EP-4739019-A1 - COOLING DISTRIBUTION UNIT WITH CONSTANT SUPPLY RETURN TEMPERATURE

EP4739019A1EP 4739019 A1EP4739019 A1EP 4739019A1EP-4739019-A1

Abstract

A cooling distribution unit (60) associated with at least one rack system (52) of a data center (50) includes a first cooling system (30) having a primary cooling circuit (31) through which a heat transfer fluid (R) is configured to circulate, a heat exchanger (38), a cooling system load (34, 40) arranged downstream from the heat exchanger (38) relative to a flow of the heat transfer fluid (R), and at least one valve (36). A second cooling system (32) having a secondary cooling circuit (33) through which a coolant (C) is configured to circulate includes a pump (68). The second cooling system (32) is thermally coupled to the first cooling system (30) at the heat exchanger (38). The heat transfer fluid (R) provided to the cooling system load (34, 40) has a first constant temperature as a load at the heat exchanger (38) varies.

Inventors

GRABON, MICHEL
FERVEL, Pierre Alain

Assignees

Carrier Corporation

Dates

Publication Date: 20260506
Application Date: 20251031

Claims (15)

A cooling distribution unit associated with at least one rack system of a data center, the cooling system comprising: a first cooling system having a primary cooling circuit through which a heat transfer fluid is configured to circulate, the first cooling system including a heat exchanger, and a cooling system load arranged downstream from the heat exchanger relative to a flow of the heat transfer fluid, and at least one valve; a second cooling system having a secondary cooling circuit through which a coolant is configured to circulate, the second 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 heat transfer fluid provided to the cooling system load has a first constant temperature as a load at the heat exchanger varies.
The cooling distribution unit of claim 1, wherein the heat transfer fluid provided to an inlet of the heat exchanger has a second constant temperature as the load at the cooling distribution unit varies, the second constant temperature being different than the first constant temperature.
The cooling distribution unit of claim 1 or claim 2, wherein the pump fluidly connected to the second cooling circuit is a variable speed pump.
The cooling distribution unit of any of claims 1-3, wherein the load at the heat exchanger is controlled via operation of the pump.
The cooling distribution unit of any of claims 1-4, wherein the at least one valve includes a first valve operable to control a flow of the heat transfer fluid to the heat exchanger and a second valve operable to control a flow of the heat transfer fluid to bypass the heat exchanger.
The cooling distribution unit of claim 5, further comprising a bypass conduit arranged in parallel with the heat exchanger relative to the flow of the heat transfer fluid, wherein the second valve is operable to control the flow of the heat transfer fluid through the bypass conduit.
The cooling distribution unit of claim 6, wherein the heat transfer fluid output from the heat exchanger is mixed with heat transfer fluid from the bypass conduit at a mixing point; optionally wherein heat transfer fluid output from the heat exchanger has a first temperature and the heat transfer fluid within the bypass conduit has a second temperature, and a mixture of the heat transfer fluid output from the heat exchanger and the heat transfer fluid from the bypass conduit is provided to the cooling system load having the constant temperature.
The cooling distribution unit of any of claims 5-7, wherein the first valve is located upstream from an inlet of the heat exchanger relative to a flow of the heat transfer fluid and the second valve is located upstream from the first valve relative to the flow of the heat transfer fluid and/or wherein the first valve is independently operable from the second valve.
The cooling distribution unit of any of claims 5-7, wherein the first valve and the second valve are integrally formed as a single three-way valve located upstream from an inlet of the heat exchanger relative to a flow of the heat transfer fluid.
The cooling distribution unit of any of claims 5-9, further comprising a controller operably coupled to the at least one valve and the pump, the controller being configured to operate the first valve to control a flow of the heat transfer fluid provided to the heat exchanger in response to a load at the cooling distribution unit; optionally wherein the controller is configured to operate the second valve to control a temperature of the heat transfer fluid provided to the cooling system load.
A method of operating a cooling distribution system, the method comprising: circulating a heat transfer fluid through a primary cooling circuit; circulating a coolant through a secondary cooling circuit, wherein the primary cooling circuit and the secondary cooling circuit are thermally coupled via a heat exchanger; detecting a temperature of the heat transfer fluid via a sensor, the sensor being positioned at a location between an outlet of the heat exchanger and a cooling system load arranged downstream from the heat exchanger relative to a flow of the heat transfer fluid; and controlling a flow of heat transfer fluid through the primary cooling circuit in response to the temperature detected by the sensor to maintain a constant temperature of the heat transfer fluid provided to the cooling system load.
The method of claim 11, wherein controlling a flow of the heat transfer fluid through the primary cooling circuit in response to the temperature detected by the sensor includes controlling a flow of the heat transfer fluid through a bypass conduit arranged in parallel with the heat exchanger; and/or wherein the method further comprises: comparing the temperature of the heat transfer fluid detected via the sensor to a return temperature set point to determine a difference between the temperature of the heat transfer fluid and the return temperature set point; and adjusting a flow of the heat transfer fluid through the primary cooling circuit in response to the difference between the temperature of the heat transfer fluid and the return temperature set point.
The method of claim 11 or 12, further comprising controlling the flow of the heat transfer fluid provided to the heat exchanger in response to a temperature of the coolant at a location downstream from the heat exchanger.
The method of claim 13, further comprising: sensing a temperature of the coolant at the location downstream from the heat exchanger via another sensor; comparing the temperature of the coolant at the location downstream from the heat exchanger with a temperature set point to determine a difference between the temperature of the coolant at the location downstream from the heat exchanger and the temperature set point; and adjusting the flow of the heat transfer fluid provided to the heat exchanger in response to the difference between the temperature of the coolant at the location downstream from the heat exchanger and the temperature set point.
The method of claim 11, 12 or 13, wherein a temperature of the heat transfer fluid at an inlet of the heat exchanger is constant.

Description

BACKGROUND Exemplary embodiments pertain to the art of thermal management, and more particularly, relate to thermal management of a server within a data center. A "data center" refers to the physical location of one or more servers. A data center and the servers housed within a data center typically consume a significant amount of electrical power. Existing servers are designed to be cooled at least partially by a flow of air. Such servers usually include one or more printed circuit boards having a plurality of operable heat-generating devices mounted thereto. The printed circuit boards are commonly housed in an enclosure having vents configured to direct external air from the data center into, through and out of the enclosure. The air absorbs heat dissipated by the components and after being exhausting from the enclosure, mixes with the ambient air. An air conditioner is then used to cool the heated air of the data center and to recirculate it, repeating the cooling process. Higher performance server components typically dissipate more power. However, the amount of heat that a conventional air-cooled cooling system can remove from a server is in part limited by the extent of the air flow available and air proprieties relative to heat transfer capacity of the air. To increase the power density of a cooling system, liquid cooling is required. Liquid cooling allows significant increase of dissipated heat from servers. BRIEF DESCRIPTION Viewed from a first aspect, 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 through which a heat transfer fluid is configured to circulate, a heat exchanger, a cooling system load arranged downstream from the heat exchanger relative to a flow of the heat transfer fluid, and at least one valve. A second cooling system having a secondary cooling circuit through which a coolant is configured to circulate includes a pump. The second cooling system is thermally coupled to the first cooling system at the heat exchanger. The heat transfer fluid provided to the cooling system load has a first constant temperature as a load at the heat exchanger varies. The heat transfer fluid provided to an inlet of the heat exchanger may have a second constant temperature as the load at the cooling distribution unit varies. The second constant temperature is different than the first constant temperature. The pump fluidly connected to the second cooling circuit may be a variable speed pump. The load at the heat exchanger may be controlled via operation of the pump. The at least one valve may include a first valve operable to control a flow of the heat transfer fluid to the heat exchanger and a second valve operable to control a flow of the heat transfer fluid to bypass the heat exchanger. A bypass conduit may be arranged in parallel with the heat exchanger relative to the flow of the heat transfer fluid. The second valve is operable to control the flow of the heat transfer fluid through the bypass conduit. The heat transfer fluid output from the heat exchanger may be mixed with heat transfer fluid from the bypass conduit at a mixing point. Optionally, heat transfer fluid output from the heat exchanger has a first temperature and the heat transfer fluid within the bypass conduit has a second temperature, and a mixture of the heat transfer fluid output from the heat exchanger and the heat transfer fluid from the bypass conduit is provided to the cooling system load having the constant temperature. Optionally, the first valve is located upstream from an inlet of the heat exchanger relative to a flow of the heat transfer fluid and the second valve is located upstream from the first valve relative to the flow of the heat transfer fluid. The first valve may be independently operable from the second valve. Optionally, the first valve and the second valve are integrally formed as a single three-way valve located upstream from an inlet of the heat exchanger relative to a flow of the heat transfer fluid. A controller may be operably coupled to the at least one valve and the pump. The controller is configured to operate the first valve to control a flow of the heat transfer fluid provided to the heat exchanger in response to a load at the cooling distribution unit. The controller may be configured to operate the second valve to control a temperature of the heat transfer fluid provided to the cooling system load. Viewed from a second aspect, a method of operating a cooling distribution system includes circulating a heat transfer fluid through a primary cooling circuit and circulating a coolant through a secondary cooling circuit. The primary cooling circuit and the secondary cooling circuit are thermally coupled via a heat exchanger. The method further including detecting a temperature of the heat transfer fluid via a sensor positioned at a location between an outlet of the heat exchanger and a cooling system loa