Study And Application On Real-time Dynamic Simulation Model For Heavy-Duty Gas Turbine Combined Cycle Power Unit

Currently, China is not capable of independently developing the large capacity Gas-Steam Combined Cycle power unit (GSCC). The computer simulation plays an important role in every stage of development and application of GSCC, such as design, production, commissioning & testing and operation etc. The performance analysis algorithm and overall real-time dynamic simulation model of the heavy-duty gas turbine combined cycle power unit are studied and developed in the thesis, and the research results are used to analyse the unit characteristics and develop the real-time simulation training system of GSCC. The following research work has been done.The working mechanism of the main equipment in GSCC is researched. The GSCC thermodynamic theory model is built, the problems and characteristics, which should be considered and reflected during developing the dynamic simulation model, are discussed. Based on the theory model, the method to research the GSCC performance is put forward by combining the linear small deviation approach and operation data, and the GSCC performance analysis algorithm is developed. Using the real power unit as an example, the impact coefficients on the GSCC performance are calculated in detail when the primary parameters vary. The variational relation between the GSCC performance and thermodynamic parameters are quantitatively analyzed. The theory basis is provided for increasing the output and thermal efficiency of GSCC, and the valuable calculation data are provided for the research of the GSCC off-design performance.Based on the stage-stacking principle, the method of calculating compressor performance curve is proposed by combining the improved stage-stacking method and operation measured data of the real GSCC, and the method of calculating discharge pressure of every turbine stage is presented by using the principle of the pressure node in fluid network. The modeling problem, which is difficult to build comparatively accurate dynamic simulation model because the basic data of the axial flow compressor and turbine are not available, is effectively solved. Aided by these calculation methods, the heavy-duty gas turbine real-time dynamic simulation model is studied and set up. In the simulation model, when the Inlet Guide Vane (IGV) blade incidence or the flux of air bleeding and extraction in different stages of the compressor change, the impact of the variation on the compressor performance are considered. The influence of gas turbine blade cooling air on every stage thermal performance is calculated stage by stage. The volume-inertia and the heat-inertia of the combustor and transition section are reflected in simulation processes. Based on the mass and energy conservation laws, by using the thermodynamic engineering design calculation method, empirical formulas, correlative theory equations and the basic module in fluid network model, the dynamic simulation models for the thermal equipment in GSCC such as unfired HRSG, steam-turbine, condenser, pump etc. are researched. Combining the steam-water and gas fluid network models, the real-time simulation model for the bottom cycle system in GSCC is built.With the STAR-90 simulation supporting system, by combining the dynamic simulation models of the heavy-duty gas turbine and the bottom cycle system developed in the paper, the overall real-time dynamic simulation model for the thermal systems of the M701F GSCC is built, which the simulated object is the No.1 power unit installed in Shenzhen Guangqian Power Plant. The precision and rationality of the model dynamic behavior are validated by using the real unit operation data and combustion commissioning and testing data. Based on the simulation model, the following research work has been done: forecasted the operating characteristics of the real unit, analyzed the control system regulation rule, investigated the thermal performance of the stages in compressor and turbine, built the overall performace characteristics curves, and provided the theoretical guide for the daily operation of the GSCC. By following the equipment algorithms developed in the thesis, combining the correlative application software, the real-time simulation training system for V94.3A GSCC unit has been first successfully developed in China. The acceptance tests for the simulation training system were passed, and the system has been delivered to the customer.