Exergy Analysis of Combined Organic And Lng Rankine Cycles With Different Source Temperatures
The performance of power generation system can be improved by using liquefied natural gas (LNG) cold energy and thus the utilization of LNG cold energy has been an interesting area of study. In this paper an exergetical analysis is carried out for a combined cycle of an organic Rankine cycle (ORC) and a LNG Rankine cycle utilizing low-grade heat source in the form of sensible energy. The effects of the system parameters such as turbine inlet pressure of the working fluid or source temperature on the exergy destruction at each component as well as the total exergy efficiency are investigated extensively. The results indicate that the greatest exergy destruction ratio of the system depends on the reduced turbine inlet pressure and source temperature. The exergy efficiency decreases for low source temperature but increases for high source temperature as the turbine inlet pressure increases.
Keywords- Organic Rankine Cycle (ORC), Liquefied Natural Gas (LNG), Exergy, Exergy Destruction, Exergy Efficiency