Air source screw heat pumps are used in 50,0000m2 central heating project. The heating capacity of single unit under standard condition is 620kw. The project adopts the distributed central heating mode, and there are two energy stations. No.1 energy station adopts the ground type installation, No.2 energy station adopts the frame type layered type. 63 sets of Hanbell LT-S-A series ultra-low ambient temperature two-stage heat pump compressors are used. During the heating operation from 2016 to 2018, all the 63 sets of equipments run smoothly. The indoor temperature of high-rise buildings reaches 22-26℃, and the temperature in villa reaches 20-22℃. The user feedbacks that the effect is good.