Some conditions that need to be met before the calculation of the plate heat exchanger
The two mediums of the plate heat exchanger perform cold and heat exchange. In the working condition that the two mediums do not change in phase state, before the selection calculation, some conditions that the plate heat exchanger needs to meet are generally required to operate.
1. The convective heat transfer coefficient of the two mediums in the plate heat exchanger and the total heat transfer coefficient of the plate heat exchanger can be regarded as constants along the heat exchange surface;
2. The heat loss of the plate heat exchanger during the heat exchange process is negligible, because in the heat exchange process, the heat loss is unavoidable, and the heat loss is very little in the normal heat exchange process , can be ignored;
3. When the flow rate of the plate heat exchanger in the fluid channel is evenly distributed, it is considered that the axial pressure gradient in the corner hole box is 0;
4. The additional pressure drop generated by the plate heat exchanger under multi-process conditions can be ignored;
5. The local pressure drop when entering from the inlet of the plate heat exchanger and exiting from the plate channel of the plate heat exchanger should be included in the pressure drop along the way.
