Study On The Low Nox Combustor Modification Of 600MW Boiler

As everyone knows,energy is the material base of the development and progress of the whole society.Considering the large proportion of coal reserves in our country,thermal power generation is still the main way of power supply in the next few decades.However,considering the damage to the atmospheric environment and even the whole ecosystem by coal-fired power plants,the government has gradually enforced power plants up to standards for ultra-low emissions.Therefore,the power industry has joined hands with scientific research institutes to continuously update and reform coal-fired technologies and equipment so as to achieve low nitrogen combustion in boilers.Based on the four corner tangentially fired 600 MW boiler in Shenhua power plant,the revamping scheme of low NOx burner is put forward.The central idea of the scheme is to achieve air staged combustion through the "double scale" arrangement,and to analyze whether the coal species are suitable for deep grade combustion and the use of dense burner.After putting forward the plan,the numerical simulation of the four corner tangentially fired pulverized coal boiler has been carried out by using Fluent software.The temperature of the furnace and outlet,the concentration of combustion components,the concentration of combustion products and the concentration of NOx are confirmed,and the indexes before and after the transformation are compared.The simulation results show the superiority of the modification scheme.The lateral wind increases the rigidity of the air jet,and the retaining wall is used to burn the pulverized coal in the central area,thus effectively protecting the water wall.The vertical air staged combustion effectively allocates the heat load and reduces the overall temperature of the furnace.The simulation results show that the NOx concentration of the furnace outlet is decreased from 300mg/m3 to 100mg/m3 before and after the retrofit.After confirming the reliability of the reconstruction plan,the construction has been carried out according to the scheme.After the modification project,the cold test and numerical simulation results are in good agreement,which confirms that the aerodynamic field meets the design requirements.By thermal combustion test,the combustible content of the fly ash at the outlet of the furnace is smaller,the temperature of the exhaust gas is reduced,and the actual thermal efficiency of the boiler is basically the same as before the reform.At the same time,the method of reducing the NOx emission of the outlet by changing the burner angle is put forward,which shows the advantages of upgrading and changing the burner.Through field operation test,the concentration of NOx after transformation,the value is about 100mg/m3,fully achieved the purpose of reform,in line with national environmental standards.After 9966 hours of operation,the furnace is stopped to check the coke in the water wall and the nozzle at the furnace,and it is found to meet the expected target.In summary,the transformation idea of this topic using "double scale" layout of the old boiler equipment,through simulation,the cold test confirmed that the construction and transformation method and adjusting the burner in operation,low nitrogen reached the purpose of the reform.This method is economical and feasible,and can provide a powerful basis for other units.