Liquid flow control based upon energy balance and fan speed for controlling exhaust air temperature

Patent metadata

Field	Value
Publication number	US-10146231-B2
Application number	US-201615017451-A
Country	US
Kind code	B2
Filing date	Feb 5, 2016
Priority date	Dec 21, 2015
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A computer-implemented method regulates exhaust air temperature from direct interface liquid-cooled (DL) nodes in a rack information handling system (RIHS). The method includes receiving a first input corresponding to a desired ambient temperature of an exterior space and a second input is corresponding to an amount of heat being dissipated from functional components operating within an interior space of at least one LC node. An ambient temperature reading of the exterior space is received. A flow rate is calculated for liquid flowing through an air-to-liquid heat exchange (ATLHE) subsystem that results in an amount of heat exchange in the ATLHE subsystem, which generates exhaust air at a temperature that causes a change in the ambient temperature towards the desired ambient temperature. The flow rate is dynamically adjusted of the liquid flowing through the ATLHE subsystem to the calculated flow rate.

First claim

What is claimed is:

1. A computer-implemented method comprising:
receiving a first input corresponding to a desired ambient temperature of an exterior space outside of and surrounding a direct-injection, liquid-cooled (DL) rack information handling system (RIHS), wherein the RIHS comprises at least one liquid cooled (LC) node within a block chassis and a corresponding air-to-liquid heat exchange (ATLHE) subsystem through which air passing through the LC node is channeled as exhaust air towards the exterior space;
receiving a second input corresponding to an amount of heat being dissipated from functional components operating within an interior space of the at least one LC node;
receiving a current ambient temperature reading of the exterior space;
calculating a flow rate for liquid flowing through the ATLHE subsystem that results in an amount of heat exchange in the ATLHE subsystem, which generates exhaust air at a temperature that causes a change in the ambient temperature towards the desired ambient temperature outside of the DL RIHS; and
dynamically adjusting the flow rate of the liquid flowing through the ATLHE subsystem to the calculated flow rate.

2. The method of claim 1 , wherein:
the ATLHE subsystem includes at least one block liquid controller and a corresponding liquid control valve that controls the flow rate of the liquid flowing through the ATLHE subsystem based on a value of a pulse width modulated (PWM) signal calculated by the at least one block liquid controller and transmitted to the corresponding liquid control valve; and
dynamically adjusting the flow rate of the liquid flowing through the ATLHE subsystem to the calculated flow rate further comprises:
generating a corresponding PWM signal that is proportional to the calculated flow rate; and
transmitting the corresponding PWM signal to the liquid control valve such that the liquid control valve moves to an open position that results in cooling liquid flow at the calculated liquid flow rate.

3. The method of claim 2 , further comprising:
determining whether the calculated flow rate is less than a block minimum flow rate;
in response to the calculated flow rate being less than block minimum flow rate, generating a PWM signal corresponding to the block minimum flow rate, and triggering the liquid control valve to move to a position corresponding to the block minimum flow rate;
determining whether the calculated flow rate is above a maximum flow rate cap;
in response to the calculated flow rate being above the maximum flow rate cap, adjusting the calculated flow rate to be equal to the maximum flow rate cap, and triggering the liquid control valve to move to a position corresponding to the maximum flow rate cap; and
in response to the calculated flow rate being above the block minimum flow rate and at or below the maximum flow rate cap, triggering the liquid control valve to move to a position corresponding to the calculated flow rate.

4. The method of claim 1 , wherein the second input comprises at least one of:
an amount of power consumed by each of the functional components operating within the interior space of the at least one LC node; and
a temperature reading by a temperature reading component placed in proximity to or within the interior space.

5. The method of claim 1 , wherein:
calculating the flow rate for liquid flowing through the LC subsystem further comprises:
calculating an amount of heat absorption required by the cooling liquid within the ATLHE subsystem to provide the exhaust air at a temperature that causes a change in the ambient temperature to the desired ambient temperature; and

calculating the amount of heat absorption further comprises;
determining a total amount of heat to be removed from the at least one LC node;
receiving a first temperature value of an incoming liquid to the ATLHE subsystem and a second temperature value of an outgoing liquid from the ATLHE subsystem; and
calculating the flow rate for liquid flowing through the ATLHE subsystem in part based on the first amount of heat to be removed from the at least one LC node and the incoming and outgoing liquid temperatures.

6. The method of claim 5 , wherein determining the total amount of heat to be removed from the at least one LC node further comprises:
determining a first amount of heat to be removed from processing components within the at least one LC node:
determining a second amount of heat to be removed from a plurality of other components within the at least one LC node; and
adding the first amount and second amount of heat to determine the total amount of heat, wherein the total amount of heat to be removed from the at least one LC node is the sum of the first and second amounts of heat.

7. The method of claim 1 , wherein calculating the flow rate for liquid flowing through the ATLHE subsystem further comprises:
retrieving control parameters associated with the block containing the at least one LC node, the control parameters comprising proportional, integral and derivative (PID) algorithm data;
determining a first difference between the calculated flow rate and a current flow rate;
calculating a pulse width modulated (PWM) signal change value using a PID algorithm based on the first difference and the control parameters; and
forwarding the PWM signal change value to the liquid control valve that controls the flow rate of the liquid flowing through the ATLHE subsystem based on a value of the PWM signal received at each of the at least one liquid control valves.

8. A liquid cooling system for a direct injection liquid cooled (DL) rack information handling system (RIHS) comprising:
a rack having at least one liquid cooled (LC) node within a block chassis;
a liquid cooling subsystem associated with the rack, the liquid cooling subsystem including:
at least one air-to-liquid heat exchange ATLHE subsystem that receives intake air at a first temperature and provides exhaust air at a second temperature based on a heat exchange gradient between cooling liquid flowing through the ATLHE subsystem and the ambient temperature of air being passed through the ATLHE subsystem;
a network of conduits that enables cooling liquid to flow through the at least one LC node and through the ATLHE subsystem, the network of conduits including an intake conduit that enables cooling fluid to be passed through the at least one LC node; and
at least one liquid control valve in fluid communication with, and controlling a rate of flow of cooling liquid through, corresponding fluid intake ports of the network of conduits;

a controller associated with the at least one LC node and communicatively coupled to the at least one liquid control valve and to at least one temperature measuring device; and
wherein the controller has firmware executing thereon that configures the controller to:
receive a first input corresponding to a desired ambient temperature of an exterior space outside of and surrounding the DL RIES;
receive a second input corresponding to an amount of heat being dissipated from functional components operating within an interior space of the at least one LC node;
receive a current ambient temperature reading of the exterior space;
calculate a flow rate for liquid flowing through the ATLHE subsystem that results in an amount of heat exchange in the ATLHE subsystem, which generates exhaust air at a temperature that causes a change in the ambient temperature towards the desired ambient temperature outside of the DL RIES; and
dynamically adjust the flow rate of the liquid flowing through the ATLHE subsystem to the calculated flow rate.

9. The liquid cooling system of claim 8 , wherein the liquid control valve controls the flow rate of the liqui

Assignees

• Dell Products Lp

Inventors

• Shelnutt Austin Michael
• North Travis C
• Helberg Christopher M

Classifications

• G05B15/02

  electric · CPC title

• H05K7/20781

  within cabinets for removing heat from server blades · CPC title

• G05D7/0629 Primary

  characterised by the type of regulator means · CPC title

• H05K7/20836 Primary

  Thermal management, e.g. server temperature control · CPC title

• H05K7/20736

  within cabinets for removing heat from server blades · CPC title