Heat exchanger and method of operating heat exchanger

Abstract

The invention relates to a heat exchanger and a method of operating a heat exchanger. The heat exchanger is operable to condition the air using a liquid desiccant. The heat exchanger includes an airflow inlet, an airflow outlet, a heat exchange structure positioned between the airflow inlet and the airflow outlet, and a mesh screen positioned at the airflow outlet. Each heat exchange structure has a surface for the flow of a liquid desiccant. The screen selectively removes entrained liquid desiccant from the air.

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, the 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 then 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 it 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 operation of the 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 the condensation stage, where 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 in providing the reader with background information to facilitate a better understanding of the 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 heat exchanger capable of operating to condition air using a liquid desiccant. The heat exchanger includes an air flow inlet, an air flow outlet, a heat exchange structure positioned between the air flow inlet and the air flow outlet, and a screen positioned at the air flow outlet. Each heat exchange structure has a surface for the flow of the liquid desiccant. The screen selectively removes entrained liquid desiccant from the air.

[0008] Another aspect is a heat exchanger capable of operating to condition air using a liquid desiccant. The heat exchanger includes an air flow inlet, an air flow outlet, a heat exchange structure positioned between the air flow inlet and the air flow outlet, and a screen positioned at the air flow outlet. Each heat exchange structure has a surface for the flow of the liquid desiccant. The screen is removably connected to the heat exchange structure.

[0009] Another aspect is a method of operating a heat exchanger. The method includes: guiding air through the heat exchanger, wherein the air flows through the air flow inlet of the heat exchanger, an air flow gap defined between adjacent heat exchange structures of the heat exchanger, and the air flow outlet of the heat exchanger in an air flow direction; guiding a liquid desiccant to each of the heat exchange structures in the heat exchanger, wherein the liquid desiccant flows over the surface of each heat exchange structure; and selectively removing entrained liquid desiccant from the air using a screen positioned at the air flow outlet.

[0010] There are various improvements to the features noted in the above aspects. Other features may also be incorporated in the above aspects. These improvements and additional features may exist alone or in any combination. For example, the various features discussed below with respect to any of the illustrated embodiments may 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 front perspective view of a three-way heat exchanger in the HVAC system of

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

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

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

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

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

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

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

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

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

[0022] Figure 12 is another rear perspective view of the three-way heat exchanger, in which, similar to Figure 5 , various components are omitted, and a liquid desiccant mist eliminator is positioned at the air flow outlet of the heat exchanger.

[0023] Figure 13 is Figure 7 separate right front view of the frame of the panel assembly of

[0024] Figure 14AAnd Figure 14B are respectively Figure 13 enlarged views of regions 14A and 14B shown.

[0025] Figure 15 is a perspective view of an exemplary liquid desiccant mist eliminator.

[0026] Figure 16 is Figure 15 an exploded view of the mist eliminator.

[0027] Figure 17 is for connecting Figure 15 and Figure 16 of the mist eliminator to a heat exchanger as shown in Figure 12 a separate perspective view of a coupler.

[0028] Figure 18 is Figure 17 a right front view of the coupler.

[0029] Figure 19 is a cross-section of the coupler taken along line 19-19 in Figure 17 .

[0030] Figures 20 to 23 is a photograph depicting the sequence of steps for assembling a liquid desiccant mist eliminator in a three-way heat exchanger.

[0031] Figure 24 is an exploded view of another exemplary liquid desiccant mist eliminator.

[0032] Figure 25 is an exemplary method of operating a heat exchanger.

[0033] Throughout the drawings, corresponding reference numerals indicate corresponding components. DETAILED DESCRIPTION

[0034] 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 may be referred to herein as air handling subsystems 104 and 106. The HVAC system 100 may include additional components or other components in addition to those shown and described with reference to Figure 1 .

[0035] 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 exiting 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 conditioning subsystem 104 to the refrigerant subsystem 102 and ultimately to the regenerator subsystem 106. The regenerator subsystem 106 transfers the heat into the second inlet air stream 114 and directs the heated outlet air stream 116 to the atmosphere.

[0036] 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. 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 components or other components in addition to those shown and described with reference to Figure 1 those shown and described.

[0037] 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 exits 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 exiting 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 exits 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 exiting the compressor 122 and the low-pressure gaseous refrigerant 128 entering the compressor 122. AsFigure 1 As shown, the flow direction of the refrigerant through 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.

[0038] 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, ethylene glycol-based fluid, or any combination of water and 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 both 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 flowing 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 those shown and described. For example, the regulator subsystem 104 may include one or more pumps (not shown) that 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.

[0039] In an example operation of the regulator subsystem 104, the regulator heat transfer fluid in loop 138 is directed towards 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 flowing refrigerant 134 in loop 126 to produce gaseous refrigerant 128. The cooled regulator heat transfer fluid 140 exiting the evaporator 118 is directed towards 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 exiting the first three-way heat exchanger 136 is directed back to the evaporator 118, and the process is repeated.

[0040] 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 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.

[0041] 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.

[0042] HVAC system 100 also includes a liquid desiccant loop 108 that operates in conjunction with subsystems 102 to 106 to condition a first inlet air stream 110 through latent and sensible cooling. The liquid desiccant loop 108 includes a liquid desiccant that is routed between a first three-way heat exchanger 136 and a second three-way heat exchanger 144. Suitable liquid desiccants that may 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.

[0043] The liquid desiccant loop 108 may include one or more pumps (not shown) for routing the liquid desiccant between the first three-way heat exchanger 136 and the second three-way heat exchanger 144. Suitable pumps that may 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 may include one or more pumps for transferring the liquid desiccant from the second heat exchanger 144 toward the first heat exchanger 136, and one or more pumps for transferring the diluted liquid desiccant 154 from the first heat exchanger 136 toward the second heat exchanger 144.

[0044] The concentrated liquid desiccant 152 in the liquid desiccant loop 108 is routed toward 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 exiting the first three-way heat exchanger 136 may have a lower humidity and / or a lower temperature than the first inlet air stream 110. The liquid desiccant that has absorbed moisture from the first inlet air stream 110 exits the first three-way heat exchanger 136 as the diluted liquid desiccant 154.

[0045] The diluted liquid desiccant 154 is directed towards 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. Accordingly, the heated outlet air stream 116 exiting the second three-way heat exchanger 144 has a greater humidity and a higher temperature compared to 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.

[0046] The liquid desiccant loop 108 may further include a desiccant-desiccant heat exchanger 156 for transferring 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 function 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 capacity 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 in-line 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.

[0047] Thus, in an example mode of operation of 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 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, which uses concentrated liquid desiccant 152 to remove moisture from the inlet air stream 110. 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.

[0048] HVAC system 100 may 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, so 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, so that the air handling subsystems 104 and 106 switch their corresponding 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 so 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, one of the air handling subsystems 104 and 106 can be idle or omitted from the HVAC system 100 according to the operating requirements and the desired set point temperature and humidity levels in the conditioned space. For example, according to 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. according to the operating mode of the HVAC system 100.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 may be referred to as the "height", the dimension along the Y-axis may be referred to as the "length", and the dimension along the X-axis may 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 may also be referred to herein as the lateral axis, the Y-axis may also be referred to herein as the longitudinal axis, and the Z-axis may also be referred to herein as the vertical axis. 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.

[0053] 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 of the panel assemblies 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.

[0054] The three-way heat exchanger 200 may include any suitable number of panel assemblies 214. 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.

[0055] 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 example 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 280 (as Figure 4 and Figure 5 shown) adjacent to an air flow outlet 226 at a second longitudinal side 208. The liquid desiccant reservoir 280 extends longitudinally outwardly beyond the panel assemblies 214. The liquid desiccant reservoir 280 may use a liquid desiccant mist eliminator 400 (as Figure 12 shown) to collect liquid desiccant entrained in the air flow and subsequently removed from the air flow at the air flow outlet 226. The liquid desiccant mist eliminator 400 is described in more detail below.

[0056] 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 an 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 5 The end plates 218 and 220 are omitted to more clearly show the arrangement of the panel assemblies 214, an air flow gap 216 defined between adjacent panel assemblies 214, and an interior 222 of the three-way heat exchanger 200.

[0057] Each end plate 218 and 220 respectively includes alignment apertures 258 and 260 for receiving a clamping assembly (not shown) for clamping the panel assembly 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.

[0058] 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 airflow gaps 216 defined therebetween at the opposite vertical ends and 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.

[0059] The three-way heat exchanger 200 includes an air inlet 224 on the first longitudinal side 206 and an air outlet 226 on the second longitudinal side 208. The air inlet 224 and the air outlet 226 are respectively defined by the longitudinal side panels 228 and 230 of the three-way heat exchanger 200. 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 inlet 224 and the air outlet 226 communicate with the airflow 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 (e.g.,) through the three-way heat exchanger 200 in the airflow direction (indicated by the arrow 278 in Figure 3 and Figure 5 The longitudinal side panels 228 and 230 are omitted to more clearly show the arrangement of the panel assemblies 214, the airflow gaps 216 defined between adjacent panel assemblies 214, and the interior 222 of the three-way heat exchanger 200.

[0060] The three-way heat exchanger 200 also includes a heat transfer fluid inlet 232 and a heat transfer fluid outlet 234, as well as 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 and the heat transfer fluid outlet 234, as well as the liquid desiccant inlet 236 and the liquid desiccant outlet 238, can 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 can be defined (e.g., integrally formed therewith) by the end plate 218, and the liquid desiccant outlet 238 and the heat transfer fluid inlet 232 can be defined (e.g., integrally formed therewith) by the end plate 220. Alternatively, the heat transfer fluid inlet 232 and the heat transfer fluid outlet 234, as well as the liquid desiccant inlet 236 and the liquid desiccant outlet 238, can 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.

[0061] 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.

[0062] Figure 7 FIG. is a right side view of the exemplary panel assembly 300. Figure 8 FIG. is an exploded view of the panel assembly 300. Figure 9 FIG. 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, Y, and Z axes and 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. 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 specific orientation.

[0063] 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 along the Z-axis, a first lateral face 305 and a second lateral face 307 along the X-axis, and a first longitudinal end 308 and a second longitudinal end 310 along 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 portions (not labeled) (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, filed on December 20, 2023, entitled "LIQUID DESICCANT AIR CONDITIONER MODULES HAVING AERODYNAMIC FEATURES" (Docket No. 38902-389, COP-24-003US01), the entire disclosure of which is incorporated herein by reference. Each header section 312, 314 of the frame 302 includes complementary air flow restrictor members (not labeled) that cooperate or engage with the air flow restrictor members of an adjacent panel assembly 300 when the heat exchanger 200 is assembled to form an air flow restrictor in the air flow gap 216 located between adjacent panel assemblies at opposite vertical ends.An air flow restrictor is described in U.S. Patent Application No. 18 / 390,948, filed on December 20, 2023, entitled "LIQUID DESICCANT AIRCONDITIONER MODULES HAVING INTERLOCKING PANELS FOR CONTROLLING AIRFLOW", (Docket No. 38902-390, COP-24-001US01), the entire disclosure of which is incorporated herein by reference.

[0064] The panel assembly 300 further includes a first plate 326 and a second plate 328 disposed on opposite lateral faces of the frame 302 that cover an intermediate section 316 of the 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. For example, additional details regarding attaching the plates 326 and 328 to the frame 302 are described in U.S. Patent No. 11,022,330, issued on June 1, 2021, U.S. Patent No. 10,921,001, issued on February 16, 2021, and U.S. Patent Application No. 18 / 390,475, filed on December 20, 2023, entitled "SYSTEMS AND METHODS FOR ASSEMBLING LIQUID DESICCANT AIRCONDITIONER PANELS USING FLEXIBLE ALIGNMENT FEATURES" (Docket No. 38902-387, COP-23-074US01), the entire disclosure of which is incorporated by reference.

[0065] The frame 302, as well as the plates 326 and 328, can be made of different but compatible materials for welding together. For example, the frame 302, as well as the plates 326 and 328, can each be made of the same or different thermoplastic or polymeric materials. The frame 302 can be made of a thermoplastic or polymer, for example, using an injection molding process. The plates 326, 328 can be made of a thermoplastic or polymer, for example, using a thermoforming process and / or by die cutting. The materials for the frame 302, as well as the plates 326 and 328, can 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, as well as 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 can 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, as well as the plates 326 and 328, can be made of any other suitable materials that enable the three-way heat exchanger 200 to function as described.

[0066] 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 through the heat transfer fluid passage 330 between the plates 326 and 328, and the liquid desiccant flows on the outer surfaces of the plates 326 and 328 opposite 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 can extend over one or both of the liquid desiccant manifold regions 320 and 322 and define openings (e.g., orifices 360) that are aligned with one or both of the liquid desiccant manifold regions 320 and 322 to enable the liquid desiccant to flow therethrough. In an exemplary panel assembly 300, each of the plates 326 and 328 includes a series of orifices 360 positioned adjacent to the liquid desiccant manifold 320 and a series of orifices 362 positioned adjacent to the liquid desiccant manifold region 322. The liquid desiccant can flow through the orifices 360 and 362 of each of the plates 326 and 328 to enter and / or leave the liquid desiccant manifold regions 320 and 322, respectively.

[0067] A mesh or perforation (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 perforation may also promote a more constant flow rate of the heat transfer fluid through the passage 330. The mesh or perforation 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 perforation 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 perforation. For example, the mesh or perforation may comprise the same polymeric material as the plates (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.

[0068] Referring again to Figures 7 to 9 , the panel assembly 300 also includes membranes 332 and 334 disposed on opposite lateral 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. In yet other examples, the membranes 332, 334 may not be included. The membranes 332 and 334 cover the outer surfaces of the sheets or plates 326 and 328. As Figure 9As shown, liquid desiccant channels 336 and 338 are defined between membrane 332 and plate 326 and between membrane 334 and plate 328, respectively. Membranes 332 and 334 also encapsulate and seal liquid desiccant manifold regions 320 and 322. Each of liquid desiccant channels 336 and 338 fluidly connects 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 liquid desiccant manifold regions 320 or 322, enters liquid desiccant channels 336 and 338, above the outer surfaces of plates 326 and 328 and behind membranes 332 and 334, and ultimately enters the other of liquid desiccant manifold regions 320 or 322. Plates 326 and 328 limit contact between the liquid desiccant flowing in liquid desiccant channels 336 and 338 and the heat transfer fluid flowing through heat transfer fluid channels 330 and enable heat transfer therebetween. In examples where only one of membranes 332 or 334 is included in the panel assembly 300, only one liquid desiccant channel 336 or 338 may be defined between membrane 332 or 334 and plate 326 or 328. In these examples, plates 326 or 328 on side faces 305 or 307 opposite liquid desiccant channels 336 or 338 may encapsulate and seal liquid desiccant manifold regions 320 and 322 and limit the flow of liquid desiccant opposite liquid desiccant channels 336 or 338. In examples where membranes 332, 334 are not included, liquid desiccant may flow "freely" over the outer surfaces of plates 326, 328 and may directly contact the air flow passing through the heat exchanger 200.

[0069] 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 may additionally and / or alternatively be attached to the outer surfaces of the respective sheets or plates 326 and 328, which may help maintain the widths 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 may 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 may be directly attached to plates 326 and 328 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) may 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 may include raised patterns or dot features (not shown) to which membranes 332 and 334 adhere, heat seal, or otherwise attach. The raised patterns may 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 may provide the additional advantage of promoting uniform distribution of liquid desiccant across the liquid desiccant channels 336 and 338 in the longitudinal direction and reducing stresses that may cause warping of plates 326 and 328. Warping of plates 326 and 328 may 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 exemplary operation of the three-way heat exchanger 200. For example, additional details regarding exemplary systems and methods for attaching membranes 332 and 334 to the frame 302 and the respective sheets or plates 326 and 328 are described 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 AIR CONDITIONER PANELS USING FLEXIBLE ALIGNMENT FEATURES", the entire disclosures of which are incorporated by reference.

[0070] 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, issued 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 in structure 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 through the membranes 332 and 334 or desorb water into the air flowing through the membranes 332 and 334.

[0071] 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.

[0072] As represented by Figure 7 and Figure 9 the flow lines 344 in, in an exemplary operation of the three-way heat exchanger 200, liquid desiccant is supplied via the liquid desiccant inlet port 340 into the liquid desiccant header region 320 of the panel assembly 300, flows through each of the liquid desiccant channels 336 and 338 and into the liquid desiccant header 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 header region 320, 322 the liquid desiccant is supplied to and from which header region the liquid desiccant exits.

[0073] The frame 302 also defines a heat transfer fluid inlet port 346 for supplying heat transfer fluid into the heat transfer fluid channel 330 and a heat transfer fluid outlet port 348 for receiving 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 header 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 header 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 ends 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.

[0074] 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 the heat transfer fluid exits the passage 330 through.

[0075] Figures 10A to 10D are respectively Figure 8 enlarged views of portions A, B, C, and D of the illustrated frame 302 and more particularly depict the corner flanges 364 to 370. In particular, Figures 10A to 10D illustrates 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 10B , 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.

[0076] 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 header region 320 through the orifice 356 ( Figure 10C ) and the liquid desiccant outlet port 342 is connected to the second liquid desiccant header 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 manifold 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 manifold region 322, and leaves the manifold 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 can be used for the orifices 352 to 358. In some examples, a greater number of orifices can 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 can be the same or different. The number, size, and shape of the orifices used for each of the orifices 352 to 358 can also vary between the panel assemblies 300.

[0077] Figures 10A to 10D Exemplary features of the panel assembly 300 that can facilitate connecting adjacent panel assemblies 300 when installed in the three-way heat exchanger 200 are also shown. 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 can 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 can be included at the corner flanges 364 to 370. The corner flanges 364 to 370 can 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.

[0078] Each of the corner flanges 364-370 also includes one or more alignment holes 376 extending therethrough in a lateral direction. In the illustrated embodiment, each of the corner flanges 364-370 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 364-370 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 364-370. The corner flanges 364-370 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 364-370 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 apertures 258 of the first end plate 218 and one of the alignment apertures 260 of the second end plate 220 ( Figure 2 and Figure 4 as shown in). The second alignment hole 376b receives a corresponding clamping assembly (not shown). The second alignment hole 376b does not correspond to the alignment apertures 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.

[0079] 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 of the corner flanges 364 to 370 also includes a corresponding slotted 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 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 in the panel assemblies 300 is received by one of the corresponding slotted nozzles 380 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. Each flange collar 378 includes a set of guide teeth 382 that facilitate aligning the flange collar 378 with the corresponding slotted nozzle 380 and inserting the flange collar 378 into the slotted 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 slotted nozzle 380. 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 the adjacent panel assemblies 300.

[0080] Also refer to Figure 3 and Figure 5 and shows a left view of the 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 6 , for 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 be at the intermediate section 316 (see Figure 13) has a reduced width thereon such that the panel assemblies 300 are spaced apart on their adjacent intermediate sections 316 to define an air flow gap 216. Additionally and / or alternatively, the air flow gap 216 can be defined and maintained by supports or spacers 386 between the intermediate sections 316 of adjacent panel assemblies 300. The supports or spacers 386 extend outwardly in a lateral direction from the intermediate sections 316 near the longitudinal ends 308 and 310. The intermediate section 316 of each frame 302 can additionally and / or alternatively include snap fittings 372 and corresponding holes 374 near the longitudinal ends 308 and 310 (as Figure 6 and Figure 7 shown). The snap fittings 372 and corresponding holes 374 located on the intermediate section 316 of the frame 302 can facilitate connecting adjacent panel assemblies 300 at adjacent intermediate sections. In addition to the spacers 386, snap fittings 372 and corresponding holes 374 can also be included. Alternatively, in some examples, the spacer 386 can be a snap fitting 372 that engages the holes 374 of adjacent panel assemblies 300 to connect adjacent panel assemblies and maintain the width of the air flow gap 216.

[0081] The panel assemblies 300 are arranged in the tee 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 tee 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 tee 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 tee heat exchanger 200. The leading edge of the frame 302 positioned near the first longitudinal end 308 is near the air inlet 224. The trailing edge of the frame 302 near the second longitudinal end 310 is near the air outlet 226.

[0082] The ports 340, 342, 346, and 348 of the panel assembly 300 are aligned to define corresponding 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.

[0083] The panel assembly 300 may include O-rings or other elastomeric seal 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 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 adjacent panel assemblies 300. In some examples, the elastomeric seal 384 is a radial seal (e.g., a radial O-ring seal). Additionally, in 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.

[0084] As Figure 3 and Figure 5As shown, 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 via conduit 250. The liquid desiccant outlet 238 is fluidly connected to the liquid desiccant outlet manifold 244 via conduit 252. The heat transfer fluid inlet 232 is fluidly connected to the heat transfer fluid inlet manifold 246 via conduit 254. The heat transfer fluid outlet 234 is fluidly connected to the heat transfer fluid outlet manifold 248 via 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 the end of the conduit to an appropriate one of the ports 340, 342, 346, and 348 in the port panel assembly 300 (i.e., the panel 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 panel assembly 300 using any suitable means - including fasteners, threads, clamps, etc.

[0085] Conduits 250 and 256 extend between the end plate 218 and the port panel assembly 300 at the first lateral side 202. Conduits 252 and 254 extend between the end plate 220 and the port panel 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 the 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 the 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.

[0086] 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.

[0087] 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.

[0088] 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 Figure 1 ) enters via 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 circuit 108, and the heat transfer fluid 350 is from Figure 1 the regulator heat transfer fluid of the regulator subsystem 104 shown in

[0089] , 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 circuit 108, and the heat transfer fluid 350 is from Figures 3 to 5 the regenerator heat transfer fluid of the regenerator subsystem 106 shown in Figure 7 and Figure 8 , and the heat exchanger 200 is used to heat the moisture and discharge the moisture into the air flowing through the air gap 216. Figure 7 and Figure 8 The liquid desiccant 344 flows from the first side portion 202 into the liquid desiccant inlet manifold 242 via the liquid desiccant inlet 236 and the conduit 250 ( Figures 3 to 5 shown in Figure 7 ). 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 ( Figure 7 and Figure 8 ) on each of the plates 326 and 328, flows downward through the liquid desiccant channels 336 and 338, and via the orifices 362 ( Figure 7 and Figure 8as shown in ) enters the liquid desiccant manifold region 322. As the liquid desiccant 344 flows behind 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 membranes 332 and 334 or desorbs water into the air. Permitting moisture to permeate through each of membranes 332 and 334 enables moisture to transfer between the liquid desiccant 344 and the air in the air gap 216. Alternatively, membranes 332, 334 may not be included, and the liquid desiccant 344 flows over the outer surfaces of plates 326, 328 and directly contacts the air. The liquid desiccant 344 that has absorbed or desorbed moisture exits each panel assembly 300 via orifice 358 from the respective liquid desiccant manifold region 322 and flows toward the second lateral side 204 through the liquid desiccant outlet manifold 244. The liquid desiccant 344 exits the heat exchanger 200 via conduit 252 and liquid desiccant outlet 238 ( Figure 5 as shown in ).

[0090] 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 ). The heat transfer fluid 350 enters each panel assembly 300 via orifice 352 from the heat transfer fluid inlet manifold 246. 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 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 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 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 conduit 256 and heat transfer fluid outlet 234 ( Figures 3 to 5 as shown in ).

[0091] In the illustrated embodiment, the flow directions of the heat transfer fluid 350 and the liquid desiccant 344 are shown as examples only and may be varied in other embodiments of the heat exchanger 200. For example, the liquid desiccant 344 may flow upward through the desiccant channels 336 and 338 in the panel assembly 300. In these examples, the directions in which the liquid desiccant 344 flows 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 in which the heat transfer fluid 350 flows 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 in the same direction through the panel assembly.

[0092] The inlet air stream entering via the air flow inlet 224 is distributed into the air flow gap 216 and flows therethrough in the air flow direction 278 and exits via the air flow outlet 226. For example, in cases where membranes 332, 334 with a high porosity are used or where the membranes 332, 334 are not included and the air stream directly contacts the liquid desiccant flowing over the exposed outer surfaces of the plates 326, 328, liquid desiccant droplets may be entrained in the air stream. The entrained liquid desiccant may undesirably accumulate in components or equipment downstream of the heat exchanger 200 (e.g., accumulate in the air circulation duct system). Thus, in some cases, it may be desirable to remove or eliminate the entrained liquid desiccant from the air stream leaving the heat exchanger 200.

[0093] Figure 12 is a rear perspective view of the three-way heat exchanger 200, in which various components are omitted to show the internal components of the three-way heat exchanger 200 (similar to Figure 5 ) and Figure 12 shows a liquid desiccant mist eliminator 400 that may be included in the heat exchanger. The mist eliminator 400 is positioned at the air flow outlet 226 and facilitates the selective removal of entrained liquid desiccant (e.g., in the form of mist or droplets) from the air stream leaving the heat exchanger 200. The mist eliminator 400 is also removably connected to the heat exchanger 200 such that the mist eliminator 400 can be easily removed from and installed in the heat exchanger 200. In this way, the mist eliminator 400 can be selectively included in or omitted from the heat exchanger 200 depending on, for example, the operating conditions of the heat exchanger and / or the likelihood of liquid desiccant being entrained in the air stream.

[0094] The mist eliminator 400 includes a screen 402 made of a suitable material for selectively removing liquid desiccant from an air stream. For example, the screen 402 can be made of a hydrophobic material, such as a hydrophobic polymeric material. The hydrophobic material is suitably capable of interacting with the entrained liquid desiccant in the air stream, removing or extracting the entrained liquid desiccant from the air stream, and guiding the removed liquid desiccant to move vertically downward along the screen 402. The liquid desiccant reservoir 280 is positioned below the removed liquid desiccant flowing downward along the screen 402. The removed liquid desiccant can be reintroduced into the liquid desiccant loop (e.g., liquid desiccant loop 108) or can be disposed of subsequently. The hydrophobic material can be suitably compatible with the liquid desiccant to facilitate maintaining the durability of the service life of the screen 402, reducing the tendency of the liquid desiccant to corrode or otherwise degrade the screen, and / or enabling the liquid desiccant to be reused in operation. The compatibility of the hydrophobic material can depend on the type of liquid desiccant used. For example, in an example where lithium chloride is used as the liquid desiccant, the hydrophobic polymeric materials that can be used to manufacture the screen 402 and are compatible with the liquid desiccant include polyethylene and / or polypropylene and other materials. Other suitable hydrophobic materials that can be used in addition to and / or as an alternative to polyethylene and / or polypropylene include, for example, acrylic, polyester (e.g., polyethylene terephthalate (PET)), nylon, rayon, polyethersulfone, fluoropolymers (e.g., polytetrafluoroethylene), vinyl chloride (e.g., polyvinyl chloride (PVC) and / or chlorinated polyvinyl chloride (CPVC)), and combinations thereof. The screen 402 can be made of a thin material (e.g., having a thickness of less than about 5 mm) and can also be referred to as a mesh membrane.

[0095] The screen 402 can be configured to selectively remove entrained liquid desiccant without substantially affecting the flow of air leaving the heat exchanger 200. For example, the mesh size of the screen 402 can be selected such that the screen can selectively remove the entrained liquid desiccant from the air stream without substantially increasing the pressure drop of the air stream through the air inlet 224 and the air outlet 226 and / or without substantially creating a resistance to the air stream at the air outlet 226. The screen 402 can have a mesh size (or an opening of that size) between about 1 micrometer (μm) and about 1 millimeter (mm), such as between about 1 μm and about 500 μm, between about 50 μm and about 500 μm, between about 50 μm and about 250 μm, between about 50 μm and about 150 μm, or between about 100 μm and about 150 μm. The opening area of the screen 402 measured relative to the total area of the screen can be between about 20% and about 80%, between about 20% and about 60%, between about 25% and about 50%, or between about 35% and about 45%.

[0096] The wire mesh 402 is removably connected to the panel assembly 300 (the panel assembly 300 may also be referred to as a heat exchange structure) at the second longitudinal end 310 using two connectors 404, and the two connectors 404 are removably connected to and held by the mist eliminator retainer 388 of each panel in the panel assembly. This will be described in more detail with reference to Figure 13 and Figure 14A and Figure 14B the mist eliminator retainer 388. As Figure 15 and Figure 16 shown, each connector 404 is connected to an end 406 or 408 of the wire mesh 402. The first connector 404 is connected to the first end 406, and the second connector 404 is connected to the second end 408. The wire mesh 402 may have connection features (such as the holes 410 shown in Figure 15 and Figure 16 ) that enable the connectors 404 to be connected to the respective ends 406, 408.

[0097] In the exemplary mist eliminator 400, the connectors 404 are each flexible clamps 404 that are connected to the respective ends 406, 408 of the wire mesh 402 and are capable of connecting to the mist eliminator retainer 388 of the panel assembly 300. Each clamp 404 includes a first portion 412 and a second portion 414. The first portion 412 and the second portion 414 are hingedly joined by a hinge 416 that extends between the first portion 412 and the second portion 414. The hinge 416 allows the clamp 404 to fold between a closed position (shown in Figure 15 ) and an open position (shown in Figure 16 ).

[0098] Figures 17 to 19 The features of the clamp 404 are shown in more detail. The clamp 404 is shown in Figures 17 to 19Each of which is in an open position. The first part 412 includes a fitting 418 that projects from the first side 422 of the clamp 404. The fitting 418 is inserted into holes 410 at the corresponding ends 406, 408 of the screen 402. The number of fittings 418 included in the clamp 404 corresponds to the number of holes 410 defined at the corresponding ends 406, 408 of the screen 402. In the exemplary mist eliminator 400, there are seven fittings 418 on each clamp 404 and seven corresponding holes 410 at each end 406, 408 of the screen 402. In other examples, more or fewer fittings 418 and holes 410 may be included. The second part 414 includes openings 420 corresponding to the fittings 418. Each opening 420 extends between the first side 422 and the second side 424 of the clamp 404. The openings 420 are sized, shaped, and positioned to receive the fittings 418 of the first part 412 when the clamp 404 is moved from the open position to the closed position. The number of openings 420 included in the clamp 404 corresponds to the number of fittings 418 of the clamp 404 and the number of holes 410 defined at the corresponding ends 406, 408 of the screen 402. Thus, there are seven openings 420 on each clamp 404, and more or fewer openings 420 may be included depending on the number of fittings 418 and holes 410.

[0099] The clamp 404 is capable of being bent or folded about a hinge 416 formed as a weakened area of the clamp 404 that extends between the first part 412 and the second part 414. In Figure 17 and Figure 18In the orientation shown, the clamp 404 can be bent or folded about the hinge 416 in a counterclockwise direction such that the first sides 422 of the first portion 412 and the second portion 414 face each other and the fitting 418 is received by the opening 420. The fitting 418 includes a flared region 426 that seats against a groove 428 within the corresponding opening 420 when the clamp 404 is in the closed position to effect a snap fit between the fitting 418 and the opening 420. The snap fit between each fitting 418 and the opening 420 holds the clamp 404 in the closed position without prematurely moving to the open position. The second side 424 of the clamp 404 forms an outwardly directed surface of the first portion 412 and the second portion 414 when the clamp is in the closed position. A protrusion 430 projects from the second side 424 of the second portion 414 of the clamp 404. The protrusion 430 facilitates holding the clamp 404 within the mist eliminator retainer 388 of the panel assembly 300 described below. In the exemplary clamp 404, there is one protrusion 430 projecting adjacent each opening 420 such that the clamp 404 includes seven discrete protrusions 430. More or fewer protrusions 430 may be included depending on the number of openings 420. In some examples, an integral protrusion 430 may extend adjacent each of the openings 420 through the second side 424 of the second portion 414 of the clamp 404.

[0100] Referring Figure 13 and Figure 14A and Figure 14B , the frame 302 of each panel assembly 300 (also referred to as a heat exchange structure) includes two mist eliminator retainers 388 for removably connecting the mist eliminator 400 to the panel assembly 300. The first mist eliminator retainer 388 is positioned adjacent the first corner flange 364 of the frame 302 at the first vertical end 304 and the second longitudinal end 310. The second mist eliminator retainer 388 is positioned adjacent the third corner flange 368 of the frame 302 at the second vertical end 306 and the second longitudinal end 310. The first mist eliminator retainer 388 of the panel assembly 300 is configured to connect to and hold the first coupler 404 (e.g., the first clamp 404) of the mist eliminator 400, and the second mist eliminator retainer 388 of the panel assembly 300 is configured to connect to and hold the second coupler 404 (e.g., the second clamp 404) of the mist eliminator 400.

[0101] Each mist eliminator retainer 388 includes a finger 390 that defines a slot 392 between the finger 390 and the corresponding corner flange 364 or 368. The slot 392 is sized and shaped to receive and hold the coupler 404 of the mist eliminator 400. In Figure 13 andFigure 14A and Figure 14B In the example shown in, slot 392 is sized and shaped to receive and hold fixture 404. The following description of slot 392 relates to an example configuration of a slot for use in receiving, connecting to, and holding fixture 404 described above with reference to Figures 15 to 19 In other examples, the configuration of slot 392 may vary according to the configuration of coupler 404. For example, Figure 24 depicts another example mist eliminator (designated 500), where the coupler (designated 504) is a rod or post inserted into rod slide fittings 510 at opposite ends 506, 508 of a screen (designated 502). In an example of using mist eliminator 500, slot 392 may be configured to receive and hold rod 504 to removably connect mist eliminator 500 to panel assembly 300.

[0102] Each slot 392 includes a tooth portion 394 projecting inwardly from finger portion 390 and a guide portion 396 projecting outwardly from corner flange 364 or 368. Tooth portion 394 and guide portion 396 are located in a first cavity 398a of slot 392. Each slot 392 narrows from first cavity 398a to second cavity 398b. First cavity 398a and second cavity 398b conform slot 392 to the shape of fixture 404 when in the closed position such that fixture 404 can be positioned in slot 392 (see Figure 22 and Figure 23 , which depicts fixture 404 positioned in slot 392). Tooth portion 394 of slot 392 engages a protrusion 430 of fixture 404 to hold fixture 404 in slot 392. Guide portion 396 may cause slot 392 to be shaped to conform to the shape of fixture 404 and / or otherwise facilitate more easily guiding fixture 404 into slot 392.

[0103] Figures 20 to 23 is a photograph depicting the assembly of mist eliminator 400 in heat exchanger 200. Figure 20 and Figure 21 depict the sequence of connecting fixture 404 to one of ends 406, 408 of screen 402. Figure 22 and Figure 23 each depict fixture 404 inserted into slot 392 of panel assembly 300 (or heat exchange structure) for removably connecting mist eliminator 400 to heat exchanger 200. As Figure 20As shown, the fitting 418 of the clamp 404 in the open position is inserted into the corresponding holes 410 at the respective ends 406, 408 of the wire mesh 402. Then the clamp 404 is closed by folding the second part 414 about the hinge 416 towards the first part 412 such that the first side portions 422 of the first part 412 and the second part 414 face each other and the fitting 418 is received by and snap-fitted into the corresponding openings 420. Figure 21 The clamp 404 in the closed position is shown, wherein the respective ends 406, 408 of the wire mesh 402 are clamped between the first part 412 and the second part 414 and held by the snap-fit between the fitting 418 and the opening 420. Figure 21 Also shown is a protrusion 430 protruding from the second (outer) side portion 424 on the second part 414 of the clamp 404.

[0104] In the case where two clamps 404 are connected to the wire mesh 402, with each clamp 404 located at one end 406, 408 of the wire mesh, the mist eliminator 400 is connected to the panel assembly 300 by inserting each clamp 404 through the slot 392 of the panel assembly. In particular, one of the clamps 404 is inserted through the slot 392 ([ Figure 22 ) located adjacent to the first corner flange 364 of the panel assembly 300, and the other clamp of the clamps is inserted through the slot 392 ([ Figure 23 ) located adjacent to the third corner flange 368 of the panel assembly. The clamp 404 can be continuously inserted through the slot 392 in the lateral direction. The slot 392 conforms to the shape of the clamp 404 in the closed position so that the clamp can be easily guided through the slot. The teeth 394 in the slot 392 engage the protrusion 430 of the clamp 404 to hold the clamp in the slot (e.g., by restricting the vertical movement of the clamp 404 in the slot 392). In the case where the clamp 404 is connected to the wire mesh 402 and inserted in the slot 392, the wire mesh is positioned at the air flow outlet 226 (e.g., adjacent to or near the air flow outlet 226) (as shown in Figure 12 ) for selectively removing entrained liquid desiccant from the air flow. The clamp 404 can be easily removed from the slot 392 in the lateral direction to remove the mist eliminator 400 from the heat exchanger 200.

[0105] Figure 25An example method 600 of operating a heat exchanger, such as a three-way heat exchanger 200, is provided. Method 600 includes directing 602 air through the heat exchanger, where the air flows through an air inlet 224 of the heat exchanger, an air flow gap 216 defined between adjacent heat exchange structures (such as adjacent panel assemblies 300) of the heat exchanger, and an air outlet 226 of the heat exchanger along an air flow direction 278. Method 600 further includes directing 604 a liquid desiccant to each of the heat exchange structures in the heat exchanger (such as each of the panel assemblies in panel assembly 300). The liquid desiccant flows across the surface of each heat exchange structure (such as the outer surfaces of plates 326, 328). Method 600 may include conditioning the air by transferring moisture between the air and the liquid desiccant, using the liquid desiccant flowing across the surface of each heat exchange structure. Moisture may be transferred between the air and the liquid desiccant by direct contact between the air and the liquid desiccant (such as where the liquid desiccant flows across the exposed outer surfaces of plates 326, 328 and does not include membranes 332, 334). Alternatively, moisture transferred between the air and the liquid desiccant may permeate through a membrane (such as membranes 332, 334) positioned on the surface (such as the outer surfaces of plates 326, 328) of each heat exchange structure (such as each panel assembly 300). Method 600 further includes selectively removing 606 entrained liquid desiccant from the air using a screen 402 positioned at the air outlet 226 (such as adjacent to or near the air outlet 226). The liquid desiccant removed 606 from the air may be collected in a liquid desiccant reservoir 280 positioned below the screen 402.

[0106] The example systems and methods described include a three-way heat exchanger capable of operating to remove heat and moisture from an air stream and / or discharge heat and moisture into an air stream. The three-way heat exchanger may include heat exchange structures and an air flow gap through which a heat transfer fluid and a liquid desiccant are directed, and the air flow gap is defined between adjacent heat exchange structures for directing air therethrough along an air flow direction. The example three-way heat exchanger includes a liquid desiccant mist eliminator positioned at the air outlet, which intersects the air flow direction and facilitates selectively removing entrained liquid desiccant from the air flowing through the heat exchanger. The liquid desiccant mist eliminator may be selectively and easily installed and removed from the heat exchanger. The liquid desiccant mist eliminator may include a screen made of a suitable material, such as a hydrophobic polymeric material, that is compatible with the liquid desiccant and is also capable of extracting the liquid desiccant from the air. The screen may also be sized and configured to facilitate reducing any negative impact the screen may have on the efficient and / or effective operation of the heat exchanger, such as by minimizing or eliminating any increase in pressure drop or air resistance caused by the screen.

[0107] Embodiments of the HVAC system and the method of the operating system have been described in detail above. The system and method are not limited to the specific embodiments described herein. Instead, the components of the system and method can be used independently and separately from other components described herein. For example, the system and method described herein can be used in systems other than the HVAC system.

[0108] When introducing elements of the present disclosure or embodiments of the present disclosure, 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 additional elements may exist in addition to the recited elements. The use of terms indicating a particular orientation (e.g., "top", "bottom", "side", "vertical", "lateral", "longitudinal", etc.) is for convenience of description and does not require any particular orientation of the item being described.

[0109] 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, are intended to cover 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.

[0110] Since various changes can be made to the above-described construction and method 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 restrictive.

Claims

1. A heat exchanger operable to condition air using a liquid desiccant, the heat exchanger comprising: an air flow inlet and an air flow outlet; heat exchange structures positioned between the airflow inlet and the airflow outlet, each heat exchange structure having a surface for flow of the liquid desiccant; as well as A mesh screen is positioned at the air flow outlet to selectively remove entrained liquid desiccant from the air.

2. The heat exchanger according to claim 1, wherein: The mesh is made of a hydrophobic polymer material.

3. The heat exchanger according to claim 2, wherein: The hydrophobic polymer material is compatible with the liquid desiccant.

4. The heat exchanger according to claim 1, wherein: The mesh is made of a hydrophobic material selected from the group consisting of polyethylene, polypropylene, acrylic, polyester, nylon, rayon, polyethersulfone, fluorocarbon polymers, vinyl chloride, and combinations thereof.

5. The heat exchanger of claim 2, further comprising a liquid desiccant collection reservoir positioned below the screen.

6. The heat exchanger according to claim 2, wherein: The screen has openings with a size between 1 micron and 1 millimeter.

7. The heat exchanger according to claim 2, wherein: The mesh has an open area between 20% and 80%.

8. The heat exchanger according to claim 1, wherein: The surface of each structure for flow of the liquid desiccant is an exposed outer surface for direct contact between the liquid desiccant and the air.

9. The heat exchanger according to claim 1, wherein: The structures each include a membrane positioned on the surface, wherein a desiccant channel is defined between the membrane and the surface for flow of the liquid desiccant.

10. A heat exchanger operable to condition air using a liquid desiccant, the heat exchanger comprising: an air flow inlet and an air flow outlet; heat exchange structures positioned between the airflow inlet and the airflow outlet, each heat exchange structure having a surface for flow of the liquid desiccant; as well as A mesh screen is positioned at the airflow outlet and is removably connected to the heat exchange structure.

11. The heat exchanger according to claim 10, wherein: The screen is removably connected to the heat exchange structure using two couplers, wherein each coupler is connected to an end of the screen and inserted into a slot defined by the heat exchange structure.

12. The heat exchanger according to claim 11, wherein: Each coupler is a flexible clamp connected to a respective end of the screen, the clamp comprising a first portion hingedly engaged to a second portion, the first portion comprising a fitting inserted into a hole defined at the end of the screen, and the second portion comprising an opening sized to receive the fitting when the clamp is in a closed position.

13. The heat exchanger according to claim 12, wherein: The clamp is retained in the slot defined by the heat exchange structure by teeth in the slot engaging the clamp.

14. The heat exchanger according to claim 10, wherein: The mesh is made of a hydrophobic polymer material.

15. The heat exchanger of claim 10, further comprising a liquid desiccant collection reservoir positioned below the screen.

16. The heat exchanger according to claim 10, wherein: The surface of each structure for flow of the liquid desiccant is an exposed outer surface for direct contact between the liquid desiccant and the air.

17. The heat exchanger according to claim 10, wherein: The structures each include a membrane positioned on the surface, wherein a desiccant channel is defined between the membrane and the surface for flow of the liquid desiccant.

18. A method of operating a heat exchanger, the method comprising: directing air through the heat exchanger, wherein the air flows in an airflow direction through an airflow inlet of the heat exchanger, airflow gaps defined between adjacent heat exchange structures of the heat exchanger, and an airflow outlet of the heat exchanger; directing a liquid desiccant to each of the heat exchange structures, wherein the liquid desiccant flows across a surface of each heat exchange structure; and Entrained liquid desiccant is selectively removed from the air using a mesh screen positioned at the air flow outlet.

19. The method of claim 18, further comprising collecting the removed liquid desiccant in a liquid desiccant reservoir positioned below the screen.

20. The method of claim 18, further comprising conditioning the air using the liquid desiccant flowing across a surface of each heat exchange structure, wherein Moisture is transferred between the air and the liquid desiccant by one of: i) direct contact between the air and the liquid desiccant; and ii) permeating moisture through a membrane positioned on a surface of each heat exchange structure.

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