Experimental investigation of heat recovery in a humidification-dehumidification desalination system via a heat pump

A hybrid HDH desalination system integrated with a heat pump was experimentally studied. In this system, heat pump's heating was used to raise the temperature of the air entering the humidifier and its cooling effect was used for dehumidification of humid air and freshwater production. In other words, heat pump's condenser works as the heater of the HDH cycle and its evaporator works as the coolant for the dehumidifier of HDH cycle. The effects of different parameters such as mass flow rate of inlet saline water (relative humidity of the air passing the dehumidification section), volume flow rate of the air passing the dehumidification section and ambient air temperature on freshwater production and GOR were investigated. Analyzing the experimental results indicated that the highest yield and GOR reaches 2.79 kg/h and 2.08, respectively. It was also observed that increasing the relative humidity and volume flow rate of the air passing the dehumidification section results in higher GOR values for the system. Additionally, it was seen that raising the ambient temperature leads to a reduction in the system's GOR. The economic analysis showed that the CPL of the current study is 0.0114 $/L.