Dynamic Simulation And Research On Control Method Of Marine Boiler-Turbine Unit

Marine stereotypical power plant usually adopts operation way of "Reactor with turbine"—thermal output of boiler will change with the load of turbine. With the problem of time-delay and large-inertia to the boiler, it's difficult to get the energy-equivalence between the quicker control link for the steamer and the slower one for the boiler. It is important for both to be coordinated better during the operation of the boiler and the turbine, especially off-design working condition. On this background, the dissertation pays attention to study dynamic characteristics of marine boiler-turbine unit.At present, simulation on boiler-turbine unit mostly focus on unit of power plant, while little attention paid on marine boiler-turbine unit. There are great differences between marine boiler-turbine unit and the unit of power plant, such as structure and working way. So the dissertation summarize available simulation algorithm on boiler and turbine, come up with the mathematical model of marine boiler-turbine unit, which including the model of heat calculation systems and propulsion systems.Based on these mathematical models and utilizing related designing data we can simulate dynamically several transient processes, such as increasing process, decreasing process etc. In this paper dynamic change of each important variable is monitored in these processes, and some dynamic simulation results of some important issues are given such as drum water level, entrance pressure of the turbine, rotate speed. Based on these, the results of simulation are analyzed; the trend and stability of dynamic change meet the demand.The ordinary PID control system and the coordinated control system with direct-energy-equivalence are designed. Under the two control systems, dynamic simulations of accelerating process and moderating process for the ship are done. The simulation results of the two different control systems for the boiler-turbine unit, under different typical load disturbances, are carried on the comparison. The result shows that the coordinated control system achieves better tracing.