Study of Water Wall Flow Distribution and Mass Outlet Temperature Distribution in Ultra-Supercritical Boiler Based on Pot-Furnace Coupling

ObjectivesWater wall over-temperature tube burst under deep peaking is one of the key problems facing the safe operation of boilers. A coupled boiler-furnace simulation method is proposed.MethodsThe heat flow distribution on the water wall surface under each operating condition is obtained by numerical simulation of combustion. Then, a calculation model of the mass side is established on the basis of Modelica, so as to study the distribution of water wall flow rate and the temperature distribution of the mass outlet of a 660 MW ultra-supercritical boiler.ResultsThe errors of key parameters of water wall outlet mass are all within 3%, which verifies the reliability of the model. The spiral water wall flow distribution shows negative flow characteristics at high loads and positive flow characteristics at ultra-low loads. Vertical water wall always shows negative flow characteristics, and the maximum temperature difference of the vertical water wall outlet mass is 37.60 ℃ at 100% turbine heat acceptance (THA), and increases to 138.33 ℃ and 141.27 ℃ at 40% THA and 30% THA, respectively. The (ultra) low load vertical water wall outlet mass temperature of the front and rear walls is high and the temperature difference is large, while the outlet mass temperature of the left and right side walls is low and the temperature difference is small.ConclusionsThe research results can provide a reference for the safe operation of the boiler under deep peaking.