Methods and systems for liquid desiccant air conditioning system retrofit

Abstract

Methods and systems are disclosed for utilizing liquid desiccant air conditioning systems in connection with existing HVAC equipment to achieve reductions in electricity consumption.

1 . A liquid desiccant air conditioning unit for treating an air stream entering a building space, comprising:
 a conditioner including a plurality of structures arranged in a substantially vertical orientation, each structure having at least one surface across which a liquid desiccant can flow, wherein the air stream flows between the structures such that the liquid desiccant dehumidifies the air stream in a warm weather operation mode and humidifies the air stream in a cold weather operation mode, each structure further includes a desiccant collector at a lower end of the at least one surface for collecting liquid desiccant that has flowed across the at least one surface of the structure;   a tub module coupled to the conditioner comprising interior and exterior walls forming a hollow shell structure, wherein the air stream treated by the conditioner flows through an interior space in the tub module defined by the interior walls, and wherein liquid desiccant used in the conditioner flows through a space between the interior and exterior walls of the tub module;   an apparatus for moving the air stream through the conditioner and tub module and into the building; and   an apparatus for circulating the liquid desiccant through the conditioner.   
     
     
         2 . The liquid desiccant air-conditioning unit of  claim 1 , wherein the liquid desiccant air-conditioning unit is modular and can be coupled to one or more additional liquid desiccant air-conditioning units to increase air conditioning capacity, wherein a first duct is coupled to each of the liquid desiccant air-conditioning units to distribute the air stream among the liquid desiccant air-conditioning units, and wherein the tub modules of the liquid desiccant air-conditioning units are connected in series to collect and transfer air treated by the liquid desiccant air-conditioning units to the building. 
     
     
         3 . The liquid desiccant air-conditioning unit of  claim 1 , wherein the apparatus for moving the air stream comprises a fan or a blower. 
     
     
         4 . The liquid desiccant air-conditioning unit of  claim 1 , wherein the apparatus for circulating the liquid desiccant comprises a pump. 
     
     
         5 . The liquid desiccant air-conditioning unit of  claim 1 , wherein each of the plurality of structures in the conditioner includes a passage through which a heat transfer fluid can flow. 
     
     
         6 . The liquid desiccant air-conditioning unit of  claim 1 , wherein each of the plurality of structures in the conditioner includes a sheet of material positioned proximate to the outer surface of each structure between the liquid desiccant and an air stream, said sheet of material permitting transfer of water vapor between the liquid desiccant and an air stream. 
     
     
         7 . The liquid desiccant air-conditioning unit of  claim 6 , wherein the sheet of material comprises a membrane. 
     
     
         8 . The liquid desiccant air-conditioning unit of  claim 1 , wherein the conditioner is mounted on top of the tub module. 
     
     
         9 . A regenerator unit in a liquid desiccant air conditioning system, comprising:
 a regenerator including a plurality of structures arranged in a substantially vertical orientation, each structure having at least one surface across which a liquid desiccant can flow, wherein an air stream flows between the structures such that the liquid desiccant humidifies the air stream in a warm weather operation mode and dehumidifies the air stream in a cold weather operation mode, each structure further includes a desiccant collector at a lower end of the at least one surface for collecting liquid desiccant that has flowed across the at least one surface of the structure;   a tub module coupled to the regenerator comprising interior and exterior walls forming a hollow shell structure, wherein the air stream to be treated by the regenerator flows into the regenerator through an interior space in the tub module defined by the interior walls, and wherein liquid desiccant used in the regenerator flows through a space between the interior and exterior walls of the tub module;   an apparatus for moving the air stream through the regenerator and tub module; and   an apparatus for circulating the liquid desiccant through the regenerator.   
     
     
         10 . The regenerator unit of  claim 9 , wherein the regenerator unit is modular can be coupled to one or more additional regenerator units to increase air conditioning capacity, wherein a first duct is coupled to each of the regenerator units to collect and transfer air out air treated by the regenerator units, and wherein the tub modules of the regenerator units are connected in series to distribute air to be treated by the regenerator units. 
     
     
         11 . The regenerator unit of  claim 9 , wherein the apparatus for moving the air stream comprises a fan or a blower. 
     
     
         12 . The regenerator unit of  claim 9 , wherein the apparatus for circulating the liquid desiccant comprises a pump. 
     
     
         13 . The regenerator unit of  claim 9 , wherein each of the plurality of structures in the regenerator includes a passage through which a heat transfer fluid can flow. 
     
     
         14 . The regenerator unit of  claim 9 , wherein each of the plurality of structures in the regenerator includes a sheet of material positioned proximate to the outer surface of each structure between the liquid desiccant and an air stream, said sheet of material permitting transfer of water vapor between the liquid desiccant and an air stream. 
     
     
         15 . The regenerator unit of  claim 14 , wherein the sheet of material comprises a membrane. 
     
     
         16 . The regenerator unit of  claim 9 , wherein the regenerator is mounted on top of the tub module. 
     
     
         17 . A desiccant air conditioning system for treating an air stream entering a building space, comprising: a conditioner including a plurality of first structures arranged in a substantially vertical orientation, each structure having at least one surface across which a liquid desiccant can flow, each structure also including a passage through which heat transfer fluid can flow, wherein the air stream flows between the structures such that the liquid desiccant dehumidifies and cools the air stream, and the heat transfer fluid cools the liquid desiccant;
 a regenerator connected to the conditioner for receiving liquid desiccant from the conditioner and causing the liquid desiccant to desorb water;   an indirect evaporative cooling unit coupled to the conditioner for receiving the heat transfer fluid that has flowed through the first structures and a portion of the air stream that has been dehumidified and cooled by the conditioner, said indirect evaporative cooling unit including a plurality of second structures arranged in a substantially vertical orientation, each structure having at least one surface across which water is flowed, each structure also including a passage through which the heat transfer fluid from the conditioner is flowed, wherein the portion of the air stream received from the conditioner flows between the structures such that the water is evaporated into the air stream, resulting in cooling of the heat transfer fluid, and wherein the cooled heat transfer fluid is returned to the conditioner;   an apparatus for moving the air stream through the conditioner and indirect evaporative cooling unit;   an apparatus for circulating the liquid desiccant through the conditioner and regenerator; and   an apparatus for circulating heat transfer fluid through the conditioner and the indirect evaporative cooling unit.   
     
     
         18 . The system of  claim 17 , wherein up to 30% of the air stream treated by the conditioner is diverted to the indirect evaporative cooling unit. 
     
     
         19 . The system of  claim 17 , wherein each of the plurality of second structures in the indirect evaporative cooling unit includes a sheet of material positioned proximate to the outer surface of each structure between the water and the air stream, said sheet of material permitting transfer of water vapor to the air stream. 
     
     
         20 . The system of  claim 17 , wherein the sheet of material comprises a membrane. 
     
     
         21 . The system of  claim 17 , wherein the water comprises seawater, wastewater, or drinking water. 
     
     
         22 . The system of  claim 17 , wherein the water comprises seawater, wastewater, or drinking water. 
     
     
         23 . The system of  claim 17 , wherein each of the plurality of first structures in the conditioner includes a sheet of material positioned proximate to the outer surface of each structure between the liquid desiccant and the air stream, said sheet of material permitting transfer of water vapor between the liquid desiccant and the air stream. 
     
     
         24 . The system of  claim 23 , wherein the sheet of material comprises a membrane.