Research And Performance Analysis Of High-Back-Pressure Heating Reformation Of 350MW Supercritical Unit

With the carrying out of ultra-low emissions and energy-saving transformation for coal-fired power plants,as well as the opening of the carbon trading market,energy conservation and emission reduction has become an inevitable trend for thermal power industry.Supercritical and ultra-supercritical high-capacity units have great advantages in energy conservation and emission reduction,resulting in the loss of living space for small and medium-capacity units,the unit of 300 MW level can continue survive only if cogeneration.In order to improve the heating capacity of #1 unit of thermal power plant of Dalian development zone and meet the increasing heating demand,the exhaust heat of the steam turbine is recycled for heat supply.Heat transformation is carried out for #1 unit of thermal power plant of Dalian Development Zone,the main work is as follows:(1)The heat supply status and the existing problems of the thermal power plant of Dalian Development Zone are analyzed.The technical and economic feasibility of two heat supply schemes are analyzed contrastively.After the high-back-pressure scheme is determined,the operating parameters and energy consumption before and after transformation are analyzed.(2)In order to meet the demands of high-back-pressure operation of steam turbine after transformation,transformations are carried out for the low pressure cylinder.The thermodynamic characteristics of the two transformation schemes are analyzed contrastively,and the efficiency of the two schemes under different load and back pressure are also analyzed.And the structural strength and vibration characteristics of the last-stage blade are calculated and analyzed.(3)The corresponding transformations are carried out to the turbine of feed pump of #1 unit,condenser,condensate polishing unit,circulating pump of heat supply network and low-pressure bypass of #2 unit to adapt the changess of operation conditions after transformation.(4)The economic benefits under different heating load after transformation are analyzed.The results show that the larger the heating area is,the more the recoverable exhaust heat is,and the higher the economic benefit.