system A new air-conditioning system with chilled water storage is provided, as shown in Fig. 2. Water back from users is divided into two flows by separator, one is mixed with chilled water out of storage unit and is as chilled water supplied for users, and the other one is back to the storage tank, which flux rate is equal to chilled water out of tank.With this configuration, chilled water can be adjusted to different temperature to meet the need of different users or loads,and also the valve linked to storage tank can be protected by less pressure difference resulting from part of water back.