Study On Coupling Characteristics Of Efficiency And No_x Generation Of A 2030t/h Opposed Swirling Fired Boiler

The burnout air volume and excess air coefficient are important regulating parameters in the operation of coal-fired power generation boilers,which have important effects on the efficiency of boilers and the characteristics of NO_x generation.It is of great theoretical and practical significance to study the burnout air volume and excess air coefficient when the boiler efficiency and NO_x generation are synthetically optimal for improving the economy and environmental protection of boilers.In this paper,a 2030t/h opposed swirling coal-fired boiler was taken as the research object,and the quantitative evaluation index of the coupling between boiler efficiency and NO_x generation was established.Based on the evaluation index,the performance tests of variable burnout air volume and variable excess air coefficient under 100%,75%and 50%loads were designed and carried out,and the variation law of boiler performance was obtained.For the test process of burnout air volume regulation,the effects of burnout air volume on boiler efficiency and NO_x generation were studied respectively.The results show that the boiler efficiency decreases with the increase of burnout air volume under various load conditions.The NO_x generation at 100%and 75%loads decreases first and then increases with the increase of burnout air volume,and the NO_x generation at 50%load decreases with the increase of burnout air volume.The coupling quantitative evaluation index was used to compare the working conditions under different loads,and the comprehensive increase cost of each load was found to increase with the increase of burnout air volume.For the test process of excess air coefficient regulation,the effects of excess air coefficient on boiler efficiency and NO_x generation were studied respectively.The results show that the boiler efficiency increases first and then decreases with the increase of excess air coefficient under various load conditions.The NO_x generation increases with the increase of excess air coefficient.Using the coupling quantitative evaluation index established above,the comprehensive increase cost of each load under different working conditions were compared.It was found that the comprehensive increase cost of each load decreases first and then increases with the increase of excess air coefficient.Through further analysis of performance test and coupling evaluation index,the optimum burnout air valve opening and optimum excess air coefficient of the boiler at100%,75%and 50%loads under the current test conditions and coal type were obtained,which provides reference for the comprehensive optimization operation of the boiler.