CO2-N2를 이용한 천연가스 액화사이클의 성능평가

Abstract

This paper presents a new natural gas liquefaction cycle which utilizes carbon dioxide(CO2)and nitrogen gas(N2) cycles. The liquefaction cycle with staged compression was designed and simulated using the HYSYS software for improving cycle efficiency. This included a cascade cycle with a three-stage compression consisting of a CO2 and a N2 cycle. These cycles were compared with an optimized staged compression process. The Compressor work, specific energy, and COP (Coefficient of Performance) of the cascade cycles were compared and analyzed. In this study, using C3H8-C2H4-CH4 cycle heat exchanger design of LNG and natural gas at a pressure drop of liquefaction cycle, the impact on the identified results, the following conclusions were obtained. Refrigerant pressure drop due to the increase of natural gas, an Compressor work, the average growth rate of 3.8% was shown, specific power showed that the average increased by 3.8%. Using C3H8-C2H4-CH4 cycle is based on the newly proposed CO2-C2H6-N2 and CO2-N2 cycle performance of liquid was analyzed whether the exergy. In other words, the refrigerant type, number of streams, the number of compressors, LNG compared the number of heat exchangers, compressor work, COP, compared to specific energy value and also, in addition, by comparing the loss of exergy within the cycle and then the following conclusions were obtained. CO2-N2 cycle as the two existing three sectors responsible for the temperature of refrigerant existing in the C3H8-C2H4-CH4 by less than a high compression efficiency and the amount shown. However, future improvements than N2, if the efficiency of the cycle configuration of the device in a smaller unit less trouble, because there are advantages of a simple liquid cycle where space is limited liquefaction cycle for LNG-FPSO is considered as a suitable.