Medium temperature carbon dioxide gas turbine reactor

A carbon dioxide (CO2) gas turbine reactor with a partial pre-cooling cycle attains comparable cycle efficiencies of 45.8% at medium temperature of 650degreesC and pressure of 7 MPa with a typical helium (He) gas turbine reactor of GT-MHR (47.7%) at high temperature of 850degreesC. This higher efficiency is ascribed to: reduced compression work around the critical point Of CO2; and consideration of variation in CO2 specific heat at constant pressure, C, with pressure and temperature into cycle configuration. Lowering temperature to 650degreesC provides flexibility in choosing materials and eases maintenance through the lower diffusion leak rate of fission products from coated particle fuel by about two orders of magnitude. At medium temperature of 650degreesC, less expensive corrosion resistant materials such as type 316 stainless steel are applicable and their performance in CO2 have been proven during extensive operation in AGRs. In the previous study, the CO2 cycle gas turbomachinery weight was estimated to be about one-fifth compared with He cycles. The proposed medium temperature CO2 gas turbine reactor is expected to be an alternative solution to current high-temperature He gas turbine reactors. (C) 2004 Elsevier B.V. All rights reserved.