Desiccant air conditioning system using refrigerant

Abstract

A liquid desiccant air conditioning system (LDAC). The LDAC has a plurality of modules including at least an initial module and a terminal module that may include one or more intermediate modules. The liquid desiccant is passed through each module and contacts an airstream in each module and subsequently collected in a basin. The liquid desiccant is supplied to a common heat exchanger where thermal energy is exchanged between the liquid desiccant and a refrigerant. The liquid desiccant is supplied from the common heat exchanger to a desiccant distributor for each of the plurality of modules such that the concentration and temperature of the liquid desiccant is essentially the same at each desiccant distributor.

What is claimed is: 
     
         1 . A liquid desiccant air conditioning system (LDAC) comprising,
 an initial module, comprising at least a housing with a media pad and a desiccant distributor configured to disburse liquid desiccant from the desiccant distributor to the media pad;   a terminal module in fluid communication with the initial module, the terminal module comprising at least a housing with a media pad and a desiccant distributor configured to disburse liquid desiccant from the desiccant distributor to the media pad;   at least a first basin in fluid communication with at least one of the initial module or the terminal module to receive liquid desiccant from the media pad;   an air intake in fluid communication with the initial module to receive untreated air and direct the untreated air to the initial module;   an air exhaust in fluid communication with the terminal module to exhaust treated air from the LDAC;   a common heat exchanger in fluid communication with at least the first basin and each of the desiccant distributors, wherein the common heat exchanger is in fluid communication with a refrigerant that is operationally coupled to the liquid desiccant to exchange thermal energy between the refrigerant and the liquid desiccant.   
     
     
         2 . The LDAC of  claim 1  comprising at least one liquid desiccant pump in fluid communication with at least the first basin and a liquid desiccant input of the common heat exchanger. 
     
     
         3 . The LDAC of  claim 1 , wherein the first basin is a common return header for at least the initial module and the terminal module. 
     
     
         4 . The LDAC of  claim 1  comprising at least one intermediate module comprising at least a housing with a media pad and a desiccant distributor configured to disburse liquid desiccant from the desiccant distributor to the media pad. 
     
     
         5 . The LDAC of  claim 4 , wherein the at least one intermediate module includes a media pad that is in fluid communication with the common return header. 
     
     
         6 . The LDAC of  claim 1  comprising at least a second basin, wherein the first basin is associated with the initial module and the second basin is associated with the terminal module wherein the first and second basin are in fluid communication with the common heat exchanger. 
     
     
         7 . The LDAC of  claim 6  wherein the first basin and second basin are in fluid communication such that the first basin is downstream of the second basin and the second basin is upstream of the first basin and downstream of the common heat exchanger. 
     
     
         8 . The LDAC of  claim 1  comprising a common supply header in fluid communication with a liquid desiccant output of the common heat exchanger and each desiccant distributor. 
     
     
         9 . The LDAC of  claim 8 , comprising a three way valve in fluid communication with the common heat exchanger and each desiccant distributor and at least the first basin to distribute liquid desiccant from the common heat exchanger to each desiccant distributor and the first basin. 
     
     
         10 . A method of using liquid desiccant to condition an air stream, comprising:
 moving an air stream through a liquid desiccant air conditioning system (LDAC) from an air intake through at least an initial module and a terminal module to an air exhaust such that the air stream contacts a media pad in each of the initial module and terminal module;   causing a liquid desiccant to flow from a desiccant distributor through the media pad in each of the initial module and terminal module wherein the liquid desiccant contacts the air stream;   collecting the liquid desiccant in a basin;   pumping the liquid desiccant from the basin to a liquid desiccant input of a common heat exchanger;   exchanging thermal energy between the liquid desiccant and a refrigerant in the common heat exchanger; and   supplying liquid desiccant from the liquid desiccant output of the common heat exchanger to the desiccant distributor of each of the initial module and the terminal module.   
     
     
         11 . The method of  claim 10  wherein the liquid desiccant from the common heat exchanger is substantially the same temperature and concentration at the desiccant distributor for both the initial module and the terminal module. 
     
     
         12 . The method of  claim 10  wherein collecting the liquid desiccant in the basin comprises using a common return header to the common heat exchanger. 
     
     
         13 . The method of  claim 10  wherein exchanging thermal energy comprises using a compressor refrigerant system. 
     
     
         14 . The method of  claim 10  comprising moving the air stream through at least one intermediate module, causing liquid desiccant to flow from a desiccant distributor through the media pad of the at least one intermediate module, and supplying liquid desiccant from the output of the common heat exchanger to the desiccant distributor of the at least one intermediate module. 
     
     
         15 . The method of  claim 10  wherein supplying liquid desiccant from the common heat exchanger comprises supplying a portion of the liquid desiccant to the desiccant distributor or each of the initial module, the at least one intermediate module, and the terminal module and a portion of the liquid desiccant to the first basin. 
     
     
         16 . A liquid desiccant air conditioning system (LDAC) comprising,
 a refrigerator portion, the refrigeration portion comprising:
 an initial module, comprising at least a housing with a media pad; 
 a terminal module in fluid communication with the initial module, the terminal module comprising at least a housing with a media pad; 
 a desiccant distributor configured to disburse liquid desiccant from the desiccant distributor to the media pad of the initial module and the terminal module; and 
 a basin in fluid communication with at least one of the initial module or the terminal module to receive liquid desiccant from the media pad; 
   a concentrator portion, the concentrator portion comprising:
 an initial module, comprising at least a housing with a media pad; 
 a terminal module in fluid communication with the initial module, the terminal module comprising at least a housing with a media pad; 
 a desiccant distributor configured to disburse liquid desiccant from the desiccant distributor to the media pad of the initial module and the terminal module; and 
 a basin in fluid communication with at least one of the initial module or the terminal module to receive liquid desiccant from the media pad; 
   a condenser/evaporator heat exchanger in fluid communication with the refrigerator portion and the concentrator portion, the common condenser/evaporator heat exchanger comprising:
 a cold common heat exchanger in fluid communication with the basin of the concentrator to receive concentrated liquid desiccant and output cold liquid desiccant to the refrigerator portion; 
 a hot common heat exchanger in fluid communication with the basin of the refrigerator portion to receive diluted liquid desiccant and output hot liquid desiccant to the concentrator portion; 
   an air intake in fluid communication with the initial module to receive untreated air and direct the untreated air to the initial module; and   an air exhaust in fluid communication with the terminal module to exhaust treated air from the LDAC.   
     
     
         17 . The LDAC of  claim 16  comprising a three way valve in fluid communication with the output of the cold common heat exchanger to direct a portion of the cold liquid desiccant to the desiccant distributor and a portion of the cold liquid desiccant to the basin. 
     
     
         18 . The LDAC of  claim 16  comprising a three way valve in fluid communication with the output of the hot common heat exchanger to direct a portion of the hot liquid desiccant to the desiccant distributor and a portion of the hot liquid desiccant to the basin. 
     
     
         19 . The LDAC of  claim 17  comprising another three way valve in fluid communication with the output of the hot common heat exchanger to direct a portion of the hot liquid desiccant to the desiccant distributor and a portion of the hot liquid desiccant to the basin. 
     
     
         20 . The LDAC of  claim 16  wherein at least one of the refrigerator portion or the concentrator portion comprises an intermediate module.