Study On Optimization Of Deep Peak Regulation And Denitrification System For A 330MW Unit

Under the dual background of large-scale development of renewable energy and supply-side structural reform,thermal power units are facing deep adjustment of industrial roles,and it is the general trend to carry out flexible transformation of thermal power units.In order to promote the energy consumption revolution and promote the rapid upgrading and transformation of China’s energy supply side,the National Energy Administration has put forward clear requirements for the flexibility transformation of thermal power units.The optimization of the denitration system of thermal power units is an important part of the flexibility transformation.The optimal technical route for different units still needs to be further explored.Based on the actual transformation requirements of thermal power units,this paper proposes to continue the design of the scheme based on the design scheme,simulation verification,project implementation and analysis of the follow-up problems.It is of great practical significance for the flexibility transformation of thermal power units to obtain a feasible new scheme through simulation.The main contents of this paper are as follows:The research object of this paper is a 330 MW subcritical thermal power unit in Hebei Province.Through the test,the corresponding parameters and modeling data of the boiler under low load are obtained,and the simulation software Flownex is used to simulate and study it.The high temperature flue gas bypass is selected as the transformation scheme,and the data processing and analysis before the transformation are carried out.The scheme is simulated and calculated to guide the on-site implementation,and the on-site operation effect after the transformation is collected.According to the field data,the increase of flue gas temperature at the denitration inlet did not reach the expectation.Through the analysis of the results of the transformation scheme,it is found that the bypass flue gas volume does not reach the design value,the low calorific value of the burning coal and the insufficient adjustment of the field equipment are the main reasons affecting the transformation effect.Combined with the initial transformation experience and the analysis of the causes of the results,the further transformation of the research object is proposed.Based on the initial transformation scheme,the future transformation of the unit is designed.Firstly,the multiple schemes of the future transformation of the unit denitrification system are modeled,calculated,analyzed and demonstrated,and the transformation effect is predicted.On the basis of various mature schemes of feed water side temperature rise,a scheme of feed water temperature rise by steam extraction of low temperature superheater is proposed.Through theoretical calculation and simulation,the feasibility of the water supply heating scheme is verified,and the economy of the scheme is analyzed.Comparing the scheme with different technical schemes,the scheme has the advantages of good expected effect,small amount of renovation work,reasonable investment and small space occupation.Finally,this plan was developed as a follow-up transformation plan for the plant.It provides new ideas and solutions for the optimization and flexibility transformation of the denitration system of subcritical units,which has certain practical significance.