KR-102964592-B1 - Manufacturing Method of Layered Heat Exchanger for Fuel Cell and Layered Heat Exchanger for Fuel Cell Manufactured by The Same

Abstract

A method for manufacturing a stacked heat exchanger for a fuel cell comprises: heat transfer plates arranged in a multi-stage overlapping configuration at regular intervals; frames installed to maintain the spacing between the heat transfer plates and allow fluid to be transferred between the heat transfer plates; and heat transfer fins installed to increase the heat transfer surface area while in contact with the fluid transferred between the heat transfer plates. The method comprises: a first step of sequentially aligning the frames, heat transfer plates, and heat transfer fins with a pre-assembly jig; a second step of setting a guide jig for guiding the spot welding location on the heat transfer plates and spot welding the guided location to temporarily fix the frames and heat transfer fins to the heat transfer plates; and a third step of stacking the pre-assembly unit stacks in which the heat transfer plates, frames, and heat transfer fins are temporarily fixed in a multi-stage configuration and brazing welding while being pressurized and supported by a brazing jig.

Inventors

• 김동진
• 유제두
• 류보현

Assignees

• (주)에프씨아이

Dates

Publication Date

20260513

Application Date

20230927

Claims (7)

1. A method for manufacturing a stacked heat exchanger for a fuel cell comprising: heat transfer plates arranged in a multi-stage overlapping configuration at regular intervals; frames installed to maintain the spacing between the heat transfer plates and to allow fluid to be transferred between the heat transfer plates; and heat transfer fins installed to increase the heat transfer surface area while in contact with the fluid transferred between the heat transfer plates. A first step of sequentially aligning the frame, the heat transfer plate, and the heat transfer fins to a pre-assembly jig, and A second step of setting a guide jig for guiding the spot welding execution location on the above-mentioned heat transfer plate and spot welding the guided location to temporarily fix the above-mentioned frame and heat transfer fin to the above-mentioned heat transfer plate, and The method includes a third step of stacking pre-assembled unit stacks in which the above-mentioned heat transfer plates, frames, and heat transfer fins are temporarily fixed in multiple layers and brazing welding while being supported by pressure with a brazing jig. The above pre-assembly jig is, A body forming the exterior, and A first groove formed on the upper side of the body corresponding to the shape of the heat transfer plate so that the heat transfer plate can be aligned with the upper side of the body, and It includes a second groove formed so that the frame is fixed to the bottom surface of the first groove, and A method for manufacturing a stacked heat exchanger for a fuel cell, characterized in that one or more push holes are formed through the lower side of the body to push the pre-assembled unit stack with a pusher and discharge it from the first groove and the second groove.
2. In claim 1, A method for manufacturing a stacked heat exchanger for a fuel cell, characterized in that in the first step process above, a brazing filler is placed between the upper surface of the frame and the heat transfer plate.
3. In claim 1, A method for manufacturing a stacked heat exchanger for a fuel cell, characterized in that a plurality of guide holes are formed through the guide jig to guide the spot welding position.
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6. In claim 1, A method for manufacturing a stacked heat exchanger for a fuel cell, characterized in that in the third step process above, a brazing filler is placed between the bottom surface of the frame of the upper pre-assembly unit stack and the heat transfer plate of the lower pre-assembly unit stack among two pre-assembly unit stacks adjacent to each other.
7. A stacked heat exchanger for a fuel cell manufactured by the manufacturing method of any one of claims 1 to 3 and claim 6.

Description

Manufacturing Method of Layered Heat Exchanger for Fuel Cell and Layered Heat Exchanger for Fuel Cell Manufactured by the Same The present invention relates to a method for manufacturing a stacked heat exchanger for a fuel cell and a stacked heat exchanger for a fuel cell manufactured thereby. More specifically, the invention relates to a method for manufacturing a stacked heat exchanger for a fuel cell in which a heat transfer plate and a frame are temporarily fixed by spot welding to form a pre-assembled unit stack, and then the pre-assembled unit stacks are stacked in multiple stages and brazed, thereby preventing movement and warping of the parts and ensuring a uniform thickness of the joint area, and to a stacked heat exchanger for a fuel cell manufactured thereby. For reference, the present invention is the result of the following research project. - Specialized Research Management Agency: Pohang Technopark Foundation - Research Project Name: 2023 Support Project for Fostering Preliminary Hydrogen Specialized Enterprises - Research Project Title: Development of Manufacturing Technology for Heat Exchanger Components for 5kW SOEC Systems - Contribution rate: 100% - Organizer: FCI Co., Ltd. - Research Period: May 1, 2023 – November 30, 2023 Conventional solid oxide fuel cell systems are equipped with a heat exchanger for utilizing the heat of high-temperature combustion gases discharged from a fuel cell stack to preheat air, hydrogen gas, etc. One of the conventional heat exchangers is a plate-fin type heat exchanger having a structure in which plates and heat dissipation fins are alternately stacked. In the above heat exchanger, heat exchange occurs as fluid moves between the plates. The above heat exchanger is manufactured by alternately stacking plates and heat dissipation fins and then brazing them. Korean Registered Patent Publication No. 10-1369421 discloses a jig-integrated plate fin heat exchanger. The jig-integrated plate fin heat exchanger disclosed in the above-mentioned Korean Registered Patent Publication No. 10-1369421 comprises a bottom plate, support rods coupled to both ends of the bottom plate, plates inserted and stacked on the support rods with insertion holes formed at both ends, heat dissipation fins alternately stacked with the plates and having a cross-section in the shape of a square wave with an upper straight surface and a lower straight section, side bars that fix and support the heat dissipation fins at both ends and are inserted into the support rods with insertion holes formed in the center of each side bar, and a top plate inserted into the support rods through the insertion holes formed at both ends to apply pressure to fix the stacked plates and heat dissipation fins. In the jig-integrated plate fin heat exchanger configured as described above, a nut is fastened to the end of the support rod to bring the brazing plate and the heat dissipation fin into close contact. However, if nuts are fastened to the ends of the support rods as described above to bring the plate and heat dissipation fins into close contact, the fastening pressure may vary from nut to nut, making it difficult to ensure uniform contact across the entire surface of the plate and heat dissipation fins. Consequently, the non-uniform thickness of the joint between the plate and the heat dissipation fins reduces the dimensional accuracy of the product, and problems such as warping or separation of the joint surface occur as the base material deforms due to the heat applied during brazing. FIG. 1 is a perspective view showing a heat exchanger manufactured by a method for manufacturing a stacked heat exchanger for a fuel cell according to one embodiment of the present invention. FIG. 2 is a side cross-sectional view showing a heat exchanger manufactured by a method for manufacturing a stacked heat exchanger for a fuel cell according to one embodiment of the present invention. FIG. 3 is a planar cross-sectional view showing a heat exchanger manufactured by a method for manufacturing a stacked heat exchanger for a fuel cell according to one embodiment of the present invention. FIG. 4 is a perspective view showing a heat transfer fin of a stacked heat exchanger for a fuel cell according to one embodiment of the present invention. FIG. 5 is a flowchart illustrating a method for manufacturing a heat exchanger for a fuel cell according to one embodiment of the present invention. FIG. 6 is a cross-sectional view showing a pre-assembled unit stack manufactured by a method for manufacturing a heat exchanger for a fuel cell according to one embodiment of the present invention. FIG. 7 is a perspective view showing a pre-assembly jig in a method for manufacturing a heat exchanger for a fuel cell according to one embodiment of the present invention. FIG. 8 is a cross-sectional view showing a pre-assembly jig in a method for manufacturing a heat exchanger for a fuel cell according to one embodiment of the present invention.