A novel integration of oxy-fuel cycle, high temperature solar cycle and LNG cold recovery – energy and exergy analysis

Abstract

A novel integrated CO2 oxy-fuel transcritical and Rankine cycles with CO2 capturing is introduced and analyzed. Carbon dioxide (CO2) is used as working fluid which is extracted from the process in high pressure and liquid state. The process benefits from high-temperature solar cycle as heat source and LNG cold energy as heat sink. Solar energy is used in the oxy-fuel transcritical cycle as the evaporator heat source. In the same context, the required heat duty for LNG vaporization in the desired operating condition is provided by solar energy. 1.03×104kg·h−1 of CO2 is condensed by employing cold energy of LNG which increases the net electrical power. Parametric analysis is conducted for turbine inlet temperature (TIT), LNG flow rate and solar cycle operating parameters. Energy and exergy analysis are done to find out the better performance of the process. The obtained results indicate that, TIT and LNG flow rate have positive effects on the exergy efficiency and net electrical power generation. Also, by applying TIT about=900°C, concentrated parabolic collector area (ACPC) equal to 4.6m2, 3.89×105kg·h−1 of LNG and 7.13×104kW of absorbed high-temperature solar energy; the net electrical power about 43.5×103kW is generated. The energy and exergy efficiencies of the overall process are 57.2% and 60.7%, respectively.