US 4,222,229 A · Multiple turbine electric power plant having a coordinated control system with improved flexibility

Abstract

A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. Afterburners further heat the exhaust gases from each gas turbine prior to their passage to respective heat recovery sections of the steam generator. The power plant control system provides coordinated plant control or coordinated control of selected turbines and afterburners in both startup and load operations, with load distribution optimized according to the turbines under coordinated control. Transfer between coordinated control and alternate modes of plant control may be done by operator selection or automatically upon sensed conditions.

Claims30

Dependent claims

A combined cycle electric power plant comprising at least one gas turbine and a steam turbine, a heat recovery steam generator connected to deliver steam to said steam turbine, an afterburner connected to deliver heat to said steam generator and connected to receive exhaust gas from said at least one gas turbine and adapted to impart further heat to said exhaust gas, a control system comprising at least an analog portion for operating said plant, said control system having (i) means for controlling the load operation of said steam turbine, (ii) means for controlling the load operation of said at least one gas turbine, and (iii) means for controlling the operation of said afterburner, said control system having coordinating logic means including control mode means for establishing a plurality of mode levels for carrying out respective ones of said load operations at respective different levels of automatic control, and control mode selection means for operatively selecting which of said mode level operations are carried out by said control system on which respective ones of said turbines.

A combined cycle electric power plant comprising at least one gas turbine and a steam turbine, a heat recovery steam generator connected to deliver steam to said steam turbine, an afterburner connected to deliver heat to said steam generator and connected to receive exhaust gas from said at least one gas turbine and adapted to impart further heat to said exhaust gas, a control system for operating said plant, said control system comprising respective means for controlling said steam turbine, said at least one gas turbine, and said afterburner, means for automatically coordinating the operation of selected ones of said steam turbine, gas turbine and afterburner controlling means, said steam turbine controlling means, gas turbine controlling means and afterburner controlling means each having a plurality of automatic control subsystems operating at different levels of automation and under control of said coordinating means, and means for selecting the configuration of turbine and afterburner controller means coordinated by said automatic coordinating means.

A combined cycle electric power plant, having at least one subplant comprised of two gas turbines, a steam turbine, a heat recovery steam generator connected to deliver steam to said steam turbine, and two afterburners, each connected to receive exhaust gas from a respective one of said gas turbines and deliver heated exhaust gas to said steam generator, a control system for operating said plant, said control system comprising a digital control portion and an analog control portion, said control system having control level means for providing a plurality of control modes of respective levels of automation, input means for inputting plant operation signals to said control system and output means for outputting generated control signals to said turbines and afterburners, said control level means comprising means for:

a. performing a first priority level sequence of functions;
b. performing a second priority level sequence of functions, said second sequence being adapted to perform operations depending upon performed first sequence functions, and to generate signals for controlling said steam turbine;
c. performing a third priority level sequence of functions, said third sequence being adapted to perform operations depending upon performed first sequence functions, and to generate signals for controlling said gas turbines;
d. said first sequence of functions including generating signals suitable for controlling said afterburners, and for coordinating the generating of said steam turbine, gas turbine and afterburner control signals;
and
e. selecting the configuration of which of said steam turbine, gas turbine and afterburner control signals are coordinated.

3 more elements

A combined cycle electric power plant, having at least one subplant comprised of two gas turbines, a steam turbine, a heat recovery steam generator connected to deliver steam to said steam turbine, and two afterburners, each connected to receive exhaust gas from a respective one of said gas turbines and deliver heated exhaust gas to said steam generator, a control system for operating said plant, said control system comprising a programmed digital computer control and an analog control, said controls providing a plurality of control modes of respective levels of automation, input means for inputting plant operation signals to said control system and output means for outputting generated control signals to said turbines and afterburners, said digital computer control comprising:

a. means for generating signals for controlling said steam turbine, which means performs selectable respective operations at first and second program levels;
b. means for generating signals for controlling each of said gas turbines, which means performs selectable respective operations at first and second program levels;
c. means for generating signals for controlling each of said afterburners;
d. means for coordinating the generation of said gas turbine control signals, said steam turbine control signals, and said afterburner control signals, said coordinating means further performing the function of determining which of said selectable operations are performed;
and
e. means for selecting the configuration of said gas turbine, steam turbine and afterburner control signals which are coordinated.

3 more elements

A method for operating a combined cycle electric power plant having at least one gas turbine, a steam turbine, a heat recovery steam generator connected to deliver steam to said steam turbine, and at least one afterburner connected to receive exhaust gas from said gas turbine and deliver heated exhaust gas to said steam generator, comprising generating control signals and selectively controlling therewith said gas turbine, steam turbine and afterburner, said generating comprising:

a. periodically generating steam turbine load distribution signals, as a function of plant load demand, said steam load distribution signals being generated at a first priority level;
b. periodically generating gas turbine load distribution signals, at said first priority level;
c. periodically generating afterburner control signals as a function of sensed gas exhaust temperature, at said first priority level;
d. periodically generating, at a second priority level, gas turbine control signals;
e. periodically generating, at said second priority level, steam turbine control signals;
and
f. coordinating the generating of said afterburner, steam turbine and gas turbine control signals, said coordinating step including generating said gas turbine control signals as a function of said gas turbine load distribution signals and generating said steam turbine control signals as a function of said steam turbine load distribution signals.

4 more elements

Dependencies are inferred from the claim text.

Multiple turbine electric power plant having a coordinated control system with improved flexibility

Life of this patent

Multiple turbine electric power plant having a coordinated control system with improved flexibility

Life of this patent

Abstract

Claims30