Studies on Carbon Dioxide Cycles for Power Generation : 2nd Report, Discussion on Several Proposed Cycles

Abstract

This paper presents the performance characteristics of gas turbine cycles with supercritical back-pressure and several condensation cycles, using carbon dioxide as a working fluid. They are computed from the data on the thermodynamic properties of CO2. As a result, it is shown that thermal efficiency in CO2 cycles increases at the rate of ( 3 4 ) % in proportion to a turbine inlet temperature rise of 100 °C and is little affected by turbine inlet temperature rise of 100°C and is little affected by turbine inlet pressure higher than 200 ata. Also, thermal efficiency of CO2 gas turbine cycle with supercritical back-pressure is lower by ( 6 9 ) % than that of CO2 condensation cycles. Some CO2 condensation cycles exhibit a better performance than the conventional steam power-plant cycles at a turbine inlet pressure of about 250 ata and turbine inlet temperatures higher than 600 °C.