Advanced Natural Circulation Model in Evaporation Circuits of Thermosiphon Waste Heat Boilers

Although existing models of natural circulation in steam boilers involve numerous simplifications, the physical processes that occur in real-time are not considered. This study sought to improve the natural circulation model in the evaporation circuit of a thermosiphon waste heat boiler using an analytical solution and numerical simulation results. A modified natural circulation model was developed using ranked variables of velocity and heat flux in the evaporator ring channels. These results were obtained in the range of heat flux densities 1.074–9.973 kW/m2 and temperatures of the thermosiphons hot zone 477.4–487.1 K which is typical for a waste heat boiler for cogeneration power plant with gas turbine engine 6700 kW power.