Research On Through-flow Reconstruction For Steam Turbine At Linhe Power Plant

In response to the national policy of energy conservation and emissions reduction,through-flow of 300 MW steam turbine at Linhe power plant was taken as an example,the causes of heat consumption increases were found out by making thermal performance test and analyzing history operation data;then,according to the results above,optimization measure was put forward to reconstruct through-flow of steam turbine;finally,the technical and economic performance of through-flow reconstruction was analysed by comparing the data of thermal performance test before and after reconstruction.The results show that: due to large throttling loss and part of the shaft seal leakage amount,steam turbine cylinder efficiency is low,which have a greater influence on the unit economy;the best reconstruction scheme(the main steam pressure and main and reheat steam temperature to keep the original design,improve the nameplate output)and the corresponding technical measures are determined by analysing various retrofit scheme;compared with reconstruction before,the thermal performance of unit improves sharply,and coal consumption of unit decreases 7.1g/(kW?h),11.9g/(kW?h),9.5g/(kW?h)respectively under in 100%THA,75%THA,50%THA working condition.In the case that the unit works under 100%THA and output 1.68 billion kW?h throughout year,the unit can adds 3.487 million yuan of revenues from coal-saving,and the rate of return on investment of reconstruction project is 7.7%.