Method and system for a gas turbine engine air ventilation purge circuit

A method of supplying a combustion chamber with at least one combustible fluid using a fuel supply system, said fuel supply system coupled in flow communication with a first purge system, said first purge system including at least two isolation valves that define a cavity therebetween, said method comprising:

• channeling the at least one combustible fluid to the combustion chamber through a fuel supply isolation valve;
• capturing combustible fluid leaking by any of the at least two isolation valves into the cavity;
• and
• entraining the leaking combustible fluid in a flow of ventilation air directed to the cavity and exiting the cavity through a vent to atmosphere.

A gas turbine engine system comprising:

• a compressor comprising a low pressure inlet, a high pressure outlet, and a bleed port configured to extract air at a pressure between said low pressure inlet and said high pressure outlet;
• a combustion chamber comprising a fuel injector;
• a turbine coupled in serial flow communication with said compressor and said combustion chamber;
• at least one supply circuit configured to supply said combustion chamber with a combustible fluid;
• and
• at least one purge circuit coupled in flow communication with said at least one supply circuit, said purge circuit comprising:
• at least two isolation valves defining a cavity between said at least two isolation valves;
• a source of relatively high temperature purge air coupled in flow communication to said cavity through one of said at least two isolation valves;
• a source of relatively low temperature ventilation air coupled in flow communication to said cavity;
• and
• a vent coupled in flow communication to said cavity,
• said at least one purge circuit configured to channel a flow of relatively low temperature ventilation air from said source relatively low temperature ventilation air through said cavity to said vent during operation of said combustion chamber.