Off-axis cooling of rotating devices using a crank-shaped heat pipe

• US 7,168,480 B2
• Filed: 04/29/2004
• Issued: 01/30/2007
• Est. Priority Date: 04/29/2004
• Status: Expired due to Fees

• Current Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Original Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Inventors: Prenger, F. Coyne, Jankowski, Todd A., Waynert, Joseph A.
• Primary Examiner(s): Walberg; Teresa J.
• Application Number:
  US10/835,897
• Publication Number:
  US 20050241807A1
• Time in Patent Office: 1,006 Days
• Field of Search: 165/104.26, 165/104.33, 165/104.21, 165/185, 165/80.4, 361/700, 174/15.2
• US Class Current: 165/104.26
• CPC Class Codes: F28D 15/0208 using moving tubes
• CPC Class Codes: F28D 15/046 characterised by the material or the construction of the capillary structure
• CPC Class Codes: H02K 9/225 Heat pipes

Abstract

The present invention is a crank-shaped heat pipe for cooling rotating machinery and a corresponding method of manufacture. The crank-shaped heat pipe comprises a sealed cylindrical tube with an enclosed inner wick structure. The crank-shaped heat pipe includes a condenser section, an adiabatic section, and an evaporator section. The crank-shape is defined by a first curve and a second curve existing in the evaporator section or the adiabatic section of the heat pipe. A working fluid within the heat pipe provides the heat transfer mechanism.

Claims

1. A crank-shaped heat pipe for cooling rotating machinery, comprising:

(a) a cylindrical tube defining an inner wall, a condenser section, an evaporator section, and an adiabatic section,

(b) a wick structure within said cylindrical tube,

(c) a working fluid within said cylindrical tube for use as a heat transfer mechanism, and

(d) said evaporator section or said adiabatic section defining a first curve and a second curve, said first curve and said second curve ranging from about 75 degrees to about 85 degrees, where said first and second curves reduce said working fluid instability and increase said heat transfer capability of said heat pipe, said wick structure including a first mesh screen and spacer wires, said first mesh screen separated from said inner wall by said spacer wires.

2. The heat pipe of claim 1, where said wick structure further comprises a second mesh screen, said second mesh screen in contact with said inner wall and said first mesh screen separated from said second mesh screen by said spacer wires.

3. The beat pipe of claim 1, where said working fluid is selected from the group consisting of:

helium, hydrogen, pentane, and potassium.

4. The heat pipe of claim 1, where said first and second curves define a small radius and a large radius, where said small and large radii are a minimum of 2 inches.

5. The heat pipe of claim 1, where a radial distance between said condenser section and said evaporator section ranges from 0 to 16 inches.

6. The heat pipe of claim 1 where said cylindrical tube comprises metals selected from the group consisting of copper, stainless steel, and low-carbon steels.

7. The heat pipe of claim 1, where said wick structure comprises a plug that seals said evaporator section to allow full capillary pressure to develop during stationary applications.

8. A method of making a crank-shaped heat pipe with an evaporator section, an adiabatic section, and a condenser section, comprising:

(a) forming and inserting a cylindrical wick structure into a cylindrical tube, said wick structure including a first mesh screen and spacer wires, said first mesh screen separated from said inner wall by said spacer wires,

(b) forming a first curve and a second curve in said cylindrical tube, said first curve and said second curve ranging from about 75 degrees to about 85 degrees,

(c) brazing caps onto both ends of said crank-shape heat pipe,

(d) evacuating resident gases from within said crank-shape heat pipe,

(e) charging a working fluid into said crank-shape beat pipe, and

(f) sealing said crank-shape heat pipe.

9. The method of making a crank-shaped heat pipe in claim 8, where forming and inserting said cylindrical wick structure comprises:

(a) cutting a section of a screen to a length of said cylindrical tube,

(b) spot-welding spacer wires to said screen,

(c) rolling said section of said screen two revolutions or more to form a cylindrical wick structure, and

(d) inserting said cylindrical wick structure into said cylindrical tube.

10. The method of making a crank-shaped heat pipe in claim 8, where forming and inserting said cylindrical wick structure comprises:

(a) cutting a section of a screen to a length of said cylindrical tube,

(b) rolling said section of said screen two revolutions or more to form a screen cylinder,

(c) placing said screen cylinder into a spring sized to fit the length and diameter of said cylindrical tube to form said cylindrical wick structure, and

(d) inserting said cylindrical wick structure into said cylindrical tube.

11. The method of making a crank-shaped heat pipe in claim 8, where forming and inserting said cylindrical wick structure comprises:

(a) cutting a first section of screen and a second section of a screen to a length of said cylindrical tube,

(b) rolling said first section of screen two revolutions or more to form a first cylindrical wick,

(c) inserting said first cylindrical wick into said cylindrical tube,

(d) spot-welding spacer wires to said second section of said screen,

(e) rolling said second section of said screen two revolutions or more to form a second cylindrical wick, and

(f) placing said second cylindrical wick within said first cylindrical wick to form said cylindrical structure within said cylindrical tube.

12. The method of making a crank-shaped heat pipe in claim 8, where said first curve and said second curve are formed with a minimum radii of 2 inches.

13. The method of making a crank-shaped heat pipe in claim 8, where forming and inserting said cylindrical wick structure further includes sealing said wick structure with a plug on said evaporator section.