Thermal diode

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The term thermal diode is sometimes used to describe a (possibly non-electrical) device which causes heat to flow preferentially in one direction. Or, the term may be used to describe an electrical (semiconductor) diode in reference to a thermal effect or function. Or the term may be used to describe both situations, where an electrical diode is used as a heat-pump or thermoelectric cooler.

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[edit] One-way heat-flow

A thermal diode can be:

  • a heat engine which converts a heat difference directly into electric power.
  • a heat engine working backwards as a refrigerator, such as a Stirling engine
  • a type of Heat pipe which will only allow heat to flow from the evaporator to the condenser. When the condenser is hotter than the evaporator, the coolant in the heat pipe condenses in a reservoir at the evaporator end. This reservoir does not have a capillary connection with the condenser, preventing the liquid from returning to the condenser. During normal heat pipe operation, when the evaporator and reservoir become hotter than the condenser, the reservoir is emptied by evaporation, and heat is transferred to the condenser.

[edit] Electrical diode thermal effect or function

  • a sensor device embedded on microprocessors used to monitor the temperature of the processor's die.

[edit] Thermoelectric heat-pump or cooler

There are two types. One uses semiconductor, or less efficient metal, i.e. thermocouples, working on the principles of the Peltier-Seebeck effect. The other relies on vacuum tubes and the principles of thermionic emission.

[edit] Peltier devices

[edit] External links


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