Analysis of a novel solid desiccant evaporative cooling system integrated with a humidification-dehumidification desalination unit

Abstract

A new configuration of a solid desiccant evaporative cooling system integrated with a humidification-dehumidification (HDH) desalination unit was proposed, and its performance was numerically evaluated. In the proposed system, the humid exhaust air from the desiccant wheel and M-cycle IEC was recycled and supplied to an HDH unit to improve the water production rate. Two operation modes were proposed depending on climate conditions. The system with two operation modes was evaluated under various operating conditions. A case study was performed under Australian climatic conditions. The results showed that Mode 1 had a better cooling performance than Mode 2, with a maximum cooling capacity of 4.76 kW. However, Mode 2 was more energy efficient, with an average COP of 0.71, as no regeneration heat was needed. With the HDH unit, the freshwater produced by the system could fully cover the water usage of the M-cycle IEC in both modes. When the heat source temperature of the HDH unit increased to 70 °C, the water productivity of the system could reach 148.5 kg/h and 42.0 kg/h for Mode 1 and 2, respectively. The findings indicated that the proposed system had good potential for producing freshwater and cooling simultaneously.