This paper introduces the characteristics of a new type G series circulating water pump based on the high efficiency and energy saving of circulating water pump and gives the key explanation with the application of G48Sh new circulating water pump in the design of 135MW unit. G48Sh new circulating pump design parameters and plant circulating water system, the actual resistance parameters and kiss, the pump running more efficient. More than 100 G48Sh circulating pumps put into operation were sampled and tested. The actual efficiency of G48Sh pumps was 84-88%. Compared with the conventional mode of 135MW units, the actual efficiency of one machine with two pumps of the same model 48Sh-22 was improved 25%. G48Sh new circulating pump with motor using bipolar number, double speed operation. According to the annual season different steam turbine condenser cooling water volume changes drastically, by adjusting the motor motor pole number and speed motor output power changes, so that the circulating pump water supply, water pressure changes. Increased the flexibility of the system adjustment, to minimize plant electricity load. For example, a G48Sh high-efficiency energy-saving pump runs in high speed in summer and 3000 tons / hour more than two 48Sh-22 pumps at the same pump power. In winter, one G48Sh high efficiency energy-saving pump runs at low speed, Under the condition that the system water supply is quite high, the power of the pump equipped motor is reduced from 1080KW to 680KW, the power drop is over 30%, equivalent to 2.3 million kWh saved per pump per year. The introduction of G48Sh high efficiency and energy saving circulating water pump optimizes the hydraulic conditions of the circulating water system and widens the variation range of the high efficiency section of the water pump so as to ensure the actual operating efficiency of the circulating water pump at two different rotational speeds not less than 85% The efficiency of work. The introduction of the G48Sh high efficiency and energy saving circulating water pump has changed the conventional design concept of capacity configuration mode of two turbines with two circulating pumps (hereinafter referred to as "one machine and two pumps") and proposed the design concept of large capacity and small pump configuration. Large pumps have high speed, low speed, small pumps also have high speed, low speed, which combined a variety of pump operating conditions, and each other standby. Basically meet the steam turbine working conditions change conditions. High efficiency and energy saving circulating pump horizontal pump casing, operation, maintenance is very convenient. Efficient energy-saving circulating pump configuration In Jinchuan Thermal Power Plant in Gansu, Shandong Huatai Thermal Power Plant, Shandong Liyan Power Plant, Xuzhou City Power Plant and Shandong Binzhou Weiqiao Thermal Power Plant, we have designed 18 135MW unit domestic EHV, intermediate reheat units. These power plants have a common characteristic, basically enterprises spontaneous use, enterprises in addition to a stable power demand but also have a certain heating load, heating load fluctuations in large enterprises. Making the circulating water system in the power plant circulating water drastically changed. In the absence of heating load, the heating unit is basically operating in pure condensing conditions, which often occur in the summer of each year. With the advent of winter, the heating load and living heating load increase, so that the unit heating load greatly increased, in extreme cases, the unit will exceed the rated pumping conditions. Most of these enterprises are located in North China, Northeast China and Northwest China, heating longer, with a fixed heating period of 4-6 months each year, a few years longer heating period. For such a long period of time, the unit operates with steam extraction and heating, which makes the circulating flow of power plants run at a lower time for a long time. Considering the long-term economic operation requirements of power plants, the water supply flow of the circulating pump and the high efficiency range of the lift are very long.