(400c) Evaluation of 2MWe Oxy Circulating Fluidized Bed Boiler Performance

Many countries are investing extensively in research efforts to develop eco-friendly energy conversion technologies, due to the stringent environmental regulations and continuously increasing energy consumption with population growth. Among the clean technologies, CFB(Circulating fluidized bed) boiler, which is classified as a promising technology, has been investigated because of various fuel availability, distribution of uniform temperature and higher energy efficiency. In addition to CFB boier, there are other wayst to achieve eco-friendly energy conversion, such as oxy combustion, which is proposed to substitute air by oxygen in boilers to avoid dilution of the fuel gases with nitrogen in order to facilitate CO₂ handling for deposition, and the upgrading of steam quality which may help to increase electric conversion efficiency and to reduce CO₂ emission. Therefore, oxy-fuel circulating fluidized bed boiler with super-critical steam cycle has been developing in the world. In this study, the performance of 2MWe oxy-CFB boiler with super-critical steam cycle is evaluated using 1.5 dimensional model which had been based on IEA-CFBC model. Also, experimental results from an air-fired CFB boiler which has been operated in Korea Institute of Energy Research are used to confirm performance results from 1.5 dimensional model. The effect of oxygen concentration in the input to the oxy-CFB boiler on solid hold-up, temperature, pressure and heat flux in a riser has been determined.