Dynamic Simulation Of Marine Supercharged Boiler

Supercharged boiler is a stream power system, which provides fuel gas with a certain pressure and temperature to the furnace that is compressed by turbo-compressor instead of steam-powered fan. The boiler's advantages are light-weight, small-volume and is appropriate for ships and warships.In this paper, the research object is the working process of a marine supercharged boiler,-based on the energy conservation equation, momentum equation, mass conservation equation, heat transfer heat transfer relationship,-lumped parameter method used to establish the furnace, riser, drum, superheater and economizer mathematical model and simulation model, and on this basis, the dynamic simulation is implementation.This paper analyses the working process of refrigerant (fuel gas,vapour and water) and thermodynamic properties,various components of the boiler temperature and heat exchange changes.Simulation results show that:in the situation of small amplitude perturbations of fuel, fuel gas has more rapid and stronger response to disturbance; various parts of the boiler flue gas parameter changes and disturbances are at the synchronization; the response to disturbance of water and vapor side is relatively slow, the parameters of the water in the drum have small changes, the changes in the steam parameters is considerable, water level changes and disturbance in the opposite direction.. The boiling heat transfer process exsits in the upper convective tubes, and the medium is mixture state,little changes exsit in mixture temperature and wall temperature.The convergence time of the superheated steam temperature is longer and amplitude is also much; changes of the water inside the economizer is slow, its heat transfer process is at the peak response, when the load disturbance increases 10%,vapor pressure increases significantly.Based on the different marine supercharged boiler fuel in the small amplitude perturbations of the internal parameters of working medium, the paper studies material and energy boiler system transfer, flow processes of different conditions and the dynamic relationship between input and output,reveals the complicated thermal mechanism of supercharged boiler, provides the basis for optimizing the boiler design, automatic control systems and fault diagnosis of the marine supercharged boiler system.