Water-cooled expansion unit is a new generation of high-efficiency and energy-saving products designed and developed for biomedicine, cold chain logistics, food processing, plant air conditioning and other places. The product has a wide range of applications and is divided into 5~32℃ air-conditioning series and -30~5℃ freezing and refrigerating series according to the temperature. The unit adopts high-reliability scroll compressor and new type of high-efficiency elliptical tube heat exchanger, which has the advantages of stable performance, reliability, high energy-efficiency ratio, simple and beautiful appearance structure, compact size and easy and flexible installation, etc., and it is the ideal choice for users.