Operation Optimization And Superheater Tube Explosion Analysis Of A 600 Mw Sub-critical Boiler

The optimization and adjustment of boiler combustion can effectively improve boiler efficiency and reduce NOx emission, which has of practical significance.The 600 MW sub-critical boiler was studied in this article. An experimental research of boiler combustion optimization was carried out for the problems of low efficiency, high reheated steam temperature and flue gas temperature deviation, in which the influence of oxygen concentration, air distribution mode, over fired air ratio and mill combinations was analyzed. The research results indicate the boiler efficiency is highest when the oxygen concentration of air preheater inlet is 2.0%. The temperature deviation of flue gas for each side is least, when the OFA damper is full open. The boiler efficiency is higher when the lower mills are running.The superheater pipe rupture occured, while the boiler was normal operating. According to the test analysis, the installation of burst superheater pipes is reasonable. The temperature deviation of two sides exists in the flue gas duct, but the pipe temperature overheat less, and the highest temperature is lower than the maximum temperature that pipe can endure. Through detection, the burst pipes have thicker oxidation skin, and emerge balling phenomenon, so the pipe aging is the main reason which leads to pipe explosion.