Simulation analysis on performance of fast variable load for marine steam power system

[Objectives] The fast variable load capacity of steam power system is a key technical index to determine the maneuverability of ships, which is of great significance to the safety and stability of marine navigation.[Methods] Simulation model of steam power system including of supercharged boiler,steam turbine unit,feedwater pumps and other equipments is established. Based on the experimental data,the stability and accuracy of the simulation model is verified. The dynamic performance of steam power system is simulated under fast rising and reducing load conditions.[Results] The calculation results show that a slow matching rate between turbocharger unit and boiler,which restricts the fast rising load capacity of the steam power system. Meanwhile,steam back brake of steam turbine unit is lack of ability,which restricts the fast reducing load capacity of the steam power system.[Conclusions] The research results can provide theoretical support for the design and optimization of the steam power system of a real ship

Response characteristics of ship steam power system under switchover of turbine feed water pump

[Objectives] The switching performance of turbine feed water pump is a key technical indicator to decide the operation stability of ship steam power system, and it is of great significance to the safety of navigation.[Methods] Using the Modular Modeling System(MMS) thermal engineering system simulation software, a simulation model of ship steam turbine power system based on the switching principle of turbine feed water pump is established. Meanwhile, the accuracy of the simulation model is verified by experiment data. The dynamic response of turbine feed water pump to steam-water cycle of steam turbine power system is analyzed under high-speed and low-speed conditions.[Results] The calculation results show that switchover of turbine feed water pump can meet the water supply demand of supercharged boiler under high-speed and low-speed conditions. After switching, the system can run stably under low-speed condition, but the operation of the system is unstable after switching under high-speed condition. It shows that the water level of the condenser rapidly rises to an extremely high level, and the water level of the deaerator drops sharply to an extremely low level. Severe pressure fluctuation occurs in exhaust steam and micro superheated steam.[Conclusions] The research results can provide theoretical support for the optimization of the switching scheme of the steam turbine feed water pump