Cross Compound Turbine Generator Unit With Elevated and Conventional Turbine Layouts

Abstract

This engineering study demonstrates the feasibility and advantages of a cross compound unit with an elevated and conventional turbine layout. Existing materials and equipment manufacturing capabilities were used to design a double reheat unit using the elevated and conventional turbine layout with other mature energy-saving systems to achieve a net efficiency of 48.92%. The development of conventional coal-fired power plants is reviewed to describe the existing bottlenecks in high-efficiency Super Critical (SC) and Ultra Super Critical (USC) electrical generation units. The development of 700 °C Advanced Ultra Super Critical (A-USC) units has been much slower than expected mainly due to the material limitations. Double reheat systems increase efficiency but also significantly increase cost and complexity. This design reduces the use of expensive high-temperature materials, with significantly lower piping costs as well as lower pressure drops and heat losses which increase the efficiency and the performance-price ratio.