Microchannel heat exchanger with micro-encapsulated phase change material for high flux cooling

• US 20060231233A1
• Filed: 04/14/2005
• Published: 10/19/2006
• Est. Priority Date: 04/14/2005
• Status: Active Grant

• Current Assignee: Mohammed Mehdi Farid, Said Al-Hallaj
• Original Assignee: Mohammed Mehdi Farid, Said Al-Hallaj
• Inventors: Farid, Mohammed Mehdi, Al-Hallaj, Said
• Granted Patent: US 8,109,324 B2
• Time in Patent Office: Days
• US Class Current: 165/10
• CPC Class Codes: F28D 15/0266 with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers F28D15/043 takes precedence
• CPC Class Codes: F28D 20/023 the latent heat storage material being enclosed in granular particles or dispersed in a porous, fibrous or cellular structure
• CPC Class Codes: F28F 2260/02 having microchannels
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y02E 60/14 Thermal energy storage

Abstract

A microchannel cooler containing a slurry having a particulate liquid/solid phase change material is provided balancing the interdependent factors of microencapsulated particle size with microchannel size and shape and flow conditions for the removal of high heat flux with low space and low power requirements.

Claims

1. A microchannel heat exchanger for a heat generating component, comprising:

a slurry containing a particulate liquid/solid phase change material operable to melt in a heat range required for cooling the heat generating component;

a heat exchanger located or locatable in proximity to the heat generating component to remove heat therefrom, the heat exchanger having a series of microchannels for passage of the liquid slurry;

the slurry being within the microchannels of the heat exchanger; and

a pump for moving the liquid slurry at flow rate through the heat exchanger.

2. The microchannel heat exchanger according to claim 1, further comprising:

the microchannels having a non-linear path designed to increase flow disturbance over that of a straight channel.

3. The microchannel heat exchanger according to claim 1, further comprising:

the slurry being a mixture of about 30% phase change material and about 70% water or other liquid of equal or higher specific heat, by mass.

4. The microchannel heat exchanger according to claim 1, further comprising:

the phase change material being microencapsulated.

5. The microchannel heat exchanger according to claim 4, further comprising:

the microencapsulated phase change material being of a diameter in the range of about 5 percent to about 20 percent of the microchannel width.

6. The microchannel heat exchanger according to claim 1, further comprising:

the melting point of the PCM being from about 20°

C. to about 50°

C.

7. The microchannel heat exchanger according to claim 1, further comprising:

a secondary heat exchanger for transfer of heat to ambient surroundings of the heat generating component and the heat exchanger.

8. The microchannel heat exchanger according to claim 1, further comprising:

the heat exchanger having an inlet and an outlet, with the temperature difference of the slurry between the inlet and the outlet being about 5°

C. to about 20°

C.

9. The microchannel heat exchanger according to claim 1 with a heat flux capacity of at least 100 W/cm².

10. The microchannel heat exchanger according to claim 1 with a heat flux capacity of between about 100 W/cm and 200 W/cm².

11. The microchannel heat exchanger according to claim 1, further comprising:

the microchannels proportionately having a width of about 100 microns, a length of about 1 centimeter, and a height of 500 microns.

12. The microchannel heat exchanger according to claim 1, further comprising:

the microchannels proportionately having a width of about 400 microns, a length of about 2 centimeters, and a height of 1 cm.

13. The microchannel heat exchanger according to claim 1, wherein the flow rate has a mean velocity of about 0.50 to about 0.64 meters/second.

14. The microchannel heat exchanger according to claim 1, further comprising:

the microchannels having an aspect ratio of height to width of at least 5;

1.

15. The microchannel heat exchanger according to claim 1, further comprising:

a wall thickness between channels of between about 100 to about 200 microns.

16. The microchannel heat exchanger according to claim 1, wherein the pressure drop is about 1.5 to about 6.86 kPa for a laminar flow within one microchannel.

17. The microchannel heat exchanger according to claim 1, wherein the pumping power requirement is about 6.1 to about 8.41 mW.

18. The microchannel heat exchanger according to claim 1, further comprising the heat exchanger being located in proximity to the heat generating component to remove heat therefrom.

19. The microchannel heat exchanger according to claim 18, further comprising the heat exchanger being integrally formed with the heat generating component to remove heat therefrom.

20. The microchannel heat exchanger according to claim 1 wherein the heat generating component is one of an integrated circuit, a computer processor, a battery, a fuel cell, or a printed circuit board.