Chilled water precision air conditioner and energy-conservation control method thereof

The invention discloses a chilled water precision air conditioner and an energy-conservation control method thereof, wherein the chilled water precision air conditioner comprises a chilled water precision air conditioner unit, a control cabinet connected to the chilled water precision air conditioner unit, a return-air temperature sensor arranged in the chilled water precision air conditioner unit, a speed-adjustable draught fan, chilled water valves, a chilled water coil pipe, a chilled water pipeline connected to the chilled water precision air conditioner unit and a chilled water pump. When the cooling capacity demand is increased, the bigger chilled water valve is controlled to open firstly by the control cabinet, and secondly the revolving speed of the speed-adjustable draught fan is improved; when the cooling capacity demand is decreased, the revolving speed of the speed-adjustable draught fan is lowered firstly, and the small chilled water valve is closed secondly. The chilled water precision air conditioner and the energy-conservation control method thereof have the advantages that the defects that the energy conservation of the whole system entirely depends on whether the frequency of a chilled water system of a user is convertible or not and the resistance change of the water pipeline exerts influence on the whole water system energy conservation when the open of the water valves changes in a traditional method of adjusting the open of the water valves only are overcome, and error control and inaccuracy from discharge variation to differential pressure variation are avoided furthermore.