IJSRP, Volume 2, Issue 9, September 2012 Edition [ISSN 2250-3153]
P.Srinivasarao, Dr. P. Ravinder Reddy, Dr.K.Vijaya Kumar Reddy
Considering the high capital cost involved in new generation “clean technologies” developing countries like India having an abundance of cheap fossil fuel reserves have to give a major thrust to improvement in fossil-fired power technologies. Steam turbine based generating plants form the backbone of power generation in many countries in our country too, Base load is presently largely generated by fossil fuel based power plants. Most of these plants employ sub-critical coal fired boilers driving steam turbines to generate power. The adoption of “Supercritical cycles” for thermal plants on a wide scale has the ability to improve overall system efficiency, as well as provide benefits of lower emissions both on land & in air. Steam cycles for supercritical application operate at very high pressure & temperatures; these are thus characterized by features that take full advantage of the advanced parameters like higher expansion in turbines, more stages of feed heating & higher input levels to boilers, contributing to higher system efficiency. All the components of the cycle are optimally designed to take advantages of these elevated parameters. Additionally, these cycles are built considering large size machines to take full advantage of economies of scale, thus reducing “Footprint” per MW generated. All of these contribute to lower land & water use, less consumption of coal & reduced wastes & emissions. The paper deals with the design of these cycles in detail in addition to comparing them to the existing sub critical cycles, highlighting areas of improvement.