燃煤电站锅炉运行参数对其热效率影响的试验研究

Research of the Effection of the Operating Parameters on the Coal-fired Utility Boiler's Thermal Efficiency

针对某电厂亚临界压力、一次中间再热、控制循环燃煤汽包锅炉,分析研究了省煤器出口氧量及燃烧器区域不同的二次风量分配对锅炉热效率的影响规律和程度,并着重分析比较了在省煤器出口氧量一定的前提下,二次风沿炉膛高度方向的分配方式对锅炉热效率的影响,得出了当二次风沿炉膛高度自下而上呈现“高位缩腰型”分布时,锅炉热效率较“倒塔形”或“方型”分布高。同时,二次风的“高位缩腰型”分布可使燃烧器区域的氧量分布沿炉膛高度方向呈现由高到低、再由低到高的变化,符合分级燃烧能够降低燃煤锅炉NOx排放的要求,研究结果对燃煤电站锅炉实现更加经济、环保运行有重要指导意义。

For a sub-bituminous coal-fired utility boiler with sub critical forced circulation and one grade re heaters of a 300 MWe unit, the influence law and extent of operating parameters, such as oxygen content of the flue gas at the exit of economics, and the secondary air distributions along the height of furnace, to the coal fired utility boiler＇s thermal efficiency were given. In the same oxygen content of flue gas at the exit of economics, the thin waist distribution of secondary air with the high position is the best comparing with other two distributions, uniform and back tower, from the point of thermal efficiency. The research result is meaningful for guiding the utility boiler to operate with the aim of higher thermal efficiency and low flue gas emissions.