The capacity of a chilled water pump is usually designed based on the maximum temperature and occupancy rate, with a margin of 10% to 20% left on this basis. The water pump system operates at a fixed maximum water flow rate for a long time. Due to the large changes in seasons, day and night, and occupancy rates, the actual thermal load of the central air conditioning system in Figure 1 is much lower than the design load for most of the time. Compared with the maximum design load (load rate of 100%) that determines the flow rate and pressure of the water pump, the operating time with a load rate below 50% is nearly half of the year. Generally, the design temperature of the chilled water is 5-7 ℃, but in fact, the temperature of the chilled water is only 2-4 ℃ for most of the year, which means that the water pump is operating at full power, increasing pipeline energy loss and wasting the conveying energy of the water pump operation. This leads to ineffective use of energy, while automatic flow regulation and significant energy savings can be achieved through variable frequency speed regulation technology.