Patent ID: 6345495
Filing Date: 2002-02-12
Classification: F02C,F23C,F23D,F23R,Y02E

Abstract:
A gas turbine system for the utilization of a fuel gas comprising a mixture of air and at least one combustible gas to produce useful energy, wherein the concentration of air in the fuel gas is such that the fuel gas is below the lower flammability limit for the at least one combustible gas, the system comprising:a compression stage receiving the fuel gas and outputting compressed fuel gas, a combustor comprising a vessel having an inlet for the supply of the compressed fuel gas from the compression stage, a combustion zone, an array of hollow tubes having one end open to the supplied fuel gas and the other end open to the combustion zone, the tubes being spaced-apart so that the outside of the tubes form an exit path for combusted gas from the combustion zone passing to an outlet from the vessel, a portion of the heat of the combusted gas being transferred through walls of the tubes to the fuel gas within the tubes to preheat the fuel gas before entering the combustion zone, wherein the end of the tubes open to the combustion zone are arranged so that the preheated fuel gas entering the combustion zone is mixed with the combusted gas to provide further heating of the preheated fuel gas within the combustion zone, and wherein the combustion zone is free of catalysts and has a volume sufficient to contain the preheated fuel gas for a time sufficient for flameless non-catalytic combustion of the preheated fuel gas to occur; and an expansion stage mechanically coupled to the compression stage, the expansion stage receiving the combusted fuel gas exiting the vessel to produce an exhaust expanded gas, the energy of expansion being converted to useful rotational energy.