Operation Analysis of Large High Back Pressure Cogeneration Unit in Heating Season
The cold end loss of the thermal power plant is the largest energy loss of the thermal system of the power plant.A large amount of steam turbine condenser waste heat was discharged into the atmos-phere through different cooling equipments.In order to reduce the cold end loss of the unit,two 350 MW cogeneration units of a power plant were taken as an example to establish a high back pressure waste heat step-heating model and carry out a study on the high back pressure heating retrofit of the unit.Combined with the temperature change of the periodic supply and return water in the heating season,the extraction and load distribution modes of the double extraction condensation mode(EC-EC)and the double extrac-tion-high back pressure mode(EHBP-EHBP)in the heating season were studied.The economic and thermodynamic performance of the heating unit was analyzed by using the calorimetric method and exergy analysis method.The results show that the average power generation of the high back pressure tandem u-nit is 26.2 MW higher than that of the extraction condensing unit in the heating season,and the average standard coal consumption of power generation is reduced by 92.0 g/(kW·h),and the thermal economy is better.During the heating season,the steam-water exergy efficiency of the high back pressure tandem unit is 9.6％higher than that of the original extraction condensing unit on average,and the exergy effi-ciency is increased by 9.4％under the rated heating condition.
combined heat and power generationhigh back pressureheating season operationecono-myexergy efficiency
万方数据
维普
