Steady State Performance Calculation And Dynamic Process Simulation In Marine Supercharged Boiler

Supercharged boiler is the main equipment of the marine power plant. Compared with non-supercharged boiler, it has many advantages such as light-weight, small-volume, excellent mobility etc, and its thermal performance parameters and dynamical characters are different from the conventional boilers.Depending on the certain structure of some type supercharged boiler, this paper determined the thermal calculating methods for the supercharged boiler according the characteristic of the flue-gas system and the steam-water system. The main performance parameters for three different typical loads of the supercharged boiler were educed by the methods and were deemed to the validated data for the simulated model of the supercharged boiler. On the basis of the heat transfer theories and the conservations of mass, momentum and energy, the supercharged boiler was divided into several different models according the different function, and the models included the furnace, the super-heater and the economizer. Using the lumped parameter methods, the dynamic mathematical simulated models was developed under the Matlab/Simulink software, and the mathematical simulation were carried out.By the thermal calculating and the mathematical simulation, some outstanding conclusions were gained as follows. Firstly, radiation heat transfer and convective heat transfer in supercharged boiler were influenced by the fuel's quantity, and their proportion in the total heat transfer quantity would be changed obviously when the load was changed. Secondly, the steady state datas had a sharp different as the load was different, such as the pressure of the steam-gas. Thirdly, the method which was used to divide the different model according the different function was viable, and the results achieved by computer simulation were agreed with the steady state's data very well. Fourthly, the response of the steam-water system was slower than the flue-gas system during the dynamic adjusting process. The last, the fluctuation range of the different metal's temperature was different, and the fluctuation range of the water walls was less than the range of the super-heater and the economizer.