97/04034 Coal-fired advanced gas turbine systems for repowering

Abstract

Under sponsorship of the DOE Pittsburgh Energy Technology Center, a team led by United Technologies Research Center has been investigating High Performance Power Systems (HIPPS). The prime objective of these investigations has been greenfield designs of highly efficient (47% HHV) coal-fired power plants using High Temperature Advanced Furnaces (HITAF) to preheat combustion air for gas turbines. Much of the efficiency advantage of the HITAF approach can be realized in the repowering of older steam plants. The following paper describes the preliminary investigations of repowering coal-fired stations using the next generation aero-derivative gas turbine in combined cycle and Humid Air Turbine (HAT) configurations. An 100 MW + industrialized version of the Pratt and Whitney 4000 aero engine is the basis of intercooled gas turbine cycles which use both coal and natural gas to heat the gas turbine combustion air. How the heat from the intercooler and the turbine exhaust is used in repowering depends on the desired steam conditions and power level. Steam station sizes from 90 to 200 MW with steam conditions ranging from 1,250 psi/950 F non-reheat to 2,400 psi/1,050 F/1,050 F reheat were investigated. Efficiencies in the 42--47% range (HHV) are projected. The cost of electricity is applicationmore » specific, but should be significantly less than the original station at emission levels which are one-quarter or less than current New Source Performance Standards.« less