毕业设计论文-汽包水位液位的三冲量控制.doc

摘 要 锅炉是多数工业过程中常用的热能动力设备,工业锅炉控制系统是复杂的控制系统。由于设备分散、管理不善或技术原因,使多数锅炉难以处于良好的工况,增加了锅炉的燃料消耗,降低了效率。为确保安全,稳定生产,对锅炉的自动控制十分重要,其中汽包水位是一个非常重要的被控变量。汽包水位是锅炉安全运行的重要参数，同时也是衡量锅炉汽水系统物质是否平衡的标志。锅炉给水控制的任务是维持汽包水位在一定范围内变化。水位偏低，会造成锅筒各部位的温度偏差，形成热应力，极限情况下会出现裂纹，甚至有爆炸等危险，水位偏低也会造成水系统自然循环不畅，严重时个别上下水管会产生自由水面，流动停滞，从而导致管爆事故。锅炉汽包水位偏高时，会影响汽水分离的速度和蒸汽的质量，同时也是安全生产不允许的。而在负荷变化时，又极易影响到水位的快速变化，因此，必须设计功能完善的三冲量水位调节器来维持水位不变或在规定的范围内变化。 SHCAN6102智能测控组件是一种具有CAN现场总线通讯功能的现场智能控制器。它不仅可用于现场总线控制系统（FCS），而且可以单独构成一个现场控制单元，三冲量水位调节器就是依托SHCAN6102智能测控组件实现的。 : 汽包水位 三冲量控制 SHCAN6102 ABSTRACT Boiler is thermal power plant usually used in most industrial processes and industrial boilers control system is a complex control system. Because of scattered equipment, poor management or technical reason, it is difficult to work in good condition for the majority of boilers and increased their fuel consumption and reduced the work efficiency. It is very important to control boiler automatically in safety and stabilization, and boilers drum water-level is an important variable to be controlled. Drum boiler water level is an important parameter of normal operation and an mark to measure the material balance.The task of boiler feed water control is to keep the drum water level in a certain range. The low water level, causing the temperature deviation of each part of Drum, can produce a thermal stress. The limit of this situation will make the boiler crack and even explosive. Meanwhile, the low water level will cause the natural cycle of poor water system, and individual serious water pipes from top to bottom may have free water, the flow of stagnation, leading to the explosion accident. It will affect the separation speed of steam from the steam quality when boiler water level is high, which is not allowed in normal operation. It is vulnerable to impose the rapid changes on water level during changes in the load. Therefore, three-volume water regulator must be designed to maintain the water level or keep it within the range of provis