Method and apparatus for cooling bus bars

• US 6,574,094 B1
• Filed: 04/11/2002
• Issued: 06/03/2003
• Est. Priority Date: 04/11/2002
• Status: Expired due to Fees

• Current Assignee: General Dynamics Land Systems Incorporated (General Dynamics Corporation)
• Original Assignee: General Dynamics Land Systems Incorporated (General Dynamics Corporation)
• Inventors: Morrow, Ernest J., Sellers, Sally M., Knudsen, Gary D.
• Primary Examiner(s): THOMPSON, GREGORY D
• Application Number:
  US10/120,811
• Time in Patent Office: 418 Days
• Field of Search: 165/80.4, 165/80.3, 165/104.33, 165/908, 174/15-- 1, 174/16-- 1, 174/71.B, 174/149.B, 174/72.B, 174/88.B, 174/99.B, 174/133.B, 361/611, 361/613, 361/624, 361/636-640, 361/648-650, 361/688, 361/690, 361/698-704, 361/715, 361/775, 361/831, 622/592
• US Class Current: 361/676
• CPC Class Codes: F28D 5/00 Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, using the cooling effect of natural or forced evaporation
• CPC Class Codes: H02G 5/10 Cooling
• CPC Class Codes: Y10S 165/908 Fluid jets

Abstract

A method for cooling bus bars 12,14 in order to increase their current-carrying capacity while saving space and weight. The method comprises the steps of providing a housing having an interior wall; locating a distribution manifold 20 within the housing, the distribution manifold comprising a hollow bus bar 12,14; communicating to the manifold a supply of an evaporative coolant 18, 18′; and delivering the coolant 18, 18′ outwardly under pressure so that upon exiting the manifold 20, the coolant 18, 18′ undergoes a phase change from the liquid to the vapor state. Heat is extracted from the manifold 20 at least as quickly as heat is generated by the flow of current. The extraction of heat by the flow of coolant 18, 18′ and evaporation maintains or lowers the temperature of the bus bar and enables a given size of bus bar to carry more current without a significant rise in temperature. The invention also includes an apparatus 10 for cooling bus bars 12,14 in an electrical circuit. The bus bars 12,14 are mounted in close proximity with each other, thereby saving space and weight in the electrical circuit and providing good electrical noise immunity.

Claims

1. A method for cooling bus bars in order to increase their current-carrying capacity while saving space and weight, comprising the steps of:

providing a housing having an interior wall;

locating a distribution manifold within the housing, the distribution manifold comprising a pair of hollow bus bars;

communicating to the manifold a supply of an evaporative coolant; and

delivering the coolant under pressure so that upon exiting the manifold, the coolant impacts an external surface of one or more bus bars adjacent to the manifold or other adjacent surfaces, so that at least a portion of the coolant undergoes a phase change from the liquid to the vapor state, and heat is extracted from the manifold and at least some of the one or more bus bars adjacent to the manifold at least as quickly as heat is generated by the flow of current, the extraction of heat by the flow of coolant and evaporation thereby maintaining or lowering the temperature of the bus bars and enabling a given size of bus bar to carry more current without a significant rise in temperature.

2. The method of claim 1, further comprising the step of:

allowing at least some of the coolant following evaporation to condense upon an interior wall of the housing.

3. The method of claim 1, further comprising the step of:

providing an external finned surface upon the housing, thereby allowing heat to be transferred by convection therefrom and maintaining the temperature of the housing lower than the boiling point of the coolant.

4. The method of claim 3, further comprising the step of:

communicating a return flow path for the condensed coolant from at least one of the interior walls of the housing to the distribution manifold.

5. An apparatus for cooling bus bars in an electrical circuit, comprising:

a flange;

a plurality of bus bars mounted to the flange, an enclosed space between an adjacent two of the plurality of bus bars defining a distribution manifold through which an evaporative coolant flows, so that upon exiting the manifold, the coolant impacts an external surface of one or more bus bars adjacent to the plurality of bus bars or other adjacent surfaces, so that at least a portion of the coolant undergoes a phase change from the liquid to the vapor state, and the heat is extracted from the plurality of bus bars mounted to the flange and the one or more bus bars adjacent thereto and or other adjacent surfaces at least as quickly as heat is generated by the flow of current, the extraction of heat by the flow of coolant and by evaporation thereby maintaining or lowering the temperature of the bus bars and enabling a given size of bus bar to carry more current without a significant rise in temperature,

the plurality of bus bars and the one or more bus bars or other adjacent surfaces being mounted in close proximity with each other, thereby saving space and weight in the electrical circuit and providing good electrical noise immunity.

6. The apparatus of claim 5, further comprising:

one or more spacers extending between adjacent bus bars in the plurality of bus bars mounted to the flange.

7. The apparatus of claim 5, further comprising:

one or more nozzles associated with one or more of the plurality of bus bars, some of the one or more nozzles being configured so that the evaporative coolant exiting from a given bus bar is directed towards a facing bus bar or other electrical components in the apparatus.

8. The apparatus of claim 7, wherein some of the one or more nozzles are configured so that the evaporative coolant from a given bus bar exits substantially perpendicularly to a cooling surface of the given bus bar, thereby predominantly cooling adjacent components.

9. The apparatus of claim 7, wherein some of the one or more nozzles are configured so that the evaporative coolant exiting from a given bus bar exits substantially parallel to a cooling surface of the given bus bar, thereby predominantly cooling that bus bar.