Supercritical and ultrasupercritical coal-fired power generation

Abstract

Pulverized coal combustion (PC) is the most widely used technology in coal-fired power plants globally. The technology’s developments in the past decades have primarily involved increasing plant thermal efficiencies by raising the steam pressure and temperature. Based on the differences in temperature and pressure, the technology is categorized into three tiers: subcritical, supercritical (SC) and ultrasupercritical (USC).Coal consistently contributes to over 75% of electricity in China (China Bureau of Statistics 2009). To meet its ever growing demands for electricity, China has seen rapid growth of coal-fired power generation. From 2003 to 2009 the country more than doubled its coal-fired generation capacity, making its fleet the largest in the world. However, the fuel consumption per unit of electricity generated during this period has steadily decreased (Figure 3). The use of SC/USC technology has significantly contributed to the improvement of energy efficiency. In 2004 China surpassed the U.S. in average fleet efficiency (EIA 2009). As SC/USC continues to be the plant type of choice for coal burning in China, average fleet efficiency will continue to increase over time.