Process for regulating gas pressures of catalyst regenerator expansion turbines

A process for regulating the gas pressures of a system including a regenerator operating interconnected with a reactor, the process comprising the steps of:

• providing a flue gas line and a flue gas branch line;
• providing at least one gas expansion turbine connected to the flue gas branch line, said turbine being connected to a load;
• providing an inlet control valve in the flue gas branch line;
• providing a flue gas bypass line with a bypass valve;
• providing a process regulator for detecting pressure and for opening and/or throttling the inlet control valve and/or bypass valve;
• recording correcting variables of the inlet control valve and recording correcting variables of the bypass valve, said correcting variables being a relationship between a control signal sent to a respective said valve and an actual gas flow through said respective valve, once during a first regulation procedure with operation of the gas expansion turbine and once during a second regulation procedure without operation of the gas expansion turbine;
• providing a plurality of function generators which preset the correcting variables for the inlet control valve as well as the bypass valve with a regulator signal, in which a first set of said plurality of function generators is stored during said first regulation procedure and in which a second set of said plurality of function generators is stored for said second regulation procedure, said plurality of function generators being connected for conditioning an output of said process regulator;
• providing a valve position transmitter for said inlet control valve and for said bypass valve;
• forming set points for said position transmitters for output variables of said plurality of function generators for the valve position transmitters;
• and
• changing over from said first regulation procedure to said second regulation procedure via changeover switches during a switching off of the gas expansion turbine.

A process for regulating the gas pressures of a system with a regenerator interconnected with a reactor, the process comprising the steps of:

• providing a flue gas line
• providing a flue gas branch line connected to said flue gas line;
• providing at least one gas expansion turbine connected to the flue gas branch line, said turbine being connected to a load;
• providing an inlet valve in the flue gas branch line;
• providing a flue gas bypass line connected to said flue gas line;
• providing a bypass valve in said bypass line;
• measuring a pressure in said flue gas line;
• controlling said inlet control valve and said bypass valve to maintain a desired pressure in said flue gas line, said controlling including:
• generating a regulator output signal dependent on said measured pressure and said desired pressure;
• converting said regulator output signal into a first inlet valve signal and a first bypass valve signal for maintaining said measured pressure substantially equal to said desired pressure with said turbine operating;
• converting said regulator output signal into a second bypass valve signal for maintaining said measured pressure substantially equal to said desired pressure with said turbine not operating;
• sending said first inlet valve signal to said inlet valve and sending said first bypass valve signal to said bypass valve when said turbine is operating;
• sending said second bypass valve signal to said bypass valve when said turbine is not operating.