Process for operating a heater that can be operated with hydrocarbon fuel

A heater for a vehicle, the heater comprising:

• a precombustion chamber;
• a fuel supply which supplies hydrocarbon fuel to the precombustion chamber;
• a primary combustion air supply which supplies combustion air to the precombustion chamber;
• a catalyst arrangement disposed downstream of the precombustion chamber for receiving precombustion products from the precombustion chamber and for producing a gas containing hydrogen and carbon monoxide by means of partial catalytic oxidation;
• a main combustion chamber downstream of the catalyst arrangement for receiving the gas containing hydrogen and carbon monoxide from the catalyst arrangement;
• and
• a secondary combustion air supply which supplies combustion air to the main combustion chamber, wherein:
• at least one of the primary combustion air supply and the fuel supply provide a substoichiometric air/fuel mixture to the precombustion chamber for a combustion operation.

A vehicle heater comprising:

• a precombustion chamber;
• a fuel supply which supplies hydrocarbon fuel to the precombustion chamber;
• a primary combustion air supply which supplies combustion air to the precombustion chamber, the primary combustion air supply and the fuel supply cooperating to provide a substoichiometric air/fuel mixture to the precombustion chamber for a cold flame combustion in the precombustion chamber to form precombustion products;
• a catalyst arrangement disposed downstream of the precombustion chamber for receiving the precombustion products from the precombustion chamber and performing a partial catalytic oxidation, of the supplied precombustion products, to produce a gas containing hydrogen and carbon monoxide;
• a main combustion chamber downstream of the catalyst arrangement for receiving the gas containing hydrogen and carbon monoxide from the catalyst arrangement;
• and
• a secondary combustion air supply which supplies combustion air to the main combustion chamber for burning a mixture of the hydrogen and the carbon monoxide and the supplied air in the main combustion chamber.