Simulation Study On Unsteady Process Of Marine Intermittent Steam Supply System

As the steam source of marine intermittent steam supplying system,the normal and stable operation of supercharged boiler can guarantee the security of the whole system.When the steam is supplied to the outside,the steam flow rate is large and fast,and the steam supply is intermittent.If the steam is supplied directly by the supercharged boiler,the supercharged boiler can not bear,so it has a serious safety hazard.How to ensure the steam supply time and the requirement of the steam supply,and how to keep fast,stable and reliable operation of the whole system and maintain the supercharged boiler itself,are problems that must be solved.They are also the focus and difficulty of marine steam process.It is meaningful to research them.The intermittent steam supply system of the ship is used to realize the process by increasing the steam accumulator in the middle and the corresponding heat accumulator.In this paper,marine intermittent steam supply system is the research object.The mathematical model of thermal system is established based on the lumped parameter method,and the dynamic simulation model for the steam system is established by the GSE simulation platform.The experimental data is use to check and revise the simulation model.Using the simulation model to study the influence factors for the stability and fast of the marine intermittent steam system.The influence factors include quick opening rate,quick closing rate,quick opening degree,the valve type,automatic control parameters,steam source parameters and other factors.Through this research,the minimum fluctuation and the shortest time criterion are obtained,and then the simulation analysis of the unsteady process of the marine intermittent steam supplying system is carried out.The results of simulation show that through adding steam accumulator in the intermittent steam supply system of the ship,and adopting the follow-up charging mode,the process of large flow,fast and intermittent steam supplying can be realized.In this paper,by means of a large number of orthogonal experiments,the preliminary criteria for the minimum fluctuation and the shortest time of the system with different valve types and different closing rates are given.It provides reference for practical application.The combination of different types of valves can achieve maximum fluctuations of not more than 0.01 MPa,and at this time the filling time is not more than 29 s.When using different combination of different types of valves,the steam time is not greater than 24.1s,and the fluctuation is not greater than 0.3MPa.Under the same conditions,when the charging valve is a linear valve,the charging time is shorter and the fluctuation is smaller.When the bypass valve is a percentage valve,the fluctuation is the smallest and the charging time is the longest.When the bypass valve is a linear valve,the fluctuation is the largest and the charging time is the shortest.The research content of this paper can play a good role in supporting the control strategy of the steam supplying system and improving the economic performance.