为获得直流锅炉实际蓄热系数，分析锅炉在亚临界或超临界状态下的不同运行特性，根据工质相变对水冷壁进行汽水分段，针对锅炉的各汽水流程部件计算汽水蓄热系数和金属蓄热系数，结合汽轮机调门开度及热耗率变化影响，提出了实际蓄热系数计算方法。以某660 MW超临界机组为例进行计算，结果表明：金属蓄热系数大于汽水蓄热系数，随着负荷升高，汽水蓄热系数变化不大，金属蓄热系数减小；考虑到汽轮机热耗率变化的影响，不同负荷下实际蓄热系数之间偏差有所缩小。

In order to obtain the actual heat storage coefficient of oncethrough boilers,the operating characteristics of the boiler in the subcritical or supercritical conditions are analyzed.The evaporating surface of the water wall is divided based on the phase change of the working media,and the steam-water heat storage coefficient and metallic heat storage coefficient of different components in the boiler steam-water circuit are calculated.Taking account of the steam turbine governing valve opening and heat rate change,a calculation method of the actual heat storage coefficient is put forward.Data from a 660 MW set are used to verify the proposed method.The results show the metallic heat storage coefficient is larger than the steam-water heat storage coefficient.With the increase of the load,the steam-water heat storage coefficient is barely changed but the metallic heat storage coefficient is reduced.Considering the impact of changes in heat rate of the steam turbine,the gaps between the actual heat storage coefficients under different loads has been reduced.

TK222

国家自然科学基金（51505483）；国家自然科学基金民航联合研究基金（U1833106）；天津市自然科学基金（15JCQNJC42900）；中央高校基本科研业务费（3122013C012）