DEMAND-BASED CHARGING OF A HEAT PIPE

• US 20170102189A1
• Filed: 02/16/2016
• Published: 04/13/2017
• Est. Priority Date: 10/13/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Anderl, William J., Elison, Bret P., Mann, Phillip V., Sinha, Arvind K.
• Granted Patent: US 10,295,270 B2
• Time in Patent Office: Days
• CPC Class Codes: F16K 31/002 actuated by temperature variation thermo-electric F16K31/025
• CPC Class Codes: F28D 15/0275 Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
• CPC Class Codes: F28D 15/0283 Means for filling or sealing heat pipes
• CPC Class Codes: F28D 15/06 Control arrangements therefor
• CPC Class Codes: F28D 2015/0216 having particular orientation, e.g. slanted, or being orientation-independent
• CPC Class Codes: F28F 3/02 Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations F28F3/08 takes precedence

Abstract

A heat pipe includes one or more reservoirs of liquid that are closed at lower temperatures and open at higher temperatures. The opening of the reservoirs at higher temperatures caused by higher power levels dynamically increases the amount of liquid in the heat pipe, which increases performance of the heat pipe at higher power levels. As the heat pipe cools, the liquid condenses and flows back into the reservoirs. As the heat pipe continues to cool, the reservoirs close. The result is a heat pipe that is more efficient at lower power levels and still maintains high efficiency at higher power levels due to the demand-based charging of the liquid based on temperature.

Claims

1. A method for transferring heat from a heat source using a heat pipe, the method comprising:

thermally coupling the heat pipe to the heat source, the heat pipe comprising;

an interface for thermally coupling the heat source to the heat pipe;

a substantially horizontal portion overlying the interface;

a reservoir in a lower portion of the substantially horizontal portion that contains liquid; and

a temperature-actuated valve overlying the reservoir, wherein the temperature-actuated valve seals the liquid in the reservoir when the temperature is below an actuation temperature and unseals the liquid in the reservoir when the temperature is above the actuation temperature;

the heat source heating the heat pipe, causing the temperature in the substantially horizontal portion to rise to the actuation temperature;

in response to reaching the actuation temperature, the temperature-actuated valve unseals the reservoir, allowing the liquid to pass into the substantially horizontal portion; and

as temperature in the substantially horizontal portion falls, the liquid condenses and flows by the force of gravity through the temperature-actuated valve into the reservoir, and when the temperature falls to the actuation temperature, the temperature-actuated valve seals the liquid in the reservoir.

2. A method for manufacturing a heat pipe comprising:

providing a reservoir in a heat pipe;

designing a temperature-actuated valve to open at a specified temperature;

filling the reservoir with liquid;

installing the temperature-actuated valve to cover the reservoir;

charging the heat pipe with liquid; and

sealing the heat pipe.

3. A method for manufacturing a heat sink comprising:

constructing a heat pipe comprising;

an interface for thermally coupling an integrated circuit to the heat pipe;

a substantially horizontal portion that overlies the interface and contains a first quantity of a liquid;

two vertical members connected with the substantially horizontal portion to form a U-shape;

first and second reservoirs in a lower portion of the substantially horizontal portion, wherein each of the first and second reservoirs contains liquid and at least partially underlies one of the two vertical members;

a first bi-metal valve overlying the first reservoir, the first bi-metal valve sealing the liquid in the first reservoir when the temperature is below a first actuation temperature and unsealing the liquid in the first reservoir when the temperature is above the first actuation temperature; and

a second bi-metal valve overlying the second reservoir, the second bi-metal valve sealing the liquid in the second reservoir when the temperature is below a second actuation temperature and unsealing the liquid in the second reservoir when the temperature is above the second actuation temperature; and

thermally coupling a plurality of thermally-conductive fins to the heat pipe.