This study aims to present various design aspects and realizable performance of the natural gas fired semi-closed oxy-fuel combustion combined cycle (SCOC-CC). The design parameters of the cycle are set up on the basis of the component technologies of today's state-ofthe-art gas turbines with a turbine inlet temperature between 1400°C and 1600°C. The most important part of the cycle analysis is the turbine cooling, which considerably affects the cycle performance. A thermodyruxmic cooling model is introduced in order to predict the reasonable amount of turbine coolant needed to maintain the turbine blade temperature of the SCOC-CC at the levels of those of conventional gas turbines. The optimal pressure ratio ranges of the SCOC-CC for tn'o different turbitie iniet temperature levels are researched. The performance penalty due to the CO2 capture is examined. The influences of the purity of the oxygen provided by the air separation unit on the cycle peiformance are also investigated. A comparison with the conventional combined cycle, adopting a postcombustion CO2 capture, is carried out, taking into account the relationship between the petformance and the CO2 capture rate.
Journal of Engineering for Gas Turbines and PowerCopyright ©2012 by ASME NOVEMBER2012, Vol. 134 / 111702-1 that of the conventional combined cycle adopting a postcombustion CO2 capture from the perspective of the relationship between the performance and the capture rate.