Conventional and advanced exergetic and exergoeconomic analyses applied to a tri-generation cycle for heat, cold and power production

• A tri-generation cycle is analyzed using advanced exergoeconomic concepts.
• 29% of the total exergy destruction in the cycle is endogenous-avoidable.
• 29% of cost rates associated with exergy destruction is endogenous-avoidable.
• New exergoeconomic concept provide valuable information for improving the system.
• Refrigeration cycle components have the lowest values of the exergoeconomic factor.

New exergetic concepts such as endogenous/exogenous and avoidable/unavoidable exergy destruction and new exergoeconomics ideas provide valuable information about the potential of optimization of the system. In this work, a tri-generation cycle, with 30 MW power production, 40 MW heat generation and 2 MW cooling capacity, is analyzed by conventional and new exergetic and exergoeconomic concepts. It is found from the whole cycle analysis that an amount of almost 29% of the total exergy destruction and overall cost rates associated with exergy destruction in the cycle are endogenous-avoidable. Both conventional and advanced exegy analyses suggest that the combustion chamber has the highest contribution on the overall exergy destruction and the cost rates associated with exergy destruction of the cycle. In HRSG, over 71% of the exergy destruction is unavoidable. Air pre-heater is introduced with the higher improvement priority compared to HRSG. Also, a new definition for the exergoeconomic factor is introduced which suggests that the components of refrigeration cycle and combustion chamber have the lowest values of the exergoeconomic factor, therefore, the corresponding exergy destruction cost rates should be reduced. It is concluded that employing the new exergetic and exergoeconomic concepts provide valuable information for improving the overall system.