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Carbon or Graphite Foam Heating Element for Regulating Engine Fluids

Oak Ridge National Laboratory

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Technology Marketing SummaryAutomotive engines need to run hotter to meet requirements for better fuel economy and lower emissions, but devices to keep engine fluids from becoming too hot can add weight, cost, and complexity to engine designs. ORNL researchers developed a graphite foam heating element that can eliminate the need for a separate cooler for oil and other fluids. The invention also has the potential to cool known engine hot spots, which can increase the life of the engine. DescriptionThe foam has good thermal conductivity, thermal diffusivity, electrical resistivity, and density characteristics—all traits that make for an excellent thermal regulator. These features also permit the foam to function as both a heat exchanger and a heating element.

The invention’s high electrical resistivity ensures that when the foam is submersed in a fluid such as motor oil, the fluid can be heated by an electrical circuit. At engine startup, preheating the oil reduces emissions and engine wear. The device can both heat the engine oil at start-up, and then later cool it.
  • Functions as both a preheater and a passive heat exchanger
  • May be disposable and/or easily retrofitted to existing engines
  • Preheats oil (or other fluid) to reduce emissions at start-up
  • Regulates temperature during steady-state operation
  • Permits the use of lighter oils for improved fuel economy
Applications and Industries
  • All types of work and passenger vehicles
  • Large stationary motors (such as mining equipment)
More InformationLead Inventor:
Ronald D. Ott
Materials Science and Technology Division
Oak Ridge National Laboratory
Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Patent 6,729,269
Carbon or graphite foam as a heating element and system thereof
A temperature regulator includes at least one electrically conductive carbon foam element. The foam element includes at least two locations adapted for receiving electrical connectors thereto for heating a fluid, such as engine oil. A combustion engine includes an engine block and at least one carbon foam element, the foam element extending into the engine block or disposed in thermal contact with at least one engine fluid.
Oak Ridge National Laboratory 05/04/2004
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated
UT-B ID 200000861DevelopmentAvailable10/20/201012/15/2010

Contact ORNL About This Technology

To: Alexander G. DeTrana<>