Method and Apparatus for Harvesting Water and Latent Energy from a Gaseous Mixture

Abstract

An apparatus harvests latent energy and water by adiabatically decompressing a controlled volume of atmospheric air to lower its pressure and temperature below the saturation point of included water vapor, thus causing the water vapor to change state to nonvaporous water and release to the decompressed air thermal energy associated with the change of state. The apparatus then extracts the nonvaporous water, leaving the released thermal energy in the decompressed air. The apparatus then recompresses the decompressed air, which will have a resulting temperature, and thus a thermal energy, greater than those of the initially ingested air, and harvests the recompressed air and its increased thermal energy. The apparatus can also humidify and warm atmospheric air before it is ingested to increase appreciably the amount of harvested thermal energy.

1 . A method of operating a mechanically and thermodynamically closed system for harvesting latent energy and water from atmospheric air, one of a desired number of cycles of the method comprising the steps of:
 (a) ingesting a mechanically controlled volume of atmospheric air per unit time into a thermally insulated decompression mechanism;   (b) adiabatically decompressing the controlled volume of atmospheric air to decrease the pressure and temperature of the air to a point where (1) the pressure equals the saturation vapor pressure of the water vapor of the decompressing atmospheric air, (2) the water vapor commences to change state to a nonvaporous water, (3) the adiabatic decompression continues to decrease pressure, temperature and saturation vapor pressure, producing a continuation of water vapor phase change to nonvaporous water, and (4) the water vapor changes of phase continues to release latent energy into the decompressing air;   (c) extracting from the thermally insulated decompression mechanism nonvaporous water that results from the state change and retaining it in a separate, insulated reservoir at the same pressure as that of the decompressed air within the thermally insulated decompression mechanism to render the process of latent energy release nearly irreversible;   (d) adiabatically recompressing, in a thermally insulated recompression mechanism, the previously decompressed air, which now has a much higher temperature, and a greater amount of thermal energy, than had the ingested air before being decompressed; and   (e) extracting the recompressed air from the thermally insulated recompression mechanism, conducting the recompressed air to an external thermal energy harvesting device, and harvesting the greater amount of thermal energy from the recompressed air.   
     
     
         2 . The method as defined by  claim 1 , wherein recompressing the decompressed air during step (d) is terminated when amounts of the pressure and of the volume of the recompressing air are at a state represented at a point along an unsaturated adiabat between a point where the amount of pressure of the recompressing air reaches that of the initial controlled volume of air and a point where the amount of volume of the recompressing air reaches that of the initial controlled volume of air. 
     
     
         3 . The method defined by  claim 1 , wherein:
 in step (b), adiabatically decompressing the controlled volume of atmospheric air further comprises introducing turbulence into the controlled volume of atmospheric air and directing the controlled volume of atmospheric air through a decompression turbine; and   in step (d), adiabatically recompressing the previously decompressed air further comprises directing the decompressed air through a recompression turbine.   
     
     
         4 . A latent energy and water harvesting apparatus, comprising:
 a thermally insulated decompression-recompression mechanism comprising a decompression element and a recompression element, for respectively decreasing the pressure and temperature of atmospheric air within the decompression element and increasing the pressure and temperature of the decompressed air within the recompression element of the thermally insulated decompression-recompression mechanism;   a thermally insulated water reservoir separated from, but in communication with, the decompression element of the thermally insulated decompression-recompression mechanism, for at least temporarily retaining, at the same pressure as the pressure within the decompressing element, nonvaporous water resulting from a state change of water vapor during a decompression of the air within the decompression element; and   an energy harvesting device for harvesting, from recompressed air, thermal energy resulting from the change of state of the water.   
     
     
         5 . The apparatus as defined by  claim 4 , wherein the decompressing-recompressing mechanism comprises:
 a decompression turbine having an air inlet and an air outlet and configured to draw in air at an atmospheric pressure and temperature, decompressing and lowering the temperature of the atmospheric air in the process and causing water vapor present in the atmospheric air to condense;   a reservoir for collecting and isolating the condensed water from the decompressed air;   a recompression turbine having an air inlet and an air outlet and configured to draw in the decompressed air from the decompression turbine, compressing and raising the temperature of the decompressed air in the process;   a conduit extending between the air outlet of the decompression turbine to the air inlet of the recompression turbine to conduct decompressed air from the decompression turbine to the recompression turbine;   a controlled driving device to rotate the decompression and recompression turbines; and   an energy harvesting device for harvesting, from the recompressed air, thermal energy remaining in the recompressed air resulting from the change of state of water from vaporous to nonvaporous.   
     
     
         6 . The apparatus as defined by  claim 4 , wherein the decompression-recompression mechanism comprises:
 a cylinder having a closed end;   a piston slidably disposed within the cylinder, the closed end of the cylinder and the piston defining therebetween a chamber containing air the volume of which is controlled by the position of the piston;   a piston rod connected to the piston; and   a driver for translating the piston rod and piston away from and toward the closed end of the cylinder to decompress and recompress, respectively, air within the chamber.   
     
     
         7 . The apparatus as defined by  claim 4 , wherein the decompression-recompression mechanism comprises:
 a cylinder having a closed end;   a flexible diaphragm disposed at the opposite end from the closed end, the diaphragm and the closed end of the cylinder defining therebetween a chamber containing air, the volume of which is controlled by the position of the diaphragm;   a diaphragm rod connected to the diaphragm; and   a driver for translating the diaphragm rod and diaphragm away from and toward the closed end of the chamber to decompress and recompress, respectively, air within the chamber.   
     
     
         8 . The apparatus as defined by  claim 4 , wherein the decompression-recompression mechanism comprises:
 a cylinder having a closed end;   a cylindrical bellows slidably disposed within the cylinder and having a first end and a second end, the first end being sealingly secured to the closed end of the cylinder;   a pressure plate sealingly secured to the second end of the cylindrical bellows;   a pressure plate rod connected to the second end of the cylindrical bellows; and   a driver for translating the bellows rod and the pressure plate away from and toward the closed end of the cylinder to decompress and recompress, respectively, air within the cylindrical bellows.   
     
     
         9 . The apparatus as defined by  claim 6 , further comprising:
 an external air ingestion device for admitting a controlled volume of atmospheric air containing water vapor into the at least one chamber;   at least one thermally insulated nonvaporous water extracting valve for extracting, from the at least one chamber, the nonvaporous water resulting from the state change of water vapor during decompression;   a nonvaporous water harvesting valve for harvesting nonvaporous water retained in the internal water reservoir;   an external water reservoir to receive and retain nonvaporous water harvested from the internal water reservoir;   at least one thermally insulated air harvesting valve for terminating recompression in, and harvesting recompressed air from, the at least one chamber; and   an apparatus controller for controlling the operation of the air ingestion device, the driver, the at least one nonvaporous water extracting valve, the nonvaporous water harvesting valve, and the at least one air harvesting valve.   
     
     
         10 . The apparatus as defined by  claim 9 , further comprising a pressure sensor for sending signals representative of pressure within the at least one chamber to the apparatus controller. 
     
     
         11 . The apparatus of  claim 9 , wherein the external water reservoir is disposed at an elevation lower than that of the internal water reservoir, and wherein the apparatus further comprises a fluid-turbine-driven electric generator disposed proximate the external water reservoir to harvest energy associated with water flowing, under the influence of gravity, from the internal water reservoir to the external water reservoir. 
     
     
         12 . The apparatus of  claim 9 , wherein the external air ingestion device is an external air ingestion valve, and wherein the apparatus further comprises temperature modifying devices including an air prewarming device, a precooling device and an air prehumidifying device, the external air ingestion valve having the capability of directing air being ingested along one of four routes to the at least one chamber, a first route being directly into the at least one chamber, a second route being through the prewarming or precooling device and then into the at least one chamber, a third route being through the prehumidifying device and then into the at least one chamber, and a fourth route being through both the temperature modifying devices and the prehumidifying device and then into the at least one chamber. 
     
     
         13 . The apparatus of  claim 6 , wherein the piston rod is hollow and the apparatus further comprises:
 a water droplet removal filter comprising a filter holder supporting at least one filter element, the filter being slidably disposed within the at least one chamber to allow relative motion between the filter and air within the at least one chamber to promote the collection and coalescence of water droplets within the at least one chamber upon the filter element; and   a water droplet removal device rod having first and second ends, the first end being connected to the driver and the second end being connected to the filter holder, the water droplet removal device rod coaxially and slidably extending through the hollow piston rod, the driver axially moving the water droplet removal device rod, and thus axially moving the filter holder within the at least one chamber, the motion of the filter holder being independent of the motion of the piston.   
     
     
         14 . The apparatus of  claim 6 , wherein the piston rod is hollow and the apparatus further comprises:
 a water droplet removal fan comprising a fan holder centrally and rotatably supporting a hub about a rotational axis, the fan being slidably disposed within the at least one chamber along the rotational axis;   at least one fan blade radially extending from the hub, the hub being rotatable to revolve the at least one fan blade about the rotational axis of the hub to collect and coalesce water droplets and to create air turbulence that promotes water droplet motion and attending droplet collisions with each other and with the interior surface of the at least one chamber; and   a water droplet removal device rod having first and second ends, the first end being connected to the driver and the second end being connected to the hub, the water droplet removal device rod coaxially, slidably and rotatably extending through the hollow piston rod, the driver axially moving and rotating the water droplet removal device rod, and thus axially moving the fan holder within the at least one chamber and rotating the hub, the motion of the fan holder and of the hub being independent of the motion of the piston.   
     
     
         15 . The apparatus of  claim 14 , wherein the at least one fan blade comprises a radially extending series of blade segments, each blade segment having a pitch that abruptly differs from the pitch of neighboring blade segments, for creating forceful air turbulence within the at least one chamber. 
     
     
         16 . The apparatus of  claim 5 , wherein the energy harvesting device comprises a wind turbine driving an electric generator. 
     
     
         17 . The apparatus of  claim 5 , wherein the energy harvesting device comprises a thermal engine. 
     
     
         18 . The apparatus of  claim 5 , wherein the energy harvesting device comprises a thermoelectric generator for directly producing electric energy proportional to the difference between the temperature of the harvested air and the temperature of the atmospheric air. 
     
     
         19 . The apparatus of  claim 8 , wherein the energy harvesting device comprises a thermal energy reservoir containing a working material that changes state in response to thermal energy transferred to the working material from the harvested air. 
     
     
         20 . A latent energy and water harvesting apparatus, comprising:
 a first, thermally insulated chamber containing a first controllable volume and having a longitudinal axis;   a second, thermally insulated chamber containing a second controlled volume and having a longitudinal axis collinearly disposed with respect to the longitudinal axis of the first chamber;   an external air ingestion valve for ingesting atmospheric air containing water vapor for subsequent admission to the first and second chambers;   a first, thermally insulated, internal air ingestion valve for admitting a controllable volume of ingested atmospheric air into the first chamber;   a decompression-recompression mechanism for increasing the controlled volume within the first chamber to lower the pressure and temperature of the humid air within the first chamber so that included water vapor reaches a point of saturation, commences to change state, and commences to release latent heat, the decompression-recompression mechanism then continuing to lower the pressure and temperature and saturation mixing ratio thereby continuing the change of state of water vapor to nonvaporous water, the decompression-recompression mechanism subsequently decreasing the controlled volume within the first chamber to raise the pressure and temperature of the recompressing air within the first chamber;   a first, thermally insulated, nonvaporous water extracting valve for extracting, from the first chamber, nonvaporous water resulting from the state change of water within the first chamber during decompression to render the process of latent energy release nearly irreversible;   a first thermally insulated water reservoir for temporarily retaining, within the apparatus and at the same pressure as that of the decompressed air in the first chamber, the nonvaporous water extracted from the first chamber;   a first, thermally insulated, air harvesting valve for terminating recompression and harvesting recompressed air from the first chamber;   a second, thermally insulated, internal air ingestion valve for admitting a controllable volume of ingested atmospheric air into the second chamber, the decompression-recompression mechanism increasing the controlled volume within the second chamber to lower the pressure and temperature of the humid air within the second chamber so that included water vapor reaches a point of saturation, commences to change state, and commences to release latent heat, the decompression-recompression mechanism then continuing to lower the pressure and temperature and saturation mixing ratio, thereby continuing the change of state of water vapor to nonvaporous water, the decompression-recompression mechanism subsequently decreasing the controlled volume within the second chamber to raise the pressure and temperature of the recompressing air within the second chamber while the controllable volume within the first chamber is being increased to lower the pressure and temperature of the humid air within the second chamber so that included water vapor reaches a point of saturation, changes state, and releases latent heat;   a second, thermally insulated, nonvaporous water extracting valve for extracting, from the second chamber, nonvaporous water resulting from the state change of water within the second chamber during decompression to render the process of latent energy release nearly irreversible;   a second, thermally insulated water reservoir for temporarily retaining, within the apparatus and at the same pressure as that of the decompressed air in the second chamber, the nonvaporous water extracted from the second chamber;   a second, thermally insulated, air harvesting valve for terminating recompression and harvesting recompressed air from the second chamber;   an energy harvesting device for harvesting thermal energy from air harvested from the first and second chambers;   a first, thermally insulated, nonvaporous water harvesting valve for harvesting water retained in the first water reservoir;   a second, thermally insulated, nonvaporous water harvesting valve for harvesting water retained in the second water reservoir; and   an apparatus controller for controlling the operations of the air ingestion device, the first and second internal air ingestion valves, the decompression-recompression mechanism, the first and second nonvaporous water extracting valves, the first and second air harvesting valves, and the first and second water harvesting valves so that the decompression of the first chamber coincides with the recompression of the second chamber and the recompression of the first chamber coincides with the decompression of the second chamber.   
     
     
         21 . The apparatus of  claim 20 , wherein the first and second chambers comprise a hollow cylinder, closed at each end, within which is slidably disposed a piston that divides the cylinder into the first and second chambers, a controllable volume being defined within each chamber between each closed end and the piston, and wherein the decompression-recompression mechanism comprises the first and second chambers, the piston, a driver and a piston rod connected between the piston and the driver for translating the piston in alternately opposite directions to decompress air within the first chamber while compressing air within the second chamber and then recompressing air within the first chamber while decompressing air within the second chamber.