Air cooled heat exchanger with intermediate airflow module

Abstract

An air cooled heat exchange assembly is disclosed. The air cooled heat exchange assembly may include: a first heat exchange module configured to receive air and to transfer heat from a working fluid to the air; a second heat exchange module positioned adjacent to the first heat exchange module, the second heat exchange module being configured to receive air and to transfer heat from the working fluid to the air; a first fan module positioned adjacent to the second heat exchange module; and a second fan module positioned between the first heat exchange module and the second heat exchange module, the second fan module being configured to draw air through the first heat exchange module and to discharge the air toward the first fan module. Other aspects are described and claimed.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 774,436, filed on Mar. 19, 2025, which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] Aspects of the present disclosure relate generally to air-cooled heat exchangers used in refrigeration or cooling, or in heating, ventilation, and air conditioning (HVAC). More particularly, the present disclosure relates to multi-level air-cooled heat exchangers incorporating one or more intermediate fan modules.BACKGROUND

[0003] Air-cooled heat exchangers are used in refrigeration, industrial cooling, and HVAC systems. High heat loads, for example in data center environments, together with water use restrictions, have increased reliance on air cooled heat rejection systems. Some of these systems include heat exchange units with tube and fin coils as well as fans located at the top of the unit to draw air upward. To increase capacity within a limited footprint, manufacturers have introduced vertically stacked coil sections. In some arrangements of these stacked heat exchange systems, a single top fan section pulls air through all levels. While useful, these systems can benefit from greater airflow and / or control over airflow.

[0004] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art, or suggestions of the prior art, by inclusion in this section. Further, the scope of the disclosure is defined by the attached claims and not by the ability to solve a particular problem, includes the problems described above.SUMMARY OF THE DISCLOSURE

[0005] According to certain aspects of the disclosure, one or more fan assemblies may be positioned between vertically stacked heat exchanger coil modules to assist movement of air through the stacked sections and to improve airflow distribution across the heat exchanger.

[0006] In one aspect, an air cooled heat exchange assembly is provided. The air cooled heat exchange assembly may include: a first heat exchange module configured to receive air and to transfer heat from a working fluid to the air; a second heat exchange module positioned adjacent to the first heat exchange module, the second heat exchange module being configured to receive air and to transfer heat from the working fluid to the air; a first fan module positioned adjacent to the second heat exchange module; and a second fan module positioned between the first heat exchange module and the second heat exchange module, the second fan module being configured to draw air through the first heat exchange module and to discharge the air toward the first fan module.

[0007] In another aspect, a method of using a heat exchange assembly is provided. The heat exchange assembly may include a first heat exchange module, a second heat exchange module positioned adjacent to the first heat exchange module, a second fan module positioned between the first heat exchange module and the second heat exchange module, and a first fan module positioned adjacent to the second heat exchange module, and the method may include: drawing ambient air through the first heat exchange module to transfer heat from a working fluid to the ambient air; operating the second fan module to draw air that has passed through the first heat exchange module and to add airflow energy between the first heat exchange module and the second heat exchange module; and operating the first fan module to draw air through the second heat exchange module and to exhaust the air from the heat exchange assembly.

[0008] In yet another aspect, an air cooled heat exchange assembly is provided. The air cooled heat exchange assembly may include: at least two heat exchange modules arranged such that air passes sequentially through the at least two heat exchange modules, each heat exchange module including at least one heat exchange coil configured to transfer heat from a working fluid to the air; a first airflow module positioned to move air through the at least two heat exchange modules; and at least one additional airflow module including one or more fans configured to: (i) draw air that has passed through at least one of the at least two heat exchange modules, and (ii) discharge the air toward another of the at least two heat exchange modules, wherein the at least one additional airflow module is positioned at a location within the air cooled heat exchange assembly selected from: (i) between adjacent heat exchange modules of the at least two exchange modules, and (ii) within at least one heat exchange module of the at least two heat exchange modules.

[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the disclosed embodiments, and, together with the description, serve to explain the principles of the disclosed embodiments. There are many aspects and embodiments described herein.

[0011] FIG. 1A depicts an isometric view of an exemplary air cooled heat exchanger unit.

[0012] FIG. 1B depicts a front view of a vertically stacked air cooled heat exchanger unit.

[0013] FIG. 2 depicts a front view of an air cooled heat exchange assembly including an intermediate fan module, according to one or more aspects of the present disclosure.

[0014] FIG. 3 depicts an exploded view of the air cooled heat exchange assembly illustrating an embodiment in which the intermediate fan module includes a single large diameter fan positioned between vertically stacked heat exchange modules, according to one or more embodiments of the present disclosure.

[0015] FIG. 4 depicts an exploded view of the air cooled heat exchange assembly illustrating an embodiment in which the intermediate fan module includes a plurality of fans arranged in a single row between vertically stacked heat exchange modules, according to one or more embodiments of the present disclosure.

[0016] FIG. 5 depicts an exploded view of the air cooled heat exchange assembly illustrating an embodiment in which the intermediate fan module includes a plurality of fans arranged in rows between vertically stacked heat exchange modules, according to one or more embodiments of the present disclosure.

[0017] FIG. 6 depicts an embodiment in which one or more fan modules are integrated within a heat exchange module, according to one or more embodiments of the present disclosure.

[0018] FIG. 7 depicts an embodiment in which one or more fan modules are oriented at an angle along inward-facing surfaces of heat exchange coils, according to one or more embodiments of the present disclosure.

[0019] FIG. 8 depicts an embodiment of an air cooled heat exchange assembly having a plurality of vertically stacked heat exchange modules and one or more intermediate airflow modules positioned at one or more elevations within the assembly, according to one or more embodiments of the present disclosure.

[0020] FIG. 9 depicts a front view of the air cooled heat exchange assembly illustrating airflow when both the intermediate fan module and the discharge fan section are operating, according to one or more embodiments of the present disclosure.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The terminology used below may be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the present disclosure. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.

[0022] In this disclosure, the term “based on” means “based at least in part on.” The singular forms “a,”“an,” and “the” include plural referents unless the context dictates otherwise. The term “exemplary” is used in the sense of “example” rather than “ideal.” The terms “comprises,”“comprising,”“includes,”“including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article or apparatus that comprises a list of elements does not necessarily include only those elements, and may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. Relative terms, such as “about,”“approximately,”“substantially,” and “generally,” are used to indicate a possible variation of ±10% of a stated or understood value. In addition, the term “between” used in describing ranges of values is intended to include the minimum and maximum values described in that range. The use of the term “or” in the claims and specification is used to mean “and / or” unless either explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and / or.” As used herein “another” may mean at least a second or more.

[0023] As used herein, the term “fan” refers to any air moving device configured to impart motion to air, including but not limited to axial fans, centrifugal fans, mixed flow fans, plug fans, blower wheels, or similar air moving mechanisms, and may be driven by electric motors, electronically commutated motors, belt driven arrangements, direct drive arrangements, or other drive systems. The term “heat exchanger coil” may refer to any fluid to air heat transfer structure, including tube and fin coils, microchannel coils, plate fin coils, or other extended surface heat transfer assemblies carrying refrigerant, water, glycol solutions, dielectric fluids, or other working fluids. The term “module” may refer to a structural section or portion of a heat exchange assembly that may be manufactured, transported, or installed as a unit and that may include one or more coils, fans, plenums, housings, or support members. Relative positional terms such as “top,”“bottom,”“upper,”“lower,” and “intermediate” are used for convenience of description with reference to example orientations and are not intended to limit the orientation of the equipment during manufacture, transport, or operation.

[0024] Vertically stacked air cooled heat exchangers may include multiple coil sections arranged one above another within a single structural envelope. Double and triple stacked configurations are examples of this approach. Each level of the system may include a separate heat exchange module or fan module, with each heat exchange module including one or a plurality of heat exchange coil sections, or panels.

[0025] FIGS. 1A and 1B show an exemplary configuration of a double stack (e.g., two unitary and separately shippable modules) heat exchange system including upper and lower heat exchange modules that are connected to each other to form a single heat exchange system. These systems may include a fan section located at the top of the unit that pulls air through all stacked coil sections simultaneously. The fan section may be integral and unitary with upper heat exchange module. The increased coil surface area, in comparison with single-level heat exchange systems, may increase thermal capacity and performance.

[0026] As shown in FIGS. 1A and 1B, an air cooled heat exchange assembly 100 may be provided with an upper fan module (also referring to herein as a “discharge fan section”) 105 and a lower or intermediate fan module 206. Intermediate fan module 206 may be located at about a center-point between a lower module with a lower heat exchange coil 150 and an upper module with an upper heat exchange coil 152. While intermediate fan module 206 is shown in an exemplary location between coils 150 and 152, optional module locations 205 and 207 are shown in FIG. 1B.

[0027] Module location 205 for intermediate fan module 206 may partially or entirely overlap lower heat exchange coil 150 or may otherwise position an entirety or a portion of intermediate fan module 206 within the lower module. Location 207 for intermediate fan module 206 may partially or entirely overlap upper heat exchange coil 152 of the upper module. Location 207 or 205 may be utilized to reduce the overall height of heat exchange assembly 100.

[0028] FIG. 2 illustrates an air cooled heat exchange assembly 200 (“assembly”) with multiple heat exchange modules that are stacked to be vertically adjacent to each other. The assembly 200 may include an upper heat exchange module 202 (e.g., a “first” heat exchange module) positioned above a lower heat exchange module 204 (e.g., an “intermediate” or “second” heat exchange module). An intermediate fan module 206 (e.g., a “second” fan module) may be located between the upper heat exchange module 202 and the lower heat exchange module 204. A discharge fan section 208 (e.g., a “first” fan module) may be positioned at an upper portion of the assembly 200.

[0029] The lower heat exchange module 204 may include one or more fluid to air heat exchanger coils 250 arranged to receive ambient air through exterior coil surfaces. The upper heat exchange module 202 may similarly include one or more heat exchanger coils 252. The coils 250, 252 of the modules 202 and 204 may be tube and fin coils, microchannel coils, or other extended surface heat transfer structures configured to transfer heat from a circulating working fluid to air. The modules 202 and 204 may be supported by a structural frame and may be vertically aligned so that air passing through the lower heat exchange module 204 may subsequently pass through the upper heat exchange module 202.

[0030] The intermediate fan module 206 may be positioned within a plenum 210 between the modules 202 and 204. The plenum 210 may extend substantially across an entire width of the assembly 200 and may define an airflow chamber through which air exiting the lower heat exchange module 204 passes prior to entering the upper heat exchange module 202. The intermediate fan module 206 may be at least partially enclosed by housing panels, shrouds, or other types of structural members so that air moved by the intermediate fan module 206 is primarily drawn from air exiting the lower heat exchange module 204 rather than directly from ambient surroundings. In operation, the intermediate fan module 206 may pull air through the lower heat exchange module 204 and discharge the air toward the upper heat exchange module 202, as further illustrated and described herein.

[0031] The intermediate fan module 206 may include one or more fans. The intermediate fan module 206 may include one or more axial fans. In other embodiments, the intermediate fan module 206 may include centrifugal fans, plug fans, mixed flow fans, blower wheels, or combinations thereof. The fans of the intermediate fan module 206 may be driven by electric motors including direct drive motors, belt driven motors, electronically commutated motors, or other suitable motor arrangements.

[0032] The intermediate fan module 206 may be mounted directly to frame members separating the modules 202 and 204 (e.g., in a separate housing that extends from module 202 to module 204) or may be supported by a dedicated fan deck or panel. In other configurations, intermediate fan module 206 is integrated within module 202 or module 204 (e.g., as described with respect to locations 205 and 207 in FIG. 1B). The intermediate fan module 206 may be positioned approximately at a center point in a vertical direction between the modules 202 and 204, although other vertical placements may be used. For example, the intermediate fan module 206 may be positioned closer to the lower heat exchange module 204 to increase airflow through the lower module, or closer to the upper heat exchange module 202 to adjust airflow distribution depending on operating conditions.

[0033] The housing that contains fans of intermediate fan module 206 may partially or entirely surround the fans of module 206. In one example, all four sides of intermediate fan module 206 may be enclosed by a housing such that an entirety of the air received by heat exchange modules 250 and 252 passes through the corresponding heat exchange coils. In other aspects, one, two, three, or four sides of the housing for intermediate fan module 206 may be open or at least partially open. For example, in the illustrated configuration, a pair of laterally-opposite side walls are formed on opposite sides of the fans of intermediate fan module 206, with an opening being formed between the side walls.

[0034] The intermediate fan module 206 may include inlet bellmouths, venturi rings, or shrouds configured to guide air into the fan. Downstream of the fans, diffusers, turning vanes, or flow straighteners may be provided to direct airflow toward the upper heat exchange module 202. Such airflow management components may reduce recirculation and may improve uniform airflow distribution across the coil surfaces of the upper heat exchange module 202.

[0035] The intermediate fan module 206 may be arranged in a variety of configurations within the assembly 200, as illustrated in the exploded views of FIGS. 3-5. Different fan configurations may be selected based on desired airflow volume, static pressure capability, redundancy, serviceability, or manufacturing considerations, for example.

[0036] As shown in exemplary assembly 300 in FIG. 3, the intermediate fan module 206 may include a single large diameter fan 302 positioned centrally, in length and width directions, within the plenum 210 between the upper heat exchange module 202 and the lower heat exchange module 204. The single large diameter fan 302 may extend across a portion or an entirety of the plan area between the modules 202 and 204. In this configuration, the single large diameter fan 302 may provide relatively high airflow at moderate static pressure while minimizing the number of rotating components. The use of a single large diameter fan 302 may simplify controls and electrical connections and may reduce the number of service points associated with the intermediate fan module 206.

[0037] As illustrated in exemplary assembly 400 in FIG. 4, the intermediate fan module 206 may alternatively include a plurality of fans 402 arranged in a single row extending across the width of the plenum 210. The fans 402 may be positioned side by side in a front-to-rear direction of the assembly 200 so that each fan 402 moves air through a corresponding portion of the lower heat exchange module 204 and into a corresponding portion of the upper heat exchange module 202. The use of multiple smaller fans 402 may allow staged or variable operation, such that individual fans 402 may operate at different speeds or may be selectively energized depending on load conditions, as described below. This configuration may also provide operational redundancy, as airflow may continue even if one fan 402 is offline for maintenance.

[0038] In the configuration illustrated in FIG. 4, each fan 402 of intermediate fan module 206 may be aligned with a corresponding fan of discharge fan section 208. For example, the axis of rotation of a fan 402 may be substantially aligned with an axis of rotation of a corresponding fan of section 208. In this embodiment and each embodiment disclosed herein, fans 208 and 402 may rotate in the same direction, or in different directions. Further, fans 208 and 402 may be the same type of fan (e.g., axial, centrifugal, etc.) or may be different fan types.

[0039] Exemplary assembly 500 in FIG. 5 illustrates another embodiment in which the intermediate fan module 206 includes multiple rows of fans, represented by first fan row 502a and second fan row 502b, arranged in a two dimensional array within the plenum 210 of the assembly 200. In this configuration, the first fan row 502a and second fan row 502b may be arranged in both longitudinal and transverse directions relative to the assembly 200, thereby covering a larger portion of the cross sectional area between the upper heat exchange module 202 and the lower heat exchange module 204. The multi-row configuration may promote uniform airflow distribution across the face areas of the modules 202 and 204. It may also permit finer airflow control, as first fan row 502a and second fan row 502b may be independently controlled (e.g., by controller 901, also referred to herein as a “control system”; FIG. 9) to address localized thermal loads or to compensate for airflow imbalances. As shown in FIG. 5, fans of rows 502a and 502b form groups of four fans that all overlap a single corresponding fan of section 208, forming a 4:1 ratio of intermediate fans to exhaust fans. Other exemplary ratios include 1:3 (FIG. 3), 1:4, 1:1 (FIG. 4), 2:1, 3:1, 4:1 (FIG. 5), 6:1, 8:1, etc.

[0040] Although FIGS. 3-5 illustrate specific example configurations of the intermediate fan module 206 positioned within the plenum 210, these arrangements are representative and not limiting. Other combinations of fan diameters, quantities, and layouts may be implemented within the intermediate fan module 206 while remaining within the scope of the concepts described herein.

[0041] Additionally, although the foregoing portions of the application indicate that the intermediate fan module 206 may be positioned between the upper and lower heat exchange modules 202, 204, such positioning is not intended to be limiting. In certain implementations, the intermediate fan module 206 need not be located physically “intermediate” the upper and lower heat exchange modules 202, 204, and may instead be positioned at locations within the assembly consistent with the concepts further described herein in which the intermediate fan module is fluidly connected between an air inlet and a downstream fan section.

[0042] For example, exemplary assembly 600 in FIG. 6 illustrates an arrangement in which one or more fan modules 602 are integrated within a heat exchanger module rather than being provided as a discrete module positioned physically between vertically adjacent heat exchange modules. In this configuration, the fan modules 602 may be entirely or at least partially contained within the structural envelope of the heat exchange module, such that airflow energy may be introduced within the module itself as air passes through associated heat exchange coil 150. As a result, the fan modules 602 may function in a manner similar to the intermediate fan module described above, while being incorporated into either an upper or lower heat exchange module rather than being located in a separate plenum between modules. This arrangement may reduce overall assembly height while still providing improved airflow distribution throughout the assembly 600.

[0043] As another example, exemplary assembly 700 in FIG. 7 illustrates an arrangement in which airflow assistance is provided by one or more fan modules 702 that are not oriented horizontally(e.g., with a vertically-extending axis of rotation about which blades of the fan move during operation), but instead, are associated with inward-facing surfaces of heat exchange coils 150, with the one or more fan modules 702 being oriented at an angle relative to horizontal and vertical directions. For example, the one or more fan modules 702 may be inclined so as to face inward and upward with inclined axes of rotation (e.g., axes of rotation that are orthogonal to a plane defined by a heat exchange panel or coil section), such that each fan module 702 draws air from within the interior region adjacent the lower heat exchange coils 150 and discharges the air along a generally upward flow path toward upper heat exchange coils 152 and a discharge fan section 105. In this configuration, the one or more fan modules 702 may be entirely or at least partially contained within the interior space defined by the coils 150.

[0044] The one or more fan modules 702 may be associated with cowling, ducting, or other flow-directing structures configured to receive air passing through the lower heat exchange coils 150 and to redirect the air in an upward direction toward the upper heat exchange coils 152 and the discharge fan section 105. This configuration may take advantage of the available space between the lower and upper heat exchange coils 150, 152 and may improve airflow distribution without requiring a dedicated intermediate module positioned between vertically stacked heat exchange modules.

[0045] Additionally or alternatively, exemplary assembly 800 in FIG. 8 illustrates a multi-level, vertically stacked heat exchange configuration in which a plurality of heat exchange modules 804, 806, and 808 are arranged one above another beneath a discharge fan section 105. In this embodiment, the assembly 800 may include three vertically stacked heat exchange modules 804806, 808 (e.g., forming a “triple stack” of heat exchange modules), thereby increasing available heat transfer surface area within a given footprint. One or more intermediate airflow modules 802 may be positioned at one or more vertical locations within the assembly 800, such as between adjacent heat exchange modules 804, 806, 808 (e.g., FIG. 8 illustrates that an intermediate airflow module 802 is positioned between heat exchange modules 804 and 806; an additional intermediate airflow module 802 may be positioned between modules 804 and 806) or within one or more of the modules 804, 806, 808 themselves. The intermediate airflow module(s) 802 may be configured to introduce additional airflow energy at intermediate elevations within the assembly 800, thereby assisting movement of air through lower portions of the assembly, including the lowest heat exchange module 808, and directing the air upward toward the upper module 806, 804 and ultimately to the discharge fan section 105. In an embodiment, as the number of vertically stacked modules increases, airflow resistance and potential airflow reduction at lower levels may become more pronounced. Accordingly, the incorporation of one or more intermediate airflow modules 802 within the assembly 800 may mitigate reduced airflow to the lower exchange module 808, improve airflow distribution across all modules 804, 806, 808, and enhance overall performance and efficiency of the assembly 800.

[0046] In an embodiment, the discharge fan section 208 may be positioned above the upper heat exchange module 202 and may include one or more discharge fans configured to exhaust air from the assembly 200 to atmosphere. The discharge fan section 208 and the intermediate fan module 206 may be operated independently or cooperatively to provide a staged airflow system in which airflow energy is introduced at multiple vertical locations within the assembly 200. By selectively operating the intermediate fan module 206 and the discharge fan section 208, the assembly 200 may accommodate varying thermal loads, ambient conditions, and system operating requirements.

[0047] In certain operating conditions, the discharge fan section 208 alone may provide sufficient airflow through the lower heat exchange module 204 and the upper heat exchange module 202. For example, during periods of low ambient temperature or reduced heat load, operation of only the discharge fan section 208 may maintain desired heat rejection capacity while reducing overall power consumption. In this mode, the intermediate fan module 206 may be deactivated or operated at a reduced speed.

[0048] In other operating conditions, the intermediate fan module 206 may operate independently of the discharge fan section 208 (e.g., in a first operating mode where intermediate fan section 206 is controlled according to signals from sensor(s) 902, described below) or the discharge fan section 208 may operate independently of intermediate fan module 206 (e.g., in a second operating mode where discharge fan section 208 is controlled according to sensor(s) 902). A third operating mode may involve operating both the intermediate fan module 206 and the discharge fan section 208 simultaneously (e.g., by controller 901 and discharge fan section 208 based on signals from sensor(s) 902).

[0049] In some configurations, the intermediate fan module 206 may be activated to increase airflow through the lower heat exchange module 204 while the discharge fan section 208 operates at reduced speed or even without being supplied with power. In some embodiments, the intermediate fan module 206 may provide sufficient airflow to move air through both the lower heat exchange module 204 and the upper heat exchange module 202, allowing the discharge fan section 208 to be powered at a reduced level, remain off, or to operate intermittently.

[0050] In higher load or higher ambient temperature conditions, the intermediate fan module 206 and the discharge fan section 208 may operate simultaneously. When operating simultaneously, the intermediate fan module 206 and the discharge fan section 208 may be driven by controller 901 to operate at the same rotational speed or at different speeds. For example, the intermediate fan module 206 may operate at a higher speed to overcome static pressure across the lower heat exchange module 204, while the discharge fan section 208 may operate at a lower speed sufficient to exhaust air from the upper heat exchange module 202. In other situations, both fan sections may operate at elevated speeds to maximize total airflow through the assembly 200.

[0051] The rotational speeds of the intermediate fan module 206 and the discharge fan section 208 may be adjusted or controlled with controller 901 using variable frequency drives, electronically commutated motors, or other adjustable motor control systems. Independent speed control may allow the airflow profile through the lower heat exchange module 204 and the upper heat exchange module 202 to be tuned with controller 901 for improved uniformity and efficiency. By distributing the airflow work between the intermediate fan module 206 and the discharge fan section 208, overall system efficiency may be improved relative to a configuration relying solely on the discharge fan section 208.

[0052] As shown in FIG. 9, the assembly 900 may include a control system (e.g., controller 901) configured to dynamically determine when to activate or deactivate the intermediate fan module 206 and the discharge fan section 208. The controller 901 may be configured to receive input signals from one or more sensors 902. Sensors 902 may include, for example, ambient air temperature sensors, fluid supply temperature sensors, fluid return temperature sensors, fluid pressure sensors, airflow sensors, motor current sensors, or pressure sensors configured to detect differential pressure across the heat exchange modules 202 or 204. Based on these inputs, controller 901 may adjust fan operation to maintain desired fluid outlet temperature, condensing temperature, or approach temperature. For example, sensors 902 may output a signal that indicates at least one operating condition that the control system uses to selectively operate intermediate fan module 206, independent of, or in conjunction with, discharge fan section 208.

[0053] For example, if differential pressure detected with sensor 902 across the lower heat exchange module 204 exceeds a threshold value or if airflow through the lower heat exchange module 204 falls below a target level, the control system may activate or increase the speed of the intermediate fan module 206. Conversely, if ambient conditions allow sufficient heat rejection with reduced airflow, controller 901 may reduce speed or deactivate the intermediate fan module 206 while maintaining operation of the discharge fan section 208. In certain embodiments, staged control logic may sequentially energize fans within the intermediate fan module 206 and within the discharge fan section 208 as load increases, thereby providing incremental airflow increases.

[0054] The staged airflow system formed by the intermediate fan module 206 and the discharge fan section 208 may therefore provide flexible operating modes, including discharge-fan-only operation, intermediate-fan-only operation, and combined operation during which both discharge fans and intermediate fan(s) are operated. This flexibility may allow the assembly 900 to adapt to varying environmental and load conditions while balancing heat rejection performance, sound levels, and energy consumption.

[0055] FIG. 9 also illustrates a representative airflow condition of the assembly 900 when both the intermediate fan module 206 and the discharge fan section 208 are operating in response to commands from controller 901. In this operating mode, air may move through the assembly 900 in a staged manner, with airflow energy being added at vertically separated locations. Airflow lines 282 represent air drawn upward from a lower region of the assembly 900, and airflow lines 280 represent air drawn into the discharge fan section 208 from an upper region of the assembly 900.

[0056] Ambient air may first enter the assembly 900 through exterior lateral surfaces of the lower heat exchange module 204. The air may pass laterally through the heat transfer surfaces, for example through coils 250, of the lower heat exchange module 204 and enter the plenum 210 located between the lower heat exchange module 204 and the upper heat exchange module 202. The intermediate fan module 206 may draw this air from the plenum 210 and increase the velocity and pressure of air, thereby directing the air upward toward the upper heat exchange module 202. The upwardly moving air is illustrated schematically by airflow lines 282 originating from the lower portion of the assembly 900.

[0057] After leaving the intermediate fan module 206, the air may pass through the upper heat exchange module 202. The discharge fan section 208 may then draw the air upward and exhaust the air to atmosphere. Air drawn toward the discharge fan section 208 from the upper region of the assembly 900 is schematically illustrated by airflow lines 280.

[0058] The concepts described herein relate to the placement of one or more fan assemblies at an intermediate elevation between stacked heat exchanger coil sections. Rather than relying solely on a single induced draft region at the top of the unit, an additional airflow driving stage may be positioned between vertically adjacent coil modules. The disclosed system and method may draw air through a lower coil section and then discharge that air toward an upper coil section, thereby establishing staged airflow through the stacked assembly. By introducing airflow energy at an intermediate location, the airflow resistance experienced by the lower coil section may be reduced and airflow distribution across the height of the unit may become more balanced. The lower coil surfaces may receive greater airflow while the upper coil surfaces may receive airflow that is more uniform across their area. As a result, a greater portion of the available heat transfer surface area may contribute effectively to heat rejection.

[0059] These concepts may provide improved airflow distribution and higher effective capacity within a given footprint and height envelope while reducing the need for additional heat exchange units. The approach may also allow fan speed and power requirements to be moderated relative to configurations that rely solely on top mounted fans. Optional adiabatic assist components, such as wetted media (e.g., adiabatic pads) or spray systems, may be incorporated to further enhance heat rejection while still using relatively small amounts of water.

[0060] It should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

[0061] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0062] Thus, while certain embodiments have been described, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as falling within the scope of the invention. For example, functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[0063] The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other implementations, which fall within the true spirit and scope of the present disclosure. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description. While various implementations of the disclosure have been described, it will be apparent to those of ordinary skill in the art that many more implementations are possible within the scope of the disclosure. Accordingly, the disclosure is not to be restricted except in light of the attached claims and their equivalents.

Examples

Embodiment Construction

[0021]The terminology used below may be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the present disclosure. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.

[0022]In this disclosure, the term “based on” means “based at least in part on.” The singular forms “a,”“an,” and “the” include plural referents unless the context dictates otherwise. The term “exemplary” is used in the sense of “example” rather than “ideal.” The terms “comprises,”“comprising,”“includes,”“including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article or apparatus that comprises a list of elements does not necessarily include only those elements, and may include other elements not ex...

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 774,436, filed on Mar. 19, 2025, which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] Aspects of the present disclosure relate generally to air-cooled heat exchangers used in refrigeration or cooling, or in heating, ventilation, and air conditioning (HVAC). More particularly, the present disclosure relates to multi-level air-cooled heat exchangers incorporating one or more intermediate fan modules.BACKGROUND

[0003] Air-cooled heat exchangers are used in refrigeration, industrial cooling, and HVAC systems. High heat loads, for example in data center environments, together with water use restrictions, have increased reliance on air cooled heat rejection systems. Some of these systems include heat exchange units with tube and fin coils as well as fans located at the top of the unit to draw air upward. To increase capacity within a limited footprint, manufacturers have introduced vertically stacked coil sections. In some arrangements of these stacked heat exchange systems, a single top fan section pulls air through all levels. While useful, these systems can benefit from greater airflow and / or control over airflow.

[0004] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art, or suggestions of the prior art, by inclusion in this section. Further, the scope of the disclosure is defined by the attached claims and not by the ability to solve a particular problem, includes the problems described above.SUMMARY OF THE DISCLOSURE

[0005] According to certain aspects of the disclosure, one or more fan assemblies may be positioned between vertically stacked heat exchanger coil modules to assist movement of air through the stacked sections and to improve airflow distribution across the heat exchanger.

[0006] In one aspect, an air cooled heat exchange assembly is provided. The air cooled heat exchange assembly may include: a first heat exchange module configured to receive air and to transfer heat from a working fluid to the air; a second heat exchange module positioned adjacent to the first heat exchange module, the second heat exchange module being configured to receive air and to transfer heat from the working fluid to the air; a first fan module positioned adjacent to the second heat exchange module; and a second fan module positioned between the first heat exchange module and the second heat exchange module, the second fan module being configured to draw air through the first heat exchange module and to discharge the air toward the first fan module.

[0007] In another aspect, a method of using a heat exchange assembly is provided. The heat exchange assembly may include a first heat exchange module, a second heat exchange module positioned adjacent to the first heat exchange module, a second fan module positioned between the first heat exchange module and the second heat exchange module, and a first fan module positioned adjacent to the second heat exchange module, and the method may include: drawing ambient air through the first heat exchange module to transfer heat from a working fluid to the ambient air; operating the second fan module to draw air that has passed through the first heat exchange module and to add airflow energy between the first heat exchange module and the second heat exchange module; and operating the first fan module to draw air through the second heat exchange module and to exhaust the air from the heat exchange assembly.

[0008] In yet another aspect, an air cooled heat exchange assembly is provided. The air cooled heat exchange assembly may include: at least two heat exchange modules arranged such that air passes sequentially through the at least two heat exchange modules, each heat exchange module including at least one heat exchange coil configured to transfer heat from a working fluid to the air; a first airflow module positioned to move air through the at least two heat exchange modules; and at least one additional airflow module including one or more fans configured to: (i) draw air that has passed through at least one of the at least two heat exchange modules, and (ii) discharge the air toward another of the at least two heat exchange modules, wherein the at least one additional airflow module is positioned at a location within the air cooled heat exchange assembly selected from: (i) between adjacent heat exchange modules of the at least two exchange modules, and (ii) within at least one heat exchange module of the at least two heat exchange modules.

[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the disclosed embodiments, and, together with the description, serve to explain the principles of the disclosed embodiments. There are many aspects and embodiments described herein.

[0011] FIG. 1A depicts an isometric view of an exemplary air cooled heat exchanger unit.

[0012] FIG. 1B depicts a front view of a vertically stacked air cooled heat exchanger unit.

[0013] FIG. 2 depicts a front view of an air cooled heat exchange assembly including an intermediate fan module, according to one or more aspects of the present disclosure.

[0014] FIG. 3 depicts an exploded view of the air cooled heat exchange assembly illustrating an embodiment in which the intermediate fan module includes a single large diameter fan positioned between vertically stacked heat exchange modules, according to one or more embodiments of the present disclosure.

[0015] FIG. 4 depicts an exploded view of the air cooled heat exchange assembly illustrating an embodiment in which the intermediate fan module includes a plurality of fans arranged in a single row between vertically stacked heat exchange modules, according to one or more embodiments of the present disclosure.

[0016] FIG. 5 depicts an exploded view of the air cooled heat exchange assembly illustrating an embodiment in which the intermediate fan module includes a plurality of fans arranged in rows between vertically stacked heat exchange modules, according to one or more embodiments of the present disclosure.

[0017] FIG. 6 depicts an embodiment in which one or more fan modules are integrated within a heat exchange module, according to one or more embodiments of the present disclosure.

[0018] FIG. 7 depicts an embodiment in which one or more fan modules are oriented at an angle along inward-facing surfaces of heat exchange coils, according to one or more embodiments of the present disclosure.

[0019] FIG. 8 depicts an embodiment of an air cooled heat exchange assembly having a plurality of vertically stacked heat exchange modules and one or more intermediate airflow modules positioned at one or more elevations within the assembly, according to one or more embodiments of the present disclosure.

[0020] FIG. 9 depicts a front view of the air cooled heat exchange assembly illustrating airflow when both the intermediate fan module and the discharge fan section are operating, according to one or more embodiments of the present disclosure.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The terminology used below may be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the present disclosure. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.

[0022] In this disclosure, the term “based on” means “based at least in part on.” The singular forms “a,”“an,” and “the” include plural referents unless the context dictates otherwise. The term “exemplary” is used in the sense of “example” rather than “ideal.” The terms “comprises,”“comprising,”“includes,”“including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article or apparatus that comprises a list of elements does not necessarily include only those elements, and may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. Relative terms, such as “about,”“approximately,”“substantially,” and “generally,” are used to indicate a possible variation of ±10% of a stated or understood value. In addition, the term “between” used in describing ranges of values is intended to include the minimum and maximum values described in that range. The use of the term “or” in the claims and specification is used to mean “and / or” unless either explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and / or.” As used herein “another” may mean at least a second or more.

[0023] As used herein, the term “fan” refers to any air moving device configured to impart motion to air, including but not limited to axial fans, centrifugal fans, mixed flow fans, plug fans, blower wheels, or similar air moving mechanisms, and may be driven by electric motors, electronically commutated motors, belt driven arrangements, direct drive arrangements, or other drive systems. The term “heat exchanger coil” may refer to any fluid to air heat transfer structure, including tube and fin coils, microchannel coils, plate fin coils, or other extended surface heat transfer assemblies carrying refrigerant, water, glycol solutions, dielectric fluids, or other working fluids. The term “module” may refer to a structural section or portion of a heat exchange assembly that may be manufactured, transported, or installed as a unit and that may include one or more coils, fans, plenums, housings, or support members. Relative positional terms such as “top,”“bottom,”“upper,”“lower,” and “intermediate” are used for convenience of description with reference to example orientations and are not intended to limit the orientation of the equipment during manufacture, transport, or operation.

[0024] Vertically stacked air cooled heat exchangers may include multiple coil sections arranged one above another within a single structural envelope. Double and triple stacked configurations are examples of this approach. Each level of the system may include a separate heat exchange module or fan module, with each heat exchange module including one or a plurality of heat exchange coil sections, or panels.

[0025] FIGS. 1A and 1B show an exemplary configuration of a double stack (e.g., two unitary and separately shippable modules) heat exchange system including upper and lower heat exchange modules that are connected to each other to form a single heat exchange system. These systems may include a fan section located at the top of the unit that pulls air through all stacked coil sections simultaneously. The fan section may be integral and unitary with upper heat exchange module. The increased coil surface area, in comparison with single-level heat exchange systems, may increase thermal capacity and performance.

[0026] As shown in FIGS. 1A and 1B, an air cooled heat exchange assembly 100 may be provided with an upper fan module (also referring to herein as a “discharge fan section”) 105 and a lower or intermediate fan module 206. Intermediate fan module 206 may be located at about a center-point between a lower module with a lower heat exchange coil 150 and an upper module with an upper heat exchange coil 152. While intermediate fan module 206 is shown in an exemplary location between coils 150 and 152, optional module locations 205 and 207 are shown in FIG. 1B.

[0027] Module location 205 for intermediate fan module 206 may partially or entirely overlap lower heat exchange coil 150 or may otherwise position an entirety or a portion of intermediate fan module 206 within the lower module. Location 207 for intermediate fan module 206 may partially or entirely overlap upper heat exchange coil 152 of the upper module. Location 207 or 205 may be utilized to reduce the overall height of heat exchange assembly 100.

[0028] FIG. 2 illustrates an air cooled heat exchange assembly 200 (“assembly”) with multiple heat exchange modules that are stacked to be vertically adjacent to each other. The assembly 200 may include an upper heat exchange module 202 (e.g., a “first” heat exchange module) positioned above a lower heat exchange module 204 (e.g., an “intermediate” or “second” heat exchange module). An intermediate fan module 206 (e.g., a “second” fan module) may be located between the upper heat exchange module 202 and the lower heat exchange module 204. A discharge fan section 208 (e.g., a “first” fan module) may be positioned at an upper portion of the assembly 200.

[0029] The lower heat exchange module 204 may include one or more fluid to air heat exchanger coils 250 arranged to receive ambient air through exterior coil surfaces. The upper heat exchange module 202 may similarly include one or more heat exchanger coils 252. The coils 250, 252 of the modules 202 and 204 may be tube and fin coils, microchannel coils, or other extended surface heat transfer structures configured to transfer heat from a circulating working fluid to air. The modules 202 and 204 may be supported by a structural frame and may be vertically aligned so that air passing through the lower heat exchange module 204 may subsequently pass through the upper heat exchange module 202.

[0030] The intermediate fan module 206 may be positioned within a plenum 210 between the modules 202 and 204. The plenum 210 may extend substantially across an entire width of the assembly 200 and may define an airflow chamber through which air exiting the lower heat exchange module 204 passes prior to entering the upper heat exchange module 202. The intermediate fan module 206 may be at least partially enclosed by housing panels, shrouds, or other types of structural members so that air moved by the intermediate fan module 206 is primarily drawn from air exiting the lower heat exchange module 204 rather than directly from ambient surroundings. In operation, the intermediate fan module 206 may pull air through the lower heat exchange module 204 and discharge the air toward the upper heat exchange module 202, as further illustrated and described herein.

[0031] The intermediate fan module 206 may include one or more fans. The intermediate fan module 206 may include one or more axial fans. In other embodiments, the intermediate fan module 206 may include centrifugal fans, plug fans, mixed flow fans, blower wheels, or combinations thereof. The fans of the intermediate fan module 206 may be driven by electric motors including direct drive motors, belt driven motors, electronically commutated motors, or other suitable motor arrangements.

[0032] The intermediate fan module 206 may be mounted directly to frame members separating the modules 202 and 204 (e.g., in a separate housing that extends from module 202 to module 204) or may be supported by a dedicated fan deck or panel. In other configurations, intermediate fan module 206 is integrated within module 202 or module 204 (e.g., as described with respect to locations 205 and 207 in FIG. 1B). The intermediate fan module 206 may be positioned approximately at a center point in a vertical direction between the modules 202 and 204, although other vertical placements may be used. For example, the intermediate fan module 206 may be positioned closer to the lower heat exchange module 204 to increase airflow through the lower module, or closer to the upper heat exchange module 202 to adjust airflow distribution depending on operating conditions.

[0033] The housing that contains fans of intermediate fan module 206 may partially or entirely surround the fans of module 206. In one example, all four sides of intermediate fan module 206 may be enclosed by a housing such that an entirety of the air received by heat exchange modules 250 and 252 passes through the corresponding heat exchange coils. In other aspects, one, two, three, or four sides of the housing for intermediate fan module 206 may be open or at least partially open. For example, in the illustrated configuration, a pair of laterally-opposite side walls are formed on opposite sides of the fans of intermediate fan module 206, with an opening being formed between the side walls.

[0034] The intermediate fan module 206 may include inlet bellmouths, venturi rings, or shrouds configured to guide air into the fan. Downstream of the fans, diffusers, turning vanes, or flow straighteners may be provided to direct airflow toward the upper heat exchange module 202. Such airflow management components may reduce recirculation and may improve uniform airflow distribution across the coil surfaces of the upper heat exchange module 202.

[0035] The intermediate fan module 206 may be arranged in a variety of configurations within the assembly 200, as illustrated in the exploded views of FIGS. 3-5. Different fan configurations may be selected based on desired airflow volume, static pressure capability, redundancy, serviceability, or manufacturing considerations, for example.

[0036] As shown in exemplary assembly 300 in FIG. 3, the intermediate fan module 206 may include a single large diameter fan 302 positioned centrally, in length and width directions, within the plenum 210 between the upper heat exchange module 202 and the lower heat exchange module 204. The single large diameter fan 302 may extend across a portion or an entirety of the plan area between the modules 202 and 204. In this configuration, the single large diameter fan 302 may provide relatively high airflow at moderate static pressure while minimizing the number of rotating components. The use of a single large diameter fan 302 may simplify controls and electrical connections and may reduce the number of service points associated with the intermediate fan module 206.

[0037] As illustrated in exemplary assembly 400 in FIG. 4, the intermediate fan module 206 may alternatively include a plurality of fans 402 arranged in a single row extending across the width of the plenum 210. The fans 402 may be positioned side by side in a front-to-rear direction of the assembly 200 so that each fan 402 moves air through a corresponding portion of the lower heat exchange module 204 and into a corresponding portion of the upper heat exchange module 202. The use of multiple smaller fans 402 may allow staged or variable operation, such that individual fans 402 may operate at different speeds or may be selectively energized depending on load conditions, as described below. This configuration may also provide operational redundancy, as airflow may continue even if one fan 402 is offline for maintenance.

[0038] In the configuration illustrated in FIG. 4, each fan 402 of intermediate fan module 206 may be aligned with a corresponding fan of discharge fan section 208. For example, the axis of rotation of a fan 402 may be substantially aligned with an axis of rotation of a corresponding fan of section 208. In this embodiment and each embodiment disclosed herein, fans 208 and 402 may rotate in the same direction, or in different directions. Further, fans 208 and 402 may be the same type of fan (e.g., axial, centrifugal, etc.) or may be different fan types.

[0039] Exemplary assembly 500 in FIG. 5 illustrates another embodiment in which the intermediate fan module 206 includes multiple rows of fans, represented by first fan row 502a and second fan row 502b, arranged in a two dimensional array within the plenum 210 of the assembly 200. In this configuration, the first fan row 502a and second fan row 502b may be arranged in both longitudinal and transverse directions relative to the assembly 200, thereby covering a larger portion of the cross sectional area between the upper heat exchange module 202 and the lower heat exchange module 204. The multi-row configuration may promote uniform airflow distribution across the face areas of the modules 202 and 204. It may also permit finer airflow control, as first fan row 502a and second fan row 502b may be independently controlled (e.g., by controller 901, also referred to herein as a “control system”; FIG. 9) to address localized thermal loads or to compensate for airflow imbalances. As shown in FIG. 5, fans of rows 502a and 502b form groups of four fans that all overlap a single corresponding fan of section 208, forming a 4:1 ratio of intermediate fans to exhaust fans. Other exemplary ratios include 1:3 (FIG. 3), 1:4, 1:1 (FIG. 4), 2:1, 3:1, 4:1 (FIG. 5), 6:1, 8:1, etc.

[0040] Although FIGS. 3-5 illustrate specific example configurations of the intermediate fan module 206 positioned within the plenum 210, these arrangements are representative and not limiting. Other combinations of fan diameters, quantities, and layouts may be implemented within the intermediate fan module 206 while remaining within the scope of the concepts described herein.

[0041] Additionally, although the foregoing portions of the application indicate that the intermediate fan module 206 may be positioned between the upper and lower heat exchange modules 202, 204, such positioning is not intended to be limiting. In certain implementations, the intermediate fan module 206 need not be located physically “intermediate” the upper and lower heat exchange modules 202, 204, and may instead be positioned at locations within the assembly consistent with the concepts further described herein in which the intermediate fan module is fluidly connected between an air inlet and a downstream fan section.

[0042] For example, exemplary assembly 600 in FIG. 6 illustrates an arrangement in which one or more fan modules 602 are integrated within a heat exchanger module rather than being provided as a discrete module positioned physically between vertically adjacent heat exchange modules. In this configuration, the fan modules 602 may be entirely or at least partially contained within the structural envelope of the heat exchange module, such that airflow energy may be introduced within the module itself as air passes through associated heat exchange coil 150. As a result, the fan modules 602 may function in a manner similar to the intermediate fan module described above, while being incorporated into either an upper or lower heat exchange module rather than being located in a separate plenum between modules. This arrangement may reduce overall assembly height while still providing improved airflow distribution throughout the assembly 600.

[0043] As another example, exemplary assembly 700 in FIG. 7 illustrates an arrangement in which airflow assistance is provided by one or more fan modules 702 that are not oriented horizontally(e.g., with a vertically-extending axis of rotation about which blades of the fan move during operation), but instead, are associated with inward-facing surfaces of heat exchange coils 150, with the one or more fan modules 702 being oriented at an angle relative to horizontal and vertical directions. For example, the one or more fan modules 702 may be inclined so as to face inward and upward with inclined axes of rotation (e.g., axes of rotation that are orthogonal to a plane defined by a heat exchange panel or coil section), such that each fan module 702 draws air from within the interior region adjacent the lower heat exchange coils 150 and discharges the air along a generally upward flow path toward upper heat exchange coils 152 and a discharge fan section 105. In this configuration, the one or more fan modules 702 may be entirely or at least partially contained within the interior space defined by the coils 150.

[0044] The one or more fan modules 702 may be associated with cowling, ducting, or other flow-directing structures configured to receive air passing through the lower heat exchange coils 150 and to redirect the air in an upward direction toward the upper heat exchange coils 152 and the discharge fan section 105. This configuration may take advantage of the available space between the lower and upper heat exchange coils 150, 152 and may improve airflow distribution without requiring a dedicated intermediate module positioned between vertically stacked heat exchange modules.

[0045] Additionally or alternatively, exemplary assembly 800 in FIG. 8 illustrates a multi-level, vertically stacked heat exchange configuration in which a plurality of heat exchange modules 804, 806, and 808 are arranged one above another beneath a discharge fan section 105. In this embodiment, the assembly 800 may include three vertically stacked heat exchange modules 804806, 808 (e.g., forming a “triple stack” of heat exchange modules), thereby increasing available heat transfer surface area within a given footprint. One or more intermediate airflow modules 802 may be positioned at one or more vertical locations within the assembly 800, such as between adjacent heat exchange modules 804, 806, 808 (e.g., FIG. 8 illustrates that an intermediate airflow module 802 is positioned between heat exchange modules 804 and 806; an additional intermediate airflow module 802 may be positioned between modules 804 and 806) or within one or more of the modules 804, 806, 808 themselves. The intermediate airflow module(s) 802 may be configured to introduce additional airflow energy at intermediate elevations within the assembly 800, thereby assisting movement of air through lower portions of the assembly, including the lowest heat exchange module 808, and directing the air upward toward the upper module 806, 804 and ultimately to the discharge fan section 105. In an embodiment, as the number of vertically stacked modules increases, airflow resistance and potential airflow reduction at lower levels may become more pronounced. Accordingly, the incorporation of one or more intermediate airflow modules 802 within the assembly 800 may mitigate reduced airflow to the lower exchange module 808, improve airflow distribution across all modules 804, 806, 808, and enhance overall performance and efficiency of the assembly 800.

[0046] In an embodiment, the discharge fan section 208 may be positioned above the upper heat exchange module 202 and may include one or more discharge fans configured to exhaust air from the assembly 200 to atmosphere. The discharge fan section 208 and the intermediate fan module 206 may be operated independently or cooperatively to provide a staged airflow system in which airflow energy is introduced at multiple vertical locations within the assembly 200. By selectively operating the intermediate fan module 206 and the discharge fan section 208, the assembly 200 may accommodate varying thermal loads, ambient conditions, and system operating requirements.

[0047] In certain operating conditions, the discharge fan section 208 alone may provide sufficient airflow through the lower heat exchange module 204 and the upper heat exchange module 202. For example, during periods of low ambient temperature or reduced heat load, operation of only the discharge fan section 208 may maintain desired heat rejection capacity while reducing overall power consumption. In this mode, the intermediate fan module 206 may be deactivated or operated at a reduced speed.

[0048] In other operating conditions, the intermediate fan module 206 may operate independently of the discharge fan section 208 (e.g., in a first operating mode where intermediate fan section 206 is controlled according to signals from sensor(s) 902, described below) or the discharge fan section 208 may operate independently of intermediate fan module 206 (e.g., in a second operating mode where discharge fan section 208 is controlled according to sensor(s) 902). A third operating mode may involve operating both the intermediate fan module 206 and the discharge fan section 208 simultaneously (e.g., by controller 901 and discharge fan section 208 based on signals from sensor(s) 902).

[0049] In some configurations, the intermediate fan module 206 may be activated to increase airflow through the lower heat exchange module 204 while the discharge fan section 208 operates at reduced speed or even without being supplied with power. In some embodiments, the intermediate fan module 206 may provide sufficient airflow to move air through both the lower heat exchange module 204 and the upper heat exchange module 202, allowing the discharge fan section 208 to be powered at a reduced level, remain off, or to operate intermittently.

[0050] In higher load or higher ambient temperature conditions, the intermediate fan module 206 and the discharge fan section 208 may operate simultaneously. When operating simultaneously, the intermediate fan module 206 and the discharge fan section 208 may be driven by controller 901 to operate at the same rotational speed or at different speeds. For example, the intermediate fan module 206 may operate at a higher speed to overcome static pressure across the lower heat exchange module 204, while the discharge fan section 208 may operate at a lower speed sufficient to exhaust air from the upper heat exchange module 202. In other situations, both fan sections may operate at elevated speeds to maximize total airflow through the assembly 200.

[0051] The rotational speeds of the intermediate fan module 206 and the discharge fan section 208 may be adjusted or controlled with controller 901 using variable frequency drives, electronically commutated motors, or other adjustable motor control systems. Independent speed control may allow the airflow profile through the lower heat exchange module 204 and the upper heat exchange module 202 to be tuned with controller 901 for improved uniformity and efficiency. By distributing the airflow work between the intermediate fan module 206 and the discharge fan section 208, overall system efficiency may be improved relative to a configuration relying solely on the discharge fan section 208.

[0052] As shown in FIG. 9, the assembly 900 may include a control system (e.g., controller 901) configured to dynamically determine when to activate or deactivate the intermediate fan module 206 and the discharge fan section 208. The controller 901 may be configured to receive input signals from one or more sensors 902. Sensors 902 may include, for example, ambient air temperature sensors, fluid supply temperature sensors, fluid return temperature sensors, fluid pressure sensors, airflow sensors, motor current sensors, or pressure sensors configured to detect differential pressure across the heat exchange modules 202 or 204. Based on these inputs, controller 901 may adjust fan operation to maintain desired fluid outlet temperature, condensing temperature, or approach temperature. For example, sensors 902 may output a signal that indicates at least one operating condition that the control system uses to selectively operate intermediate fan module 206, independent of, or in conjunction with, discharge fan section 208.

[0053] For example, if differential pressure detected with sensor 902 across the lower heat exchange module 204 exceeds a threshold value or if airflow through the lower heat exchange module 204 falls below a target level, the control system may activate or increase the speed of the intermediate fan module 206. Conversely, if ambient conditions allow sufficient heat rejection with reduced airflow, controller 901 may reduce speed or deactivate the intermediate fan module 206 while maintaining operation of the discharge fan section 208. In certain embodiments, staged control logic may sequentially energize fans within the intermediate fan module 206 and within the discharge fan section 208 as load increases, thereby providing incremental airflow increases.

[0054] The staged airflow system formed by the intermediate fan module 206 and the discharge fan section 208 may therefore provide flexible operating modes, including discharge-fan-only operation, intermediate-fan-only operation, and combined operation during which both discharge fans and intermediate fan(s) are operated. This flexibility may allow the assembly 900 to adapt to varying environmental and load conditions while balancing heat rejection performance, sound levels, and energy consumption.

[0055] FIG. 9 also illustrates a representative airflow condition of the assembly 900 when both the intermediate fan module 206 and the discharge fan section 208 are operating in response to commands from controller 901. In this operating mode, air may move through the assembly 900 in a staged manner, with airflow energy being added at vertically separated locations. Airflow lines 282 represent air drawn upward from a lower region of the assembly 900, and airflow lines 280 represent air drawn into the discharge fan section 208 from an upper region of the assembly 900.

[0056] Ambient air may first enter the assembly 900 through exterior lateral surfaces of the lower heat exchange module 204. The air may pass laterally through the heat transfer surfaces, for example through coils 250, of the lower heat exchange module 204 and enter the plenum 210 located between the lower heat exchange module 204 and the upper heat exchange module 202. The intermediate fan module 206 may draw this air from the plenum 210 and increase the velocity and pressure of air, thereby directing the air upward toward the upper heat exchange module 202. The upwardly moving air is illustrated schematically by airflow lines 282 originating from the lower portion of the assembly 900.

[0057] After leaving the intermediate fan module 206, the air may pass through the upper heat exchange module 202. The discharge fan section 208 may then draw the air upward and exhaust the air to atmosphere. Air drawn toward the discharge fan section 208 from the upper region of the assembly 900 is schematically illustrated by airflow lines 280.

[0058] The concepts described herein relate to the placement of one or more fan assemblies at an intermediate elevation between stacked heat exchanger coil sections. Rather than relying solely on a single induced draft region at the top of the unit, an additional airflow driving stage may be positioned between vertically adjacent coil modules. The disclosed system and method may draw air through a lower coil section and then discharge that air toward an upper coil section, thereby establishing staged airflow through the stacked assembly. By introducing airflow energy at an intermediate location, the airflow resistance experienced by the lower coil section may be reduced and airflow distribution across the height of the unit may become more balanced. The lower coil surfaces may receive greater airflow while the upper coil surfaces may receive airflow that is more uniform across their area. As a result, a greater portion of the available heat transfer surface area may contribute effectively to heat rejection.

[0059] These concepts may provide improved airflow distribution and higher effective capacity within a given footprint and height envelope while reducing the need for additional heat exchange units. The approach may also allow fan speed and power requirements to be moderated relative to configurations that rely solely on top mounted fans. Optional adiabatic assist components, such as wetted media (e.g., adiabatic pads) or spray systems, may be incorporated to further enhance heat rejection while still using relatively small amounts of water.

[0060] It should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

[0061] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0062] Thus, while certain embodiments have been described, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as falling within the scope of the invention. For example, functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[0063] The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other implementations, which fall within the true spirit and scope of the present disclosure. Thus, to the maximum extent allowed by law, the scope of the present disclosure is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description. While various implementations of the disclosure have been described, it will be apparent to those of ordinary skill in the art that many more implementations are possible within the scope of the disclosure. Accordingly, the disclosure is not to be restricted except in light of the attached claims and their equivalents.

Examples

Embodiment Construction

[0021]The terminology used below may be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific examples of the present disclosure. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.

[0022]In this disclosure, the term “based on” means “based at least in part on.” The singular forms “a,”“an,” and “the” include plural referents unless the context dictates otherwise. The term “exemplary” is used in the sense of “example” rather than “ideal.” The terms “comprises,”“comprising,”“includes,”“including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article or apparatus that comprises a list of elements does not necessarily include only those elements, and may include other elements not ex...

Claims

1. An air cooled heat exchange assembly, comprising:a first heat exchange module configured to receive air and to transfer heat from a working fluid to the air;a second heat exchange module positioned adjacent to the first heat exchange module, the second heat exchange module being configured to receive air and to transfer heat from the working fluid to the air;a first fan module positioned adjacent to the second heat exchange module; anda second fan module positioned between the first heat exchange module and the second heat exchange module, the second fan module being configured to draw air through the first heat exchange module and to discharge the air toward the first fan module.

2. The air cooled heat exchange assembly of claim 1, further comprising a plenum positioned between the first heat exchange module and the second heat exchange module, wherein the second fan module is positioned within the plenum.

3. The air cooled heat exchange assembly of claim 1, wherein the second fan module includes an axial fan, a centrifugal fan, a mixed flow fan, or a plug fan.

4. The air cooled heat exchange assembly of claim 1, wherein the second fan module includes a single fan positioned centrally between the first heat exchange module and the second heat exchange module.

5. The air cooled heat exchange assembly of claim 1, wherein the second fan module includes a plurality of fans arranged in a single row extending across a width of the air cooled heat exchange assembly.

6. The air cooled heat exchange assembly of claim 1, wherein the second fan module includes a plurality of fans arranged in multiple rows between the first heat exchange module and the second heat exchange module.

7. The air cooled heat exchange assembly of claim 1, wherein the second fan module includes a plurality of fans that are individually controlled with an electronic controller.

8. The air cooled heat exchange assembly of claim 1, further comprising:at least one sensor configured to detect an operating condition of the air cooled heat exchange assembly; anda control system operatively connected to the second fan module, the first fan module, and the at least one sensor;wherein the first fan module is configured to exhaust air that has passed through the second heat exchange module to atmosphere;wherein the control system is configured to selectively operate the second fan module and the first fan module based on the operating condition.

9. The air cooled heat exchange assembly of claim 8, wherein the control system is configured to operate the second fan module independently of the first fan module in a first operating mode.

10. The air cooled heat exchange assembly of claim 8, wherein the control system is configured to operate the first fan module independently of the second fan module in a second operating mode.

11. The air cooled heat exchange assembly of claim 8, wherein the control system is configured to operate the second fan module and the first fan module simultaneously in a third operating mode, the control system being further configured to control a rotational speed of the second fan module and a rotational speed of the first fan module at the same speed or at different speeds in the third operating mode.

12. A method of using a heat exchange assembly including a first heat exchange module, a second heat exchange module positioned adjacent to the first heat exchange module, a second fan module positioned between the first heat exchange module and the second heat exchange module, and a first fan module positioned adjacent to the second heat exchange module, the method comprising:drawing ambient air through the first heat exchange module to transfer heat from a working fluid to the ambient air;operating the second fan module to draw air that has passed through the first heat exchange module and to add airflow energy between the first heat exchange module and the second heat exchange module; andoperating the first fan module to draw air through the second heat exchange module and to exhaust the air from the heat exchange assembly.

13. The method of claim 12, further comprising operating the second fan module and the first fan module simultaneously.

14. The method of claim 13, further comprising operating the second fan module at a first rotational speed and operating the first fan module at a second rotational speed different from the first rotational speed.

15. The method of claim 12, further comprising selectively operating at least one of the second fan module and the first fan module based on at least one operating condition.

16. An air cooled heat exchange assembly, comprising:at least two heat exchange modules arranged such that air passes sequentially through the at least two heat exchange modules, each heat exchange module including at least one heat exchange coil configured to transfer heat from a working fluid to the air;a first airflow module positioned to move air through the at least two heat exchange modules; andat least one additional airflow module including one or more fans configured to: (i) draw air that has passed through at least one of the at least two heat exchange modules, and (ii) discharge the air toward another of the at least two heat exchange modules,wherein the at least one additional airflow module is positioned at a location within the air cooled heat exchange assembly selected from: (i) between adjacent heat exchange modules of the at least two exchange modules, and (ii) within at least one heat exchange module of the at least two heat exchange modules.

17. The air cooled heat exchange assembly of claim 16, wherein the at least one additional airflow module is at least partially contained within a structural envelope of one heat exchange module of the at least two heat exchange modules.

18. The air cooled heat exchange assembly of claim 16, wherein the one or more fans of the at least one additional airflow module are oriented at an angle relative to a vertical direction such that the one or more fans direct air in a direction having both vertical and lateral components.

19. The air cooled heat exchange assembly of claim 16, wherein the at least two heat exchange modules include heat exchange coils arranged in an angled configuration that defines an interior region, and wherein the at least one additional airflow module is positioned within the interior region adjacent to inward-facing surfaces of the heat exchange coils.

20. The air cooled heat exchange assembly of claim 16, wherein the at least two heat exchange modules include at least three heat exchange modules arranged vertically, and wherein the at least one additional airflow module includes a plurality of airflow modules positioned at different elevations within the air cooled heat exchange assembly.

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