Thermochemical Material Systems for Heating Ventilation and Air Conditioning

Abstract

A thermal energy storage (TES) system using a thermochemical material (TCM) may have a discharging mode (i.e., heat releasing mode) and a charging mode (i.e., heat absorbing mode), both of which can be used in building heating, ventilation, and air conditioning (HVAC) applications. During both modes, the water vapor/moisture contained in the air interacts with the TCM. During discharging, water vapor is absorbed by the TCM and the heat of reaction is released to the air, resulting in a substantially dehumidified air which may be slightly heated and can be used for heating applications. During charging, the TCM may be heated to drive the reversible dehydration reaction and release the moisture to the air, preparing it for cooling applications.

What is claimed is: 
     
         1 . A method comprising:
 contacting a thermochemical material (TCM) with a first air stream resulting in a dehumidified and heated first air stream;   directing the dehumidified and heated first air stream to interact with a second air stream; and   releasing a heated second air stream into an indoor space; wherein:   the first air stream enters the TCM from the indoor space, and   the directing causes the second air stream to be heated resulting in the heated second air stream.   
     
     
         2 . The method of  claim 1 , wherein:
 the contacting comprises:
 receiving the first air stream; and 
 removing a humidity from the first air stream resulting in the dehumidified and heated first air stream; wherein: 
   the removing results in the humidity being absorbed by the TCM, and   the contacting is performed in a TCM bed.   
     
     
         3 . The method of  claim 1 , wherein:
 the directing comprises:
 receiving the dehumidified and heated first air stream and the second air stream; and 
 transferring a heat from the dehumidified and heated first air stream to the second air stream; wherein: 
   the transferring results in the dehumidified and heated first air stream becoming an exhausted first air stream, and   the transferring results in the second air stream becoming the heated second air stream.   
     
     
         4 . The method of  claim 3 , wherein:
 the directing is performed in a heat exchanger.   
     
     
         5 . The method of  claim 4 , wherein:
 the second air stream enters the heat exchanger from an external ambient.   
     
     
         6 . The method of  claim 1 , wherein:
 the TCM comprises a salt hydrate.   
     
     
         7 . The method of claim  8 , wherein:
 the salt hydrate comprises at least one of magnesium chloride (MgCl 2 ), strontium bromide (SrBr 2 ), calcium hydroxide (Ca(OH) 2 ), potassium carbonate (K 2 CO 3 ), lithium hydroxide (LiOH), or strontium chloride (SrCl 2 ).   
     
     
         8 . A system comprising:
 a thermochemical material (TCM) bed configured to receive a first air stream and to release a heated and dehumidified first air stream; and   a heat exchanger comprising:
 a first inlet configured to receive the heated and dehumidified first air stream; 
 a second inlet configured to receive a second air stream; 
 a first outlet configured to release a heated second air stream into an indoor space; and 
 a second outlet configured to release an exhausted first air stream; wherein: 
   the TCM bed comprises a TCM,   the TCM bed is configured to absorb a humidity from the first air stream resulting in the dehumidified and heated first air stream being released from the TCM bed,   the heat exchanger is configured to transfer heat from the dehumidified and heated air stream to the second air stream, resulting in the heated second air stream being released via the first outlet and the exhausted first air stream being released via the second outlet.   
     
     
         9 . The system of  claim 8 , wherein:
 the TCM comprises a salt hydrate.   
     
     
         10 . The system of  claim 9 , wherein:
 the salt hydrate comprises at least one of magnesium chloride (MgCl 2 ), strontium bromide (SrBr 2 ), calcium hydroxide (Ca(OH) 2 ), potassium carbonate (K 2 CO 3 ), lithium hydroxide (LiOH), or strontium chloride (SrCl 2 ).   
     
     
         11 . The system of  claim 8 , wherein:
 the second inlet and the second outlet are substantially co-located.   
     
     
         12 . A method comprising:
 contacting a mixed air stream with a sorbent material in a first channel;   directing a first portion of the mixed air stream to interact with the sorbent material in a second channel; and   releasing a second portion of the mixed air stream into an indoor space;   wherein:   the directing results in a humidity from the second portion of the mixed air stream to the sorbent material.   
     
     
         13 . The method of  claim 12 , further comprising:
 combining a first air stream and a second air stream to form a mixed air stream; wherein:   the combining occurs prior to the contacting.   
     
     
         14 . The method of  claim 13 , wherein:
 the first air stream is sourced from the indoor space.   
     
     
         15 . The method of  claim 13 , wherein:
 the second air stream is sourced from an external ambient.   
     
     
         16 . The method of  claim 12 , wherein:
 the contacting comprises:
 receiving a first air stream and a second air stream into the first channel; and 
 placing a sorbent in thermodynamic communication with the mixed air stream; wherein: 
   the mixed air stream comprises the first air stream and the second air stream.   
     
     
         17 . The method of  claim 12 , wherein:
 the contacting further comprises contacting the mixed air stream with a water film in the first channel.   
     
     
         18 . The method of  claim 12 , wherein:
 the directing comprising:
 receiving the first portion of the mixed air stream into the second channel, 
 contacting the sorbent material with the first portion of the mixed air stream in the second channel resulting in an exhausted mixed air stream; and 
 releasing the exhausted mixed air stream to an external ambient. 
   
     
     
         19 . The method of  claim 12 , wherein:
 the first channel and the second channel are separated by a plate.   
     
     
         20 . The method of  claim 19 , wherein:
 the plate is substantially permeable by heat and water.