Method and apparatus for accumulating, storing, and releasing thermal energy and humidity

Abstract

A method and apparatus for supplying heat and humidity to gas filled spaces by the addition of water to a dehydrated material that releases heat upon exposure to water, exposing the hydrated material to dry contacting gas which results in loss of water from the hydrated material to the contacting gas, the contacting gas being heated and humidified by such exposure, and subsequent dispersal of the added heat and humidity to the gas filled space. This sequence also results in regeneration of the dehydrated material so that these steps may be repeated. By limiting the amount of water addition to the dehydrated material within a cycle of the process, less time and/or energy is required to regenerate the dehydrated material and finer control of resultant living space humidity may be possible.

1 . A method of supplying heat to a gas filled space, comprising:
 a) adding a quantity of water to a dehydrated material in solid form that releases heat upon exposure to water, producing a hydrated material,   b) exposing the hydrated material to dry contacting gas, releasing heat and water vapor from the hydrated material to the contacting gas and regenerating the hydrated material back to dehydrated material; and   c) dispersing the heated contacting gas.   
     
     
         2 . The method of  claim 1  further comprising:
 d) when at least a selected percentage of the water added in step (a) has been removed by exposure in step (b), repeating the method from step (a). 
 
     
     
         3 . The method of  claim 2 , in which the selected percentage is 85%. 
     
     
         4 . The method of  claim 2 , further comprising the step, before repeating, of removing any remaining water from the material by exposing the hydrated material to vacuum. 
     
     
         5 . The method of  claim 1  further comprising:
 e) measuring the water vapor in the heated contacting gas from step (b) as the water vapor of the heated contact gas first increases, then reaches a peak value, then declines as the water is removed from the hydrated material; and 
 f) when the water vapor of the heated contacting gas stops declining after it has begun decreasing, repeating the method from step (a). 
 
     
     
         6 . The method of  claim 1 , further comprising the step of removing heat from the hydrated material and dispensing the removed heat to the gas filled space by passing a gas through a conduit in thermal contact with the hydrated material. 
     
     
         7 . The method of  claim 1 , further comprising controlling humidity in the gas filled space by dispersing the heated contacting gas into the gas filled space to raise humidity and dispersing air from a conduit in thermal contact with at least one of the hydrated material or the heated contacting gas to maintain or lower humidity. 
     
     
         8 . The method of  claim 7 , in which the controlling is done by switching between a conduit carrying the heated contacting gas and a bypass conduit carrying gas from a source of gas, in thermal contact with at least one of the hydrated material or the heated contacting gas. 
     
     
         9 . The method of  claim 1 , further comprising the step of condensing at least a portion of the water from the contacting gas and recycling the condensed water as part of the water added in step (a) of  claim 1 . 
     
     
         10 . The method of  claim 1 , in which the material is contained in a chamber, and further comprising the step of contacting at least a thermally conductive portion of the chamber of the material with the source gas prior to step (b) of  claim 1 . 
     
     
         11 . The method of  claim 1 , in which the dry contacting gas is generated from a source gas by heating the source gas. 
     
     
         12 . The method of  claim 1 , further comprising the step of drying the source gas by contacting the source gas with a desiccant, resulting in a dry contacting gas. 
     
     
         13 . The method of  claim 1 , wherein the quantity of water added in step (a) is selected such that a percentage of the water and material mixture that is solid, by volume, is greater than 50% following the water addition. 
     
     
         14 . The method of  claim 1 , wherein the quantity of water added in step (a) is in a range of 5% to 50% of the dehydrated material by weight. 
     
     
         15 . The method of  claim 1 , wherein the quantity of water added in step (a) is in a range of 15% to 35% of the dehydrated material by weight. 
     
     
         16 . The method of  claim 1 , further comprising maintaining the material in step (b) at a temperature no higher than an equilibrium phase transition temperature of the hydrated material throughout the process. 
     
     
         17 . The method of  claim 1 , wherein water is added in step (a) at a rate of greater than 0.1 weight percent of dehydrated material per second. 
     
     
         18 . The method of  claim 1 , wherein water is added in step (a) at a rate of greater than 10 weight percent of dehydrated material per second. 
     
     
         19 . The method of  claim 1  in which the hydrated material comprises one or more materials selected from a group consisting of magnesium sulfate heptahydrate, magnesium sulfate hexahydrate, magnesium sulfate pentahydrate, sodium carbonate decahydrate, sodium carbonate heptahydrate, sodium sulfate decahydrate, sodium tetraborate decahydrate, sodium thiosulfate pentahydrate, sodium thiosulfate dihydrate, copper sulfate pentahydrate, zinc sulfate heptahydrate, zinc sulfate hexahydrate, potassium aluminum sulfate dodecahydrate, trisodium phosphate dodecahydrate, disodium hydrogen phosphate dodecahydrate, disodium hydrogen phosphate heptahydrate, sodium dihydrogen phosphate dihydrate, tri-(sodium metaphosphate) hexahydrate, calcium chloride tetrahydrate, calcium acetate dihydrate and magnesium acetate tetrahydrate. 
     
     
         20 . The method of  claim 1 , in which the hydrated material has an equilibrium phase transition temperature in a range of 30° C. to about 100° C.