate 101 is the cold fluid channel 3, and the fluid channel of the hot side heat exchange plate 102 is the hot fluid channel 5.

[0030] The fluid channel structure is formed by etching or mechanically processing the metal sheet 11 to form fluid grooves 14, and finally forming the heat exchange plate 1; the contact areas of adjacent heat exchange plates 1 are welded into a core by vacuum diffusion welding, and then the heads and inlet and outlet pipes are processed by argon arc welding at the inlet and outlet of the core, and the heat exchanger is insulated to complete the processing of the heat exchanger.

[0031] The heating component is an electric heating wire 4, which is located in the cold fluid channel 3, the hot fluid channel 5 or the wall structure of the fluid channel. The two ends of the electric heating wire 4 are connected to the circuit and energized to heat the heat exchanger.

[0032] In the embodiment of the present application, since the operating pressure of the molten salt or liquid metal and its alloy is slightly higher than atmospheric pressure, in order to prevent the heating resistance wire from increasing the flow resistance of the hot side channel, the electric heating wire is not placed in the hot fluid channel 5, and the electric heating wire 4 is placed on the solid wall surface of the cold fluid channel 3. For example, the electric heating wire 4 can be designed to be on the fin 12 or the metal sheet 11.

[0033] More specifically, the side of the rib 12 facing away from the bottom of the fluid groove 14 is provided with a placement groove 2 for accommodating the electric heating wire 4, and the side of the solid frame 13 at the edge of the metal sheet 11 facing the other heat exchange plate 1 is provided with a placement groove 2 for accommodating the electric heating wire 4, that is, the electric heating wire 4 is distributed on the side of the metal solid area on both sides of the fluid channel facing the other heat exchange plate 1, and the electric heating wire 4 directly passes through the internal space of the fluid channel between the ends of the two solid areas, so that there is only one continuous electric heating wire 4 in one heat exchange plate 1. The ribs 12 of the cold side heat exchange plate 101 and the electric heating wire 4 on the solid frame can directly contact the hot side heat exchange plate 102, thereby quickly heating the hot side heat exchange plate 102 to quickly heat the hot fluid medium.

[0034] The cold fluid medium flowing in the cold fluid channel 3 is typically water, steam, air, thermal oil, etc., and the flow driving pressure is relatively high. The presence of the electric heating wire 4 has little effect on the pressure drop. Alternatively, the electric heating wire 4 can be processed into a spiral shape and placed in the cold fluid channel 3. Because the cold fluid has a high thermal resistance, placing the electric heating wire 4 in the cold fluid channel 3 increases fluid turbulence, enhances heat exchange, and thus reduces thermal resistance. Furthermore, the thinness of the electric heating wire 4 increases the pressure drop, but this is acceptable compared to the benefits.

[0035] The fluid channels can be straight or zigzag. The hydraulic diameter of straight or zigzag channels ranges from 0.5 to 50 mm, the fin thickness ranges from 5 to 10 mm, and the heat exchange plate 1 thickness ranges from 1 to 5 mm. The metal sheet 11 is made of 1 to 10 mm thick metal sheet and can be made of 316 stainless steel, 304 stainless steel, 316L stainless steel, TA1 titanium alloy, TC4 titanium alloy, high-temperature alloy, aluminum, or other materials.

[0036] The electric heating wire 4 is made of nickel-chromium alloy, tungsten, platinum-rhodium alloy, etc.

[0037] In one embodiment, the electric heating wire 4 is located in the cold fluid channel 3 and is spiral-shaped.

[0038] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A printed circuit board type heat exchanger, characterized in that: The invention comprises a heat exchange plate (1), a cold fluid channel (3), a hot fluid channel (5) and a heating component, wherein the heating component is used to directly or indirectly heat the hot fluid medium in the hot fluid channel (5) when the wall temperature of the hot fluid channel (5) or the temperature of the hot fluid medium in the hot fluid channel (5) is lower than a preset temperature; The heating component is an electric heating wire (4); The electric heating wire (4) is located in the cold fluid channel (3), and the electric heating wire (4) is spiral-shaped.

2. The printed circuit board type heat exchanger according to claim 1, characterized in that: The printed circuit board type heat exchanger comprises a plurality of cold fluid channels (3), each of the cold fluid channels (3) is provided with the electric heating wire (4), and the electric heating wire (4) in the cold fluid channel (3) runs through the entire cold fluid channel (3).

3. The printed circuit board type heat exchanger according to claim 1, characterized in that: The printed circuit board type heat exchanger comprises a plurality of stacked heat exchange plates (1), wherein the heat exchange plates (1) comprise a metal sheet (11), a plurality of fluid grooves (14) are provided on one side of the metal sheet (11), the other side of the metal sheet (11) is a plane, the inner wall profile of the fluid groove (14) is an arc or a rectangle, the solid portion between adjacent fluid grooves (14) serves as a fin (12), and in two adjacent heat exchange plates (1), the plane of the metal sheet (11) of one heat exchange plate (1) and the fins on the other heat exchange plate (1) are (12) is connected, the fluid groove (14) on one metal sheet (11) and the plane of the other metal sheet (11) form a fluid channel, the electric heating wire (4) is located on the rib (12) or the metal sheet (11), the heat exchange plate (1) is divided into a cold side heat exchange plate (101) and a hot side heat exchange plate (102), the fluid groove (14) on the metal sheet (11) of the cold side heat exchange plate (101) contains a cold fluid medium, and the fluid groove (14) on the metal sheet (11) of the hot side heat exchange plate (102) contains a hot fluid medium.

4. The printed circuit board type heat exchanger according to claim 3, characterized in that: The electric heating wire (4) is located in the fins (12) of the cold side heat exchange plate (101) or on the solid wall surface of the fluid channel on the cold side heat exchange plate (101).

5. The printed circuit board type heat exchanger according to claim 1, characterized in that: The hot fluid medium in the hot fluid channel (5) is molten salt or liquid metal and its alloy, and the preset temperature is greater than or equal to the solidification temperature of the molten salt or liquid metal and its alloy.

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