Air-cooled heat exchanger and evaporative cooling assembly

Abstract

The present invention provides an air-cooled heat exchanger (10) comprising: an airflow path (18); a fan (14) configured to bias an airflow (16) through the airflow path (18); a coil (20) disposed in the airflow path (18) and configured to receive a first fluid (30) such that the coil (20) effects a first heat exchange relationship between the first fluid (30) and the airflow (16); and an evaporative cooling assembly (12). The evaporative cooling assembly (12) is disposed in the airflow path (18) upstream of the coil (20) with respect to the airflow (16). Further, the evaporative cooling assembly (12) includes a number of microporous hollow fibers (42) configured to receive a second fluid (24) such that the evaporative cooling assembly (12) achieves a second heat exchange relationship between the second fluid (24) and the airflow (16).

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority and the benefit of U.S. Provisional Application Serial No. 63 / 426,259, filed on November 17, 2022, entitled "AIR-COOLED HEAT EXCHANGERS AND EVAPORATIVE COOLING ASSEMBLIES", which is hereby incorporated by reference in its entirety for all purposes. BACKGROUND OF THE DISCLOSURE

[0003] This section is intended to introduce to the reader various aspects of the technology that may be related to various aspects of the present disclosure described below. It is believed that this discussion will help to provide background information to the reader to facilitate a better understanding of the aspects of the present disclosure. Accordingly, it should be understood that these statements should be read in this light and not as an admission of prior art.

[0004] HVAC equipment and standalone cooling devices, such as air handling units, local air coolers, fan walls, and building systems, face many design constraints during their development. The air supplied through such equipment needs to meet strict design specifications, the occupied space should be minimized to save on-site space, and the overall energy consumption should be optimized.

[0005] Therefore, in recent years, the utilization of evaporative cooling technology has increased because it has lower energy consumption compared to other cooling methods. Evaporative coolers lower the temperature of the air stream by introducing water particles and then evaporating them. These components are particularly useful when the inlet air conditions are dry and warm. Conventional evaporative coolers typically include an evaporative medium, components to hold the medium in place, a water supply reservoir, and a water distribution system. Water can be piped from the reservoir to the top of the evaporative medium. As the water drains downward by gravity, some of the water is absorbed into the evaporative medium, and the rest falls back into the water supply reservoir. When air passes through this moist medium, the water evaporates into the air stream, and it is this process that adiabatically cools the air.

[0006] Traditional evaporative coolers have several drawbacks. For example, traditional evaporative coolers are prone to entrainment of moisture. Moisture entrainment is the process by which air passing through an evaporative medium carries excess water droplets into the air, resulting in an unintentional accumulation of water in downstream areas. This process becomes more pronounced at high air velocities. Additionally, the evaporative medium of a traditional evaporative cooler can be oriented generally perpendicular to the airflow passing through the evaporative medium, such that the pressure and velocity distributions across the medium are substantially uniform. While this orientation can reduce moisture entrainment, it increases the size of the traditional evaporative cooler. The size of traditional evaporative coolers is relatively large, which may be compounded by including an enclosure below the evaporative medium that collects water when water is supplied downward by gravity, and using a demister downstream of the evaporative medium airflow and configured to absorb water carried by the air. The demister also creates a pressure drop, resulting in an increased power requirement and a corresponding reduction in the overall efficiency of the traditional evaporative cooler. Water droplets may also contain biological contaminants, such as Legionella bacteria.

[0007] In addition, traditional evaporative coolers may require the use of relatively clean water to reduce mineral deposits, commonly referred to as "scale" buildup. The sensitivity of traditional evaporative coolers to mineral deposits may require time-consuming maintenance techniques and / or excessive water replacement. Moreover, the ability of traditional evaporative coolers to precisely control the supply air temperature and humidity is limited. Generally, the discharged air can be controlled by turning the traditional evaporative cooler on or off according to temperature or humidity requirements. That is, when the traditional evaporative cooler is turned on, water delivery to the evaporative medium can be enabled, and when the evaporative cooler is turned off, water delivery to the evaporative medium can be disabled. However, after the traditional evaporative cooler is switched off, the evaporative medium may remain wet for a period of time, allowing additional cooling and humidification to occur, which contributes to controlling the delay of the traditional evaporative cooler. Once the medium is wet, the amount of water evaporated into the airflow depends entirely on the incoming air conditions.

[0008] Furthermore, the versatility of traditional evaporative cooling media is limited by at least the above-mentioned drawbacks and other drawbacks. That is, embodiments of traditional evaporative cooling media may be limited to a relatively small number of applications that, despite the above-mentioned drawbacks, can operate safely, cost-effectively, and energy-efficiently. For these reasons and others, there is a recognized need for improved systems and methods for evaporative cooling. SUMMARY OF THE INVENTION

[0009] An overview of certain embodiments disclosed herein is set forth below. It should be understood that presenting these aspects is merely to provide a brief overview of these particular embodiments to the reader, and these aspects are not intended to limit the scope of the present disclosure. Indeed, the present disclosure may cover various aspects that may not be set forth below.

[0010] In one embodiment, an air-cooled heat exchanger includes: an air flow path; a fan configured to direct an air flow through the air flow path; a coil disposed in the air flow path and configured to receive a fluid such that the coil effects a first heat exchange relationship between the fluid and the air flow; and an evaporative cooling assembly. The evaporative cooling assembly is disposed upstream of the coil in the air flow path relative to the air flow. Additionally, the evaporative cooling assembly includes a plurality of microporous hollow fibers configured to receive an additional fluid such that the evaporative cooling assembly effects a second heat exchange relationship between the additional fluid and the air flow.

[0011] In another embodiment, a system includes: a vapor compression loop including a condenser coil configured to receive a refrigerant and establish a first heat exchange relationship between the refrigerant and an air flow. The system further includes an additional fluid loop including an evaporative cooling assembly including a plurality of microporous hollow fibers configured to receive a fluid such that the evaporative cooling assembly establishes a second heat exchange relationship between the fluid and the air flow.

[0012] In yet another embodiment, an air-cooled heat exchanger includes: a fan configured to generate an air flow; a coil configured to receive a fluid and establish a first heat exchange relationship between the air flow and the fluid; and a sheet having microporous hollow fibers configured to receive an additional fluid and establish a second heat exchange relationship between the air flow and the additional fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Aspects of the present disclosure may be better understood after reading the following detailed description and with reference to the drawings, in which:

[0014] Figure 1 is a block diagram of an air-cooled heat exchanger having an evaporative cooling assembly in accordance with one aspect of the present disclosure;

[0015] Figure 2 is in accordance with one aspect of the present disclosure Figure 1 a perspective view of a portion of an evaporative cooling assembly (e.g., in an unassembled state);

[0016] Figure 3 is in accordance with one aspect of the present disclosure Figure 2 an enlarged cross-sectional view of the microporous hollow fibers of the evaporative cooling assembly;

[0017] Figure 4 is in accordance with one aspect of the present disclosure and Figure 1 a cross-sectional view of a condenser corresponding to the air-cooled heat exchanger, wherein the condenser includes a condenser coil and an evaporative cooling assembly configured to cool the air flow upstream of the condenser coil;

[0018] Figure 5 Cross-sectional view of the staggered portion of an evaporative cooling assembly according to one aspect of the present disclosure; Figure 1 Cross-sectional view of the in-line portion of an evaporative cooling assembly according to one aspect of the present disclosure;

[0019] Figure 6 Cross-sectional view of the in-line portion of an evaporative cooling assembly according to one aspect of the present disclosure; Figure 1 Perspective view of a portion of an evaporative cooling assembly according to one aspect of the present disclosure, the portion including a pocket in a flexible sheet and an anchor point (e.g., longitudinal rod) disposed in the pocket;

[0020] Figure 7 Process flow diagram of a method of operating a Figure 1 wind air heat exchanger according to one aspect of the present disclosure;

[0021] Figure 8 Schematic illustration of a modular header assembly for an evaporative cooling assembly according to one aspect of the present disclosure, the evaporative cooling assembly including sacrificial layer microporous hollow fibers; Figure 1 Schematic illustration of a roller assembly for an evaporative cooling assembly according to one aspect of the present disclosure, wherein the roller assembly is configured to move a sheet of microporous hollow fibers;

[0022] Figure 9 Schematic illustration of a light shield for an evaporative cooling assembly according to one aspect of the present disclosure; Figure 1 Schematic illustration of a curtain for an evaporative cooling assembly according to one aspect of the present disclosure;

[0023] Figure 10 Schematic illustration of a pleated skirt for an evaporative cooling assembly according to one aspect of the present disclosure; Figure 1 Schematic illustration of a wind air heat exchanger and an evaporative cooling assembly according to one aspect of the present disclosure, wherein the evaporative cooling assembly includes an adiabatic coil adjacent to an additional coil of the wind air heat exchanger;

[0024] Figure 11 Schematic illustration of a wind air heat exchanger and an evaporative cooling assembly according to one aspect of the present disclosure, wherein the evaporative cooling assembly includes an adiabatic coil adjacent to an additional coil of the wind air heat exchanger; Figure 1 Schematic illustration of a light shield for an evaporative cooling assembly according to one aspect of the present disclosure;

[0025] Figure 12 Schematic illustration of a curtain for an evaporative cooling assembly according to one aspect of the present disclosure; Figure 1 Schematic illustration of a pleated skirt for an evaporative cooling assembly according to one aspect of the present disclosure;

[0026] Figure 13 Schematic illustration of a wind air heat exchanger and an evaporative cooling assembly according to one aspect of the present disclosure, wherein the evaporative cooling assembly includes an adiabatic coil adjacent to an additional coil of the wind air heat exchanger; Figure 1 Schematic illustration of a pleated skirt for an evaporative cooling assembly according to one aspect of the present disclosure;

[0027] Figure 14 Schematic illustration of a wind air heat exchanger and an evaporative cooling assembly according to one aspect of the present disclosure, wherein the evaporative cooling assembly includes an adiabatic coil adjacent to an additional coil of the wind air heat exchanger; Figure 1 Schematic illustration of a wind air heat exchanger and an evaporative cooling assembly according to one aspect of the present disclosure, wherein the evaporative cooling assembly includes an adiabatic coil adjacent to an additional coil of the wind air heat exchanger;

[0028] Figure 15 Schematic illustration of a wind air heat exchanger and an evaporative cooling assembly according to one aspect of the present disclosure, wherein the evaporative cooling assembly includes an adiabatic coil adjacent to an additional coil of the wind air heat exchanger; Figure 1Schematic illustration of an air-cooled heat exchanger and an evaporative cooling assembly, wherein the evaporative cooling assembly includes an adiabatic coil disposed between the free cooling coil and the microchannel coil of the air-cooled heat exchanger;

[0029] Figure 16 is a schematic illustration of an air-cooled heat exchanger including a winter inward folding portion according to one aspect of the present disclosure Figure 1 of the air-cooled heat exchanger and the evaporative cooling assembly;

[0030] Figure 17 is a schematic illustration of an air-cooled heat exchanger according to one aspect of the present disclosure including an evaporative cooling assembly (such as an adiabatic coil), which is employed for cooling a variable speed drive (VSD) of the air-cooled heat exchanger; Figure 1 of the air-cooled heat exchanger, and the evaporative cooling assembly is used for cooling a variable speed drive (VSD) of the air-cooled heat exchanger;

[0031] Figure 18 is a schematic illustration of an evaporative cooling assembly according to one aspect of the present disclosure that is employed for cooling inside a variable speed drive (VSD) chassis;

[0032] Figure 19 is a schematic illustration of an evaporative cooling assembly according to one aspect of the present disclosure that is employed to cool a fan motor; and

[0033] Figure 20 is a schematic illustration of an evaporative cooling assembly having anti-freezing features according to one aspect of the present disclosure. Detailed Description

[0034] One or more specific embodiments of the present disclosure will be described below. These described embodiments are merely examples of the currently disclosed technology. Additionally, in the process of striving to provide a concise description of these embodiments, not all features of the actual implementation may be described in the specification. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the specific goals of the developer, such as consistency with system-related and enterprise-related constraints, which may vary from one implementation to another. Furthermore, it should be understood that such development work may be complex and time-consuming, but it is merely a routine task of design, fabrication, and production for those of ordinary skill in the art who benefit from the present disclosure.

[0035] When introducing elements of various embodiments of the present disclosure, the articles "a", "an", and "the" are intended to mean that there is one or more of the elements. The terms "comprising", "including", and "having" are intended to be inclusive and mean that additional elements may exist in addition to the listed elements. Additionally, it should be understood that reference to "one embodiment" or "an embodiment" of the present disclosure is not intended to be construed as excluding the existence of additional embodiments incorporating the recited features.

[0036] The present disclosure relates to an air-cooled heat exchanger having an evaporative cooling assembly. The air-cooled heat exchanger can be employed in a vapor compression or mechanical cooling system (e.g., a chiller), a free cooling system, a liquid immersion system (e.g., at a data center), a residential HVAC system, a commercial HVAC system, another type of suitable HVAC system employing an air-cooled heat exchanger, or any combination thereof. In one embodiment, for example, the air-cooled heat exchanger corresponds to the condenser of a chiller, where the condenser includes a condenser coil configured to place a refrigerant in a heat exchange relationship with an air flow that is deflected past the evaporative cooling assembly and then past the condenser coil via a fan of the condenser.

[0037] The evaporative cooling assembly can include a plurality of microporous hollow fibers configured to receive a flow of a liquid fluid (such as liquid water) for cooling an air flow before delivering the air flow to a component of the air-cooled heat exchanger (such as the condenser coil described above). The wall of each microporous hollow fiber is permeable only to a fluid in vapor form. In other words, the liquid water cannot leave the wall of the microporous hollow fiber to directly mix with the air flow (or other ambient gas flow). When water vapor leaves the wall of the microporous hollow fiber via pores in the wall, it comes into direct contact with the air flow, thereby causing mass and energy transfer. Examples of microporous hollow fibers employed in the context of a membrane contactor panel can be found in the of medium. This is in stark contrast to conventional evaporative media where liquid water wetting the surface of the media is exposed to and directly evaporates into the air flow.

[0038] According to the present disclosure, the evaporative cooling assembly can include a sheet (e.g., a flexible sheet, such as a woven fabric sheet) that contains, holds, embeds, or otherwise employs the microporous hollow fibers. The flexible sheet can enable the formation of a shape of the evaporative cooling assembly that is compatible with the air-cooled heat exchanger. In fact, the air flow velocity and / or the air flow pressure drop typically associated with at least some air-cooled heat exchangers (e.g., condensers) may be relatively large. To handle the air flow velocity and / or the air flow pressure drop associated with the air-cooled heat exchanger, the shape of the evaporative cooling assembly can be designed via the flexible sheet to increase the surface area of the face of the evaporative cooling assembly within a predetermined space.

[0039] As an example, the predetermined space can correspond to an air flow inlet associated with an air-cooled heat exchanger. An evaporative cooling assembly including a flexible sheet having microporous hollow fibers can be disposed (or extend into) the predetermined space corresponding to the air flow inlet. Additionally, the flexible sheet can be wound (or otherwise manipulated) around a support rod such that the evaporative cooling assembly forms an accordion-like, pleated, or serrated cross-sectional shape. In this way, the surface area of the face of the evaporative cooling assembly can be greater than the surface area across the predetermined space corresponding to the air flow inlet. In some embodiments, the surface area of the face of the evaporative cooling assembly can be 2 to 10 times, 4 to 8 times, or 5 to 7 times the surface area across the predetermined space corresponding to the air flow inlet. The above-described shape and / or size design of the evaporative cooling assembly can improve the cooling efficiency and / or cooling capacity of the evaporative cooling assembly while enabling the evaporative cooling assembly to handle or withstand the expected air flow velocity and / or air flow pressure drop associated with the air-cooled heat exchanger. It should be noted that the above-described accordion-like, pleated, or serrated shapes are merely examples according to the present disclosure. Other shapes are possible.

[0040] Furthermore, the above sheet can employ multiple layers of microporous hollow fibers. The thickness of the evaporative cooling assembly as a function of the number of layers of microporous hollow fibers employed in the sheet of the evaporative cooling assembly can be selected based on one or more factors such as the expected air flow velocity and / or air flow pressure drop associated with the air-cooled heat exchanger, the desired cooling efficiency of the evaporative cooling assembly, the desired cooling capacity of the evaporative cooling assembly, or any combination thereof. For example, the evaporative cooling assembly can include a thickness corresponding to: 5 to 40 layers of microporous hollow fibers, 10 to 35 layers of microporous hollow fibers, 15 to 30 layers of microporous hollow fibers, or 20 to 25 layers of microporous hollow fibers. These and other features will be described in detail below with reference to the drawings.

[0041] Figure 1 is a block diagram of an embodiment of an air-cooled heat exchanger 10 having an evaporative cooling assembly 12. For example, the air-cooled heat exchanger 10 can be employed in a vapor compression or mechanical cooling system (e.g., a chiller), a free cooling system, a liquid immersion system (e.g., at a data center), a residential HVAC system, a commercial HVAC system, another type of suitable HVAC system employing an air-cooled heat exchanger, or any combination thereof. As an example, the air-cooled heat exchanger 10 can correspond to the air-cooled condenser of a chiller. Alternatively, the air-cooled heat exchanger 10 can correspond to an air handling unit (AHU)

[0042] Typically, the air-cooled heat exchanger 10 can include a fan 14 configured to direct an air stream 16 (or other ambient gas stream) through an air flow path 18 of the air-cooled heat exchanger 10. The evaporative cooling assembly 12 can be positioned within (or adjacent to) the air-cooled heat exchanger 10 and is configured to cool the air stream 16 before delivering the air stream 16 to components of the air-cooled heat exchanger 10, such as the coil 20. For example, the evaporative cooling assembly 12 can include an inlet 22 configured to receive a first fluid 24, such as liquid water (or a mixture of liquid water and ethylene glycol), and place the first fluid 24 in a heat exchange relationship with the air stream 16. In the illustrated embodiment, the fan 14 is disposed downstream of the coil 20 such that the coil 20 is positioned between the fan 14 and the evaporative cooling assembly 12 with respect to the direction of the air stream 16. However, in other embodiments, the fan 14 can be disposed at different locations.

[0043] As will be described in detail with reference to the following figures, the evaporative cooling assembly 12 can include a plurality of microporous hollow fibers configured to receive the first fluid 24, wherein the wall of each microporous hollow fiber is permeable only to the first fluid 24 in vapor form. In other words, the first fluid 24 in liquid form, such as liquid water, cannot leave the wall of the microporous hollow fiber to directly mix with the air stream 16. Since heat is rejected from the air stream 16 to the first fluid 24, the first fluid 24 in vapor form can leave the wall of the microporous hollow fiber via pores in the wall such that the water vapor directly contacts the air stream 16, thereby causing mass and energy transfer. In addition, the first fluid 24 in liquid form can pass through an outlet 26 of the evaporative cooling assembly 12. In some embodiments, a pump 31 can be employed to circulate the first fluid 24 to and from the evaporative cooling assembly 12 (e.g., via a closed-loop circuit 28 corresponding to the first fluid 24). Additionally, in some embodiments, the circulation of the first fluid 24 can rely at least in part on a thermosiphon.

[0044] As previously described, the evaporative cooling assembly 12 can be employed to cool the air stream 16 before delivering it to the coil 20 (or other fluid flow path). The coil 20 can be configured to receive a second fluid 30, such as a refrigerant, and place the second fluid 30 in a heat exchange relationship with the air stream 16 that has been cooled by the evaporative cooling assembly 12. In this manner, the second fluid 30 can be cooled and / or condensed in the coil 20 via the air stream 16 that has been cooled by the evaporative cooling assembly 12. Alternatively, such as in the context of a particular AHU, the second fluid 30 can cool the air stream 16 as the air stream 16 passes through the coil 20. It should be noted that the first fluid 24 can be substantially different or substantially the same as the second fluid 30. For example, in one embodiment, the first fluid 24 can include water (or a mixture of water and ethylene glycol), and the second fluid 30 can be a refrigerant. In another embodiment, the first fluid 24 and the second fluid 30 can be water (or a mixture of water and ethylene glycol). As used herein, "substantially different" can be meant that the first fluid 24 and the second fluid 30 include different base chemical formulations, while as used herein, "substantially the same" can be meant that the first fluid 24 and the second fluid 30 include the same base chemical formulation (e.g., despite minor differences in specific chemical elements or compounds). In the current context, one of ordinary skill in the art will recognize the meaning of the first liquid 24 and the second fluid 30 being "substantially different", and in the current context, one of ordinary skill in the art will recognize the meaning of the first fluid 24 and the second fluid 30 being "substantially the same".

[0045] Since the air-cooled heat exchanger 10 can be disposed in an external space 34 (e.g., an outdoor space), the air stream 16 can be relatively warm at least during certain seasons of the year. Cooling the air stream 16 via the evaporative cooling assembly 12 before delivering it to the coil 20 can improve the heat exchange efficiency and / or capacity at the coil 20. It should be noted that in some embodiments, a compressor 33 (or other flow biasing device, such as a pump) can be employed to circulate the second fluid 30 to and from the coil 20 (e.g., via a closed-loop circuit 32 corresponding to the second fluid 30). For example, the closed-loop circuit 32 can correspond to a vapor compression or mechanical cooling circuit of a chiller. The air stream 16 can then be output from the air-cooled heat exchanger 10 to the external space 34 (e.g., an outdoor space).

[0046] Figure 2 is Figure 1Schematic perspective view of an embodiment of a portion of the evaporative cooling assembly 12. The evaporative cooling assembly 12 can include a flexible sheet 40 having a plurality of microporous hollow fibers 42 configured to direct a first fluid 24 therethrough. As described in more detail above and below with reference to the following figures, each microporous hollow fiber 42 is permeable only to the first fluid 24 in vapor form. In other words, the first fluid 24 in liquid form cannot leave the walls of the microporous hollow fibers 42.

[0047] The flexible sheet 40 can include a fabric material or any other suitable flexible material (or be formed therefrom) that contains, holds, embeds, or otherwise incorporates the microporous hollow fibers 42. The flexible nature of the flexible sheet 40 can enable the formation of various desired shapes of the evaporative cooling assembly 12. For example, as described in detail with reference to the following figures, it may be desirable to design the shape of the flexible sheet 40 such that the surface area of the face 44 of the evaporative cooling assembly 12 (or its flexible sheet 40) is large enough for the evaporative cooling assembly 12 to handle a relatively large air flow velocity and / or air flow pressure drop associated with the air-cooled heat exchanger having the evaporative cooling assembly 12.

[0048] For example, the face 44 can face or otherwise be traversed by an incoming air flow 16 associated with the air-cooled heat exchanger employing the evaporative cooling assembly 12. As shown, one or more anchors 46 (e.g., longitudinal bars) of the evaporative cooling assembly 12 can be employed to enable the formation of various shapes of the flexible sheet 40. Although the microporous hollow fibers 42 are illustrated in the depicted embodiment as extending transverse to the direction of the anchor points 46, it should be understood that in other embodiments, the microporous hollow fibers 42 can extend parallel to the direction of the anchor points 46. As described with reference to the following figures, the flexible sheet 40 can engage or otherwise interact with one or more anchors 46 to include a bellows-like, pleated, or serrated cross-sectional shape. In accordance with the present disclosure, the shape of the evaporative cooling assembly 12 can be selected to optimize the cooling efficiency and / or cooling capacity of the air flow 16 while reducing or eliminating additional negative impacts associated with the air flow velocity and / or air flow pressure drop corresponding to the air-cooled heat exchanger.

[0049] Another factor that affects the cooling efficiency and / or cooling capacity and the ability of the evaporative cooling assembly 12 to withstand the air flow velocity and / or air flow pressure drop associated with the air-cooled heat exchanger is the thickness 48 of the evaporative cooling assembly 12 (or its flexible sheet 40). For example, the flexible sheet 40 may include a plurality of layers of microporous hollow fibers 42 that pass through the thickness 48 of the flexible sheet 40. Reducing the number of layers of the microporous hollow fibers 42 (and thus the thickness 48 of the flexible sheet 40) can reduce the cooling efficiency and / or cooling capacity of the evaporative cooling assembly 12 while increasing the ability of the evaporative cooling assembly 12 to handle the air flow velocity and / or air flow pressure drop associated with the air-cooled heat exchanger. Increasing the number of layers of the microporous hollow fibers 42 (and thus the thickness 48 of the flexible sheet 40) can increase the cooling efficiency and / or cooling capacity of the evaporative cooling assembly 12 while reducing the ability of the evaporative cooling assembly 12 to handle the air flow velocity and / or air flow pressure drop associated with the air-cooled heat exchanger. Thus, the thickness 48 (and thus the number of layers of the microporous hollow fibers 42) can be selected to balance between the cooling efficiency and / or cooling capacity of the evaporative cooling assembly 12 and the design constraints associated with the air flow velocity and / or air flow pressure drop of the air-cooled heat exchanger. As an example, the thickness 48 may correspond to 5 to 40 layers of microporous hollow fibers 42, 10 to 35 layers of microporous hollow fibers 42, 15 to 30 layers of microporous hollow fibers 42, or 20 to 25 layers of microporous hollow fibers 42.

[0050] Before proceeding to the embodiments of the air-cooled heat exchanger and the example shapes of the corresponding evaporative cooling assembly 12, Figure 3 is in Figure 2 An enlarged cross-sectional view of an embodiment of one of the microporous hollow fibers 42 employed in the evaporative cooling assembly 12. The liquid phase of the first fluid 24 (e.g., liquid water or a liquid mixture of water and ethylene glycol) moves through the microporous hollow fiber lumen 60 and is contained within the volume surrounded by the microporous hollow fiber wall 62. Additionally, the unconditioned air flow 16a is directed at the microporous hollow fibers 42. When environmental conditions permit, the liquid water evaporates into the air flow (outside the microporous hollow fiber wall 62) by undergoing a phase change. The water vapor 64 exits the microporous hollow fiber lumen 60 through a number of pores 66. The water vapor mixes with the unconditioned air flow 16a, thereby providing adiabatic cooling and / or humidification. This results in the conditioned air flow 16b exiting from Figure 2 the surface of the evaporative cooling assembly 12 illustrated in Figure 2 The evaporative cooling assembly 12 of

[0051] Figure 4 is a cross-sectional view of an embodiment of a condenser (e.g., corresponding to Figure 1 the air-cooled heat exchanger 10 ofFigure 1 a condenser coil 20) and an evaporative cooling assembly 12 configured to cool an air stream 16 upstream of the condenser coil 20. For example, the condenser 10 includes an air stream inlet 70 configured to receive the air stream 16, which is deflected through the condenser coil 20 via one or more fans 14. The condenser 10 may be disposed in an outdoor space such that the air stream 16 received at the air stream inlet 70 is an outdoor air stream. In this manner, the evaporative cooling assembly 12 can cool the air stream 16 upstream of the condenser coil 20.

[0052] In the illustrated embodiment, the air stream inlet 70 includes a cross-sectional area 72 (referred to in a particular instance of the present disclosure as the face area of the air stream inlet 70) between a first leg 74 and a second leg 76 of the condenser coil 20, where the first leg 74 and the second leg 76 form a V shape of the condenser coil 20. In a particular embodiment, the V shape may include first and second legs 74 and 76 of equal length. In other embodiments, the first leg 74 may include a first length, the second leg 76 may include a second length, and the first length may be different from the second length. Additionally, in some embodiments, the condenser coil 20 may include an inverted M-shaped cross-section formed by two joined V-shaped cross-sections. That is, it should be understood that in a particular embodiment, the V-shaped cross-section may form a part (e.g., half) of the inverted M-shaped cross-section of the coil 20. Additionally, in embodiments employing an M-shaped cross-section, the inverted M-shaped cross-section may include two joined V-shaped cross-sections that are oriented or rotated 180 degrees as Figure 4 shown to form an inverted version of the inverted M-shaped cross-section

[0053] In the illustrated embodiment, the evaporative cooling assembly 12 includes a flexible sheet 40 that engages respective anchor points 46 of the evaporative cooling assembly 12 to form a shape. As previously described, the flexible sheet 40 may include a plurality of microporous hollow fibers configured to direct a fluid (e.g., liquid water or a liquid mixture of water and ethylene glycol) therethrough. For example, the evaporative cooling assembly 12 may include a liquid inlet 22 and a fluid outlet 26, the liquid inlet being configured to supply a liquid fluid to the microporous hollow fibers of the flexible sheet 40, and the fluid outlet being configured to receive the liquid fluid from the microporous hollow fibers of the flexible sheet 40. The air stream 16 can be conditioned (e.g., cooled and / or humidified) as it passes through the face 77 of the evaporative cooling assembly 12, as described above with reference to Figures 1 to 3 described. As previously described, the condenser 10 may be disposed in an outdoor space. In some embodiments, the microporous hollow fibers of the flexible sheet 40 may be configured to receive a liquid mixture of water and ethylene glycol, where the ethylene glycol provides a level of freeze protection when the ambient temperature is very low.

[0054] In addition, respective anchor points 46 can be employed to engage the flexible sheet 40 of the evaporative cooling assembly 12. The first subset of anchor points 46a can be positioned adjacent to the condenser coil 20, and the second subset of anchor points 46b can be positioned adjacent to the air inlet 70. That is, compared to the second subset of anchor points 46b, the first subset of anchor points 46a can be positioned farther from the air inlet 70, and compared to the first subset of anchor points 46a, the second subset of anchor points 46b can be positioned farther from the condenser coil 20. In some embodiments, the anchor points 46a, 46b (or portions thereof) can be coupled to the wall 79 of the air-cooled heat exchanger 10 (e.g., defining the back of the air-cooled heat exchanger 10 in the illustrated embodiment).

[0055] In addition, each of the anchor points 46a of the first subset can be disposed at a different distance from the air inlet 70. For example, a first distance 78 is shown between the air inlet 70 and one of the anchor points 46a of the first subset, a second distance 80 is shown between the air inlet 70 and another of the anchor points 46a of the first subset, and the first distance 78 is less than the second distance 80. Similarly, each of the anchor points 46b of the second subset can be disposed at a different distance from the air inlet 70. For example, a first distance 82 is shown between the air inlet 70 and one of the anchor points 46b of the second subset, a second distance 84 is shown between the air inlet 70 and another of the anchor points 46b of the second subset, and the first distance 82 is less than the second distance 84. According to the present disclosure, the illustrated cross-sectional shape of the evaporative cooling assembly 12 can be referred to as a bellows shape, a pleated shape, or a serrated shape. However, other shapes are possible.

[0056] As previously described, the respective anchor points 46a, 46b can be longitudinal rods around which or about which the flexible sheet 40 is wound, engaged, or otherwise anchored. In this manner, the flexible sheet 40 can be wound, engaged, or otherwise anchored around the respective anchor points 46a, 46 to form a desired cross-sectional shape, such as the bellows, pleated, or serrated cross-sectional shapes described above. Other cross-sectional shapes are possible. Generally, the cross-sectional shapes according to the present disclosure enable an increase in the surface area of the face 77 of the flexible sheet 40 of the evaporative cooling assembly 12. The shape of the flexible sheet 40 can be designed such that the surface area of the face 77 of the flexible sheet 40 is greater than a threshold surface area, or such that the ratio between the surface area of the face 77 of the flexible sheet 40 and the cross-sectional area 72 of the air inlet 70 is greater than a threshold ratio. For example, in some embodiments, the surface area of the face 77 can be 2 to 10 times, 4 to 8 times, or 5 to 7 times the surface area 72 across the air inlet 70. In this manner, the evaporative cooling assembly 12 can withstand the air flow velocity and / or air flow pressure drop associated with the air flow 16 corresponding to the condenser 10.

[0057] Although Figure 4 only one example of the evaporative cooling assembly 12 corresponding to the condenser coil 20 is illustrated, it should be understood that the condenser 10 may include multiple examples of the condenser coil 20 and multiple examples of the corresponding evaporative cooling assembly 12. In some embodiments employing multiple examples of the evaporative cooling assembly 12, a fluid circuit may be employed, where various examples of the evaporative cooling assembly 12 are arranged in parallel with respect to a corresponding fluid (e.g., liquid water). Additionally, although Figure 4 is an example of a shape that gives rise to a relatively large surface area of the face 77 of the sheet 40 (or the evaporative cooling assembly 12 employing the sheet 40), other shapes are possible.

[0058] Figure 5 is Figure 1 A cross-sectional view of an embodiment of the staggered portion 100 of the evaporative cooling assembly 12. In the illustrated embodiment, the evaporative cooling assembly 12 includes a sheet 40 of microporous hollow fibers, as previously described, where the sheet 40 engages respective anchor points 46 to form a shape. The illustrated embodiment includes a staggered portion 100 having an accordion-like, pleated, or serrated shape. It should be understood that the staggered portion 100 in the illustrated embodiment does not represent the entire sheet 40, but rather a shape that repeats multiple times across a predetermined space (e.g., the air inlet of the condenser). In this particular case, the hollow tube fibers 42 will be oriented within the sheet 40 (e.g., as schematically illustrated in the representative region 75 of the sheet 40 in Figure 5 ). That is, providing Figure 5 is to demonstrate the shape factor of the staggered portion 100 of the sheet 40, as described in detail below.

[0059] Figure 5 shows four face portions 77a, 77b, 77c, 77d of the staggered portion 100 of the sheet 40. The first face portion 77a includes a first height 102 (h1) and a first width 104 (w1), the second face portion 77b includes a second height 106 (h2) and a second width 108 (w2), the third face portion 77c includes a third height 110 (h3) and a third width 112 (w3), and the fourth face portion 77d includes a fourth height 114 (h4) and a fourth width 116 (w4). Additionally, a fifth width 118 (w5) across all four face portions of the first face portion 77a, the second face portion 77b, the third face portion 77c, and the fourth face portion 77d may correspond to Figure 4Part of the air inlet 70 illustrated in the figures and described in detail above. Assuming that the depth of the sheet 40 and the air inlet 70 is the same, the ratio between the surface area of the four face portions 77a, 77b, 77c, 77d and the surface area of the air inlet 70 (e.g., having a fifth width 118 [w5]) is represented by the following equation:

[0060] Equation 1:

[0061] In Figure 5 the illustrated embodiment, the surface area ratio can be between 5 and 9 (e.g., close to 7). In other words, the combined surface area across the four face portions 77a, 77b, 77c, 77d (e.g., corresponding to Figure 5 the staggered portion 100 in Figure 4 is substantially greater than the surface area across the fifth width (w5) (corresponding to Figure 5 the air inlet 70 in Figure 5 ). However, as previously described, it should be noted that the illustrated embodiment is provided merely to demonstrate the form factor of the sheet 40 of the evaporative cooling assembly 12. Generally, the relatively large surface area of the four face portions 77a, 77b, 77c, 77d (e.g., corresponding to Figure 5 the staggered portion 100 in Figure 5 ) improves the response of the evaporative cooling assembly 12 to the air flow velocity and / or air flow pressure drop associated with the air-cooled heat exchanger. That is, the relatively large surface area of the four face portions 77a, 77b, 77c, 77d (e.g., corresponding to Figure 5 the staggered portion 100 in Figure 5 ) can enable the evaporative cooling assembly 12 to handle or withstand the above-mentioned air flow velocity and / or air flow pressure drop.

[0062] Figure 6 is Figure 1 a cross-sectional view of an embodiment of the in-line portion 130 of the evaporative cooling assembly 12. In the illustrated embodiment, the evaporative cooling assembly 12 includes a sheet 40 of microporous hollow fibers, as previously described, wherein the sheet 40 engages respective anchor points 46 to form a shape. The illustrated embodiment includes an in-line portion 130 having an accordion-like, pleated, or serrated shape. It should be understood that the in-line portion 130 in the illustrated embodiment may not represent the entire sheet 40, but rather a shape that is repeated multiple times across a predetermined space (e.g., the air inlet of a condenser). In this particular case, the hollow tube fibers 42 will be oriented in the sheet 40 (e.g., as schematically illustrated in the representative region 85 of the sheet 40 in Figure 5 ). That is, providing Figure 6 is for demonstrating the form factor of the in-line portion 130 of the sheet 40, as described in detail below.

[0063] Figure 6Four face portions 77e, 77f, 77g, 77h of the in-line portion 130 of the sheet 40 are shown. Each of the first face portion 77e, the second face portion 77f, the third face portion 77g, and the fourth face portion 77h includes a common height 132 (h c ), and a common width 134 (w c ). Additionally, the total width 136 (w t ) across all four face portions of the first face portion 77e, the second face portion 77f, the third face portion 77g, and the fourth face portion 77h may correspond to Figure 4 a portion of the air inlet 70 illustrated and described in detail above. Assuming that the depth of the sheet 40 and the air inlet 70 is the same, the ratio between the surface area of the four face portions 77e, 77f, 77g, 77h and the surface area of the air inlet 70 (e.g., having a total width 136 [w t ) is represented by the following equation:

[0064] Equation 2:

[0065] In Figure 6 the illustrated embodiment, the surface area ratio may be between 6 and 10 (e.g., close to 8). In other words, the combined surface area across the four face portions 77e, 77f, 77g, 77h (e.g., corresponding to Figure 6 the in-line portion 130 in t ) is substantially greater than the surface area across the total width (w Figure 4 ), corresponding to Figure 6 the air inlet 70 in Figure 6 ). However, as previously noted, it should be noted that the illustrated embodiment is provided merely to demonstrate the form factor of the sheet 40 of the evaporative cooling assembly 12. Generally, the relatively large surface area of the four face portions 77e, 77f, 77g, 77h (e.g., corresponding to Figure 6 the in-line portion 130 in Figure 6 ) improves the response of the evaporative cooling assembly 12 to the air flow velocity and / or the air flow pressure drop associated with the air-cooled heat exchanger. That is, the relatively large surface area of the four face portions 77a, 77b, 77c, 77d (e.g., corresponding to Figure 6 the in-line portion 130 in Figure 6 ) may enable the evaporative cooling assembly 12 to handle or withstand the above-mentioned air flow velocity and / or air flow pressure drop. As previously pointed out, other shapes are possible.

[0066] In Figure 5 and Figure 6 , an anchor point 46 (e.g., a longitudinal support bar) is used to design the shape of the evaporative cooling assembly 12, and the anchor point is shown outside the sheet 40 of the evaporative cooling assembly 12. However, other arrangements are possible. For example, Figure 7 isFigure 1 Perspective view of an embodiment of a portion of the evaporative cooling assembly 12, the portion including a pocket 150 disposed in a flexible sheet 40 and an anchor point 46 (e.g., longitudinal rod) disposed within the pocket 150. The illustrated embodiment may improve the durability of the evaporative cooling assembly 12 against the air flow velocity and / or air flow pressure drop associated with an air-cooled heat exchanger employing the evaporative cooling assembly 12.

[0067] Figure 8 Illustrates the operation Figure 1 Process flow diagram of an embodiment of a method 200 of operating an air-cooled heat exchanger. In the illustrated embodiment, method 200 includes operating (block 202) a fan to deflect an air flow through the air-cooled heat exchanger. As previously described, the air-cooled heat exchanger may be employed in a vapor compression or mechanical cooling system (e.g., chiller), a free cooling system, a liquid immersion system (e.g., at a data center), a residential HVAC system, a commercial HVAC system, another type of suitable HVAC system, or any combination thereof. Additionally, although the specific embodiment in the presently disclosed embodiment includes a reference to a fan, multiple fans of the air-cooled heat exchanger may be employed.

[0068] Method 200 further includes circulating (block 204) a first fluid (e.g., liquid water) through the evaporative cooling assembly. For example, the first fluid may be circulated through the evaporative cooling assembly by a pump. In some embodiments, the circulation of the first fluid through the evaporative cooling assembly depends at least in part on a thermosiphon. In some embodiments, the evaporative cooling assembly may be integrated within the air-cooled heat exchanger. For example, the evaporative cooling assembly may be disposed in (or extend into) an air flow inlet associated with the air-cooled heat exchanger. Additionally, the evaporative cooling assembly may include, for example, a plurality of microporous hollow fibers formed or embedded, deployed, contained, or otherwise disposed within a flexible sheet (e.g., flexible fabric sheet). The first fluid (e.g., liquid water) may be directed through the microporous hollow fibers, which include a porous wall designed such that the first fluid in vapor form can escape the flow path of the microporous hollow fibers and prevent the first fluid in liquid form from escaping the flow path.

[0069] Method 200 further includes cooling (block 206) the air stream via a first fluid and releasing the first fluid in vapor form from the evaporative cooling assembly and into the air stream. For example, the air stream can be deflected through a flexible sheet such that the air stream contacts an outer surface of the microporous hollow fibers. A portion of the first fluid directed through the microporous hollow fibers can undergo a phase change from liquid to vapor in response to a heat exchange relationship between the first fluid and the air stream. The first fluid in vapor form can escape the microporous hollow fibers via pores of the microporous hollow fibers such that the vapor form directly contacts the air stream, thereby providing adiabatic cooling and / or humidification. As previously described, the shape and / or size of the flexible sheet having the microporous hollow fibers can be designed to enhance cooling efficiency and / or capacity and withstand an air stream velocity and / or an air stream pressure drop corresponding to the air stream generated by a fan of the air-cooled heat exchanger.

[0070] Method 200 further includes circulating (block 208) a second fluid (e.g., a refrigerant) through coils of the air-cooled heat exchanger. For example, the second fluid can be circulated through the coils by a compressor. As previously described, the coils can be condenser coils and the air-cooled heat exchanger can be a condenser. However, other types of air-cooled heat exchangers are possible and are described in detail above with reference to the previous figures. Method 200 further includes passing (block 210) the air stream cooled by the evaporative cooling assembly through the coils. Additionally, method 200 further includes extracting (block 212) heat from the second fluid via the air stream cooled by the evaporative cooling assembly and passing through the coils. In this manner, the second fluid (e.g., a refrigerant) is cooled and / or condensed in the coils via the air stream. The air stream can be output to an external space (e.g., an outer space), and the second fluid can be circulated to other components, such as other components of a heating, ventilation, and / or air conditioning (HVAC) system (e.g., an expansion valve and / or an evaporator).

[0071] Figures 9 to 20 Illustrated are various functions associated with Figure 1 the evaporative cooling assembly 12. In certain embodiments of these embodiments, the evaporative cooling assembly 12 can be employed in the context of Figure 1 the air-cooled heat exchanger 10. In certain other embodiments, the evaporative cooling assembly 12 can be in other contexts. Figures 9 to 2 1 is described in detail below.

[0072] For example, Figure 9Schematic illustration of an embodiment of a modular manifold assembly 220 of an evaporative cooling assembly 12. The modular manifold assembly 220 can include a first manifold 220a (e.g., an inlet manifold) and a second manifold 220b (e.g., an outlet manifold). For example, the first manifold 220a can include: a first inlet 222 configured to distribute a liquid (e.g., water or a mixture of water and ethylene glycol) to a first layer of microporous hollow fibers 224; a second inlet 226 configured to distribute a liquid to a second layer of microporous hollow fibers 228; and a third inlet 230 configured to distribute a liquid to a sacrificial layer of microporous hollow fibers 232). The second manifold 220b can include: a first outlet 234 configured to receive a liquid from the first layer of microporous hollow fibers 224; a second outlet 236 configured to receive a liquid from the second layer of microporous hollow fibers 228; and a third outlet 238 configured to receive a liquid from the sacrificial layer of microporous hollow fibers 232).

[0073] In some embodiments, the evaporative cooling assembly 12 can be arranged such that liquid can flow reversely through the respective layers 224, 228, 232. For example, in another embodiment, the first manifold 220a can include a first inlet 222, an outlet instead of the second inlet 226, and a third inlet 230, while the second manifold 220b can include a first outlet 234, an inlet instead of the second outlet 236, and a third outlet 238.

[0074] Generally, the evaporative cooling assembly 12 can be arranged such that the sacrificial layer of microporous hollow fibers 232 is exposed to the environment (e.g., sunlight or ultraviolet [UV] exposure). That is, the sacrificial layer 232 can protect the first layer 224 and the second layer 228 from UV exposure. In addition, the sacrificial layer 232 can be replaced after a threshold amount of time has passed. In fact, over time, UV exposure may degrade the performance of the sacrificial layer 232. Thus, the sacrificial layer 232 can be replaced as described above. By orienting the evaporative cooling assembly 12 such that only the sacrificial layer 232 protects the first layer 224 and the second layer 228 from UV exposure, the cost of maintaining and / or repairing the evaporative cooling assembly 12 over time is reduced and the performance of the evaporative cooling assembly 12 is improved relative to conventional embodiments.

[0075] Other UV protection techniques are also possible. For example, Figure 10 is for Figure 1Schematic illustration of an embodiment of the roller assembly 250 of the evaporative cooling assembly 12. As previously described, the evaporative cooling assembly 12 may include a sheet 40 of microporous hollow fibers. In the illustrated embodiment, the sheet 40 may form a closed-loop belt. The roller assembly 250 may include a motor 251 that engages the closed-loop belt formed by the sheet 40 and may be configured to rotate the closed-loop belt formed by the sheet 40. The roller assembly 250 may further include respective anchor points 252 around which the closed-loop belt formed by the sheet 40 is disposed. Although the closed-loop belt formed by the sheet 40 engages the anchor points 252 in the illustrated embodiment to form a number of V-shapes (e.g., following the shape of the coils 20 of the air-cooled heat exchanger 10), other shapes are possible (e.g., such as Figures 4 to 6 those illustrated and described above).

[0076] By actuating the closed-loop belt formed by the sheet 40 of microporous hollow fibers, different segments of the sheet 40 may be exposed to UV at different time intervals, thereby reducing the amount of time any given segment is exposed to UV. That is, instead of allowing UV exposure to accumulate in a given area of the sheet 40, the roller assembly 250 enables the distribution of the overall UV exposure through the sheet 40 of microporous hollow fibers. In some embodiments, the actuation of the motor 251 may be controlled by a controller 254 (e.g., having a processor 256 and a memory 258) based on a timer or a sensor 260. For example, the sensor 260 may be a UV sensor, a light sensor, or any other sensor configured to measure a characteristic indicative of UV exposure. Additional features for protecting the evaporative cooling assembly 12 from UV exposure are possible. For example, Figure 11 is a schematic illustration of a light shield 262 that may be employed in the Figure 1 evaporative cooling assembly 12, wherein the light shield 262 is arranged to at least partially prevent the evaporative cooling assembly 12 (or a portion thereof) from being exposed to UV. As shown, the light shield 262 may include an opaque or translucent material 264. In some embodiments, the material 264 may be selected to allow air flow therethrough. It should be noted that in a particular embodiment, the light shield 262 may surround or enclose the evaporative cooling assembly 12. Additionally or alternatively, the light shield 262 may be arranged to cover a portion of the evaporative cooling assembly 12 that would otherwise be exposed to sunlight.

[0077] Other features of the evaporative cooling assembly 12 (e.g., those that may be employed in any of the previously described embodiments) are possible. For example, Figure 12 is Figure 1Schematic illustration of an embodiment of the curtain 270 of the evaporative cooling assembly 12. The curtain 270 can form a sheet of the above-described microporous hollow fibers. That is, the curtain 270 can include microporous hollow fibers embedded in, contained within, or otherwise integrated therein. As shown, the curtain 270 can be positioned around an air-cooled heat exchanger (such as Figure 1 the air-cooled heat exchanger 10). In addition, an inlet header 272 and an outlet header 274 can be coupled to the curtain 270 to supply liquid to and receive liquid from the microporous hollow fibers of the curtain 270, respectively. Although in the illustrated embodiment, the inlet header 272 is illustrated at the top of the unit and the outlet header 274 is illustrated at the bottom of the unit, it should be understood that in another embodiment, the positions of the inlet header 272 and the outlet header 274 can be exchanged. In addition, in a particular embodiment, a blocker 276 can extend across the bottom of the air-cooled heat exchanger 10 such that, before delivering at least a portion of the air stream to the coil 20, the air stream passing through the air-cooled heat exchanger 10 is first forced through the curtain 270 (and thus through its microporous hollow fibers).

[0078] According to the present disclosure, the curtain 270 can be flexible such that it can be lifted, rolled up, or otherwise removed from the air stream path of the air-cooled heat exchanger 10 during off-peak seasons. That is, the curtain 270 can be positioned to cool the air stream during peak seasons but removed during off-peak seasons such that it does not create an unnecessary pressure drop when its use is not required or otherwise employed in the air-cooled heat exchanger 10.

[0079] Figure 13 is Figure 1 Schematic illustration of an embodiment of the pleated skirt 280 of the evaporative cooling assembly 12. In the illustrated embodiment, and unlike the curtain 270 in Figure 12 , the pleated skirt 280 (e.g., having microporous hollow fibers) can be positioned below the coil 20 of the air-cooled heat exchanger 10 (e.g., adjacent to the inlet of the coil 20). The pleated skirt 280 can increase the surface area of the evaporative cooling assembly 12. As shown, the inlet header 272 and the outlet header 274 can be fluidly coupled to respective microporous hollow fibers of the pleated skirt 280 for liquid distribution to and from the microporous hollow fibers. A blocker 276, as in Figure 12 , can be employed to block the bottom of the unit such that the air stream going to the coil 20 is first forced through the pleated skirt 280 of the evaporative cooling assembly 12. Additional blockers 282 can be employed at each instance of the coil 20 such that the air stream does not bypass the pleated skirt 280 before being delivered to the coil 20.

[0080] Figure 14 is Figure 1Schematic illustration of an embodiment of an air-cooled heat exchanger 10 and an evaporative cooling assembly 12, where the evaporative cooling assembly 12 includes an adiabatic coil 300 adjacent to, for example, the coil 20 of the air-cooled heat exchanger 10. The adiabatic coil 300 may include the aforementioned web of microporous hollow fibers (e.g., sheet 40) coupled to an input / output header. As shown, the adiabatic coil 300 may contact the coil 20 of the air-cooled heat exchanger 10. In another embodiment, a gap may be provided between the adiabatic coil 300 and the coil 20. As shown, an air flow 301 may pass through the adiabatic coil 300 and then through the coil 20.

[0081] In addition, in some embodiments, a free cooling coil may be employed in the air-cooled heat exchanger 10. For example, Figure 15 is Figure 1 Schematic illustration of an embodiment of an air-cooled heat exchanger 10 and an evaporative cooling assembly 12, where the evaporative cooling assembly 12 includes an adiabatic coil 300 disposed between a free cooling coil 302 and a coil 20 (e.g., a microchannel coil) of the air-cooled heat exchanger 10. The free cooling coil 302 may be configured to receive a liquid, such as water or a mixture of ethylene glycol and water. Additionally, the operation of the free cooling coil 302 may be selectively enabled and disabled based on environmental conditions near the air-cooled heat exchanger 10. Additionally or alternatively, the reliance on the free cooling coil 302 may be modulated based on environmental conditions (e.g., between full load, various partial loads, and no load). Further, in the illustrated embodiment, the adiabatic coil 300 may be sandwiched between the free cooling coil 302 and the microchannel coil 20. In this way, the adiabatic coil 300 can be protected from UV exposure. As shown, an air flow 301 may pass through the free cooling coil 302, then through the adiabatic coil 300, and then through the coil 20.

[0082] Figure 16 is an Figure 1 Schematic illustration of an embodiment of an air-cooled heat exchanger 10 and an evaporative cooling assembly 12 including a winter inward fold 310. The winter inward fold 310 is formed by one or more adiabatic coils 300 of, for example, the evaporative cooling assembly 12. In the illustrated embodiment, the winter inward fold 310 is in a folded position such that the adiabatic coils 300 converge along a centerline 312 (e.g., symmetric) corresponding to the coil 20. In this way, for example, when environmental conditions render the evaporative cooling assembly 12 (and the corresponding adiabatic coils 300) unnecessary (e.g., during winter), the adiabatic coils 300 can be removed from the flow path of the air going to and through the coil 20. Figure 16The dashed line in [it] illustrates the operating position 314 of the evaporative cooling assembly 12 when environmental conditions make it desirable to use the evaporative cooling assembly 12 (e.g., in summer, autumn, and / or spring). That is, the operating position 314 illustrates a situation in which the winter inward fold 310 is actuated outwardly such that the adiabatic coil 300 resides in the flow path of the air going to and passing through the coil 20. In this way, in the operating position 314, the adiabatic coil 300 can receive the air flow before the air flow is delivered to the coil 20. It should be noted that the winter inward fold 310 can be actuated manually (e.g., by an operator) or automatically (e.g., via a control system).

[0083] Figure 17 which includes an evaporative cooling assembly 12 (such as an adiabatic coil) Figure 1 is a schematic illustration of an embodiment of an evaporative cooling assembly 10 that includes an evaporative cooling assembly 12 (such as an adiabatic coil) and is employed for cooling a variable speed drive (VSD) 312 of an air-cooled heat exchanger 10. In the illustrated embodiment, the evaporative cooling assembly 12 includes a first header 272 (e.g., an inlet header), a second header 274 (e.g., an outlet header), and a sheet 40 of microporous hollow fibers extending between the inlet header 272 and the outlet header 274. The evaporative cooling assembly 12 is arranged to provide cooling to the VSD 312 corresponding to a fan 14 (e.g., a fan motor). It should be noted that conventionally, an ethylene glycol mini-coil can be used to cool the VSD. According to the present disclosure, instead of or in addition to conventional cooling features, the presently disclosed embodiments of the evaporative cooling assembly 12 can be employed to cool the VSD 312. Further, although only one instance of the evaporative cooling assembly 12 is shown in the illustrated embodiment, it should be noted that multiple instances of the evaporative cooling assembly 12 (e.g., one for each instance of the VSD 312) can be employed in the air-cooled heat exchanger 10.

[0084] In addition, Figure 18 is a schematic illustration of an embodiment of an evaporative cooling assembly 12 that is employed for cooling inside a variable speed drive (VSD) chassis 314. As previously referenced Figures 4 to 6 described, anchor points 46 can be employed to arrange the evaporative cooling assembly 12, such as the sheet 40 of microporous hollow fibers corresponding to the evaporative cooling assembly 12, in a suitable shape (e.g., a zigzag or bellows shape) for providing an appropriate level or amount of cooling (e.g., to the VSD chassis 314). The inlet 22 can supply liquid (e.g., water or a mixture of ethylene glycol and water) to the sheet 40 of microporous hollow fibers, and the outlet 26 can receive liquid from the sheet 40 of microporous hollow fibers.

[0085] Additional uses of the evaporative cooling assembly 12 are also possible. For example, Figure 19FIG. 0 is a schematic illustration of an embodiment of an evaporative cooling assembly 12 employed to cool a fan motor 320 having a shaft 322 configured to be coupled to a fan (e.g., one of the fans 14 illustrated in a previous embodiment). The evaporative cooling assembly 12 may include a sheet 40 of microporous hollow fibers fluidly coupled to an inlet manifold 272 and an outlet manifold 274, as previously described with respect to a particular embodiment of the present disclosure. It should be noted that in other embodiments, the positions of the inlet manifold 272 and the outlet manifold 274 may be reversed or otherwise arranged. For example, in another embodiment, both the inlet manifold 272 and the outlet manifold 274 may be positioned adjacent to a portion of the shaft 322 illustrated in FIG. Figure 19 on a side of the motor 320. In the illustrated embodiment, the evaporative cooling assembly 12 may be referred to as a cooling blanket. Although the evaporative cooling assembly 12 forms a cooling blanket around the fan motor 320 in FIG. Figure 14 , cooling blankets may be employed in other HVAC components such as compressors or pumps. As previously described, in the winter or when ambient temperatures are otherwise very low, especially outdoor HVAC components may be vulnerable to freezing conditions, especially in the presence of liquid water. In the case of the presently disclosed evaporative cooling assembly 12, which may include a fabric material comprising a plurality of microporous hollow fibers, freezing may cause the fabric material to harden and possibly break. Figure 19 a portion of the shaft 322 illustrated in FIG. Figure 19 . In the illustrated embodiment, the evaporative cooling assembly 12 may be referred to as a cooling blanket. Although the evaporative cooling assembly 12 forms a cooling blanket around Figure 14 the fan motor 320 in FIG. Figure 14 , cooling blankets may be employed in other HVAC components such as compressors or pumps

[0086] As previously mentioned, in the winter or when ambient temperatures are otherwise very low, especially outdoor HVAC components may be vulnerable to freezing conditions, especially in the presence of liquid water. In the case of the presently disclosed evaporative cooling assembly 12, which may include a fabric material comprising a plurality of microporous hollow fibers, freezing may cause the fabric material to harden and possibly break. Figure 20 FIG. 9 is a schematic illustration of an embodiment of an evaporative cooling assembly 12 having various features configured to prevent such freezing conditions. The evaporative cooling assembly 12 includes, for example, a sheet 40 of microporous hollow fibers (e.g., a fabric material), a ribbon 330, and a cylinder 332. Before ambient conditions reach freezing conditions, the sheet 40 of microporous hollow fibers may be rolled up via the cylinder 332 and prevented from operating. When the ambient temperature increases and / or otherwise requires the evaporative cooling assembly 12, the cylinder 332 and / or the sheet 40 may be heated (e.g., via a heater 334 such as an electric heater) to ensure that any freezing is eliminated. After heating, the sheet 40 may be unrolled from the cylinder 332 to an operating position, as shown, and operation of the evaporative cooling assembly 12 may then be enabled (e.g., liquid may be provided to the sheet 40 of microporous hollow fibers).

[0087] Technical effects associated with the presently disclosed embodiments include increased cooling efficiency and / or capacity of air-cooled heat exchangers such as condensers, reduced energy consumption associated with operating air-cooled heat exchangers, etc.

[0088] The scope of the present disclosure is not limited to the specific embodiments described herein. Indeed, various modifications of the present disclosure will become apparent to those skilled in the art in light of the foregoing description. Such modifications are intended to fall within the scope of the appended claims.

[0089] Although only certain features and embodiments of the present disclosure are illustrated and described, many modifications and variations can be contemplated by those skilled in the art without materially departing from the novel teachings and advantages of the subject matter recited in the claims, such as variations in the size, dimensions, structure, shape and proportions of the various elements, parameter values (including temperature and pressure), installation arrangements, use of materials, color, orientation, etc. The order or sequence of any process or method steps can be changed or re-ordered according to alternative embodiments. Accordingly, it is to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the present disclosure. In addition, for the sake of brevity in the description of exemplary embodiments, not all features of actual implementations may be described, such as those features that are not relevant to the currently contemplated best mode of practicing the present disclosure or those features that are not relevant to achieving the claimed disclosure. It should be understood that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such development work may be complex and time-consuming, but for those of ordinary skill in the art who benefit from the present disclosure, these are routine tasks of design, fabrication, and production without undue experimentation.

[0090] The technologies presented and claimed herein refer to and are applied to substantial objects and specific instances with a practical nature, which substantially improve the technical field of the present invention and are thus not abstract, intangible, or purely theoretical. Further, if any claim appended to the end of this specification contains one or more elements designated as "means for [performing][function]..." or "step for [performing][function]...", then such elements are intended to be construed in accordance with 35 U.S.C. 112(f). However, for any claim item containing elements designated in any other manner, such elements are not intended to be construed in accordance with 35 U.S.C. 112(f).

[0091] All patents, applications, publications, test methods, literature, and other materials cited herein are hereby incorporated by reference.

Claims

1. An air-cooled heat exchanger, comprising: An air flow path; A fan configured to deflect air flow through the air flow path; A coil disposed in the air flow path and configured to receive a fluid, such that the coil implements a first heat exchange relationship between the fluid and the air flow; and An evaporative cooling assembly disposed upstream of the coil in the air flow path with respect to the air flow, wherein The evaporative cooling assembly includes a plurality of microporous hollow fibers configured to receive an additional fluid, such that the evaporative cooling assembly implements a second heat exchange relationship between the additional fluid and the air flow.

2. The air-cooled heat exchanger according to claim 1, wherein each of the plurality of microporous hollow fibers includes: A fluid flow path configured to receive a liquid corresponding to the additional fluid, such that the air flow passing through the microporous hollow fiber generates vapor from the liquid; And A plurality of pores configured to release the vapor into the air flow and prevent the liquid from escaping the fluid flow path.

3. The air-cooled heat exchanger according to claim 1, comprising: A plurality of anchor points; And A flexible sheet including the plurality of microporous hollow fibers of the evaporative cooling assembly, wherein the flexible sheet engages the plurality of anchor points such that the evaporative cooling assembly includes a bellows-shaped, corrugated, or serrated cross-sectional shape.

4. The air-cooled heat exchanger according to claim 1, comprising: An inlet configured to supply the additional fluid to the plurality of microporous hollow fibers of the evaporative cooling assembly; And An outlet configured to receive the additional fluid from the plurality of microporous hollow fibers of the evaporative cooling assembly.

5. The air-cooled heat exchanger according to claim 1, wherein the coil is disposed between the fan and the evaporative cooling assembly with respect to the air flow.

6. The air-cooled heat exchanger according to claim 1, wherein the coil includes a condenser coil configured to receive a refrigerant corresponding to the fluid.

7. The air-cooled heat exchanger according to claim 1, wherein the coil includes a V-shaped cross-section.

8. The air-cooled heat exchanger according to claim 1, comprising a light shield configured to prevent the evaporative cooling assembly or a portion thereof from being exposed to ultraviolet (UV) light.

9. The air-cooled heat exchanger according to claim 1, wherein the fluid is substantially different from the additional fluid.

10. The air-cooled heat exchanger according to claim 1, wherein the air-cooled heat exchanger is configured to discharge the air flow to the ambient atmosphere.

11. The air-cooled heat exchanger according to claim 1, wherein the coil includes an inverted M-shaped cross-section.

12. A system, comprising: A vapor compression circuit including a condenser coil configured to receive a refrigerant and establish a first heat exchange relationship between the refrigerant and an air flow; And An additional fluid circuit, comprising an evaporative cooling assembly, the evaporative cooling assembly comprising a plurality of microporous hollow fibers configured to receive a fluid such that the evaporative cooling assembly establishes a second heat exchange relationship between the fluid and the air stream.

13. The system according to claim 12, comprising a fan configured to generate the air stream.

14. The air-cooled heat exchanger according to claim 12, wherein the evaporative cooling assembly is upstream of the condenser coil with respect to the direction of the air stream.

15. The system according to claim 12, comprising: a compressor of the vapor compression circuit, wherein the compressor is configured to bias the refrigerant to flow through the condenser coil; and a pump of the additional fluid circuit, wherein the pump is configured to bias the fluid to flow through the evaporative cooling assembly.

16. The system according to claim 12, wherein each of the plurality of microporous hollow fibers comprises: a fluid flow path configured to receive a liquid corresponding to the fluid such that the air stream passing through the microporous hollow fiber generates vapor from the liquid; and a plurality of pores configured to release the vapor into the air stream and prevent the liquid from escaping the fluid flow path.

17. The system according to claim 12, wherein the condenser coil has a V-shaped cross-section or an inverted M-shaped cross-section.

18. An air-cooled heat exchanger, comprising: a fan configured to generate an air stream; a coil configured to receive a fluid and establish a first heat exchange relationship between the air stream and the fluid; and a sheet having a plurality of microporous hollow fibers configured to receive an additional fluid and establish a second heat exchange relationship between the air stream and the additional fluid.

19. The air-cooled heat exchanger according to claim 18, wherein the coil is disposed between the fan and the sheet.

20. The air-cooled heat exchanger according to claim 18, wherein the sheet comprises a flexible sheet having the plurality of microporous hollow fibers, and the flexible sheet comprises an accordion-like, pleated or serrated cross-sectional shape.

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