集中空调冷却水变流量问题辨析

Variable cooling water flow in central air conditioning systems

指出集中空调冷却水系统为开式系统,一般不适用功率三次方定律,静压头应为冷却塔塔体扬程,并提出了冷却水泵变速时轴功率的计算公式;明确变流量的节能效果与控制方式密切相关,即使机组处于满负荷状态,但只要是在非设计工况,采用冷凝温度控制法,也可能实现变流量节能;指出制定多台冷水机组部分负荷性能指标的意义。

Points out that the cubic law of pump power is not valid for the cooling water system of central air conditioning for it is an open system. The static head should be the lift in a cooling tower. Presents the formula for computing power of the variable speed pump in cooling water systems. Makes it clear that the effect of variable water flow on energy saving depends on control mode. There is still room for energy saving with condensing-temperature control as long as the chiller operates off the design condition even in full load. Points out the importance of setting a standard for multi-chiller performance.