Abstract
The ultra supercritical boiler technology with double reheat can significantly increase the efficiency of a Rankine cycle power plant, and reduce fuel consumption for a given output. Recently China is developing 1000MW ultra supercritical boiler with double reheat which is arranged in tower type and the steam parameters are 350bar, 605℃/613℃/613℃. Thermal-hydraulic analysis is the key factors for the design and operation of ultra supercritical boiler with double reheat. According to the boiler structure and furnace-sided heat flux, the water wall of an ultra supercritical tower boiler with double reheat is treated in this paper as a flow network system consisting of series-parallel loops, pressure grids and connecting tubes. Based on the mass, momentum and energy conservations and some supplementary equations, a mathematical model is developed. Pressure drop, mass flux distribution, outlet vapor temperatures and metal temperatures data in the water wall at BMCR (boiler maximum continuous rating), 75% THA (turbine heat acceptance) and 30% THA load are obtained by iteratively solving the mathematical model. The results show that the water wall in the ultra supercritical boiler can operate safely.
