Heat Dissipation from ACB Toes

20170117103

15/299896

October 21, 2016

A heat dissipation apparatus, system and method for an air circuit breaker (ACB) switchgear has at least one pair of primary contact toes constructed and arranged to connect to a terminal of the circuit breaker. A bus bar joint is connected to the primary contact toes. The heat dissipation apparatus comprises an evaporator clamped to the primary contact toes. A condenser is located at a higher elevation than the evaporator and at least two electrically isolating pipes fluidly connect the evaporator with the condenser. A dielectric fluid in the evaporator can be heated to a vapour state, with one of the pipes transferring the vapour to the condenser and the second pipe returning the condensed dielectric fluid back to the evaporator for cooling the at least one pair of primary contact toes.

1. A heat dissipation apparatus for an air circuit breaker (ACB) switchgear having at least one pair of primary contact toes constructed and arranged to connect to a terminal of the circuit breaker, with a bus bar joint being connected to the primary contact toes, the heat dissipation apparatus comprising: an evaporator constructed and arranged to be clamped to the primary contact toes, a condenser located at a higher elevation than the evaporator, at least two electrically isolating pipes fluidly connecting the evaporator with the condenser, and a dielectric fluid in the evaporator adapted to be heated to a vapour state, with one of the pipes being constructed and arranged to transfer the vapour to the condenser and the second pipe being arranged to return the condensed dielectric fluid back to the evaporator for cooling the at least one pair of primary contact toes.

2. A heat dissipation apparatus as claimed in claim 1, wherein the condenser includes a plurality of fins in spaced relation, with the fins being arranged to transfer heat from the condenser to surrounding air by natural convection.

3. A heat dissipation apparatus as claimed in claim 2, wherein the fins of the condenser are metal and disposed substantially parallel to one another.

4. A heat dissipation apparatus as claimed in claim 1, in which the condenser is generally flat and includes a tubular arrangement of an elongate pipe formed into a plurality of U-shaped formations arranged to provide a thermosyphon effect for the efficient cooling of the dielectric fluid in the condenser.

5. A heat dissipation apparatus as claimed in claim 1, in which the evaporator is manufactured from copper or aluminum and has an internal fluid path for the dielectric fluid.

6. A heat dissipation apparatus as claimed in claim 5, in which the evaporator is clamped to the primary contact toes by means of at least one nut and bolt extending through an orifice in the evaporator.

7. A method of dissipating heat from an air circuit breaker (ACB) switchgear having at least one primary pair of contact toes constructed and arranged to connect to the terminal of a circuit breaker, with a bus bar joint being connected to the primary contact toes, the method comprising the steps of: clamping an evaporator to the primary contact toes, providing a condenser located at a higher elevation than the evaporator; providing at least two electrically isolating pipes fluidly connecting the evaporator with the condenser, and providing a dielectric fluid in the evaporator; and transferring heat from the primary contact toes to the working fluid to cause the dielectric fluid to evaporate in the evaporator with the evaporated vapour being delivered to the condenser via one of the pipes and returning the dielectric fluid that condenses in the condenser back to the evaporator via the second pipe.

8. A method of dissipating heat from an air circuit breaker (ACB) switchgear as claimed in claim 7, in which the condenser includes a plurality of fins in spaced relation, with the fins being arranged to transfer heat from the condenser to surrounding air by natural convention.

9. A method for dissipating heat from an air circuit breaker (ACB) switchgear as claimed in claim 8, in which the fins of the condenser are metal and disposed substantially parallel to one another.

10. A method of dissipating heat from an air circuit breaker (ACB) switchgear as claimed in claim 7, in which the air condenser is generally flat and includes a tubular arrangement of an elongate pipe formed into a plurality of U-shaped formations arranged to provide a thermosyphon effect for the efficient cooling of the dielectric fluid in the condenser.

11. A method of dissipating heat from an air circuit breaker (ACB) switchgear as claimed in claim 7, the evaporator is manufactured from copper or aluminum and has an internal fluid path for the dielectric fluid.

12. A method of dissipating heat as claimed in claim 11, characterized by clamping the evaporator to the primary contact toes by means of at least one nut and bolt extending through an orifice in the evaporator.

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edspap.20170117103