Research On Control System Of Gas Turbine-steam Turbine Combined Cycle Of Natural Gas Compressor Station

In this paper,based on the actual demand of engineering,the gas-steam combined cycle control system for heat recovery and utilization of gas turbine in natural gas compressor station is studied.Firstly,this paper puts forward the technical scheme of reforming the gas turbine of the compressor station by using the principle of gas-steam combined cycle.The technical scheme transforms the compressor station into an independent gas-steam combined cycle power station.Based on the original equipment,the waste heat boiler,steam turbine,generator,motor and auxiliary equipment are added,and the technical parameters of the main equipment are determined according to the principle of equipment type selection.The compressor is driven by electric power to pressurize the natural gas pipeline.The scheme gives full play to the flexible,efficient and convenient characteristics of "electric power drive",which not only improves the efficiency of a single gas turbine,but also reduces the use of a gas turbine and improves the overall fuel efficiency of the compressor station.Secondly,based on the thought of modular modeling,this paper studies and analyzes the structure,principle and operation characteristics of the main components of the combined cycle.Then,this paper establishes the thermodynamic model of gas turbine,waste heat boiler and steam turbine,and builds the overall thermodynamic model of the combined cycle through the interaction of important parameters among the modules.The model is verified by comparing with the actual operation data of the same type gas turbine.Then,aiming at the characteristics of large change,frequent change and predictable and uncontrollable change of compressor station load,a fuzzy PID controller is designed and optimized in this paper.Based on the monitoring of load operation state and the prediction of load change,the control strategy of cooperative load distribution of gas turbine and turbine was proposed to improve the capacity of the combined cycle control system to cope with large load shocks.Finally,the relationship between the fuel value of the combined cycle and the total power is obtained through static simulation and dynamic simulation experiments of the combined cycle control system at various operating conditions.The simulation results show that the fuzzy PID controller and the coordinated load distribution control strategy greatly improve the technical indexes of the combined cycle control system to cope with the load changes,so that it can meet the specific control requirements of frequent and variable load of the compressor station.The research achievement of this paper has theoretical significance and application prospect for the engineering application of gas-steam combined cycle control system.