Taking 135MW heating unit as an example: When steam turbine VWO condition is in summer, steam condensing capacity of steam turbine is 324.17t / h and circulating capacity of one unit is 19640t / h; when steam turbine rated extraction condition, Steam condensate volume of 223.36t / h, a unit of 12274 t / h of circulating water; steam turbine at maximum extraction conditions, condensing steam turbine capacity of 142.66t / h, the unit of circulating water is 4700 t / h. Circulating water system flow from 4700t / H - 19000T / H changes, according to the conventional capacity of the pump is arranged to meet the minimum heat load of the cooling water unit configuration circulating pump flow 9800T / H-11700T / H, water supply head about 18.0- 21.5 meters, two pumps run in parallel. In the rated extraction conditions, a pump running, due to the reduction of circulating water, the system's water resistance drops, the pump flow 12274T / H, head will drop to 15.0-16.0 meters, the steam turbine in the maximum extraction conditions, To meet the requirements of circulating water system to run a pump, due to a substantial reduction in water supply, the pump head greatly increased, resulting in a cooling tower water directly to increase the water flow device with a sink, water flow in the filler on the heat exchange The reduction of time reduces the cooling effect of the cooling tower. Of course, the effect of reducing the heat exchange between the filler and the filler does not draw too much attention in the winter, but the pump operation will definitely move out of the efficient range of the pump. The working efficiency of the pump is reduced and the reactive power of the motor is wasted. As circulating pump motor power 710KW, long-term operation is not conducive to power plant energy conservation. In this case requires a new pump configuration mode, it is necessary to meet the large flow, high lift requirements but also to meet the low flow requirements of low lift, large and small pumps and high and low speed mode of operation. This configuration mode emphasizes large pumps high flow, high speed in accordance with the system maximum flow of choice, water flow and head to meet the system requirements. Small pumps, high flow rate, high speed in accordance with the system flow of 60% of the choice, as a large pump standby pump; Large pump low flow, low speed selection Small pumps in accordance with the high flow rate, high speed selection, as a small pump high-speed backup Pump; small pump low flow, low speed in full accordance with the system minimum flow, and system requirements of the supply lift choice, this time no other spare pump. This pumping unit through the changes in conditions, automatically adjust the pump size, small and high-speed pumps, low-speed operation, the pump water supply basically meet the requirements of the system of circulating water. 2 efficient use of energy-saving circulating pump Shandong Shiliquan Power Plant 2 125MW unit is equipped with four 48SH-22 with the same type of circulating pump operation. Most of the time in a year there is a single water supply system does not run enough water supply flow, 2 sets of parallel operation of the pump power plant has increased too much, the inefficient pumps affect the economic operation of the unit. In October 1998, the 4 # pump (48SH-22) was replaced with the G48SH high-efficiency energy-saving pump. After the high-efficiency energy-saving pump was put into operation, the power plant commissioned the Guangdong Electric Power Research Institute to conduct the energy-efficient pump performance test. The test results show that: The actual operating efficiencies at high and low speeds were as high as 87.78% and 86.11%, respectively, which were 28.26% and 26.5% higher than those of the other unopened 48SH-22 pumps respectively. The power consumption was significantly reduced and the operation of the new pump was flexible. Two sets of 125MW units in Yunfu Power Plant in Guangdong use a secondary circulation water supply system. Four 48SH-22 circulating pumps of the same type are arranged in the system. The operation modes of the pumps are three pumps in summer and two in other seasons. Because of the low flow rate and low efficiency of a single pump during operation, the circulating pump was changed into an efficient G48SH pump in June 1998. High efficiency G48SH pump put into operation, the power plant commissioned the Guangdong Electric Power Research Institute of the new pump efficiency test, the test results show that: the new pump at high speed flow of up to 16537t / h, the actual operating efficiency as high as 87.78%, the motor power 1002KW; Low-speed flow of 13080t / h, the actual operating efficiency of 86.12%, the motor power 646KW, pump operating conditions and operating conditions basically consistent with the unit. The actual operation of the original pump flow 14400t / h, efficiency 59.62%, motor power 1089KW; maximum efficiency of 70% when the flow of 11540t / h, pump operating conditions and operating conditions do not match the unit. This shows that the new pump 2117 t / h larger than the old pump, high efficiency, the motor power is low 87.7KW; new pump low speed operation of a single pump saves 443KW per hour. In December 1998, the Ministry of Science and Technology of the former Ministry of Power Industry organized the appraisal and awarded the appraisal certificate of science and technology achievements throughout the country. 3 Conclusion Of course, the promotion of any new technology requires a cognitive process, the most important feature of energy-efficient water pump is energy saving, high efficiency. However, whether it is suitable for all regions, all 135MW units operating conditions also need more practical proof of application, but also the choice of local conditions. Promote energy-efficient circulating pump not only involves the configuration of the circulating pump in the power plant, pump standby and pump operation costs, but also relates to the interlock control of pump and turbine operation, etc., especially in the Yangtze River water pump room must be carefully selected, efficient Energy-saving circulating pump geometry than the larger capacity of the pump is much larger, for the waterfront pumping station, equipment and equipment operating costs less than the structure and cost of water pumping station construction costs, especially the water source water level and the highest water level difference between the larger when.