Exergoeconomic analysis and optimization of a hybrid Kalina and humidification-dehumidification system for waste heat recovery of low-temperature Diesel engine

Internal combustion engines are of the important systems with extensive applications in power generation and agricultural/industrial machines and vehicles due to their promising features such as high thermal efficiency, and reliability. The reuse of the exhaust gas and jacket water waste heat is an effective method to improve engine performance and decrease fuel consumption and environmental pollution. In this paper, to recover the waste heat of a diesel engine, cogeneration of electrical power and freshwater is proposed. The Kalina cycle is used for power generation through the utilization of exhaust gas energy, and for freshwater production, the HDH system is employed using jacket water energy. Thermodynamic and exergoeconomic analysis and optimization are applied to the proposed system. The effect of several parameters on net output power, exergy efficiency, HDH unit performance, and the sum unit cost of the system's product is studied. The comparison of the Multi-objective optimization results with the base case outcomes betokens that the thermal efficiency and exergy efficiency are improved by 1.88% and 1.52%, respectively. Moreover, the SUCP value is reduced by 0.94 $/GJ. For the electricity sale price of 0.09 $/kWh, the payback period is estimated 7.2 years, and the NPV at the end of the plant's life obtained 165,814 $.