变频调速恒压与变压供水的能耗分析

Energy consumption analysis on constant-pressure variable-frequency water supply and variable-pressure variable-frequency water supply

研究了恒压和变压两种供水方式的能耗。采用图示法对比了水泵全速、恒压和变压运行的能耗差别,分析了管网特性的静扬程随水泵工况变化的关系。基于某泵站水泵运行数据、运行图、变速状态下流量和泵效的关系得出了转速及流量与百吨水能耗的变化趋势,发现恒压供水调速、调流范围小,小流量供水时能耗趋势上升,而变压供水调速、调流范围宽,小流量供水时能耗趋势下降,并从变速范围、水泵高效区范围和百吨水能耗指标3个方面对比了恒压供水与变压供水的优劣,结果表明变压供水比恒压供水能降低能耗20%以上。

The energy consumptions of constant-pressure water supply and variable-pressure water supply are studied. The energy consumptions of constant-pressure and variable-pressure running with pump＇s full-speed are compared with diagram. The static head change of network characteristics with pump＇s running condition is analyzed. Based on a pump station＇s running data, the running diagram, the relation of pump efficiency, flow under variable speed, the relation of energy consumption per 100 m^3 and rotating speed are obtained. It is found that constant-pressure water supply has the smaller variable ranges of rotating speed and flow rate, the energy consumption at small flow rate increases, and the variable-pressure water supply has the larger variable ranges of rotating speed and flow rate. The advantages and disadvantages of pump constant-pressure and variable-pressure water supply are compared from three aspects of variable-speed range, pump＇s high-efficiency field and energy consumption. The conclusion is obtained that the energy consumption of pump variable-pressure water supply is 20% lower than that of pump constant-pressure water supply.