Conventional and Advanced Exergy and Exergoeconomic Assessment of an Optimized System Consisting of Kalina and Organic Rankine Cycles for Waste Heat Recovery

The use of different technologies to recover the waste heat from various sources is receiving a wide currency worldwide. The current study proposes a Kalina-organic Rankine cycle (ORC)-based system in order to make use of the exhaust gas and the jacket cooling water of an existing diesel engine. First, the system is optimized to generate maximum power. Then, the optimum system is subjected to both conventional and advanced analyses investigating its exergy and exergoeconomic aspects. Hence, the real sources of inefficiency and chances of enhancement are revealed. The system can produce 69.7 kW power with energy and exergy efficiencies of 22.3% and 59.2%, respectively. The Kalina steam generator has the most irreversibility share in the system; however, when it comes to the real potential of improvement, the Kalina turbine ranks the first that can benefit the entire system. Moreover, the results of both conventional and advanced exergoeconomic analyses indicate the Kalina turbine is the most highlighted component that both needs and can be improved in terms of cost rates. In the end, a comparison between the different results and approaches is made to summarize the results.