Plate heat exchanger core body for solid oxide fuel cell

Abstract

The utility model relates to a plate heat exchanger core body for a solid oxide fuel cell, which comprises a plurality of heat exchange plates and side sealing strips, small hemispherical bosses are arranged on the front surfaces of the heat exchange plates, large hemispherical bosses are arranged on the back surfaces of the heat exchange plates, and the small hemispherical bosses and the large hemispherical bosses are distributed in a matrix manner. The multiple side sealing strips are fixedly connected between the multiple heat exchange plates and form an inlet and an outlet, and the small hemisphere bosses and the large hemisphere bosses between the adjacent heat exchange plates in the multiple heat exchange plates are oppositely arranged and staggered. The hot side flow channels and the cold side flow channels are alternately arranged, large-area heat exchange is achieved, through the small hemispherical bosses and the large hemispherical bosses which are arranged in a protruding mode, the heat exchange area is further increased, meanwhile, complex gully flow channels are avoided, pressure drop is remarkably reduced, and efficient heat exchange is achieved. By adjusting the number and the size of the small hemispherical bosses or the large hemispherical bosses, the pressure drop of the area where the bosses are located can be adjusted, and then the heat exchange effect is adjusted.

Description

TECHNICAL FIELD

[0001] The utility model relates to solid oxide fuel cell technical field, concretely relates to a plate heat exchanger core body for solid oxide fuel cell. BACKGROUND

[0002] In the field of solid oxide fuel cell (SOFC), different manufacturers' stacks have different requirements for back pressure, and from the overall trend, the lower the back pressure, the more ideal. This is because lower pressure drop can reduce the energy consumed to overcome pressure loss, thereby effectively reducing energy consumption cost during system operation, bringing economic benefits to enterprises. At present, the size of the back pressure of the SOFC stack is closely related to multiple key components, among which the air heat exchanger, the fuel heat exchanger, the fuel preheater and the burner play a leading role. The pressure drop generated by the heat exchanger accounts for 50-60% of the entire back pressure, the pressure drop of the burner accounts for about 20-30%, and the pressure drops of the remaining components account for about 10-20% in total. Therefore, the pressure drop value of the heat exchanger directly determines the back pressure of the system to a great extent and has a crucial influence on the overall operating efficiency of the system.

[0003] The heat exchangers currently applied to SOFC systems mainly have two types: plate-fin heat exchangers and plate heat exchangers. Plate-fin heat exchangers have certain advantages, as they can relatively easily achieve a good match between heat exchange effect and pressure drop, accurately meeting the system requirements. However, their disadvantages are also quite obvious, as the large number of components and complex stacking greatly increase the difficulty of processing and manufacturing, making it difficult to mass-produce and limiting their widespread application. In contrast, although the domestic manufacturing process of plate heat exchangers has already matured and has favorable conditions for large-scale production, the flow channel structure is extremely complex, which makes it difficult to achieve perfect matching between heat exchange and pressure drop in actual application. SUMMARY

[0004] To solve the above technical problems, the utility model provides a plate heat exchanger core body for solid oxide fuel cell, which is designed to independently adjust the pressure drop on the cold and hot sides, solving the problem of matching between heat exchange and pressure drop in traditional plate heat exchangers and meeting the low pressure drop requirements of SOFC systems.

[0005] The technical scheme of the utility model is as follows: a plate heat exchanger core body for solid oxide fuel cell, comprising heat exchange plates and side seals, the front surface of the heat exchange plates is provided with small hemispherical bosses, and the back surface is provided with large hemispherical bosses, the small hemispherical bosses and the large hemispherical bosses are arranged in a matrix, there are multiple heat exchange plates, there are multiple side seals fixedly connected between the multiple heat exchange plates and forming an inlet and an outlet, and the small hemispherical bosses and the large hemispherical bosses between adjacent heat exchange plates in the multiple heat exchange plates are oppositely arranged and staggered.

[0006] Further, the side sealing strip comprises a linear side sealing strip, which is located between the heat exchange plates opposite to the small hemisphere boss.

[0007] Further, the side sealing strip comprises an L-shaped side sealing strip, which is located between the heat exchange plates opposite to the large hemisphere boss.

[0008] Further, the small hemisphere boss is provided with a small hemisphere groove at a corresponding position on the back of the heat exchange plate, and the large hemisphere boss is provided with a large hemisphere groove at a corresponding position on the front of the heat exchange plate.

[0009] Further, the plurality of heat exchange plates and the side sealing strip are fixed by welding. Compared with the prior art, the advantages of the utility model lie in that the area opposite to the small hemisphere boss is the hot side flow channel, the area opposite to the large hemisphere boss is the cold side flow channel, the hot side flow channel and the cold side flow channel are alternately arranged in the core composed of the plurality of heat exchange plates and the side sealing strip, large-area heat exchange is realized, the heat exchange area is further increased through the protruding small hemisphere boss and the large hemisphere boss, complex gully flow channels are avoided, the pressure drop is significantly reduced, high-efficiency heat exchange is realized, and the heat exchange effect can be adjusted by adjusting the number and size of the small hemisphere boss or the large hemisphere boss. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0011] Figure 1 It is a structural schematic diagram of the present application;

[0012] Figure 2 It is a structural schematic diagram of the present application; Figure 1 It is an enlarged view of A in the figure;

[0013] Figure 3 It is an exploded view of the present application;

[0014] Figure 4 It is a structural schematic diagram of the present application when the back of the heat exchange plate is upward;

[0015] Figure 5 It is a structural schematic diagram of the present application; Figure 4 It is an enlarged view of B in the figure;

[0016] Figure 6 It is a structural schematic diagram of the hot side flow channel and the cold side flow channel of the present application;

[0017] Figure 7 The working principle diagram of the hot side flow channel and the cold side flow channel.

[0018] 1, heat exchange plate; 2, linear side seal; 3, L-shaped side seal; 4, large hemisphere boss; 5, large hemisphere groove; 6, small hemisphere boss; 7, small hemisphere groove; 8, cold side flow channel; 9, hot side flow channel. DETAILED DESCRIPTION

[0019] In order to further illustrate the technical means and effects adopted by the utility model to achieve the predetermined utility model purposes, the specific embodiments, structures, features and effects according to the utility model will be described in detail as follows in combination with the drawings and preferred embodiments.

[0020] As shown in Figures 1-7 A plate heat exchanger core for solid oxide fuel cells, comprising heat exchange plates 1 and side seals, the heat exchange plates 1 are provided with small hemisphere bosses 6 on the front surface and large hemisphere bosses 4 on the back surface, the small hemisphere bosses 6 and the large hemisphere bosses 4 are distributed in a matrix shape in transverse and longitudinal linear arrays, there are multiple heat exchange plates 1, there are multiple side seals which are fixedly connected between the multiple heat exchange plates 1 and form an inlet and an outlet, the small hemisphere bosses 6 and the large hemisphere bosses 4 between adjacent heat exchange plates 1 in the multiple heat exchange plates 1 are oppositely arranged and staggered with each other; the region oppositely arranged with the small hemisphere bosses 6 is a hot side flow channel 9, the region oppositely arranged with the large hemisphere bosses 4 is a cold side flow channel 8, the hot side flow channel 9 and the cold side flow channel 8 are alternately arranged in the core composed of the multiple heat exchange plates 1 and the side seals, large-area heat exchange is realized, the heat exchange area is further increased through the protruding small hemisphere bosses 6 and the large hemisphere bosses 4, complex gully flow channels are avoided, the pressure drop is significantly reduced, high-efficiency heat exchange is realized, and the pressure drop in the region can be adjusted by adjusting the number and size of the small hemisphere bosses 6 or the large hemisphere bosses 4.

[0021] In the above embodiment, the side seal strip includes a linear side seal strip 2, which is located between the heat exchange plates opposite to the small hemispherical boss 6, that is, in the hot side flow channel 9, and the linear side seal strip 2 is symmetrically arranged left and right, and the heat exchange direction is forward and backward; the side seal strip includes an L-shaped side seal strip 3, which is located between the heat exchange plates opposite to the large hemispherical boss 4, that is, in the cold side flow channel 8, and the L-shaped side seal strip 3 is symmetrically arranged at the center, and an inlet and an outlet are left near two opposite corners of the heat exchange plate, forming a heat exchange flow direction similar to a Z-shaped; the countercurrent arrangement is adopted in the hot side flow channel 9 and the cold side flow channel 8, that is, the flow directions in the hot side flow channel 9 and the cold side flow channel 8 are opposite, and since the heat exchange plate 1 is long strip-shaped, it is divided into two short sides and two long sides, the short side is used in the hot side flow channel 9, and the long side is used in the cold side flow channel 8, further increasing the main heat exchange area. The small hemispherical boss 6 is provided with a small hemispherical groove 7 at the corresponding position on the back of the heat exchange plate 1, and the large hemispherical boss 4 is provided with a large hemispherical groove 5 at the corresponding position on the front of the heat exchange plate 1, further increasing the heat exchange area and improving the heat exchange efficiency. The plurality of heat exchange plates and the side seal strip are fixed by welding, forming a reliable and good sealing effect.

[0022] The working mode of the utility model is described as follows:

[0023] In the material preparation stage, heat-resistant stainless steel with a thickness of 0.1-1mm is selected as the raw material of the heat exchange plate 1, which can well adapt to the working environment of the fuel cell due to its high temperature resistance; the side seal strip also uses heat-resistant stainless steel to ensure good sealing and supporting performance at high temperature. In the processing and manufacturing link, since the plurality of heat exchange plates 1 are of the same model, only one set of die is needed for stamping forming, which greatly saves the die development cost, and the existing high-precision stamping equipment is used to stamp out the heat exchange plate 1 meeting the specifications with a specially customized die, and the flatness error is controlled within a very small range, ensuring the accuracy of subsequent assembly.

[0024] In the side seal processing, the side seal of the hot side flow channel 9 is made into a "I" shape, that is, a straight line type side seal 2, and the side seal of the cold side flow channel 8 is made into an "L" shape, that is, an L-shaped side seal 3; through precise cutting and polishing process, the flatness range of the upper and lower contact surfaces of the side seal with the heat exchange plate 1 is 0.01-0.05mm. In the assembly flow channel, according to the design requirements, the heat exchange plate 1, the straight line type side seal 2 and the L-shaped side seal 3 are stacked in turn; the straight line type side seal 2 is tightly attached to seal the hot side flow channel 9, effectively preventing the leakage of high-temperature fluid in the hot side flow channel 9, and at the same time providing stable support for the flow channel by virtue of its own structure; the L-shaped side seal 3 has the same effect on the cold side flow channel 8. By reasonably designing the number of flow channels, different heat exchange efficiency and pressure drop requirements can be met, such as in some application scenarios with extremely high heat exchange efficiency requirements, the number of flow channels is increased, so that the heat exchange area is greatly increased and the pressure drop is significantly reduced, realizing high-efficiency heat exchange.

[0025] For the large hemisphere boss 4 and the small hemisphere boss 6 on the heat exchange plate 1, their size accuracy is strictly controlled during the mold pressing process. The protruding surface of the large hemisphere boss 4 is located in the cold side flow channel 8, and by adjusting the size and height of the protruding surface, the pressure drop of the cold side flow channel 8 can be accurately controlled without interfering with the pressure drop of the hot side flow channel 9. For example, in a small fuel cell system adapted heat exchanger core, according to the system pressure parameters, the height of the large hemisphere boss 4 is fine-tuned to make the cold side flow channel 8 reach the ideal height, ensuring that the pressure drop is within the appropriate range under the same flow rate, while taking into account the heat exchange efficiency; the small hemisphere boss 6 independently regulates the pressure drop of the hot side flow channel 9, with the same principle.

[0026] In the sealing process, considering the high-temperature and low-pressure fluid characteristics of SOFC during operation, if the application scenario has high temperature and strict sealing durability requirements, laser welding end welding process is preferred, which uses high energy density laser beam to accurately weld the edges of multiple heat exchange plates 1 and side seals, forming a reliable seal; if cost control or relatively low working temperature is required, brazing can also be selected to achieve good sealing effect by using filler metal to melt and fill at high temperature.

[0027] Finally, by stacking multiple heat exchange plates 1 combined with side seals, a flow channel system with exquisite structure and excellent performance is formed, and a plate heat exchanger core that meets the needs of solid oxide fuel cells is made. This technology can also be expanded to make a multi-in-one heat exchanger, further improving system integration and heat exchange efficiency.

[0028] The above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A plate heat exchanger core for a solid oxide fuel cell, comprising heat exchange plates and side seals, characterized in that: The front of the heat exchange sheet is provided with small hemispherical bosses, and the back is provided with large hemispherical bosses, the small hemispherical bosses and the large hemispherical bosses are in matrix distribution, the heat exchange sheet is multiple, the side sealing strip is multiple and is fixedly connected between the multiple heat exchange sheets and forms an inlet and an outlet, and the small hemispherical bosses and the large hemispherical bosses between adjacent heat exchange sheets in the multiple heat exchange sheets are oppositely arranged and staggered.

2. The plate heat exchanger core for a solid oxide fuel cell according to claim 1, characterized in that: The side sealing strip comprises a linear side sealing strip, and the linear side sealing strip is located between the heat exchange sheets oppositely arranged with the small hemispherical bosses.

3. The plate heat exchanger core for a solid oxide fuel cell according to claim 1, characterized in that: The side sealing strip comprises an L-shaped side sealing strip, and the L-shaped side sealing strip is located between the heat exchange sheets oppositely arranged with the large hemispherical bosses.

4. The plate heat exchanger core for a solid oxide fuel cell according to claim 1, characterized in that: The small hemispherical bosses are provided with small hemispherical grooves at corresponding positions on the back of the heat exchange sheet, and the large hemispherical bosses are provided with large hemispherical grooves at corresponding positions on the front of the heat exchange sheet.

5. The plate heat exchanger core for a solid oxide fuel cell according to claim 1, characterized in that: The multiple heat exchange sheets and the side sealing strip are fixed by welding.

Images