Control of the fuel quantity for gas turbine driving systems

Claim 1

A CONTROL INSTALLATION FOR SELECTIVELY CONTROLLING THE FUEL QUANTITY FOR GAS TURBINE DRIVE UNITS COMPRISING: FUEL SUPPLY MEANS PROVIDED WITH FUEL ADJUSTING MEANS EFFECTIVELY ENABLING ADJUSTMENT OF THE METERED FUEL QUANTITY TO BE INJECTED INTO THE DRIVE UNIT AND WITH A WORKING CIRCUIT INCLUDING A FIRST ELECTRICAL PATH AND A SHUNT PATH HAVING SWITCHING MEANS FOR EFFECTIVELY CONTROLLING SAID FUEL ADJUSTING MEANS, TEMPERATURE RESPONSIVE CONTROL MEANS OPERABLE IN DEPENDENCE ON THE TEMPERATURE OF THE PRODUCED DRIVING GASES INCLUDING TEMPERATURE SENSING MEANS EXPOSED TO SAID DRIVING GASES, PRESELECTOR MEANS FOR PRE-SELECTING A DESIRED TEMPERATURE HAVING POTENTIOMETER MEANS ESTABLISHING A PRE-SELECTED VOLTAGE CORRESPONDING TO SAID DESIRED TEMPERATURE, AMPLIFIER MEANS, AND FIRST CIRCUIT MEANS INTERCONNECTING SAID TEMPERATURE SENSING MEANS AND SAID PRESELECTOR MEANS WITH THE INPUT OF SAID AMPLIFIER MEANS IN SUCH A MANNER THAT THE TEMPERATURE DEVIATION OF THE PREVAILING TEMPERATURE IN THE GAS TURBINE DRIVE UNIT FROM THE PRESELECTED DESIRED TEMPERATURE IS REPRESENTED AT THE OUTPUT OF SAID AMPLIFIER MEANS AS A DIRECT-CURRENT VOLTAGE, THE POLARITY OF WHICH CORRESPONDS TO THE DIRECTION OF CONTROL DEVIATION. SECOND CIRCUIT MEANS OPERATIVELY CONNECTING THE OUTPUT OF SAID AMPLIFIER MEANS WITH SAID SWITCHING MEANS OF SAID WORKING CIRCUIT TO SELECTIVELY OPEN SAID SHUNT PATH AND THEREWITH CONTROL SAID FUEL ADJUSTING MEANS BY SAID FIRST-MENTIONED DIRECT-CURRENT VOLTAGE TO SEEK TO SUBSTANTIALLY CONTINUOUSLY ADAPT THE PREVAILING TEMPERATURE TO SAID PRESELECTED DESIRED TEMPERATURE, AND SPEED-LIMITING CONTROL MEANS RESPONSIVE TO THE SPEED OF THE DRIVE UNIT AND INCLUDING GENERATOR MEANS PRODUCING A VOLTAGE PROPORTIONAL TO THE SPEED OF THE DRIVE UNIT AND OPERABLE TO EFFECTIVELY REPRESENT THE CONTROL DEVIATION OF THE PREVAILING SPEED OF THE DRIVE UNIT FROM A MAXIMUM PERMISSIVE SPEED THEREOF AS A DIRECTCURRENT VOLTAGE, SAID SPEED LIMITING CONTROL MEANS BEING OPERABLE TO OVERRIDE SAID TEMPERATURE-RESPONSIVE CONTROL MEANS ONLY IN RESPONSE TO THE DRIVE UNIT EXCEEDING THE PERMISSIVE SPEED THEREOF TO THEREBY TEMPORARILY REDUCE THE INJECTED FUEL QUANTITY, AND THIRD CIRCUIT MEANS OPERATIVELY CONNECTING SAID GENERATOR MEANS WITH SAID SWITCHING MEANS OF SAID WORKING CIRCUIT TO OPEN SAID SHUNT PATH ONLY WHEN SAID PERMISSIVE SPEED HAS BEEN EXCEEDED.