Experimental study on characteristics of a flow control valve in chilled water system

 In order to solve the high energy consumption problem of chilled water pump caused by excessive flow rate of chilled water at low load, proposes a new control strategy for flow control valves. Sets up a simulation test bench, compares the valve opening, chilled water flow rate, temperature difference between supply and return water and chilled water pump power of air conditioning chilled water system at different air rates and water supply temperatures. Verifies the control characteristics and energy saving effect of this control valve. The results show that the valve controls the return water temperature better, and when the room load is less than the maximum cooling capacity of the fan coil unit (FCU), the control valve can effectively adjust the chilled water flow rate, improve the temperature difference between supply and return water, and reduce the power consumption of chilled water pump. When the supply water temperature is 7 ℃, the average temperature difference of supply and return water is 4.79 ℃, 4.39 ℃ and 4.97 ℃ at low (325 m3/h), medium (500 m3/h) and high (600 m3/h) air rates, respectively. Compared with the on-off valve in same conditions, average chilled water flow rate decreases by 47.71%, 39.07% and 31.28%, respectively, and the energy consumption of chilled water pump decreases by 12.20%, 11.31% and 10.66%, respectively. When the air rate is at medium and the temperature of supply water is 7 ℃, 8 ℃ and 9 ℃, the average temperature difference of supply and return water is 4.39  ℃, 3.56 ℃ and 3.33  ℃, respectively. Compared with the on-off valve, the average chilled water flow decreases by 39.07%, 11.35% and 18.21%, respectively, and the energy consumption of chilled water pump decreases by 11.31%, 5.09% and 7.78%, respectively.