The thermal load distribution of water wall is the key parameter for the structural design of water walls in supercritical and ultra-supercritical circulating fluidized bed boiler (CFB). In this paper, the temperature distribution of the water wall of a 350MW supercritical CFB boiler under typical working conditions was measured by installing 118 temperature measuring points at the back-fire water wall tube and adjacent fins. The deviation in the heat load of water wall as a function of furnace height, width and depth was obtained as well. The experimental results show that temperature of the working medium in water-wall tube increases with increasing furnace height. The thermal deviation of the steam temperature in water wall tube in the direction of furnace width and depth is large at the initial boiler start-up period, the transition period from dry to wet state, and the low load condition. Despite these, the heat load distribution of water wall at the same furnace height remains the same. The results provide a reference for the structural design and operation optimization of supercritical and ultra-supercritical CFB boiler.

The research work, Ascertaining the connection type between evaporating tube bundle and a steam drum shell on a Natural Circulation marine supercharged boiler, is important. For this reason the method, calculating the low-cyle fatigue life of supercharged boiler steam drums put forward by Xin-wei Zheng, et al., was put to use; Based on the relevant basic data from design department and two typical running conditions of one supercharged boiler, the cumulative fatigue damage ratio of welding technique was calculated. The calculated result proves that it exceeds the maximum value of 1.0 and the upper limit value of 0.75 in fossil-fuel power plants, respectively. So welding technique can’t guarantee the low-cycle fatigue life of this steam drum, the only connection type is expanded joint, and the connection type has been put into practice.