Heat removal management system with cascaded heat exchange for heat generating electronics

Abstract

The present invention relates generally to thermal management systems for data centers, and more particularly, to server heat removal systems (1) that employ heat exchange stages (11, 13), cold containment zones (7, 9), and a hybrid cooling architecture coupled to different cooling sources to improve energy efficiency.

Description

Technical Field

[0001] This invention generally relates to thermal management systems for data centers, and more specifically, to server heat removal systems that employ a heat exchange stage, a cold containment area, and a hybrid cooling architecture coupled to different cooling sources to improve energy efficiency. Background Technology

[0002] Modern data centers deploy high-density server racks, which generate significant heat loads. Efficient heat removal is crucial for ensuring operational reliability, preventing heat hotspots, and reducing energy consumption.

[0003] Conventional data center cooling solutions typically employ rear-door heat exchangers located downstream of the server racks, or alternatively, fan wall units, where such systems are coupled to a cooling loop that uses a chilled water system driven by mechanical chillers.

[0004] While chillers provide stable and controllable cooling capacity, they consume significant amounts of electrical power and negatively impact data center efficiency. Furthermore, the presence of water or coolant close to server racks introduces a risk of leakage, which could damage critical, high-value server equipment.

[0005] While fan wall units reduce water-related risks, they suffer from poor cooling efficiency due to the mismatch between lateral air exhaust and the front-to-back airflow direction of the server rack. This often results in ineffective air delivery and the formation of localized heat hotspots.

[0006] On the other hand, cooling towers can remove heat with much lower energy consumption, but are inherently limited by the surrounding environmental conditions.

[0007] However, existing cooling architectures generally lack a tiered thermal management approach, which prioritizes low-energy cooling sources, such as cooling towers, over high-energy chillers. Therefore, chillers are frequently operated even when cooling towers are capable of removing most of the heat load.

[0008] Therefore, there is a need for an improved server heat removal management system that reduces reliance on chillers while maintaining thermal stability and efficient operation within the data center. Summary of the Invention

[0009] This invention relates to a heat removal management system for data centers, and more specifically, to a cascaded heat exchange architecture that enables the tiered removal of heat from high-density server racks using multiple cooling sources with different energy efficiencies.

[0010] Therefore, the main objective of this invention is to provide a heat removal management system for data centers that reduces reliance on energy-intensive mechanical chillers by prioritizing the use of low-energy heat removal sources such as cooling towers, while maintaining effective thermal control within the data center environment.

[0011] Another object of the present invention is to provide a hierarchical thermal management architecture in which heat removal is performed sequentially in multiple containment zones, thereby achieving thermal equilibrium before final heat dissipation.

[0012] Another objective of this invention is to achieve flexible operation (including partial or complete chiller bypass) under changing environmental and load conditions without compromising server reliability.

[0013] Another objective of this invention is to improve the overall energy efficiency and power usage effectiveness (PUE) of data centers by intelligently distributing heat load among different cooling sources.

[0014] The additional objects of the invention will become apparent upon understanding the following detailed description of the invention or upon employing the invention in practice.

[0015] According to a preferred embodiment of the present invention, the following is provided:

[0016] A heat removal management system for heat-generating electronic equipment with cascaded heat exchange includes multiple cold containment zones arranged sequentially along an airflow path, each cold containment zone being associated with a corresponding heat exchange stage.

[0017] Exhaust air from the server rack first flows into a first cold containment zone, where heat is removed by a first heat exchange stage; and then flows into a second cold containment zone, where additional heat is removed by a second heat exchange stage. The heat exchange stages can be arranged in series so that heat is removed in stages before the air is exhausted from the system.

[0018] Each heat exchange stage is thermally coupled to a corresponding cooling circuit, wherein a first heat exchange stage is coupled to at least one evaporative heat dissipation unit circuit to remove a first portion of the heat from the server exhaust air using low-energy cooling; and a second heat exchange stage is coupled to a refrigeration unit circuit to remove the remaining heat. The thermal coupling can be direct or indirect and can include conduits, manifolds, or intermediate heat transfer components.

[0019] By removing heat from the cascaded containment zone, the system reduces the operation of the cooling units, improves overall energy efficiency, and maintains a stable operating temperature within the data center.

[0020] According to a preferred embodiment of the present invention, a heat removal management system with cascaded heat exchange for heat-generating electronic equipment is also provided, comprising:

[0021] At least one first cold containment area is arranged downstream of a single rack assembly or a plurality of rack assemblies arranged in a row along an airflow path and is configured to receive exhaust air from the single rack assembly or the plurality of rack assemblies arranged in a row.

[0022] At least one first heat exchange stage, the first heat exchange stage being thermally coupled to a first cold containment area and configured to remove a first portion of thermal energy from the exhaust air;

[0023] At least one second cold containment area, the at least one second cold containment area being arranged downstream of the first heat exchange stage along the airflow path and configured to receive air leaving the first heat exchange stage; and;

[0024] The second heat exchange stage, thermally coupled to the second cold containment area, is a second part configured to remove thermal energy from the air.

[0025] The exhaust air flows sequentially through the first cold containment zone, the first heat exchange stage, the second cold containment zone, and the second heat exchange stage to perform staged heat removal.

[0026] The energy efficiencies of the first heat exchange stage and the second heat exchange stage are different.

[0027] Optionally, the first cold containment area and the heat exchange stage are directly thermally coupled without any other structures or components.

[0028] Optionally, the first heat exchange stage is thermally coupled to at least one evaporative heat exhaust unit.

[0029] Optionally, the evaporative heat dissipation unit includes at least one of a cooling tower, a mixing cooling tower, a dry cooler, an adiabatic cooler, and a fluid cooler.

[0030] Optionally, the second heat exchange stage is thermally coupled to at least one refrigeration unit.

[0031] Optionally, the refrigeration unit includes at least one of a chiller, a heat pump, a packaged refrigeration unit, and a modular refrigeration unit.

[0032] Optionally, the energy efficiency of the first heat exchange stage is greater than that of the second heat exchange stage. Since the first heat exchange stage does not require the use of cold water, its energy efficiency is higher than that of the second heat exchange stage. Therefore, compared with a single-stage system, the overall efficiency of this two-stage cascade system is higher.

[0033] Optionally, the airflow path is arranged in a straight line, which includes both completely straight lines and near-straight lines.

[0034] According to a preferred embodiment of the present invention, a method for removing heat from heat-generating electronic equipment is also provided, comprising:

[0035] The exhaust air from the electronic equipment is directed into the first cold containment area;

[0036] The first heat exchange stage is used to remove the first portion of the heat energy from the exhaust air;

[0037] The partially cooled air is directed into the second cooling sealing zone; and

[0038] The second heat exchange stage removes a second portion of the heat energy from the air.

[0039] Thermal energy is removed in stages.

[0040] Compared to conventional cascaded cooling systems that rely on complex parallel airflow paths, multiple branched pressurization chambers, or distributed containment structures, this invention employs a simplified series airflow architecture while maintaining the energy efficiency benefits of staged heat removal. Specifically, this invention sequentially arranges multiple heat exchange stages downstream of a continuous cold containment zone along a substantially single airflow path, thereby enabling controlled and progressive heat extraction without introducing the complexity of airflow branching or crossflow.

[0041] This simplified airflow configuration offers technical advantages, including improved airflow predictability, reduced pressure loss, and simplified air management within data centers. Consequently, power or electrical consumption can be reduced while maintaining effective heat removal performance. Therefore, this invention demonstrates that the high energy efficiency traditionally associated with structurally complex cascaded cooling systems can be achieved using a series containment and heat exchange arrangement that is both thermally efficient and aerodynamically simplified (which is not readily apparent in conventional data center cooling architectures). Attached Figure Description

[0042] Other aspects and advantages of the invention will be understood after studying the specific embodiments in conjunction with the accompanying drawings, in which:

[0043] Figure 1 A perspective view of a heat removal management system for heat-generating electronic equipment with cascaded heat exchange, according to a preferred embodiment of the present invention, is shown.

[0044] Figure 2 It shows Figure 1 A schematic top view of a heat removal management system for heat-generating electronic equipment with cascaded heat exchange.

[0045] Figure 3 A schematic plan view of a heat removal management system for heat-generating electronic equipment with cascaded heat exchange is shown, illustrating the airflow path, heat exchange stages, fluid circulation loop, and representative temperature distribution for staged heat removal. Detailed Implementation

[0046] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the invention. However, those skilled in the art will understand that the invention can be practiced without these specific details. In other instances, well-known methods, procedures, and / or components have not been described in detail so as not to obscure the invention.

[0047] The invention will be more clearly understood from the following description of embodiments of the invention given by way of example only with reference to the accompanying drawings, which are not drawn to scale.

[0048] As used herein in this disclosure and the appended claims, the singular forms “a” and “the” include plural indicators unless the context clearly indicates or otherwise suggests otherwise.

[0049] Throughout this disclosure and claims, the word “comprise” and variations thereof (such as “comprising” and “comprises”) mean “including, but not limited to” and are not intended to exclude, for example, other components, integrals, or steps. “Exemplary” means “example of…” and is not intended to convey indications of preferred or ideal embodiments; “such as” is not used in a limiting sense but for illustrative purposes.

[0050] Embodiments of the present invention generally relate to a heat removal management system (1) with cascaded heat exchange for heat-generating electronic equipment such as servers, and more particularly, to a multi-stage containment cooling architecture configured to sequentially extract heat energy from server exhaust air using multiple thermally coupled heat exchange stages in fluid communication with at least one refrigeration unit (3) and at least one evaporative heat rejection unit (5).

[0051] refer to Figure 1 and Figure 2 The modular data hall enclosure includes multiple rack assemblies (R) arranged in a linear row. Each rack assembly (R) houses heat-generating electronics, such as servers, storage devices, and networking equipment. The heat removal management system (1) of the present invention includes multiple cold containment zones (7, 9) arranged sequentially along an airflow path downstream of the rack assembly (R).

[0052] In one embodiment, a first cold containment zone (7) is configured to receive exhaust air from the rack assembly (R) and direct the exhaust air toward a first heat exchange stage (11) to remove a first portion of the thermal energy. A second cold containment zone (9) is arranged downstream of the first heat exchange stage (11) along the airflow path and is configured to receive air leaving the first heat exchange stage (11) and direct the air toward a second heat exchange stage (13) for further thermal energy removal.

[0053] The first cold containment zone (7) serves to receive, collect, and homogenize the exhaust air emanating from the rack assembly (R), which still retains a significant amount of unresolved thermal energy. This first cold containment zone promotes temperature equilibrium, uniformity, and stabilization prior to heat extraction. The first heat exchange stage (11) is thermally associated with the first cold containment zone (7) and is configured to transfer heat from the homogenized airflow to the cooling medium.

[0054] Air exiting the first heat exchange stage (11) is directed into the second cold containment zone (9), which serves to receive, collect, and further homogenize the partially cooled airflow, thereby promoting additional temperature equalization before subsequent heat extraction. The second heat exchange stage (13) is thermally associated with the second cold containment zone (9) and is configured to remove residual heat from the airflow before the air is discharged for recirculation or reuse within the data hall.

[0055] Each heat exchange stage (11, 13) may include one or more heat exchangers and may optionally include airflow initiation devices such as fans to enhance heat transfer, or alternatively rely on pressure differentials generated by server airflow. The cold containment area (7, 9) and heat exchange stages (11, 13) may be implemented in a modular form and may be associated with individual racks, multiple racks, or rows of racks, thereby allowing for localized and efficient extraction of thermal energy.

[0056] In a preferred embodiment, the second heat exchange stage (13) includes a rear door heat exchanger, such that exhaust air exiting from the second cold containment zone (9) passes through the rear door heat exchanger before being discharged. The rear door heat exchanger may include one or more heat exchanger cores and may optionally include one or more fans for facilitating airflow through the heat exchanger cores. However, it should be understood that the second heat exchange stage (9) is not limited to a rear door configuration and may alternatively be implemented using other types of heat exchanger arrangements positioned along the airflow path.

[0057] In some embodiments, the heat removal management system (1) also includes a central thermal plant configured to supply circulating heat exchange fluid to multiple heat exchange stages (11, 13).

[0058] Multiple fluid distribution conduits (15) are fluidly coupled to the first heat exchange stage (11) and the second heat exchange stage (13). The fluid distribution conduits (15) are configured to deliver and return circulating heat exchange fluid between the heat exchange stages (11, 13) and the central heat and cold source station, thereby enabling continuous heat transfer.

[0059] The fluid distribution conduit (15) may include: one or more supply conduits configured to deliver cooled heat exchange fluid to heat exchange stages (11, 13); and one or more return conduits configured to return warmed heat exchange fluid to a central heating / cooling station. In some embodiments, the heat exchange fluid includes water, a water-glycol mixture, or any other suitable heat transfer medium.

[0060] In one embodiment, a first heat exchange stage (11) is thermally coupled to an evaporative heat dissipation unit (5) via a first set of supply and return conduits (17). The evaporative heat dissipation unit (5) is configured to dissipate heat energy to the external environment using evaporation and / or ambient heat exchange processes. The evaporative heat dissipation unit (5) may include, but is not limited to, one or more cooling towers, hybrid cooling towers, dry coolers, adiabatic coolers, fluid coolers, or combinations thereof.

[0061] In one embodiment, the second heat exchange stage (13) is thermally coupled to the refrigeration unit (3) via a second set of supply and return conduits (19). The refrigeration unit (3) is configured to actively remove heat energy from the circulating heat exchange fluid using a mechanical or thermodynamic refrigeration cycle. The refrigeration unit (3) may include, but is not limited to, one or more chillers, heat pumps, encapsulated refrigeration units, modular chillers, or combinations thereof.

[0062] Each of the first and second group of supply and return conduits (17, 19) may include a chilled fluid supply line and a chilled fluid return line (17a, 17b, 19a, 19b) to enable controlled circulation of the heat exchange fluid to and from each heat exchange stage (11, 13). Valves, pumps, sensors, and control logic can be used to regulate the flow rate, temperature, and pressure of the circulating heat exchange fluid to dynamically distribute the heat load between the evaporative heat exhaust unit (5) and the refrigeration unit (3).

[0063] Optionally, the arrangement of the chilled fluid supply lines and chilled fluid return lines can be perpendicular to the airflow path.

[0064] In some embodiments, the central heating and cooling station can operate the evaporative heat dissipation unit (5) and the cooling unit (3) independently, concurrently, or selectively based on environmental conditions, heat demand, or system operating modes. The system (1) may also include bypass ducts and control valves configured to selectively route circulating heat exchange fluid to one or both of the first and second heat exchange stages (11, 13).

[0065] This operating principle is in Figure 3 The figure further illustrates an exemplary embodiment of a heat removal management system (1) that combines an evaporative heat removal unit (5) and a refrigeration unit (3) operating in a cascade configuration to improve overall energy efficiency.

[0066] like Figure 3 As shown, cold air is supplied to the data hall and drawn into rack assemblies (R), where it absorbs heat generated by electronic equipment. The heated exhaust air leaving the rack assemblies (R) enters a first cold containment zone (7) and is directed to a first heat exchange stage (11), which is thermally coupled to an evaporative heat dissipation unit (5). A first portion of the heat energy is transferred from the exhaust air to the circulating heat exchange fluid and discharged to the external environment via the evaporative heat dissipation unit (5).

[0067] The partially cooled air leaving the first heat exchange stage (11) is then directed into the second cold containment area (9) and subsequently to the second heat exchange stage (13), which is thermally coupled to the refrigeration unit (3). The remaining residual heat energy in the airflow is further removed by the second heat exchange stage (13) before the air is discharged for recirculation or reuse in the data hall.

[0068] By sequentially removing heat energy using an evaporative heat removal unit (5) before employing the refrigeration unit (3), the system (1) reduces its reliance on energy-intensive refrigeration processes while maintaining a stable operating temperature for the rack assembly (R). This cascaded heat exchange arrangement enables efficient utilization of low-energy heat removal capacity and improves overall system energy efficiency under a wide range of operating conditions.

[0069] exist Figure 3 In the embodiments shown, the two-digit values ​​marked along the airflow path and fluid flow path represent example temperature values ​​of the air and circulating heat exchange fluid at corresponding locations within the system (1). These temperature values ​​are provided for illustrative and relative comparison purposes only and are not intended to limit the scope of the invention.

[0070] During operation, regulated supply air is delivered to the rack assembly (R) and drawn through the heat-generating electronics. For example... Figure 3 As shown, supply air can enter the rack (R) at a temperature of approximately 26°C. The air absorbs the heat generated by the heat-generating electronic equipment and leaves the rack (R) as heated exhaust air.

[0071] The heated exhaust air is directed into the first cooled containment zone (7), which is configured as an insulated pressurization chamber to homogenize the heated exhaust air. The exhaust air entering the first containment zone (7) can reach temperatures on the order of approximately 44°C, although other temperatures may occur depending on equipment load, airflow rate, and facility configuration.

[0072] The first heat exchange stage (11) is located between the first containment zone (7) and the second containment zone (9). The first heat exchange stage (11) is configured to transfer a portion of the thermal energy from heated air to the circulating heat exchange fluid. As the air passes through or through the first heat exchange stage (11), the air temperature decreases to an intermediate temperature. In the illustrated embodiment, the air temperature decreases from approximately 44°C to approximately 35°C, such as Figure 3 As shown. The extracted heat energy is transported by the heat exchange fluid through the fluid distribution conduit (15) toward the evaporative heat dissipation unit (5) for discharge or further processing.

[0073] Part of the cooled air leaving the first heat exchange stage (11) flows into the second containment zone (9), which forms a second controlled airflow chamber configured to further stabilize and regulate the airflow before discharge or recirculation. A second heat exchange stage (13) is located within or associated with the second containment zone (9), which further removes residual heat energy from the airflow and transfers this energy to the circulating heat exchange fluid.

[0074] After passing through the second heat exchange stage (13), the air temperature can be further reduced to approximately 26 °C, such as Figure 3 As shown, it can be discharged to the upper return air area or recirculated within the data hall.

[0075] The multi-stage heat extraction process achieves gradual temperature reduction, rather than a single high-lift cooling step, thereby improving heat exchange efficiency and reducing cooling energy requirements.

[0076] In the illustrated embodiment, the first heat exchange fluid circulating between the evaporative heat dissipation unit (5) and the first heat exchange stage (11) can be supplied to the first heat exchange stage (11) at a temperature of approximately 30°C and can be returned to the evaporative heat dissipation unit (5) at approximately 35°C after absorbing heat energy from the discharge control. The evaporative heat dissipation unit (5) removes heat energy from the first heat transfer fluid and returns the fluid to the first heat exchange stage (11) at a reduced temperature for continued circulation.

[0077] The second heat exchange fluid circulating between the refrigeration unit (3) and the second heat exchange stage (13) can be supplied to the second heat exchange stage (13) at a temperature of about 10°C and can be returned to the refrigeration unit (3) at about 15°C after absorbing heat energy from the airflow. The refrigeration unit (3) extracts heat energy from the second heat exchange fluid and transfers this energy to the evaporative heat discharge loop for eventual discharge to the surrounding environment.

[0078] In some embodiments, depending on weather conditions, ambient temperature and operating environment, the system (1) may use a control valve (21) to dynamically reconfigure the fluid flow path to selectively enable or disable one or more cooling sources while maintaining the tiered heat removal function.

[0079] refer to Figure 3 Under exemplary operating conditions, the evaporative heat dissipation unit (5) may supply a smaller proportion of the circulating heat transfer fluid to the first heat exchange stage (11), such as about 30 percent (30%), while the refrigeration unit (3) may supply a larger proportion (such as about 70 percent (70%)) of the circulating heat transfer fluid to the second heat exchange stage (13), while maintaining substantially the same proportion in the return flow.

[0080] Multiple control valves (21) can be arranged within the fluid distribution network, particularly along the supply conduit, to allow selective routing and partial cross-flow between fluid paths. The fluid delivered from the evaporative heat dissipation unit (5) can be selectively divided into multiple flow paths by the control valves (21), such that a first portion of the fluid (e.g., about thirty percent (30%)) is directed to the first heat exchange stage (11), while a second portion (e.g., about seventy percent (70%)) is routed toward the refrigeration unit (3) for further thermal conditioning before being supplied to the second heat exchange stage (13).

[0081] On the return side, the corresponding flow ratio can also be maintained, wherein approximately 30 percent (30%) of the return fluid from the first heat exchange stage (11) is directed back to the evaporative heat dissipation unit (5), while approximately 70 percent (70%) of the return fluid from the second heat exchange stage (13) is directed to the refrigeration unit (3), and thereafter the corresponding return flow can be reintroduced in the common return duct leading to the evaporative heat dissipation unit (5).

[0082] It is also conceivable that the control valve (21) may be additionally or alternatively located along the return duct and configured to selectively distribute the return fluid in a corresponding proportion or in another proportion determined by system operating conditions, thermal load or control logic.

[0083] While the invention has been shown and described in preferred embodiments to illustrate the superior results and advantages obtained by the invention compared to the prior art, the invention is not limited to these specific embodiments. Therefore, the forms of the invention shown and described herein are to be considered illustrative only, and other embodiments, as set forth in the appended claims, may be chosen without departing from the scope of the invention. The scope of the invention includes numerous alternatives, modifications, and equivalents. Certainly, there are many alternative ways to configure and implement the invention to suit specific installations and environments, while providing different functional and mechanical results.

Claims

1. A heat removal management system (1) for heat-generating electronic equipment with cascaded heat exchange, comprising: At least one first cold containment area (7) is arranged downstream of a single rack assembly (R) or a plurality of rack assemblies (R) arranged in a row along an airflow path and is configured to receive exhaust air from the single rack assembly (R) or the plurality of rack assemblies (R) arranged in a row. At least one first heat exchange stage (11) is thermally coupled to the first cold containment area (7) and configured to remove a first portion of thermal energy from the exhaust air; At least one second cold containment area (9) is arranged downstream of the first heat exchange stage (11) along the airflow path and is configured to receive air leaving the first heat exchange stage (11); as well as; The second heat exchange stage (13), which is thermally coupled to the second cold containment area (9) and configured to remove heat energy from the air, is a second part of the process. The exhaust air flows sequentially through the first cold containment area (7), the first heat exchange stage (11), the second cold containment area (9), and the second heat exchange stage (13) to perform staged heat removal; The first heat exchange stage and the second heat exchange stage have different energy efficiencies.

2. The heat removal management system (1) for heat-generating electronic equipment with cascaded heat exchange as claimed in claim 1, wherein the first heat exchange stage (11) is thermally coupled to at least one evaporative heat dissipation unit (5).

3. The heat removal management system (1) for heat-generating electronic equipment with cascaded heat exchange as described in claim 2, wherein the evaporative heat removal unit (5) includes at least one of a cooling tower, a hybrid cooling tower, a dry cooler, an adiabatic cooler, and a fluid cooler.

4. A heat removal management system (1) for heat-generating electronic equipment with cascaded heat exchange as claimed in claim 1 or 2, wherein the second heat exchange stage (13) is thermally coupled to at least one refrigeration unit (3).

5. The heat removal management system (1) for heat-generating electronic equipment with cascaded heat exchange as described in claim 4, wherein the refrigeration unit (3) includes at least one of a chiller, a heat pump, a packaged refrigeration unit, and a modular refrigeration unit.

6. A method for removing heat from heat-generating electronic equipment, comprising: The exhaust air from the electronic equipment is directed into the first cold containment area (7); The first portion of the heat energy is removed from the exhaust air using the first heat exchange stage (11); The partially cooled air is directed into the second cooling sealing zone (9); as well as The second portion of the heat energy is removed from the air using the second heat exchange stage (13). The heat energy is removed in a stepped manner.

7. The heat removal management system (1) for heat-generating electronic equipment with cascaded heat exchange as described in claim 1, 2 or 3, wherein the energy efficiency of the first heat exchange stage is greater than the energy efficiency of the second heat exchange stage.

8. The heat removal management system (1) for heat-generating electronic equipment as claimed in claim 1, wherein the airflow path is arranged in a straight line.

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