Methods and systems for mini-split liquid desiccant air conditioning

Abstract

A split liquid desiccant air conditioning system is disclosed for treating an air stream flowing into a space in a building. The split liquid desiccant air-conditioning system is switchable between operating in a warm weather operation mode and a cold weather operation mode.

1 . A split liquid desiccant air conditioning system for treating an air stream flowing into a space in a building, said split liquid desiccant air-conditioning system being switchable between operating in a warm weather operation mode and a cold weather operation mode, the split liquid desiccant air conditioning system comprising:
 a conditioner located inside the building, said 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, each structure also including a passage through which a heat transfer fluid can flow, wherein the air stream to be treated flows between the structures such that the liquid desiccant dehumidifies and cools the air stream in the warm weather operation mode and humidifies and heats the air stream in the cold weather operation mode, the conditioner further comprising a sheet of material positioned proximate to the at least one 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;   a regenerator located outside the building connected to the conditioner by liquid desiccant pipes for exchanging liquid desiccant with the conditioner, said regenerator including a plurality of structures arranged in a substantially vertical orientation, each structure having at least one surface across which the liquid desiccant can flow, each structure also including a passage through which a heat transfer fluid can flow, said regenerator causing the liquid desiccant to desorb water in the warm weather operation mode and to absorb water in the cold weather operation mode to or from an air stream flowing through the regenerator;   a reversible heat pump located outside the building coupled to the conditioner and to the regenerator by heat transfer fluid pipes, wherein the heat pump pumps heat from the heat transfer fluid flowing in the conditioner to the heat transfer fluid flowing in the regenerator in the warm weather operation mode, and wherein the heat pump pumps heat from the heat transfer fluid flowing in the regenerator to the heat transfer fluid flowing in the conditioner in the cold weather operation mode;   an apparatus for moving the air stream through the conditioner;   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 reversible heat pump; and   an apparatus for circulating heat transfer fluid through the regenerator and the reversible heat pump.   
     
     
         2 . The system of  claim 1 , wherein the reversible heat pump comprises a refrigerant evaporator heat exchanger. 
     
     
         3 . The system of  claim 1 , wherein the liquid desiccant pipes comprise a first pipe for transferring liquid desiccant from the conditioner to the regenerator and a second pipe for transferring liquid desiccant from the regenerator to the conditioner, wherein the first and second pipes are in close thermal contact to facilitate heat transfer from the liquid desiccant flowing in one of the first and second pipes to the liquid desiccant flowing in the other of the first and second pipes. 
     
     
         4 . The system of  claim 3 , wherein the first and second pipes comprise an integrally formed structure. 
     
     
         5 . The system of  claim 4 , wherein the integrally formed structure comprises a polymer material. 
     
     
         6 . The system of  claim 5 , wherein at least a wall of the structure between the first and second pipes comprises a thermally conductive polymer. 
     
     
         7 . The system of  claim 1 , wherein the conditioner is mounted on a wall inside the building. 
     
     
         8 . The system of  claim 1 , wherein the conditioner has a generally flat configuration adapted to be hidden behind a computer display, television, or painting. 
     
     
         9 . The system of  claim 1 , further comprising one or more additional conditioners in the building, each coupled to the regenerator and the heat pump. 
     
     
         10 . A split liquid desiccant air conditioning system for cooling and dehumidifying an air stream flowing into a space in a building, the split liquid desiccant air conditioning system comprising:
 a conditioner located inside the building, said 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 a heat transfer fluid can flow, wherein the air stream flows between the structures such that the liquid desiccant dehumidifies and cools the air stream, the conditioner further comprising a sheet of material positioned proximate to the at least one 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;   a regenerator located outside the building connected to the conditioner by liquid desiccant pipes for exchanging liquid desiccant with the conditioner, said regenerator including a plurality of second structures arranged in a substantially vertical orientation, each structure having at least one surface across which the liquid desiccant can flow, each structure also including a passage through which a heat transfer fluid can flow, said regenerator causing the liquid desiccant to desorb water to an air stream flowing through the regenerator;   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 third 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 by the air stream, resulting in cooling of the heat transfer fluid which is returned to the conditioner, and wherein the air stream treated by the indirect evaporative cooling unit is exhausted to the atmosphere;   an apparatus for moving the air stream through the conditioner and the 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; and   a heat source for heating the heat transfer fluid in the regenerator.   
     
     
         11 . The system of  claim 10 , wherein the liquid desiccant pipes comprise a first pipe for transferring liquid desiccant from the conditioner to the regenerator and a second pipe for transferring liquid desiccant from the regenerator to the conditioner, wherein the first and second pipes are in close contact to facilitate heat transfer from the liquid desiccant flowing in one of the first and second pipes to the liquid desiccant flowing in the other of the first and second pipes. 
     
     
         12 . The system of  claim 11 , wherein the first and second pipes comprise an integrally formed structure. 
     
     
         13 . The system of  claim 12 , wherein the integrally formed structure comprises a polymer material. 
     
     
         14 . The system of  claim 13 , wherein at least a wall of the structure between the first and second pipes comprises a thermally conductive polymer. 
     
     
         15 . The system of  claim 10 , wherein the conditioner is mounted on a wall inside the building. 
     
     
         16 . The system of  claim 10 , wherein the conditioner has a generally flat configuration adapted to be hidden behind a computer display, television, or painting. 
     
     
         17 . The system of  claim 10 , wherein the indirect evaporative cooling unit is located inside the building. 
     
     
         18 . The system of  claim 10 , wherein the indirect evaporative cooling unit is located outside the building. 
     
     
         19 . The system of  claim 10 , wherein the heat source for heating the heat transfer fluid in the regenerator comprises a gas water heater, a solar module, a solar thermal/photovoltaic module, or a steam loop. 
     
     
         20 . A split liquid desiccant air conditioning system for heating and humidifying an air stream flowing into a space in a building, the split liquid desiccant air conditioning system comprising:
 a conditioner located inside the building, said 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 a heat transfer fluid can flow, wherein the air stream flows between the structures such that the liquid desiccant humidifies and heats the air stream, the conditioner further comprising a sheet of material positioned proximate to the at least one 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;   a regenerator located outside the building connected to the conditioner by liquid desiccant pipes for exchanging liquid desiccant with the conditioner, said regenerator including a plurality of second structures arranged in a substantially vertical orientation, each structure having at least one surface across which the liquid desiccant can flow, each structure also including a passage through which a heat transfer fluid can flow, said regenerator causing the liquid desiccant to absorb water from an air stream flowing through the regenerator;   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 humidified and heated by the conditioner, said indirect evaporative cooling unit including a plurality of third 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 vapor is evaporated from the water, resulting in humidification of the air stream, and wherein the air stream treated by the indirect evaporative cooling unit is exhausted inside the building;   an apparatus for moving the air stream through the conditioner and the 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; and   a heat source for heating the heat transfer fluid in the conditioner and the indirect evaporative cooling unit.   
     
     
         21 . The system of  claim 20 , wherein the liquid desiccant pipes comprise a first pipe for transferring liquid desiccant from the conditioner to the regenerator and a second pipe for transferring liquid desiccant from the regenerator to the conditioner, wherein the first and second pipes are in close contact to facilitate heat transfer from the liquid desiccant flowing in one of the first and second pipes to the liquid desiccant flowing in the other of the first and second pipes. 
     
     
         22 . The system of  claim 21 , wherein the first and second pipes comprise an integrally formed structure. 
     
     
         23 . The system of  claim 22 , wherein the integrally formed structure comprises a polymer material. 
     
     
         24 . The system of  claim 23 , wherein at least a wall of the structure between the first and second pipes comprises a thermally conductive polymer. 
     
     
         25 . The system of  claim 20 , wherein the conditioner is mounted on a wall inside the building. 
     
     
         26 . The system of  claim 20 , wherein the conditioner has a generally flat configuration adapted to be hidden behind a computer display, television, or painting. 
     
     
         27 . The system of  claim 20 , wherein the indirect evaporative cooling unit is located inside the building. 
     
     
         28 . The system of  claim 20 , wherein the indirect evaporative cooling unit is located outside the building. 
     
     
         29 . The system of  claim 20 , wherein the heat source for heating the heat transfer fluid in the conditioner and the indirect evaporative cooling unit comprises a gas water heater, a solar module, a solar thermal/photovoltaic module, or a steam loop.