# US 11,910,577 B2 · Staged cooling for secondary coolant in datacenter cooling systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,910,577 B2 - Document ID: US11910577B2 - Status: Granted - Kind: B2 - Application number: 17/404,098 - Filed: 2021-08-17 - Published: 2023-02-23 - Granted: 2024-02-20 - Earliest claimed: 2021-08-17 - Assignees: NVIDIA Corporation - Applicants: Nvidia Corporation - Inventors: Ali Heydari - Web page: https://patentgrep.com/patent/US11910577B2 ## CPC - H05K 7/20836: {Thermal management, e.g. server temperature control} - H05K 7/2079: {within rooms for removing heat from cabinets} - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract Systems and methods for cooling a datacenter are disclosed. In at least one embodiment, a hybrid coolant distribution unit (HCDU) provides first stage cooling of secondary coolant returning from at least one cold plate in a liquid to air heat exchanger (L2AHE) and provides second stage cooling in a liquid to liquid heat exchanger (L2LHE) for secondary coolant exiting an L2AHE using varying flow rates of a primary coolant based in part on a residual temperature that is determined for such secondary coolant exiting an L2AHE. ## Claims ### Claim 1 A datacenter cooling system, comprising: a hybrid coolant distribution unit (HCDU) comprising a liquid to air heat exchanger (L2AHE) and a liquid to liquid heat exchanger (L2LHE), the L2AHE to provide first stage cooling of secondary coolant returning from at least one cold plate, and the L2LHE to provide second stage cooling for the secondary coolant exiting the L2AHE using varying flow rates of a primary coolant, the varying flow rates based at least in part on a determination that a temperature of cooling air for the L2AHE is above a threshold temperature. ### Claim 2 (depends on 1) The datacenter cooling system of claim 1, further comprising: at least one processor to determine a residual temperature for the secondary coolant exiting the L2AHE based on the determination that the temperature of cooling air for the L2AHE is above the threshold temperature, and to cause at least one flow controller to provide the primary coolant at the varying flow rates to address the residual temperature determined for the secondary coolant. ### Claim 3 (depends on 1) The datacenter cooling system of claim 1, further comprising: at least one first flow controller to provide the primary coolant, at the varying flow rates, to the L2LHE; and at least one second flow controller to provide the secondary coolant to interface with the primary coolant in the L2LHE. ### Claim 4 (depends on 1) The datacenter cooling system of claim 1, further comprising: one or more air inlets associated with the HCDU to enable external air that is cooled externally relative to the datacenter cooling system or to enable internal air from a hot aisle or a cold aisle to cool the secondary coolant in the L2AHE. ### Claim 5 (depends on 1) The datacenter cooling system of claim 1, further comprising: at least one processor to receive sensor inputs from sensors associated with the secondary coolant at an exit or an entrance of an L2AHE, the at least one processor to determine a change in a coolant state based in part on the sensor inputs and to cause at least one flow controller to change a flow of the primary coolant to address a residual temperature determined for the secondary coolant. ### Claim 6 (depends on 5) The datacenter cooling system of claim 5, further comprising: one or more neural networks to receive the sensor inputs and to infer the change in the coolant state. ### Claim 7 (depends on 1) The datacenter cooling system of claim 1, further comprising: at least one processor to determine that a temperature of air from a hot aisle is above a threshold, the at least one processor to cause external air to cool the secondary coolant or to cause one or more flow controllers to provide the primary coolant to cool the secondary coolant. ### Claim 8 (depends on 1) The datacenter cooling system of claim 1, further comprising: at least one processor to determine a residual temperature from sensor inputs or to estimate the residual temperature from workloads associated with a computing device to be supported by the datacenter cooling system. ### Claim 9 (depends on 1) The datacenter cooling system of claim 1, further comprising: at least one sensor associated the secondary coolant at an exit or an entrance of the L2AHE to provide sensor inputs that is to be used to cause at least one flow controller to change a flow of the primary coolant to address a residual temperature determined for the secondary coolant. ### Claim 10 (depends on 1) The datacenter cooling system of claim 1, further comprising: at least one first flow controller to control flow of the secondary coolant in the L2LHE, wherein a first part of the secondary coolant is cooled by the primary coolant to address a residual temperature in the secondary coolant and a second part of the secondary coolant is cooled in the L2AHE. ### Claim 11 A processor comprising one or more circuits and associated with a hybrid coolant distribution unit (HCDU) having a liquid to air heat exchanger (L2AHE) and a liquid to liquid heat exchanger (L2LHE), the one or more circuits to determine a residual temperature for a secondary coolant exiting a L2AHE based at least in part on a determination that a temperature of cooling air for the L2AHE is above a threshold temperature, the L2AHE to provide first stage cooling of secondary coolant returning from at least one cold plate, the processor to cause the L2LHE to provide second stage cooling for the secondary coolant exiting the L2AHE using varying flow rates of a primary coolant based in part on the residual temperature. ### Claim 12 (depends on 11) The processor of claim 11, further comprising: an output to provide signals for the one or more flow controllers to enable the primary coolant to flow to the L2LHE at the varying flow rates. ### Claim 13 (depends on 11) The processor of claim 11, further comprising: an input to receive sensor inputs from sensors associated with the secondary coolant at an exit or an entrance of the L2AHE, the processor to determine a change in a coolant state based in part on the sensor inputs and to cause at least one flow controller to change a flow of the primary coolant to address the residual temperature determined for the secondary coolant. ### Claim 14 (depends on 13) The processor of claim 13, further comprising: one or more neural networks to receive the sensor inputs and to infer the change in the coolant state. ### Claim 15 (depends on 11) The processor of claim 11, further comprising: at least one logic unit to determine the residual temperature for the secondary coolant using sensor inputs or using an estimation based in part on a workload for at least one computing device. ### Claim 16 A method for datacenter cooling system, comprising: providing a hybrid coolant distribution unit (HCDU) comprising a liquid to air heat exchanger (L2AHE) and a liquid to liquid heat exchanger (L2LHE); determining cooling requirements for at least one computing device; enabling the L2AHE to provide first stage cooling of secondary coolant returning from at least one cold plate; and enabling the L2LHE to provide second stage cooling for the secondary coolant exiting the L2AHE using varying flow rates of a primary coolant, the varying flow rates based at least in part on a determination that a temperature of cooling air for the L2AHE is above a threshold temperature. ### Claim 17 (depends on 16) The method of claim 16, further comprising: determining, using at least one processor, a residual temperature for the secondary coolant exiting the L2AHE based at least in part on the determination that the temperature of cooling air for the L2AHE is above the threshold temperature; and causing at least one flow controller to provide the primary coolant at the varying flow rates to cool the secondary coolant. ### Claim 18 (depends on 16) The method of claim 16, further comprising: receiving, in at least one processor, sensor inputs from sensors associated with the secondary coolant at an exit or an entrance of the L2AHE; determining, using the at least one processor, a change in a coolant state based in part on the sensor inputs; and causing, using at least one flow controller, a change of a flow of the primary coolant to address a residual temperature determined for the secondary coolant in the L2LHE. ### Claim 19 (depends on 16) The method of claim 16, further comprising: determining, using at least one processor, a residual temperature from sensor inputs or from an estimation using workloads associated with a computing device to be supported by the datacenter cooling system. ### Claim 20 (depends on 16) The method of claim 16, further comprising: providing, using at least one sensor associated the secondary coolant at an exit or an entrance of the L2AHE, sensor inputs to at least one processor; and causing at least one flow controller to change a flow of the primary coolant to address a residual temperature determined for the secondary coolant.