Low NOx Transformation Affect The Performance Of600MW Boiler

Pulverized coal combustion is the main source of energy of the thermal power in our country,however, the pulverized coal combustion will release nitrogen oxide as one of atmospheric pollutants. The global researchers have researched a lot on the technology of coal-fired boiler NOx control, and study out of the method in a variety of applicable to engineering. A variety of methods to reduce NOx emissions emissions will also bring a certain impact on boiler performance,This article uses performance computing and numerical simulation to study on the changes of a600MW boiler low NOx transformation.Domestic colleges and universities are mostly used the former Soviet union73thermal calculation standard for the pulverized coal fired boiler performance calculation. This standard promulgated in the period which the boiler capacity is small,and it can make mistakes if the modern large-scale units have been still using this method. The article firstly analyzes the changes on the new joined formula,calculation method and how to choose some parameters between the new98standard and old73standard, and this article focuses on the different parameters influence on boiler smoke exhaust temperature. Comparison of the results of the field measured values and the results of the two standard versions,then select a more suitable approach on this basis. Analysis of changes in boiler performance before and after the transformation of low-NOx, eventually come around the furnace section of the transformation of the heat load, the furnace exit gas temperature, exhaust temperature and other parameters as a basis for reformThis artical uses Fluent the numerical simulation software for simulating the whole boiler combustion process. The first step is using Gambit drew the hedge boiler structure grid, then the cold and hot start of boiler, simulation operation until the residual convergence. It can obtain boiler outlet flue gas temperature, velocity distribution, etc, before and after the reconstruction by the numerical simulation and it verifies each other combining with the boiler performance and settlement results. It can finally instruction that after the boiler air staging transformation, the outlet smoke temperature will rise slightly and the change of theboiler efficiency is small and the NOx emissions will significantly reduced.