Absorption vacuum dehumidification system and method using the same

Abstract

An absorption vacuum dehumidification system includes a vacuum section, an absorber, a desorber, a photovoltaic energy supply, a heat exchanger, a condenser, and a desiccant solution. The vacuum section has a feed side and a permeate side and comprising a hydrophilic membrane that separates the feed side than the permeate side. The absorber is connected to the permeate side of the vacuum section. The desorber is connected to the absorber to form a desiccant solution cycle path between the absorber and the desorber. The photovoltaic energy supply configured to power a heat source that provides hot liquid into the desorber. The heat exchanger is connected to the desiccant solution cycle path. The condenser is connected to the desorber. The desiccant solution flows along the desiccant solution cycle path.

1 . An absorption vacuum dehumidification system, comprising:
 a vacuum section;   an absorber connected to a permeate side of the vacuum section, wherein cooling water is input in and output from the absorber;   a desorber, wherein hot water is input in and output from the desorber;   a heat exchanger connected between the absorber and the desorber; and   a condenser, wherein cooling water is input in and output from the condenser,   wherein a weak desiccant solution is pumped to the desorber and is heated up at the desorber,   wherein first water vapor is desorbed from the weak desiccant solution and is transferred to the condenser,   wherein the transferred first water vapor is cooled down to become liquid water at the condenser,   wherein a strong desiccant solution leaving the desorber is pre-cooled at the heat exchanger before entering the absorber, and the strong desiccant solution is diluted by absorbing second water vapor which is extracted from a moist air stream entering a feed side of the vacuum section through the hydrophilic membrane, and a dehumidified air stream is outputted from the vacuum section.   
     
     
         2 . The absorption vacuum dehumidification system of  claim 1 , further comprising:
 a desiccant pump disposed between the absorber and the heat exchanger; and   an expansion valve disposed between the absorber and the heat exchanger,   wherein the weak desiccant solution is pumped to the desorber by the desiccant pump,   wherein the strong desiccant solution pre-cooled by the heat exchanger is throttled by the expansion valve and fed into the absorber.   
     
     
         3 . The absorption vacuum dehumidification system of  claim 1 , wherein the cooling water input in and output from the absorber is configured to facilitate absorption of the second water vapor inside the absorber into the strong desiccant solution and to dilute the strong desiccant solution, wherein the absorption of second water vapor makes the absorber maintained at a low pressure. 
     
     
         4 . The absorption vacuum dehumidification system of  claim 1 , wherein
 pressure inside the condenser is equal to pressure inside the desorber, and   pressure inside the absorber is equal to pressure inside the permeate side of the vacuum section.   
     
     
         5 . The absorption vacuum dehumidification system of  claim 1 , wherein at least one of the weak desiccant solution and the strong desiccant solution comprises lithium bromide. 
     
     
         6 . A method for absorption vacuum dehumidification, comprising:
 pumping a weak desiccant solution to a desorber, wherein the weak desiccant solution is heated up at the desorber by hot water input into the desorber such that first water vapor is desorbed from the weak desiccant solution and is then transferred to a condenser;   inputting cooling water to the condenser, such that the transferred first water vapor is cooled down to become liquid water at the condenser;   transferring a strong desiccant solution from the desorber to an absorber, wherein a heat exchanger is instructed to pre-cool the strong desiccant solution before the strong desiccant solution enters the absorber; and   extracting second water vapor from a moist air stream which enters a feed side of a vacuum section through a hydrophilic membrane, so as to output a dehumidified air stream from the vacuum section, wherein the strong desiccant solution is diluted by absorbing the second water vapor inside the absorber.   
     
     
         7 . The method of  claim 6 , further comprising:
 pumping the weak desiccant solution to the desorber by a desiccant pump; and   throttling the strong desiccant solution flowing from the heat exchanger by the expansion valve and then feeding the strong desiccant solution into the absorber.   
     
     
         8 . The method of  claim 6 , wherein the absorber is with cooling water in and out so as to facilitate the absorption of the second water vapor into the strong desiccant solution and the dilution of the strong desiccant solution, wherein the absorption of water vapor makes the absorber maintained at a low pressure. 
     
     
         9 . The method of  claim 6 , wherein
 pressure inside the condenser is equal to pressure inside the desorber, and   pressure inside the absorber is equal to pressure inside a space of the permeate side of the vacuum section.   
     
     
         10 . The method of  claim 6 , wherein at least one of the weak desiccant solution and the strong desiccant solution comprises lithium bromide. 
     
     
         11 . An absorption vacuum dehumidification system, comprising:
 a vacuum section having a feed side and a permeate side and comprising a hydrophilic membrane that separates the feed side than the permeate side;   an absorber connected to the permeate side of the vacuum section;   a desorber connected to the absorber to form a desiccant solution cycle path between the absorber and the desorber;   a photovoltaic energy supply configured to power a heat source that provides hot liquid into the desorber;   a heat exchanger connected to the desiccant solution cycle path;   a condenser connected to the desorber; and   a desiccant solution flowing along the desiccant solution cycle path.   
     
     
         12 . The absorption vacuum dehumidification system of  claim 11 , further comprising:
 a desiccant pump in communication with the desiccant solution cycle path and configured to pump the desiccant solution from the absorber to the desorber; and   an expansion valve in communication with the desiccant solution cycle path and configured to throttle the desiccant solution from the desorber to the absorber.   
     
     
         13 . The absorption vacuum dehumidification system of  claim 11 , further comprising:
 a vapor tube connecting the vacuum section to the absorber such that the hydrophilic membrane is physically free from the desiccant solution cycle path at least by the vapor tube.   
     
     
         14 . The absorption vacuum dehumidification system of  claim 13 , wherein the feed side is physically separated from the desiccant solution cycle path at least by the vapor tube and the permeate side. 
     
     
         15 . The absorption vacuum dehumidification system of  claim 14 , wherein the feed side of the vacuum section is configured to provide a flowing path to allow moist air entering to flow through the feed side without involving with the desiccant solution cycle path.