Optimized solar-powered liquid desiccant system to supply building fresh water and cooling needs

This paper studies the feasibility of using a solar-powered liquid desiccant system to meet both building cooling and fresh water needs in Beirut humid climate using parabolic solar concentrators as a heat source for regenerating the liquid desiccant. The water condensate is captured from the air leaving the regenerator. An integrated model of solar-powered calcium chloride liquid desiccant system for air dehumidification/humidification is developed. The LDS model predicted the amount of condensate obtained from the humid air leaving the regenerator bed when directed through a coil submerged in cold sea water. An optimization problem is formulated for selection and operation of a LDS to meet fresh water requirement and air conditioning load at minimal energy cost for a typical residential space in the Lebanon coastal climate with conditioned area of 80 m(2) with the objective of producing 15 I of fresh drinking water a day and meet air conditioning need of residence at minimum energy cost. The optimal regeneration temperature increases with decreased heat sink temperature with values of 50.5 degrees C and 52 degrees C corresponding to sink temperatures of 19 degrees C and 16 degrees C. (C) 2011 Elsevier Ltd. All rights reserved.