Air energy reduction method and apparatus using waste heat from condensers or other low grade heat

Abstract

The present invention provides a process for utilizing waste heat released by condensers of conventional air conditioning systems and more particularly using this low grade heat or other low grade sources that are slightly above ambient air temperatures to alter concentration of a liquid desiccant that contacts an ambient air stream thereby reducing its relative humidity while its temperature is controlled and generally reduced by heat exchange with another air stream that is saturated with water.

1 . Apparatus comprising:
 a first chamber containing a first air flow device forming a first air flow of ambient air through the first chamber;   a second chamber containing a second air flow device forming a second air flow through the second chamber, the air flow countercurrent to the first air flow;   a third chamber receiving a third air flow flowing through the third chamber from a compressor driven air conditioner condenser;   the first chamber having a plurality of first stages, the stages containing a liquid desiccant, the liquid desiccant passing through each stage counter-currently to the first air flow while in contact with the first air flow in each stage;   a second chamber having a plurality of second stages, the stages containing water, the water being in contact with the second air flow in each stage:   the third chamber having a plurality of third stages, the stages containing a liquid desiccant, the liquid desiccant passing through each stage counter-currently to the third air flow while in contact with the third air flow in each stage;   the first air stream dehumidified by the liquid desiccant, the liquid desiccant becoming dilute passing through the first chamber;   the first stages of the first chamber in thermal association with the corresponding second stages of the second chamber by means of heat exchange between the liquid desiccant and water, the water receiving heat developed in the first chamber during dehumidification of the first air stream; and   the dilute desiccant from the first chamber flowing to the third chamber, the third air stream receiving heat from the condenser causing evaporation from the desiccant passing through the third stages with the concentrated desiccant returned to the first chamber.   
   
   
       2 . Apparatus, comprising:
 a first chamber containing a first air flow device forming a first air flow of ambient air through the first chamber;   a second chamber containing a second air flow device forming a second air flow through the second chamber, the air flow countercurrent to the first air flow;   a third chamber containing a third air flow device receiving heat from a heat source forming a third air flow through the third chamber;   the first chamber having a plurality of first stages, the stages containing a liquid desiccant, the liquid desiccant passing through each stage counter-currently to the first air flow while in contact with the first air flow in each stage;   a second chamber having a plurality of second stages, the stages containing water, the water being in contact with the second air flow in each stage:   the third chamber having a plurality of third stages, the stages containing a liquid desiccant, the liquid desiccant passing through each stage counter-currently to the third air flow while in contact with the third air flow in each stage;   the first air stream dehumidified by the liquid desiccant, the liquid desiccant becoming dilute passing through the first chamber;   the first stages of the first chamber in thermal association with the corresponding second stages of the second chamber by means of heat exchange between the liquid desiccant and water, the water receiving heat developed in the first chamber during dehumidification of the first air stream; and   the dilute desiccant from the first chamber flowing to the third chamber, the third air stream receiving heat from the heat source causing evaporation from the desiccant passing through the third stages with the concentrated desiccant returned to the first chamber.   
   
   
       3 . A process, comprising:
 dehumidifying an ambient air stream in a staged manner by means of a liquid desiccant exposed to this air stream in each stage causing absorption of water from this air stream;   transferring heat from this dehumidification to a another air stream exposed to water in a staged manner causing evaporation of water into this air stream in each stage; and   subjecting the desiccant containing the absorbed water to a heated air stream in a staged manner to evaporate water from the desiccant in each stage.