摘 要
全氢煤气罩式炉是目前世界上用于不锈钢退火的最为先进的工业炉,而温度控制是全氢煤气罩式炉退火的关键技术之一。本文以某钢厂全氢煤气罩式炉温度控制系统为研究背景,在查阅了大量国内外相关文献的基础上,综述了国内外全氢罩式炉及其控制的研究状况、发展动态以及国产化的必要性。在熟悉生产工艺及流程控制的基础上,给出了温度控制系统整体设计方案,并着重对罩式炉退火的温度控制算法进行了较深入的研究。根据此罩式炉设备情况,退火过程的燃烧控制使用PID调节器,采用串级比值控制调节来完成,温度环为主环,燃气流量为副环控制,并在副环控制中进行相关的经验校正值系数来优化流量值的设定值。
论文还对温度控制系统软件部分进行模块化设计。在全氢煤气罩式炉温度控制方案设计的基础上应用SIEMENS的S7-300 PLC给出了温度控制算法的实现方法。
经与现场工程师一起对所提出的控制方案进行论证,此研究是可行的。除增强了系统的抗干扰能力,提高了系统工作频率等特点外,还解决了由于煤气压力的波动所引起的温度波动问题,同时保证了燃烧时的最佳空/燃比,使系统的热效比达到最佳,不仅加速了退火炉升温过程,大大缩短了工作周期;而且降低了能源消耗,使生产成本大大下降。
关键词:罩式炉;全氢;退火;温度控制系统;PLC;
Abstract
The gas bell-type annealing furnace of the whole hydrogen is used in the most advanced industry furnace that the stainless steel annealed in the world at present, whose temperature control is one of the key technologies. The paper is based on the temperature control system of the gas bell-type annealing furnace of the whole hydrogen of a steel plant, it is generally stated that the researches domestic and overseas,the development of control at home and foreign right now as well as the necessity based on consulting a great deal of documentation.On the base of konwing well manufacture technology and controlling flow,the overall temperature control system's solving scheme is presented and temperature control algorithm is emphatically studied. According to this equipment of bell-type furnace,PID controller and cascade ratio control system is used in this annealling process to control combustion,the temperature loop is main ring and the gas flow loop is pair,and experienced corrective values are suplied on it to optimize set value of flow.
The design of modularization is done on tempreture system software parts of this paper. The temperature control algorithm is implemented by using SIEMENS S7-300, based on the overall temperature control system's solving scheme.
The given control scheme is demonstrated by engineers and it is feasible, stenghten system anti-interrupt acpability , enhause system working frequency and other features all make sense, as well as deal with the temperature fluctuation as the gas pressure changes. Guaranteed the best ratio of air and gas when combusting, accelerated the process of anneal, shorten the work cycle, reduced enegy consumation, reduced costs of production dramatically.
Key words: bell-type furnace; the whole hydrogen; anneal; temperature control system; PLC