Abstract
Unlike most waste heat recovery, LNG is a multi-component mixture, low temperature and wide boiling range make it difficult to achieve efficient recovery of cold energy with a conventional single-stage Rankine cycle. On the other hand, with the stricter restrictions on hydrofluorocarbons under the Kigali Amendment, more environmentally friendly natural refrigerants deserve more attention as alternatives. Therefore, to improve the recovery efficiency of cold energy, this paper studied the optimal natural refrigerant combination of two-stage Rankine cycle LNG cold energy power generation system, and analyzed the performance characteristics and influencing factors of the system. In addition, in order to verify the application potential of the system, the levelized cost of electricity and payback period of the system for different refrigerant combinations were also analyzed. The results show that at a delivery pressure of 0.6 MPa, the refrigerant combination of ‘ethylene + propane’ has the best power generation performance, with a net generation and exergy efficiency of 9020.8 kW and 35.54 %, respectively. The refrigerant combination of ‘ethylene + propylene’ has the best economic performance, with a levelized power cost and payback period of 0.0355 USD/kWh and 2.76 years, respectively. In the case of high delivery pressure requirements, ‘ethane + propane’ becomes the optimal refrigerant combination, which can simultaneously achieve optimal power generation performance and economic performance. In addition, as the delivery pressure decreases, the power generation and economic performance of the system will improve. It is also found that among all refrigerants, ethane and ethylene have the highest evaporation pressure, which is conducive to obtaining a greater effective enthalpy drop, but the required superheat is also larger, which reduces the heat transfer efficiency of the evaporator to a certain extent.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
