Abstract: A system for the control of an indirectly heated gas turbine comprising a primary system of controlling the temperature of heated compressed gas entering the expander, and an independent secondary system which includes a safety valve for instantaneous release of heated compressed gas to the atmosphere. The primary system controls system gas temperature and power output by modulating a flow of unheated compressed gas which bypasses the heat exchanger and mixes with the heated gas leaving the heat exchanger to produce a lower temperature gas entering the expander. The secondary system provides a backup means of overspeed prevention, and includes a safety valve to instantly discharge to the atmosphere hot compressed gas upstream of the expander by being responsive to the speed of the turbine. The safety valve includes a frangible membrane clamped between parallel flanges within the ducting, and further includes a dagger assembly for rupturing the membrane.

Abstract: A system for the control of an indirectly heated gas turbine comprising a primary system of controlling the temperature of heated compressed gas entering the expander, and an independent secondary system which includes a safety valve for instantaneous release of heated compressed gas to the atmosphere. The primary system controls system gas temperature and power output by modulating a flow of unheated compressed gas which bypasses the heat exchanger and mixes with the heated gas leaving the heat exchanger to produce a lower temperature gas entering the expander. The secondary system provides a backup means of overspeed prevention, and includes a safety valve to instantly discharge to the atmosphere hot compressed gas upstream of the expander by being responsive to the speed of the turbine. The safety valve includes a frangible membrane clamped between parallel flanges within the ducting, and further includes a dagger assembly for rupturing the membrane.

Abstract: A gas turbine set, a heat recovery boiler and a steam turbine are operated in a combined cycle to generate electric power. A gasifier generates fuel gas for the gas turbine from a reaction of fuel and compressed air supplied from the gas turbine. The booster compression process is regenerative, i.e. the air is cooled by the booster outlet air before entry to the booster and the booster outlet air is reheated by the booster inlet air prior to passage to the gasifier. Generated fuel gas is controllably heated by a heater using hot water from the heat recovery boiler. Gasifier process control is provided by a fuel ratio controller which varies the gasifier inlet fuel flow as gasifier inlet air flow varies with plant load changes.