Heat Pipe Heat Sink Assemblies

Typical Application for Heat Pipe Heat Sinks

Laptop computers, telecommunications racks, etc... where local room for a heat sink is limited.  Also used to help concentrate or disperse thermal power density.

Closed evaporator-condenser system

• Sealed hollow tube

• Capillary structure or wick

• Thermal dynamic working fluid

How does the heat pipe heat sink work?

• Heat is applied at one end.

• Fluid in the wick is evaporated into the hollow center of the heat pipe.

• The vapor moves towards the cooler end of the pipe.

• The heat is dissipated out of the cool end and vapor is condensed back to a liquid into the wick.

• The liquid then flows back towards the heat source, creating a fluid flow pattern.

More heat pipe heat sink information:

• The heat carrying capacity of a heat pipe is directly proportional to the tube diameter.

   

• Typical heat pipe sizes range from .25" to 1.00" O.D. and will carry 100W to 1000W respectively.

   

• Length of the heat pipe, type of liquid used, wick material and the number of bends in the tube relate directly to the overall temperature rise of the heat pipe system.

  • Typical heat pipe liquids are water and methanol alcohol.

   

• For most cases the heat pipe has to be oriented in such a way that gravity will work with the system.

  • In most cases, heat source must be lower than the cold source.

  • However, there are variations which allow flexibility of orientation.

   

• Temperature Limits

  • The heat pipe can work at temperatures as low as -40ºC, but with only a fraction of the performance at 0ºC (depending on the liquid used).

  • Upper temperature limits of the heat pipe are in the average of 60ºC to 80ºC, again depending on the fluid used.

• Heat Removal (Cooling Source)

  • Extrusion Profiles, bonded fins, folded fins, etc.