高温盐浴炉温度控制系统

论文编号:ZD1234   论文字数:16927,页数:45  附原理图，外文翻译

摘  要
                              
 盐浴炉是热处理车间的主要加热设备之一，多用于零件的淬火、回火、正火等处理。目前使用的盐浴炉大多采用的是分档调节、人工控温的落后办法。这种控制方法能耗高、控温精度差，而且炉温波动大，噪声大。电压调节通过人工转换无载分接开关机械触电实现，造成无载分接开关容易烧坏，维修频繁，并且温度波动大，有时不能满足某些工件的加工要求。
 为使之一设备能更加有效地工作，本文提出了对盐浴炉控制系统进行改造的方案。针对盐浴变压器只能进行无载分接、有级调节的问题，本方案采取在变压器原边串接晶闸管的方法，将手动转换的温度控制，即无载分接开关机械触点调节电压改为单片机自动控制晶闸管的导通，将手动控制温度改为PID控制，从而提高了控制精度，降低了工人劳动强度。
 针对盐浴炉的非线性、变参数、大时滞，工作环境差，加工零件多样的特点，本方案控制器采用PID控制算法。本文提出的PID控制算法。主要由数字PID调节构成。PID控制算法提高了系统的自适应能力和鲁棒性，获得了较好的控制稳定性。还实现了生产过程参数的自动显示和记录、超温报警、工件入炉、出炉提示等辅助控制功能。节约了维修时间和费用。系统投入使用后，提高了产品质量；节省了能源。

关键词：盐浴炉  PID控制  MPU

Abstract        
                                  
   Today, salt-bath stove is still one of the main heating equipments in the heat-treating workshops. The sale-bath stove employs presently generally adopt the backward method of gearshift adjusting and segment heat controlling. These methods of controlling consume too much power. It also has other demerits such as low precision and much noise. The voltage is manually regulated by non-load machine switch, which is apt to be burnt. As a result, frequent fixing is inevitable; moreover, these methods of controlling cannot meet the needs of processing certain work pieces.
   I this paper, transform approach is proposed for the salt-bath stove controlling system. In the
Approach, non-load machine switch is replaced by SCR controlled by MPU to regulate the temperature. This control precision is greatly improved, and at the same time parameters can be automatically stored and displayed during the manufacturing process, it also included some other auxiliary controlling functions, such as over-temperature alarm, work piece input or output reminding, etc. 
 The fuzzy PID control algorithm consists of fuzzy control and digital PID adjustment. The fuzzy controller can adjust the parameter of PID controller on line. The combination of fuzzy control and PID control would achieve fine function. The result of simulation and experiment show that the reformed automatic control system can gain upon higher product quality, less power consumption, less fixing time and expense, etc.
 
 
Keywords: Salt-bath stove   PID control   Micro-process Unit

目  录

第一章 概述…………………………………………………………………………1
第二章 方案论证……………………………………………………………………2
第三章 高温盐浴炉控制系统的硬件设计…………………………………………5
3.1现场环境介绍……………………………………………………………………5
3.2总体设计…………………………………………………………………………5
3.3控制系统结构……………………………………………………………………5
3.4元器件选择………………………………………………………………………6
3.4.1 热电偶…………………………………………………………………………6
3.4.2 A/D转换器 ……………………………………………………………………7
3.4.3 89C51单片机 …………………………………………………………………11
3.4.4LED显示部分 …………………………………………………………………18
3.4.5 控温电路………………………………………………………………………21
第四章 高温盐浴炉PID算法………………………………………………………25
4.1数字控制…………………………………………………………………………25
4.2数字PID控制算法………………………………………………………………26
第五章 高温盐浴炉软件设计………………………………………………………28
5.1芯片间的通讯方式………………………………………………………………28
5.2 控制系统软件设计 ……………………………………………………………28
5.2.1 主程序…………………………………………………………………………28
5.2.2 子程序…………………………………………………………………………29
第六章 系统抗干扰的设计…………………………………………………………33
致谢………………………………………………………………………………… 34
参考文献…………………………………………………………………………… 35
附表一………………………………………………………………………………36
附表二………………………………………………………………………………37
附表三………………………………………………………………………………