Patent Publication Number: US-2022235944-A1

Title: Heat pump systems

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to heat pump systems and, in particular, to air flow paths for heat pump systems. 
     BACKGROUND 
     Decreasing the energy consumption of water heaters can have a large impact on the energy usage of an overall household or other building. Some studies have found the water heater to be the second-most energy consuming appliance in a typical household, trailing only the heating and air conditioning system in the home. Particularly in heat pump water heater systems, increasing the heat transfer coefficient of the heat exchangers is desirable because increased efficiency of the heat pump will lead to increased efficiency of the overall water heater. When ambient air enters the heat pump to exchange heat with a thermal working fluid, a large portion of the heat transfer efficiency can be lost due to maldistribution of air (e.g., uneven distribution of air across the heat exchanger). Air recirculation and general turbulent flow can reduce the contact area of the heat exchanger that is available for heat transfer, thus reducing the heat transfer coefficient and efficiency of the system. 
     What is needed, therefore, are heat pump units that improve the quality and the volume of a flow of ambient air entering the heat pump to improve the heat transfer coefficient of the heat pump. The present disclosure addresses this need as well as other needs that will become apparent upon reading the description below in conjunction with the drawings. 
     BRIEF SUMMARY 
     The present disclosure relates generally to heat pump systems and, in particular, to air flow paths for heat pump systems. 
     The disclosed technology can include a heat pump system for a water heater. The heat pump system can comprise a housing defining an interior chamber, an air inlet, an air outlet, and an evaporator unit within the interior chamber. Air entering the interior chamber can transfer heat to the evaporator unit before flowing out of the air outlet. The air inlet can be included in a top pan which defines a top side of the interior chamber. The top pan can be configured to engage a top end of the heat pump system. The air outlet can be positioned on a side of the heat pump system. The air outlet can be configured such that an air flow path extends between the air inlet and the air outlet. The evaporator unit can be positioned in the air flow path, thereby creating a cross flow across the evaporator unit. The air flow path can be reversible, such that the air inlet is positioned on a side of the heat pump system and the air outlet is positioned on a top side of the interior chamber. 
     The heat pump system can also include a flue pipe positioned in the air flow path. The flue pipe cross-section can have a leading edge, a trailing edge, and a central portion between the leading edge and the trailing edge. A width of the leading edge can be less than or equal to a width of the central portion. The flue pipe can have an elliptical cross-section, wherein a major axis of the elliptical cross-section is parallel to the air flow path. The interior chamber can also be partitioned into a first interior chamber and a second interior chamber being fluidly separated, and the flue pipe can be positioned in the second interior chamber separate from the air flow path in the first interior chamber. 
     The heat pump system can also comprise side baffles positioned between the evaporator unit and the housing. Each of the side baffles can be disposed at an angle such that the side baffles direct the air flow path to the evaporator unit. Alternatively, or additionally, the air inlet can be a first air inlet and the housing can further comprise a second air inlet in fluid communication with the air flow path. The second air inlet can be positioned proximate to one of the side baffles to encourage air flow from the second air inlet to the air flow path. 
     The heat pump system can further include a curved elbow attached to the air inlet to direct the air flowing therethrough to the evaporator unit. 
     The disclosed technology can also include heat pump systems comprising a housing. The housing can have an internal volume and a partition defining a first interior chamber and a second interior chamber within the internal volume. The first interior chamber and the second interior chamber can be fluidly separated. The first interior chamber can also have an air inlet, and air outlet, and an air flow path extending therebetween. The heat pump system can also include an evaporator unit positioned at least partially in the air flow path in the first interior chamber. The evaporator unit can be curved thereby increasing a surface area of the evaporator unit exposed to the air flow path. The evaporator unit can be concave relative to the air flow path. 
     The disclosed heat pump systems can also comprise a condenser unit, a compressor, and a thermal expansion valve, all of which can form a fluid circuit. The fluid circuit can flow a heat transfer fluid therethrough. 
     These and other aspects of the present disclosure are described in the Detailed Description below and the accompanying figures. Other aspects and features of examples of the present disclosure will become apparent to those of ordinary skill in the art upon reviewing the following description of specific examples of the present disclosure in concert with the figures. While features of the present disclosure may be discussed relative to certain examples and figures, all examples of the present disclosure can include one or more of the features discussed herein. Further, while one or more examples may be discussed as having certain advantageous features, one or more of such features may also be used with the various examples of the disclosure discussed herein. In similar fashion, while examples may be discussed below as device, system, or method examples, it is to be understood that such examples can be implemented in various devices, systems, and methods of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate multiple examples of the presently disclosed subject matter and serve to explain the principles of the presently disclosed subject matter. The drawings are not intended to limit the scope of the presently disclosed subject matter in any manner. 
         FIG. 1  illustrates a side cross-sectional view of a heat pump system in accordance with the present disclosure. 
         FIG. 2A  illustrates a side cross-sectional view of a heat pump system in accordance with the present disclosure. 
         FIG. 2B  illustrates a top-down cross-sectional view of the heat pump system of  FIG. 2A  in accordance with the present disclosure. 
         FIG. 2C  illustrates additional top-down cross-sectional views of the flue pipe of  FIG. 2B  in accordance with the present disclosure. 
         FIG. 3A  illustrates a top-down cross-sectional view of a heat pump system in accordance with the present disclosure. 
         FIG. 3B  illustrates a side cross-sectional view of heat pump system in accordance with the present disclosure. 
         FIG. 4A  illustrates a top-down cross-sectional view of a heat pump system in accordance with the present disclosure. 
         FIG. 4B  illustrates an isometric and cross-sectional view of a heat pump system in accordance with the present disclosure. 
         FIG. 5  illustrates the air flow distribution for different air flow paths in a heat pump system in accordance with the present disclosure. 
         FIG. 6  illustrates a system diagram of a heat pump system in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     As described above, a problem with current water heaters is that ambient air flowing through heat pump systems, such as in the evaporator unit, is not evenly distributed across the heat exchanger. The fluid dynamics of current air flow paths tend to cause turbulent and/or obstructed flow, air recirculation, vortices, and other disruptive flow patterns. As a result, the amount of air contacting the heat pump working fluid is typically uneven, ineffective, or both. This can reduce the heat transfer coefficient of the heat exchanger and the overall efficiency of the heat pump, causing the system to waste additional time and energy to provide the necessary heat transfer. 
     Disclosed herein are heat pump systems comprising a housing defining an interior chamber, an air flow path extending through the interior chamber from an air inlet to an air outlet, and a heat exchanger (e.g., an evaporator unit) positioned in the air flow path. The heat exchanger can interact with the air flowing through the air flow path and across the heat exchanger to conduct a heat exchange between the air and a thermal working fluid flowing through an internal portion of the heat exchanger. If a flue pipe is also positioned in the air flow path, the flue pipe can have a shape (e.g., elliptical shape) to improve the aerodynamic flow around the flue pipe (e.g., a foil). The heat pump system can include side baffles to angle and direct air flow toward the heat exchanger, and/or the air inlet can include or be located proximate a curved elbow for similar reasons. Alternatively or in addition, the interior chamber can include one or more secondary air inlets leading into the air flow path to increase the air flow rate through the heat pump systems. These secondary air inlets can be located on or near the side baffles. Optionally, the air flow path can be partitioned away from other components of the heat pump system (e.g., the flue pipe) so that there are no obstructions in the air flow path (or a limited or reduced number thereof). The air inlet can be positioned on a top of the interior chamber, and the air outlet can be positioned on a side of the interior chamber, or vice versa. 
     While the present disclosure is described relating to heat pump systems for water heaters and evaporators for heat pump systems, it is understood that the technology described herein is not so limited. Indeed, unless otherwise explicitly stated, the present disclosure can be used in conjunction with any heat transfer unit configured to transfer latent heat (e.g., an evaporator or a condenser), sensible heat (a heat exchanger, a heater, or a chiller), or both from air to another working fluid. Additionally, unless otherwise explicitly stated, the present disclosure is not limited to use in water heating applications and can be used in heat pumps for any application. 
     Although certain examples of the disclosure are explained in detail, it is to be understood that other examples and applications are contemplated. Accordingly, it is not intended that the disclosure is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. Other examples of the disclosure are capable of being practiced or carried out in various ways. Also, in describing the disclosed technology, specific terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
     Herein, the use of terms such as “having,” “has,” “including,” or “includes” are open-ended and are intended to have the same meaning as terms such as “comprising” or “comprises” and not preclude the presence of other structure, material, or acts. Similarly, though the use of terms such as “can” or “may” are intended to be open-ended and to reflect that structure, material, or acts are not necessary, the failure to use such terms is not intended to reflect that structure, material, or acts are essential. To the extent that structure, material, or acts are presently considered to be essential, they are identified as such. 
     By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named. 
     It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. 
     The components described hereinafter as making up various elements of the disclosure are intended to be illustrative and not restrictive. Many suitable components that would perform the same or similar functions as the components described herein are intended to be embraced within the scope of the disclosure. Such other components not described herein can include, but are not limited to, for example, similar components that are developed after development of the presently disclosed subject matter. 
     Reference will now be made in detail to examples of the disclosed technology, some of which are illustrated in the accompanying drawings. Wherever convenient, the same references numbers will be used throughout the drawings to refer to the same or like parts. 
       FIG. 1  illustrates a cross-sectional component diagram of a heat pump system  100  for a water heater. As shown, the heat pump system  100  can comprise a housing  110 . The housing  110  can include a top pan of a water heater. The housing  110  can be of various sizes and can define an interior chamber  120  inside of which certain components of the heat pump system  100  (or the water heater) can be housed. One such component housed within the interior chamber  120  can include an evaporator unit  130 . The evaporator unit  130  can be a heat exchanger configured to conduct a heat exchange between air in the interior chamber  120  and a working fluid flowing through the evaporator unit  130 . The heat exchanged by the evaporator unit  130  can be latent heat (e.g., heat to change the phase of working fluid from liquid to vapor), sensible heat (e.g., heat to change the temperature of the working fluid), or a combination thereof. 
     The heat pump system  100  can have an air inlet  140  which can be an aperture in the housing  110  allowing air to flow from the external environment into the interior chamber  120 . The evaporator assembly  100  can also include an air outlet  150 , which can be another aperture in the housing  110  allowing air to flow out of the interior chamber  120 . The air outlet  150  can guide egress of the air back to the external environment or into another chamber, another component of the water heater, or some other location. 
     The air inlet  140  can be positioned on a top side of the heat pump system  100 , as shown. Such a top side can be referred to as a “top pan” that engages the heat pump system  100 . The top pan can also define the top side of the interior chamber  120  (or a portion thereof) if the top side is not already defined by the housing  110 . The air outlet  150  can be positioned on a side of the heat pump system  100 , as shown. Alternatively, the air inlet  140  can be positioned on a side of the heat pump system  100 , and the air outlet can be positioned on a top side of the heat pump system; in such a manner, the air flow from the air inlet  140  to the air outlet  150  can be reversed. 
     The air inlet  140  and the air outlet  150  can form an air flow path  160  extending therebetween along which air entering the heat pump system  100  flows from the air inlet  140  to the air outlet  150 . The evaporator unit  130  can be positioned within the air flow path  160  to ensure that flowing air contacts the evaporator unit  130  to transfer heat. Increasing the average velocity along the air flow path  160 , and therefore across the heat exchanger, can increase the Reynolds number of the air in contact with the evaporator unit  130 . Without wishing to be bound by any particular scientific theory, increasing the Reynolds number of the air in contact with the evaporator unit  130  can increase the heat transfer coefficient of the evaporator unit  130 . 
     Alternatively, if the air along the air flow path  160  is disrupted or uneven, the Reynolds number will decrease, thus decreasing the heat transfer coefficient of the evaporator unit  130 . While uneven flow may result in higher local air velocities in certain locations along the evaporator unit  130 , due to turbulence and air recirculation, others locations along the evaporator unit  130  can receive very little air flow and/or air flow having a low local air velocity, resulting in the total average air velocity along the evaporator unit  130  being lower than the higher local air velocities. Thus, there is an opportunity for improvement in the heat transferability of evaporator units in heat pumps. It is desirable to improve the air velocity distribution to thereby increase the Reynolds number of the air contacting the evaporator unit, as shown in Equation 1: 
     
       
         
           
             
               
                 
                   
                     R 
                     ⁢ 
                     e 
                   
                   = 
                   
                     
                       
                         ρ 
                         ⁢ 
                         u 
                         ⁢ 
                         L 
                       
                       μ 
                     
                     = 
                     
                       
                         u 
                         ⁢ 
                         L 
                       
                       
                         v 
                         ⁢ 
                         
                             
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
     where Re is the Reynolds number, ρ is the fluid density, u is the fluid flow speed, L is the characteristic length, μ is the dynamic viscosity of the fluid, and v is the kinematic viscosity of the fluid. 
     Consequently, because the average heat transfer coefficient also has a proportional relationship with the rate of heat transfer ({dot over (Q)}) as shown in Equation 2, it follows that increasing the Reynolds number of the air flow path  160  can also increase the rate of heat transfer of the evaporator unit  130 . 
       ( {dot over (Q)} )= hAΔT   (2)
 
     As shown, {dot over (Q)} represents the heat transfer rate, h represents the average heat transfer coefficient, and ΔT represents the temperature difference of the air between the air inlet  140  and the air outlet  150 . Additionally, as illustrated by Equation 4, the rate of heat transfer of the evaporator unit  130  can also be increased by increasing the heat transfer area (A). The heat transfer area can decrease if the air flow path  160  comprises flow disruptions, such as recirculation or vortices. 
       FIG. 2A  illustrates another cross-sectional component diagram of the heat pump system  100 . As shown, the heat pump system  100  can further comprise a flue pipe  210  positioned in the air flow path  160 . The flue pipe  210  can transport spent combustion gases from a gas-type water heater to a vent or other components of a water heater. As would be appreciated, the presence of the flue pipe  210  in the air flow path can cause a major air obstruction and disruption to air en route to the evaporator unit  130 . Additionally, the flue pipe  210  can be simply positioned within the housing  110 , rather than specifically in the air flow path  160 . The flue pipe  210  can be in any position as desired to transport the spent combustion gases out of the water heater. For example, the flue pipe  210  can extend from a bottom side of the housing  110  to a top side (e.g., a top pan) of the housing  110 . In such an example, the flue pipe  210  can extend through the interior chamber  120 , the air flow path  160 , both, or neither. 
     As shown in the top-down view of  FIG. 2B , however, the flue pipe  210  cross-section can have a leading edge, a trailing edge, and a central portion between the leading edge and the trailing edge. The flue pipe  210  cross-section can be or include a housing placed around the flue pipe  210 , or the flue pipe  210  cross-section can be integral to (or defined by) the flue pipe  210  itself. Various examples of a flue pipe  210  cross-section having a leading edge  212 , a trailing edge  214 , and a central portion  216  are illustrated in greater detail in  FIG. 2C . While certain examples are shown in  FIG. 2C  as having a flue pipe  210  located within a housing having a given flue pipe  210  cross-section, it is contemplated that the flue pipe  210  itself can have such a cross-sectional shape. A width of the leading edge can be less than or equal to a width of the central portion. For example, the flue pipe  210  can have an elliptical cross-section. Therefore, the major axis of the ellipse (e.g., the long side) can be oriented to be parallel to the air flow path  160 . In such a manner, the flue pipe  210  can have a cross-sectional shape having increased aerodynamics, which can increase the smoothness and the velocity of the air flowing around the flue pipe  210  to the evaporator unit  130 . As would be appreciated, and as described above, increasing the air flow and/or smoothness to the evaporator unit  130  can increase the Reynolds number and therefore the heat transfer coefficient of the evaporator unit  130 . In the example of an ellipse, such a shape can position the major axis of the flue pipe  210  to be parallel to the air flow path  160 , as generally illustrated in  FIG. 2B , for example. 
     The flue pipe  210  can have other shapes, such as shapes that have a leading edge with a width that is less than a width of the central portion. Furthermore, such shapes can have a leading edge with a width that is equal to a width of the central portion. Alternatively or in addition, at least a portion of the flue pipe  210  can have a shape in which the length of that portion of the flue pipe (i.e., generally perpendicular to a central axis of the flue pipe and/or generally parallel to the air flow path) is greater than the width. Alternatively, or additionally, for at least a portion of the flue pipe, the length of the flue pipe cross section “L” can be greater than the width of the flue pipe “W” as shown in  FIG. 2C . For instance, the flue pipe can be an oval, a geometric lens, a Vesica piscis lens, an asymmetrical lens, a triangle, a generally rounded triangle, an ellipse, a circle, a rounded quadrilateral, and the like. 
     As shown in  FIG. 3A , the heat pump system  100  can further comprise side baffles  310  angled toward the evaporator unit  130 . The side baffles  310  can be positioned in the interior chamber  120  between the evaporator unit  130  and the housing  110  to cut off potential bypass routes to force the air to interact with the evaporator unit  130 . Therefore, the side baffles  310  can increase the effective air flow rate in the air flow path  160  and the heat transfer coefficient of the evaporator unit  130 . Although two side baffles  310  are illustrated in  FIG. 3A , it is understood that any number of side baffles  310  can be positioned along the air flow path  160  to direct the air toward the evaporator unit  130 . 
     The side baffles  310  are depicted as being located at either (or both) of the lateral ends of the evaporator unit  130 . For example, as shown, each of the side baffles  310  can be angled from an outer wall of the interior chamber  120  toward an edge of the evaporator unit  130  to help direct air flow toward the evaporator unit and eliminate dead and/or recirculation areas adjacent to the evaporator unit  130 . However, it is understood that the side baffles  310  can be similarly positioned above and/or below the evaporator unit  130  and angled upward and/or downward from a top or bottom of the interior chamber  120  to further direct air flow toward the evaporator unit  130 . Indeed, the side baffles  310  can be positioned at any desirable angle to direct air flow into the evaporator unit  130 . 
     Additionally, even though the side baffles  310  are depicted as rectangular, it should be understood that the side baffles  310  can take on any suitable shape to improve air flow into the evaporator unit  130 . Indeed, the side baffles  310  can include fins, ridges, scallops, and other similar contouring to encourage smooth air flow over the side baffles  310 . Additionally, the side baffles  310  themselves can be curved, angled, triangular, scooped, and other geometries to encourage air flow toward the evaporator unit  130 . 
     Furthermore, the heat pump system  100  can include a secondary air inlet  320  in addition to the air inlet  140 . The secondary air inlet  320  can include one or more apertures in the housing  110  in any position suitable to feed additional air into the air flow path  160 . The secondary air inlet  320  can be positioned along the air flow path  160  (e.g., on a sidewall of the housing  110  at a position along the air flow path  160 ), or the secondary air inlet  320  can be positioned along the side baffles  310 . As would be appreciated, if the secondary air inlet  320  was not along the air flow path  160 , the side baffles  310  can help encourage air flow from the secondary air inlet  320  into either the air flow path  160  or the evaporator unit  130 . 
     While the secondary air inlet  320  is shown as being rectangular in cross-sectional shape in  FIG. 3B , it is understood that the secondary air inlet  320  can be any shape. Similarly, while the air inlet  140  is depicted as being semicircular, it is understood that the air inlet  140  can be any shape. For instance, the secondary air inlet  320  and the air inlet  140  can be trapezoidal, pentagonal, triangular, or have any number of sides that need not be equidistant. Furthermore, the air inlet  140  and the secondary air inlet  320  can also be modified as desired to alter and/or finely tune air flow, such as with the inclusion of a variety of scallops, fins, waves, and the like. While  FIG. 3A  depicts a single secondary air inlet  320 , it is contemplated that the heat pump system  100  can include two, three, four, or more secondary air inlets  320 . The various secondary air inlets  320  can be located in any pattern or configuration, whether it be in a symmetrical configuration (e.g., two secondary air inlets  320  located on opposite sides of the heat pump system  100 ) or an asymmetrical configuration. 
     Alternatively, or additionally, the air inlet  140  can have a curved elbow  330 , as shown in  FIG. 3B . While the curved elbow  330  is illustrated as having an approximately 90-degree bend, the curved elbow  330  can direct incoming air in any desired direction. For example, the curbed elbow  330  can have a bend angle in a range between approximately 5 degrees and approximately 90 degrees. Thus, the curved elbow  330  can direct the air flow in any desired direction. For instance, it may be aerodynamically advantageous for the curved elbow  330  to direct air in an at least partially lateral direction (e.g., toward the side baffles  310 ). 
     As shown in  FIG. 4A , the housing  110  can include a partition  410 . The partition  410  can divide the interior chamber  120  such that the housing  110  defines an interior chamber  120  (e.g., a first interior chamber) and a second interior chamber  420 . The first interior chamber  120  and the second interior chamber  420  can be fluidly and/or thermally separated from one another. The first interior chamber  120  can operate largely the same as described above. The first interior chamber  120  can include the air inlet  140 , the air outlet  150 , the air flow path  160 , and the evaporator unit  130  positioned between the air inlet  140  and the air outlet  150  along the air flow path  160 . The second interior chamber  420 , on the other hand, can house other components of the heat pump system  100 , such as the flue pipe  210 , and various valves, pipes, compressor, and/or pumps. In such a manner, the components of the heat pump system  100  in the second interior chamber  420  can be separated from the air flow path  160  such that the air flow path is substantially or completely unobstructed. 
     The partition  410  can cause the interior chamber  120  and the second interior chamber  420  to be divided into a variety of shapes. For example, the partition  410  can divide the housing into two semicircles. Alternatively, the partition  420  can be curved in a U-shape such that the air flow path  160  in the first interior chamber  120  can bend around the second interior chamber  420 , as shown in  FIG. 4B . The partition  410  can also be a series of angled segments rather than a continuous curve. For example, the partition  410  can comprise a first segment, a second segment, and a third segment extending in a first direction, a second direction, and a third direction, respectively, such that the first, second, and third segments form a continuous air flow path  160  between the air inlet  140  and the air outlet  150 . 
     In  FIGS. 4A and 4B , or in any of the previously described figures, the evaporator unit  130  is illustrated and described as being rectangular and perpendicular to the air flow path  160 . However, other positions, orientations, and geometries of the evaporator unit  130  are contemplated to be within the scope of the present disclosure. For example, the evaporator unit  130  can be positioned to be parallel to the air flow path  160  to increase the contact time with the flowing air. Alternatively, or additionally, the evaporator unit  130  can have a convex or a concave shape perpendicular to the air flow path  160  to increase the surface area of the evaporator unit  130 . 
     Furthermore, as described in reference to  FIG. 1 , the air inlet  140  and the air outlet  150  can be switched such that the air flow path  160  is reversed. A comparison between the “forward” air flow from  FIG. 1  to the “reversed” air flow is shown in  FIG. 5 . As shown in  FIG. 5 , the air operating under a reversed air flow path  160  (e.g., the air inlet  140  is positioned on a side of the heat pump system  100 , and the air outlet is positioned on a top side of the heat pump system), the quality and uniformity of the air contacting the evaporator unit  130  can be increased. 
     While the various designs in  FIGS. 1-5  are described individually, it is understood that any of the designs described therein can be used alone or in any combination with one another. That is to say, the components presented in  FIGS. 1-5  can be used individually or together with any heat pump system. 
       FIG. 6  illustrates another heat pump system  600 . As shown, the heat pump system  600  can comprise an evaporator assembly  610  (including an evaporator unit  130 ), a compressor  620 , a condenser assembly  630 , and a thermal expansion valve  640 . The evaporator assembly  610 , the condenser assembly  630 , the compressor  620 , and the thermal expansion valve  640  can form a fluid circuit including various additional pipes, valves, and other fitments. The heat pump system  600  can also include components to encourage fluid flow along the fluid circuit, such as a pump  650 , and the heat pump system  600  can also include components to encourage air flow, such as a fan  660 . A heat transfer fluid can be configured to flow through the fluid circuit and undergo heat transfer at both the evaporator assembly  610  and the condenser assembly  630 . 
     While the present disclosure has been described in connection with a plurality of example aspects, as illustrated in the various figures and discussed above, it is understood that other similar aspects can be used, or modifications and additions can be made to the described aspects for performing the same function of the present disclosure without deviating therefrom. For example, in various aspects of the disclosure, methods and compositions were described according to aspects of the presently disclosed subject matter. However, other equivalent methods or composition to these described aspects are also contemplated by the teachings herein. Therefore, the present disclosure should not be limited to any single aspect, but rather construed in breadth and scope in accordance with the appended claims.