桂林理工大学过程控制实习论文.docVIP

学 号： 题目类型： 报告 (设计、论文、报告) 过程控制工程实习报告 学 院： 专业(方向)： 班 级： 学 生： 2014 年 7 月 3 日 摘要 随着计算机技术的发展，可编程控制器作为通用的工业控制计算机，其功能日益强大，已经成为工业控制领域的主流控制设备。 PLC通过用户存储的应用程序来控制生产过程，具有可靠性高、稳定性好和实时处理能力强的优点。它把计算机技术与继电器控制技术有机地结合起来，为工业自动化提供几乎完美的现代化自动控制的装置。同时还能控制大量的过程参数，例如：温度、流量、压力、液位和速度。PID模块使PLC具有闭环控制的功能，即一个具有PID控制能力的PLC可用于过程控制。当过程控制中某个变量出现偏差时，PID控制算法会计算出正确的输出，把变量保持在设定值上。 正因如此，本次实习要求熟悉掌握S7—300的过程温度控制系统，该系统通过检测温度和压力来达到水箱抽水和放水的目的。压力检测下水箱压力大于设定值时，系统将压力信号转换成数字信号，再放大后输出以实现加热，温度检测值通过热敏电阻将温度信号转换成数字信号，再放大输出到水泵实现下水箱抽水至上水箱。上水箱光电传感器检测到液位高度，该信号传达到CPU，经过CPU处理后输出控制电磁阀以实现放水至下水箱，如此循环。 关键字：温控系统；控制原理；A/D转换；硬件组态；S7-300 Process control engineering practice report Student: Teacher: Abstract: With the development of computer technology, programmable controller is a general industrial control computer, its increasingly powerful, has become the mainstream of industrial control field the control equipment. User applications that store PLC to control the production process, characterized by high reliability, high stability and the advantages of real-time processing. Relay computer and control technologies are combined, almost perfect modern automatic control for industrial automation devices.Can also control the number of process parameters, such as temperature, liquid level, flow, pressure, and speed. PID closed-loop control module the PLC has the feature, a PLC can be used for process control with PID control. When a deviation of the variables is in process control, PID control algorithm will calculate the correct output, in setting the values of variables. Because of this, the practice requires familiarity with S7-300 temperature control system, by detecting the temperature and pressure in the system to achieve the purpose of pumping and drainage of the water tank. Pressure tank pressure greater than the set val