Loop heat pipe structure with low-profile evaporator

• US 9,052,147 B2
• Filed: 06/08/2011
• Issued: 06/09/2015
• Est. Priority Date: 04/29/2011
• Status: Active Grant

• Current Assignee: Asia Vital Components Company Limited
• Original Assignee: Asia Vital Components Company Limited
• Inventors: Xiang, Jun, Zhou, Xiao-Xiang
• Primary Examiner(s): Duong, Tho V
• Assistant Examiner(s): ISENSTADT, AARON S
• Application Number:
  US13/156,324
• Publication Number:
  US 20120273167A1
• Time in Patent Office: 1,462 Days
• Field of Search: 165/104.21, 165/104.22, 165/104.26, 165/168, 165/169, 165/104.19
• US Class Current: 1/1
• 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 15/0275 Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
• CPC Class Codes: F28D 15/046 characterised by the material or the construction of the capillary structure
• 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 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

Abstract

A loop heat pipe structure includes an evaporator and a first pipe. The evaporator has a first chamber, a first wick layer, and a bottom. The first wick layer is provided in the first chamber. The first pipe includes a first inlet and a first outlet communicably connected to the evaporator. The first inlet internally defines a second chamber communicable with the first wick layer. By providing the second chamber outside the evaporator, the evaporator can have a reduced overall height without creating very high vapor pressure in the evaporator, enabling the loop heat pipe structure to have upgraded heat dissipation efficiency.

Claims

1. A loop heat pipe structure, comprising:

an evaporator having a first chamber, a first wick layer, a bottom and a plurality of grooves;

the first chamber being a hollow chamber;

the first wick layer being provided only in the first chamber to thereby define a first main chamber and a first secondary chamber in the first chamber;

the first wick layer having a working fluid filled therein; and

the grooves being selectively provided on the bottom; and

wherein the first wick layer provided in the first main chamber directly contacts a top wall of said first main chamber; and

a first pipe having a first inlet portion and a first outlet;

wherein the first inlet portion is an enlarged pipe section having a wider and flatter configuration than the first outlet, thereby internally defining a second chamber and is extended through a wall of the evaporator to insert into and communicate with the first wick layer;

wherein the first outlet is not enlarged and is connected to another wall of the evaporator to communicate with the first secondary chamber; and

wherein the second chamber is internally provided with a second wick layer which communicates with the first wick layer.

2. The loop heat pipe structure as claimed in claim 1, wherein the evaporator includes a cover and a bottom plate together enclosing the first chamber;

the first wick layer being provided on the bottom plate to thereby define the first main chamber and the first secondary chamber in the first chamber; and

the grooves being selectively provided on the bottom plate of the evaporator.

3. The loop heat pipe structure as claimed in claim 1, wherein the evaporator further includes a working pipe.

4. The loop heat pipe structure as claimed in claim 1, wherein the first wick layer is selected from the group consisting of a sintered powder body, a net-like body, carbon fibers, and graphite.

5. The loop heat pipe structure as claimed in claim 1, wherein the second wick layer has an effective capillary radius larger than that of the first wick layer.

6. The loop heat pipe structure as claimed in claim 1, wherein the second wick layer has thermal conductivity lower than that of the first wick layer.

7. The loop heat pipe structure as claimed in claim 1, wherein the first pipe is extended through a plurality of radiating fins.

8. The loop heat pipe structure as claimed in claim 1, further comprising a second pipe having a second inlet portion and a second outlet;

wherein the second inlet portion is an enlarged pipe section having a wider and flatter configuration than the second outlet, thereby internally defining a third chamber and being connected to a wall of the evaporator to communicate with the first wick layer, and wherein the second outlet is not enlarged and is connected to another wall of the evaporator to communicate with the first secondary chamber.

9. The loop heat pipe structure as claimed in claim 8, wherein the third chamber is internally provided with a third wick layer.

10. The loop heat pipe structure as claimed in claim 1, wherein the second wick layer has permeability larger than that of the first wick layer.

11. The loop heat pipe structure as claimed in claim 9, wherein the third wick layer has permeability larger than that of the first wick layer.

12. The loop heat pipe structure as claimed in claim 1, wherein the first pipe is extended through a condensing device.

13. The loop heat pipe structure as claimed in claim 1, wherein the first pipe is extended through a water-cooled device.

14. The loop heat pipe structure as claimed in claim 8, wherein the second pipe is extended through a condensing device.

15. The loop heat pipe structure as claimed in claim 8, wherein the second pipe is extended through a water-cooled device.

16. The loop heat pipe structure as claimed in claim 1, further comprising a fourth wick layer provided to one side of the first wick layer.

17. The loop heat pipe structure as claimed in claim 1, wherein the first secondary chamber has a first end and an opposite second end;

the first end and the second end communicating with each other; and

the first secondary chamber being tapered from the second end toward the first end.