The invention relates to sequencing the operational states of a turbine, and particularly to developing sequencing algorithms for controlling the operational states for industrial gas and steam turbines.
Industrial gas and steam turbines typically operate at predefined operational states. With respect to a gas turbine, these states relate to starting the gas turbine, accelerating the gas turbine to a rotational speed (load speed) for driving a load for power generation or a mechanical device, and shutting down the gas turbine. As an example, the operational states during startup may include starting auxiliary devices for the gas turbine, mechanically rotating the shaft of the gas turbine, and initiating ignition of combustion in the gas turbine. Other operating states are associated with accelerating the gas turbine to an idle or no-load speed, running the gas turbine at speed and under load, and shutting down the gas turbine. An industrial gas turbine operates at one of its predefined operational states. A steam turbine will also have predefined operating states and will transition between its operating states.
A software program generally referred to as a sequencer determines the current operational state of a turbine, selects the next operational state and determines when to transition from the current to the next operational state. The sequencer software module is conventionally stored and executed by a computer control system for the gas turbine.
The control system may execute other software modules which generate control commands to operate specific components of the gas turbines, typically referred to as auxiliary systems. These auxiliary systems may control the: fuel valves that regulate fuel flow to the gas turbine, starter motor that mechanically turns the compressor and turbine, instruments and sensors monitoring the gas turbine, mechanical actuators for the inlet guide vanes (IGVs), and pumps for oil and fuel. The sequencer software program communicates with the other software modules to monitor the operation of the gas turbine and notify the other modules as to the state of the turbine.
Current day sequencing software modules are written for a specific turbine model or family of models. Once written, the software instructions are tested to confirm that they properly control the turbine and are free of error. The tested software instructions are documented with comments in the software coding and manuals for using and configuring the sequencing module to a specific gas turbine. The writing, testing and documentation of the sequencing module for a new model or family of models of turbines are time consuming, expensive and require software programmers and engineers familiar with the operation of the specific gas turbine.
Historically, sequencing modules are designed and developed specifically for each model of an industrial gas turbine. Some individual manufacturers of industrial gas turbines have developed multi-model sequencers for a related group of models, such as a product family of gas turbines. These sequencing modules are limited to the gas turbine model(s) for which they are designed. Traditionally, sequencing modules have not been adapted to control gas turbines beyond those models for which the sequencing module was initially designed.
While some existing sequencing modules created for one turbine have been adapted to work on other models of turbines, this ad hoc approach to adapting sequencing modules introduces risks that the adaptation of the sequencing module does not properly sequence the new turbine through its operating states. This ad hoc approach is not an efficient approach for developing sequencers for a large number of turbine models.
Because they are custom developed for each new model or family of models of gas turbines, the sequencing modules for different models/families of gas turbines have large variations in their software structure and software instructions. To work with the sequencing modules of different models/families of gas turbine requires knowledge of the software in each module. A person qualified to work on a sequencer for one gas turbine model may not be qualified to work on the sequencer of another gas turbine module or may not be knowledgeable of subtle but important differences between sequencers for different turbines.
In view of the cost and time required to develop a gas turbine sequencer and the variations between sequencers for different models, there is a long felt and unmet need for methods and systems to reduce the cost and time required to develop sequencing modules for a wide range of models of a gas turbine.