석탄 등급에 따른 석탄 화력-초임계 CO₂ Brayton 발전 사이클의 성능 비교

Researches and efforts to improve the efficiency of coal-fired power plants have been in progress consistently. Based on the conventional steam Rankine cycle applied to the coal-fired power plants, developments for more efficient power cycles such as supercritical steam (SC) and ultra-supercritical steam (USC) cycles have been actively performed. Among the various technologies to improve the efficiency of coal-fired power plants, the supercritical CO₂ Brayton cycle has been regarded as a promising candidate for the conventional steam Rankine cycle. In this research, process design and modeling of coal-fired power plants with both circulating fluidized bed combustion (CFBC) boiler and supercritical CO₂ Brayton cycle were conducted under ASPEN Plus environments. In order to quantitatively compare the results derived from the low rank coal (CASE 1) and high rank coal (CASE 2), total electric power consumptions and gross powers were investigated closely, and the system net efficiency was also calculated with total auxiliaries as a parasitic load. The net efficiency of the CASE 1 using a high rank coal is 4.84% higher than for the CASE 2 with a low rank coal.