Research On The Optimal Set Value Of Oxygen Content In Power Plant Boiler

Thermal power is still the most important way in electric power generation, and it’s the backbone of the whole electric power industry. The efficiency and stability of the boiler’s combustion process means a lot to the economic benefits and the long term safety and stable operation of the whole plant. The flue gas oxygen content of the boiler can directly reflect the fuel’s combustion conditions in the boiler. Therefore, the research on the optimal set value of power plant boiler oxygen content is of great practical significance. The optimization of the power plant boiler oxygen content’s fixed value mainly includes two parts, modeling of the boiler tail flue gas oxygen content and the optimal value calculation of oxygen content’s fixed value.Through mechanism analysis, this paper puts forward a kind of mechanism method of flue gas oxygen content modeling. According to the different methods of oxygen content measurement, the model has two different forms, dry oxygen content form and wet oxygen content form. And dynamic compensation is added to the model to promote the measurement precision of the model. Using random sampling method, groups of operating data under different working conditions are collected from the actual history operating database of a certain power plant. On this basis, the flue gas oxygen content LS-SVM model is established. Althrough mechanism model has high accuracy, it’s dynamic characteristics is kind of poor. Due to excessively depending on the quality and comprehensiveness of the training data, LS-SVM model lacks of sustainability under certain conditions.Combining with the advantages and disadvantages of these two kinds of flue gas oxygen content modeling method, a composite model is established based on the combination of mechanism analysis and LS-SVM. This paper uses the composite model as the basis of oxygen content fixed value optimization, uses the highest boiler efficiency as the optimization goal, and uses the genetic algorithm as the optimize algorithm to calculate the optimal set value of flue gas oxygen content under both current operation conditions and varying load conditions. Plant operators can use the optimized calculating results as a guidance to ensure the power plant run with economy, safety and stability.