Desiccant-based cooling system

Abstract

A desiccant-based system and method for conditioning air includes a first unit remotely located from an area whose environment is to be controlled. Additional units are respectively located within areas where air conditioning is desired. Each of the additional units is connected to the first unit such that desiccant can be transferred between each of the additional units and the first unit. Cool, undiluted desiccant can be transferred from the first unit to at least one of the additional units so that ambient air at the location of the additional unit can be dehumidified and cooled. Each of the additional units are separately controllable, such that the respective environments surrounding the additional units can be maintained at different levels of humidity and temperature.

What is claimed is: 
     
         1 . A system for conditioning air, comprising:
 a first unit housing a regenerator operable to receive a first airflow and bring the first airflow into contact with a liquid desiccant to transfer water from the liquid desiccant to the first airflow, the regenerator including a regenerator sump for collecting the liquid desiccant after water is transferred to the liquid desiccant from the first airflow, the first unit further housing a first portion of a process sump fluidly connected to the regenerator sump; and   a second unit remotely located from the first unit and configured to receive a second airflow and bring the second airflow into contact with the liquid desiccant, the second unit housing a second portion of the process sump for collecting the liquid desiccant after it contacts the second airflow, the first unit being in selective fluid communication with the second unit such that the liquid desiccant can be selectively transferred between the first and second portions of the process sump, and the liquid desiccant transferred from the second portion of the process sump to the first portion of the process sump can be admixed with the liquid desiccant in the regenerator sump prior to the liquid desiccant being returned to the second unit.   
     
     
         2 . The system of  claim 1 , wherein the regenerator sump and the first portion of the process sump are separated by a divider having an aperture disposed therein for facilitating diffusion of the liquid desiccant therebetween. 
     
     
         3 . The system of  claim 1 , wherein the first unit is located outside a building and is configured to receive and exhaust the first airflow from and to an ambient outdoor environment, and the second unit is located inside the building and is configured to receive and exhaust the second airflow from and to an ambient environment inside the building. 
     
     
         4 . The system of  claim 1 , wherein the first and second units are operable in a first mode of operation to transfer water from the second airflow to the liquid desiccant, and in a second mode of operation to transfer water from the liquid desiccant to the second airflow, when the second airflow is brought into contact with the liquid desiccant in the second unit. 
     
     
         5 . The system of  claim 4 , wherein the regenerator is configured to be shut down during the second mode of operation to inhibit evaporation of water from the liquid desiccant in the regenerator sump. 
     
     
         6 . The system of  claim 4 , wherein the first unit further houses at least a portion of a refrigeration system configured to selectively heat and cool the liquid desiccant through heat transfer with a refrigerant. 
     
     
         7 . The system of  claim 6 , wherein the first unit houses at least an evaporator of the refrigeration system, and includes a first process pump configured to pump the liquid desiccant from the first portion of the process sump through the evaporator during the first mode of operation to transfer heat from the liquid desiccant to the refrigerant prior to the liquid desiccant being transferred to the second unit and brought into contact with the second airflow. 
     
     
         8 . The system of  claim 7 , further comprising a bypass valve configured to return a portion of the liquid desiccant leaving the evaporator to the first portion of the process sump prior to the liquid desiccant being transferred to the second unit. 
     
     
         9 . The system of  claim 6 , wherein the first unit includes a regenerator pump configured to pump the liquid desiccant from the regenerator sump through a condenser of the refrigeration system during the first mode of operation to receive heat from the refrigerant prior to being brought into contact with the first airflow. 
     
     
         10 . The system of claim of  claim 9 , wherein the refrigeration system further includes a second condenser configured to further cool the refrigerant prior to an expansion phase of the refrigerant. 
     
     
         11 . A system for conditioning air, comprising:
 a first unit remotely located from an indoor space; and   a second unit located within the indoor space and in selective fluid communication with the first unit,   the first unit including a regeneration chamber into which a first airflow is introduced and contacted with a liquid desiccant to transfer water from the liquid desiccant to the first airflow, the regeneration chamber including a regenerator sump for collecting the liquid desiccant after water is transferred to the liquid desiccant from the first airflow,   the first unit further including a first process chamber separated from the regenerator chamber such that the first airflow is inhibited from entering the first process chamber, the first process chamber including a first portion of a process sump fluidly connected to the regenerator sump,   the second unit including a second process chamber into which a second airflow is introduced and contacted with the liquid desiccant to transfer water between the second airflow and the liquid desiccant prior to the second airflow being discharged into the indoor space, the second process chamber including a second portion of the process sump for collecting the liquid desiccant after it contacts the second airflow, the selective fluid communication between the first and second units providing selective transfer of the liquid desiccant between the first and second portions of the process sump.   
     
     
         12 . The system of  claim 11 , further comprising a plurality of the second units, each located within a respective indoor space and each in selective fluid communication with the first unit. 
     
     
         13 . The system of  claim 11 , wherein the regenerator chamber and the first process chamber are separated by a divider having an aperture disposed between the regenerator sump and the first portion of the process sump for facilitating diffusion of the liquid desiccant therebetween. 
     
     
         14 . The system of  claim 11 , wherein the first and second units are operable in a first mode of operation to transfer water from the second airflow to the liquid desiccant, and in a second mode of operation to transfer water from the liquid desiccant to the second airflow, when the second airflow is brought into contact with the liquid desiccant in the second unit. 
     
     
         15 . The system of  claim 14 , wherein the first unit further houses at least a portion of a refrigeration system configured to selectively heat and cool the liquid desiccant through heat transfer with a refrigerant. 
     
     
         16 . The system of  claim 15 , wherein the first unit houses at least an evaporator of the refrigeration system, the first process chamber including a first process pump configured to pump the liquid desiccant from the first portion of the process sump through the evaporator during the first mode of operation to transfer heat from the liquid desiccant to the refrigerant prior to the liquid desiccant being transferred to the second unit and brought into contact with the second airflow. 
     
     
         17 . The system of  claim 16 , further comprising a bypass valve configured to return a portion of the liquid desiccant leaving the evaporator to the first portion of the process sump prior to the liquid desiccant being transferred to the second unit, thereby allowing the first portion of the process sump to retain the cooled desiccant. 
     
     
         18 . The system of  claim 17 , wherein the regeneration chamber includes a regenerator pump configured to pump the liquid desiccant from the regenerator sump through a condenser of the refrigeration system during the first mode of operation to receive heat from the refrigerant prior to being brought into contact with the first airflow. 
     
     
         19 . A method for conditioning air, comprising:
 bringing a first airflow into contact with a liquid desiccant in a regeneration chamber to transfer water from the liquid desiccant to the first airflow during a first mode of operation;   collecting the liquid desiccant in a regenerator sump after water is transferred from the liquid desiccant to the first airflow;   admixing the liquid desiccant in the regenerator sump with liquid desiccant in a first portion of a process sump disposed in a first process chamber adjacent the regeneration chamber;   transferring some of the liquid desiccant from the first portion of the process sump to a second portion of the process sump disposed in a second process chamber located remotely from the first process chamber;   bringing a second airflow into contact with the liquid desiccant in the second process chamber to transfer water from the second airflow to the liquid desiccant during the first mode of operation; and   exhausting the second airflow from the second process chamber into an ambient environment having air to be conditioned, after the second airflow has contacted the liquid in the second process chamber.   
     
     
         20 . The method of  claim 19 , further comprising inhibiting the first airflow from contacting the liquid desiccant in the regeneration chamber during a second mode of operation; and bringing a second airflow into contact with the liquid desiccant in the second process chamber to transfer water from the liquid desiccant to the second airflow during the second mode of operation.