Humidity water vapour collection by absorption cooling machines

Abstract

This paper presents a non-conventional method for producing fresh water by collecting the humidity water vapour in humid hot climates as a by-product of a comfort conditions creating system. This is achieved by employing a LiBrH 2O absorption cooling machine with an open absorber where the outside ventilation air is brought in direct contact with the absorbent concentrated solution. Consequently the air is dehumidified and the diluted solution is regenerated in the generator at a moderate temperature level. The concentrated solution repeats the dehumidification process while the vapour released (humidity) is used to fire two generators at lower pressures to promote the required cooling effect in the evaporator and the condensed vapour represents the fresh water by-product of the system. The present system is thermodynamically analysed and is compared with an absorption machine with a closed absorber. Whenever the system is supplied by hot water at 140°C, it exhibits an overall COP of 1.63 which is 54 percent more than the closed absorber machine and 30.5 percent more than an existing double effect absorption machine. As a case study, the system is powered by solar energy for a day school air-conditioning. Results showed that beside airconditioning, the system can provide about 38 percent of the daily water requirement for the school students at a daily production slightly higher than solar still basins.