A device heating a fluid and usable in a rocket launcher to pressurize a liquefied propellant. The device includes a first burner performing first combustion between a limiting propellant and an excess propellant; a first heat exchanger in which first burnt gas from the first combustion transfers heat to the fluid; at least one second burner into which both the first burnt gas and some limiting propellant are injected to perform second combustion between the limiting propellant and at least a portion of unburnt excess propellant present in the first burnt gas. The second burnt gas from the second combustion flows through a second heat exchanger to transfer heat to the fluid. Burnt gas from each combustion flows in respective burnt gas tubes within a common overall heat exchanger including the heat exchange units, the gas transferring heat to the fluid, the fluid flowing between the burnt gas tubes.

The invention concerns a gas turbine combustion system, including a gas turbine. The gas turbine includes at least one compressor, at least one combustion chamber for generating working gas, wherein the combustion chamber connected to receive compressed air from the compressor, at least one turbine connected to receive working gas from the combustion chamber. The combustion chamber consists of an individual can-combustor or comprising a number of can-combustors arranged in an annular can-architecture, wherein the can-combustor having at least one premixed burner. The ignition of the mixture starts at the premixed burner outlet and the flame is stabilized in the region of the premixed burner outlet by means of a backflow zone. The can-combustor comprising a number of premixed burners arranged uniformly or divided at least in two groups within the can-combustor.