Exergoeconomic assessment and optimization of a double effect absorption chiller integrated with a humidification-dehumidification desalination system

Abstract Combined absorption cooling device and humidification-dehumidification desalination component is newly proposed to be an alternative system to substitute the existing individual conventional arrangement for the betterment of energy usage. Specifically, among many waste heat recovery technologies, the combination of cooling and humidification-dehumidification processes is an innovative thought to implement a new thermodynamic system for improving the overall system performance. To be successful implementation of this innovation concept, in this study, both the above systems are combined to produce simultaneously 150 kW cooling effect and 0.1 kg s−1 freshwater production. This combined system also improves the effective use of waste heat. A parametric study of the proposed system is carried out to determine the optimum operational effect by varying different design constants based on the energy, exergy, and economic analyses. A multi-objective optimization model is also developed using the non-dominated storing genetic algorithm (NSGA-II) to obtain the minimum operating cost. In the optimization study, the total exergy efficiency is considered to be a maximization function and the total product cost is treated as a minimization objective. The results obtained from the exergy and economic studies reveal that the cooling assembly is the primary source for the irreversibility production with the exergy destruction rate of 17.0415 kW. Also, the exergoeconomic factor of humidifier is the lowest one (0.94%). From the multi-objective optimization, the total exergy efficiency and the total product cost are calculated as 0.5014 and 68.1680 $ GJ−1, respectively. At the optimum operating condition, calculated values of the gained output ratio (GOR) and coefficient of performance (COP) are 2.0181 and 1.2474, respectively. Furthermore, the present combined system is compared with the traditional humidification-dehumidification desalination system. This comparison highlights that the GOR of the proposed system is about 140% higher than the traditional system. Therefore, there is no doubt to be arising in mind that the operation of the proposed system produces more beneficial thermal aspects in comparison to the existing system.