Modern Coal-Fired Power Units for Ultra-Supercritical Steam Conditions (Review)

The share of coal generation in the global electricity production remains stable and prevails over other primary energy sources. A decrease in the coal-fired power generation in some EU countries and the United States is balanced by its stable growth in Asia (China, India, Indonesia, South Korea) and Africa (South Africa). In 2021, global coal generation increased by 9% to a new all-time high of 10 337 TW h. According to the forecast of the International Energy Agency (IEA), coal consumption in the power industry will remain at about the same level in the coming years, mainly due to the countries of Southeast Asia. Furthermore, at the UN climate conference held in Glasgow in November 2021, the official phasedown of all coal-fired generation was not set forth. Globally, 247.7 GW of ultra-supercritical (USC) power units, which are characterized by high efficiency and minimal environmental impact, have been commissioned during the past decade. Steam conditions of 32.58 MPa/610/630/623°C (for live, reheat, and, secondary reheat steam, respectively) and an efficiency of 48.92% were reached in a 1350-MW power unit at the Shenergy Pingshan II thermal power plant (TPP) (China). A review of the USC technology evolution in the world and basic solutions for boilers, flue gas treatment system, and steam turbines are presented. In Russia there are no plans to construct large coal-fired power units in the coming years. Development of a gas-and-oil fired power unit for ultrasupercritical steam conditions with elaborating the thermal cycle key equipment components—primarily the turbine and steam lines—can serve as a pilot project for mastering the USC technology.