Cost evaluation of exergy destruction of an absorption chiller in a cogeneration system

Abstract

This paper evaluates the exergy destruction costs of the components of an absorption chiller driven by the exhaust gases of three natural gas engines in a cogeneration system. For the evaluation, the chiller's energetic, exergetic, and exergoeconomic models are established and solved in the Engineering Equation Solver (EES) software. Also, the factors contributing to decreasing the costs of thermodynamic inefficiencies within the chiller components are investigated. The results show that the generator and absorber are the components that involve the highest exergy destruction, reaching up to 58.19% and 19.49% of the total exergy destruction of the chiller. Also, these components are the ones that reach the highest rates of exergy destruction costs, 80.89 $/h and 65.77 $/h. In this way, the exergoeconomic factor indicates that the generator, absorber, and evaporator have the most significant opportunities to reduce exergy destruction costs. Operating the chiller at a higher generator temperature could reduce exergy destruction costs by $17/h in the generator. Operating the chiller at a temperature of 37 °C in the condenser and absorber could decrease exergy destruction costs in the evaporator by up to $15/h.