Plate heat exchanger maintenance: how to change the resistance of plate heat exchangers? _
267 plate heat exchanger has the characteristics of high heat exchange efficiency, small heat loss, compact and lightweight structure, small footprint, wide application, long service life and so on. A few days ago, a friend asked me about the resistance of plate heat exchangers. Today, I will share with you the maintenance of plate heat exchangers: how to change the resistance of plate heat exchangers? 1. Using the thermal mixing board The thermal mixing board has the same corrugated geometric structure on both sides. The plates are divided into hard board (H) and soft board (L) according to the angle of the herringbone corrugation. The included angle (usually about 120 degrees) Greater than 90. 2. Asymmetric plate heat exchanger is used. A symmetric plate heat exchanger is composed of plates with the same corrugated geometry on both sides of the plate, forming a plate heat exchanger with equal cross-sectional areas of the cold and hot runners. Asymmetric (unequal cross-sectional area) plate heat exchangers change the wave geometry of the two sides of the plate according to the heat transfer characteristics and pressure drop requirements of the cold and hot fluids to form a plate heat exchanger with unequal cross-sectional areas of the cold and hot runners , The diameter of the corner hole on the wide runner side is larger The heat transfer coefficient of the asymmetrical plate heat exchanger decreases slightly, and the pressure drop is greatly reduced. When the flow of cold and heat medium is relatively large, the use of an asymmetric single-process heat exchanger can reduce the plate area by 15%-30% compared to a symmetrical single-process heat exchanger. 3. Set the bypass pipe of the plate heat exchanger. When the flow of cold and heat medium is relatively large, a bypass pipe can be installed between the inlet and outlet of the heat exchanger on the side of the large flow to reduce the flow into the heat exchanger and reduce the resistance. In order to facilitate adjustment, a regulating valve should be installed on the bypass pipe. This method should adopt a countercurrent arrangement to make the temperature of the cold medium exiting the heat exchanger higher, and to ensure that the temperature of the cold medium after the outlet of the heat exchanger merges can meet the design requirements. The advantage of setting the bypass pipe of the heat exchanger is to ensure that the heat exchanger has a higher heat transfer coefficient and reduce the resistance of the heat exchanger, but the disadvantages are slightly complicated to adjust. 4. Adopt multi-process combination, adopt multi-process combination layout, and adopt more processes on the side of small flow to increase the flow rate and obtain higher heat transfer coefficient. On the large flow side, fewer processes are used to reduce the resistance of the heat exchanger. The editor of the above article shared with you the maintenance of plate heat exchangers: how to change the resistance of plate heat exchangers? If you have any questions or needs about the maintenance of the plate heat exchanger, the official website of Diguang Heat Transfer welcomes your consultation.