350 MW余热锅炉变工况运行特性分析

  目的  整体煤气化联合循环（IGCC）发电技术是高效、低碳的发电技术，余热锅炉是IGCC的组件之一。文章旨在研究余热锅炉变工况运行特性以提高整体煤气化联合循环发电技术的效率。  方法  通过分析余热锅炉的工作原理及传热传质原理，使用MATLAB软件展开编程计算，探究给水温度、给水压力、液相换热系数以及气相换热系数与余热锅炉内吸热量的关系。  结果  结果发现，当液相换热系数在200～1 000 W/(m2·K)和气相换热系数在20～100 W/(m2·K)范围内时，如果给水温度从30 ℃增加到100 ℃或给水压力增加，余热锅炉的吸热量将不断减少。反之，假设给水温度在30～100 ℃范围内，当液相换热系数从200 W/(m2·K)增加到1 000 W/(m2·K)或气相换热系数从20 W/(m2·K)增加到100 W/(m2·K)时，余热锅炉的吸热量不断增加。  结论  在液相换热系数与气相换热系数不变的情况下，给水温度或给水压力增加，余热锅炉的吸热量会减少；在给水温度与给水压力不变时，液相换热系数或气相换热系数增加，余热锅炉的吸热量会增加。

Analysis on Operation Characteristics of 350 MW Waste Heat Boiler Under Variable Working Conditions

  Introduction  Integrated Gasification Combined Cycle (IGCC) power generation technology is a high-efficiency and low-carbon power generation technology. A waste heat boiler is one of the components of IGCC. This paper aims to study the off-design operating characteristics of waste heat boilers and improve the efficiency of integrated coal gasification combined cycle power generation technology.   Method  The working principle and heat and mass transfer principle of the waste heat boiler were mainly analyzed by MATLAB software to carry out programming calculations to explore the relationship between feed water temperature, feed water pressure, liquid-phase heat transfer coefficient, gas-phase heat transfer coefficient and heat absorption in waste heat boiler.   Result  The results show that when the liquid-phase heat transfer coefficient is in the range of 200～1 000 W/(m2·K) and the gas-phase heat transfer coefficient is in the range of 20～100 W/(m2·K), as if the feed water temperature increases from 30 ℃ to 100 ℃ or the feed water pressure increases, the heat absorption of the waste heat boiler decreases continuously. In case the feed water temperature is in the range of 30～100 ℃, when the liquid phase heat transfer coefficient increases from 200 W/(m2·K) to 1 000 W/(m2·K) or the gas phase heat transfer coefficient increases from 20 W/(m2·K) to 100 W/(m2·K), the heat absorption of the waste heat boiler increases continuously.  Conclusion  Under the condition that liquid-phase heat transfer coefficient and gas-phase heat transfer coefficient remain unchanged, the feed water temperature or pressure increases, and the heat absorption capacity of the waste heat boiler will decrease; While the feed water temperature and pressure remain unchanged, the liquid-phase heat transfer coefficient or gas-phase heat transfer coefficient increases, and the heat absorption capacity of the waste heat boiler will increase.