Three-way heat exchanger and method of operating three-way heat exchanger

Abstract

The disclosure relates to a three-way heat exchanger and a method of operating a three-way heat exchanger. The heat exchanger includes a panel assembly arranged with an airflow gap defined between adjacent plate assemblies to allow air to flow in an airflow direction. Each panel assembly includes a frame having two header sections and an intermediate section, a membrane positioned on the frame, and two airflow restrictor members positioned at each header section of the frame. For each header section, a first airflow restrictor member is located on a first face of the frame and a second airflow restrictor member is located on a second face of the frame. For each pair of adjacent panel assemblies, the intermediate sections are spaced apart to define an airflow gap, and the first airflow restrictor member of the first panel assembly engages the second airflow restrictor member of the second panel assembly to form two airflow restrictors at opposite ends of the airflow gap with respect to a direction different from the airflow direction.

Description

Technical Field

[0001] This field generally relates to heating, ventilation, and air conditioning (HVAC) systems, and more particularly to HVAC systems and methods including a three-way heat exchange module for transferring heat between a heat transfer fluid, a liquid desiccant, and air. Background Art

[0002] Heating, ventilation, and air conditioning (HVAC) systems are known for their ability to handle heating, cooling, and moisture removal of outside air circulated through an indoor space. The vapor compression cycle is widely used in HVAC systems to condition the temperature and humidity of outside air. Typically, outside air is cooled below its dew point temperature to allow moisture in the air to condense on the evaporator coil, thereby dehumidifying the air. Since this process typically results in the dehumidified air being at an uncomfortably low temperature, the air is reheated to a more comfortable temperature for the user. The process of over-cooling and reheating the air can be very energy-consuming and expensive.

[0003] In some applications, an HVAC system includes a vapor compression system used in combination with a liquid desiccant dehumidification system to remove moisture from outside air without cooling the outside air below its dew point temperature. For example, an HVAC system can include a refrigerant subsystem operating under a vapor compression cycle and an air handling subsystem that uses a heat transfer fluid and a liquid desiccant to simultaneously absorb heat (sensible cooling) and moisture (latent cooling) from warm outside air to produce cooled and dehumidified indoor air. The air handling subsystem can include a three-way heat transfer device that facilitates sensible cooling and latent cooling of warm outdoor air using the heat transfer fluid and the liquid desiccant.

[0004] In the operation of a three-way heat exchanger, the liquid desiccant and the heat transfer fluid are directed through the heat exchanger, and heat is transferred between the liquid desiccant and the heat transfer fluid. An outside air stream is directed through the heat exchanger, and the heat transfer fluid absorbs heat from the air stream while the liquid desiccant absorbs moisture from the air stream. The liquid desiccant can be circulated between the three-way heat exchanger and a regeneration system, where the diluted liquid desiccant discharges the absorbed moisture into a sacrificial fluid. The refrigerant subsystem engages with the air handling subsystem, whereby the refrigerant absorbs heat from the heat transfer fluid in the three-way heat exchanger during the evaporation stage of the vapor compression cycle. The refrigerant is then directed to a condensation stage, in which the refrigerant discharges the absorbed heat into another fluid. The liquid desiccant treated by the regeneration system and the heat transfer fluid treated by the refrigerant subsystem are then directed back to the three-way heat exchanger to again provide sensible cooling and latent cooling of the outside air.

[0005] A three-way heat exchanger may include a panel that guides a heat transfer fluid and a liquid desiccant through the three-way heat exchanger for absorbing heat and moisture from an air stream flowing between the panels. The heat transfer fluid and the liquid desiccant may flow through the panel and be distributed over respective flow channels in each panel. There is a continuing need to improve the design and / or manufacturability of the panel to facilitate cost reduction and / or optimize the operation and efficiency of the heat exchanger.

[0006] This Background of the Invention section is intended to introduce to the reader various aspects of the art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful to provide the reader with background information to facilitate a better understanding of various aspects of the present disclosure. These statements are to be read from this perspective and are not to be taken as an admission of prior art. Summary of the Invention

[0007] One aspect is a three-way heat exchanger operable to transfer heat between a heat transfer fluid, a liquid desiccant, and air. The three-way heat exchanger includes an air flow inlet, an air flow outlet, and a panel assembly arranged to have an air flow gap defined between adjacent panel assemblies to allow air to flow between the air flow inlet and the air flow outlet in the air flow direction. Each panel assembly includes: a frame that includes two header sections and an intermediate section extending between the header sections, the intermediate section defining a heat transfer fluid channel; a membrane positioned on the frame and defining a desiccant channel; and two air flow restrictor members positioned at each header section of the frame. For each header section, a first air flow restrictor member is located on a first face of the frame, and a second air flow restrictor member is located on a second face of the frame. For each pair of adjacent panel assemblies, the intermediate sections of the adjacent panel assemblies are spaced apart to define the air flow gap, and the first air flow restrictor member of the first panel assembly engages the second air flow restrictor member of the second panel assembly to form two air flow restrictors in the air flow gap. The air flow restrictors are located at opposite ends of the air flow gap in a direction different from the air flow direction.

[0008] On the other hand, there is a three-way heat exchanger for transferring heat between a heat transfer fluid, a liquid desiccant, and air. The three-way heat exchanger defines lateral, longitudinal, and vertical directions that are perpendicular to each other. The three-way heat exchanger includes an air flow inlet, an air flow outlet, and a panel assembly. The panel assembly is arranged in the lateral direction and has an air flow gap defined between adjacent panel assemblies to allow air to flow in the longitudinal direction between the air flow inlet and the air flow outlet. Each panel assembly includes a frame defining a heat transfer fluid channel and a membrane positioned on the frame and defining a desiccant channel. The three-way heat exchanger further includes two air flow limiters located in each air flow gap between each pair of adjacent panel assemblies. Each air flow limiter defines a tortuous path for air to flow in the vertical direction. For each pair of adjacent panel assemblies, one of the air flow limiters is vertically positioned above the heat transfer fluid channel and the desiccant channel, and the other air flow limiter is vertically positioned below the heat transfer fluid channel and the desiccant channel.

[0009] On the other hand, there is a method of operating a three-way heat exchanger. The method includes: guiding a heat transfer fluid through the panel assembly of the three-way heat exchanger, where each panel assembly includes a frame defining a heat transfer fluid channel through which the heat transfer fluid is guided; guiding a liquid desiccant through the desiccant channel of the panel assembly, the desiccant channel being defined between the frame of the panel assembly and a membrane attached to the frame; guiding air through the three-way heat exchanger in the air flow direction, where the air flows through the air flow gap defined between adjacent panel assemblies; and using air flow limiters positioned in the air flow gap to restrict the flow of air guided through the three-way heat exchanger in a direction different from the air flow direction.

[0010] There are various improvements to the features pointed out in the above aspects. Other features can also be incorporated into the above aspects. These improvements and additional features can exist alone or in any combination. For example, each of the features discussed below with respect to any of the illustrated embodiments can be incorporated into any of the above aspects alone or in any combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic flow chart of a heating, ventilation, and air conditioning (HVAC) system.

[0012] Figure 2 is included in Figure 1 the front perspective view of the three-way heat exchanger in the HVAC system of

[0013] Figure 3 is the front perspective view of the three-way heat exchanger, where various components are omitted to show the internal components.

[0014] Figure 4 It is a rear perspective view of a three-way heat exchanger.

[0015] Figure 5 It is a rear perspective view of a three-way heat exchanger, where various components are omitted similar to Figure 3 .

[0016] Figure 6 It is a left front view of a three-way heat exchanger, where various components are omitted similar to Figure 3 and Figure 5 .

[0017] Figure 7 It is a right front view of an exemplary panel assembly included in the three-way heat exchanger in Figures 2 to 6 .

[0018] Figure 8 It is Figure 7 an exploded view of the panel assembly.

[0019] Figure 9 It is a schematic cross-section of the panel assembly taken along the section line 9-9 in Figure 7 .

[0020] Figures 10A to 10D They are enlarged views of sections A, B, C, and D shown in Figure 8 respectively.

[0021] Figure 11 It is a schematic diagram showing the flow of liquid desiccant and heat transfer fluid through the three-way heat exchanger in Figures 2 to 6 .

[0022] Figure 12 It is Figure 7 a separate right front view of the frame of the panel assembly.

[0023] Figure 12A and Figure 12B They are enlarged views of regions 12A and 12B in Figure 12 respectively.

[0024] Figure 13 It is a separate left front view of the frame.

[0025] Figure 13A and Figure 13B They are enlarged views of regions 13A and 13B in Figure 13 respectively.

[0026] Figure 14 It is a separate front view of the frame.

[0027] Figure 15 It is a front view of three adjacent frames positioned for assembly in the heat exchanger.

[0028] Figure 16 is Figure 15 a cross-section of the area indicated by the box labeled 16 in

[0029] Figure 17 is Figure 15 a cross-section of the area indicated by the box labeled 17 in

[0030] Figure 18 is Figure 16 another view of the cross-section that shows a frame being detached from an adjacent frame.

[0031] Figure 19 is an example method of operating a three-way heat exchanger.

[0032] Throughout the figures, corresponding reference numerals indicate corresponding parts. DETAILED DESCRIPTION

[0033] Figure 1 is a schematic diagram of a heating, ventilation, and air conditioning (HVAC) system 100. The HVAC system 100 includes subsystems 102 to 106 and a liquid desiccant loop 108 that facilitate the heating, cooling, and moisture removal capabilities of the system 100. The subsystems of the HVAC system 100 include a refrigerant subsystem 102, a conditioner subsystem 104, and a regenerator subsystem 106. The conditioner subsystem 104 and the regenerator subsystem 106 can be used to process a first inlet air stream 110 and a second inlet air stream 114, respectively, and can be referred to herein as air handling subsystems 104 and 106. The HVAC system 100 can include additional components or other components in addition to those shown and described with reference to Figure 1 those shown and described.

[0034] In an example operating mode of the HVAC system 100, the conditioner subsystem 104 removes heat from the first inlet air stream 110 and directs the conditioned outlet air stream 112 to a conditioned space (not shown), such as the interior of a building structure or a vehicle. The conditioned outlet air stream 112 leaving the conditioner subsystem 104 can have a lower temperature than the first inlet air stream 110. The heat removed from the first inlet air stream 110 is transferred from the conditioner subsystem 104 to the refrigerant subsystem 102 and ultimately to the regenerator subsystem 106. The regenerator subsystem 106 transfers heat into the second inlet air stream 114 and directs the heated outlet air stream 116 to the atmosphere.

[0035] The refrigerant subsystem 102 includes an evaporator 118, a condenser 120, a compressor 122, and an expansion valve 124. The compressor 122 can be any suitable compressor, including but not limited to a scroll compressor, a reciprocating compressor, a rotary compressor, a screw compressor, and a centrifugal compressor. The expansion valve 124 can be any suitable expansion valve, such as a thermal expansion valve. The expansion valve 124 can alternatively be any suitable expansion device, such as an orifice or a capillary tube, for example. The refrigerant subsystem 102 also includes a refrigerant loop 126 that circulates a working fluid, such as refrigerant, between the evaporator 118, the compressor 122, the condenser 120, and the expansion valve 124. The refrigerant subsystem 102 can include additional or other components in addition to those shown and described with reference to Figure 1 the components shown and described.

[0036] In an example operation of the refrigerant subsystem 102, the refrigerant in the loop 126 is directed as a low-pressure gaseous refrigerant 128 toward the compressor 122. The compressor 122 compresses the gaseous refrigerant 128, which increases the temperature and pressure of the refrigerant. The pressurized high-temperature gaseous refrigerant 130 leaves the compressor 122 and is directed toward the condenser 120, where the high-pressure gaseous refrigerant 130 is condensed into a high-pressure liquid refrigerant 132. The liquid refrigerant 132 leaving the condenser 120 is directed toward the expansion valve 124, which reduces the pressure of the liquid. The reduced-pressure fluid refrigerant 134, which can be a gas or a mixture of gas and liquid after passing through the expansion valve 124, is then directed toward the evaporator 118. The fluid refrigerant 134 evaporates into a gas in the evaporator 118 and thus leaves the evaporator as a low-pressure gaseous refrigerant 128. The gaseous refrigerant 128 is then directed back to the compressor 122, where the gaseous refrigerant 128 is compressed again and the process repeats. The circulation of the refrigerant in the loop 126 can be driven by the compressor 122, and more specifically, by the pressure difference that exists between the pressurized high-temperature gaseous refrigerant 130 leaving the compressor 122 and the low-pressure gaseous refrigerant 128 entering the compressor 122. As Figure 1 shown, the direction of flow of the refrigerant through the loop 126 can be reversed to switch the heat transfer functions of the evaporator 118 and the condenser 120 and enable the HVAC system 100 to operate in various operating modes.

[0037] The regulator subsystem 104 includes a first three-way heat exchanger 136 and a regulator heat transfer fluid loop 138 that circulates a regulator heat transfer fluid (e.g., water, an ethylene glycol-based fluid, or any combination of water and an ethylene glycol-based fluid) to and from the first three-way heat exchanger 136. The regulator subsystem 104 is engaged with the refrigerant subsystem 102 via the evaporator 118. In particular, the evaporator 118 is included in the refrigerant loop 126 and the regulator heat transfer loop 138 and facilitates the transfer of heat from the regulator heat transfer fluid in loop 138 to the fluid refrigerant 134 in the refrigerant loop 126. The regulator subsystem 104 may include additional or other components in addition to those shown and described with reference to Figure 1 the components shown and described. For example, the regulator subsystem 104 may include one or more pumps (not shown) that are configured to circulate the regulator heat transfer fluid in loop 138 between the first three-way heat exchanger 136 and the evaporator 118. Suitable pumps that may be included in the regulator subsystem 104 include, for example, centrifugal pumps, diaphragm pumps, positive displacement pumps, or any type of pump suitable for transferring liquids. Depending on the operating requirements of the HVAC system 100 and other factors (e.g., the temperature and / or humidity of the first air inlet stream 110), the regulator subsystem 104 may include additional heat transfer devices that transfer heat from the regulator heat transfer fluid to the atmosphere or transfer heat from the atmosphere to the regulator heat transfer fluid.

[0038] In an example operation of the regulator subsystem 104, the regulator heat transfer fluid in loop 138 is directed toward the evaporator 118. The regulator heat transfer fluid is cooled in the evaporator 118 as heat is transferred from the regulator heat transfer fluid to the fluid refrigerant 134 in loop 126 to produce a gaseous refrigerant 128. The cooled regulator heat transfer fluid 140 that exits the evaporator 118 is directed toward and enters the first three-way heat exchanger 136. The first inlet air stream 110 is also directed through the first three-way heat exchanger 136. The first three-way heat exchanger 136 transfers heat from the first inlet air stream 110 to the regulator heat transfer fluid 140, thereby heating the regulator heat transfer fluid. The heated regulator heat transfer fluid 142 that exits the first three-way heat exchanger 136 is directed back to the evaporator 118, and the process is repeated.

[0039] The regenerator subsystem 106 includes a second three-way heat exchanger 144 and a regenerator heat transfer fluid loop 146 that circulates a regenerator heat transfer fluid (e.g., water, an ethylene glycol-based fluid, or any combination of water and an ethylene glycol-based fluid) to and from the second three-way heat exchanger 144. The regenerator subsystem 106 is engaged with the refrigerant subsystem 102 via the condenser 120. In particular, the condenser 120 is included in the refrigerant loop 126 and the regenerator heat transfer loop 146 and facilitates the transfer of heat from the pressurized gaseous refrigerant 130 in the refrigerant loop 126 to the regenerator heat transfer fluid. The regenerator subsystem 106 may include additional or other components in addition to those shown and described with reference to Figure 1 the components shown and described. For example, the regenerator subsystem 106 may include one or more pumps (not shown) that circulate the regenerator heat transfer fluid in loop 146 between the three-way heat exchanger 144 and the condenser 120. Suitable pumps that may be included in the regenerator subsystem 106 include, for example, centrifugal pumps, diaphragm pumps, positive displacement pumps, or any type of pump suitable for transferring liquids. Depending on the operating requirements of the HVAC system 100 and other factors (e.g., the temperature and / or humidity of the first air inlet stream 110), the regenerator subsystem 106 may include additional heat transfer devices that transfer heat from the atmosphere to the regenerator heat transfer fluid or from the regenerator heat transfer fluid to the atmosphere.

[0040] In an example operation of the regenerator subsystem 106, the regenerator heat transfer fluid in loop 146 is directed toward the condenser 120. The regenerator heat transfer fluid is heated in the condenser as heat is transferred from the pressurized gaseous refrigerant 130 in loop 126 to the regenerator heat transfer fluid to produce a liquid refrigerant 132. The heated regenerator heat transfer fluid 148 exiting the condenser is directed toward and enters the second three-way heat exchanger 144. The second inlet air stream 114 is also directed through the second three-way heat exchanger 144. The second three-way heat exchanger 144 transfers heat from the regenerator heat transfer fluid to the second inlet air stream 114, thereby cooling the regenerator heat transfer fluid. The heated outlet air stream 116 exiting the second three-way heat exchanger 144 has a higher temperature than the second inlet air stream 114. The cooled regenerator heat transfer fluid 150 exiting the three-way heat exchanger 144 is directed back to the condenser 120, and the process is repeated.

[0041] The HVAC system 100 also includes a liquid desiccant loop 108 that operates in conjunction with subsystems 102 to 106 to condition the first inlet air stream 110 by latent heat cooling and sensible heat cooling. The liquid desiccant loop 108 includes a liquid desiccant that is directed between a first three-way heat exchanger 136 and a second three-way heat exchanger 144. Suitable liquid desiccants that can be used in the liquid desiccant loop 108 include, for example, desiccant salt solutions such as solutions of water and lithium chloride (LiCl), lithium bromide (LiBr), calcium chloride (CaCl2), or any combination thereof, triethylene glycol, sodium hydroxide, sulfuric acid, and so-called ionic liquid desiccants, or organic salts that are liquid at room temperature and have organic cations and organic or inorganic anions.

[0042] The liquid desiccant loop 108 can include one or more pumps (not shown) for directing the liquid desiccant between the first three-way heat exchanger 136 and the second three-way heat exchanger 144. Suitable pumps that can be included in the liquid desiccant loop 108 include, for example, centrifugal pumps, diaphragm pumps, positive displacement pumps, or any type of pump suitable for transferring liquids. The liquid desiccant loop 108 can include one or more pumps for transferring the liquid desiccant from the second heat exchanger 144 towards the first heat exchanger 136, and one or more pumps for transferring the diluted liquid desiccant 154 from the first heat exchanger 136 towards the second heat exchanger 144.

[0043] The concentrated liquid desiccant 152 in the liquid desiccant loop 108 is directed towards the first three-way heat exchanger 136 of the conditioner subsystem 104, where the concentrated liquid desiccant 152 removes moisture from the first inlet air stream 110. The concentrated liquid desiccant 152 cooperates with the cooled conditioner heat transfer fluid 140 in the first three-way heat exchanger 136 to absorb heat and moisture from the first inlet air stream 110. The conditioned outlet air stream 112 leaving the first three-way heat exchanger 136 can have a lower humidity and / or a lower temperature compared to the first inlet air stream 110. The liquid desiccant that has absorbed moisture from the first inlet air stream 110 leaves the first three-way heat exchanger 136 as the diluted liquid desiccant 154.

[0044] The diluted liquid desiccant 154 is directed toward the second three-way heat exchanger 144 of the regenerator subsystem 106, where the diluted liquid desiccant 154 discharges moisture into the second inlet air stream 114. The diluted liquid desiccant 154 cooperates with the heated regenerator heat transfer fluid 148 in the second three-way heat exchanger 144 to discharge heat and moisture into the second inlet air stream 114. Thus, the heated outlet air stream 116 exiting the second three-way heat exchanger 144 has greater humidity and a higher temperature than the second inlet air stream 114. The liquid desiccant that has discharged moisture into the second inlet air stream 114 exits the regenerator subsystem 106 as the concentrated liquid desiccant 152. The concentrated liquid desiccant 152 exiting the second three-way heat exchanger 144 is directed back to the first three-way heat exchanger 136, and the process is repeated.

[0045] The liquid desiccant loop 108 may further include a desiccant-desiccant heat exchanger 156 that is configured to transfer heat from the concentrated liquid desiccant 152 that has exited the second three-way heat exchanger 144 to the diluted liquid desiccant 154 that has exited the first three-way heat exchanger 136. The desiccant-desiccant heat exchanger 156 may facilitate improving the functionality of the liquid desiccant in the three-way heat exchangers 136 and 144. For example, the desiccant-desiccant heat exchanger 156 may reduce the temperature of the concentrated liquid desiccant 152 to provide greater cooling and dehumidification capabilities of the first three-way heat exchanger 136. Additionally and / or alternatively, the desiccant-desiccant heat exchanger 156 may increase the temperature of the diluted liquid desiccant 154 to enable the diluted liquid desiccant 154 to desorb a greater amount of moisture in the second three-way heat exchanger 144. The desiccant-desiccant heat exchanger 156 may be an inline heat exchanger or any suitable heat exchanger that facilitates direct heat transfer between the concentrated liquid desiccant 152 and the diluted liquid desiccant 154. The desiccant-desiccant heat exchanger 156 may alternatively facilitate indirect heat exchange between the concentrated liquid desiccant 152 and the diluted liquid desiccant 154, such as indirect heat exchange via a vapor compression heat pump. In addition to or instead of the heat exchanger 156, auxiliary heating and cooling sources (e.g., heating and cooling fluids such as water) may be utilized to heat the diluted liquid desiccant 154 and cool the concentrated liquid desiccant 152, respectively. The liquid desiccant loop 108 may include additional or other components in addition to those shown and described with reference to Figure 1 those shown and described.

[0046] Thus, in an example operating mode of the HVAC system 100, sensible cooling of the first inlet air stream 110 is facilitated by the first three-way heat exchanger 136 of the conditioner subsystem 104, which transfers heat from the inlet air stream 110 to the conditioner heat transfer fluid. The heat removed from the first inlet air stream 110 is then sequentially transferred among the subsystems 104, 102, and 106 via the evaporator 118 and the condenser 120, and is ultimately discharged into the second inlet air stream 114 via the second three-way heat exchanger 144. The first three-way heat exchanger 136 also facilitates latent cooling of the first inlet air stream 110, and the first three-way heat exchanger 136 removes moisture from the inlet air stream 110 using concentrated liquid desiccant 152. The moisture absorbed by the diluted liquid desiccant 154 is desorbed into the second inlet air stream 114 in the second three-way heat exchanger 144, which regenerates the concentrated liquid desiccant 152, and then the concentrated liquid desiccant 152 is directed back to the first three-way heat exchanger 136.

[0047] The HVAC system 100 can operate in addition to those described above with reference to Figure 1Operate in alternative operating modes other than the described exemplary operating modes. The exemplary operating modes of the HVAC system 100 described above can be considered as the warm weather operating mode of the HVAC system 100, in which the warm and humid air in the first inlet air stream 110 is cooled and dehumidified using the conditioner subsystem 104, and the heat and moisture removed are transferred by the subsystems 102 and 106 and the liquid desiccant loop 108 and discharged into the second inlet air stream 114 to produce a heated and humidified outlet air stream 116 that is directed to the warm and humid environment. In the cold weather operating mode of the HVAC system 100, the operation of the subsystems 102 to 106 and the liquid desiccant loop 108 can be reversed, such that the first three-way heat exchanger 136 heats and humidifies the cold and dry air in the first inlet air stream 110 to produce warm air with a comfortable humidity level in the outlet air stream 112 that is directed to the conditioned space. In the cold weather operating mode, the flow directions of the refrigerant in the loop 126 and the liquid desiccant in the liquid desiccant loop 108 can be reversed, such that the air handling subsystems 104 and 106 switch their respective functions, or the inlet vents and outlet vents for the first inlet air stream 110 and the second inlet air stream 114 can be rearranged and / or reconfigured such that the air flow directions through the first three-way heat exchanger 136 and the second three-way heat exchanger 144 are reversed, where the outlet air stream 112 is directed back to the surrounding environment and the outlet air stream 116 is directed towards the conditioned space. In other operating modes of the HVAC system 100, depending on the operating requirements and the desired set point temperature and humidity levels in the conditioned space, one of the air handling subsystems 104 and 106 can be idle or omitted from the HVAC system 100. For example, depending on the operating mode of the HVAC system 100, the air handling subsystem 106 can be omitted, and the refrigerant subsystem 104 can discharge or absorb heat from the refrigerant-air heat exchanger 120. In the case where the regenerator subsystem 106 is omitted or idle, the liquid desiccant circulating through the first three-way heat exchanger 136 in the liquid desiccant loop 108 can be regenerated or diluted using auxiliary regeneration equipment, dilution tanks, etc., depending on the operating mode of the HVAC system 100.

[0048] Still referring to Figure 1 , the first three-way heat exchanger 136 and the second three-way heat exchanger 144 have substantially the same configuration. In an alternative embodiment, the first three-way heat exchanger 136 and the second three-way heat exchanger 144 can have different configurations. Although the conditioner subsystem 104 and the regenerator subsystem 106 are in Figure 1are shown as including a three-way heat exchanger 136 and 144, respectively, but any suitable number of three-way heat exchangers 136 and 144 may be included in the respective subsystems 104 and 106. The number of three-way heat exchangers 136 included in the conditioner subsystem 104 may be the same as or different from the number of three-way heat exchangers 144 included in the regenerator subsystem 106. In the case where the conditioner subsystem 104 includes a plurality of three-way heat exchangers 136, the heat exchangers 136 may operate in series, in parallel, or in any combination of series and parallel. In the case where the regenerator subsystem 106 includes a plurality of three-way heat exchangers 144, the heat exchangers 144 may operate in series, in parallel, or in any combination of series and parallel.

[0049] Now referring to Figures 2 to 5 , an example three-way heat exchanger 200 for use in the air handling subsystem of the HVAC system 100 in Figure 1 will now be described. The three-way heat exchanger 200 may be implemented as the first three-way heat exchanger 136 in the conditioner subsystem 104 and / or the second three-way heat exchanger 144 in the regenerator subsystem 106. Figure 2 is a front perspective view of the three-way heat exchanger 200. Figure 3 is a front perspective view of the three-way heat exchanger 200, where various components are omitted to show the internal components of the three-way heat exchanger 200. Figure 4 is a rear perspective view of the three-way heat exchanger 200. Figure 5 is a rear perspective view of the three-way heat exchanger 200, where, similar to Figure 3 , various components are omitted.

[0050] The three-way heat exchanger 200 has dimensions along the X-axis, Y-axis, and Z-axis, respectively. The X-axis, Y-axis, and Z-axis are perpendicular to each other. As described herein with respect to the three-way heat exchanger 200 and the components of the heat exchanger 200 during assembly, the dimension along the Z-axis can be referred to as the "height", the dimension along the Y-axis can be referred to as the "length", and the dimension along the X-axis can be referred to as the "width". The three-way heat exchanger 200 defines a lateral direction along the X-axis, a longitudinal direction along the Y-axis, and a vertical direction along the Z-axis. The X-axis can also be referred to as the lateral axis herein, the Y-axis can also be referred to as the longitudinal axis herein, and the Z-axis can also be referred to as the vertical axis herein. The three-way heat exchanger 200 has opposite first lateral sides 202 and second lateral sides 204, first longitudinal sides 206 and second longitudinal sides 208, and first vertical sides 210 and second vertical sides 212, respectively. The first lateral side 202 and the second lateral side 204 are spaced apart in the lateral direction, the first longitudinal side 206 and the second longitudinal side 208 are spaced apart in the longitudinal direction, and the first vertical side 210 and the second vertical side 212 are spaced apart in the vertical direction. The directional terms are only used to describe the spatial relationship of the three-way heat exchanger 200 and the components of the heat exchanger. The examples shown and described are not limited to any particular orientation.

[0051] The three-way heat exchanger 200 includes a set of panel assemblies 214 (also referred to as multi-layer panels) arranged continuously or in series in the lateral direction between the first lateral side 202 and the second lateral side 204. Each panel assembly 214 will be described in more detail below with reference to Figures 7 to 10D Each panel assembly 214 is in the form of a plate structure having internal heat transfer fluid channels through which heat transfer fluid, such as the conditioner heat transfer fluid in loop 138 or the regenerator heat transfer fluid in loop 146, flows. Each panel assembly 214 also includes liquid desiccant channels on opposite sides of the heat transfer fluid channels. Liquid desiccant, such as concentrated liquid desiccant 152 or diluted liquid desiccant 154 in the liquid desiccant loop 108, flows through the liquid desiccant channels. The liquid desiccant flowing through the liquid desiccant channels is separated from the heat transfer fluid flowing through the heat transfer fluid channels of the corresponding panel assembly, and heat is exchanged between the liquid desiccant in the liquid desiccant channels and the heat transfer fluid flowing through the heat transfer fluid channels. An air flow gap 216, also referred to as an air gap 216, is defined in the lateral direction between adjacent panel assemblies 214. Each air flow gap 216 extends mainly in the vertical direction and the longitudinal direction.

[0052] Any suitable number of panel assemblies 214 may be included in the three-way heat exchanger 200. For example, the three-way heat exchanger 200 may include from 1 to 200 panel assemblies 214, from 1 to 100 panel assemblies 214, from 50 to 200 panel assemblies 214, from 50 to 100 panel assemblies 214, such as one panel assembly, ten panel assemblies 214, twenty panel assemblies 214, thirty panel assemblies 214, forty panel assemblies 214, fifty panel assemblies 214, sixty panel assemblies 214, seventy panel assemblies 214, eighty panel assemblies 214, ninety panel assemblies 214, 100 panel assemblies 214, or more than 100 panel assemblies 214.

[0053] The panel assemblies 214 are supported on a base 240 at a second vertical side 212 of the three-way heat exchanger 200. The panel assemblies 214 extend substantially parallel to each other between the base 240 and a first vertical side 210 of the three-way heat exchanger 200. In an exemplary operation of the three-way heat exchanger 200, the panel assemblies 214 may deviate from the substantially parallel range when fluid flows through the panel assemblies 214 and / or when air flows through an air gap 216 between adjacent panel assemblies 214. The base 240 includes a liquid desiccant reservoir (as Figure 4 and Figure 5 shown) adjacent to the air flow outlet 226 at a second longitudinal side 208 and a second vertical side 212. The liquid desiccant reservoir extends longitudinally outwardly beyond the panel assemblies 214, and a liquid desiccant mist trap may be used to collect liquid desiccant entrained in and subsequently removed from the air flow at the air flow outlet 226. For example, the liquid desiccant mist trap is described in U.S. Patent Application No. 18 / 391,384 (docket number 38902-391, COP-23-073US01) titled "LIQUID DESICCANT AIR CONDITIONER MODULES HAVING A LIQUID DESICCANT MIST TRAP" filed on December 20, 2023, the entire disclosure of which is incorporated by reference.

[0054] The three-way heat exchanger 200 includes a first end plate 218 and a second end plate 220 located at a first lateral side 202 and a second lateral side 204, respectively. The end plates 218, 220 may also be referred to as end caps or end sheets. The end plates 218 and 220 may provide lateral support for the set of panel assemblies 214 and enclose the interior 222 of the three-way heat exchanger 200 at the first lateral side 202 and the second lateral side 204. Figure 3 and Figure 5The end plates 218 and 220 are omitted to more clearly show the arrangement of the panel assemblies 214, the air flow gaps 216 defined between adjacent panel assemblies 214, and the interior 222 of the three-way heat exchanger 200.

[0055] Each of the end plates 218 and 220 includes alignment apertures 258 and 260 respectively, which are adapted to receive a clamping assembly (not shown) for clamping the panel assemblies 214 together. Example clamping assemblies suitable for use in the three-way heat exchanger 200 are described in U.S. Patent Application No. 18 / 490,984, filed on October 20, 2023, the entire disclosure of which is incorporated herein by reference.

[0056] The interior 222 of the three-way heat exchanger 200 can be enclosed by the set of panel assemblies 214 at the first vertical side 210 and the second vertical side 212 of the three-way heat exchanger. For example, adjacent panel assemblies 214 can be connected to and / or in contact with each other at opposite vertical ends to seal the respective air flow gaps 216 defined therebetween at the opposite vertical ends and to enclose the interior 222 of the three-way heat exchanger at the first vertical side 210 and the second vertical side 212. Additionally and / or alternatively, the three-way heat exchanger 200 can include vertical end plates (not shown) to enclose the interior 222 at the first vertical side 210 and the second vertical side 212.

[0057] The three-way heat exchanger 200 includes an air flow inlet 224 on the first longitudinal side 206 and an air flow outlet 226 on the second longitudinal side 208. The air flow inlet 224 and the air flow outlet 226 are defined by the longitudinal side panels 228 and 230 of the three-way heat exchanger 200 respectively. For example, the longitudinal side panels 228 and 230 can include openings in the form of grilles or grille openings, baffles, louvers, dampers, or can have any other suitable opening configuration to allow air flow to enter into and exit from the three-way heat exchanger 200. In some examples, one or both of the longitudinal side panels 228 and 230 can include filters to filter particles and / or contaminants from the air flow processed by the three-way heat exchanger 200. The air flow inlet 224 and the air flow outlet 226 communicate with the air flow gaps 216 defined between adjacent panel assemblies 214, and allow an inlet air flow (e.g., Figure 1 the first inlet air flow 110 or the second inlet air flow 114 in Figure 2 ) to flow horizontally in the longitudinal direction through the three-way heat exchanger 200 in the air flow direction (indicated by the arrow 278 in Figure 3 andFigure 5 The longitudinal side panels 228 and 230 are omitted to more clearly show the arrangement of the panel assembly 214, the air flow gap 216 defined between adjacent panel assemblies 214, and the interior 222 of the three-way heat exchanger 200.

[0058] The three-way heat exchanger 200 further includes a heat transfer fluid inlet 232, a heat transfer fluid outlet 234, a liquid desiccant inlet 236, and a liquid desiccant outlet 238. The heat transfer fluid (e.g., circulating in one of the heat transfer fluid loops 138 or 146 in Figure 1 enters and exits the three-way heat exchanger 200 via the heat transfer fluid inlet 232 and the heat transfer fluid outlet 234, respectively. The liquid desiccant (e.g., circulating in the liquid desiccant loop 108 in Figure 1 enters and exits the three-way heat exchanger 200 via the liquid desiccant inlet 236 and the liquid desiccant outlet 238, respectively. The positions of the heat transfer fluid inlet 232, the heat transfer fluid outlet 234, the liquid desiccant inlet 236, and the liquid desiccant outlet 238 may vary according to the desired flow directions of the heat transfer fluid and the liquid desiccant through the panel assembly 214. The liquid desiccant inlet 236 and the heat transfer fluid outlet 234 may be defined (e.g., integrally formed) by the end plate 218, and the liquid desiccant outlet 238 and the heat transfer fluid inlet 232 may be defined (e.g., integrally formed) by the end plate 220. Alternatively, the heat transfer fluid inlet 232, the heat transfer fluid outlet 234, the liquid desiccant inlet 236, and the liquid desiccant outlet 238 may each be defined by a conduit (e.g., a pipe, a tube, a hose, or other suitable fluid conduit) longitudinally extending through an opening in the respective end plates 218 and 220.

[0059] Referring to Figures 7 to 9 , an exemplary panel assembly 300 (also referred to as a multi-layer panel) suitable for use as a separate panel assembly 214 will now be described. In the exemplary three-way heat exchanger 200, all panel assemblies 214 have substantially the same configuration as the panel assembly 300 shown in Figures 7 to 9 . For ease of description, the panel assembly 214 will hereinafter be referred to as the panel assembly 300. Some or all of the panel assemblies in the panel assembly 214 may include additional components, fewer components, or other components compared to the panel assembly 300.

[0060] Figure 7 is a right side view of the exemplary panel assembly 300. Figure 8 is an exploded view of the panel assembly 300. Figure 9 is along Figure 7A schematic cross-section of the panel assembly 300 taken along the cross-section line 9-9 in []. The spatial relationships of the components of the panel assembly 300 will be described with respect to the X-axis, Y-axis, and Z-axis, as well as the lateral, longitudinal, and vertical directions defined by the three-way heat exchanger 200. The panel assembly 300 will also be described in the orientation when implemented and installed in the three-way heat exchanger 200. The directional terms are used only for convenience in describing the components of the panel assembly 300. The examples shown and described are not limited to any particular orientation.

[0061] The panel assembly 300 includes a frame 302 that defines a first vertical end 304 and a second vertical end 306 of the panel assembly 300 on the Z-axis, a first lateral face 305 and a second lateral face 307 on the X-axis, and a first longitudinal end 308 and a second longitudinal end 310 on the Y-axis. The frame 302 includes opposite first header sections 312 and second header sections 314 located at the first vertical end 304 and the second vertical end 306, respectively. The frame 302 further includes an intermediate section 316 between the opposite header sections 312 and 314. The header sections 312 and 314 define liquid desiccant header regions 320 and 322, respectively. The intermediate section 316 defines a heat transfer fluid region 324. The liquid desiccant header regions 320 and 322 are separated from the heat transfer fluid region 324 by (unlabeled) portions (or "frame bars") of the frame 302 that extend between the heat transfer fluid region 324 and one of the liquid desiccant header regions 320 and 322. The intermediate section 316 defines the leading edge and the trailing edge of the frame 302. The leading edge extends between the header sections 312 and 314 near the first longitudinal end 308, and the trailing edge extends between the header sections 312 and 314 near the second longitudinal end 310. The leading edge and / or the trailing edge may include aerodynamic features that facilitate controlling the pressure drop and / or reducing the resistance of the air flowing through the air flow gap 216. Exemplary aerodynamic features are described in U.S. Patent Application No. 18 / 390,941 (Docket No. 38902-389, COP-24-003US01) entitled "LIQUID DESICCANT AIR CONDITIONER MODULES HAVING AERODYNAMIC FEATURES" filed on December 20, 2023, the entire disclosure of which is incorporated herein by reference.

[0062] Each header section 312, 314 of the frame 302 includes complementary air flow restrictor members 388, 390 ( Figures 12 to 18)。The first airflow restrictor member 388 of each header section 312, 314 is located on the first lateral face 305 of the frame 302. The second airflow restrictor member 390 of each header section 312, 314 is located on the second lateral face 307 of the frame 302. When the heat exchanger 200 is assembled with the airflow gap 216 defined between adjacent panel assemblies 300, the first airflow restrictor member 388 of a panel assembly 300 mates or engages with the second airflow restrictor member 390 of an adjacent panel assembly 300 to form an airflow restrictor 392 in the airflow gap 216 located between adjacent panel assemblies (see Figures 16 to 18 ). The airflow restrictor 392 defines a tortuous path in the airflow gap 216 for the inlet air flow in a direction different from the airflow direction (e.g., the vertical direction). The liquid desiccant region 320 of the first header section 312 is located inside (e.g., vertically below) the airflow restrictor members 388, 390 of the first header section 312. The liquid desiccant region 322 of the second header section 314 is located inside (e.g., vertically above) the airflow restrictor members 388, 390 of the second header section 314. Thus, the heat transfer fluid region 324 and the two liquid desiccant header regions 320, 322 of each adjacent panel assembly 300 are located between the airflow restrictors 392 positioned in the airflow gap 216. The airflow restrictor members 388, 390 and the airflow restrictor 392 will be further described below with reference to Figures 12 to 18 .

[0063] The panel assembly 300 further includes a first plate 326 and a second plate 328 disposed on opposite side surfaces of the frame 302 that cover the intermediate section 316 of the cover frame 302. The first plate 326 and the second plate 328 are, for example, sheets of material less than 0.5 inches thick or less than 0.25 inches thick, and the plates 326, 328 may also be referred to as "heat exchange sheets" or "sheets". The first plate 326 and the second plate 328 may be attached to the frame 302 or may be integrally formed with the frame 302. Suitable techniques for attaching the plates 326 and 328 to the frame 302 may include, for example, welding (e.g., laser welding, induction welding, or radio frequency welding), adhesive bonding, thermal bonding, or another suitable technique for joining materials together. Additional details regarding attaching the plates 326 and 328 to the frame 302 are described, for example, in U.S. Patent No. 11,022,330, issued June 1, 2021, U.S. Patent No. 10,921,001, issued February 16, 2021, and U.S. Patent Application No. 18 / 390,475 (Docket No. 38902-387, COP-23-074US01), filed December 20, 2023, entitled "SYSTEMS AND METHODS FOR ASSEMBLING LIQUID DESICCANT AIRCONDITIONER PANELS USING FLEXIBLE ALIGNMENT FEATURES", the entire disclosures of which are incorporated by reference.

[0064] The frame 302 and the plates 326 and 328 may be made of different but compatible materials for welding together. For example, the frame 302 and the plates 326 and 328 may each be made of the same or different thermoplastic or polymeric materials. The frame 302 may be made of a thermoplastic or polymer, for example, using an injection molding process. The plates 326, 328 may be made of a thermoplastic or polymer, for example, using a thermoforming process and / or by die cutting. The materials for the frame 302 and the plates 326 and 328 may also be selected based on their compatibility with the liquid desiccant used in the three-way heat exchanger 200. Suitable polymeric materials for the frame 302 and the plates 326 and 328 include, for example, polyolefins (e.g., polypropylene and / or polyethylene), acrylonitrile butadiene styrene (ABS), and combinations thereof. The plates 326 and 328 may include additives that improve properties such as laser absorption and conductivity, as well as the strength and / or stiffness of the plates 326 and 328. In other examples, the frame 302 and the plates 326 and 328 may be made of any other suitable materials that enable the three-way heat exchanger 200 to function as described.

[0065] The sheets or plates 326 and 328 enclose and seal the heat transfer fluid region 324 of the frame, thereby defining a heat transfer fluid passage 330 of the panel assembly 300 between the plates 326 and 328 (see Figure 9 ). As described below, in an exemplary operation of the three-way heat exchanger 200, the heat transfer fluid flows between the plates 326 and 328 through the heat transfer fluid passage 330, and the liquid desiccant flows on the outer surfaces of the plates 326 and 328 opposite to the heat transfer fluid passage 330. The plates 326 and 328 isolate the liquid desiccant from the heat transfer fluid in the passage 330 and allow heat to be transferred between the liquid desiccant and the heat transfer fluid. The plates 326 and 328 may extend over one or both of the liquid desiccant header regions 320 and 322 and define openings (e.g., orifices 360) aligned with one or both of the liquid desiccant header regions 320 and 322 to enable the liquid desiccant to flow therethrough. In the exemplary panel assembly 300, each of the plates 326 and 328 includes a series of orifices 360 positioned adjacent to the liquid desiccant header 320 and a series of orifices 362 positioned adjacent to the liquid desiccant header region 322. The liquid desiccant may flow through the orifices 360 and 362 of each of the plates 326 and 328 to enter and / or leave the liquid desiccant header regions 320 and 322, respectively.

[0066] A mesh or perforations (not shown) may be provided in the heat transfer fluid passage 330 to maintain the width of the heat transfer fluid passage under negative pressure. The mesh or perforations may also promote a more constant flow rate of the heat transfer fluid through the passage 330. The mesh or perforations may also help to improve the flow distribution of the heat transfer fluid between the panel assemblies 300 in the three-way heat exchanger 200. The mesh or perforations may also provide turbulence of the heat transfer fluid to increase heat transfer with the liquid desiccant flowing on the outer surfaces of the sheets or plates 326 and 328. A variety of materials may be used for the mesh or perforations. For example, the mesh or perforations may include the same polymeric material as the plate (e.g., polyolefin, ABS, or a combination thereof). Alternatively, flow guides (not shown) may be provided in the heat transfer fluid passage 330. Exemplary flow guides are described in U.S. Patent Application No. 18 / 585,344, filed on February 23, 2024, entitled "THREE-WAY HEAT EXCHANGE MODULE WITH CONTROLLED FLUID FLOW" (Docket No. 38902-413; COP-23-049US01), the entire disclosure of which is incorporated herein by reference.

[0067] Referring again to Figures 7 to 9, the panel assembly 300 further includes membranes 332 and 334 disposed on opposite side faces 305 and 307 of the frame 302. In other examples, only one of the membranes 332 or 334 may be included in the panel assembly 300. The membranes 332 and 334 cover the outer surfaces of the sheets or plates 326 and 328. As Figure 9 shown, liquid desiccant channels 336 and 338 are respectively defined between the membrane 332 and the plate 326 and between the membrane 334 and the plate 328. The membranes 332 and 334 also encapsulate and seal the liquid desiccant manifold regions 320 and 322. Each of the liquid desiccant channels 336 and 338 fluidly connects the liquid desiccant manifold regions 320 and 322. As described below, in an exemplary operation of the three-way heat exchanger 200, liquid desiccant flows through one of the liquid desiccant manifold regions 320 or 322, enters the liquid desiccant channels 336 and 338, above the outer surfaces of the plates 326 and 328 and behind the membranes 332 and 334, and finally enters the other of the liquid desiccant manifold regions 320 or 322. The plates 326 and 328 limit the contact between the liquid desiccant flowing in the liquid desiccant channels 336 and 338 and the heat transfer fluid flowing through the heat transfer fluid channels 330, and enable heat transfer therebetween. In examples where only one of the membranes 332 or 334 is included in the panel assembly 300, only one liquid desiccant channel 336 or 338 may be defined between the membrane 332 or 334 and the plate 326 or 328. In these examples, the plates 326 or 328 on the side faces 305 or 307 opposite the liquid desiccant channels 336 or 338 may encapsulate and seal the liquid desiccant manifold regions 320 and 322, and limit the flow of the liquid desiccant opposite the liquid desiccant channels 336 or 338.

[0068] Membranes 332 and 334 are respectively attached to one of the lateral faces 305 and 307 of the frame 302 to encapsulate and seal the liquid desiccant manifold regions 320 and 322. Membranes 332 and 334 can additionally and / or alternatively be attached to the outer surfaces of the respective sheets or plates 326 and 328, which can help maintain the width of the liquid desiccant channels 336 and 338 and / or limit the tendency of membranes 332 and 334 to bulge outward as liquid desiccant flows through the liquid desiccant channels 336 and 338. Membranes 332 and 334 can be attached to the lateral faces 305 and 307 of the frame 302 and / or the outer surfaces of the plates 326 and 328 using any suitable technique such as, for example, adhesive bonding, heat sealing, or welding. Membranes 332 and 334 can be directly attached to plates 326 and 328 respectively by heat sealing or welding, where compatible materials (e.g., polyolefins) are used for membranes 332 and 334 and the respective plates 326 and 328. An outer adhesive layer (not shown) can be applied to the outer surfaces of plates 326 and 328 to improve the quality or ease of forming a heat seal or weld with the respective membranes 332 and 334. The outer surfaces of plates 326 and 328 can include raised patterns or dot features (not shown) to which membranes 332 and 334 adhere, heat seal, or otherwise attach. The raised patterns can be formed on the frame 302 and / or plates 326 and 328 by thermoforming, embossing, or other suitable techniques. Attaching membranes 332 and 334 to the dot features or raised patterns can provide the additional advantage of promoting the uniform distribution of liquid desiccant across the liquid desiccant channels 336 and 338 in the longitudinal direction and reducing the stresses that can cause warping of plates 326 and 328. Warping of plates 326 and 328 can reduce the ability to transfer heat and moisture between the heat transfer fluid, the liquid desiccant, and the air flowing through membranes 332 and 334 during an exemplary operation of the three-way heat exchanger 200. Additional details regarding example systems and methods for attaching membranes 332 and 334 to the frame 30 and the respective sheets or plates 326 and 328 are described in, for example, U.S. Patent No. 11,022,330, issued June 1, 2021, U.S. Patent No. 10,921,001, issued February 16, 2021, and U.S. Patent Application No. 18 / 390,475 (docket number 38902-387, COP-23-074US01), filed December 20, 2023, entitled "SYSTEMS AND METHODS FOR ASSEMBLING LIQUID DESICCANT AIR CONDITIONER PANELS USING FLEXIBLE ALIGNMENT FEATURES", the entire disclosures of which are incorporated herein by reference.

[0069] The membranes 332 and 334 are made of a vapor-permeable material that allows water vapor to pass therethrough such that the liquid desiccant flowing in the liquid desiccant channels 336 and 338 can absorb moisture from the air flowing through the membranes 332 and 334 and desorb water into the air flowing through the membranes 332 and 334. In some examples, the membranes 332 and 334 can each be made of a polypropylene material or other suitable vapor-permeable polymeric material. The vapor-permeable material for the membranes 332 and 334 can be microporous (e.g., having a pore size less than 0.5 micrometers (μm)). Examples of suitable microporous membranes are disclosed in U.S. Patent No. 9,101,874, which was published on August 11, 2015, the entire disclosure of which is incorporated herein by reference. By way of example, suitable commercially available membranes include the EZ2090 polypropylene microporous membrane from Celgard. The microporous membranes 332 and 334 can have an open area of 40% to 80%, a pore size less than 0.5 μm, and a thickness less than 100 μm. Some example microporous membranes can have an open area greater than 80%. One suitable membrane has an open area of about 65% and a thickness of about 20 μm. The pore size of this type of membrane is very uniform structurally and is thin enough not to create a significant thermal barrier. Other possible membranes include membranes from 3M, Lydall, and other manufacturers. The membranes 332 and 334 can include any suitable vapor-permeable material that allows water to pass therethrough such that the liquid desiccant in the liquid desiccant channels 336 and 338 can absorb moisture from the air flowing past the membranes 332 and 334 or desorb water into the air flowing past the membranes 332 and 334.

[0070] The frame 302 defines a liquid desiccant inlet port 340 for supplying liquid desiccant into the liquid desiccant manifold region 320 and a liquid desiccant outlet port 342 for receiving liquid desiccant from the liquid desiccant manifold region 322. The liquid desiccant inlet port 340 is defined in the first corner flange 364 of the frame 302. The first corner flange 364 of the frame 302 is part of the first manifold section 312 and is positioned adjacent to the liquid desiccant manifold region 320 and the second longitudinal end 310 at the first vertical end 304 of the panel assembly 300. The liquid desiccant outlet port 342 is defined in the second corner flange 366 of the frame 302. The second corner flange 366 is part of the second manifold section 314 and is positioned adjacent to the liquid desiccant manifold region 322 and the first longitudinal end 308 at the second vertical end 306 of the panel assembly 300. Thus, the first corner flange 364 and the second corner flange 366 and the liquid desiccant inlet port 340 and the liquid desiccant outlet port 342 defined therein, respectively, are located on opposite longitudinal and vertical ends of the panel assembly 300.

[0071] As represented by Figure 7 and Figure 9 the flow lines 344 in, in an exemplary operation of the tee heat exchanger 200, liquid desiccant is supplied via the liquid desiccant inlet port 340 into the liquid desiccant manifold region 320 of the panel assembly 300, flows through each of the liquid desiccant channels 336 and 338 and into the liquid desiccant manifold region 322, and exits the panel assembly 300 via the liquid desiccant outlet port 342. In the illustrated example, the liquid desiccant flows vertically downward in the desiccant channels 336, 338. The liquid desiccant may have an alternative flow direction. The flow direction of the liquid desiccant in the channels 336, 338 may vary depending on, for example, the orientation of the panel assembly 300 in the heat exchanger 200, the positions of the liquid desiccant inlet port 340 and the liquid desiccant outlet port 342, and / or which liquid desiccant manifold region 320, 322 the liquid desiccant is supplied to and from which manifold region the liquid desiccant exits.

[0072] The frame 302 also defines a heat transfer fluid inlet port 346 that supplies heat transfer fluid into the heat transfer fluid channel 330 and a heat transfer fluid outlet port 348 that receives heat transfer fluid from the heat transfer fluid channel 330. The heat transfer fluid inlet port 346 is defined in the third corner flange 368 of the frame 302. The third corner flange 368 of the frame 302 is part of the second manifold section 314 and the intermediate section 316. The third corner flange 368 is positioned adjacent to the heat transfer fluid channel 330 at the second longitudinal end 310 of the panel assembly 300 and near the second vertical end 306. The heat transfer fluid outlet port 348 is defined in the fourth corner flange 370 of the frame 302. The fourth corner flange 370 is part of the first manifold section 312 and the intermediate section 316. The fourth corner flange 370 is positioned adjacent to the heat transfer fluid channel 330 at the first longitudinal end 308 of the panel assembly 300 and near the first vertical end 304. Thus, the third corner flange 368 and the fourth corner flange 370 and the heat transfer fluid inlet port 346 and the heat transfer fluid outlet port 348 defined therein, respectively, are located on opposite longitudinal and vertical ends of the panel assembly 300. Additionally, the first corner flange 364 and the fourth corner flange 370 and the liquid desiccant inlet port 340 and the heat transfer fluid outlet port 348 defined therein, respectively, are both positioned near the first vertical end 304 on opposite longitudinal ends of the panel assembly. The second corner flange 366 and the third corner flange 368 and the liquid desiccant outlet port 342 and the heat transfer fluid inlet port 346 defined therein, respectively, are both positioned near the second vertical end 306 on opposite longitudinal ends of the panel assembly.

[0073] As byFigure 7 and Figure 9 As represented by flow line 350 in Figure 9 , in an exemplary operation of the three-way heat exchanger 200, the heat transfer fluid is supplied via the heat transfer fluid inlet port 346 into the heat transfer fluid passage 330 of the panel assembly 300, flows therethrough, and exits the panel assembly 300 via the heat transfer fluid outlet port 348. In the illustrated example, the heat transfer fluid flows vertically upward in the passage 330. The heat transfer fluid may have an alternative flow direction. The flow direction of the heat transfer fluid in the passage 330 may vary depending on, for example, the orientation of the panel assembly 300 in the heat exchanger 200, the positions of the heat transfer fluid inlet port 346 and the heat transfer fluid outlet port 348, and / or which port 346, 348 the heat transfer fluid enters the passage 330 through and which port it exits the passage 330 through.

[0074] Figures 10A to 10D are respectively Figure 8 enlarged views of portions A, B, C, and D of the frame 302 shown, and more particularly depict the corner flanges 364 to 370. In particular, Figures 10A to 10D shown are the microchannels or orifices that provide fluid connections between the ports 340, 342, 346, and 348 defined in the panel assembly 300 and the corresponding fluid regions. As Figure 10A and Figure 10B shown in Figure 10A and Figure 10B , the heat transfer fluid inlet port 346 is connected to the heat transfer fluid region 324 through the orifice 352 ( Figure 10B ), and the heat transfer fluid outlet port 348 is connected to the heat transfer fluid region 324 through the orifice 354 ( Figure 10A ). The heat transfer fluid region 324 defines the heat transfer fluid passage 330 when sealed to the opposite lateral faces 305 and 307 of the frame 302 by the plates 326 and 328. As indicated by the flow line 350 in Figure 10A and Figure 10B Figure 9 , the heat transfer fluid enters the heat transfer fluid passage 330 from the inlet port 346 via the orifice 352 and exits the passage 330 via the orifice 354 into the outlet port 348.

[0075] As Figure 10C and Figure 10D shown in Figure 10C and Figure 10D , the liquid desiccant inlet port 340 is connected to the first liquid desiccant manifold region 320 through the orifice 356 ( Figure 10C ) and the liquid desiccant outlet port 342 is connected to the second liquid desiccant manifold region 322 through the orifice 358 ( Figure 10D ). As indicated by Figure 10C and Figure 10DAs indicated by the flow line 344 in, the liquid desiccant enters the first liquid desiccant header region 320 from the inlet port 340 via the orifice 356, flows into and through the liquid desiccant channels 336 and 338 ( Figure 9 ), enters the second liquid desiccant header region 322, and leaves the header region 322 via the orifice 358 and enters the outlet port 342. In Figures 10A to 10D the illustrated example, each of the orifices 352 to 358 includes two orifices. Any suitable number of orifices may be used for the orifices 352 to 358. In some examples, a greater number of orifices may be used for some of the orifices 352 to 358 than for other orifices 352 to 358. The number, size, and / or shape of the orifices 352 to 358 may be the same or different. The number, size, and shape of the orifices used for each of the orifices 352 to 358 may also vary between the panel assemblies 300.

[0076] Figures 10A to 10D Also shown are exemplary features of the panel assembly 300 that may facilitate connecting adjacent panel assemblies 300 when installed in the three-way heat exchanger 200. For example, when the panel assemblies 300 are arranged in series and installed in the heat exchanger 200, the corner flanges 364 to 370 of the frames 302 of adjacent panel assemblies 300 may be connected. As shown, each of the corner flanges 364 to 370 includes one or more snap fittings 372. The snap fittings 372 extend laterally from the first lateral face 305 of the frame 302, and the corresponding holes 374 ( Figure 6 shown in) penetrate into the second lateral face 307 at a position laterally opposite to the snap fittings 372. In the illustrated example, each of the corner flanges 364 to 370 includes two snap fittings 372 and corresponding holes 374. In other examples, more or fewer snap fittings 372 and corresponding holes 374 may be included at the corner flanges 364 to 370. The corner flanges 364 to 370 may include the same or different numbers of snap fittings 372 and corresponding holes 374. Appropriately, for each snap fitting 372 in each of the corner flanges 364 to 370, a corresponding hole 374 is included. When the panel assemblies 300 are arranged in series and installed in the heat exchanger 200, each snap fitting 372 of the corner flanges 364 to 370 of the frame 302 of one of the panel assemblies 300 is received by one of the corresponding holes 374 of the corner flanges 364 to 370 of the frame 302 of the laterally adjacent panel assembly 300 to directly connect the adjacent panel assemblies 300.

[0077] Each of the corner flanges 364 to 370 also includes one or more alignment holes 376 extending therethrough in a lateral direction. In the illustrated embodiment, each of the corner flanges 364 to 370 includes two alignment holes 376, which are labeled as a first alignment hole 376a and a second alignment hole 376b in Figures 10A to 10D . The first alignment hole 376a of each of the corner flanges 364 to 370 is located longitudinally inward of the second alignment hole 376b and adjacent to the corresponding corner of the heat transfer fluid region 324. In other examples, more or fewer alignment holes 376 may be included at the corner flanges 364 to 370. The corner flanges 364 to 370 may include the same or different numbers of alignment holes 376. When the panel assemblies are arranged in series and installed in the heat exchanger 200, the alignment holes 376 of the corner flanges 364 to 370 of the frame 302 of the panel assembly 300 receive corresponding clamping assemblies (not shown) for clamping the panel assemblies 300 together. The first alignment hole 376a of the panel assembly 300 corresponds to one of the alignment openings 258 of the first end plate 218 and one of the alignment openings 260 of the second end plate 220 ( Figure 2 and Figure 4 as shown). The second alignment hole 376b receives a corresponding clamping assembly (not shown). The second alignment hole 376b does not correspond to the alignment openings 258 and 260 in the end plates 218 and 220, such that the clamping assembly received by the second alignment hole 376b extends through the panel assembly 300 but does not extend through the end plates 218 and 220.

[0078] Still referring to Figures 10A to 10D, each of the corner flanges 364 to 370 includes a flange collar 378 that surrounds a respective fluid port 340, 342, 346, 348 defined in the corner flange. The flange collar 378 extends in a lateral direction from a first lateral face 305 of the frame 302. Each corner flange 364 to 370 also includes a corresponding grooved nozzle 380 that projects into the second lateral face 307 and surrounds the respective fluid port 340, 342, 346, 348 at a position laterally opposite to the flange collar 378. When the panel assemblies 300 are arranged in series and installed in the heat exchanger 200, each flange collar 378 of the corner flanges 364 to 370 of the frame 302 of one panel assembly 300 in the panel assemblies 300 is received by one of the grooved nozzles 380 of the corresponding corner flanges 364 to 370 of the frame 302 of the laterally adjacent panel assembly 300 to directly connect the adjacent panel assemblies 300. Each flange collar 378 includes a set of guide teeth 382 that facilitate alignment of the flange collar 378 with the corresponding grooved nozzle 380 and insertion of the flange collar 378 into the grooved nozzle 380. The guide teeth 382 may include guiding features (e.g., chamfers) for more easily inserting the teeth and the flange collar 378 into the corresponding grooved nozzle 380. An elastomeric seal (not shown), such as an O-ring, may be seated within each of the grooved nozzles 380, and when the flange collar 378 is inserted into the grooved nozzle 380, a fluid-tight seal is formed at the adjacent fluid ports 340, 342, 346, 348 between the adjacent panel assemblies 300.

[0079] Also refer to Figure 3 and Figure 5 and shows a left view of a three-way heat exchanger 200 similar to Figure 3 and Figure 5 with various components omitted Figure 6 , the panel assemblies 300 are arranged in sequence or in series in the lateral direction as described above. In Figure 3 , Figure 5 and Figure 6For ease of illustration, the plates 326 and 328 and the membranes 332 and 334 are omitted. When assembled and installed in the three-way heat exchanger 200, for each pair of adjacent panel assemblies 300, the membrane 332 of one panel assembly in the panel assemblies 300 faces the membrane 334 of the other panel assembly in the panel assemblies 300. An air flow gap 216 is defined between the adjacent membranes 332 and 334. Each panel assembly 300 may have a reduced width at the intermediate section 316 such that the panel assemblies 300 are spaced apart at their adjacent intermediate sections 316 to define the air flow gap 216. Additionally and / or alternatively, the air flow gap 216 may be defined and maintained by supports or spacers 386 between the intermediate sections 316 of the adjacent panel assemblies 300. The supports or spacers 386 extend outwardly in the lateral direction from the intermediate sections 316 near the longitudinal ends 308 and 310. The intermediate section 316 of each frame 302 may additionally and / or alternatively include snap fittings 372 and corresponding holes 374 (as Figure 6 and Figure 7 shown) near the longitudinal ends 308 and 310. The snap fittings 372 and the corresponding holes 374 located on the intermediate section 316 of the frame 302 may facilitate connecting adjacent panel assemblies 300 at adjacent intermediate sections. In addition to the spacers 386, snap fittings 372 and corresponding holes 374 may also be included. Alternatively, in some examples, the spacer 386 may be a snap fitting 372 that engages the holes 374 of the adjacent panel assemblies 300 to connect the adjacent panel assemblies and maintain the width of the air flow gap 216.

[0080] The panel assemblies 300 are arranged in the three-way heat exchanger 200 such that for each panel assembly, the first lateral face 305 and the second lateral face 307 of the frame 302 are respectively oriented towards the first lateral side 202 and the second lateral side 204 of the three-way heat exchanger 200. The first longitudinal end 308 and the second longitudinal end 310 are respectively located at the first longitudinal side 206 and the second longitudinal side 208 of the three-way heat exchanger 200, and the first vertical end 304 and the second vertical end 306 are respectively located at the first vertical side 210 and the second vertical side 212 of the three-way heat exchanger 200. The leading edge of the frame 302 located near the first longitudinal end 308 is close to the air inlet 224. The trailing edge of the frame 302 near the second longitudinal end 310 is close to the air outlet 226.

[0081] The ports 340, 342, 346, and 348 of the panel assembly 300 are aligned to define respective manifolds of the three-way heat exchanger 200 that extend in a lateral direction, through which heat transfer fluid and liquid desiccant flow into and out of the panel assembly 300 between the first lateral side 202 and the second lateral side 204. The liquid desiccant inlet port 340 of the panel assembly 300 is aligned to form a liquid desiccant inlet manifold 242 that extends between the first lateral side 202 and the second lateral side 204 adjacent to the first vertical side 210 and the second longitudinal side 208 of the three-way heat exchanger 200. The liquid desiccant outlet port 342 of the panel assembly 300 is aligned to form a liquid desiccant outlet manifold 244 that extends between the first lateral side 202 and the second lateral side 204 adjacent to the second vertical side 212 and the first longitudinal side 206 of the three-way heat exchanger 200. The heat transfer fluid inlet port 346 of the panel assembly 300 is aligned to form a heat transfer fluid inlet manifold 246 that extends between the first lateral side 202 and the second lateral side 204 adjacent to the second vertical side 212 and the second longitudinal side 208 of the three-way heat exchanger 200. The heat transfer fluid outlet port 348 of the panel assembly 300 is aligned to form a heat transfer fluid outlet manifold 248 that extends between the first lateral side 202 and the second lateral side 204 adjacent to the first vertical side 210 and the first longitudinal side 206 of the three-way heat exchanger 200.

[0082] The panel assembly 300 may include O-rings or other elastomeric sealing members that form a fluid-tight seal between the aligned ports 340, 342, 346, and 348 of adjacent panel assemblies to prevent fluid leakage from the respective manifolds 242 to 248. For example, as described above, an elastomeric seal (not shown), such as an O-ring, may be seated within each of the slotted nozzles 380, and when the flange collar 378 is inserted into the slotted nozzle 380, a fluid-tight seal is formed at the adjacent fluid ports 340, 342, 346, 348 between adjacent panel assemblies 300. In some examples, the elastomeric seal 384 is a radial seal (e.g., a radial O-ring seal). Additionally, within each of the corner flanges 364 to 370, the snap fittings 372, corresponding holes 374, and alignment holes 376 collectively surround the fluid ports 340, 342, 346, 348 defined in the corner flanges, which may assist in creating and maintaining a fluid-tight seal between the adjacent ports 340, 342, 346, 348 that define the manifolds 242 to 248.

[0083] As Figure 3 and Figure 5As shown in, conduits 250, 252, 254, and 256 are used to fluidly connect the heat transfer fluid inlet 232 and outlet 234, and the liquid desiccant inlet 236 and outlet 238 to the respective manifolds for allowing the heat transfer fluid and the liquid desiccant to enter and exit the three-way heat exchanger 200. The liquid desiccant inlet 236 is fluidly connected to the liquid desiccant inlet manifold 242 through conduit 250. The liquid desiccant outlet 238 is fluidly connected to the liquid desiccant outlet manifold 244 through conduit 252. The heat transfer fluid inlet 232 is fluidly connected to the heat transfer fluid inlet manifold 246 through conduit 254. The heat transfer fluid outlet 234 is fluidly connected to the heat transfer fluid outlet manifold 248 through conduit 256. Conduits 250 through 256 can include any suitable fluid conduits (rigid and / or flexible) that enable the heat transfer fluid and the liquid desiccant to flow between the respective inlets and outlets and the manifolds, including, for example but not limited to, pipes, hoses, tubes, and combinations thereof. Each of conduits 250 through 256 can be attached to the respective manifolds 242 through 248 by coupling an end of the conduit to an appropriate one of the ports 340, 342, 346, and 348 in the port plate assembly 300 (i.e., the port plate assembly 300 adjacent to the lateral sides 202 or 204). Conduits 250 through 256 can be attached to the appropriate ports 340, 342, 346, and 348 of the port plate assembly 300 using any suitable means - including fasteners, threads, clamps, etc.

[0084] Conduits 250 and 256 extend between the end plate 218 and the port plate assembly 300 at the first lateral side 202. Conduits 252 and 254 extend between the end plate 220 and the port plate assembly 300 at the second lateral side 204. Conduits 250 and 256 can extend through the end plate 218 to respectively define the inlet 236 or outlet 234, can be coupled to the respective inlet 236 or outlet 234 defined by the end plate 218, or can be integrally formed with the end plate 218 and the respective inlet 236 or outlet 234 defined by the end plate 218. Conduits 252 and 254 can extend through the end plate 220 to respectively define the outlet 238 or inlet 232, can be coupled to the respective outlet 238 or inlet 232 defined by the end plate 220, or can be integrally formed with the end plate 220 and the respective outlet 238 or inlet 232 defined by the end plate 220.

[0085] Each of the manifolds 242 to 248 may be closed at a lateral side 202 or 204 of the heat exchanger 200 opposite the inlet or outlet to which the manifold is connected. The liquid desiccant inlet manifold 242 may be closed at the second lateral side 204, the liquid desiccant outlet manifold 244 may be closed at the first lateral side 202 opposite the liquid desiccant inlet manifold 242, the heat transfer fluid inlet manifold 246 may be closed at the first lateral side 202, and the heat transfer fluid outlet manifold 248 may be closed at the second lateral side 204 opposite the heat transfer fluid inlet manifold 246. The manifolds 242 to 248 may be closed at the respective lateral sides 202 or 204 by end plates 218 or 220 ( Figure 2 and Figure 4 as shown). In particular, the end plate 218 may block the ports 342 and 346 of the panel assembly 300 at an end of the panel assembly 300 adjacent to the first lateral side 202 to close the manifolds 244 and 246 at the first lateral side 202. The end plate 220 may block the ports 340 and 348 of the panel assembly 300 at an end of the panel assembly 300 adjacent to the second lateral side 204 to close the manifolds 244 and 246 at the second lateral side 204. Additionally and / or alternatively, end caps or plugs 272 and 274 (see Figure 11 ) may be inserted into or otherwise disposed over the ports 342 and 346 of the panel assembly 300 adjacent to the first lateral side 202 to close the manifolds 244 and 246 at the first lateral side 202, and end caps or plugs 270 and 276 (see Figure 11 ) may be inserted into or otherwise disposed over the ports 340 and 348 of the panel assembly 300 adjacent to the second lateral side 204 to close the manifolds 244 and 246 at the second lateral side 204.

[0086] Now referring to Figure 11 , the operation of the three-way heat exchanger 200 will now be described. Figure 11 is a schematic view showing an internal view of the three-way heat exchanger 200 to depict the flow of liquid desiccant and heat transfer fluid through the manifolds 242 to 248 and the panel assembly 300. In the schematic view of Figure 11 , for ease of illustration and description, the panel assembly 300 is depicted as having exaggerated and / or simplified features.

[0087] In an exemplary operation of the heat exchanger 200, an inlet air stream (e.g., Figure 1The first inlet air stream 110 or the second inlet air stream 114 (shown in []) enters through the air flow inlet 224 and flows in the air flow direction 278 through the air gap 216 defined between adjacent panel assemblies 300. The air flowing through the air gap 216 is directed through the liquid desiccant indicated by the flow line 344 and the heat transfer fluid indicated by the flow line 350 of each panel assembly in the panel assembly 300. In some operations, the liquid desiccant 344 is the concentrated liquid desiccant 152 from the liquid desiccant loop 108, and the heat transfer fluid 350 is from Figure 1 the regulator heat transfer fluid of the regulator subsystem 104 shown in [], and the heat exchanger 200 is used to cool and dehumidify the air flowing through the air gap 216. In other operations, the liquid desiccant 344 is the diluted liquid desiccant 154 from the liquid desiccant loop 108, and the heat transfer fluid 350 is from Figure 1 the regenerator heat transfer fluid of the regenerator subsystem 106 shown in [], and the heat exchanger 200 is used to heat the moisture and discharge the moisture into the air flowing through the air gap 216.

[0088] The liquid desiccant 344 flows from the first lateral side 202 to the liquid desiccant inlet manifold 242 via the liquid desiccant inlet 236 and the conduit 250 (shown in Figures 3 to 5 []). The liquid desiccant 344 enters the liquid desiccant header region 320 of each panel assembly 300 from the liquid desiccant inlet manifold 242 via the orifice 356. In each panel assembly 300, the liquid desiccant 344 flows from the liquid desiccant header region 320, enters the liquid desiccant channels 336 and 338 via the orifices 360 (shown in Figure 7 and Figure 8 []) on each of the plates 326 and 328, flows downward through the liquid desiccant channels 336 and 338, and enters the liquid desiccant header region 322 via the orifices 362 (shown in Figure 7 and Figure 8 []) on each of the plates 326 and 328. When the liquid desiccant 344 flows behind the membranes 332 and 334 of the panel assembly 300, the liquid desiccant 344 absorbs moisture from the air flowing through the air gap 216 adjacent to the membranes 332 and 334 or desorbs water into the air. Permitting moisture to permeate through each of the membranes 332 and 334 enables the transfer of moisture between the liquid desiccant 344 and the air in the air gap 216. The liquid desiccant 344 that has absorbed or desorbed moisture exits each panel assembly 300 via the orifice 358 from the corresponding liquid desiccant header region 322 and flows toward the second lateral side 204 through the liquid desiccant outlet manifold 244. The liquid desiccant 344 flows via the conduit 252 and the liquid desiccant outlet 238 (shown in Figure 5as shown in FIG. ) exits the heat exchanger 200.

[0089] The heat transfer fluid 350 flows from the second lateral side 204 into the heat transfer fluid inlet manifold 246 via the heat transfer fluid inlet 232 and conduit 254 ( Figure 4 and Figure 5 as shown in FIG.). The heat transfer fluid 350 enters each panel assembly 300 from the heat transfer fluid inlet manifold 246 via the orifice 352. In each panel assembly 300, the heat transfer fluid 350 flows upward through the heat transfer fluid channels 330. The heat transfer fluid 350 flowing through the channels 330 is in thermal communication with the liquid desiccant 344 flowing through the liquid desiccant channels 336 and 338. Depending on the operating mode of the heat exchanger 200, heat is transferred between the heat transfer fluid 350 and the liquid desiccant 344 to remove heat from the air flowing through the air gap 216 or to discharge heat into the air flowing through the air gap 216. The heat transfer fluid 350 that has absorbed or discharged heat exits each panel assembly 300 via the orifice 354 and flows toward the first lateral side 202 through the heat transfer fluid outlet manifold 248. The heat transfer fluid 350 exits the heat exchanger 200 via the conduit 256 and the heat transfer fluid outlet 234 ( Figures 3 to 5 as shown in FIG.).

[0090] In the illustrated embodiment, the flow directions of the heat transfer fluid 350 and the liquid desiccant 344 are shown by way of example only and may be changed in other embodiments of the heat exchanger 200. For example, the liquid desiccant 344 may flow upward through the desiccant channels 336 and 338 on the panel assembly 300. In these examples, the directions of flow of the liquid desiccant 344 through the liquid desiccant inlet 236 and the liquid desiccant outlet 238 and the liquid desiccant inlet manifold 242 and the liquid desiccant outlet manifold 244 will also be reversed. The heat transfer fluid 350 may flow downward through the heat transfer channels 330 of the panel assembly 300. In these examples, the directions of flow of the heat transfer fluid 350 through the heat transfer fluid inlet 232 and the heat transfer fluid outlet 234 and the heat transfer fluid inlet manifold 246 and the heat transfer fluid outlet manifold 248 will also be reversed. In the illustrated example, the liquid desiccant 344 and the heat transfer fluid 350 flow in a countercurrent relationship, but in alternative examples may flow through the panel assembly in the same direction.

[0091] The inlet air flow entering via the air flow inlet 224 is distributed into the air flow gap 216, flows through the air flow gap 216 along the air flow direction 278, and exits via the air flow outlet 226. The air flow may have a tendency to leak from the air flow gap 216 in a direction different from the air flow direction 278 (e.g., in the vertical direction between adjacent header sections 320 and / or adjacent header sections 322 of the adjacent panel assemblies 300). This may have a negative impact on the performance and / or efficiency of the heat exchanger 200. For example, air leakage between the panel assemblies may reduce the output of conditioned air leaving the heat exchanger 200. Leakage can be prevented by placing end plates above and / or below the panel assemblies 300 to vertically enclose the interior 222 of the heat exchanger 200. However, a portion of the air flow in the air flow gap 216 can still flow through areas of the panel assemblies where the heat transfer fluid and the liquid desiccant do not flow (e.g., above and / or below the heat transfer fluid channels 330 and the desiccant channels 336, 338 in the vertical direction). This allows for "dead zones" in the air flow gap 216 where the air contacts the "non-working" areas of the panel assemblies 300, thereby reducing the efficiency of the heat exchanger 200. Additionally and / or alternatively, using separate end plates above and / or below the panel assemblies 300 to prevent air leakage may increase the material and labor costs associated with the manufacture and / or assembly of the heat exchanger 200.

[0092] Referring to Figures 12 to 18, two air flow limiters 392 are located in each air flow gap 216 between a pair of adjacent panel assemblies 300 to define a curved path for the inlet air flow in the air flow gap 216 in a direction different from the air flow direction (e.g., in the vertical direction). The air flow limiters 392 facilitate reducing, suppressing, or eliminating the tendency of the inlet air flow to leak between the adjacent panel assemblies 300. Thereby, the output of the processed (e.g., conditioned) air flowing along the air flow direction through the air flow outlet 226 of the heat exchanger 200 can be optimized. The air flow limiters 392 are "sandwiched" between the adjacent panel assemblies 300 and are located at opposite ends (e.g., opposite vertical ends) of the air flow gap 216. The air flow limiters 392 are positioned outside (e.g., vertically above or below) the heat transfer fluid channels 330 and the desiccant channels 336 and 338 of the adjacent panel assemblies 300, which reduces any negative interference that the air flow limiters 392 may have on the contact between the air flow and the working area of the panel assemblies 300. The air flow limiters 392 extend along the air flow direction 278 (e.g., the longitudinal direction), one air flow limiter 392 extends near the first vertical end 304 of the adjacent panel assembly 300, and one air flow limiter 392 extends near the second vertical end 306 of the adjacent panel assembly 300. The air flow limiters 392 can extend in a shape complementary to the arrangement of the working components (e.g., manifolds 242 and 248 and header regions 320, or manifolds 244 and 246 and header regions 322) of the header sections 312, 314 so as to minimize the clearance space between the working area of the panel assemblies 300 and the air flow limiters 392. This can reduce any "dead zones" in the air flow gap 216 and optimize the surface area contact between the air flow and the working area of the panel assemblies 300.

[0093] Each air flow limiter 392 is formed between two adjacent panel assemblies 300 by the engagement or mating between a first air flow limiter member 388 on each header section 312, 314 of one adjacent panel assembly ("first" panel assembly) of the adjacent panel assemblies 300 and a second air flow limiter member 390 on each header section 312, 314 of the other adjacent panel assembly ("second" panel assembly) of the adjacent panel assemblies 300. The first air flow limiter member 388 is shown in Figure 12 and the second air flow limiter member 390 is shown in Figure 13 . Figure 12A and Figure 12B are respectively Figure 12 enlarged views of regions 12A and 12B in Figure 13A which more clearly show the first air flow limiter member 388. Figure 13B and Figure 13An enlarged view of regions 13A and 13B therein, which more particularly shows the second airflow limiter member 390.

[0094] The first airflow limiter member 388 is located on the first lateral face 305 of the frame 302, and there is one first airflow limiter member 388 on each of the header sections 312, 314. The first airflow limiter member 388 projects laterally from the lateral face 305 of the frame 302, and each first airflow limiter member defines a ridge 394 that extends between the first longitudinal end 308 and the second longitudinal end 310 of the frame 302. The ridge 394 is a convex mating element for forming the airflow limiter 392, and the first airflow limiter member 388 may also be referred to as the convex airflow limiter member 388. The longitudinal extent of the ridge 394 on the first header section 312 is shaped such that the ridge 394 extends adjacent to and vertically above each of the fourth corner flange 370, the liquid desiccant header region 320, and the first corner flange 364. The longitudinal extent of the ridge 394 on the second header section 314 is shaped such that the ridge 394 extends adjacent to and vertically below each of the second corner flange 366, the liquid desiccant header region 322, and the third corner flange 368. The longitudinal extent of the ridge 394 may be such that the ridge is vertically very close to the respective liquid desiccant header regions 320, 322 and the respective corner flanges 364 to 370 to minimize the vertical gap between the working area of the panel assembly and the first airflow limiter member 388 while preventing the first airflow limiter member from interfering with the liquid desiccant header regions 320, 322 and the corner flanges 364 to 370.

[0095] The second airflow limiter member 390 is located on the second lateral face 307 of the frame 302, and there is one second airflow limiter member 390 on each of the header sections 312, 314. The second airflow limiter member 390 projects laterally from the lateral face 307 of the frame 302, and each second airflow limiter member defines a valley 396 that extends between the first longitudinal end 308 and the second longitudinal end 310 of the frame 302. The second airflow limiter member 390 is located on the second lateral face 307 at a corresponding position to the first airflow limiter member 388 on the first lateral face 305. The valley 396 is a concave mating element for forming the airflow limiter 392, and the valley 396 is sized and shaped to receive the corresponding ridge 394. The second airflow limiter member 390 may also be referred to as the concave airflow limiter member 390. The longitudinal extent of the valley 396 on the first header section 312 corresponds to the longitudinal extent of the ridge 394 on the first header section, and is shaped such that the valley 396 extends adjacent to and vertically above each of the fourth corner flange 370, the liquid desiccant header region 320, and the first corner flange 364. The longitudinal extent of the valley 396 on the second header section 314 corresponds to the longitudinal extent of the ridge 394 on the second header section, and is shaped such that the valley 396 extends adjacent to and vertically below each of the second corner flange 366, the liquid desiccant header region 322, and the third corner flange 368. Similar to the ridge 394, the longitudinal extent of the concave valley 396 may be such that the valley is vertically very close to the respective liquid desiccant header regions 320, 322 and the respective corner flanges 364 to 370 to minimize the vertical gap between the working area of the panel assembly and the second airflow limiter member 388, while preventing the second airflow limiter member from interfering with the liquid desiccant header regions 320, 322 and the corner flanges 364 to 370.

[0096] The airflow restrictor members 388, 390 and the frame 302 can be integrally formed from a single material, such as a polymeric material or a thermoplastic material (e.g., a polyolefin such as polypropylene and / or polyethylene). For example, the airflow restrictor members 388, 390 and the frame 302 can be integrally formed from a thermoplastic or polymeric material using injection molding. Integrally manufacturing the airflow restrictor members 388, 390 and the frame 302 from a single material can provide additional advantages of material and cost savings during the manufacture of the frame 302. Alternatively, the airflow restrictor members 388, 390 can be components attached to the frame 302 at corresponding positions on the first header section 310 and the second header section 312. In these examples, the airflow restrictor members 388, 390 can be attached to the frame 302 by welding, adhesive bonding, thermal bonding, solid-state attachment (e.g., ultrasonic welding) or another suitable technique for joining materials together.

[0097] Referring Figure 14 , Figure 14 is a front view of the frame 302 alone, where the width or thickness (measured along the X-axis between the lateral faces 305, 307) of the frame 302 at the intermediate section 316 is reduced relative to the width or thickness at the header sections 312, 314. The reduced width of the intermediate section 316 allows adjacent panel assemblies 300 to be laterally spaced apart on their adjacent intermediate sections 316 to define an airflow gap 216. The relatively greater thickness of the frame 302 at the header sections 312, 314 allows adjacent panel assemblies 300 to be connected (e.g., via corner flanges 364 to 370) at their adjacent header sections 312, 314. For example, as described above with reference to Figures 10A to 10D , the corner flanges 364 to 370 include connectors (e.g., snap fittings 372 and corresponding holes 374, alignment holes 376 for receiving clamping assemblies, and / or flange collars 378 and corresponding slotted nozzles 380) for connecting adjacent panel assemblies 300.

[0098] The airflow gap 216 defined by the reduced thickness of the intermediate sections 316 of the adjacent panel assemblies 300 can be maintained by a support or spacer 386 that extends laterally between the intermediate sections 316 of the adjacent panel assemblies 300. As Figure 12 and Figure 14 shown, the spacer 386 is positioned on opposite longitudinal sides of the heat transfer fluid region 324 near the two longitudinal ends 308, 310 of the frame 302 in a vertical arrangement. In this example, the spacer 386 extends laterally from the first lateral face 305 of the frame 302. In other examples, the spacer 386 can additionally and / or alternatively extend laterally from the second lateral face 307 of the frame 302. A joining member 387 corresponding to the spacer 386 ( Figure 13As shown, it can be located on the opposite side surface (in this example, the side surface 307). The engaging member 387 can receive the spacer 386 of the adjacent frame 302 and enable the spacer 386 to function as described. The spacer 386 can be the snap fitting 372 described above, and the engaging member 387 can be the corresponding hole 374.

[0099] Figure 15 is a front view of the three frames 302 of the three panel assemblies 300, and the three frames 302 are shown positioned when the heat exchanger 200 is assembled. Figure 15 Only the adjacent frames 302 are shown, and for ease of illustration and description, the plates 326, 328 and the membranes 332, 334 are omitted. An air flow gap 216 is defined between the adjacent intermediate sections 316 of the adjacent panel assemblies 300. Each pair of adjacent header sections 312, 314 is connected using connectors (e.g., snap fittings 372 and corresponding holes 374, alignment holes 376 for receiving the clamping assembly, and / or flange collars 378 and corresponding slotted nozzles 380) located on the corner flanges 364 to 370 described with reference to Figures 10A to 10D The width of the air flow gap 216 is maintained using spacers 386 located between each pair of adjacent intermediate sections 316.

[0100] Figure 16 and Figure 17 are respectively Figure 15Cross-sections of regions 16 and 17 are shown, and an air flow restrictor 392 formed between each pair of adjacent header sections 312 and each pair of adjacent header sections 314 is shown. Two air flow restrictors 392 are formed between the first frame 302a and the second frame 302b, one air flow restrictor 392 is located between adjacent header sections 312, and one air flow restrictor 392 is located between adjacent header sections 314. Each air flow restrictor 392 formed between the first frame 302a and the second frame 302b is formed by the engagement between a first air flow restrictor member 388 of the first frame 302a and a second air flow restrictor member 390 of the second frame 302b. Specifically, the ridge 394 of the first frame 302a is received by the valley 396 of the second frame 302b, thereby forming the air flow restrictor 392 that creates a tortuous path for the air in the air flow gap 216 in a direction different from the air flow direction 278 (e.g., in the vertical direction). Two air flow restrictors 392 are also formed between the second frame 302b and the third frame 302c, one air flow restrictor 392 is located between adjacent header sections 312, and one air flow restrictor 392 is located between adjacent header sections 314. Each air flow restrictor 392 formed between the second frame 302b and the third frame 302c is similarly formed by the engagement between a first air flow restrictor member 388 of the second frame 302b and a second air flow restrictor member 390 of the third frame 302c. Specifically, the ridge 394 of the second frame 302b is received by the valley 396 of the third frame 302c, thereby forming the air flow restrictor 392 that creates a tortuous path for the air in the air flow gap 216 in a direction different from the air flow direction 278 (e.g., in the vertical direction). The two air flow restrictors 392 in each air flow gap 216 are located at opposite ends (e.g., opposite vertical ends) of the air flow gap 216 and facilitate preventing the air flow from flowing through the air flow gap in a direction not intended for the air flow direction 278 (e.g., thereby preventing air from leaking vertically through adjacent panel assemblies 300). Additional restriction and / or constraint of the air flow in a direction different from the air flow direction 278 (e.g., in the vertical direction) can be provided by the T-shaped edges 398 at the vertical ends 304, 306 of the frame 302. As Figure 16 and Figure 17 shown, adjacent T-shaped edges 398 can engage and / or be very close to create an additional tortuous layer for the tortuous path created by the air flow restrictor 392.

[0101] Each air flow restrictor 392 can include one or more sealing elements 399( Figure 18As shown, one or more seal elements 399 facilitate creating a mechanical seal in addition to the tortuous path for air. The seal element 399 can be positioned between the engaged first airflow limiter member 388 and the second airflow limiter member 390. For example, the seal element 399 can be positioned in the valley 396 of the second airflow limiter member 390 and create a mechanical seal when the ridge 394 of the first airflow limiter member 388 is received in the valley 396. In some examples, the seal element 399 can be an elastomeric seal or gasket that is compressed to create a fluid-tight seal when the ridge 394 of the first airflow limiter member 388 is received in the valley 396 of the second airflow limiter member 390. In other examples, the seal element 399 can be configured to create a labyrinth seal or another suitable mechanical seal between the engaged first airflow limiter member 388 and the second airflow limiter member 390. The seal element 399 can additionally and / or alternatively be a seal created by attaching or fusing the engaged airflow limiter members 388 and 390 using suitable techniques for bonding materials together (e.g., attaching or fusing the ridge 394 received within the corresponding valley 396). For example, the engaged airflow limiter members 388 and 390 can be attached or fused by solid-state attachment (e.g., ultrasonic welding).

[0102] Figure 18 is Figure 16 Another view of the cross-section shown, in which the third frame 302c is separated from the second frame 302b. The third frame 302c is connected to the second frame 302b using connectors at the header sections 312, 314 (e.g., by inserting the snap fitting 372 of the second frame 302b into the corresponding hole 374 of the third frame 302c and / or inserting the flange collar 378 of the second frame 302b into the corresponding slotted nozzle 380 of the third frame 302b). The first airflow limiter member 388 of the second frame 302b engages (e.g., is received by) the second airflow limiter member 390 of the third frame 302b, which can facilitate aligning the frames 302b, 302c at their header sections 312, 314 and aligning the connectors for connecting the frames 302b, 302c. The first airflow limiter member 388 and the second airflow limiter member 390 can thus facilitate easier assembly of the panel assembly 300.

[0103] The engagement between the first airflow limiter member 388 and the second airflow limiter member 390 of adjacent frames 302 (e.g., frames 302a, 302b and frames 302b, 302c) can facilitate providing structure and rigidity to adjacent panel assemblies 300 during assembly. For example, each pair of engaged first airflow limiter member 388 and second airflow limiter member 390 can limit or constrain the relative movement of adjacent panel assemblies 300 in the vertical direction and / or the longitudinal direction. In some examples, the engaged first airflow limiter member 388 and second airflow limiter member 390 can allow relative lateral movement of adjacent panel assemblies 300 while constraining or limiting relative movement and / or longitudinal movement. In particular, the second airflow limiter member 390 can be appropriately sized and shaped to receive the corresponding first airflow limiter member 388 without creating friction or a press fit between the first airflow limiter member 388 and the second airflow limiter member 390. This can enable easier disassembly of the panel assembly 300 and can use separate separating components (e.g., connectors and / or spacers 386 of corner flanges 364 to 370) that are easier to disconnect to connect and maintain the spacing between adjacent panel assemblies 300. The substantially frictionless engagement between the engaged first airflow limiter member 388 and the second airflow limiter member 390 can additionally and / or alternatively allow the panel assembly 300 to expand and contract in the lateral direction at various temperatures during operation of the heat exchanger 200. In other examples, the first airflow limiter member 388 and the second airflow limiter member 390 of adjacent panel assemblies 300 can be frictionally engaged.

[0104] Figure 19An example method 400 of operating a three-way heat exchanger (e.g., three-way heat exchanger 200) is provided. Method 400 includes directing 402 a heat transfer fluid through a panel assembly 300 of the three-way heat exchanger 200. Each panel assembly includes a frame 302 that defines a heat transfer fluid passage 330 through which the heat transfer fluid is directed. Method 400 also includes directing 404 a liquid desiccant through desiccant passages 336, 338 of the panel assembly 300. The desiccant passages 336, 338 are defined between the frame 302 of the panel assembly 300 and membranes 332, 334, each of which is attached to one of the frames 302. Method 400 also includes directing 406 an inlet air flow through the three-way heat exchanger 200 along an air flow direction 278. The inlet air flow flows through an air flow gap 216 defined between adjacent panel assemblies 300. Method 400 also includes using an air flow restrictor 392 positioned in the air flow gap 216 to restrict 408 (or constrain) the flow of air directed through the three-way heat exchanger in a direction different from the air flow direction 278. The air flow direction 278 may be a horizontal direction (e.g., a longitudinal direction), and restricting 408 the flow of air in a direction not used for the air flow direction may include using air flow restrictors 392 located at opposite vertical ends of each air flow gap 216 to restrict the flow of air in the vertical direction. Method 400 may also include maintaining the width of each air flow gap 216 while directing air through the three-way heat exchanger using spacers 386 positioned in each air flow gap 216, where the spacers 386 are separate from the air flow restrictors 392.

[0105] The example systems and methods described include a three-way heat exchanger operable to remove heat and moisture from an air stream and / or discharge heat and moisture into an air stream. The three-way heat exchanger can include a panel assembly through which a heat transfer fluid and a liquid desiccant are directed, and an air flow gap defined between adjacent panel assemblies for directing air therethrough along an air flow direction. Example panel assemblies of the three-way heat exchanger include a frame, two sheets attached to the frame to define a heat transfer fluid channel, and membranes attached to each sheet to define a desiccant channel. An air flow restrictor is positioned in each air flow gap between adjacent panel assemblies and facilitates restricting or preventing air flow in a direction other than the air flow direction. For example, air can flow horizontally through the heat exchanger, and the air flow restrictors can be located at opposite vertical ends of the air flow gap to restrict or prevent air from leaking vertically through adjacent panel assemblies. The air flow restrictor can be formed by engagement of an air flow restrictor member of each panel assembly with an air flow restrictor member of an adjacent panel assembly. Engagement between the air flow restrictor members can also facilitate easier assembly by aligning connectors for connecting adjacent panel assemblies and / or providing structure and rigidity to adjacent panel assemblies, such as by restricting relative movement of adjacent panel assemblies to facilitate easier assembly. In some examples, the air flow restrictor member and the frame are integrally formed from one material, which can reduce material and manufacturing costs and additionally facilitate easier manufacture and assembly of the panel assembly.

[0106] Embodiments of HVAC systems and methods of operating the systems have been described in detail above. The systems and methods are not limited to the specific embodiments described herein, but rather, components of the systems and methods can be used independently and separately from other components described herein. For example, the systems and methods described herein can be used in systems other than HVAC systems.

[0107] When introducing elements of the present disclosure or embodiments thereof, the articles “a,” “an,” “the,” and “said” are intended to mean that there is one or more of the elements. The terms “comprising,” “including,” “containing,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. The use of terms indicating a particular orientation (e.g., “top,” “bottom,” “side,” “vertical,” “lateral,” “longitudinal,” etc.) is for ease of description and does not require any particular orientation of the item being described.

[0108] The terms “about,” “substantially,” “essentially,” and “approximately” and their equivalents, when used in conjunction with a range of dimensions, concentrations, temperatures, or other physical or chemical properties or characteristics, mean to encompass variations that may exist in the upper and / or lower limits of the range of the property or characteristic, including, for example, variations caused by rounding, measurement methods, or other statistical variations.

[0109] Since various changes can be made to the above-described configurations and methods without departing from the scope of the present disclosure, all the content included in the above description and shown in the drawings should be construed as illustrative and not in a limiting sense.

Claims

1. A three-way heat exchanger operable to transfer heat between a heat transfer fluid, a liquid desiccant and air, the three-way heat exchanger comprising: an air flow inlet and an air flow outlet; as well as The panel assemblies are arranged to have airflow gaps defined between adjacent panel assemblies to allow air to flow between the airflow inlet and the airflow outlet in an airflow direction, each panel assembly comprising: a frame including two header sections and an intermediate section extending between the header sections, the intermediate section defining a heat transfer fluid passage; a membrane positioned on the frame and defining a desiccant channel; and two air flow restrictor members positioned at each header section of the frame, wherein for each header section, a first air flow restrictor member is located on a first face of the frame and a second air flow restrictor member is located on a second face of the frame; wherein, for each pair of adjacent panel assemblies, the intermediate sections of the adjacent panel assemblies are spaced apart to define the airflow gap, and the first airflow restrictor member of the first panel assembly engages the second airflow restrictor member of the second panel assembly to form two airflow restrictors in the airflow gap, and wherein the airflow restrictors are located at opposite ends of the airflow gap relative to a direction different from the airflow direction.

2. The three-way heat exchanger according to claim 1, wherein: For each panel assembly, the first airflow restrictor member defines a ridge extending on the first side of the frame, and the second airflow restrictor member defines a valley located on the second side of the frame, and wherein, for each pair of adjacent panel assemblies, the ridge defined by the first airflow restrictor member of the first panel assembly is received by the valley defined by the second airflow restrictor member of the second panel assembly to form two of the airflow restrictors.

3. The three-way heat exchanger according to claim 1, wherein: Each air flow restrictor defines a tortuous path for air flowing in the direction different from the air flow direction.

4. The three-way heat exchanger according to claim 1 defines a lateral direction, a longitudinal direction and a vertical direction perpendicular to each other, wherein: The panel assembly is arranged along the lateral direction, the air flow direction is in the longitudinal direction, and the two air flow restrictors are located at opposite ends of the air flow gap with respect to the vertical direction.

5. The three-way heat exchanger according to claim 1, wherein: For each pair of adjacent panel assemblies, the header sections of the adjacent panel assemblies are connected using connectors separate from the airflow restrictor member.

6. The three-way heat exchanger according to claim 1, wherein: For each header section of each frame of each panel assembly, the header section includes a liquid desiccant header area connected to the desiccant channel of the panel assembly, and the liquid desiccant header area is located on the inner side of the first airflow restrictor member and the second airflow restrictor member relative to the direction different from the airflow direction.

7. The three-way heat exchanger according to claim 1, wherein: For each panel assembly, the first airflow restrictor member, the second airflow restrictor member and the frame are integrally formed from one material.

8. The three-way heat exchanger according to claim 7, wherein: For each panel assembly, the first air flow restrictor member, the second air flow restrictor member and the frame are integrally formed from an injection molded polymer material.

9. The three-way heat exchanger according to claim 1, wherein: The engagement between the first air flow restrictor member and the second air flow restrictor member provides rigidity to the adjacent panel assembly.

10. The three-way heat exchanger according to claim 1, wherein: Each air flow restrictor includes a sealing element positioned between the first air flow restrictor component and the second air flow restrictor component.

11. The three-way heat exchanger according to claim 10, wherein: The sealing element is an elastomeric seal.

12. A three-way heat exchanger for transferring heat between a heat transfer fluid, a liquid desiccant and air, the three-way heat exchanger defining a lateral direction, a longitudinal direction and a vertical direction perpendicular to each other, the three-way heat exchanger comprising: an air flow inlet and an air flow outlet; The panel assemblies are arranged in the lateral direction to have air flow gaps defined between adjacent panel assemblies to allow air to flow between the air flow inlet and the air flow outlet along the longitudinal direction, each panel assembly comprising: a frame defining a heat transfer fluid passage; and a membrane positioned on the frame and defining a desiccant channel; and Two air flow restrictors, the air flow restrictors are located in each air flow gap between each pair of adjacent panel assemblies, wherein each air flow restrictor defines a tortuous path for air to flow along the vertical direction, and wherein, for each pair of adjacent panel assemblies, one of the air flow restrictors is vertically positioned above the heat transfer fluid channel and the desiccant channel, and the other of the air flow restrictors is vertically positioned below the heat transfer fluid channel and the desiccant channel.

13. The three-way heat exchanger according to claim 12, wherein: Each pair of adjacent panel assemblies is connected using a connector separate from the airflow restrictor.

14. The three-way heat exchanger according to claim 12, wherein: A spacer is positioned between each pair of adjacent panel assemblies, the spacer being spaced apart from the airflow restrictor, wherein the spacer operates to maintain a width of the airflow gap.

15. The three-way heat exchanger according to claim 12, characterized in that: Each panel assembly includes a middle section defining the heat transfer fluid channel and two header sections located at opposite vertical ends of the middle section, wherein each header section includes a first airflow restrictor member located on a first side of the frame and a second airflow restrictor member located on a second side of the frame, and wherein, for each pair of adjacent panel assemblies, the middle sections of the adjacent panel assemblies are spaced apart to define the airflow gap, and the first airflow restrictor member of the first panel assembly engages the second airflow restrictor member of the second panel assembly to form two of the airflow restrictors.

16. The three-way heat exchanger according to claim 15, wherein: For each header section of each frame of each panel assembly, the header section includes a liquid desiccant header area connected to the desiccant channel of the panel assembly and located vertically inboard of the first and second air flow restrictor components.

17. The three-way heat exchanger according to claim 15, wherein: For each panel assembly, the first airflow restrictor member, the second airflow restrictor member and the frame are integrally formed from one material.

18. A method of operating a three-way heat exchanger, the method comprising: a panel assembly for directing a heat transfer fluid through the three-way heat exchanger, wherein each panel assembly includes a frame defining a heat transfer fluid passage through which the heat transfer fluid is directed; directing a liquid desiccant through a desiccant passage of the panel assembly, the desiccant passage being defined between the frame of the panel assembly and a membrane attached to the frame; directing air through the three-way heat exchanger in an airflow direction, wherein the air flows through airflow gaps defined between adjacent panel assemblies; and An airflow restrictor positioned in the airflow gap is used to restrict the flow of air directed through the three-way heat exchanger in a direction different from the airflow direction.

19. The method according to claim 18, wherein: The airflow direction is a horizontal direction, and restricting the flow of air in the direction not used for the airflow direction includes restricting the flow of air in a vertical direction using the airflow restrictor.

20. The method of claim 18, further comprising maintaining the width of each airflow gap while directing air through the three-way heat exchanger using a spacer located in each airflow gap, wherein The spacer is separate from the air flow restrictor.

Images