Huai' An Power Plant Motor-driven Feedwater Pump Frequency Conversion Retrofit And Energy Efficiency Analysis

In recent years,a serious environment problem such as environmental resources drying up,the pollution and the global warming caused by emissions of greenhouse of of gases has aroused wide attention.The energy saving policy has become one of the important national policy of China.The thermal power installed capacity is still dominant in China's power structure.Thermal power plants plays an important role in the energy system,but it also costs a large power consumption,including coal consumption and the auxiliary power consumption rate.Electric feed-water pump power consumption accounts for about 20~30% power plant auxiliary power.Therefore,energy conservation transformation of the feed-water pump has important significance on reduce the rate of power plant auxiliary power and coal consumption.The generating unit of the Huai'an thermal power plant is the 2×330MW coal direct air-cooling heating unit.The water supply system is configured with 3 hydraulic coupler speed regulated feed-water pumps,whose capacity is 50% BMCR.Two of pumps are in the standby state while the other is moving in normal operation modes.The feed-water pump have great energy saving potential because of its large power consumption.Therefore,this paper mainly concentrate on the corresponding feed water pump frequency conversion energy-saving reform strategy for the Huai'an thermal power plant,and the following studies were conducted:1)Embark from the basic characteristics of feed-water pump,the paper analyzes the basic principles of the feed water pump speed regulation technology.On the basis,the principle,applications,advantages and disadvantages of different kinds of motor speed control method are analyzed and discussed.Through the comparison of the energy transfer efficiency and technical performance,it can be seen that frequency control methods has significant advantages over the other speed regulation methods in aspects of energy saving and technical/economic characteristics.2)The main job is investigating and surveing practical cases of frequency-conversion of feed-water pump in this chapter.Take Maliantai power plant that has finished converting as a reference,and start from power consumption of pump before and after reconstruction,reliability of frequency conversion,the conversion of hydraulic coupler and control system to analyse the feasibility of frequency conversion in Huaian thermal power plant.3)This chapter starts from the modification scheme of electric water pump frequency conversion oandf energy saving in Huaian power plant,analyzes respectively model selection,technical requirement and parameter configuration of frequency conversion device.On this basis,according to the actual situation of feed water pump in Huai'an power plant #1 and #2 unit.The selection of the frequency conversion equipment,the cooling scheme,the power supply,grounding scheme and the implementation of the transformation of frequency conversion are completed.Finally,the energy saving effect is analyzed by comparing the experimental data before and after the transformation.The simulation results verify the correctness and effectiveness of the proposed schemes in this paper.