The Cause And Improvement Of High Exhaust Gas Temperature In Power Plant

At present, energy saving and emission reduction of thermal power units is an important national policy. The high exhaust gas temperature becomes a difficult problem to the economic operation of the coal-fired power plants. The high exhaust gas temperature can decrease the efficiency of boiler and add the net coal consumption rate. Lowering exhaust gas temperature is of great importance for energy saving.In this article, based on a lot of literatures, the reasons of high exhaust gas temperature mainly include:the increasing of air leakage to furnace and mixed cold air, fouling of the boiler heating surface, ash deposition of heat transfer components and the leakage ratio of air pre-heater, unreasonable design of heating surface layout, changes of coal category. According to the reasons, so the measures of lowering the exhaust gas temperature mainly include:eliminating the air leakage of the boiler, keeping heating surface clean, optimization design of the back-end surface, installing low pressure economizer and optimized operation of the unit.At this article, the cause of high exhaust gas temperature was analyzed and the improving measures were put forward. This article introduced the conditions of the high exhaust gas temperature of the NO.5boiler of a power plant in China Datang Corporation and analyzed the factor of the high exhaust gas temperature combined with actual operation data. In order to decrease the exhaust gas temperature, the execute solution of installing low pressure economizer was put forward, the feasibility and the economic benefit of the solution was demonstrated.