Views:0 Author:Site Editor Publish Time: 2020-08-18 Origin:Site
The detachable plate heat exchanger is made of many heat exchange plates (metal thin plates stamped with corrugated grooves), which are sealed by sealing gaskets at a certain interval and compressed by clamping studs. The holes in the corners constitute A continuous channel. The medium enters the channel from the inlet and is distributed into the flow channel between the heat exchange plates. Each plate has a sealing gasket. The positions between the plates are alternately placed. The two fluids are respectively Enter the respective channels and are separated by plates. Under normal circumstances, the two media flow countercurrently in the channels. The heat medium transfers heat energy to the plates, and the plates transfer heat energy to the cold medium on the other side to reach the heat medium. The temperature is lowered to be cooled, and the temperature of the cold medium rises for the purpose of heating.
Features of plate heat exchanger:
1. High heat transfer coefficient;
Since different corrugated plates are turned upside down to form a complex flow channel, the fluid flows in three-dimensional rotation in the flow channel between the corrugated plates, which can produce turbulent flow at a low Reynolds number (generally Re=50~200), so heat transfer The coefficient is high, generally considered to be 3 to 5 times that of the shell-and-tube type.
2. The logarithmic average temperature difference is large, and the terminal temperature difference is small.
In the shell-and-tube heat exchanger, the two fluids flow in the tube side and the shell side respectively, and the flow is generally cross-flow, and the logarithmic average temperature difference correction coefficient is small, while the plate heat exchanger mostly uses co-current or counter-current flow. , The correction coefficient is usually about 0.95. In addition, the flow of cold and hot fluids in the plate heat exchanger is parallel to the heat exchange surface without bypass flow, so the temperature difference at the end of the plate heat exchanger is small, and the water heat can be exchanged. Below 1℃, while the shell-and-tube heat exchanger is generally 5℃.
3. Small footprint.
The plate heat exchanger has a compact structure. The heat exchange area per unit volume is 2 to 5 times that of the shell and tube type. Unlike the shell and tube type, there is no need to reserve a place for maintenance of the tube bundle. Therefore, the same heat exchange is achieved. The heat exchanger covers an area of about 1/5~1/8 of the shell-and-tube heat exchanger.
4. Easy to change the heat exchange area or process combination;
As long as you add or reduce a few plates, you can achieve the purpose of increasing or reducing the heat exchange area; changing the plate arrangement or replacing a few plates can achieve the required process combination and adapt to the new heat exchange conditions. The heat transfer area of the shell heat exchanger is almost impossible to increase.