Catalytic flameless combustion apparatus with extremely low pollutant emission and combustion method

A catalytic flameless combustion apparatus, comprising:

• a first housing having an upper end and a lower end closed by a plate, wherein at least one combustion-supporting gas inlet and at least one fuel inlet are disposed about the lower end of the first housing;
• a gas premixer disposed inside the first housing above the combustion-supporting gas inlet and the fuel inlet;
• a combustion plate disposed inside the first housing above the gas premixer;
• wherein a space between the lower end of the first housing and the combustion plate defines a gas premixing cavity, and the gas premixer resides in the gas premixing cavity;
• an igniter disposed inside the first housing above the combustion plate;
• a gas deflector having a tubular body with a lower opening and an upper opening;
• a second housing that defines a flameless combustion cavity and has a single opening opposed to the upper opening of the gas deflector;
• and
• a catalyst disposed inside the second housing,
• wherein the lower opening of the gas deflector is connected to the upper end of the first housing, and
• wherein the upper opening of the gas deflector is flush with the single opening in the second housing or extends into the flameless combustion cavity through the single opening in the second housing.