CO2 based power cycle with multi-stage compression and intercooling for low temperature waste heat recovery

For low temperature waste heat recovery, CO2 is preferred as the working fluid due to its low critical temperature and easy availability. However, a major limitation of CO2 based power plant with low temperature waste heat recovery is temperature of heat rejection. In the present work, a study has been made to explore possible improved performance of a CO2 power cycle using low temperature waste heat through multi-stage compression and intercooling. A thermodynamic model has been developed to analyze effects of various operating parameters on the performance of a CO2 power cycle with two or more stages of compression and intercooling. Most significant observation is the existence of an optimum combination of the lowest cycle pressure and the intermediate pressure for either maximum specific power output or 2nd law efficiency of the CO2 power cycle with two-stage compression and intercooling. (C) 2015 Elsevier Ltd. All rights reserved.