Productivity intensification of humidification–dehumidification desalination unit by using pulsed water flow regime

This work investigates the possibility of using pulsating liquid flow for improving the performance of humidification–dehumidification desalination unit. The results showed that the unit productivity has been increased by increasing the off time i.e. decreasing the frequency of pulsed water flow up to certain levels, a frequency of 20/60 on/off time was found to have the highest productivity of the unit. Increasing the amplitude of water pulsation (water flow per pulse) was found to increase the unit productivity as well. Other variables such as inlet water temperature, and air flow rate were investigated. The heat and mass transfer analysis of the humidification unit was carried out, the results showed that the experimental value of hyMky is higher than the predicted one. In addition analysis of the dehumidification unit was carried out, the results showed that the unit productivity has been increased by increasing the inlet cooling water flow rate and that the overall heat transfer coefficient (U) was found to be 38.25 W/m2.K which is considered within the range of industrial air water heat transfer units.