Patent ID: 11970975
Assignee: ROLLS-ROYCE PLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 9:
10. A gas turbine engine comprising a combustor, a fuel injection system, and a fuel delivery system for delivering hydrogen fuel from a cryogenic storage system to the fuel injection system, and in which the fuel delivery system comprises a pump, a metering device, and a fuel heating system for heating the hydrogen fuel to an injection temperature for the fuel injection system,
wherein the fuel heating system comprises a vaporiser configured to vaporise liquid hydrogen from the cryogenic storage system,
the metering device is a sonic fixed orifice configured to operate in a choked condition and a flow rate is controlled by adjusting (i) an upstream pressure delivered by the pump based on a measured upstream temperature of the sonic fixed orifice and an area of the sonic fixed orifice, and (ii) a pressure ratio across the sonic fixed orifice,
the vaporiser comprises a fuel offtake for diverting a portion of the hydrogen fuel from a fuel conduit for combustion in a burner located in heat exchange relationship with the fuel conduit, and
the burner is disposed concentrically around the fuel conduit.