Moisture can be separated or removed from a gas for various purposes such as industrial processes or air conditioning.
For example, conventional vapor compression air conditioning (VCC) systems generally do not provide direct control of humidity of conditioned air. However, humidity control is often required, and is provided with VCC systems by direct expansion of refrigerant to a temperature below the dew point of the air being conditioned. This results in condensation of atmospheric moisture at the VCC system evaporator. Air flowing across the evaporator coils is typically at or near the saturation temperature for a given pressure and is colder than the temperature needed for conditioned air, and is often re-heated to provide conditioned air at desired temperature and humidity levels.
In some embodiments of this disclosure, a moisture separation system comprises a water absorption vessel comprising a microemulsion disposed therein. The water absorption vessel also comprises a gas inlet in fluid communication with a gas source of gas comprising moisture to be removed and a gas outlet. The system also includes a gas-liquid phase separator comprising an inlet in fluid communication with the water absorption vessel gas outlet, a gas outlet for dried gas, and a liquid outlet.
In some embodiments, a method of separating moisture from a gas comprises contacting the gas with a microemulsion to absorb water from the gas into the microemulsion, producing dehumidified gas and used microemulsion. Microemulsion carried over in the dehumidified gas is separated from the dehumidified gas with a gas-liquid phase separator to produce dried gas. In some optional embodiments, the used microemulsion is heated to form a modified used microemulsion and non-emulsified water, and the non-emulsified water is separated to form a regenerated microemulsion, which is recycled for contact with the gas.
In any of the foregoing embodiments, the phase separator comprises a centrifugal phase separator.
In any of the foregoing embodiments, the phase separator comprises a liquid droplet capture medium.
In any of the foregoing embodiments, the liquid droplet capture medium comprises a mesh pad with a mesh size of 0.1 μm to 10 μm.
In any of the foregoing embodiments, the liquid droplet capture medium comprises a plurality of mesh pads separated by barrier layers.
In any of the foregoing embodiments, the phase separator comprises a liquid micro-droplet coalescing medium.
In any of the foregoing embodiments, the liquid micro-droplet coalescing medium comprises a micro-fiber filter medium with a mesh size of 0.1 μm to 10 μm.
In any of the foregoing embodiments, the phase separator comprises a centrifugal phase separator, a liquid droplet capture medium, and a liquid micro-droplet coalescing medium.
In any of the foregoing embodiments, pressure at the gas outlet of the gas-liquid phase separator differs from pressure at the inlet of the gas-liquid phase separator by less than or equal to 50% of the pressure at the inlet of the gas-liquid phase separator.
In any of the foregoing embodiments, pressure at the gas outlet of the gas-liquid phase separator differs from pressure at the inlet of the gas-liquid phase separator by less than or equal to 10% of the pressure at the inlet of the gas-liquid phase separator.
In any of the foregoing embodiments, pressure at the gas outlet of the gas-liquid phase separator differs from pressure at the inlet of the gas-liquid phase separator by less than or equal to 2% of the pressure at the inlet of the gas-liquid phase separator.
In any of the foregoing embodiments, the system further comprises a used microemulsion heat exchanger comprising a heat absorption side inlet in fluid communication with a water absorption vessel liquid outlet, and a heat absorption side outlet. The system also includes a water desorption vessel comprising an inlet in fluid communication with the used microemulsion heat exchanger heat absorption side outlet, a water outlet, and a microemulsion outlet. The system also includes a microemulsion regenerator for thermal regeneration of microemulsion from the water desorption vessel. The microemulsion regenerator comprises a regenerator inlet in fluid communication with the water desorption vessel microemulsion outlet, and a regenerator outlet in fluid communication with a water absorption vessel microemulsion inlet.
In any of the foregoing embodiments, the system further comprises a microemulsion recycle stream for a portion of the regenerated microemulsion from the microemulsion regenerator outlet to the microemulsion heat absorption side inlet.
In any of the foregoing embodiments, the system further comprises a regenerated microemulsion heat exchanger comprising a heat rejection side inlet in fluid communication with the microemulsion regenerator outlet and a heat rejection side outlet in fluid communication with the water absorption vessel microemulsion inlet.
In any of the foregoing embodiments, the gas comprising moisture to be removed is outside air, and the gas outlet of the gas-liquid phase separator is in fluid communication with a conditioned space.
In any of the foregoing embodiments, the system further comprises a vapor compression cooling system comprising a refrigerant in thermal communication with the conditioned space. In some embodiments, the refrigerant is also in thermal communication with the microemulsion.
In some embodiments of this disclosure, an air conditioning system comprises a water absorption vessel comprising a microemulsion disposed therein. The water absorption vessel also comprises an air inlet in fluid communication with a source of air to be conditioned, a microemulsion inlet, a gas outlet, and a liquid outlet. The system includes a heat exchanger for used microemulsion from the water absorption vessel. The heat exchanger for used microemulsion comprises a heat absorption side inlet in fluid communication with the water absorption vessel liquid outlet and a heat absorption side outlet. The system also includes a water desorption vessel. The water desorption comprises an inlet in fluid communication with the microemulsion heat exchanger heat absorption side outlet, a water outlet, and a microemulsion outlet. The system also includes a microemulsion regenerator for thermal regeneration of microemulsion from the water desorption vessel. The microemulsion regenerator comprises a regenerator inlet in fluid communication with the water desorption vessel microemulsion outlet, and a regenerator outlet in fluid communication with the water absorption vessel microemulsion inlet. The system also includes a vapor compression cooling system comprising a refrigerant in thermal communication with the conditioned space, wherein the refrigerant is also in thermal communication with the microemulsion. In some embodiments, the air conditioning system optionally further a comprises a regenerated microemulsion heat exchanger comprising a heat rejection side inlet in fluid communication with the microemulsion regenerator outlet and a heat rejection side outlet in fluid communication with the water absorption vessel microemulsion inlet, wherein the vapor compression heat transfer system comprises an evaporator as a heat absorption side of the regenerated microemulsion heat exchanger.
In any of the foregoing embodiments, the vapor compression heat transfer system can comprise a condenser as a heat rejection side of the used microemulsion heat exchanger.
In any of the foregoing embodiments, the vapor compression heat transfer system can comprise an evaporator as a cooling source for the microemulsion regenerator.
In any of the foregoing embodiments, a heat exchanger of the vapor compression heat transfer system comprises a heat rejection side inlet in fluid communication with the conditioned air from the phase separator gas outlet, and a heat rejection side outlet in fluid communication with the conditioned space.
In any of the foregoing embodiments, cooled air from the vapor compression heat transfer system is mixed with the conditioned air from the phase separator gas outlet and provided to the conditioned space.
Subject matter of this disclosure is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
It has been discovered that the energy and system component requirements on VCC systems for excess cooling to handle the latent cooling load and then reheat the air being conditioned can create inefficiency in the air conditioning process and system. Additionally, water condensation on metallic heat exchanger coils can cause corrosion problems, further adding to system design and fabrication costs as well as requiring additional system. Alternate humidity removal approaches such as desiccant wheels loaded with a solid desiccant positioned downstream of a temperature control unit can be space-consuming, and significant thermal energy is typically required to regenerate the desiccant, leading to efficiency reductions. Moreover, because the desiccant wheel is relatively cumbersome and not easy to install or uninstall, the capacity and operation of the systems based on desiccant wheels are generally not modular enough to accommodate a wide range of operations. Liquid desiccant systems can avoid some of the physical configuration limitations imposed by solid desiccant systems by providing the capability to move the liquid desiccant through a flow loop. However, liquid desiccants (e.g., lithium chloride) can be highly corrosive or toxic, or both, further adding to system design complexity, system cost, and fabrication costs as well as requiring additional system maintenance. Also, as with solid desiccants, significant heat energy is typically required to regenerate the desiccant, reducing system efficiency.
With reference now to
The microemulsion can comprise inverse micelles of an amphiphilic surfactant in a non-polar non-volatile organic compound such as an oil (including oil blends). In some embodiments, the oil has a boiling point greater than about 100° C. at 100 kPa. In some embodiments, at least 70% of the atoms in the oil's molecular structure are carbon or hydrogen. In some embodiments, the oil can comprise at least one polyalphaolefin. When the surfactant concentration in the oil/surfactant mixture exceeds the critical micelle concentration (“CMC”), the surfactant molecules form inverse micelles via spontaneous self-assembly in the oil. The CMC can be defined as the concentration of surfactants above which micelles or inverse micelles form. The CMC can be determined by measuring the surface tension of the oil/surfactant mixture. At surfactant concentration levels below the CMC, the surface tension varies with surfactant concentration. At surfactant concentration levels above the CMC, the surface tension exhibits small to no levels of change with surfactant concentration. Small angle neutron scattering can also be used to measure the configuration or structure of micelles in the liquid to determine whether the CMC has been reached. The precise value of the CMC can vary with temperature, pressure, and the presence and concentration of other surface active substances. For example, the value of CMC for sodium dodecyl sulfate in water at 25° C. and atmospheric pressure is 0.008 moles/liter in the absence of other additives or salts.
Amphiphilic surfactants include hydrophobic and hydrophilic groups disposed on separate portions of a molecule, such as on opposite ends of the molecule. In certain embodiments, the at least one surfactant may comprise at least one of organosulfate salts, sulfonate salts or anhydride amino esters. In some embodiments, the at least one surfactant can comprise at least one of organosulfate salts, sulfonate salts or anhydride amino esters. Examples of surfactant include but are not limited to sodium dodecyl sulfate or dioctyl sodium sulfosuccinate. In the microemulsion, the hydrophobic group of the surfactant molecule is disposed outwardly with respect to the micelle, in contact with the surrounding oil. The hydrophilic group of the surfactant molecule is disposed inwardly with respect to the micelle. The hydrophilic groups of the surfactant molecule have a physiochemical affinity for water molecules, and can therefore adsorb water vapor into the inner surface of the inverse micelle, sequestering the water within each inverse micelle.
With continued reference to
In some embodiments, the phase separator 42 can include a liquid droplet capture medium. In some embodiments, the liquid droplet capture medium can be a stand-alone phase separator. In some embodiments, the liquid droplet capture medium can be disposed in a separate device in series downstream from a centrifugal phase separator to capture smaller droplets (e.g., sized in the 10 μm to 100 μm range, but optionally including capture of droplets smaller than those captured by the centrifugal separator 230 (
In some embodiments, the phase separator 42 can include a liquid micro-droplet coalescing medium. In some embodiments, the liquid micro-droplet coalescing medium can be a stand-alone phase separator (i.e., a coalescer). In some embodiments, the liquid droplet capture medium can be disposed in a separate device (i.e., a coalesce) in series downstream from a centrifugal phase separator and a liquid droplet capture medium to coalesce even smaller droplets (e.g., sized in the 10 μm to 100 μm range, but optionally including capture of droplets smaller than those captured by the phase separator 300 (
In some embodiments, multiple types of phase separation technologies can be combined into a single device. An example of such an embodiment is schematically depicted in
In some embodiments, the water absorption vessel 14 (
From water desorption vessel 28, the mixture of oil and surfactant pass through conduit 32 to microemulsion regenerator 34, where the mixture is cooled (e.g., to a temperature of at 50° C. to 60° C.) to spontaneously regenerate the inverse micelles of the microemulsion. Any device capable of cooling the mixture to regenerate the microemulsion (e.g., a chiller or heat rejection side of a heat exchanger) can serve as the microemulsion regenerator 34. A portion of the regenerated microemulsion (e.g., 15-20 wt. %) can optionally be recycled to the inlet of heat exchanger 26 through conduit 35 to enhance separation of water from the used microemulsion in water desorption vessel 28. In some embodiments, the regenerated microemulsion can be further cooled in regenerated microemulsion heat exchanger 36 before returning through conduit 38 to the water absorption vessel 14.
In some embodiments, a microemulsion-based moisture/gas separation system such as an air conditioning system (either with or without a gas-liquid phase separator) can be integrated with a vapor compression cooling (VCC) system such as a system comprising a compressor, a condenser, an expansion device, and an evaporator, connected together by a refrigerant flow loop. In some such embodiments, a microemulsion-based air conditioning system provides dehumidification of air and takes on latent cooling loads, while sensible cooling is provided the VCC system in thermal communication with the conditioned space. Although it is not required or necessarily achieved in all embodiments, in some embodiments, this can provide the technical effect of avoiding or reducing the need for supercooling and reheating of conditioned air by the VCC system and provide increased overall system efficiency. For example, in the example embodiment depicted in
Other examples of embodiments of air conditioning systems are schematically depicted in
In some embodiments, a VCC system can be integrated with its refrigerant in thermal communication with the microemulsion loop of the system 10 to deliver or remove heat from the microemulsion loop, which can promote system energy efficiency. An example of an embodiment of an integrated heat transfer system with a refrigerant circulation loop is shown in block diagram form in
Typically, the condenser 54 is disposed outdoors with heat rejected to the ambient environment, and the evaporator 58 is disposed indoors so that heat is absorbed from a conditioned space. In the embodiment shown in
It should be noted that the various vessels, components, structures, and functions disclosed herein as discrete vessels, components or structures, and functions can be integrated together within the scope of this disclosure. For example, the used microemulsion heat exchanger 26 and the water desorption vessel 28 are depicted in
While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the present disclosure. Additionally, while various embodiments of the present disclosure have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments. Accordingly, the present disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US2017/014889 | 1/25/2017 | WO | 00 |
Number | Date | Country | |
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62288282 | Jan 2016 | US |