Assessment Of Energy Saving Potential And Energy Diagnosis On 600MW Subcritical Air Cooling Coal-fired Power Unit

In recent years,the voice of energy conservation and emissions reductuion is high.The “13th national five-year plan” of electric powder development puts forward higher requirement on the energy consumption level of coal unit.In the period of “13th national five-year plan”,our country implement energy-saving reconstruction of 340 million kilowatts,and try to eliminate backward unit of 20 million kilowatts.Until 2020,when the average power coal consumption rate of coal unit in active service fell to 310 grams standard coal per kilowatt,ultra-low emission will realize on qualified units above 300 thousand kilowatts.In this paper,unit of a certain power plant is selected as the object to research the practical problems of high power supply coal consumption rate.The whole thermal performance of unit is checked and calculated based on the operation and desigh data under different working conditions,and a more accurate thermal performance model is established.The standard and consumption difference analysis is proceed on the base of model,and the reason for the high energy consumption is confirmed.In addition,the service-power consumption rate is analysed,and the suggestions of changing elecric pump to steam pump are put forward,and the effect and economy of energy saving are analysed in this paper.In order to further reduce the coal consumption of unit level,the two kinds of reconstructive measures of improving the reheating temperature and adding rush condenser are discussed,and the two measures are carried saving energy and reducing consumption assessment using the thermodanamic methods.After thermal performance analysis,some preliminary constructive conclusions are drawn: the main cause of the high unit coal consumption rate is the low flow efficiency of the steam turbine low pressure cylinder,and the influence of the side of the boiler and the backwater heating side on the unit energy consumption is not big.Changing electric pump to steam pump could reduce the service-poer consumption rate,however,this measure has slight influence on steam turbine low pressure cylinder efficiency.Improving the main steam temperature and reheat steam temperature could greatly reduce the power supply coal consumption rate,but transformation quantity is very large.The cost performance of adding rush condenser is the highest and the unit efficiency could be improved by means of reducing the bace pressure in summer high temperature time.The research results in this paper lay a scientific theory foundation of achieving the energy-saving renovation and efficient operation of subcritical air cooling unit,and have the practical guiding significance to the similar unit energy saving reconstruction.