Research On The Retrofit Of Air Preheater Sealing Device For 600MW Unit In A Coal-fired Power Plant

At present,the electric power energy in our country mostly comes from the coal-fired power plant.As more and more power plants was set up,the pollutions caused by the plant is raising.So,in order to protect the environment,energy conservation and emissions reduction is needed.In coal-fired power plant,the operation of the boiler efficiency has important effect to improve the efficiency of power generation.The air preheater is an important auxiliary equipment in thermal power plant,play a important role in reducing exhaust temperature and i ncreasing the first and secondary air temperature.Heat transfer performance directly affects the efficiency of the boiler,also plays a vital role in the safe and stable operation of power station.In this paper,we do some research about the air preheater in a coal-fired power plant.The power generation affecting the thermal efficiency and air preheater sealing modification method was studied,aimed to select the appropriate transformation method,improve the heat transfer performance of air preheater and boiler efficiency,at the same time,reduce the power consumption of the fan and induced draft fan,and guarantee the safe and stable operation of the specific system of power plant operation.In this paper,first of all,doing some research about the status and the principle of the air preheater,doing some analysis of the types and working principle of air preheater The air preheater of this power plant is the rotary air preheater,through to the running status of boiler air preheater is analyzed,various retrofit scheme was proposed,based on the comparison of many sided.It is concluded that the flexible contact seal renovation is more suitable for the actual situation of the power plant.Then the heat storage element was transformed.Through the systematic optimization of air preheater,the unit transformation was completed,and then analyze the actual operation data of the unit and air preheater air leakage of air preheater and the resistance test.Flexible contact sealing is adopted to the boiler,and two boiler air preheater leakage rate has a large amplitude reduced.The boiler air preheater leakage rate was reduced by 4% on average,air pre-heater flue gas side pressure drop were significantly.At the same time due to the lower air preheater leakage rate,reduces the boiler flue gas heat loss,the calculation based on the measured data shows that the transference can save electric about 2782320 kW.h,can save standard coal about 4335.24 tons,helpful to the economic and efficient running of the power plant.