HCWZ water-cooled/evaporative-cooled medium-low temperature semi-closed piston chiller is a new generation of chiller unit specially developed to meet the demand of small cooling capacity cold source. The unit can provide -37~12℃ refrigerant carrier, compact structure, small footprint, convenient control and operation, suitable for pharmaceutical, chemical, metallurgy, electronics, food and other industries in the production process, can also be used as a small and medium-sized cold storage cold source host. This series of units have a wide range of applications, and the cold capacity of the low and medium temperature units ranges from 30.5kW to 305.6kW; and a variety of refrigerants can be selected, such as R22, R407C, R404A, R507A, in order to meet the different needs of users.