Starting method and system for a gas turbine

A starter system for a gas turbine machine, comprising:

• a reservoir for pressurized gas;
• an expanding rotary vane motor communicating with said reservoir and operably coupled to drive said machine in a first mode;
• charging means communicating with said reservoir for delivering pressurized gas thereto from said machine to recharge said reservoir;
• control means for selectively controlling flow of pressurized gas from said reservoir to said motor to actuate the latter and initiate starting of said machine during the first mode of operation of said system, said control means for interrupting said flow of gas from said reservoir to said motor and allowing said delivery of pressurized gas to said reservoir from said charging means so as to recharge said reservoir to recharge said reservoir during a second mode of operation of said system;
• and
• a pressure regulating valve communicating with said reservoir and said motor, operable to reduce pressure of said flow of gas supplied from said reservoir to a preselected, relatively constant lower level prior to delivery to said motor.

A method of starting a rotary gas turbine machine, comprising the steps of:

• delivering a starting flow of pressurized gas from a reservoir to an expanding rotary vane motor to actuate the latter, said motor operably coupled to rotate said machine;
• rotating said machine with said motor;
• generating a working gas flow through said machine by the rotation thereof;
• interrupting said starting flow of pressurized gas to said motor after said machine reaches a self-sustaining speed;
• diverting from the machine at least a portion of the working gas flow generated in the machine during said self-sustaining operation thereof;
• recharging the reservoir by delivering said diverted working gas flow to said reservoir;
• amplifying the pressure of said diverted working flow to a pressure sufficient to effect actuation of said motor during a subsequent starting of said machine;
• and
• regulating the pressure of said flow of pressurized gas being delivered to said motor during said starting step to a relatively constant preselected value substantially less than said pressure of gas in the reservoir.

A prime mover engine having self-starting capabilities, comprising:

• a gas turbine machine having a rotary compressor;
• an expanding rotary vane starter motor operably directly connectable with said machine for effecting rotation of said compressor to initiate starting of said machine;
• a reservoir for pressurized gas;
• control means for selectively communicating said reservoir with said motor to actuate the latter and effect rotation of said compressor, said control means including a pressure regulating valve means for substantially reducing pressure of gas supplied from said reservoir;
• to a relatively constant preselected value and
• pressure amplifier means operably connected with said reservoir and said compressor to be supplied with gas at a first pressure from said compressor during operation of said machine, said amplifier means operable to deliver gas to said reservoir at a second pressure greater than said first pressure for charging said reservoir during operation of said machine, thereby recharging said machine for repetitive starting without use of a source of energy external to said machine for actuating said motor.

In combination:

• a gas turbine machine having a rotatable shaft and a gas compressor mounted to said shaft, said machine adapted to generate a flow of gas during operation thereof;
• a reservoir for storing pressurized gas at a preselected pressure;
• a first conduit communicating with said reservoir;
• an expanding rotary vane type pneumatic motor means communicating with said first conduit, having a rotary power output shaft directly connectable to said shaft of the machine to drive said compressor connecting said reservoir and means for receiving pressurized gas from said first conduit to generate power and for initiating rotation of said compressor both by pressure of said gas delivered to said motor as well as by expansion of said gas while in said motor;
• a first control valve disposed in said first conduit selectively shiftable between a first position prohibiting flow of pressurized gas through said first conduit, and a second position allowing flow of pressurized gas to said motor to actuate the latter and start said machine;
• a pressure regulating valve means in said first conduit downstream of said first control valve for regulating pressure of said pressurized gas in said first conduit to a relatively constant level lower than said preselected pressure prior to delivery to said motor;
• a second conduit extending between said machine and said reservoir, conducting recharging gas to said reservoir from said flow of gas in said machine;
• a second control valve disposed in said second conduit selectively shiftable between first and second positions respectively prohibiting and allowing recharging flow of pressurized gas through said said conduit;
• means in said conduit for preventing reverse gas flow therethrough from said reservoir to said machine;
• and
• pressure amplifier means in said second conduit downstream of said second control valve and upstream of said means for preventing reverse flow, for raising the pressure of said recharging flow of gas to said preselected pressure level, said pressure amplifier means being driven by said recharging flow of gas in said second conduit.