The present invention relates generally to systems for recovering water from combustion exhaust gas, and more particularly, to systems and methods for recovering water from combustion exhaust gases in a diffusion absorption refrigeration cycle.
Military operations typically involve transporting a large number of troops over large distances often in harsh or unfriendly areas. The logistics train to supply the Forward Operating Bases (“FOBs”) can be very expensive in terms of dollars, strategic vulnerability, and lives lost as demonstrated by recent wars in Afghanistan and Iraq. Bulk materials requiring ground transport may have to be moved long distances over poor road systems that may also be under continued assault by enemy forces. Two important bulk quantities that must be moved are fuel and water. The burden in moving both materials can be great.
Water is a particular need that is difficult to meet for troops in the field. Water is not only used for drinking. It is needed for cooking, cleaning, and sanitation systems. A budget of 6-8 gallons of water a day per soldier is typically used in determining logistics. The water is usually delivered by convoy or helicopter at a high cost. The delivery of the water also places additional troops in harms way. Efforts have been made to capture the water lost to the atmosphere by combustion engines, such as engines used to drive power generators or vehicles in the field. Regrettably, for every gallon of fuel burned, a gallon of water is produced, but this water is released with the exhaust into the atmosphere as superheated vapor and lost. Present systems typically involve cooling the water using vapor compression or some other refrigeration methods. Such methods typically require energy, such as electricity or fuel for power. Diffusion Absorption Refrigeration systems have been used to provide the cooling mechanism. However, fuel such as propane, electricity or some other way of generating heat is required as fuel.
in view of the foregoing, there is an ongoing need for a system and method for cooling exhaust gas from combustion engines that require no additional fuel and that are capable of extracting clean potable water from combustion exhaust gases.
Military operations typically involve transporting a large number of troops over large distances often in harsh or unfriendly areas. The logistics train to supply the Forward Operating Bases (“FOBs”) can be very expensive in terms of dollars, strategic vulnerability, and lives lost as demonstrated by recent wars in Afghanistan and Iraq. Bulk materials requiring ground transport may have to be moved long distances over poor road systems that may also be under continued assault by enemy forces. Two important bulk quantities that must be moved are fuel and water. The burden in moving both materials can be great.
Water is a particular need that is difficult to meet for troops in the field. Water is not only used for drinking. It is needed for cooking, cleaning, and sanitation systems. A budget of 6-8 gallons of water a day per soldier is typically used in determining logistics. The water is usually delivered by convoy or helicopter at a high cost. The delivery of the water also places additional troops in harms way. Efforts have been made to capture the water lost to the atmosphere by combustion engines, such as engines used to drive power generators or vehicles in the field. Regrettably, for every gallon of fuel burned, a gallon of water is produced, but this water is released with the exhaust into the atmosphere as superheated vapor and lost. Present systems typically involve cooling the water using vapor compression or some other refrigeration methods. Such methods typically require energy, such as electricity or fuel for power. Diffusion Absorption Refrigeration systems have been used to provide the cooling mechanism. However, fuel such as propane, electricity or some other way of generating heat is required as fuel.
In view of the foregoing, there is an ongoing need for a system and method for cooling exhaust gas from combustion engines that require no additional fuel and that are capable of extracting clean potable water from combustion exhaust gases.
In view of the above, an exhaust gas water extraction system is provided, in an example implementation, an exhaust gas water extraction system includes an evaporator component in a diffusion absorption refrigeration (“DAR”) unit. The system also includes an exhaust gas input duct comprising an input opening to receive exhaust gas from an exhaust gas source. The exhaust gas input duct operates as a heat source to power the DAR. An evaporator heat exchanger is connected to receive the exhaust gas from the exhaust gas input duct. The evaporator heat exchanger is disposed to generate a heat exchange between the evaporator component and the exhaust gas that cools the exhaust gas to below the dew point. A water collection container receives water condensing from the exhaust gas during the heat exchange with the evaporator component.
In an example alternative implementation, the exhaust gas water extraction system further includes an ambient air opening to an evaporator-ambient air heat exchanger to condense water from the ambient air. The water from the ambient air is collected with the condensate from exhaust gas.
In another example alternative implementation, a water purification system may be added to the purify the water collected from the condensation of the water vapor in the exhaust gas.
In another example, a modular exhaust gas water extraction system takes advantage of the integrated heat exchange opportunities in providing fluid pathways for exhaust gases, ambient air, and refrigerant or refrigerant/absorbent binary solutions within a standard size for multiplying modules and for easy transport by standard size carriers already use.
Other devices, apparatus, systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, he within the scope of the invention, and be protected by the accompanying claims.
The invention can be better understood by referring to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention, in the figures, reference numerals designate corresponding parts throughout the different views.
The generator 104 drives a DAR cycle using the heat supplied by the hot exhaust gas in a manner known in the art. The storage tank 108 stores hot refrigerant from the boiler 104 and a refrigerant/absorbent solution, which is provided to an absorber 114. The hot refrigerant is provided to a condenser 110, which discharges heat Qcond at 120 as the refrigerant cools. The cooling refrigerant is provided to an evaporator 112 to supply refrigerant that is absorbed by the refrigerant/absorbent solution in the absorber 114 thereby providing the well-known cooling of the refrigerant in the evaporator 112.
The hot exhaust gas is conducted along an exhaust gas fluid path 150 to an evaporator heat exchanger 152. The evaporator heat exchanger 152 provides a cooling of the exhaust gas illustrated by the heat transfer Qev at 130 into the evaporator 112. The heat transfer Qev at 130 cools the exhaust gas to below the dew point causing a condensation of water vapor contained in the exhaust gas. The water condensate is extracted by gravity and collected in a water collection container 140.
The generator 204 drives a DAR cycle using the heat supplied by the hot exhaust gas as described above with reference to
The hot exhaust gas is conducted along an exhaust gas fluid path 250 through a recuperator heat exchanger 240 configured to receive the hot exhaust gas before the exhaust gas is cooled by the evaporator 212. The recuperator heat exchanger 240 also receives cooled exhaust gas to provide a counter-flow heat exchange between the hot exhaust gas and the cooled exhaust gas.
The now pre-cooled exhaust gas is conducted along the exhaust gas fluid path 250 to an evaporator heat exchanger 252. The exhaust gas is conducted along the exhaust gas fluid path 250 through an intercooler 220 disposed between the exhaust gas input duct 202 and the evaporator heat exchanger 252. The intercooler 220 in
The evaporator heat exchanger 252 provides a cooling of the exhaust gas illustrated by the heat transfer Qev at 230 into the evaporator 212. The heat transfer Qev at 230 cools the exhaust gas to below the dew point causing a condensation of water vapor contained in the exhaust gas. The water condensate is extracted by gravity and collected in a water collection container 258. Cooled exhaust gas, or low-thermal signature exhaust, from which water has been extracted may be conducted to the recuperator heat exchanger 240 to pre-cool the hot exhaust gas received from the exhaust gas input duct 202.
Condensate water collected in the water collection container 258 may be conducted to a water purification system 270 comprising a water filtering component configured to extract impurities from the water received from the water collection container 258. The water purification system 270 may include a pump to direct the water from the water collection container to the water filtering component. Alternatively to a pump, the pressure differential required to operate the filters can be provided by the exhaust gases, or by a turbo-pump driven by the exhaust gases. The water filtering component may include filters selected from a group consisting of a particulate filter, a hydrocarbon filter, an activated carbon filter, and any combination thereof. The hydrocarbon filter may include hydrocarbon filtering material selected from a group consisting of a smartsponge, organoclay, poly-pro, and any combination thereof.
The system 200 in
The generator 304 drives the DAR cycle as describe above with reference to
The hot exhaust gas enters the intercooler 332 for pre-cooling through a counter-flow heat exchange with cooled dry ambient air. The pre-cooled exhaust gas flows along an exhaust gas flow path 350 to an evaporator heat exchanger, which may be implemented by including a first plurality of evaporator HEX fins 352. The evaporator FLEX fins 352 may be cooled by thermal contact with the evaporator gas cooling portion 312b to below the dew point. The condensate water extracted by cooling by the evaporator HEX fins 352 is collected at an exhaust gas water collection container 358. The cooled dry exhaust gas passed the evaporator HEX fins 352 flows along path 350 to a cooled gas output after thermal exchange with the inlet hot exhaust gas at 302.
The system 300 in
The system 400 in
The system 400 in
The multi-section heat exchanger 402 includes an evaporator heat exchanger section and an intercooler section 418. The evaporator heat exchanger section is formed by an evaporator to gas heat exchanger portion 412 and an evaporator to air heat exchanger portion 413. The evaporator heat exchanger section is defined by an area of the first and second HEX panels cooled by an evaporator-component (see
The intercooler heat exchanger section 418 provides the mechanism for heat exchange between the cooled air flowing over the HEX panels 404a and 404b and the hot exhaust gas coming up from the exhaust gas outlet 410 on the exhaust gas input duct 406. The intercooler section 418 pre-cools the hot exhaust gas as it flows inside the HEX enclosure towards the evaporator heat exchanger section.
The absorber component 414 in
The system 400 in
The exhaust gas input section 405, which includes the exhaust gas duct 406, includes a generator 420 configured to drive the DAR cycle. The generator 420 is in thermal connection to a liquid-to-gas heat exchanger to receive heat from the hot exhaust gas in the exhaust gas duct 406 to drive the DAR cycle. The generator 420 may be implemented as shown in
A water collection channel 426 extends along the length of the multi-section heat exchanger 402 to receive water condensing from the exhaust gas and ambient air being cooled by the multi-section heat exchanger 402.
Figures SA and 5B are top cross-sectional views of example implementations of multi-section heat exchangers 500 and 550 illustrating the use of tins to enhance heat exchange.
As shown in
As shown in
The system in
Hot exhaust gas enters the system 800 at an input opening of an exhaust gas input duct 801. The exhaust gas input duct 801 may pass a liquid to gas heat exchanger to provide thermal contact with a generator as described above with reference to
The system 800 also includes a gas-to-air HEX section 815 along a second side of the multi-section heat exchanger 802 opposite the first side. The gas-to-air HEX section 815 includes a cooled gas duct connected to a cooled exhaust gas opening to the HEX enclosure 804. The cooled gas duct connects to the cooled exhaust gas opening and extends to an opening 810 in a top side of the gas-to-air HEX section 815.
Other devices, apparatus, systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
This application claims priority to provisional patent application U.S. App. Ser. No. 61/688,546 titled “Water Recovery from Combustion Exhaust,” by Wade Pulliam, Augustus Moore, Conor C. Galligan, Merritt J. Jenkins, and Eric. S. Packer, filed on May 17, 2012, which is incorporated herein by reference. This application also claims priority to provisional patent application U.S. App. Ser. No. 61/752,715 titled “Water from Exhaust Vapor and Ambient Air,” by Claudio Fillipone, filed on Jan. 13, 2013, which is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/US2013/041261 | 5/15/2013 | WO | 00 |
Number | Date | Country | |
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61688546 | May 2012 | US | |
61752715 | Jan 2013 | US |