System for operating industrial gas turbine apparatus and gas turbine electric power plants preferably with a digital computer control system

• US 3,898,439 A
• Filed: 10/20/1970
• Issued: 08/05/1975
• Est. Priority Date: 10/20/1970
• Status: Expired due to Term

• Current Assignee: Gerald L. Rankin, Terry J. Reed
• Original Assignee: Gerald L. Rankin, Terry J. Reed
• Inventors: Rankin, Gerald L., Reed, Terry J.
• Primary Examiner(s): Ruggiero, Joseph F.
• Application Number:
  US05/082,467
• Time in Patent Office: 1,750 Days
• Field of Search: 235/151,150.21,151.21 60/39.13,39.24,39.28,39.34,39.36,39.42,39.44,39.75,39.81,18R,18S 444/1,936.5,936.51,936.52,936.59,933.1,933.5,962.71,949,951.16
• US Class Current: 700/287
• CPC Class Codes: F02C 9/26 Control of fuel supply F02C9/48 takes precedence; fuel valves F02C7/232
• CPC Class Codes: G06G 7/64 for non-electric machines, e.g. turbine
• CPC Class Codes: G06J 1/00 Hybrid computing arrangements digitally-programmed analogue computers G06G7/06

Abstract

A gas turbine power plant is provided with an industrial gas turbine which drives a rotating brushless exciter generator coupled to a power system through a breaker. One or more of the turbine-generator plants are operated by a hybrid digital computer control system during sequenced startup, synchronizing, load, and shutdown operations. The program system for the computer and external analog circuitry operate in a multiple gas turbine control loop arrangement. Logic macro instructions are employed in programming the computer for logic operations of the control system.

Claims

1. A gas turbine electric power plant comprising a gas turbine having compressor, combustion and turbine elements, a generator coupled to said gas turbine for drive power, a fuel system for supplying fuel to said gas turbine combustion element, means for operating said fuel system to energize said turbine, a digital computer and an input/output system therefor, means for operating said computer to determine a fuel demand representation for desired turbine operation, means for controlling said fuel system operating means as a function of said fuel demand representation, means for detecting a plurality of independent turbine exhaust temperature values, means for operating said computer to determine a temperature representation of actual exhaust temperature from said detected values, means for operating said computer to determine an exhaust temperature reference value, means for operating said computer to average said detected values in a predetermined manner, means for operating said computer to compare said individual values to said average result and to reject values which are too low by a predetermined temperature amount, means for operating said computer to recompute said average result if a reject occurs, and means for operating said computer to determine an exhaust temperature limit representation as a function of the final accepted average actual temperature and said temperature reference, said fuel demand representation including said temperature limit representation.

2. A gas turbine electric power plant comprising a gas turbine having compressor, combustion and turbine elements, a generator coupled to said gas turbine for drive power, a fuel system for supplying fuel to said gas turbine combustion element, means for operating said fuel system to energize said turbine, a digital computer and an input/output system therefor, means for operating said computer to generate a plurality of fuel demand representations as respective functions of predetermined turbine limit conditions, means for operating said computer to generate a speed reference representation, means for generating a fuel demand signal to control said fuel system operating means as a function of said speed and fuel demand reference representations, means for operating said computer to determine said actual fuel demand signal, and means for operating said computer to cause each fuel demand representation in its nonlimiting state to correspond in value to said actual fuel demand signal to provide for fast limit reentry control.

3. The electric power plant as set forth in claim 2 wherein each fuel demand representation is made equal to the integral of the difference between said fuel demand representation and a fuel demand signal representation plus a predetermined bias value representation.

4. The electric power plant as set forth in claim 1 which further includes means for operating said computer to apply a rate action to said final actual exhaust temperature average value and to sum the result of the rate action with said average temperature value.

5. The electric power plant as set forth in claim 4 which further includes means for operating said computer to apply said rate action only during rising exhaust temperature.

6. A gas turbine electric power plant comprising a gas turbine having compressor, combustion and turbine elements, a generator coupled to said gas turbine for drive power, a fuel system for supplying fuel to said gas turbine combustion element, means for operating said fuel system to energize said turbine, means for detecting generator load, a digital computer and an input/output system therefor, means for operating said computer and for generating a fuel demand signal for controlling said fuel system operating means to energize and operate said turbine during startup and load operations, means for operating said computer to limit the rate at which fuel demand changes can be made for load operating level changes, and means for operating said computer to determine a representation of said fuel demand signal and to generate a load rate limit output representation equal to said fuel demand signal representation plus a small step increment representing a stored limit load rate value only if said fuel demand signal is less than said present load rate limit output representations.

7. The electric power plant as set forth in claim 6 which further includes means for operating said computer to cause said load limit rate output representation to track said fuel demand signal representation plus a predetermined bias during nonlimiting operation of said load rate limit output representation.

8. A gas turbine electric power plant comprising a gas turbine having compressor, combustion and turbine elements, a generator coupled to said gas turbine for drive power, a fuel system for supplying fuel to said gas turbine combustion element, means for operating said fuel system to energize said turbine, a digital computer and an input/output system therefor, means for operating said computer to determine a fuel demand representation for desired turbine operation, means for controlling said fuel system operating means in accordance with said fuel demand representation, means for detecting actual generator load, means for operating said computer to generate a load reference representation and a load error representation from the difference between said reference and actual load values, and means for operating said computer to make said fuel demand representation normally correspond to said load error representation during constant load control turbine operation.