In the industrial production of petroleum, chemical, light industry, pharmaceutical, energy, etc., heat exchangers are often used to heat low temperature fluids or to cool high temperature fluids, vaporize liquids into steam or condense steam into liquids. The heat exchanger can be either a unit device such as a heater, a cooler and a condenser, or a component of a process equipment such as a heat exchanger in an ammonia synthesis column. Heat exchangers are important unit equipment in chemical production. According to statistics, the tonnage of heat exchangers accounts for about 20% of the entire process equipment and even up to 30%. The importance of this is conceivable.