Design Of Combustion Control System For Gas-fired Boiler

With the continuous improvement of crude steel production in China's iron and steel enterprises,secondary energy resources(such as blast furnace gas,converter gas)are continuously produced in the process of smelting steel.Utilizing the remaining blast furnace and coKe oven gas to generate electricity is the only way for iron and steel enterprises to save energy and reduce emissions.From the point of view of 130 t/h medium temperature and pressure boilers in Baotou Steel Power Supply Plant,the operation of two gas-fired boilers can consume 240,000 cubic meters of blast furnace gas per hour.Gas-fired boilers need a lot of gas and water in the combustion process.Therefore,in order to ensure the safe,stable and economic operation of boilers,improve the combustion efficiency of boilers,reduce gas consumption,the combustion control system of gas-fired boilers is optimized.Be imperative.Realizing automatic regulation of blast furnace is the most important part of combustion control of gas-fired boilers and the main means to realize steady operation of equipment,reduce safety risKs and accidents.Therefore,it is urgent to design a stable,safe and efficient automatic control system.In this paper,the production and operation principle of gas-fired boilers are explained in detail.At the same time,the energy transformation of gas in the combustion process of boilers is analyzed.Finally,the factors affecting the combustion of gas-fired boilers,such as combustion efficiency,fuel quantity,oxygen and dynamic change of negative pressure,are analyzed and explained in detail.Firstly,on the principle of understanding the production process and process configuration of 130t/h gas-fired boiler in Baotou Steel Power Supply Plant,this paper mainly analyses the design idea,system structure and worKing principle of DCS control system of the boiler,and studies the water level control system of the boiler drum,superheated steam control system and combustion control system.Secondly,the main circuit and control circuit of gas-fired boiler are simply analyzed.According to the requirement of computer monitoring in production site,the monitoring system of gas-fired boiler is simulated by computer configuration software.The monitoring system can monitor the production process in real time,guide the operation in production site and alarm the abnormal high temperature.At the same time,the paper maKes a brief analysis of the thermal efficiency and air-fuel ratio of gas-fired boilers,and expounds the factors affecting the thermal efficiency of boilers from the aspects of heat loss of exhaust gas.Finally,the optimization of boiler combustion control system is mainly studied in this paper.Through the analysis of double cross limiting control system and the use of high and low value selector and bias unit,the combustion control problem of gas-fired boiler is basically solved.At the end of the paper,the stochastic disturbance is used to simulate the combustion control system of gas-fired boiler,and the simulation results have achieved the expected results.