Water removal system having a transport membrane evaporator system and a refrigeration system

Abstract

A water removal system includes a transport membrane evaporator, a first condenser and a water pump all in fluid communication with each other and which operate to circulate refrigerant water acting as a first refrigerant therethrough. The transport membrane evaporator includes a first flow path and a second flow path. The first flow path is operable to flow the refrigerant water therethrough under a vacuum pressure that is low enough to vaporize the refrigerant water within the first flow path. The second flow path is operable to flow a fluid having water therethrough. Both water and heat are transferred from the fluid in the second flow path to the refrigerant water in the first flow path through a membrane-based material of the transport membrane evaporator, such that the fluid passing through the second flow path has at least a portion of its water removed and is cooled.

Description

WATER REMOVAL SYSTEM HAVING A TRANSPORT MEMBRANE EVAPORATORSYSTEM AND A REFRIGERATION SYSTEMCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a non-provisional application of, and claims the benefit of the filing date of, U.S. provisional application 63 / 579,360 , filed August 29, 2023, entitled: “WATER REMOVAL SYSTEM HAVING A TRANSPORT MEMBRANE EVAPORATOR SYSTEM AND A REFRIGERATION SYSTEM,” the contents of which are incorporated herein by reference in their entirety.TECHNICAL FIELD

[0002] The present disclosure relates to water removal systems and methods of using the same. More specifically, the disclosure relates to water removal systems which include a transport membrane evaporator.BACKGROUND

[0003] Cooling and drying a fluid which contains water (a hydrated fluid), without utilizing an undue amount of energy is a challenging problem in several industrial applications. Examples of such industrial applications would be cooling and drying air in an air conditioning system or cooling and drying exhaust gas from an internal combustion engine in a bottoming cycle power system.

[0004] In the case of exhaust gas from an internal combustion engine, one of the most challenging aspects of today’s energy technologies is to effectively convert waste heat from the exhaust gas of a combustion process into useable power. Systems of converting waste heat into useful forms of energy are commonly referred to as bottoming cycle power systems, or other combustion systems such as gas or oil fired furnaces.

[0005] Bottoming cycle power systems often include an expansion turbine (or turboexpander) connected to a compression turbine (or turbo-compressor) via a common crankshaft. The exhaust gas flows through the turbo-expander where it may exit the turbo-expander at below atmospheric pressures (or vacuum pressures). The vacuum pressures are caused by the turbo-compressor, which pumps the exhaust gas back to atmospheric pressures as the exhaust gas exits the bottoming cycle power system. The amount of usable energy (or net-work) recovered from a bottoming cycle power system is the energy produced by the turbo-expander minus the energy consumed by the turbo-compressor. Therefore, the less work needed by the turbo-compressor to compress the expanded volume of exhaust gas, the greater the net-work produced from the bottoming cycle power system.

[0006] Various prior art cooling systems may be utilized to reduce the specific volume of exhaust gas prior to entering the turbo-compressor and, therefore, reduce the amount of work required by the turbo-compressor to compress the exhaust gas. Problematically however, these cooling systems consume a significant amount of energy due to pumps and / or other energy consuming devices needed to circulate coolants through the cooling system.

[0007] Further, the exhaust gas of an internal combustion engine contains a significant amount of water vapor. The water vapor has a relatively high specific volume and mass, which causes an unwanted burden on the compression work of the turbo-compressor. Problematically, removing the water from a flow of exhaust gas using current techniques often requires a significant amount of energy.

[0008] Additionally, it is highly desirable to remove carbon dioxide from the flow of exhaust gas from an internal combustion engine. However, water in the exhaust gas interferes with the process of removing carbon dioxide from the exhaust gas. Problematically, using current techniques, it is difficult to efficiently remove water from a flow of exhaust gas prior to removing carbon dioxide from the flow of exhaust gas.

[0009] Accordingly, there is a need for a system and method of cooling and drying a hydrated fluid without utilizing an undue amount of energy. There is a need for cooling and drying air in an air conditioning system with as little energy as possible. Further, there is also a need for cooling and drying exhaust gas from an internal combustion engine with as little energy as possible. Also, there is a need to efficiently remove water from a flow of exhaust gas prior to removing carbon dioxide from the flow of exhaust gas.BRIEF DESCRIPTION

[0010] The present disclosure offers advantages and alternatives over the prior art by providing a water removal system which includes a transport membrane evaporator system and a refrigeration system. The transport membrane evaporator system circulates refrigerant water acting as a first refrigerant through a transport membrane evaporator, a first condenser, a first water pump and an orifice. The refrigeration system circulates a second refrigerant though a refrigerant compressor, a second condenser, an orifice and a refrigerant evaporator. The refrigerant evaporator of the refrigeration system is in heat exchange communication with the first condenser of the transport membrane evaporator system. The water removal system efficiently removes water from a flow of hydrated fluid (such as air or exhaust gas from an internal combustion engine) to significantly dry the fluid.

[0011] A water removal system in accordance with one or more aspects of the present disclosure includes a transport membrane evaporator, a first condenser and a water pump all in fluid communication with each other and which operate to circulate refrigerant water acting as a first refrigerant therethrough. The transport membrane evaporator includes a first flow path and a second flow path. The first flow path is operable to flow the refrigerant water therethrough under a vacuum pressure that is low enough to vaporize the refrigerant water within the first flow path. The second flow path is operable to flow a fluid having water therethrough. Both water and heat are transferred from the fluid in the second flow path to the refrigerant water in the first flow path through a membrane-based material of the transport membrane evaporator, such that the fluid passing through the second flow path has at least a portion of its water removed and is cooled.

[0012] Some embodiments of the water removal system include a refrigeration system. The refrigeration system includes a refrigerant compressor, a second condenser and a refrigerant evaporator all in fluid communication with each other and which operate to circulate a second refrigerant therethrough. The refrigerant evaporator is in heat exchange communication with the first condenser and is configured to evaporate the second refrigerant in the refrigerant evaporator and to condense the refrigerant water and water from the fluid in the first condenser to transfer heat from the refrigerant water in the first condenser to the second refrigerant in the refrigerant evaporator.

[0013] In some embodiments of the water removal system, the vacuum pressure in the first flow path is maintained by: a. water from the fluid in the second flow path acting as a plug in the pores of the membranebased material as the water from the fluid passes through the pores, and b. refrigerant water and water from the fluid is condensed in the first condenser.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0015] FIG. 1 depicts an example of a water removal system having a transport membrane evaporator system and refrigeration system, according to aspects described herein;

[0016] FIG. 2 depicts an example of a cross sectional view of the transport membrane evaporator of the transport membrane evaporator system of the water removal system of FIG. 1, according to aspects described herein;

[0017] FIG. 3 depicts an example of a cross sectional view of a membrane tube of the transport membrane evaporator, according to aspects described herein;

[0018] FIG. 4 depicts an example of an enlarged view of the circular area 4-4 of FIG. 3, according to aspects described herein;

[0019] FIG. 5 depicts an example of a schematic view of the water removal system of FIG. 1, wherein the fluid to be cooled and dried includes a flow of exhaust gas from an internal combustion engine, according to aspects described herein;

[0020] FIG. 6 depicts an example of a flow diagram of a method of removing water from a fluid, according to aspects described herein; and

[0021] FIG. 7 depicts an example of a continuation of the method from FIG. 6, according to aspects described herein.DETAILED DESCRIPTION

[0022] Certain examples will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the methods, systems, and devices disclosed herein. One or more examples are illustrated in the accompanying drawings. Those skilled in the art will understand that the methods, systems, and devices specifically described herein and illustrated in the accompanying drawings are non-limiting examples and that the scope of the present disclosure is defined solely by the claims. The features illustrated or described in connection with one example may be combined with the features of other examples. Such modifications and variations are intended to be included within the scope of the present disclosure.

[0023] The terms "significantly", "substantially", "approximately", "about", “relatively,” or other such similar terms that may be used throughout this disclosure, including the claims, are used to describe and account for small fluctuations, such as due to variations in processing from a reference or parameter. Such small fluctuations include a zero fluctuation from the reference or parameter as well. For example, they can refer to less than or equal to ± 10%, such as less than or equal to ± 5%, such as less than or equal to ± 2%, such as less than or equal to ± 1%, such as less than or equal to ± 0.5%, such as less than or equal to ± 0.2%, such as less than or equal to ± 0.1%, such as less than or equal to ± 0.05%.

[0024] Referring to FIG. 1, an example is depicted of a water removal system 100, having a transport membrane evaporator system 102 and a refrigeration system 104.

[0025] The transport membrane evaporator system 102 includes a transport membrane evaporator 106, a first condenser 108, a first water pump 110 and a first orifice 112 all in fluid communication with each other and which operate to circulate water acting as a first refrigerant 114 therethrough. The water acting as a first refrigerant may be referred to herein as “refrigerant water” 114 or may be referred to as “R718”, which is the international designation for water as a refrigerant.

[0026] The transport membrane evaporator 106 includes a first flow path 116 and a second flow path 118. The first flow path 116 is operable to flow the refrigerant water 114 therethroughunder a vacuum pressure that is low enough to vaporize the refrigerant water 114 within the first flow path 116. The second flow path 118 is operable to flow a fluid 120 having water 168 (see FIGS. 3 and 4) therethrough.

[0027] The fluid 120 may be any of a number of fluids that have water therethrough (e.g., a hydrated fluid). For example, the fluid may be air containing moisture. Also, by way of example, the fluid may be an exhaust gas from any number of combustion processes, which have water as a byproduct of the combustion process. The combustion processes may be, for example, from a coal fired power plant, a steam boiler system or an internal combustion engine. The exhaust gas / fluid 120 from the combustion processes may contain water, carbon dioxide and other byproducts of combustion, such as nitrogen.

[0028] As the fluid 120 flows through the second flow path 118, both water 168 and heat are transferred from the fluid 120 in the second flow path 118 to the refrigerant water 114 in the first flow path 116 through pores 166 of a membrane-based material (such as, for example, a tube wall 162 of a ceramic membrane tube 156 (see FIGS. 3 and 4)) of the transport membrane evaporator 106.

[0029] Accordingly, the fluid 120 passing through the second flow path 118 has at least a portion of its water 168 removed and is cooled. Also accordingly, the water exiting the transport membrane evaporator 106 and entering the first condenser 108 is in the form of a flow of steam 136, which includes a combination of the vaporized refrigerant water 114 and vaporized water 168 from the fluid 120. The combination of the refrigerant water 114 and water 168 from the fluid 120 may be referred to herein as the combined water 114, 168.

[0030] The transport membrane evaporator 106 and first condenser 108 are shown in FIG. 1 as two separate discrete devices. However, it is within the scope of this disclosure that the transport membrane evaporator 106 and second condenser 108 may be combined into one device performing both the evaporating function and the condensing function in series.

[0031] The refrigeration system 104, in this example is a vapor compression refrigeration system. However, other types of refrigeration systems, such as, for example, an absorption chiller refrigeration system (not shown), may be used. The refrigeration system 104 includes a refrigerantcompressor 124, a second condenser 126, a second orifice 128 and a refrigerant evaporator 130 all in fluid communication with each other and which operate to circulate a second refrigerant 132 therethrough. As will be explained in greater detail herein, the refrigerant evaporator 130 of the refrigeration system 104 is in heat exchange communication with first condenser 108 of the transport membrane evaporator system 102. In this example, evaporator coils 134 of the refrigerant evaporator 130 are positioned within the first condenser 108. The evaporator coils 134 are configured to evaporate the second refrigerant 132 in the refrigerant evaporator 130 and to condense the combined water 114, 168 in the first condenser 108. This results in the transfer of heat from the combined water 114, 168 in the first condenser 108 to the second refrigerant 132 in the refrigerant evaporator 130.

[0032] During operation of the water removal system 100, a vacuum pump 122, or similar device, is used to pull a predetermined vacuum pressure in the first flow path 116 of the transport membrane evaporator 106. Thereafter, the first water pump 110 is turned on to start the flow of refrigerant water 114 from the first condenser 108 (which is connected to the suction side of the first water pump 110) toward the first orifice 112 (which is connected to the high pressure side of the first water pump 110).

[0033] The first orifice 112 may be, for example, a simple restriction or a throttle valve or the like, which reduces the pressure abruptly as the refrigerant water 114 passes through the first orifice 112 and into the first flow path 116 of the transport membrane evaporator 106. The vacuum pressure in the first flow path 116 causes the refrigerant water 114 to vaporize in the transport membrane evaporator 106. The vacuum pressure in the first flow path 116 is low enough to vaporize the water refrigerant 114 at a predetermined temperature, such as from about 50 degrees Fahrenheit to about 60 degrees Fahrenheit. Such a vacuum pressure may be, for example, between about 0.2 and 0.3 pounds per square inch absolute (psia).

[0034] The water 168 from the fluid 120 in the second flow path 118 flows through pores 166 (see FIG. 4) in the membrane material and mixes with the refrigerant water 114 to provide a total flow of combined water 114, 168 in the first flow path 116. The combined water 114, 168 flows as a flow of steam 136 through the first flow path 116 into the first condenser 108. The evaporator coils 134 in the first condenser 108 then condenses the combined water 114, 168.

[0035] The water 168 from the fluid 120 that is condensed in the first condenser 108, may be pumped out of the system 100 via a second water pump 138 and into a holding tank 140. The first water pump 110 may then pump the refrigerant water 114 back toward the transport membrane evaporator 106 to start the cycle over again.

[0036] The first and second water pumps 110, 138 are shown in FIG. 1 as two separate discrete devices. However, it is within the scope of this disclosure that a single pump, or a single pump and valve combination, may be used to perform the functions of both the first and second pumps 110, 138. For example, a single pump may be used to pump the combined water 114, 168 toward the first orifice 112, while a tee in the line between the single pump and first orifice (not shown) may be used to tee off the water 168 from the fluid 120, so that only the refrigerant water 114 reaches the first orifice 112.

[0037] The vacuum pump 122, that pulled the initial vacuum on the transport membrane evaporator 106 may be turned off during operation of the water removal system 100. The vacuum pressures in the transport membrane evaporator system 102 may be maintained, even with the vacuum pump 122 turned off, as long as the water 168 from the fluid 120 is flowing through the pores 166 (see FIG. 4), and the refrigerant evaporator 130 is condensing the combined water 114, 168 in the first condenser 108. This is because the water 168 flowing through the pores 166, acts as a plug, which plugs the pores to substantially make the transport membrane evaporator system a closed circuit. Additionally, the reduction in volume of combined water 114, 168 as it condenses in the first condenser 108, acts as a vacuum pump to help maintain the vacuum pressure in the transport membrane evaporator 106.

[0038] The refrigeration system 104 includes the refrigerant compressor 124, the second condenser 126, the second orifice 128 and the refrigerant evaporator 130 all in fluid communication with each other and which operate to circulate the second refrigerant 132 therethrough. The second refrigerant 132 may be, for example, R-22, R-134A, R-471 A or the like. A commercial example of refrigerant R-471 A is sold under the brand name: Solstice® N71, which is manufactured by Honeywell International, Inc, having a corporate headquarters in Charlotte, North Carolina, USA.

[0039] During operation of the refrigerant system 104, the second refrigerant 132 enters the refrigerant compressor 124 as a low pressure and low temperature vapor or gas. Then the pressure and temperature of the second refrigerant 132 is increased, as the refrigerant compressor 124 does compression work on the second refrigerant 132. The second refrigerant 132 then leaves the refrigerant compressor 124 as a higher temperature and higher pressure (often superheated) gas. The second refrigerant 132 then passes through the second condenser 126 where it releases heat to the surroundings as it cools and condenses (for example, at about 140 degrees Fahrenheit (F) to 180 degrees Fahrenheit (F)). The cooler high-pressure liquid second refrigerant 132 next passes through a second orifice 128, which reduces the pressure abruptly causing the temperature to drop substantially. The second orifice 128 may be, for example, a simple restriction or an expansion valve or a throttle valve or the like.

[0040] The colder low pressure mixture of liquid and vapor second refrigerant 132 next travels through the refrigerant evaporator 130. In this case, the second refrigerant flows into the evaporator coils 134 of the refrigerant evaporator 130. In the evaporator coils 134, the second refrigerant 132 vaporizes (for example, at about 25 degrees F to 35 degrees F) as it accepts heat from the condensing combined water 114, 168 in the first condenser 108. The vaporized second refrigerant 132 then flows back to the suction side of the refrigerant compressor 124 to start the cycle over again.

[0041] The refrigerant evaporator 130 is in heat exchange communication with the first condenser 108 of the transport membrane evaporator system 102. The refrigerant evaporator 130 is configured to evaporate the second refrigerant 132 to transfer (or absorb) heat from the combined water 114, 168 in the first condenser 108 to the second refrigerant 132. The refrigerant evaporator 130 may be, for example, configured to evaporate the second refrigerant 132 within a temperature range of about 25 degrees Fahrenheit to about 35 degrees Fahrenheit. In the example illustrated in FIG. 1, evaporator coils 134 of the evaporator 130 are positioned within the first condenser 108 and are an integral part of the refrigerant evaporator 130, wherein the second refrigerant 132 circulates through the evaporator coils 134 and evaporates therein.

[0042] However, several other configurations are also within the scope of this disclosure that would enable the heat pump evaporator 130 to be in heat exchange communication with thefirst condenser 108. For example, the second refrigerant 132 may be in heat exchange communication with the combined water 114, 168 through a separate and distinct combined water 114, 168 to second refrigerant 132 heat exchanger (not shown), wherein the second refrigerant 132 evaporates, and the combined water 114, 168 is cooled, within the separate water to second refrigerant heat exchanger. Also, by way of example, the combined water 114, 168 may be circulated from the first condenser 108 into the main body of the refrigerant evaporator 130 to be cooled therein.

[0043] Advantageously, the refrigeration system 104 cools the combined water 114, 168 in the first condenser 108 more efficiently than, for example, using a water tower. Also advantageously, the vacuum within the transport membrane evaporator 106 may be maintained without the use of the vacuum pump 122 by thereafter utilizing the flow of water 168 from the fluid 120 to plug the membrane pores 166 and the condensation of the combined water 114, 168 in the first condenser 108 to continue pulling a vacuum. As a result, water removal from a flow of fluid can be accomplished more efficiently and with smaller sized equipment than prior art systems.

[0044] The transport membrane evaporator 106 includes membrane-based material (such as, for example, membrane tubes 156 (see FIG. 2)) through which both heat energy and mass (such as water) can flow. Membrane-based materials and membrane-based devices (such as vapor permeation membranes, membrane condensers and transport membrane heat exchangers (sometimes known as transport membrane condensers)) can transport heat energy and selectively water molecules, so that they may be used as a tool to control the flow of heat and water across the membrane-based material. Accordingly, membrane-based materials can be utilized to cool and dry certain fluids, such as air or exhaust gas from an internal combustion engine.

[0045] The membrane-based material may, for example, be a porous fine material, which may be sintered from Alumina, Titania or Zirconia. The membrane-based material may be composed of a hydrophobic polymer membrane, which may have pore sizes within a variety of ranges. For example, the pore sizes may be within a range of about: 0.1 to 0.2 micrometers, 0.2 micrometers or less, 0.1 micrometers or less, 0.5 micrometers or less, 0.2 micrometers or less, 0.1 micrometers or less, or 0.01 to 0.02 micrometers.

[0046] The membrane-based material may employ hydrophilic ceramic membranes with a high thermal conductivity to condense water vapors within the membrane pores. The membranebased material may also include polymeric membrane material, such as a block copolymer or a sulfonated poly(ether ether ketone) (i.e., SPEEK). The membrane-based material may be a ceramic or may be a non-ceramic material.

[0047] As stated earlier, the transport membrane evaporator 106 includes a first flow path 116 and a second flow path 118 (see FIG. 2). The first flow path 116 is operable to flow the refrigerant water 114 therethrough under a vacuum pressure that is low enough to vaporize the water acting as a first refrigerant 114 within the first flow path 116. It is advantageous that the first flow path 116 of the transport membrane evaporator 116 be operable to flow the refrigerant water 114 under vacuum pressures that induces evaporation of the refrigerant water 114.

[0048] One of the reasons this is advantageous is because this helps to maintain a large pressure differential across the membrane-based materials, which enhances the migration of water across the membrane. Another reason this is advantageous is because, as water 168 (see FIG. 4) contained in a fluid 120 in the second flow path 118 migrates across the membrane-based materials, the water 168 almost simultaneously condenses out of the fluid 120 in the second flow path 118 as the water 168 passes through the porous walls of the membrane-based materials and evaporates into a gas as the water 168 mixes with the evaporated water acting as a first refrigerant 114 in the first flow path 116. Accordingly, the latent heat of vaporization of water is almost balanced out (or nullified) by the change of state of the water 168 from gas (in the second flow path 118) to liquid (in the pours 166 of the membrane-based material) and back to a gas again (in the first flow path 116). Accordingly, because the latent heat of vaporization of the water 168 from the fluid 120 in the second flow path 118 does not have to be absorbed by the evaporated refrigerant water 114 in the first flow path 116, there is much less flow required for the refrigerant water 114 to absorb the same amount of water 168 migrating across the membrane-based material than if the refrigerant water 114 were not evaporating. For example, there may be as much as one half to one tenth the amount of volume of water flow of the refrigerant water 114 required to migrate the water 168 from the fluid 120 in the second path 118 when the refrigerant water 114 is evaporated than when it is not evaporated. This substantially downsizes the transport membrane evaporator 106 and helps to increase the overall efficiency of the entire water removal system 100.

[0049] The flow of fluid 120 in the second flow path 118 may be air or may be a flow of exhaust gas 216 from an internal combustion engine 202 (see FIG. 5). If the flow of fluid 120 is exhaust gas 216, then the second flow path 118 may be operable to flow the exhaust gas 216 therethrough under a vacuum pressure. However, advantageously, the vacuum pressure in the second flow path 120 may be at a greater pressure than the vacuum pressure in the first flow path 116. As such, the pressure differential is advantageously from the higher absolute pressure in the second flow path 118 (through which the hydrated fluid 120 flows) to the lower absolute pressure in the first flow path 116 (through which the water acting as a first refrigerant 114 flows). This pressure differential across the membrane-based material (such as membrane tubes 156 (see FIG. 2)) of the transport membrane evaporator 106 enhances the migration of water 168 in the fluid 120 to the refrigerant water 114. The water 168 transferred from the fluid 120 in the second flow path 118 mixes with the refrigerant water 114 in the first flow path 116 to form a flow of combined water 114, 168. The flow of combined water 114, 168 in the first flow path 134 flows as a flow of steam 136 from the transport membrane evaporator 106 to the first condenser 108.

[0050] Accordingly, in the water removal system 100 of the present disclosure, removing the latent heat of vaporization of the water 168 from the fluid 120 is not performed in the transport membrane evaporator. Rather it is delayed until the water 168 from the fluid 120 reaches the first condenser 108, where removal of the latent heat of vaporization of the water 168 from the fluid 120 can advantageously be done much more efficiently by the evaporator coils 134 of the refrigeration system 104.

[0051] Also advantageously, the pressures within the first flow path 116 may be under a vacuum pressure that is low enough to vaporize the refrigerant water 114 within the first flow path 116, which greatly enhances the transfer of heat energy from the fluid 120 to the refrigerant water 114 without raising the temperature of the refrigerant water 114. For example, at a vacuum pressure of about 0.2 psia in the first flow path 116, the refrigerant water 114 would evaporate at about 50 degrees Fahrenheit (F). This would provide an extremely effective cooling effect, since the latent heat of vaporization of water is larger than almost any other commercially available refrigerant, i.e., about 40.65 kilojoules per mole, or about 2230 joules per gram or about 533 calories per gram of water. Accordingly, a great deal of heat energy from the fluid 120 (e g., air orexhaust gas) would be absorbed by the vaporizing refrigerant water 114 without raising the temperature of the refrigerant water 114.

[0052] Referring to FIGS. 2 and 3, an example is depicted of a cross sectional view of the transport membrane evaporator 106 (FIG. 2) and a cross sectional view of a membrane tube 156 (FIG. 3) of the transport membrane evaporator 106, according to aspects described herein. The membrane-based material of the transport membrane evaporator 106 includes a plurality of membrane tubes 156. Each tube 156 of the plurality of tubes 156 includes an outside diameter 158, an inside diameter 160 and a porous tube wall 162 therebetween. The inside diameter 160 of each tube 156 defines a tube passageway 164 therethrough. The first flow path 116 (through which the refrigerant water 114 flows) extends through a refrigerant entrance manifold 170 of the transport membrane evaporator 106 and into the tube passageway 164 of each tube 156. The first flow path 116 then extends from the tube passageway 164 of each tube 156 of the plurality of tubes 156 through a refrigerant exit manifold 172 of the transport membrane evaporator 106 to exit the evaporator 106 and flow into the first condenser 108. The vacuum pump 122 (see FIG. 1), may be connected to the refrigerant entrance manifold 170.

[0053] The second flow path 118 (through which the hydrated fluid 120 flows) extends through a fluid input port 174 of an evaporator outer shell 180 of the transport membrane evaporator 106. The evaporator outer shell 180 provides a hollow interior 184, which encloses the plurality of tubes 156. The evaporator outer shell 180 is operable to withstand total vacuum pressures (e.g., up to 14.7 psia and more) without being damaged.

[0054] Once the hydrated fluid 120 flows through the fluid input port 174, it follows the second flow path 118, which extends around the outside diameter 158 of each membrane tube 156. Additionally, the second flow path 118 is directed laterally back and forth by a series of baffles 182 in a sinuous path as the second flow path 118 travels longitudinally along the hollow interior 184 toward an output port 176 of the transport membrane evaporator 106. The hollow interior 184 of the transport membrane evaporator 106 is sealed off from the refrigerant entrance manifold 170 and refrigerant exit manifold 172 by a pair of interior end walls 186, which are positioned on opposing longitudinal ends of the evaporator outer shell 180. The distal ends of each membrane tube 156 extend through each interior end wall 186 to enable the refrigerant water 114 to enter andexit the tube passageways 164 without mixing with the fluid 120 flowing through the second flow path 118 in the hollow interior 184 of the shell 180 of the transport membrane evaporator 106.

[0055] The second flow path 118 then extends through the output port 176 of the transport membrane evaporator 106 to exit the evaporator 106. The fluid 120 which exits the output port 176 is now significantly cooled and dried of moisture. This is because, both water 168 and heat from the fluid 120 passing through the second flow path 118 migrate through the tube walls 162 of each tube 156 to the refrigerant water 114 in the first flow path 116.

[0056] The first flow path 116 extends through the tube passageway 164 of each membrane tube 156. Therefore, the membrane tubes 156 are operable to flow the refrigerant water 114 therethrough under a vacuum pressure that is low enough to vaporize the refrigerant water 114 within the tube passageways 164. For example, the pressures within the tube passageways 164 may be at a pressure of about 5 psia or less, 4 psia or less, 3 psia or less, 2 psia or less, 1 psia or less, 0.2 psia or less, 0.12 psia or less or 0.1 psia or less.

[0057] Accordingly, the refrigerant water 114 in each of the tube passageways 164 will be vaporized due to the low vacuum pressures. It is advantageous to vaporize the refrigerant water 114 within the tube passageways 164 because this helps to maintain a large pressure differential across the membrane-based tube walls 162, which enhances the migration of water 168 (see FIG. 4) across the membrane walls 162. Additionally, it is advantageous to vaporize the refrigerant water 114 within the tube passageways 164 because the heat energy of the fluid 120 in the second flow path 118 is readily absorbed by the refrigerant water 114 to overcome the latent heat of vaporization of the evaporating refrigerant water 114, which greatly enhances the heat transfer from fluid 120 to refrigerant water 114. Another reason this is advantageous is because, as water 168 (see FIG. 4) contained in the fluid 120 in the second flow path 118 migrates across the membrane-based materials, the water 168 almost simultaneously condenses out of the fluid in the second flow path 118 as the water 168 passes through the porous walls of the membrane-based materials and evaporates into a gas as the water 168 mixes with the evaporated refrigerant water 114 in the first flow path 116. Accordingly, the latent heat of vaporization of water is almost balanced out (or nullified) by the change of state of the water 168 from gas (in the second flow path 118) to liquid (in the pours 166 of the membrane-based material) and back to a gas again (inthe first flow path 1 16). Accordingly, because the latent heat of vaporization of water 168 from the fluid 120 does not have to be absorbed by the evaporating refrigerant water 114 in the first flow path 116, there is much less flow required for the refrigerant water 114 to absorb the same amount of water 168 migrating across the membrane-based material than if the refrigerant water 114 were not evaporating. This substantially downsizes the transport membrane evaporator 106 and helps to increase the overall efficiency of the entire water removal system 100.

[0058] For example, at a vacuum pressure of 0.2 psia in the tube passageways 164, the refrigerant water 114 would evaporate at about 50 degrees Fahrenheit (F). This would provide an extremely effective cooling effect, since the latent heat of vaporization of water is larger than almost any other commercially available refrigerant, i.e., about 40.65 kilojoules per mole, or about 2230 joules per gram or about 533 calories per gram of water. Accordingly, a great deal of heat energy from the fluid 120 (e.g., air or exhaust gas) would be absorbed by the vaporizing refrigerant water 114 without raising the temperature of the refrigerant water 114. Additionally, a positive pressure differential from fluid 120 in the second flow path 118 to the refrigerant water 114 in the first flow path 116 would be maintained in about a range of 10 to 15 pounds per square inch (psi), which would greatly enhance the migration of water 168 across the tube walls 162.

[0059] Also advantageously, the vacuum pressures (e.g., 0.2 psia) may be maintained in the tube passageways 164 even without the use of the vacuum pump 122 as long as the water 168 from the hydrated fluid 120 is flowing across the pores 166 of the membrane material and the condenser 108 is condensing the combined water 114, 168. This is because the water 168 in the pores 166 of the membrane material functions as a plug or seal on the vacuum pressure in the passageways 164 and the reduction in volume of the condensed combined water 114, 168 in the condenser 108 functions as a vacuum pump on the passageways 164.

[0060] Referring to FIG. 4, an example is depicted of an enlarged view of the circular area 4-4 of FIG. 3, according to aspects described herein. The enlarged view is a cross sectional view of the tube wall 162 of the membrane tubes 156.

[0061] The tube wall 162 is composed of a membrane-based material having a large number of pores 166 extending therethrough. In this case, the tube walls 162 are composed of a membrane based material. The membrane-based material may, for example, be a porous finematerial, which may be sintered from Alumina, Titania or Zirconia. The membrane-based material may be composed of a hydrophobic polymer membrane, which may have pores 166 with pore sizes within a variety of ranges. For example, the pore sizes of the pores 166 may be within a range of: about 0.1 to 0.2 micrometers, 0.2 micrometers or less, 0.1 micrometers or less, 0.5 micrometers or less, 0.2 micrometers or less, 0.1 micrometers or less, or about 0.01 to 0.02 micrometers.

[0062] The membrane-based material may employ hydrophilic ceramic membranes with a high thermal conductivity to condense water vapors within the membrane pores. The membranebased material may include a block copolymer or a sulfonated poly(ether ether ketone) (i.e., SPEEK). The membrane-based material may be a ceramic material or a non-ceramic material.

[0063] As illustrated in FIG. 4, the water or moisture 168 selectively migrates from the fluid 120 passing through the second flow path 118, through the pores 166 of the membrane based material, and into the refrigerant water 114 passing through the first flow path 116.

[0064] Referring to FIG. 5, an example is depicted of a schematic view of the water removal system 100 of FIG. 1, wherein the fluid 120 includes a flow of exhaust gas 216 from an internal combustion engine 202 of a primary power supply 200, according to aspects described herein. The primary power supply 200 includes the engine 202 having a crankshaft 205, which is connected to a primary generator 204.

[0065] The exhaust gas 216 flows from the engine 202 and may enter a turbine-generator system 206. The turbine generator system 206 may advantageously be utilized to supply electrical power to the water removal system 100. The turbine-generator system 206 is a form of bottoming cycle power system, that can be used to supply a portion of, or all, electrical power requirements of the water removal system 100. Such bottoming system power systems are described in issued patent no. 11,415,052, filed on September 27, 2021, titled: SYSTEMS AND METHODS ASSOCIATED WITH BOTTOMING CYCLE POWER SYSTEMS FOR GENERATING POWER AND CAPTURING CARBON DIOXIDE, and in issued patent no. 11,346,256, filed on September 27, 2021, titled: SYSTEMS AND METHODS ASSOCIATED WITH BOTTOMING CYCLE POWER SYSTEMS FOR GENERATING POWER, CAPTURING CARBON DIOXIDE AND PRODUCING PRODUCTS, both of which are incorporated herein by reference in their entirety.

[0066] The turbine-generator system 206 includes a turbo-expander 208 and turbocompressor 212 disposed on a turbo-crankshaft 210. The turbo-expander 208 operates to rotate the turbo-crankshaft 210 as the flow of exhaust gas 216 from the engine 202 passes through the turboexpander 208. The turbo-compressor 212 operates to compress the flow of exhaust gas 216 after the exhaust gas 216 passes through the turbo-expander 208. A bottoming cycle generator 214 may be disposed on the turbo-crankshaft 210. The bottoming cycle generator 214 may be connected to the water removal system 100. The bottoming cycle generator 214 may operate to provide at least a portion of electric power required to operate the water removal system 100.

[0067] During operation, the exhaust gas 216 from the internal combustion engine 202 enters and expands in the turbo-expander 208. By way of example, the exhaust gas 216 could enter the turbo-expander 208 at about 700 to 900 degrees Fahrenheit (F) and about 10 psi above atmospheric pressure. By doing so, the exhaust gas 216 does work by initiating rotation of the turbo-crankshaft 210 which rotates the turbo-compressor 212 and the bottoming cycle generator 214. Rotation of the turbo-compressor 212 results in a vacuum (for example, a vacuum in a range of about 4 to 10 psi below atmospheric pressure or about 10.7 to 4.7 pounds per square inch absolute (psia)) being pulled on the exhaust gas 216 as it passes through the turbo-expander 208. This vacuum pressure range advantageously increases the pressure differential across the turboexpander 208 and, therefore, enhances the total power that can be generated by the bottoming cycle generator 214.

[0068] The exhaust gas 216 exits the turbo-expander 208 and then flows into the second flow path 118 of the transport membrane evaporator 106 of the transport membrane evaporator system 102. More specifically in this example, the exhaust gas 216 enters the tube passageways 164 of the membrane tubes 156.

[0069] Advantageously, even though there is a substantial vacuum on the flow of exhaust gas 216 out of the turbo-expander 208 (which, in this example, is functioning as the hydrated fluid 120 in the second flow path 118 of the transport membrane evaporator 106), the absolute pressures of the exhaust gas 216 in the second flow path 118 are configured to be substantially greater than the absolute pressures of the refrigerant water 114 evaporating in the first flow path 116 of the transport membrane evaporator 106. For example, the pressure on the exhaust gas 216 in thesecond flow path 1 18 may be configured to be about 10.6 to 4.6 psia greater than the pressure on the evaporating refrigerant water 114 in the membrane tubes 156 of the first flow path 116. This positive pressure across the walls 162 of the membrane tubes 156 greatly enhances the migration of moisture 168 from exhaust gas 216 to refrigerant water 114 in the transport membrane evaporator 106.

[0070] The exhaust gas 216 then exits the transport membrane evaporator 106 as cooled and dried exhaust gas 216. The exhaust gas 216 then flows into the turbo-compressor 212 of the turbine generator system 206, where it is compressed back to atmospheric pressures or greater. From the turbo-compressor 212, the cooled and dried exhaust gas 216 may flow into a carbon dioxide capture system 220, which removes the carbon dioxide from the exhaust gas 216. Advantageously, the carbon dioxide capture system functions more efficiently with the water 168 removed from the exhaust gas 216 and with the exhaust gas 216 cooled. From the carbon dioxide capture system 220, the exhaust gas 216 may flow up a stack 221 associated with the internal combustion engine 202.

[0071] Referring to FIG. 6, an example is depicted of a flow diagram of a method 300 of removing water 168 from a fluid 120, according to aspects described herein. The fluid 120 may be air or may be exhaust gas 216 from an internal combustion engine 202.

[0072] The method 300 starts at 302. At 302, refrigerant water 114, acting as a refrigerant, is flowed through a first flow path 116 of a transport membrane evaporator 106 of a transport membrane evaporator system 102. The transport membrane evaporator system includes the transport membrane evaporator, a first condenser, a first water pump and a first orifice all in fluid communication with each other and which operate to circulate the refrigerant water in a cycle.

[0073] At 304, a fluid 120 having water 168 therethrough (or contained therein), is directed to flow through a second flow path 118 of the transport membrane evaporator 106. The fluid 120 may be, for example, air or exhaust gas 216 from a internal combustion engine 202 (see FIG. 5).

[0074] At 306, a vacuum is pulled on the refrigerant water 1 14 in the first flow path 1 16. The vacuum is low enough to vaporize the refrigerant water 114 within the first flow path 116. The vacuum may be initially pulled via a vacuum pump 122. Thereafter the vacuum pump 122 may be shut off and the vacuum may be maintained within the first flow path 116 at least by condensing the combined water 114, 168 in the first condenser 108 to substantially reduce the volume of the combined water 114, 168. The vacuum may be further maintained within the first flow path 116 at least by substantially plugging the pores 166 of the membrane-based material with condensed water 168 from the fluid 120.

[0075] At 308, water 168 may be transferred from the fluid 120 in the second flow path 118 to the refrigerant water 114 in the first flow path 116 through pores 166 in the membranebased material of the transport membrane evaporator 106, such that the fluid 120 passing through the second flow path 118 has at least a portion of the water 168 within the fluid 120 removed.

[0076] Referring to FIG. 7, an example is depicted of a continuation of the method 300 from FIG. 6, according to aspects described herein.

[0077] At 310, the water 168 from the fluid 120 that passes through the pores 166 of the membrane-base material is combined with the refrigerant water 114 to form a flow of vaporized combined water 114, 168, wherein the combined water 114, 168 flows into the first condenser 108.

[0078] At 312, a second refrigerant 132 is evaporated in evaporator coils 134 of a refrigerant evaporator 130 of a refrigeration system 104. The evaporator coils 134 are in heat exchange communication with the first condenser 108.

[0079] At 314, heat is transferred from the combined water 114, 168 into the second refrigerant 132 to condense the combined water 114, 168 within the first condenser 108, as the second refrigerant evaporates 132 within the evaporator coils 134.

[0080] At 316, the condensed water 168 from the fluid 120 is removed from the combined water 114, 168 to leave substantially just the condensed refrigerant water 114.

[0081] At 318, the condensed refrigerant water 114 is pumped via the first water pump 110 through the first orifice 112 to substantially reduce the pressure of the condensed refrigerant water 114.

[0082] At 320, the condensed refrigerant water 114 is flowed back into the first flow path 116 of the transport membrane evaporator 106 to repeat the cycle.

[0083] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail herein (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein.

[0084] Although the invention has been described by reference to specific examples, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the disclosure not be limited to the described examples, but that it have the full scope defined by the language of the following claims.

Claims

CLAIMSWhat is claimed is:

1. A water removal system comprising: a transport membrane evaporator system having a transport membrane evaporator, a first condenser and a first water pump all in fluid communication with each other and which operate to circulate refrigerant water acting as a first refrigerant therethrough; the transport membrane evaporator comprising a first flow path and a second flow path, the first flow path being operable to flow the refrigerant water therethrough under a vacuum pressure that is low enough to vaporize the refrigerant water within the first flow path, the second flow path being operable to flow a fluid having water therethrough; and wherein both water and heat are transferred from the fluid in the second flow path to the refrigerant water in the first flow path through pores in a membrane-based material of the transport membrane evaporator, such that the fluid passing through the second flow path has at least a portion of its water removed and is cooled.

2. The water removal system of claim 1, comprising: a refrigeration system comprising a refrigerant compressor, a second condenser and a refrigerant evaporator all in fluid communication with each other and which operate to circulate a second refrigerant therethrough; and wherein the refrigerant evaporator is in heat exchange communication with first condenser and is configured to evaporate the second refrigerant in the refrigerant evaporator and to condense the refrigerant water and water from the fluid in the first condenser to transfer heat from the refrigerant water in the first condenser to the second refrigerant in the refrigerant evaporator.

3. The water removal system of claim 2, wherein: the vacuum pressure in the first flow path is maintained by:water from the fluid in the second flow path acting as a plug in the pores of the membrane-based material as the water from the fluid passes through the pores, and refrigerant water and water from the fluid is condensed in the first condenser.

4. The water removal system of claim 2, comprising: a suction side of the first water pump is in fluid communication with the first condenser and a high pressure side of the first water pump is in fluid communication with an orifice of the transport membrane evaporator system; wherein the water from the fluid that has condensed in the first condenser is removed from the water removal system; and wherein the refrigerant water that has condensed in the first condenser is pumped via the first water pump to the orifice.

5. The water removal system of claim 4, wherein the water from the fluid that has condensed in the first condenser is pumped from the water removal system via a second water pump.

6. The water removal system of claim 4, comprising: the orifice being in fluid communication with the first flow path of the transport membrane evaporator; and wherein the pressure in the refrigerant water passing through the orifice is dropped to the vacuum pressure in the first flow path.

7. The water removal system of claim 2, wherein: the vacuum pressure in the first flow path is low enough to vaporize the refrigerant water within a temperature range of 50 to 60 degrees Fahrenheit (F).

8. The water removal system of claim 2, wherein: the second refrigerant in the refrigerant evaporator is operable to evaporate within a temperature range of 25 to 40 degrees Fahrenheit.

9. The water removal system of claim 1, comprising: the membrane-based material of the transport membrane heat exchanger comprising a plurality of membrane tubes, each tube of the plurality of tubes comprising an outside diameter, an inside diameter and a porous tube wall therebetween, the inside diameter of each tube defining a tube passageway therethrough; the first flow path extending through the tube passageway of each tube; the second flow path extending around the outside diameter of each tube; and wherein, both water and heat from the fluid passing through the second flow path migrates through the tube walls of each tube to the refrigerant water in the first flow path.

10. The water removal system of claim 1, wherein the membrane-based material is a ceramic membrane-based material.

11. The water removal system of claim 1, wherein the fluid in the second flow path comprises a flow of air.

12. The water removal system of claim 1, wherein the fluid in the second flow path comprises a flow of exhaust gas from a combustion process.

13. The water removal system of claim 12, wherein the fluid in the second flow path comprises a flow of exhaust gas from an internal combustion engine.

14. The water removal system of claim 12, wherein the fluid in the second flow path comprises a flow of exhaust gas from a coal fired power plant.

15. The water removal system of claim 12, comprising: the second flow path operable to flow the exhaust gas therethrough under a vacuum pressure, the vacuum pressure in the second flow path being greater than the vacuum pressure in the first flow path.

16. The water removal system of claim 12, wherein:the exhaust gas is used to generate electric power from a bottoming cycle generator; and the electric power is used to provide electric power to the water removal system.

17. The water removal system of claim 12, wherein the exhaust gas is routed through a carbon dioxide capture system after the water has been removed from the exhaust gas by the water removal system.

18. The water removal system of claim 15, wherein the vacuum pressure in the second flow path is greater than the vacuum pressure in the first flow path by about 4.6 psi or greater.

19. The water removal system of claim 1 , wherein the first flow path is operable to flow the refrigerant water therethrough under a vacuum pressure that is between about 0.2 psia 0.3 psia.

20. A method of removing water from a fluid, the method comprising: flowing refrigerant water, acting as a refrigerant, through a first flow path of a transport membrane evaporator of a transport membrane evaporator system, the transport membrane evaporator system including the transport membrane evaporator, a first condenser, a first water pump and a first orifice all in fluid communication with each other and which operate to circulate the refrigerant water in a cycle; flowing a fluid having water therethrough through a second flow path of the transport membrane evaporator; pulling a vacuum on the refrigerant water in the first flow path low enough to vaporize the refrigerant water within the first flow path; and transferring water from the fluid in the second flow path to the refrigerant water in the first flow path through pores in a membrane-based material of the transport membrane evaporator, such that the fluid passing through the second flow path has at least a portion of the water within the fluid removed.21 . The method of claim 20, comprising: combining the water from the fluid that passes through the pores of the membrane-base material with the refrigerant water to form a flow of vaporized combined water, wherein the combined water flows into the first condenser; evaporating a second refrigerant in evaporator coils of a refrigerant evaporator of a refrigeration system, wherein the evaporator coils are in heat exchange communication with the first condenser; and transferring heat from the combined water into the second refrigerant to condense the combined water within the first condenser, as the second refrigerant evaporates within the evaporator coils.

22. The method of claim 21, comprising: removing the condensed water from the fluid from the combined water to leave substantially just the condensed refrigerant water; pumping the condensed refrigerant water via the first water pump through the first orifice to substantially reduce the pressure of the condensed refrigerant water; and flowing the condensed refrigerant water back into the first flow path of the transport membrane evaporator to repeat the cycle.

23. The method of claim 20, comprising: pulling the vacuum within the first flow path via a vacuum pump, wherein the vacuum is low enough to vaporize the refrigerant water within the first flow path; and thereafter shutting the vacuum pump off and maintaining the vacuum within the first flow path at least by condensing the combined water in the first condenser to substantially reduce its volume.

24. The method of claim 23, comprising: further maintaining the vacuum within the first flow path at least by substantially plugging pores of the membrane-based material with condensed water from the fluid.

25. The method of claim 20, wherein the fluid is one of air or exhaust gas from a combustion process.

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