A High Efficiency Coal-Fired Power Technology With Elevated and Conventional Turbine Layout

The bottlenecks which in developing high-efficiency Ultra Super Critical (USC) coal power technology is analyzed under the background of great pressure of reducing CO2 emission on coal power industry. The development of 700°C Advanced Ultra Super Critical (A-USC) technology has been much slower than expected mainly due to the material limitations. Double reheat systems increase the efficiency at the cost of significant increases in expense and complexity. A cross compound unit with an elevated and conventional turbine layout greatly shorten the expensive high-temperature piping, significantly cutting the piping costs as well as reduce pressure drops and heat losses which increase the efficiency and the performance-price ratio of the power unit. Engineering study demonstrates the feasibility and advantages of this design. Existing 600 °C materials and equipment manufacturing capabilities were applied to the double reheat unit with the elevated and conventional turbine-generator layout, and adding other mature energy-saving technologies which had succeed in Shanghai Waigaoqiao No.3 Power plant to achieve a net efficiency of 49.8% (6849Btu/kWh, Lower Heating Value (LHV)). Combined with a series of innovative technologies that can improve the operating efficiency and keep the efficiency from decreasing, the annual net efficiency can achieve 48.8% (LHV). This efficiency level is high enough to meet the strict CO2 emission standard (636g/kWh) issued by Environmental Protection Agency (EPA) of the USA, showing significant demonstration of reducing CO2 emission.