Thermal control system

• US 9,874,414 B1
• Filed: 12/06/2013
• Issued: 01/23/2018
• Est. Priority Date: 12/06/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google LLC (Alphabet Inc.)
• Inventors: Ong, Tony
• Primary Examiner(s): Shirsat, Vivek
• Application Number:
  US14/099,098
• Time in Patent Office: 1,509 Days
• Field of Search: 454184
• CPC Class Codes: F28F 27/00 Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus control arrangements in general G05
• CPC Class Codes: H05K 7/20572 within cabinets for removing heat from sub-racks, e.g. plenum
• CPC Class Codes: H05K 7/207 Thermal management, e.g. cabinet temperature control

Abstract

A thermal control system includes a chassis, one or more temperature sensors, a chassis controller, and an air mover module. The one or more temperature sensors and the air mover module are disposed on the chassis. The chassis controller is in communication with the one or more temperature sensors. The air mover module includes an air mover and an air controller. The air controller is in communication with the air mover, the one or more temperature sensors, and the chassis controller. In addition, the air controller receives periodic heartbeat signals from the chassis controller while the chassis controller operates in a healthy state. The chassis controller controls the air mover based on temperature signals of the one or more temperature sensors while operating in its healthy state.

Claims

1. A system comprising:

a chassis;

one or more temperature sensors disposed on the chassis;

a chassis controller in communication with the one or more temperature sensors; and

an air mover module disposed on the chassis and comprising;

an air mover; and

an air controller in communication with the air mover, the one or more temperature sensors, and the chassis controller, the air controller receiving periodic heartbeat signals from the chassis controller while the chassis controller operates in a healthy state;

wherein the chassis controller controls the air mover based on temperature signals of the one or more temperature sensors while operating in the healthy state, and

wherein, when the air controller fails to receive any heartbeat signals from the chassis controller for a failure threshold period of time, the air controller takes control of the air mover and controls the air mover based on the temperature signals of the one or more temperature sensors.

2. The system of claim 1, wherein the air controller:

determines a target air flow rate based on one or more temperature signals of the one or more temperature sensors to maintain a threshold temperature of an air volume of the chassis; and

adjusts an air flow of the air mover to move air at the target air flow rate.

3. The system of claim 2, further comprising non-transitory memory storing temperature signals of the one or more temperature sensors, the air controller accessing the one or more temperature signals from the memory.

4. The system of claim 3, wherein the chassis controller:

obtains temperatures signals of the one or more temperature sensors from the memory;

determines a target air flow rate based on the one or more temperature signals to maintain a threshold temperature of an air volume of the chassis;

adjusts an air flow of the air mover to move air at the target air flow rate; and

sends a heartbeat signal to the air controller.

5. The system of claim 1, wherein the air controller relinquishes control of the air mover back to the chassis controller after receiving a heartbeat signal again from the chassis controller.

6. The system of claim 5, wherein the air controller relinquishes control of the air mover to the chassis controller after receiving periodic heartbeat signals again from the chassis controller for a resume threshold period of time.

7. The system of claim 1, wherein the air controller sends an acknowledgement signal to the chassis controller in response to receiving a heartbeat signal.

8. The system of claim 1, wherein the air controller and the chassis controller share a temperature policy of maintaining a temperature of an air volume of the chassis within a threshold temperature range by adjusting an air flow of the air mover.

9. The system of claim 8, wherein the air controller receives the temperature policy from the chassis controller.

10. The system of claim 1, wherein the air controller:

monitors temperature signals of the one or more temperature sensors;

takes control of the air mover when a temperature of an air volume of the chassis is outside a threshold temperature range;

determines a target air flow rate based on the one or more temperature signals to maintain a threshold temperature of an air volume of the chassis; and

adjusts an air flow of the air mover to move air at the target air flow rate.

11. The system of claim 10, wherein the air controller relinquishes control of the air mover to the chassis controller after:

receiving a heartbeat signal from the chassis controller or periodically receiving heartbeat signals for a resume threshold period of time from the chassis controller; and

the temperature of the air volume of the chassis is within the threshold temperature range.

12. The system of claim 10, further comprising non-transitory memory storing temperature signals of the one or more temperature sensors, the air controller accessing the one or more temperature signals from the memory.

13. The system of claim 12, wherein the chassis controller:

accesses one or more temperature signals from the memory;

determines a target air flow rate based on the one or more temperature signals to maintain a threshold temperature of an air volume of the chassis;

adjusts an air flow of the air mover to move air at the target air flow rate; and

sends a heartbeat signal to the air controller.

14. A method of temperature control, the method comprising:

receiving periodic heartbeat signals from a chassis controller, the chassis controller only sending heartbeat signals while operating in a healthy state, the chassis controller controlling an air flow of an air mover of a chassis to maintain a threshold temperature of an air volume of the chassis; and

in response to failing to receive a heartbeat signal from the chassis controller for a failure threshold period of time;

determining a target air flow rate based on one or more temperature signals of temperature sensors disposed on the chassis to maintain the threshold temperature; and

adjusting the air flow of the air mover to move air at the target air flow rate based on the temperature signals of the one or more temperature sensors.

15. The method of claim 14, further comprising, in response to failing to receive a heartbeat signal from the chassis controller for a failure threshold period of time, adjusting the air flow of the air mover to move air to maintain a temperature of the air volume of the chassis within a threshold temperature range.

16. The method of claim 14, further comprising, in response to failing to receive a heartbeat signal from the chassis controller for a failure threshold period of time, obtaining the temperature signals from non-transitory memory, the memory storing temperature signals of the one or more temperature sensors.

17. The method of claim 14, further comprising, in response to receiving a heartbeat signal, sending an acknowledgement signal to the chassis controller.

18. The method of claim 14, further comprising, after failing to receive a heartbeat signal from the chassis controller for a failure threshold period of time, relinquishing control of the air mover to the chassis controller after receiving a heartbeat signal from the chassis controller.

19. The method of claim 18, further comprising relinquishing control of the air mover to the chassis controller after receiving a heartbeat signal from the chassis controller for a resume threshold period of time.

20. The method of claim 14, further comprising sharing a temperature policy with the chassis controller of maintaining the threshold temperature of the air volume of the chassis within a threshold temperature range by adjusting an air flow of the air mover.

21. The method of claim 20, further comprising receiving the temperature policy from the chassis controller.

22. The method of claim 14, further comprising:

monitoring temperature signals of the one or more temperature sensors;

taking control of the air mover when a temperature of the air volume of the chassis is outside a threshold temperature range;

determining a target air flow rate based on the one or more temperature signals to maintain the threshold temperature of the air volume of the chassis; and

adjusting an air flow of the air mover to move air at the target air flow rate.

23. The method of claim 22, further comprising relinquishing control of the air mover to the chassis controller after:

receiving a heartbeat signal from the chassis controller or periodically receiving heartbeat signals for a resume threshold period of time from the chassis controller; and

the temperature of the air volume of the chassis is within the threshold temperature range.