Cleaning method of cooling side of plate type heat exchanger

The invention discloses a cleaning method of a cooling side of a plate type heat exchanger and relates to an impurity removing method of the plate type heat exchanger. The cleaning method is characterized in that the cleaning process comprises the following steps of: introducing acid-washing liquid into the cooling side of the plate type heat exchanger for soaking and then discharging soaked and removed impurities along with the acid-washing liquid. The cleaning method disclosed by the invention has the advantages that the cooling side is cleaned by using weak acid without containing CI, so that the effect is obvious; after cleaning, the operational cycle of the plate type heat exchanger is obviously prolonged, the labor intensity of employees is obviously reduced, the equipment damage rate is greatly reduced, and the cost of spare parts and the cleaning cost are greatly reduced; and the heat exchange effect is very obvious, and the refined-liquid cooling temperature and the mother-liquid rising temperatur