Dual Port Heat Pipe Structure For Switchgear

Abstract

A cooling apparatus is provided for a switchgear. The switchgear has an enclosure having a plurality of compartments. The cooling apparatus includes at least one evaporator constructed and arranged to be mounted in one of the compartments. The evaporator includes an evaporator plate having surfaces defining passage structure therein, and a cover plate covering a portion of the evaporator plate to seal the passage structure. A condenser is located at a higher elevation than the evaporator. First and second conduits fluidly connect the evaporator plate with the condenser. A working fluid is in the passage structure so as to be heated to a vapor state at the evaporator, with the first fluid conduit transferring the vapor to the condenser and with the second fluid conduit passively returning condensed working fluid back to the passage structure of the evaporator.

What is claimed is: 
     
         1 . A cooling apparatus for a switchgear, the switchgear having an enclosure having a plurality of compartments including a circuit breaker compartment containing at least one circuit breaker, a main bus compartment housing a main bus that is connected with the circuit breaker, and a cable compartment, the cooling apparatus comprising:
 at least one evaporator constructed and arranged to be mounted in one of the compartments, the at least one evaporator comprising:
 an evaporator plate having surfaces defining passage structure therein, and 
 a cover plate covering a portion of the evaporator plate to seal the passage structure, 
   a condenser located at a higher elevation than the evaporator,   a first fluid conduit fluidly connecting the evaporator plate with the condenser,   a second fluid conduit, separate from the first fluid conduit, fluidly connecting the evaporator plate with the condenser, and   a working fluid in the passage structure so as to be heated to a vapor state at the evaporator, with the first fluid conduit being constructed and arranged to transfer the vapor to the condenser and with the second fluid conduit being constructed and arranged to passively return condensed working fluid back to the passage structure of the evaporator.   
     
     
         2 . The cooling apparatus of  claim 1 , wherein the evaporator plate has a top portion and a bottom portion, the first fluid conduit being coupled to the top portion and the second fluid conduit being coupled to the bottom portion. 
     
     
         3 . The cooling apparatus of  claim 2 , wherein the passage structure extends from the bottom portion to the top portion of the evaporator plate. 
     
     
         4 . The cooling apparatus of  claim 3 , wherein the passage structure is defined by surfaces so as to form a continuous, serpentine passage between the bottom portion and the top portion of the evaporator plate so that the working fluid must change direction multiple times in the passage prior to reaching the first conduit. 
     
     
         5 . The cooling apparatus of  claim 1 , wherein the evaporator plate and the cover plate are each composed of copper. 
     
     
         6 . The cooling apparatus of  claim 1 , wherein the working fluid is selected from the group consisting of hydrofluorocarbon, fluoroketone, and hydrofluoroether refrigerants, and any mixtures thereof. 
     
     
         7 . The cooling apparatus of  claim 1 , in combination with the switchgear, wherein the at least one evaporator is mounted in the main bus compartment. 
     
     
         8 . The cooling apparatus of  claim 7 , where a plurality of evaporators are connected with the condenser, each evaporator being adjacent to an associated bus bar of the main bus. 
     
     
         9 . The combination of  claim 7 , wherein the condenser is mounted to the enclosure. 
     
     
         10 . The cooling apparatus of  claim 1 , wherein the condenser is constructed and arranged to exchange heat with ambient air to cause the vapor to condense to liquid working fluid. 
     
     
         11 . A method of cooling a switchgear having an enclosure having a plurality of compartments including a circuit breaker compartment containing at least one circuit breaker, a main bus compartment housing a main bus that is connected with the circuit breaker, and a cable compartment, the method comprising the steps of:
 providing at least one evaporator comprising an evaporator plate having surfaces defining passage structure therein, and a cover plate covering a portion of the evaporator plate to seal the passage structure,   mounting the evaporator in one of the compartments,   providing a condenser at a higher elevation than the evaporator, with a first and second fluid conduits fluidly connecting the evaporator with the condenser, and with a working fluid in the evaporator,   permitting heat transfer from the evaporator to the working fluid to cause the working fluid to convert form a liquid to a vapor state, with the vapor being delivered to the condenser via the first fluid conduit, and   passively returning the working fluid that condenses in the condenser to the evaporator via the second fluid conduit.   
     
     
         12 . The method of  claim 11 , wherein the step of providing the evaporator includes providing the evaporator plate to have a top portion and a bottom portion, the first fluid conduit being coupled to the top portion and the second fluid conduit being coupled to the bottom portion. 
     
     
         13 . The method of  claim 12 , wherein the passage structure extends from the bottom portion to the top portion of the evaporator plate. 
     
     
         14 . The method of  claim 13 , wherein the passage structure is defined by surfaces so as to form a continuous, serpentine passage between the bottom portion and the top portion of the evaporator plate so that the working fluid must change direction multiple times in the passage prior to reaching the first conduit. 
     
     
         15 . The method of  claim 11 , wherein the evaporator plate and the cover plate are provided from copper. 
     
     
         16 . The method of  claim 11 , wherein the working fluid is selected from the group consisting of hydrofluorocarbon, fluoroketone, and hydrofluoroether refrigerants, and any mixtures thereof. 
     
     
         17 . The method of  claim 11 , wherein the evaporator is mounted in the main bus compartment. 
     
     
         18 . The method of  claim 17 , wherein a plurality of evaporators is provided and each evaporator is mounted adjacent to an associated bus bar of the main bus. 
     
     
         19 . The method of  claim 1 , wherein the condenser is mounted on the enclosure.