变频驱动器（VFD）已广泛应用于冷冻水泵和加热热水泵，以满足建筑供暖、通风和空调（HVAC）系统中的可变负载。然而，由于电机在较低转速下过热，带VFD的泵的最低转速接近额定转速的30%。因此，当系统负载低于设计条件的30%时，它们必须以最小功率和流速运行，以覆盖大部分小时。如果泵能够在较低的速度下有效运行，则在这些小时内，泵功率可能低至额定功率的1%，这将导致最小泵功率约为额定功率的10%。 提出了一种称为多泵尺寸VFD的新配置。增加了一台带VFD的低容量泵，以满足低负荷的工作时间，并在泵送系统中保持恒定的回路压差。它可以显著降低泵的能耗。作为案例分析，对一栋每天24小时、每周7天运行的实验室大楼和一栋医院大楼进行了分析，结果表明，采用新配置和1。 5到7.1年的简单回报。引用:2020年虚拟会议技术论文

Variable-frequency drives (VFDs) have been widelyapplied to chilled-water pumps and heating hot-water pumpsto meet variable loads in building heating, ventilation, and airconditioning(HVAC) systems. However, pumps with VFDshave a minimum speed near 30% of rated speed due to themotor overheating at lower speeds. Thus, they have to run atthis minimum power and flow rate to cover a large percentageof hours when the system loads are below 30% of the designedcondition. This results in a minimum pump power of ~10% ofrated power when the pump power could be as low as 1% ofrated power during these hours if the pump were capable ofoperating effectively at lower speeds. A new configurationcalled multiple pump sizes with VFD is proposed. A lowercapacity pump with a VFD is added to cover the operatinghours with lower loads and maintain a constant-loop differentialpressure in the pumping system. It can significantlyreduce pump energy consumption. A laboratory building anda hospital building both running for 24 hours per day, 7 daysper week are analyzed as case studies, and results show 10.5%to 32.1% pumping power energy savings with the new configurationand 1.5 to 7.1 year simple payback.