The first thing is to know the parameters, the first medium, what media are on both sides, temperature and pressure. If it is an ordinary liquid (water, oil, etc.). ), basically can use plate heat exchanger, if it is soda ash, generally shell-and-tube heat exchanger, if it is coking industry, generally spiral plate heat exchanger, and some pharmaceutical industries need to use fully welded plate heat exchanger. After selecting the type, it depends on the medium and what material is needed. Generally, there are many plate heat exchangers 304,316,316l, and there are also titanium plates, copper plates and graphite plates. Shell and tube plates are generally made of the same material and many kinds of materials, and spiral plates are generally made of many kinds of materials like pipes, and then calculated by data (your basic calculation is the whole calculation, that is, those items). Now it is generally software calculation and selection.