Abstract: The clearance control system includes a closed air circuit having a heat exchanger, a circulation compressor and an air heater in series for flowing air heated or cooled to higher and lower system-set discharge temperatures in the casing of rotating machinery to expand or contract the casing, respectively, to maintain optimum clearances between the rotating blade tips and the casing. At start-up, the air heater is energized to supply heated air to and expand the casing. During start-up and subsequent to this initial phase, the air heater is deenergized and the air cooling system is actuated by closing a heat exchanger bypass valve and opening a shutoff valve, enabling the air to be cooled in the heat exchanger. By controlling the flow of coolant to the heat exchanger, the lower set discharge temperature of the air exiting the circulation compressor can be regulated during steady-state operation to maintain the casing contracted for optimal clearance.

Abstract: A positive displacement pump supplies a low lubricity liquid fuel through a main supply line to the combustors of a turbine. A pressure transducer and a flow meter are provided in the main fuel supply line. The fuel is supplied to a pressure compensated fuel delivery valve which divides the fuel equally among the combustors and affords pressure compensation. A controller is responsive to the pressure in the main fuel supply line to control a bypass pressure valve to supply fuel in the main supply line at a predetermined pressure. The controller also controls the total volume of fuel flow rate through the pressure compensated fuel delivery valve responsive to the flow meter. In another form, a centrifugal pump supplies fuel to the pressure compensated fuel delivery valve. A controller responsive to the flow meter in the main supply line controls the total fuel flow rate to the valve which divides the fuel equally among the combustors at equal flow rates.