DESORBER FOR AIR CONDITIONING SYSTEM HAVING INTEGRATED MICROEMULSION-BASED AIR DEHUMIDIFICATION

Disclosed is a desorber (20) for an air conditioning system with an integrated microemulsion-based air dehumidification system, the desorber having: a desorbing sheet that is wound to form an exterior end (21), an interior end (22), a top end and bottom end, wherein a collection tube (23) is disposed at the interior end and the desorbing sheet has: a plurality of de-entrainment mesh layers extending between the exterior end and the interior end of the desorbing sheet, and a plurality of substantially air impermeable connector layers extending between the exterior end and the interior end of the desorbing sheet, wherein the connector layers are interlaid with the mesh layers between the top end and the bottom end of the desorbing sheet.

BACKGROUND

Exemplary embodiments pertain to the art of desorbing systems and more specifically to a desorber for an air conditioning system having integrated microemulsion-based air dehumidification.

One type of air conditioning system is a heating ventilation air conditioning (HVAC) system with an integrated microemulsion-based air dehumidification system is a technology that may provide latent air cooling while enhancing system performance. A microemulsion-based air dehumidification system may present an efficient and cost-effective alternative to dehumidification technologies involving corrosive liquid desiccant solutions (LiCl, LiBr) and desiccant wheels. A microemulsion-based air dehumidification system may be enabled by organic liquid-based microemulsion sorbents which may provide the following relative benefits: 1) heat required for microemulsion organic liquid regeneration e.g. via a microemulsion-based desorber may be a fraction of that required when using other desiccants; 2) desiccant regeneration temperature may be comparably low; 3) when heat is supplied, absorbed fluids may be released as liquid rather than vapor thereby reducing the need for certain condensers while desorbed fluids may be used to cool other condensers; and 4) the utilized organic solutions are not corrosive thereby reducing operational complexity and cost.

In view of the benefits of an HVAC system using a microemulsion-based air dehumidification system, there is a desire to address oil carryover downstream of a microemulsion-based desorber. Two categories of oil carryover include: (1) carryover in a form of an aerosol (liquid droplets); and (2) carryover in a form of a vapor. Oil droplets may occur from airflow velocity profiles created by geometrical features of oil wetted surfaces. Oil vapor may occur from temperature of the process vis-à-vis the oil vapor pressure. Typical processes for capturing oil aerosols may involve impacting and coalescing oil droplets onto a high surface area organic or metal fiber mesh. Processes for capturing oil vapors may involve refrigeration or/and adsorption of the oil vapor using a high-capacity solid sorbent.

Industrial devices may experience oil carryover issues including for example oil-lubricated rotary screw air compressors. Devices that address oil carryover may be designed for systems which produce large quantities of oil carryover compared with an HVAC system and may be designed for continuous removal of captured oil droplets, which can result in energy waste.FIGS. 1A and 1Billustrate known industrial desorbers10a,10bhaving automated drains. Such systems may be very complex and costly. In addition, such systems may be designed for operations that involve relatively high pressures providing oversized components that allow for an undesirably high pressure drop.

BRIEF DESCRIPTION

Disclosed is a desorber for an air conditioning system with an integrated microemulsion-based air dehumidification system, the desorber comprising: a desorbing sheet that is wound to form an exterior end, an interior end, a top end and bottom end, wherein a collection tube is disposed at the interior end and the desorbing sheet comprises: a plurality of de-entrainment mesh layers extending between the exterior end and the interior end of the desorbing sheet, and a plurality of substantially air impermeable connector layers extending between the exterior end and the interior end of the desorbing sheet, wherein the connector layers are interlaid with the mesh layers between the top end and the bottom end of the desorbing sheet.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the connector layers are interlaid with the mesh layers the in a stripe pattern.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the desorbing sheet is spirally wound.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that a radially center collection tube.

In addition to one or more of the features described above, or as an alternative, further embodiments may include the collection tube comprises an inner vapor filter and/or the desorbing sheet is wrapped in an outer vapor filter.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that each vapor filter is an activated carbon filter.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that top and bottom layers of the desorbing sheet are connector layers.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the mesh layers and/or connector layers are substantially dimensionally alike.

Further disclosed is an air conditioning system with an integrated microemulsion-based air dehumidification system, the microemulsion-based air dehumidification system including a desorber having one or more of the above features. Additionally disclosed is a method of desorbing oil from oil impregnated air in an air conditioning system with integrated microemulsion-based air dehumidification system, the method comprising: channeling the air into a desorber, the desorber having one or more of the above features.

DETAILED DESCRIPTION

FIGS. 5A-5Billustrate a desorber20, according to an embodiment for a microemulsion-based dehumidification system that is part of an air conditioning system, e.g., a heating venting air conditioning (HVAC) system and/or a refrigeration system. The desorber20may provide advantages typically found in a more complex system. The desorber20may be in the form of a replaceable module or cartridge, have a relatively small footprint and provide a relatively low pressure drop.

Referring now toFIGS. 2, 5A and 5B, the desorber20may minimize aerosol concentration of oil in part by functioning as a centrifugal separator30. The centrifugal separator30may include a housing32with a plurality of openings, including first opening34a, second opening34band third opening34c. The first opening34afunctions as an inlet for oil impregnated air, and the second opening34bfunctions as an outlet for partially desorbed air. The third opening34cfunctions as a drain for oil collected in the separator30. A centrifugal separator30forces incoming air into a spiral flow, which drives the larger and heavier droplets toward the walls of the housing32to be separated out by gravity.

Similarly, as illustrated inFIG. 5B, the disclosed desorber20has a spiral wound configuration, e.g., in a top view thereof, to form a centrifugal separator. The spiral curve of the desorber20is illustrated as planar and more specifically as an Archimedean spiral or involute of a circle. Other two dimensional spirals and three dimensional spirals may be applicable. Oil impregnated airflow enters in the outer radial segment21of the desorber20and speeds up while traveling to the center22of the desorber20into an oil collection tube23. Larger, heavier droplets are centrifugally driven outward.

Referring now toFIGS. 3A, 3B, 5A and 5B, smaller aerosol particles in oil impregnated air may not be removed with centrifugal motion because smaller particles follow air streamlines. A known centrifugal separator30may therefore be fluidly followed by a known demister40. The demister40includes a demister housing42, a demister inlet44acarrying oil impregnated air, a demister vapor outlet46carrying oil vapor demisted from the oil impregnated air, a demisted air outlet48carrying demisted air. The demister40may also include a pressure release loop50fluidly connected to the demisted air outlet48. Internally, the demister40may contain a diffuser52and one or more mesh pads54, illustrated in greater detail inFIG. 3B. The mesh pads54capture smaller oil droplets by impaction.

Similarly, the disclosed embodiment inFIGS. 5A and 5Bmay provide a plurality of layers of de-entrainment mesh material, including layers24a-24d. The mesh layers24a-24bmay be spaced along a top-down direction for the desorber20, i.e., from the top end25of the desorber20to the bottom end26of the desorber20. The mesh layers24a-24dmay extend along the direction of airflow, so that each layer is extends between the radial outside of the desorber21and the radial inside of the desorber22. The top-down span or height of the layers of mesh material24a-24dare illustrated as each being substantially the same, though this is not a requirement. The area of each of the mesh layers24a-24d, and the area summation of the layers, may be sufficient to demist air traveling through the desorber20. The mesh layers24a-24dmay be plastic.

Turning now toFIGS. 4, 5A and 5B, the impregnated air in a known desorber may pass over coalescing membranes62,64. The membranes62,64may coalesce remaining oil droplets into larger drops, which drain by gravity. In the disclosed embodiment, illustrated inFIGS. 5A and 5B, as impregnated air travels through the desorber20, the shape of the mesh layers24a-24dprovides a large area for impaction and oil droplets coalesce as oil collides with the mesh surfaces and eventually drains downwards. For less demanding applications, such as with microemulsion-based dehumidification systems, the flow path could include a helically shaped desorber providing a continuous change of directional flow. Such shape can obtained with a 3D curve (not illustrated) rather than a spiral 2D curve.

A plurality of connector layers27a-27eare interlaid with the mesh layers24a-24dbetween the top end and the bottom end of the desorbing sheet. The connector layers27a-27eare substantially air impermeable and extend between the internal end21and the internal end22of the desorber20. The plurality of connector layers27a-27eare, e.g., plastic. Other spacer material may be utilized for the connector layers.

Turning now toFIGS. 5A, 5B and 6, an outer filter72may be used as a fourth desorbing element for processes where oil vapors in addition to oil aerosols are not tolerated. In a known desorbing system a refrigerant dryer (not illustrated) may be utilized or an activated carbon cartridge such as found within certain drinking bottles74may be wrapped around the desorber20to form the outer filter72. Similarly, the disclosed embodiment may provide an inner vapor filter which is an active carbon filter cartridge28at the inner radius22of the desorber20. The specific diameter and length of the active carbon cartridge28may be sufficient to provide desired filtering of oil vapor in air traveling therethrough.

For microemulsion-based dehumidification systems, the use of four separate devices described above results in excessive cost and pressure drop. The above disclosed desorber20may provide a relatively compact system designed to accomplish the same goal of more complex systems by combining the actions of centrifugal motion, impaction and coalescing.

In sum as illustrated inFIG. 5Bthe packaging of the desorber20may be a spiral-wound sheet. The desorber20comprises one or more membrane envelopes, wrapped around the central oil collection tube23, and the tube23may surrounded by the active carbon cartridge28. The permeating air travels toward the oil collection tube23along the spiral path with minimum pressure drop.