Patent Description:
Embodiments of the present disclosure generally relate to a liquid panel assembly, and more particularly, to a liquid panel assembly configured for use with an energy exchanger.

Enclosed structures, such as occupied building, factories and the like, generally include a heating/ventilation/air conditioning (HVAC) system for conditioning outdoor ventilated and/or recirculated air. The HVAC system includes a supply air flow path and an exhaust air flow path. The supply air flow path receives pre-conditioned air, for example outside air or outside air mixed with re-circulated air, and channels and distributes the pre-conditioned air into the enclosed structure. The pre-conditioned air is conditioned by the HVAC system to provide a desired temperature and humidity of supply air discharged into the enclosed structure. The exhaust air flow path discharges air back to the environment outside the structure. Without energy recovery, conditioning the supply air typically requires a significant amount of auxiliary energy, particularly in environments having extreme outside air conditions that are much different than the required supply air temperature and humidity. Accordingly, energy exchange or recovery systems are used to recover energy from the exhaust air flow path. Energy recovered from air in the exhaust flow path is utilized to reduce the energy required to condition the supply air.

Conventional energy exchange systems may utilize energy recovery devices (for example, energy wheels and permeable plate exchangers) or heat exchange devices (for example, heat wheels, plate exchangers, heat-pipe exchangers and run- around heat exchangers) positioned in both the supply air flow path and the return air flow path. Liquid-to-air membrane energy exchangers (LAMEEs) may be fluidly coupled so that a desiccant liquid flows between the LAMEEs in a run-around loop, similar to run-around heat exchangers that typically use aqueous glycol as a coupling fluid.

Prior art documents <CIT> and <CIT> both disclose heat exchanger systems having a series of liquid panel assemblies according to the preamble of claim <NUM> having multiple flow paths therein.

In general, a LAMEE transfers heat and moisture between a liquid desiccant solution and air through a thin flexible membrane. A flat plate LAMEE includes a series of alternating liquid desiccant and air channels separated by the membrane. Typically, the pressure of the liquid within a liquid channel between membranes is higher than that of the air pressure outside of the membranes. As such, the flexible membranes tend to outwardly bow or bulge into the air channel(s).

In order to avoid excessive restriction of the air flow due to membrane bulge, air channels of a LAMEE are relatively wide compared to the liquid channels. Moreover, a support structure is generally provided between membranes to limit the amount of membrane bulge. However, the relatively wide air channels and support structures typically diminish the performance of the LAMEE. In short, resistance to heat and moisture transfer in the air channel is relatively high due to the large air channel width, and the support structure may block a significant amount of membrane transfer area. Accordingly, a large amount of membrane area is needed to meet performance objectives, which adds costs and results in a larger LAMEE. Moreover, the support structure within an air channel may produce an excessive pressure drop, which also adversely affects operating performance and efficiency of the LAMEE.

Typically, desiccant flows through a solution panel, which may include membranes that contain the desiccant between air channels. In general, the solution panel is uniformly full of desiccant during operation. Known energy exchangers force flow of desiccant upwardly through the solution panel, against the force of gravity. As such, the desiccant is typically pumped from the bottom of the solution panel to the top with enough pressure to overcome the relatively large amount of static head pressure, as well as the friction in the panel. However, the pumping pressure causes the membranes of the solution panel to outwardly bow or bulge. Moreover, the pumping pressure is often great enough to cause leaks in the membranes. Further, the pressure of the desiccant being pumped through the solution panel often causes membrane creep and degradation over time.

A typical solution panel also includes a filler material, such as a wick or woven plastic screen, configured to ensure proper spacing between membrane surfaces within the solution panel. The flow of the desiccant through the filler material is generally uncontrolled. For example, the filler material is generally unable to direct the desiccant over a particular path. Instead, the flow of desiccant through the filler material follows the path of least resistance, which generally follows a Hele-Shaw pattern between closed-spaced plates. Further, the flow pattern of the desiccant is sensitive to variations in the spacing within the solution panel caused by even small amounts of membrane bulge. Also, fluid instabilities from concentration and temperature gradients may cause additional flow irregularities and mal-distributions. The winding flow pattern within a typical solution panel produces flow dead zones at or proximate corners of the solution panel.

As noted, in order to ensure that desiccant completely fills the solution panel from bottom to top, a relatively high pumping pressure is used. However, the pumping pressure may often generate membrane bulge and bowing, which may adversely affect the energy exchanger.

Certain embodiments of the present disclosure provide a liquid panel assembly, which may be configured to be used with an energy exchanger, for example. The liquid panel assembly may include a support frame having one or more fluid circuits and at least one membrane secured to the support frame. Each fluid circuit may include an inlet channel connected to an outlet channel through one or more flow passages, such as counterflow passages (in that liquid in the counterflow passages counterflows with respect to another fluid, such as air, outside of the at least one membrane). A liquid, such as a desiccant, is configured to flow through the fluid circuit(s) and contact interior surfaces of the membrane(s). The fluid circuit(s) is configured to offset hydrostatic pressure gain with friction pressure loss of the liquid that flows within the one or more fluid circuits to reduce pressure within the liquid panel assembly.

The shape, porosity, and/or hydraulic diameter of one or both of the inlet and outlet channels may be determined by a weight, viscosity, and/or flow speed of the liquid that is configured to flow through the fluid circuit(s). For example, if the liquid is heavy, the diameters of the channels may be reduced in order to promote faster liquid flow therethrough, which generates increased friction that offsets the liquid hydrostatic pressure.

The flow passages may include a set of a plurality of flow passages connected to the inlet channel and the outlet channel. A number of flow passages within the set of a plurality of flow passages may be determined by a weight and/or viscosity of the liquid that is configured to flow through the fluid circuit(s).

The fluid circuit(s) may include a plurality of fluid circuits. The lengths of each of the fluid circuits may be equal. The plurality of fluid circuits may include a first set of a plurality of flow passages connected to a first inlet channel and a first outlet channel, and a second set of a plurality of flow passages connected to a second inlet channel and a second outlet channel. The first set of a plurality of flow passages may be staggered with respect to the second set of a plurality of flow passages. Each of the inlet and outlet channels may provide a flow alignment vane configured to direct the liquid to flow along a particular path. The inlet and outlet channels may be configured to provide support to the membrane(s). The inlet and outlet channels may be configured to provide a sealing surface for at least a portion of the membrane(s). The inlet and outlet channels may be configured to maximize a length of the flow passages.

Each of the inlet and outlet channels may provide a flow alignment vane configured to direct the liquid to flow along a particular path. The inlet and outlet channels may be configured to provide support to the membrane(s). The inlet and outlet channels may be configured to provide a sealing surface for at least a portion of the membrane(s). The inlet and outlet channels may be configured to maximize a length of the flow passages.

The membrane(s) may be continuously bonded around a perimeter of the support frame. The fluid circuits may be configured to provide uniform liquid flow distribution across and/or through the liquid panel assembly. The support frame and the membrane may be configured to be vertically oriented within an energy exchange cavity of an energy exchanger.

The inlet channel may be disposed at an upper corner of the support frame. The outlet channel may be disposed at a lower corner of the support frame. The upper corner may be diagonally located from the lower corner. The inlet and outlet channels may be vertical and the flow passages(s) may be horizontal. A horizontal length of the flow passage(s) may exceed half a total horizontal length of the support frame. The assembly may also include inlet and outlet members, such as headers, connected to the fluid circuit(s). The inlet and outlet members may include a liquid delivery channel and a liquid passage channel, respectively. The inlet member may be configured to modularly engage another inlet member, and the outlet member may be configured to modularly engage another outlet member. At least a portion of the membrane(s) may sealingly engage the inlet and outlet members.

Alternatively, the support frame and the membrane may be configured to be horizontally oriented within an energy exchange cavity of an energy exchanger.

The inlet channel may be disposed at one corner of the support frame. The outlet channel may be disposed at another corner of the support frame. The first corner may be diagonally located from the second corner. The inlet and outlet channels may be vertical and the flow passages(s) may be horizontal. A horizontal length of the flow passage(s) may exceed half a total horizontal length of the support frame.

The assembly may also include inlet and outlet members, such as headers, connected to the fluid circuit(s). The inlet member may fluidly engage all inlet channels and the outlet member may fluidly engage all outlet channels.

Alternatively, the flow passages in one or more panels can be fluidly connected to members, such as headers. One or more of these members can be fluidly connected to flow channels. Inlet channels can be fluidly connected to inlet members which can, in turn, be connected to flow passages. The flow passages can be fluidly connected to outlet members, such as headers, which are, in turn, connected to outlet channels.

Certain embodiments of the present disclosure provide an energy exchange system that may include a plurality of air channels configured to allow air to pass therethrough, and a plurality of liquid panel assemblies alternately spaced with the plurality of liquid panel assemblies. The system may also include a plurality of membrane support assemblies disposed within the plurality of air channels. Air within the air channels may be configured to counterflow with respect to the liquid within the one or more flow passages.

The foregoing summary, as well as the following detailed description of certain embodiments will be better understood when read in conjunction with the appended drawings. Furthermore, references to "one embodiment" are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments "comprising" or "having" an element or a plurality of elements having a particular property may include additional such elements not having that property.

As explained in detail below, embodiments of the present disclosure provide liquid panel assemblies that are configured to balance internal liquid hydrostatic pressure and frictional forces. As such, the total pressure within the liquid panel assemblies may be reduced, negated or otherwise neutralized. Embodiments of the present disclosure provide a liquid panel assembly that may be configured, through selection of a number, orientation, shape, and/or the like of flow channels or passages, to ensure that pressure within the assembly is substantially reduced, negated, or otherwise neutralized. That is, the pressure may be reduced, negated, or otherwise neutralized to a greater extent than a negligible amount. Thus, membrane bulge is substantially reduced (that is, more than a negligible amount) or eliminated, which reduces the potential for leaks and membrane creep.

<FIG> illustrates a schematic view of an energy exchange system <NUM>, according to an embodiment of the present disclosure. The system <NUM> is configured to partly or fully condition air supplied to a structure <NUM>. The system <NUM> may include an inlet <NUM> for a pre-conditioned air flow path <NUM>. The pre-conditioned air flow path <NUM> may include outside air, air from a building adjacent to the enclosed structure <NUM>, or air from a room within the enclosed structure <NUM>. Airflow in the pre-conditioned air flow path <NUM> may be moved through the pre-conditioned air flow path <NUM> by a fan <NUM>. The fan <NUM> directs the pre-conditioned air flow through path <NUM> to a supply air liquid- to-air membrane energy exchanger (LAMEE) <NUM>. The supply air LAMEE <NUM> conditions the pre-conditioned air flow in path <NUM> to generate a change in air temperature and humidity (i.e. to pre-conditioned the air partly or fully) toward that which is required for a supply air flow condition to be discharged into the enclosed space <NUM>. During a winter mode operation, the supply air LAMEE <NUM> may condition the preconditioned air flow path <NUM> by adding heat and moisture to the pre-conditioned air in flow path <NUM>. In a summer mode operation, the supply air LAMEE <NUM> may condition the pre-conditioned air flow path <NUM> by removing heat and moisture from the preconditioned air in flow path <NUM>. The pre-conditioned air <NUM> may be channeled to an HVAC system <NUM><NUM> of the enclosed structure <NUM>. The HVAC system <NUM><NUM> may further condition the pre-conditioned air <NUM><NUM> to generate the desired temperature and humidity for the supply air <NUM> that is supplied to the enclosed structure <NUM>.

As shown in <FIG>, one fan <NUM> may be located upstream of the LAMEE <NUM>. Optionally, the pre-conditioned air flow path <NUM> may be moved by a down-stream fan and/or by multiple fans or a fan array or before and after each LAMEE in the system.

Return air <NUM> is channeled out of the enclosed structure <NUM>. A mass flow rate portion <NUM> of the return air <NUM> may be returned to the HVAC system <NUM>. Another mass flow rate portion <NUM><NUM> of the return air <NUM> may be channeled to a return air or regeneration LAMEE <NUM>. The portions <NUM> and <NUM> may be separated with a damper <NUM> or the like. For example, <NUM>% of the return air <NUM> may be channeled to the HVAC system <NUM><NUM> and <NUM>% of the return air <NUM> may be channeled to the return air LAMEE <NUM>. The return air LAMEE <NUM> exchanges energy between the portion <NUM> of the return air <NUM><NUM> and the preconditioned air <NUM><NUM> in the supply air LAMEE <NUM>. During a winter mode, the return air LAMEE <NUM> collects heat and moisture from the portion <NUM><NUM> of the return air <NUM><NUM>. During a summer mode, the return air LAMEE <NUM> discharges heat and moisture into the portion <NUM><NUM> of the return air <NUM><NUM>. The return air LAMEE <NUM> generates exhaust air <NUM>. The exhaust air <NUM> is discharged from the structure <NUM> through an outlet <NUM>. A fan <NUM> may be provided to move the exhaust air <NUM> from the return air LAMEE <NUM>. The system <NUM> may include multiple fans <NUM> or one or more fan arrays located either up-stream or down-stream (as in <FIG>) of the return air LAMEE <NUM>.

A liquid, such as a desiccant fluid <NUM>, flows between the supply air LAMEE <NUM> and the return air LAMEE <NUM>. The desiccant fluid <NUM> transfers the heat and moisture between the supply air LAMEE <NUM> and the return air LAMEE <NUM>. The system <NUM> may include desiccant storage tanks <NUM> in fluid communication between the supply air LAMEE <NUM> and the return air LAMEE <NUM>. The storage tanks <NUM> store the desiccant fluid <NUM> as it is channeled between the supply air LAMEE <NUM> and the return air LAMEE <NUM>. Optionally, the system <NUM> may not include both storage tanks <NUM> or may have more than two storage tanks. Pumps <NUM> are provided to move the desiccant fluid <NUM> from the storage tanks <NUM> to one of the supply air LAMEE <NUM> or the return air LAMEE <NUM>. The illustrated embodiment includes two pumps <NUM>. Optionally, the system <NUM> may be configured with as few as one pump <NUM> or more than two pumps <NUM>. The desiccant fluid <NUM> flows between the supply air LAMEE <NUM> and the return air LAMEE <NUM> to transfer heat and moisture between the conditioned air <NUM> and the portion <NUM> of the return air <NUM>.

<FIG> illustrates a side perspective view of a LAMEE <NUM>, according to an embodiment. The LAMEE <NUM> may be used as the supply air LAMEE <NUM> and/or the return or exhaust air LAMEE <NUM> (shown in <FIG>). The LAMEE <NUM> includes a housing <NUM> having a body <NUM>. The body <NUM> includes an air inlet end <NUM> and an air outlet end <NUM>. A top <NUM> extends between the air inlet end <NUM> and the air outlet end <NUM>. While note shown, a stepped-down top may be positioned at the air inlet end <NUM>. The stepped-down top may be stepped a distance from the top <NUM>. A bottom <NUM> extends between the air inlet end <NUM> and the air outlet end <NUM>. While not shown, a stepped-up bottom may be positioned at the air outlet end <NUM>. The stepped-up bottom may be stepped a distance from the bottom <NUM>. In alternative designs the stepped-up bottom or stepped-down top sections may have different sizes of steps or no step at all.

An air inlet <NUM> is positioned at the air inlet end <NUM>. An air outlet <NUM> is positioned at the air outlet end <NUM>. Sides <NUM> extend between the air inlet <NUM> and the air outlet <NUM>.

An energy exchange cavity <NUM> extends through the housing <NUM> of the LAMEE <NUM>. The energy exchange cavity <NUM> extends from the air inlet end <NUM> to the air outlet end <NUM>. An air stream <NUM> is received in the air inlet <NUM> and flows through the energy exchange cavity <NUM>. The air stream <NUM> is discharged from the energy exchange cavity <NUM> at the air outlet <NUM>. The energy exchange cavity <NUM> may include a plurality of panels <NUM>, such as liquid panels configured to receive desiccant and direct the flow of the desiccant therethrough.

A desiccant inlet reservoir <NUM> may be positioned on the top <NUM>. The desiccant inlet reservoir <NUM> may be configured to receive desiccant, which may be stored in a storage tank <NUM> (shown in <FIG>). The desiccant inlet reservoir <NUM> may include an inlet in flow communication with the storage tank <NUM>. The desiccant is received through the inlet. The desiccant inlet reservoir <NUM> may also include an outlet that is in fluid communication with desiccant channels <NUM> of the panels <NUM> in the energy exchange cavity <NUM>. The liquid desiccant flows through the outlet into the desiccant channels <NUM>. The desiccant flows along the panels <NUM> through the desiccant channels <NUM> to a desiccant outlet reservoir <NUM>, which may be positioned at or proximate the bottom <NUM>. Accordingly, the desiccant may flow through the LAMEE <NUM> from top to bottom. For example, the desiccant may flow into the desiccant channels <NUM> proximate the desiccant inlet reservoir <NUM>, through the desiccant channels <NUM>, and out of the LAMEE <NUM> proximate to the desiccant outlet reservoir <NUM>. In an alternative embodiment, the desiccant may flow through the LAMEE <NUM> from bottom to top.

<FIG> illustrates a cut-away front view of the panels <NUM> within the energy exchange cavity <NUM> of the LAMEE <NUM>, according to an embodiment. The panels <NUM> may be solution or liquid panels configured to direct the flow of liquid, such as desiccant, therethrough, as explained below. The panels <NUM> form a liquid desiccant flow path <NUM> that is confined by semi-permeable membranes <NUM> on either side and is configured to carry desiccant therethrough. The membranes <NUM> may or may not be porous or able to transfer mass. Each membrane <NUM> may be any flexible structure that may generally bulge under fluid pressure. The semi-permeable membranes <NUM> are arranged in parallel to form air channels <NUM> with an average flow channel width of <NUM> and liquid desiccant channels <NUM> with an average flow channel width of <NUM>. In one embodiment, the semi-permeable membranes <NUM> are spaced to form uniform air channels <NUM> and liquid desiccant channels <NUM>. The air stream <NUM> (shown in <FIG>) travels through the air channels <NUM> between the semi-permeable membranes <NUM>. The desiccant in each desiccant channel <NUM> exchanges heat and moisture with the air stream <NUM> in the air channels <NUM> through the semi-permeable membranes <NUM>. The air channels <NUM> alternate with the liquid desiccant channels <NUM>. Except for the two side panels of the energy exchange cavity, each air channel <NUM> may be positioned between adjacent liquid desiccant channels <NUM>.

In order to minimize or otherwise eliminate the liquid desiccant channels <NUM> from outwardly bulging or bowing, membrane support assemblies may be positioned within the air channels <NUM>. The membrane support assemblies are configured to support the membranes, and may promote turbulent air flow between the air channels <NUM> and the membranes <NUM>.

As an example, the LAMEE <NUM> may be similar to a LAMEE as described in <CIT>.

<FIG> illustrates an exploded isometric top view of an energy exchange cavity <NUM>, according to an embodiment. The energy exchange cavity <NUM> may include a plurality of liquid panel assemblies <NUM> spaced apart from one another by membrane support assemblies <NUM>, such as those described in <CIT>, which claims priority to <CIT>, both of which are hereby incorporated by reference in their entireties. The membrane support assemblies <NUM> may reside in air channels <NUM>. For example, the membrane support assemblies <NUM> may prevent membranes <NUM> of the solution panel assemblies <NUM> from outwardly bulging or bowing into the air channels <NUM>. Airflow <NUM> is configured to pass through the air channels <NUM> between liquid panel assemblies <NUM>. As shown, the airflow <NUM> may generally be aligned with a horizontal axis <NUM> of the energy exchange cavity <NUM>. Thus, the airflow <NUM> may be horizontal with respect to the energy exchange cavity <NUM>. Notably, however, the membrane support assemblies <NUM> may include turbulence promoters configured to generate turbulence, eddies, and the like in the airflow <NUM> within the energy exchange cavity <NUM>.

Each liquid panel assembly <NUM> may include a support frame <NUM> connected to an inlet member <NUM> at an upper corner <NUM> and an outlet member <NUM> at a lower corner <NUM> that may be diagonal to the upper corner <NUM>. Further, membranes <NUM> are positioned on each side of the support frame <NUM>. The membranes <NUM> are formed of a liquid impermeable, but air permeable, material. The membranes <NUM> sealingly engage the support frame <NUM> along outer edges in order to contain liquid within the liquid panel assembly <NUM>. Alternatively, a single membrane may sealingly wrap around an entirety of the support frame <NUM>.

Each inlet member <NUM> may include a liquid delivery opening <NUM>, while each outlet member <NUM> may include a liquid passage opening <NUM>. The liquid delivery openings <NUM> may be connected together through conduits, pipes, or the like, while the liquid passage openings <NUM> may be connected together through conduits, pipes, or the like. Optionally, the inlet members <NUM> and outlet members <NUM> may be sized and shaped to directly mate with one another so that a liquid-tight seal is formed therebetween. Accordingly, liquid, such as desiccant may flow through the liquid delivery openings <NUM> and the liquid passage openings <NUM>. The inlet members <NUM> and outlet members <NUM> may be modular components configured to selectively couple and decouple from other inlet members <NUM> and outlet members <NUM>, respectively. For example, the inlet members <NUM> and outlet members <NUM> may be configured to securely mate with other inlet members <NUM> and outlet members <NUM>, respectively, through snap and/or latching connections, or through fasteners and adhesives.

As shown, the liquid panel assemblies <NUM>, the membrane support assemblies <NUM>, and the air channels <NUM> may all be vertically oriented. The liquid panel assemblies <NUM> may be flat plate exchangers that are vertically-oriented with respect to a base that is supported by a floor, for example, of a structure.

Alternatively, the liquid panel assemblies <NUM>, the membrane support assemblies <NUM>, and the air channels <NUM> may all be horizontally oriented. For example, the liquid panel assemblies <NUM> may be flat plate exchangers that are horizontally- oriented with respect to a base that is supported by a floor, for example, of a structure.

In operation, liquid, such as desiccant, flows into the liquid delivery openings <NUM> of the inlet members <NUM>. For example, the liquid may be pumped into the liquid delivery openings <NUM> through a pump. The liquid then flows into the support frames <NUM> through a liquid path <NUM> toward the outlet members <NUM>. As shown, the liquid path <NUM> includes a vertical descent <NUM> that connects to a horizontal, flow portion, such as a flow portion <NUM>, which, in turn, connects to a vertical descent <NUM> that connects to the liquid passage opening <NUM> of the outlet member <NUM>. The vertical descents <NUM> and <NUM> may be perpendicular to the horizontal, flow portion <NUM>. As such, the liquid flows through the solution panel assemblies <NUM> from the top corners <NUM> to the lower corners <NUM>. As shown, the length of the horizontal, flow portion <NUM> substantially exceeds half the length L of the liquid panel assemblies <NUM>. The horizontal, flow portion <NUM> provides liquid, such as desiccant, that may counterflow with respect to the airflow <NUM>. Alternatively, the flow portion may be a crossflow, parallel-aligned flow, or other such flow portion, for example.

The airflow <NUM> that passes between the liquid panel assemblies <NUM> exchanges energy with the liquid flowing through the liquid panel assemblies <NUM>. The liquid may be a desiccant, refrigerant, or any other type of liquid that may be used to exchange energy with the airflow <NUM>.

The energy exchange cavity <NUM> may include more or less liquid panel assemblies <NUM>, membrane support assemblies <NUM>, and air channels <NUM> than those shown in <FIG>. The inlet and outlet members <NUM> and <NUM> may be modular panel headers that are configured to selectively attach and detach from neighboring inlet and outlet members <NUM> and <NUM> to provide a manifold for liquid to enter into and pass out of the liquid panel assemblies <NUM>. Sealing agents, such as gaskets, silicone gel, or the like, may be disposed between neighboring inlet members <NUM> and neighboring outlet members <NUM>. At least a portion of the membrane sealingly engages the inlet and outlet members <NUM> and <NUM>. The liquid panel assembly <NUM> formed in this manner provides a fully-sealed, stand-alone unit having openings at the inlet and outlet members <NUM> and <NUM>, notably the openings <NUM> and <NUM>, respectively. Accordingly, the liquid panel assembly <NUM> may be pre-tested for leaks and membrane holes prior to being positioned within an energy exchange cavity, for example.

<FIG> illustrates a front view of the support frame <NUM> of the liquid panel assembly <NUM>, according to an embodiment. For the sake of clarity, the membranes <NUM> secured to the liquid panel assembly <NUM> are not shown. However, it is to be understood that at least one membrane <NUM> is bonded to the front and back surfaces of the support frame <NUM>. For example, the membrane <NUM> may be continuously bonded around the perimeter of the support frame <NUM>, thereby creating a robust external seal.

The support frame <NUM> includes a main body <NUM> having a lower edge <NUM> connected to an upper edge <NUM> through lateral edges <NUM>. The support frame <NUM> may be formed of various materials, such as injection molded plastic, metal, or a combination thereof. The support frame <NUM> may be integrally formed and manufactured as a single piece through a single molding process, for example. For example, the inlet and outlet members <NUM> and <NUM>, respectively, may be integrally molded with the support frame <NUM>. Optionally, the support frame <NUM> may be formed as separate and distinct pieces. For example, the support frame <NUM> may be extruded and assembled from various parts.

The inlet member <NUM> includes a base <NUM> that connects to a support inlet <NUM> proximate the upper corner <NUM>. The upper corner <NUM> may include a channel configured to receive and retain the base <NUM>. For example, the base <NUM> may fit into the channel and be securely fastened therein, such as through fasteners, adhesives, or the like. Optionally, as noted above, the base <NUM> may simply be integrally formed and molded with the upper corner <NUM>. The base <NUM> supports and connects to an upper wall <NUM> through lateral walls <NUM>. The base <NUM>, the upper wall <NUM>, and the lateral walls <NUM> define the liquid-delivery opening <NUM>. Liquid passages (hidden from view in <FIG>) are formed through the base <NUM> and connect the liquid-delivery opening <NUM> to a liquid- reception area <NUM> formed at the upper corner <NUM> of the support frame <NUM>.

<FIG> illustrates an isometric top view of the inlet member <NUM>, according to an embodiment. As shown, a lower edge <NUM> of the base <NUM> may be tapered or beveled, which allows the base <NUM> to be easily mated into a reciprocal channel of the support inlet <NUM> (shown in <FIG>). An opening <NUM> is formed at a terminal end of the beveled lower edge <NUM>. The opening <NUM> connects to liquid passages (hidden from view in <FIG>) that connect to an opening (hidden from view in <FIG>) that connects to the liquid delivery opening <NUM>. Accordingly, liquid may pass from the liquid delivery opening <NUM>, out through the opening <NUM> of the base <NUM> and into the support inlet <NUM> of the support frame <NUM>.

<FIG> illustrates an internal view of the inlet member <NUM>, according to an embodiment. As shown in <FIG>, the opening <NUM> is in communication with a plurality of liquid passages <NUM> separated by guide ribs <NUM>. The liquid passages <NUM> are configured to align with liquid inlet channels of the support frame <NUM>. While eight liquid passages <NUM> are shown in <FIG>, more or less liquid passages <NUM> may be used, depending on the number of liquid inlet channels of the support frame <NUM>.

Referring again to <FIG>, the outlet member <NUM> is similarly constructed to the inlet member <NUM>. The inlet and outlet members <NUM> and <NUM> are both liquid connection members configured to deliver and/or pass liquid to and/or from the support frame <NUM>. Accordingly, similar to the inlet member <NUM>, the outlet member <NUM> includes a base <NUM> that connects to a support outlet <NUM> of the support member <NUM> proximate the lower corner <NUM>. The lower corner <NUM> may include a channel configured to receive and retain the base <NUM>. For example, the base <NUM> may fit into the channel and be securely fastened therein, such as through fasteners, adhesives, or the like. Optionally, as noted above, the base <NUM> may simply be integrally formed and molded with the lower corner <NUM>. The base <NUM> supports and connects to an upper wall <NUM> through lateral walls <NUM>. The base <NUM>, the upper wall <NUM>, and the lateral walls <NUM> define the liquid-delivery opening <NUM>. Liquid passages (hidden from view in <FIG>) are formed through the base <NUM> and connect the liquid-delivery opening <NUM> to a liquid- passage area <NUM> formed at the lower corner <NUM> of the support frame <NUM>. The outlet member <NUM> may be constructed as shown in <FIG>.

The inlet and outlet members <NUM> and <NUM> provide panel headers that are configured to provide passageways for liquid, such as desiccant, to pass into and out of the liquid panel assembly <NUM>. The inlet and outlet members <NUM> and <NUM> may also provide mating surfaces to neighboring panels to create a manifold to distribute liquid to all solution panels within an energy exchanger.

<FIG> illustrates an isometric view of an area proximate the upper corner <NUM> of the support frame <NUM> of the liquid panel assembly <NUM>. Referring to <FIG> and <FIG>, the support frame <NUM> includes vertical inlet channels <NUM> connected to vertical outlet channels <NUM> through horizontal flow passages <NUM>. As shown, the support frame <NUM> may include eight vertical inlet channels <NUM> and eight vertical outlet channels <NUM>. However, the support frame <NUM> may include more or less inlet and outlet channels <NUM> and <NUM> than those shown. Each inlet channel <NUM> may connect to five horizontal flow passages <NUM>. For example, the innermost inlet channel 490a connects to the top five horizontal flow passages 494a. Similarly, the inlet channel 490b connects to the five horizontal flow passages <NUM> below the top five horizontal flow passages 494a. Similarly, the top five flow passages 494a connect to an outermost vertical outlet channel 492a. Accordingly, the horizontal flow passages <NUM> may be staggered in sets of five with respect to the support frame <NUM>. For example, inlet ends <NUM> of the horizontal flow passages 494a are farther away from the lateral edge 444a of the support frame <NUM> than the inlet ends <NUM> of the set of horizontal flow passages <NUM> immediately below the set of horizontal flow passages 494a. However, outlet ends <NUM> of the horizontal flow passages 494a are closer to the lateral edge 444b of the support frame <NUM> than the outlet ends <NUM> of the set of horizontal flow passages <NUM> immediately below the set of horizontal flow passages 494a. Further, the length of the inlet channel 490a is shorter than the length of the inlet channel 490b adjacent the inlet channel 490a. The length of the inlet channel 490b is longer in order to connect to the set of five horizontal flow passages <NUM> underneath the set of five horizontal flow passages 494a. Conversely, the length of the vertical outlet channel 492a is longer than the length of the vertical outlet channel 492b immediately adjacent the vertical distribution channel 492a.

The vertical inlet and outlet channels <NUM> and <NUM>, respectively, provide continuous flow alignment vanes. Each channel <NUM> and <NUM> may be an isolated duct that allows the pressure of liquid in neighboring channels <NUM> and <NUM> to vary in order to evenly split the flow of liquid among the channels <NUM> and <NUM>. As noted, each vertical distribution and passage channel <NUM> and <NUM> may feed a single horizontal flow passage <NUM>, or a set or bank of horizontal flow passages <NUM>. The membrane <NUM> (shown in <FIG>) may also be bonded to internal edge surfaces of the support frame <NUM> to separate each vertical channel <NUM> and <NUM> from one another, as well as to separate each horizontal flow passage <NUM> from one another. Therefore, each fluid circuit, which includes an inlet channel <NUM>, one or more flow passages <NUM>, and an outlet channel <NUM>, may be a separate, sealed duct.

Each of the inlet and outlet channels <NUM> and <NUM> may provide a flow alignment vane configured to direct liquid to flow along a particular path. The inlet and outlet channels <NUM> and <NUM> may be configured to provide support to the membrane. The inlet and outlet channels may be configured to provide a sealing surface for at least a portion of the membrane.

As shown in <FIG>, the horizontal flow passages <NUM> are grouped in sets of five, which are staggered with respect to one another. The sets of horizontal flow passages <NUM> are staggered so that the overall length of each horizontal flow passage <NUM> is the same. Indeed, the total length of each liquid circuit, which includes a vertical inlet channel <NUM> that connects to a horizontal flow passage <NUM>, which in turn connects to a vertical outlet channel <NUM>, is the same due to the staggered nature of the sets of horizontal flow passages <NUM> and the different lengths of each of the vertical inlet channels <NUM> and the vertical outlet channels <NUM>. The total vertical height H of a liquid circuit is the length of a vertical inlet channel <NUM> plus the length of a vertical outlet channel <NUM> that connects to the vertical inlet channel <NUM> through a horizontal flow passage <NUM>. The vertical inlet channel 490a is the shortest, while the vertical outlet channel 492a (which connects to the inlet channel 490a through the fluid passages 494a) is the longest. Conversely, the vertical inlet channel 490n is the longest, while the vertical outlet channel 492n (which connects to the inlet channel 490n through the fluid passages 494n) is the shortest. Further, the length of the vertical inlet channel 490a may equal the length of the vertical outlet channel 492n, while the length of the vertical inlet channel 490n may equal the length of the vertical outlet channel 492a. In short, the total vertical lengths for each liquid circuit may sum to H. Moreover, the total length of each liquid circuit, which includes a vertical inlet channel <NUM> that connects to a vertical outlet channel <NUM> through a horizontal fluid passage <NUM>, may be equal.

While particular inlet and outlet channels <NUM> and <NUM>, respectively, are each shown connecting to a set of five horizontal fluid passages <NUM>, the inlet and outlet channels <NUM> and <NUM>, respectively, may connect to more or less than five horizontal fluid passages <NUM>. For example, the sets of horizontal fluid passages <NUM> may be two, three, six, seven, and the like. Further, each distribution and passage channel <NUM> and <NUM>, respectively, may alternatively connect to only one horizontal fluid passage <NUM>.

The liquid circuits are of equal length in order to provide for even distribution of liquid flow through the liquid panel assembly <NUM>. The liquid panel assembly <NUM> is configured to operate at low pressure. That is, the liquid panel assembly <NUM> provides a low pressure assembly. The liquid that flows through the liquid panel assembly <NUM> has a particular weight and viscosity. For example, a desiccant is a dense fluid. The weight of the liquid creates fluid pressure. As the liquid flows from the top of the liquid panel assembly <NUM> to the bottom, the pressure from the weight of the liquid builds. As the liquid moves through the liquid panel assembly <NUM>, the pressure is reduced through friction, for example. For example, the faster the speed of the liquid within a liquid circuit, the greater the friction between the liquid and walls of channels and passages that define the liquid circuit. Therefore, increasing the speed of the liquid, such as through pumping, increases the frictional force. Embodiments of the present disclosure provide a liquid panel assembly that balances the loss of pressure from friction with the pressure of the weight of the liquid.

The friction head loss, hf, of a fluid flowing in a channel of length L is given by the following: <MAT> where C is a coefficient that depends on the duct geometry (and may also be used to represent the friction of porous material in the duct), µ is the molecular viscosity of the fluid, V is the bulk speed of the fluid in the duct, g is the acceleration due to gravity, ρ is the density of the fluid, and Dh is the hydraulic diameter of the duct. The friction head loss may be synonymous with pressure drop ("head" refers to the height of a column of fluid that would produce the pressure, that is, ΔP = -ρghf.

Embodiments of the present disclosure provide a liquid panel assembly in which friction head loss may be the same or approximately the same as a drop in vertical elevation of the fluid as it flows downward in the channels, due to the gain in static pressure, which is given by ΔP = ρgΔz, where Δz is the drop in vertical elevation (in the direction of gravity). Therefore, adding the two pressure changes together gives ΔPnet = ρg(Δz - hf). A closely balanced flow with low pressure would have Δz ≈ hf. Embodiments of the present disclosure provide pressure balancing channels at the ends of the panel that are oriented vertically, therefore, Δz = L. As such, the following may be consulted when selecting the size, shape, orientation, and the like of the fluid circuits: <MAT> However, complete balance as shown in the above equation is not necessarily required. Instead, the gauge pressure may be kept low enough to meet structural limitations of the membrane and support design (keeping membrane strain and stress within acceptable limits).

In an example, the weight of the liquid produces pressure in the vertical inlet and outlet channels <NUM> and <NUM>, respectively. However, it has been found that increasing the number of horizontal fluid passages <NUM> connecting to particular inlet and outlet channels <NUM> and <NUM> increases the rate of fluid flow within the vertical inlet and outlet channels <NUM> and <NUM>, respectively. Fluid velocity is directly proportional to friction. Thus, with increased fluid velocity, friction increases. The friction diminishes the overall pressure of the liquid within the liquid panel assembly <NUM>. Therefore, by increasing the friction of the fluid with the walls of the channels and passages of the liquid panel assembly <NUM>, the pressure is reduced. As an example, it has been found that connecting single vertical inlet and outlet channels <NUM> and <NUM>, respectively, to sets of four or five horizontal fluid passages <NUM> may substantially or completely offset the pressure caused by the weight of a desiccant. Because different liquids have different densities and weights, the liquid panel assembly <NUM> may be configured to account for the differences in densities and weights. For example, the sets of horizontal flow passages <NUM> may be smaller, such as set of <NUM> or <NUM>, for lighter liquids, than for heavier liquids. Therefore, a number of flow passages <NUM> within a set of multiple flow passages <NUM> connected to individual channels <NUM> and <NUM> may be based on and/or determined by a weight of the liquid that is configured to flow through fluid circuits that include the sets of liquid passages and channels <NUM> and <NUM>. In general, embodiments of the present disclosure are configured to offset hydrostatic pressure gain of the liquid with friction pressure loss of the flowing liquid within one or more fluid circuits to minimize or eliminate pressure within a liquid panel assembly.

Additionally, the hydraulic diameters of the inlet and outlet channels <NUM> and <NUM>, as well as the hydraulic diameters of the horizontal fluid passages <NUM>, may be adjusted to balance liquid hydrostatic pressure with friction. For example, the hydraulic diameter of each channel or passage may be directly proportional to the velocity of liquid flowing therethrough. Thus, decreasing the hydraulic diameter of the channel or passage leads to an increased velocity of pumped liquid therethrough. As noted, increasing liquid velocity increases friction, which reduces the net pressure. Therefore, the hydraulic diameter of the channels <NUM> and <NUM> may be based on and/or determined, in part, by a weight of the liquid that is configured to flow through fluid circuits that include the channels <NUM> and <NUM>. In addition to the number of horizontal flow passages <NUM> in a set that connect to individual vertical inlet and outlet channels <NUM> and <NUM>, respectively, the hydraulic diameter of the channels <NUM> and <NUM>, as well as the flow passages <NUM> may be sized and shaped to generate a desired friction with respect to a particular liquid.

Thus, the liquid panel assembly <NUM> includes liquid circuits that are configured to balance the force of liquid hydrostatic pressure and friction by adjusting the number of horizontal flow passages <NUM> that connect to the vertical inlet and outlet channels <NUM> and <NUM>, respectively, and/or the hydraulic diameter of the channels and/or passages, in order to reduce the net pressure within the liquid panel assembly <NUM>.

The hydraulic diameters of the horizontal fluid passages <NUM> may be relatively wide compared to the vertical inlet and outlet channels <NUM> and <NUM>, respectively. As such, the friction in relation to the liquid in the horizontal fluid passages <NUM> may be relatively small compared to the vertical inlet and outlet channels <NUM> and <NUM>, respectively. The pressure drop in the horizontal fluid passages <NUM> may be relatively small. Because less friction in the horizontal flow passages <NUM> may be desired, the hydraulic diameters of the flow passages <NUM> may be wider than the hydraulic diameters of the vertical inlet and outlet channels <NUM> and <NUM>, respectively. Therefore, the balancing of liquid hydrostatic pressure and friction may be achieved through the velocity of liquid through the vertical inlet and/or outlet channels <NUM> and <NUM>, respectively, which may be controlled through the number of horizontal flow passages <NUM> connecting to each channel <NUM> and <NUM>, and/or the hydraulic diameters of the channels <NUM> and <NUM>.

Referring to <FIG>, <FIG>, and <FIG>, the lengths of the horizontal flow passages <NUM> may be substantially longer than half the length L of the support frame <NUM>. Indeed, the lengths of the horizontal flow passages may be almost as long as the length L of the support frame <NUM>. For example, the horizontal flow passages <NUM> may be the length of the support frame <NUM> minus the horizontal area occupied by the inlet and outlet channels <NUM> and <NUM>, respectively. Accordingly, each fluid circuit may have a substantial length along a horizontal orientation. The linear, horizontal distances of the horizontal flow passages <NUM> increase the efficiency of energy exchange between the liquid flowing therethrough, and the airflow on either side of the membranes of the solution panel assemblies <NUM>. As shown in <FIG>, the horizontal flow passages <NUM> increase the flow of liquid in the horizontal direction so that the direction of liquid flow DL is counter to the direction of airflow DA. It has been found that increasing the distance of counterflow between the liquid in the fluid circuits and the airflow increases the efficiency of energy exchange therebetween. A counterflow arrangement of the air and liquid streams provides an efficient and highly effective energy exchanger. The horizontal flow passages <NUM> maximize the counterflow area, and allow the liquid to distribute evenly. As noted above, however, the flow passages <NUM> may be alternatively be configured to provide crossflow, parallel-aligned flow, or other such flow.

<FIG> illustrates a chart of fluid pressure levels within a liquid panel assembly <NUM>, according to an embodiment. As shown in <FIG>, the pressure level of liquid through an inlet length Li (over the length of the vertical inlet channel <NUM>) increases until the liquid passes into the horizontal flow passage <NUM>, through which the pressure level Lc remains constant. The pressure of the liquid in the vertical outlet channel <NUM> increases. However, as shown in <FIG>, the friction of the liquid with respect to the liquid panel assembly <NUM> offsets the pressure levels of the liquid. As such, the pressure force <NUM> of the liquid is offset by the frictional force <NUM>, thereby yielding a neutral pressure <NUM> within the liquid panel assembly <NUM>. The vertical inlet and outlet channels <NUM> and <NUM>, respectively, may be considered friction control members that are used to balance the pressure within the liquid panel assembly <NUM>.

<FIG> illustrates a front view of a support frame <NUM> of a liquid panel assembly <NUM>, according to an embodiment. The support frame <NUM> may include end sections <NUM> and <NUM> and an intermediate body <NUM>. The end section <NUM> may provide vertical inlet channels <NUM>, while the end section <NUM> may provide vertical outlet channels <NUM>, or vice versa. The intermediate body <NUM> may provide horizontal flow passages <NUM>. The intermediate body <NUM> includes flow passage sets <NUM>-<NUM> that are staggered and/or offset with one another with respect to a vertical axis <NUM> of the intermediate body <NUM>. Each of the end sections <NUM> and <NUM>, as well as the intermediate body <NUM> may be formed from extruded parts and assembled together, such as through fasteners, bonding, and the like. The end sections <NUM>, <NUM>, and the intermediate body <NUM> may be formed by extruding a flat sheet of plastic or metal, and then embossing the channel shapes using grooved rollers, for example.

Alternatively, any of the liquid panel assemblies described above may be formed through injection molding either as separate sub-parts that are later bonded together, or as a single, unitary piece. Injection molding the liquid panel assembly as a single piece, for example, eliminates the potential for joint failure or leakage at bonded seams.

<FIG> illustrates an isometric top view of liquid inlet channels <NUM> formed in a support frame <NUM>, according to an embodiment. As shown, the inlet channels <NUM> may be grooves formed between ridges <NUM> in the support frame <NUM>. The liquid outlet channels may be formed in a similar manner.

<FIG> illustrates an isometric top view of liquid inlet channels <NUM> formed in a support frame <NUM>, according to an embodiment. In this embodiment, the inlet channels <NUM> may be cut completely through the support frame <NUM>, thereby forming a planar channel through the support frame <NUM>. The liquid outlet channels may be formed in a similar manner.

Referring to <FIG>, as explained above, the inlet channels and the outlet channels of the support frame may be vertical and linear, while the flow passages may be horizontal and linear. It has been found that the linear vertical and horizontal configuration of each liquid circuit provides for efficient pressure balancing within the solution panel assemblies. However, the liquid circuits may be various other shapes and sizes. As discussed above, a liquid circuit may include a vertical inlet channel, one or a set of horizontal flow passages, and a vertical outlet channel.

<FIG> illustrates a simplified view of a liquid circuit <NUM>, according to an embodiment. The liquid circuit <NUM> includes a vertical inlet channel <NUM> connected to a vertical outlet channel <NUM> through a flow passage <NUM>. The flow passage <NUM> may include a first horizontal portion <NUM> connected to a second horizontal portion <NUM> through a vertical drop <NUM>. The vertical drop <NUM> may be configured to balance liquid hydrostatic pressure, similar to the vertical inlet and outlet channels, as explained above.

<FIG> illustrates a simplified view of a liquid circuit <NUM>, according to an embodiment. The liquid circuit <NUM> includes a vertical inlet channel <NUM> connected to a vertical outlet channel <NUM> through a flow passage <NUM>. The flow passage <NUM> may include a first horizontal portion <NUM> connected to a second horizontal portion <NUM> through a vertical drop <NUM>. The liquid flow passage <NUM> may also include a third horizontal portion <NUM> connected to the second horizontal portion <NUM> through a vertical drop <NUM>. The vertical drops <NUM> and <NUM> may be configured to balance liquid hydrostatic pressure, similar to the vertical inlet and outlet channels, as explained above. The flow passage <NUM> may include more vertical drops than those shown.

<FIG> illustrates a simplified view of a liquid circuit <NUM>, according to an embodiment. In this embodiment, a vertical inlet channel <NUM> is connected to a vertical outlet channel <NUM> through a flow passage <NUM>, which may be non-linear. When non-linear, the flow passage <NUM> may include offsetting portions such that a trough <NUM> is offset by a peak <NUM>. That is, the depth of the trough <NUM> may be the same absolute distance as the height of the peak <NUM>.

Referring to <FIG>, for example, the liquid circuits may or may not include horizontal passages. For example, the liquid circuits may include vertical flow channels connected to one another through various passages. Pressure balancing may occur directly in the vertical flow channels. Additionally, the liquid circuits may be angled with respect to horizontal and vertical orientations.

<FIG> illustrates an isometric view of horizontal liquid panel assemblies connected to combined inlet channels and combined outlet channels <NUM> according to an embodiment of the present disclosure. One or more panel assemblies <NUM> may be stacked horizontally to form a panel stack <NUM>. The panel assemblies <NUM> may be separated by membrane support assemblies, such as described with respect to <FIG>. The panel assemblies <NUM> may be fluidly connected proximate the left corner <NUM> to an inlet channel <NUM>. The inlet channel <NUM> may be fluidly connected to an inlet header <NUM>. The panel assemblies are fluidly connected proximate the right corner <NUM> to an outlet channel <NUM>. The outlet channel <NUM> is fluidly connected to an outlet header <NUM>. Liquid, such as a desiccant, flows from the inlet header <NUM> into the inlet channel <NUM> and into the panel assembly <NUM> at the corner <NUM>. The liquid passes through the panel assembly <NUM> by traveling along a liquid path, such as described with respect to <FIG>. The liquid exits the panel assembly <NUM> at the corner <NUM> and flows into the outlet channel <NUM> and into the outlet header <NUM>. The inlet channel <NUM> may provide a pressure balancing function for low pressure supply to every panel assembly <NUM> in the panel stack <NUM>. The outlet channel <NUM> may provide a pressure balancing effect for low back pressure to every panel assembly <NUM> in the panel stack <NUM>.

<FIG> illustrates an isometric view of horizontal liquid panel assemblies connected to individual inlet channels and individual outlet channels <NUM> according to an embodiment of the present disclosure. One or more panel assemblies <NUM> may be stacked horizontally to form a panel stack <NUM>. The panel assemblies <NUM> may be separated by membrane support assemblies, such as described with respect to <FIG>. The panel assemblies <NUM> may be fluidly connected proximate the right corner <NUM> to an inlet channel <NUM>. The inlet channel <NUM> may be fluidly connected to an inlet header <NUM>. The panel assemblies may be fluidly connected proximate the left corner <NUM> to an outlet channel <NUM>. The outlet channel <NUM> may be fluidly connected to an outlet header <NUM>. Liquid, such as a desiccant, flows flow from the inlet header <NUM> into the inlet channel <NUM> and into the panel assembly <NUM> at the corner <NUM>. The liquid passes through the panel assembly <NUM> by traveling along a liquid path, such as described with respect to <FIG>. The liquid exits the panel assembly <NUM> at the corner <NUM> and flows into the outlet channel <NUM> and into the outlet header <NUM>. The inlet channel <NUM> may provide a pressure balancing function for low pressure supply to every panel assembly <NUM> in the panel stack <NUM>. The outlet channel <NUM> may provide a pressure balancing effect for low back pressure to every panel assembly <NUM> in the panel stack <NUM>.

<FIG> illustrates an isometric view of stacked horizontal liquid panel assemblies connected to inlet headers <NUM> according to an embodiment of the present disclosure. One or more panel assemblies <NUM> may be stacked horizontally to form a panel stack <NUM>. One or more panel stacks <NUM> may be stacked to form a stack of panel stacks <NUM>. The panel assemblies <NUM> may be separated by membrane support assemblies, such as described with respect to <FIG>. All panel assemblies <NUM> in one panel stack <NUM> may be fluidly connected proximate the right corner <NUM> to one inlet header <NUM>. The inlet header <NUM> may be fluidly connected to an inlet channel <NUM>. The panel assemblies may be fluidly connected proximate the left corner <NUM> to an outlet header <NUM>. The outlet header <NUM> may be fluidly connected to an outlet channel <NUM>. Liquid, such as a desiccant, flows to flow along a fluid path <NUM> from the inlet channel <NUM> into the inlet header <NUM> and into each panel assembly <NUM> in the panel stack <NUM> at the corner <NUM>. The liquid passes through the panel assemblies <NUM> by traveling along a liquid path, such as described with respect to <FIG>. The liquid exits the panel assemblies <NUM> at the corner <NUM> and flows into the outlet header <NUM> and into the outlet channel <NUM>. The inlet channel <NUM> may provide a pressure balancing function for low pressure supply to every panel stack <NUM> in the stack of panel stacks <NUM>. The outlet channel <NUM> may provide a pressure balancing effect for low back pressure to every panel stack <NUM> in the stack of panel stacks <NUM>.

<FIG> illustrates an isometric view of stacked horizontal liquid panel assemblies with external pressure balancing <NUM> according to an embodiment of the present disclosure. One or more panel assemblies <NUM> may be stacked horizontally to form a panel stack <NUM>. One or more panel stacks <NUM> may be stacked to form a stack of panel stacks <NUM>. The panel assemblies <NUM> may be separated by membrane support assemblies such as described with respect to <FIG>. All panel assemblies <NUM> in one panel stack <NUM> may be fluidly connected proximate the right corner <NUM> to one inlet header <NUM>. The inlet header <NUM> may be fluidly connected to a pressure control device such as an inline regulating valve, a pressure regulating pump or other such device capable of supplying fluid to all inlet headers at the same pressure. The panel assemblies may be fluidly connected proximate the left corner <NUM> to an outlet header <NUM>. The outlet header <NUM> may be fluidly connected to a pressure control device such as an inline regulating valve, a pressure regulating pump or other such device capable of retrieving fluid from all outlet headers at the same pressure. Fluid, such as a desiccant, flows along a fluid path <NUM> from the pressure control device into the inlet header <NUM> and into each panel assembly <NUM> in the panel stack <NUM> at the corner <NUM>. The liquid passes through the panel assemblies <NUM> by traveling along a liquid path, such as described with respect to <FIG>. The liquid exits the panel assemblies <NUM> at the corner <NUM> and flows into the outlet header <NUM> and into the pressure control device. The inlet pressure control device may provide low pressure supply to every panel stack <NUM> in the stack of panel stacks <NUM>. The outlet pressure control device may provide low back pressure to every panel stack <NUM> in the stack of panel stacks <NUM>.

Embodiments of the present disclosure may be used with various types of energy exchangers, such as liquid-to-air or liquid-to-liquid membrane energy exchangers.

Embodiments of the present disclosure provide liquid panel assemblies that are configured to balance internal liquid hydrostatic pressure and frictional forces. As such, the total pressure within the liquid panel assemblies may be reduced, negated or otherwise neutralized. Thus, membrane bulge is substantially reduced or eliminated, which reduces the potential for leaks and membrane creep.

Embodiments of the present disclosure provide a liquid panel assembly divided into a plurality of separate liquid circuits, each of equal length and friction, so that liquid divides itself evenly among the liquid circuits and the flow through the liquid circuits is uniform. The fluid circuits promote uniform flow distribution across the liquid panel assembly, thereby providing efficient operation and performance.

Embodiments of the present disclosure provide a liquid panel assembly that creates pathways for controlled, uniform, flow distribution (such as counterflow distribution) of liquid, such as desiccant, over an internal membrane area. Further, the liquid panel assembly provides low operating pressure by offsetting the static pressure gain and friction pressure loss as the liquid moves through the liquid circuits. The vertical flow of liquid may be confined to small high speed channels, thereby reducing or eliminating the potential for buoyancy-driven mal-distribution of liquid. The flow passages may be open (no filler wick or mesh), thereby allowing for good contact of the liquid and membrane, and low friction loss.

Embodiments of the present disclosure are not restricted to energy exchangers. Instead, embodiments of the present disclosure may be used with respect to any liquid panel frame that exchanges heat and/or mass through a membrane, and where liquid pressure and flow distribution are controlled. For example, the liquid panel assemblies described above may be used with desalination systems, water purification systems, evaporative cooling systems, systems configured to transfer heat/mass between a liquid and a gas through a membrane, systems configured to transfer heat/mass between two liquid streams through a membrane, and the like.

Embodiments of the present invention may further comprise features as defined by the following statements.

A liquid panel assembly comprising a support frame having one or more fluid circuits, wherein each of the one or more fluid circuits comprises an inlet channel connected to an outlet channel through one or more flow passages.

The liquid panel assembly further comprising at least one membrane secured to the support frame, wherein a liquid is configured to flow through the one or more fluid circuits and contact interior surfaces of the at least one membrane, and wherein the one or more fluid circuits are configured to at least partially offset hydrostatic pressure gain with friction pressure loss of the liquid that flows within the one or more fluid circuits to reduce pressure within the liquid panel assembly.

The one or more flow passages may comprise one or more counterflow passages. The shape, porosity, or hydraulic diameter of one or both of the inlet and outlet channels may be determined by a weight, viscosity, or flow speed of the liquid that is configured to flow through the one or more fluid circuits. The inlet channel may be disposed at an upper corner of the support frame, and the outlet channel is disposed at a lower corner of the support frame. The upper corner may be diagonally located from the lower corner. The inlet and outlet channels may be vertical and the one or more flow passages may be horizontal. A horizontal length of the one or more flow passages may exceed half a total horizontal length of the support frame. The one or more flow passages may comprise a set of a plurality of flow passages connected to the inlet channel and the outlet channel. A number of flow passages within the set of a plurality of flow passages may be determined by a weight of the liquid that is configured to flow through the one or more fluid circuits.

The one or more fluid circuits may comprise a plurality of fluid circuits. The lengths of each of the one or more fluid circuits may be equal. The plurality of fluid circuits may comprise a first set of a plurality of flow passages connected to a first inlet channel and a first outlet channel. The plurality of fluid circuits may further comprise a second set of a plurality of flow passages connected to a second inlet channel and a second outlet channel. The first set of a plurality of flow passages may be staggered with respect to the second set of a plurality of flow passages. The support frame and the at least one membrane may be configured to be vertically oriented within an energy exchange cavity of an energy exchanger.

The liquid panel assembly may further comprise inlet and outlet members connected to the at least one fluid circuit. The inlet and outlet members may comprise a liquid delivery channel and a liquid passage channel, respectively. The inlet member may be configured to modularly engage another inlet member and the outlet member may be configured to modularly engage another outlet member. At least a portion of the at least one membrane may sealingly engage the inlet and outlet members.

Each of the inlet and outlet channels may provide a flow alignment vane configured to direct the liquid to flow along a particular path, wherein the inlet and outlet channels are configured to provide support to the at least one membrane, and wherein the inlet and outlet channels are configured to provide a sealing surface for at least a portion of the at least one membrane. The inlet and outlet channels may be configured to maximize a length of the one or more flow passages. The at least one membrane may be continuously bonded around a perimeter of the support frame. The one or more fluid circuits may be configured to provide a uniform liquid flow distribution across the liquid panel assembly. The one or more fluid circuits may be configured to substantially offset the hydrostatic pressure gain with the friction pressure loss of the liquid that flow within the one or more fluid circuits to reduce pressure within the liquid panel assembly.

An energy exchange system comprising a plurality of air channels configured to allow air to pass therethrough; a plurality of liquid panel assemblies alternately spaced with the plurality of air channels. Each of the plurality of liquid panel assemblies comprising: a support frame having one or more fluid circuits, wherein each of the one or more fluid circuits comprises an inlet channel connected to an outlet channel through one or more flow passages; and at least one membrane secured to the support frame, wherein a liquid is configured to flow through the one or more fluid circuits and contact interior surfaces of the at least one membrane, and wherein the one or more fluid circuits are configured to at least partially offset hydrostatic pressure gain with friction pressure loss of the liquid that flows within the one or more fluid circuits to reduce pressure within the liquid panel assembly.

The one or more flow passages may comprise one or more counterflow passages. The energy exchange system may further comprise a plurality of membrane support assemblies disposed within the plurality of air channels. The shape, porosity, or hydraulic diameter of one or both of the inlet and outlet channels may be determined by a weight, viscosity, or flow speed of the liquid that is configured to flow through the one or more fluid circuits. The inlet channel may be disposed at an upper corner of the support frame, and the outlet channel may be disposed at a lower corner of the support frame. The upper corner may be diagonally located from the lower corner. The inlet and outlet channels may be vertical and the one or more flow passages may be horizontal. A horizontal length of the one or more flow passages may exceed a total horizontal length of the support frame. The one or more flow passages may comprise a set of a plurality of flow passages connected to the inlet channel and the outlet channel. A number of flow passages within the set of a plurality of flow passages may be determined by a weight and/or viscosity of the liquid that is configured to flow through the one or more fluid circuits.

The one or more fluid circuits may comprise a plurality of fluid circuits. The lengths of each of the one or more fluid circuits may be equal. The plurality of fluid circuits may comprise a first set of a plurality of flow passages connected to a first inlet channel and a first outlet channel. The plurality of fluid circuits may further comprise a second set of a plurality of flow passages connected to a second inlet channel and a second outlet channel. The first set of a plurality of flow passages may be staggered with respect to the second set of a plurality of flow passages. The support frame and the at least one membrane may be configured to be vertically oriented within an energy exchange cavity of the energy exchanger.

The energy exchange system may further comprise inlet and outlet members connected to the at least one fluid circuit. The inlet and outlet members may comprise a liquid delivery channel and a liquid passage channel, respectively. The inlet member may be configured to modularly engage another inlet member, and the outlet member may be configured to modularly engage another outlet member. Air within the plurality of air channels may be configured to counterflow with respect to the liquid within the one or more flow passages. At least a portion of the at least one membrane may sealingly engage the inlet and outlet members. Each of the inlet and outlet channels may provide a flow alignment vane configured to direct the liquid to flow along a particular path, wherein the inlet and outlet channels are configured to provide support to the at least one membrane, and wherein the inlet and outlet channels are configured to provide a sealing surface for at least a portion of the at least one membrane. The inlet and outlet channels may be configured to maximize a length of the one or more flow passages. The at least one membrane may be continuously bonded around a perimeter of the support frame. The one or more fluid circuits may be configured to substantially offset the hydrostatic pressure gain with the friction pressure loss of the liquid that flows within the one or more fluid circuits to reduce pressure within the liquid panel assembly.

While various spatial and directional terms, such as top, bottom, lower, mid, lateral, horizontal, vertical, front and the like may be used to describe embodiments of the present disclosure, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like.

It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the various embodiments of the disclosure without departing from their scope. While the dimensions and types of materials described herein are intended to define the parameters of the various embodiments of the disclosure, the embodiments are by no means limiting and are exemplary embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the various embodiments of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein. " Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

Claim 1:
A liquid panel assembly (<NUM>) for a liquid-to-air membrane energy exchanger (<NUM>, <NUM>, <NUM>), the liquid panel assembly (<NUM>) comprising:
a support frame (<NUM>); and
first and second semi-permeable membranes (<NUM>, <NUM>) secured to first and second sides of the support frame (<NUM>),
characterised in that the support frame has a plurality of liquid circuits (<NUM>) through which a liquid is configured to flow, each of the liquid circuits (<NUM>) comprising an inlet channel (<NUM>) connected to an outlet channel (<NUM>) through a plurality of flow passages (<NUM>).