Study on Hydrodynamic Calculation of"Spiral-vertical"Water Wall of Supercritical Coal-fired Boiler
Supercritical boilers with large capacity and high parameters are the development trend in coal-fired power generation in China.Most mainstream supercritical boilers use spiral-vertical water walls,but hydrodynamic characteristics and flow distribution often causes operational problems.A typical spiral vertical water wall is modeled and calculated based on the hydrodynamic flow network system,combining mass and momentum conservation.According to the structure of the boiler water wall,the flow circuit is divided,pressure nodes are set,and the resist-ance coefficient and flow rate are calculated in sections.The larger the resistance coefficient in the spiral tube,the smaller the flow rate;The pipeline with the largest resistance coefficient in the vertical water wall(81~90 circuit)has the lowest flow rate.However,in view of a large flow rate in the back wall,the maximum flow rate is in the 71 circuit rather than in the 50~55 circuit with the minimum resistance.For water wall pipelines with the smallest flow rate,it is easy to cause overheating problems.A larger pipe diameter and small weld beading are impor-tant to ensure the safe operation of the boiler.
supercritical boilerhydrodynamic calculationspiral water cooled wallvertical water wall