基于末端负荷监测的变压差控制方法研究
Research on variable pressure difference control method based on terminal load monitoring
摘要：
由于空调水系统大部分时间在部分负荷下运行，提出了一种能够满足最不利热力末端需求的外网变压差控制策略，可以通过实时监测负荷调控末端的流量与压差。以某区域供冷供热系统为例进行研究，调研得到各末端用户的控制温差，实验测试确定了热力稳定时间。搭建了案例的环状管网水力模型，对比了定压差控制策略与变压差控制策略。结果表明，变压差控制策略使得末端用户阀门开度保持在90%左右，相较于定压差供回水温差提升了1 ℃，水泵的输配能耗减少了24.8%，有效实现了节能减排。
Abstract：
Since the air conditioning water system always runs under partial load, a pipeline network pressure difference control strategy is proposed, which can meet the most unfavorable thermodynamic terminal demand. It can detect the required flow and pressure difference of all the terminals through real-time load monitoring. This method is applied to a district cooling and heating system. The best operating temperature difference of each terminal is obtained by investigation, and the thermal stability time is determined by the experimental test. A hydraulic model of the loop pipe network of the case is built, and the constant pressure difference and the variable pressure difference control strategies are compared. The results show that the variable pressure difference control strategy keeps the valve opening of the terminal at about 90%. Compared with the constant pressure difference control strategy, the temperature difference between supply and return water increases 1 ℃, the energy consumption of the distribution system of water pumps decreases by 24.8%, which effectively realizes energy conservation and pollution emission reduction.
Keywords:district cooling and heating system; terminal load monitoring; variable pressure difference control; most unfavorable thermodynamic terminal; flow; pressure difference; thermal stability time; energy conservation