利用双温度控制阀降低冷水系统能耗
Energy efficient chilled water system with dual-temperature modulating valves
摘要：
末端为风机盘管的集中空调冷水系统常出现“大流量、小温差”问题，导致水泵能耗增加。单纯依靠管网水力平衡或水泵变频控制并不能解决这一问题，必须从末端的控制入手。分析了传统的通断调节和连续调节存在的问题，在此基础上提出了通断调节与连续调节相结合的控制策略，并基于这种控制策略开发了双温度控制阀。该阀门根据回水温度来选择运行模式，在保证室温调节质量的基础上兼顾室内相对湿度，同时提升供回水温差，实现水系统节能。双温度控制阀采用串级调节回路，增强了控制过程的抗干扰能力。利用冷水系统动态模拟平台进行了模拟实验，验证了双温度控制阀的控制效果和节能潜力。
Abstract：
Chilled water circulation systems with fan coil units commonly suffer from low delta-T syndrome, increasing the pump power consumption. This problem cannot be solved merely by hydraulic balance or pump variable speed control. The control strategy of water valve of fan coil units must be improved. Analyses the features of traditional control strategy, including continuous control and on-off control. Presents a new control strategy, which combines the advantages of continuous control and on-off control. Based on this strategy, the dual-temperature modulating valve is developed. This valve chooses its control mode according to the return water temperature. It can maintain room air temperature at set point and keep room air relative humidity within proper range, meanwhile increase water temperature differential and save pump power. The dual-temperature modulating valve uses cascade control loop to increase its capacity of resisting disturbance. Performs simulation tests on the dynamic simulation platform of chilled water system to test the control effect and energy-saving potential of the dual-temperature modulating valve.
Keywords:chilledwatersystem,lowdelta-Tsyndrome,fancoil,dual-temperaturemodulatingvalve,cascadecontrol,energysaving