1. Calculation calculation: Contrary to the planning calculation, the heat exchange area and flow channel layout are known, and the flow rate of cold and hot fluids and the inlet and outlet temperatures are also known values. It needs to be calculated under the channel layout plan whether the fluid outlet temperature reaches the predetermined target and whether the pressure drop meets the required value.
       2. Design calculation: Generally, the flow rate of the fluid on both sides and any three of the four inlet and outlet temperatures are given, and it is necessary to calculate the effective heat transfer area and arrangement and combination of processes and channels under certain pressure constraints.
       The above two different types of accounting are based on the same principles, but there are big differences in the accounting methods or processes. In fact, when doing engineering planning for a certain heat exchange site, both types of calculations are often used. That is, first use the planning calculation algorithm to calculate the heat exchange area and channel layout, and then use the verification calculation program to determine whether the area and layout can complete the predetermined heat exchange task.