Experimental Study And Application Of Layered Combustion Based On On-line Optimization

The capacity of thermal power units increase rapidly in our country in recent years, which cause the shortage of coal. And the gaseous pollutant made by coal combustion such as NOx and SO2create the serious environment problem. A serial macro-regulatory policies are issued by the government such as:increasing pollutant discharge fees to control the blindfold production expansion; applying the desulfurization electric power price to lead the clean production; carrying out energy-saving and environmental protection management to urge the research of advanced energy-saving and environmental protection technology. In this background the combustion optimization research is carried out in this article, including continuous gas emission monitoring, on-line combustion optimization and coal fine layered combustion.The continuous gas emission monitoring is the important method to realize boiler combustion real-time parameters and pollutant discharging concentration. Because of the characteristic of gas such as high temperature, high fine concentration, strong causticity and distributing unevenness, some advanced technologies are applied on gas sample collection and pretreatment equipment. The gas concentration such as CO, NOÏ„, O2and SO2are monitored by using spectrum analysis principle. The contrast testing results show that the continuous monitoring technology have high accuracy and reliability and can applied for on-line combustion optimization.In this article boiler efficiency and NOx discharging concentration models are built based on Support Vector Machine to offer the mathematical tool for on-line combustion optimization. According to boiler structure the combustion characteristic, an on-line high-temperature erosion model is built to predict the velocity of erosion and monitor the security of furnace heating surface quantificationally. The combustion optimization model composed by the above three models is combined with gas continuous monitoring technology to form the on-line combustion optimization, which have high precision accuracy and good engineering application and can vary well with the coal quality and unit load.The layered combustion technology is a simple and flexible coal arrangement technology which is always carried out by. practice because theoretic support and monitoring method are absent. In this article the computer fluid dynamics software Ansys is used to analyse the typical combustion condition of boiler to obtain the combustion characteristic in different layered mode quantificationally. With the instruction of computed results, layered combustion experimental research is carried out applied with on-line combustion optimization system. The optimized combustion style is obtained through evaluating the influence of combustion, clinker, soot, NOx emission and boiler efficiency in different layered style, which can widen the coal adptability, reduce the fuel cost, increase boiler efficiency and decrease NOx emission concentration.