CN-122002762-A - Cooling distribution unit with constant pressure and variable flow

Abstract

The invention relates to a cooling distribution unit with constant pressure and variable flow. A cooling distribution unit associated with at least one rack system of a data center includes a first cooling system having a primary cooling loop and including a heat exchanger through which a heat transfer fluid is configured to circulate. The second cooling system has a secondary cooling circuit and includes a pump through which a coolant is configured to circulate. The second cooling system is thermally coupled to the first cooling system at a heat exchanger. When the load at the first heat exchanger changes, the pressure at the pump remains constant.

Inventors

• M. Grabang
• P. A. Favre

Assignees

• 开利公司

Dates

Publication Date

20260508

Application Date

20251103

Priority Date

20241101

Claims (20)

1. 1. A cooling distribution unit associated with at least one rack system of a data center, the cooling distribution unit comprising: a first cooling system having a primary cooling circuit through which a heat transfer fluid is configured to circulate, the first cooling system comprising a heat exchanger; A second cooling system having a secondary cooling circuit through which a coolant is configured to circulate, the secondary cooling circuit including a pump, wherein the second cooling system is thermally coupled to the first cooling system at the heat exchanger, and Wherein the pressure at the pump remains constant as the load at the first heat exchanger varies.
2. 2. The cooling system of claim 1, wherein a load at the cooling distribution unit is controlled via operation of the pump.
3. 3. The cooling system of claim 1 or claim 2, wherein the pump fluidly connected to the secondary cooling circuit is a variable speed pump.
4. 4. A cooling system according to any one of claims 1 to 3, wherein a portion of the coolant output from the pump is selectively recirculated to the pump to increase the pressure at the pump.
5. 5. The cooling system of claim 4, further comprising a recirculation conduit having an inlet fluidly connected to the secondary cooling circuit downstream of the pump and an outlet fluidly connected to the secondary cooling circuit upstream of the pump.
6. 6. The cooling system of claim 5, wherein at least one of the inlets is fluidly connected to the secondary cooling circuit directly downstream of the pump, and the outlet is fluidly connected to the secondary cooling circuit directly upstream of the pump.
7. 7. The cooling system of claim 5 or claim 6, further comprising a valve disposed along the recirculation conduit, the valve operable to control flow of the coolant back to the inlet of the pump.
8. 8. The cooling system of any one of claims 1 to 7, wherein the pump operates in a region of stable operation when the load at the cooling distribution unit varies.
9. 9. The cooling system of claim 8, further comprising a controller, wherein the controller is configured to determine a differential pressure across the heat exchanger.
10. 10. The cooling system of claim 9, further comprising a first sensor disposed within the secondary cooling circuit upstream of the heat exchanger and a second sensor disposed within the secondary cooling circuit downstream of the heat exchanger, wherein the first sensor and the second sensor are operably coupled to the controller and are operable to sense pressure, a difference between pressure at the first sensor and pressure at the second sensor being the differential pressure across the heat exchanger.
11. 11. The cooling system of claim 10, wherein the controller is configured to: Comparing the differential pressure to a differential pressure set point to determine a difference between the differential pressure measured by the first and second sensors and the differential pressure set point, and At least one operating parameter of the pump is adjusted in response to the difference between the differential pressure measured by the first and second sensors and the differential pressure set point.
12. 12. The cooling system of any one of claims 11, wherein the at least one operating parameter of the pump is speed.
13. 13. The cooling system of claim 11 or claim 12, wherein the controller is configured to evaluate whether operation of the pump having the at least one operating parameter is within the region of stable operation.
14. 14. The cooling system of claim 13, wherein the controller is configured to: Regulating operation of the pump to a minimum flow and pressure required for operation in the region of stable operation, and A portion of the coolant output from the pump is recirculated to an inlet of the pump to increase pressure at the pump.
15. 15. A method of operating a cooling distribution unit, the method comprising: Circulating a heat transfer fluid through a primary cooling loop; circulating coolant through a secondary cooling circuit comprising a pump, wherein the cooling distribution circuit and the secondary cooling circuit are thermally coupled via a heat exchanger; Detecting differential pressure within the secondary cooling circuit, and A flow of coolant within the secondary cooling loop is selectively recirculated to the pump to maintain a constant pressure within the secondary cooling loop.
16. 16. The method of claim 15, wherein selectively recirculating the flow of coolant within the secondary cooling loop to the pump further comprises diverting a portion of the coolant provided at an outlet of the pump directly to an inlet of the pump.
17. 17. The method of claim 15 or claim 16, further comprising: comparing the differential pressure to a differential pressure set point, and At least one operating parameter of the pump is determined in response to a difference between the differential pressure and a differential pressure set point.
18. 18. The method of claim 17, further comprising: Determining that the operation of the pump having the at least one operating parameter to be determined is within a region of stable operation associated with the pump, and The at least one operating parameter is implemented.
19. 19. The method of claim 18, further comprising: Determining that operation of the pump having the at least one operating parameter to be determined is within a region of unstable operation associated with the pump; Regulating operation of the pump to a minimum flow and pressure associated with the region of stable operation, and A valve is opened to recirculate a portion of the flow of coolant output from the pump to the inlet of the pump.
20. 20. The method of any one of claims 17 to 19, wherein the at least one operating parameter of the pump is speed.

Description

Cooling distribution unit with constant pressure and variable flow Technical Field Exemplary embodiments relate to the field of thermal management, and more particularly, to thermal management of servers within a data center. Background "Data center" refers to the physical location of one or more servers. Data centers and servers housed within the data centers typically consume significant amounts of electrical power. Existing servers are designed to be at least partially cooled by an air stream. Such servers typically include one or more printed circuit boards having a plurality of operable heat generating devices mounted thereto. The printed circuit board is typically housed in a housing having vents configured to direct outside air from the data center into the housing, through the housing, and out of the housing. The air absorbs heat dissipated by the components and mixes with ambient air after being exhausted from the housing. The heated air of the data center is then cooled and recirculated using an air conditioner, thereby repeating the cooling process. Higher performance server components typically dissipate more power. However, the amount of heat that a conventional air-cooled cooling system may remove from a server is limited in part by the degree of available air flow and the air characteristics relative to the heat transfer capacity of the air. In order to increase the power density of the cooling system, liquid cooling is required. Liquid cooling allows for a significant increase in the heat dissipated from the server. Disclosure of Invention According to an embodiment, a cooling distribution unit associated with at least one rack system of a data center includes a first cooling system having a primary cooling circuit and including a heat exchanger through which a heat transfer fluid is configured to circulate. The second cooling system has a secondary cooling circuit and includes a pump through which a coolant is configured to circulate. The second cooling system is thermally coupled to the first cooling system at a heat exchanger. When the load at the first heat exchanger changes, the pressure at the pump remains constant. In addition to or as an alternative to one or more of the features described above, in further embodiments the load at the cooling distribution unit is controlled via operation of the pump. In addition to or as an alternative to one or more of the features described above, in further embodiments the pump fluidly connected to the secondary cooling circuit is a variable speed pump. In addition to or as an alternative to one or more of the features described above, in further embodiments, a portion of the coolant output from the pump is selectively recirculated to the pump to increase the pressure at the pump. In addition to or as an alternative to one or more of the features described above, in a further embodiment the recirculation conduit has an inlet fluidly connected to the secondary cooling circuit downstream of the pump and an outlet fluidly connected to the secondary cooling circuit upstream of the pump. In addition to or as an alternative to one or more of the features described above, in a further embodiment at least one of the inlets is fluidly connected to the secondary cooling circuit directly downstream of the pump and the outlet is fluidly connected to the secondary cooling circuit directly upstream of the pump. In addition to or as an alternative to one or more of the features described above, in further embodiments, a valve disposed along the recirculation conduit is operable to control the flow of coolant back to the inlet of the pump. In addition to or as an alternative to one or more of the features described above, in further embodiments, the pump operates in a region of stable operation when the load at the cooling distribution unit varies. In addition to or as an alternative to one or more of the features described above, in further embodiments, the controller is configured to determine a differential pressure across the heat exchanger. In addition to or as an alternative to one or more of the features described above, in a further embodiment the first sensor is arranged within the secondary cooling circuit upstream of the heat exchanger and the second sensor is arranged within the secondary cooling circuit downstream of the heat exchanger. The first sensor and the second sensor are operatively coupled to the controller and are operable to sense pressure. The difference between the pressure at the first sensor and the pressure at the second sensor is the differential pressure across the heat exchanger. In addition to or as an alternative to one or more of the features described above, in a further embodiment the controller is configured to compare the differential pressure to a differential pressure set point to determine a difference between the differential pressure measured by the first and second sensors and the differential pressure set point and to