Energy and exergy analysis of Derna steam power plant and the impact of varying the different parameters on exergy destruction

Abstract

In this study, an energy and exergy analysis of the Derna steam power plant in Libya is presented. This study aims to identify the components with high energy and exergy losses which are leading to a decrease in the performance of the power plant. The largest place losses can be figured out hence to subsequently ensure where the greatest margin for improvement would be incurred. The influence of different parameters, such as temperatures and pressure values, on this analysis, is also conducted via the so-called Engineering Equation Solver software (EES). In terms of energy, the condenser is found to majorly have the highest energy losses of approximately 103MW which is received by the environment whilst the boiler losses are recorded to be about 24MW. As far as exergy is concerned, the boiler system is found to have the highest percentage ratio of exergy destruction to overall exergy destruction of 88 %, followed by the turbine of 8% and then the condenser of 3%. In addition, the thermal efficiency is also calculated based on the lower heating value of fuel and found to be 29% whereas the exergy efficiency of the power cycle is then computed to be 27.19%. The study is further concluded the significant effect of the live steam temperature changes concerning the design value, the high pressure heater (HPH) pressure as well as the condenser pressure on exergy destruction.