Abstract:
In order to reduce the pollutant emissions of a circulating fluidized bed boiler in a certain power plant and improve the economy of the boiler combustion operation, this article adopts the data-driven technology to achieve the multi-target combustion optimization for circulating fluidized bed boilers. Improved particle swarm optimization-based long short-term memory neural networks is used to establish the boiler’s mathematic model with NO
x emission, SO
2 emission and exhaust gas temperature as outputs, respectively. The relative error is regarded as a predictive evaluation index to determine the optimal network parameters. Secondly, the NO
x emission prediction model, the SO
2 emission prediction model and exhaust gas temperature prediction model are constructed based on improved particle swarm optimization-based long short-term memory neural network, long short-term memory neural network(LSTM),generalized regression neural network(GRNN), and a backpropagation neural network(BPNN). By comparing the evaluation indicators, the effectiveness of the predictive models constructed was testified in this paper; Finally, based on the non-dominated sorting genetic algorithm(NSGA-II), the combustion optimization adjustment schemes for CFBB under different operating conditions are obtained so as to reduce NO
x/SO
2 emission and maintain the stability of exhaust gas temperature at the same time. The results showed that compared with before optimization, the average NO
x emission was decreased by 10.583%, the average SO
2 emission was reduced by 25.812%, and the maximum reduction of SO
2 emission was 650 mg/m~3. In addition, the average exhaust gas temperature was decreased by 0.143%.