Model-free boiler combustion optical control method based on numerical optimization extremum searching

Abstract

The invention discloses a model-free boiler combustion optical control method based on numerical optimization extremum searching. The model-free boiler combustion optical control method based on numerical optimization extremum searching includes the steps that 1, the boiler efficiency eta (j) of a boiler combustion system and the nitric oxide emission value NOx (j) at all moments in a time window from the moment (k-n) to the moment k are collected, and an allowable error epsilon is set; 2, the average value eta of the boiler efficiency and the average value NOx of the nitric oxide emission value within the time window from the moment (k-n) to the moment k are worked out, and eta and NOx are used as the boiler efficiency and the nitric oxide emission value of the current moment k; 3, the boiler efficiency eta and the nitric oxide emission value Nox of the current moment k are subjected to normalization, and a single-goal function J(k) is worked out; 4, the change gradient gk of performance indexes along all layers of operation quantities; 5, the search direction dk is worked out; 6, the step length factor ak is worked out; 7, the operation quantity ui(k+1) to be optimized the next moment is worked out; and 8, the steps 2-7 are conducted repeatedly till algorithm convergence, and then the optimal operation quantity is obtained.

Description

technical field [0001] The invention belongs to the field of energy systems, and in particular relates to a model-free boiler combustion optimization control method based on numerical optimization extreme value search. Background technique [0002] With the emphasis on improving the quality of the atmospheric environment and protecting the ecological environment, the country's standards for pollutant discharge from power plant boilers are becoming more and more stringent. For example, my country's latest emission standards require that the NOx emission concentration of coal-fired power plants should be lower than 100mg / Nm 3 . [0003] At present, measures to control nitrogen oxides NOx emissions can be roughly divided into two categories. The first category is to reduce newly formed nitrogen oxides NOx during the combustion process, including various low-nitrogen combustion technologies, such as low-nitrogen burners, air staged combustion , fuel staged combustion, etc.; th...

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Problems solved by technology

For boilers using low-nitrogen combustion technology, when the load and coal quality are relatively stable, it is easy to obtain higher boiler efficiency and lower nitrogen oxide NOx emissions by changing the operating parameters through certain combustion adjustment methods; however, due to At present, thermal power units participate in peak regulation and frequency regulation, and their load changes frequently. Coupled with variable coal quality, it is easy to deviate from the design conditions of low-nitrogen combustion. It will cause problems such as coking in the furnace, high-temperature corrosion of the water wall in the burner area, and high carbon content in the ash. Therefore, it is difficult to achieve the desired effect by using conventional dynamic optimization control algorithms.

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