Control systems for air-assisted and liquid-cooled enclosures

1. A method of cooling multiple servers housed in an enclosure in a computing facility, the enclosure including:

an internal space housing the multiple servers, an air inlet opposite an air outlet separated from each other by the internal space; and

a cooling system having:

an inlet manifold configured to provide a coolant to one or more computing units of the multiple servers;

an outlet manifold configured to collect the coolant flowing from the inlet manifold and past the one or more computing units of the multiple servers;

a heat exchanger configured to receive the coolant collected at the outlet manifold;

an air mover configured to force at least a portion of cooling air flowing from the air inlet of the enclosure toward the heat exchanger before exhausting via the air outlet of the enclosure;

a coolant reservoir containing the coolant; and

a plurality of pumps arranged in parallel, the plurality of pumps operatively in fluid communication with the coolant reservoir and the inlet manifold, the plurality of pumps being configured to move the coolant from the coolant reservoir to the inlet manifold; and

wherein the method includes:

detecting a pressure drop of the coolant flowing across the multiple servers between the inlet and outlet manifolds;

performing a comparison of the detected pressure drop to a setpoint;

automatically adjusting operations of the plurality of pumps in the cooling system in accordance with the performed comparison such that additional detected pressure drops are at or near the setpoint, wherein automatically adjusting operations of the plurality of pumps including turning on or turning off one of the plurality of pumps based on the performed comparison; and

wherein automatically adjusting operations of the plurality of pumps includes turning off one of the plurality of pumps when the detected pressure drop is below the setpoint.

2. The method of claim 1 , further comprising:

detecting a supply temperature of the coolant provided to the multiple servers at the inlet manifold;

performing a comparison of the detected supply temperature of the coolant to a setpoint; and

automatically adjusting operations of the air mover in the cooling system in accordance with the performed comparison such that additional detected supply temperatures of the coolant are at or near the setpoint.

3. The method of claim 2 wherein automatically adjusting operations of the air mover includes one or more of:

increasing a speed of the air mover when the detected supply temperature exceeds the setpoint;

decreasing the speed of the air mover when the detected supply temperature is below the setpoint; or

turning on an additional air mover in the cooling system when the detected supply temperature exceeds the setpoint.

4. The method of claim 2 , further comprising:

receiving an input indicating an addition, removal, or replacement of a server in the enclosure; and

upon receiving the input,

determining an expected change to the supply temperature of the coolant at the inlet manifold based on a heat generation characteristic of the server; and

automatically adjusting operations of the air mover using the determined expected change to the detected supply temperature in addition to the performed comparison.

5. The method of claim 1 wherein automatically adjusting operations of the plurality of pumps includes:

increasing a speed of one of the plurality of pumps when the detected pressure drop exceeds the setpoint;

determining whether the increased speed of the one of the plurality of pumps exceeds a threshold; and

in response to determining that the increased speed of the one of the plurality of pumps exceeds the threshold, turning on another one of the plurality of pumps.

6. The method of claim 1 wherein automatically adjusting operations of the plurality of pumps includes:

decreasing a speed of one of the plurality of pumps when the detected pressure drop is below the setpoint;

determining whether the decreased speed of the one of the plurality of pumps is below a threshold; and

in response to determining that the decreased speed of the one of the plurality of pumps is below the threshold, turning off the one of the plurality of pumps.

7. The method of claim 1 , further comprising:

receiving an input indicating an addition, removal, or replacement of a server in the enclosure; and

upon receiving the input,

determining an expected change to the detected pressure drop based on a flow characteristic of the addition, removal, or replacement of the server; and

automatically adjusting operations of the pump using the determined expected change to the detected pressure drop in addition to the performed comparison.

8. The method of claim 1 , wherein automatically adjusting operations of the plurality of pumps includes turning on the one of the plurality of pumps when the detected pressure drop exceeds a threshold.

9. A method of cooling multiple servers housed in an enclosure in a computing facility, the enclosure including:

an internal space housing the multiple servers, an air inlet opposite an air outlet separated from each other by the internal space; and

a cooling system having

an inlet manifold configured to provide a coolant to the multiple servers;

an outlet manifold configured to collect the coolant flowing from the inlet manifold and past the multiple servers;

a heat exchanger configured to receive the coolant collected at the outlet manifold;

an air mover configured to force at least a portion of cooling air flowing from the air inlet of the enclosure toward the heat exchanger before exhausting via the air outlet of the enclosure;

a coolant reservoir containing the coolant; and

a pump operatively in fluid communication with the coolant reservoir and the inlet manifold, the pump being configured to move the coolant from the coolant reservoir to the inlet manifold; and

wherein the method includes:

detecting a pressure drop of the coolant flowing across the multiple servers between the inlet and outlet manifolds;

performing a comparison of the detected pressure drop to a setpoint; and

automatically adjusting operations of the pump in the cooling system in accordance with the performed comparison such that additional detected pressure drops are at or near the setpoint, automatically adjusting the operations including one or more of:

increasing a speed of the pump when the detected pressure drop exceeds the setpoint;

decreasing the speed of the pump when the detected pressure drop is below the setpoint; or

turning on an additional pump arranged in parallel with the pump and in fluid communication with the coolant reservoir when the detected pressure drop exceeds the setpoint.

10. The method of claim 9 wherein automatically adjusting operations of the pump includes automatically adjusting operations of the air mover including one or more of:

increasing a speed of the air mover when a detected supply temperature exceeds a temperature setpoint;

decreasing the speed of the air mover when the detected supply temperature is below the temperature setpoint; or

turning on an additional air mover in the cooling system when the detected supply temperature exceeds the temperature setpoint.

11. The method of claim 9 further comprising:

receiving an input indicating an addition, removal, or replacement of a server in the enclosure; and

upon receiving the input,

determining an expected change to a supply temperature of the coolant at the inlet manifold based on a heat generation characteristic of the server; and

automatically adjusting operations of the air mover using the expected change to the supply temperature.

12. The method of claim 9 further comprising:

receiving an input indicating an addition, removal, or replacement of a server in the enclosure; and

upon receiving the input,

determining an expected change to the detected pressure drop based on a flow characteristic of the addition, removal, or replacement of the server; and

automatically adjusting operations of the pump using the determined expected change to the detected pressure drop.

13. The method of claim 9 , wherein automatically adjusting operation of the pump includes turning on the pump when the detected pressure drop exceeds a threshold.

14. A method of cooling multiple servers housed in an enclosure in a computing facility, the enclosure including:

an internal space housing the multiple servers, an air inlet opposite an air outlet separated from each other by the internal space; and

a cooling system having

an inlet manifold configured to provide a supply coolant to one or more computing units of the multiple servers;

an outlet manifold configured to collect a return coolant flowing from the inlet manifold and past the one or more computing units of the multiple servers, wherein the supply coolant removes heat from the multiple servers such that the return coolant is a higher temperature than the supply coolant;

an air-cooled heat exchanger configured to receive the return coolant collected at the outlet manifold;

an air mover configured to force at least a portion of cooling air flowing from the air inlet of the enclosure toward the heat exchanger before exhausting via the air outlet of the enclosure;

a coolant reservoir containing the supply coolant; and

a plurality of pumps arranged in parallel, the plurality of pumps operatively in fluid communication with the coolant reservoir and the inlet manifold, the plurality of pumps being configured to move the supply coolant from the coolant reservoir to the inlet manifold; and

wherein the method includes:

detecting a pressure drop of the supply coolant flowing across the multiple servers between the inlet and outlet manifolds and a supply temperature of the supply coolant at the inlet manifold; and

automatically adjust operations of the plurality of pumps to maintain the detected pressure drop at or near a pressure-drop setpoint while automatically adjusting operations of the air mover to maintain the supply temperature at or near a temperature setpoint, wherein automatically adjusting operations of the plurality of pumps including turning on or turning off one of the plurality of pumps based on a performed comparison of the detected pressure drop to the pressure-drop setpoint; and

wherein automatically adjusting operations of the plurality of pumps includes:

increasing a speed of one of the plurality of pumps when the detected pressure drop exceeds the pressure-drop setpoint;

determining whether the increased speed of the one of the plurality of pumps exceeds a threshold; and

in response to determining that the increased speed of the one of the plurality of pumps exceeds the threshold, turning on another one of the plurality of pumps.

15. The method of claim 14 wherein automatically adjusting operations of the air mover includes one or more of:

increasing a speed of the air mover when the detected supply temperature exceeds the temperature setpoint;

decreasing the speed of the air mover when the detected supply temperature is below the temperature setpoint; or

turning on an additional air mover in the cooling system when the detected supply temperature exceeds the temperature setpoint.

16. The method of claim 14 wherein automatically adjusting operations of the plurality of pumps includes one or more of:

increasing a speed of one of the plurality of pumps when the detected pressure drop exceeds the pressure-drop setpoint;

decreasing the speed of one of the plurality of pumps when the detected pressure drop is below the pressure-drop setpoint; or

turning on an additional pump of the plurality of pumps when the detected pressure drop exceeds the pressure-drop setpoint.

17. The method of claim 14 wherein automatically adjusting operations of the plurality of pumps includes turning off one of the plurality of pumps when the detected pressure drop is below the pressure-drop setpoint.

18. The method of claim 14 , wherein automatically adjusting operations of the plurality of pumps includes turning on the one of the plurality of pumps when the detected pressure drop exceeds a threshold.