Small water-cooled chillers with casing water-cooled condenser, can be used pickling. The specific method of operation is: remove the condenser, release the water, and then into the customs into the 10% dilute sulfuric acid solution, until the outlet has a solution outflow position. Dilute sulfuric acid in the condenser to stay 20 ~ 30min after the release, so repeated two or three times, and finally installed cooling pipe and condenser connection tube, open the cooling valve rinse 10 ~ 20min, anti-scaling and cleaning work is over.