An experimental investigation on a portable bubble basin humidification/dehumidification desalination unit utilizing a closed-loop pulsating heat pipe

The present work aims to enhance the performance of a solar energy-driven HDH desalination system. An experimental apparatus consisting of a novel closed-loop pulsating heat pipe (CLPHP) assisted by a bubble basin HDH system was investigated. To evaluate the productivity of the fresh water, tests have been properly designed and conducted in outdoor and indoor modes during June and July of 2020, under local weather conditions of Mashhad, Iran. A closed air-heated configuration is introduced into the HDH desalination system, to recover the condensation latent heat. The air leaving the dehumidifier is pre-heated and pre-humidified using CLPHP before entering the humidifier of the desalination unit. Also, an air injection system is used to enhance the mass and heat transfer rate by generating bubbles. In the experiments, the influence of the operating conditions such as radiation and air mass flow rate on the performance of the desalination unit was investigated. Furthermore, a comparison between the bubble basin and bubble column types was carried out. Based on the results, the bubble basin type presented a higher yield compared to the bubble column type that was obtained as 0.83 and 0.70 (kg/(hr.m(2))), respectively. Besides, it was observed that by increasing the radiation and air mass flow rate, productivity is improved. The maximum obtained yield of the proposed system was achieved as 8.7 L/(day.m(2)).