| Supercharge boiler is the kernel equipment of steam dynamical device in ship. In order to ensure its security, the auto-control of it is very inportant. The boiler water level is a mostly index of boiler function. Because of the influence of all aspect ,it can not be exactly measure at all times. This phenomenon is more bad in marine boiler whose dynamic characteristic changed greatly .For solving the emergent problem, This paper does some work as follows:1) The thesis bases on the marine boiler principle of work by analysing the dynamic property of boiler drum water level, gets the variety rule of boiler drum water level, and through certain suppose and predigest, gets the approximate model. Then the thesis lucubrate the arithmetic of boiler drum water level, based on the characteristic of the boiler of ship which is inlinearity, instability parameter, and diffcultly to build accurate math model, the best mothod for controlling the water-level is analysed, and the simulation with the Simulink on control system is carried out under the action of noise.2) We designed the boiler monitoring device which realized high precision collection and treatment of the water-level .The system takes effective method of water level display , malfunction alarm and forecast, and uses control model of three- variable and PID control in the drum water level. It can efficiently overcome the influence of fake water level. Thinking of safety, we realized redundancy controlling.3) For making procedure assembling, debugging and change of control system project more convenient, and also for expanding the other process control of the object, We adopt modularized construction form in the procedure design and each function module appear in the sub-procedure form. By communicating with engine room centralized console, we realized online modificating working parameter and autosaving boiler work data. It is convenience for people to supervise by designing a friendly interface between people and machine in computer .The design makes use of the tiny computer to compose of boiler movement parameters and the automatic examination of control the system, and makes use of the computer software to replace numerous industrial emulate-type automatic meter and to constitute the control system with special function, and makes use of the advanced tiny computer technique to reform the traditional unenlightened industry . The system can well fit the practicability characteristic of the ship boiler . This scheme made a good result and realized the anticipative control requirement that are in accordance with the require of engine room monitoring in modern times ship. |
