Design and simulation of water‐cooled dehumidifier for HDH desalination plant

Abstract

Condensers are widely used in thermal applications to transfer the maximum heat between the working fluids and change the phase of vapor. In basic thermal‐based humidification–dehumidification (HDH) desalination, a condenser is used as a water‐cooled dehumidifier for improving freshwater production within the minimum area. In this thermal‐based HDH system, desalinated water production is the major output. The simulation tool is used to analyze the thermohydraulic performance of a water‐cooled dehumidifier. In this thermohydraulic analysis, variables, like, airflow rate, tube diameter, and longitudinal pitch are thoroughly investigated to identify the optimum parameters for improving the performance of the water‐cooled dehumidifier. The obtained results indicate that the heat transfer area and performance index are increased when the airflow rate and tube diameter change. But at 8 and 10 mm tube diameter, the surface area and performance index are contradictory in nature while longitudinal pitch varies from 30 to 45 mm. At 12.5 mm tube diameter, surface area and performance index decrease gradually but the certain period of pitch limit performance increases markedly. In addition, the yield of HDH desalination has been investigated. When the mass flow rate changed from 100 to 500 kg/h, it was 0.667–3.32 L/h.