为获得超超临界压力下CFB锅炉水冷壁内、外传热特性，建立了水冷壁总传热系数计算模型，并通过高温高压条件下的实验数据拟合得到了工质侧传热系数关联式，将此关联式代入水冷壁总传热系数计算模型，使其预测精度大为提高。研究结果表明：水冷壁传热性能是工质侧传热系数、烟气侧传热系数以及水冷壁管导热性能耦合作用的结果；工质侧传热系数沿着炉膛高度的增加而增加，在30 m时出现第一次峰值，后墙、中隔墙和侧墙水冷壁传热系数分别为24.7，25.9和27.3 kW/（m2•K），而且在此区间内波动剧烈，并在52 m附近达到最大值，后墙、中隔墙和侧墙水冷壁传热系数分别为33.8，35.1和36.2 kW/(m2•K），超过50 m以上区域则迅速下降；在100% BMCR负荷下，水冷壁总传热系数沿着炉膛高度方向减小，在30 m以下区域，中隔墙、后墙、侧墙水冷壁总传热系数分别从220，215.2和213 W/（m2•K）下降到了178，174和170 W/(m2•K)，而在30 m~50 m区间仅下降了4~5 W/（m2•K），在炉膛顶部区域总传热系数几乎不变。

In order to obtain the internal and external heat transfer characteristics of the CFB boiler watercooled wall under ultrasupercritical pressure,a calculation model for the total heat transfer coefficient of the watercooled wall was established,and through the experimental data under high temperature and high pressure conditions,the correlation of the heat transfer coefficient on the working fluid side is obtained.This correlation is substituted into the calculation model of the total heat transfer coefficient of the water wall,which greatly improves the prediction accuracy.The research results show that the heat transfer performance of the water wall is the result of the coupling of the heat transfer coefficient on the working side,the heat transfer coefficient on the flue gas side,and the thermal conductivity of the water wall; The heat transfer coefficient on the working side increases along with the increase of the furnace height,and the first peak appears at 30 m and fluctuates violently.The heat transfer coefficients of the water walls of the rear wall,middle partition wall and side wall are 24.7,25.9 and 27.3 kW/(m2•K）.The maximum value is reached near 52 m,where the heat transfer coefficients of the back wall,middle partition wall and side wall are 33.8,35.1 and 36.2 kW/(m2•K）.For the area over 50 m,they will drop rapidly.At 100% BMCR load,the total heat transfer coefficient decreases along the height of the furnace.In the area below 30 m,the total heat transfer coefficients of the back wall,side walls,and partition walls have decreased from 220,215.2 and 213 W/(m2•K) to 178,174 and 170 W/(m2•K）.But in the range of 30 m~50 m,it only falls by 4~5 W/(m2•K）,with the total heat transfer coefficient in the top area of the furnace almost unchanged.

TK223.3

国家自然科学基金(52076172)