Valved heat pipe and adaptive cooling system including the same

Abstract

A valved heat pipe and an adaptive circuit cooling system using it are disclosed. The valved heat pipe includes a sealed tube, liquid in the tube, and at least one valve in the tube. This valve operates as a function of temperature to selectively obstruct circulation of the liquid from one end of the tube to the other. The adaptive cooling system includes heat generating equipment, e.g., electronic circuitry such as radio frequency transmitters and/or recievers, a heat sink and such a valved heat pipe that thermally connects the circuitry to the heat sink.

What is claimed:  
     
         1 . An adaptive cooling system comprising: 
 heat generating equipment;    a heat sink; and    a heat pipe thermally connecting said heat generating equipment to said heat sink;    wherein said heat pipe includes at least one valve that operates as a function of temperature.    
     
     
         2 . The cooling system of    claim 1   , wherein said at least one valve is open or closed based upon a temperature to which said at least one valve is exposed.  
     
     
         3 . The cooling system of    claim 2   , wherein said at least one valve is a bimetallic device.  
     
     
         4 . The cooling system of    claim 1   , further comprising: 
 a temperature sensor; and    a controller for receiving a signal indicative of temperature from said temperature sensor;    wherein said at least one valve is actuated by at least one control signal from said controller, respectively; and    wherein said controller is operable to cause said at least one valve to open when said temperature signal is greater than or equal to a corresponding reference value, respectively.    
     
     
         5 . The cooling system of    claim 4   , wherein said at least one control signal is electrical and said at least one valve is a solenoid valve.  
     
     
         6 . The cooling system of    claim 1   , further comprising a thermally conductive substrate, wherein said circuitry is mounted to said substrate and said heat pipe is thermally connected to said substrate such that heat from said circuitry is transferred to said heat pipe via said substrate.  
     
     
         7 . The cooling system of    claim 6   , wherein said substrate is metallic.  
     
     
         8 . An adaptive electronic circuit cooling system comprising: 
 electronic circuitry;    a heat sink; and    a heat pipe thermally connecting said circuitry to said heat sink;    wherein said heat pipe includes at least one valve that operates as a function of temperature.    
     
     
         9 . The cooling system of    claim 8   , wherein said at least one valve is open or closed based upon a temperature to which said at least one valve is exposed.  
     
     
         10 . The cooling system of    claim 9   , wherein said at least one valve is a bimetallic device.  
     
     
         11 . The cooling system of    claim 8   , further comprising: 
 a temperature sensor; and    a controller for receiving a signal indicative of temperature from said temperature sensor;    wherein said at least one valve is actuated by at least one control signal from said controller, respectively; and    wherein said controller is operable to cause said at least one valve to open when said temperature signal is greater than or equal to a corresponding reference value, respectively.    
     
     
         12 . The cooling system of    claim 11   , wherein said at least one control signal is electrical and said at least one valve is a solenoid valve.  
     
     
         13 . The cooling system of    claim 8   , further comprising a thermally conductive substrate, wherein said circuitry is mounted to said substrate and said heat pipe is thermally connected to said substrate such that heat from said circuitry is transferred to said heat pipe via said substrate.  
     
     
         14 . The cooling system of    claim 13   , wherein said substrate is metallic.  
     
     
         15 . A valved heat pipe comprising: 
 a sealed tube;    liquid in said tube; and    at least one valve in said tube operates as a function of temperature to selectively obstruct circulation of said liquid from one end of said tube to the other.    
     
     
         16 . The heat pipe of    claim 15   , wherein said at least one valve is open or closed based upon a temperature to which said at least one valve is exposed.  
     
     
         17 . The heat pipe of    claim 16   , wherein said at least one valve is a bimetallic device.  
     
     
         18 . The heat pipe of    claim 8   , wherein said at least one valve is actuated by a control signal from a controller.  
     
     
         19 . The heat pipe of    claim 18   , wherein said control signal is electrical and said at least one valve is a solenoid valve.