Patent ID: 7066396

Claim:
A heating system comprising: a fluid heater vessel having a fuel inlet, an oxidant inlet and flue gas exhaust means for exhausting flue gases from said fluid heater vessel, said flue gas exhaust means comprising a first economizer section downstream of said fluid heater vessel and a condenser section disposed downstream of said first economizer section, said condenser section having a condensate outlet; an oxidant preheater having an ambient oxidant inlet and a heated oxidant outlet, said heated oxidant outlet in fluid communication with said oxidant inlet; a first fluid heat exchange means disposed in thermal communication with said fluid heater vessel, a second fluid heat exchange means disposed in thermal communication with said first economizer section, a third fluid heat exchange means disposed in thermal communication with said oxidant preheater, and condenser means for condensing flue gas water vapor, said condenser means disposed within said condenser section; one of a feed water tank and a de-aerator vessel; and fluid communication means for providing fluid communication from said condenser means into said third fluid heat exchange means, from said condensate outlet into said third fluid heat exchange means, from said third fluid heat exchange means into said condenser means, from said condenser outlet and said condenser means into said one of said feed water tank and said de-aerator vessel, from said one of said feed water tank and said de-aerator vessel into said second fluid heat exchange means, from said second fluid heat exchange means into said first fluid heat exchange means, and from said first fluid heat exchange means into said one of said feed water tank and said de-aerator vessel.