恒温箱PLC控制系统毕业设计

摘要

随着现在电子技术的发展，温度测量的利用在许多地方都有比较大的发展空间，许多质量好而且便宜的温度传感器被设计开发，在温度检测控制和测量方面得到了较大的应用。例如在日常生活、工业生产、和实验室当中恒温箱的的应用随处可以见到。在生活中我们用恒温箱保存食物，在工业生产中一些原料的保存用到恒温箱，实验室里特别是生物的培养实验室恒温箱的应用更为广泛。除此之外，在医用、水产、特种工业、工业探伤、照相等领域，都需要稳定而精确的温度。与此同时随着社会的发展，温度、压力、液位和流量是四中最常见的过程变量，其中温度是一个非常重要的过程变量。因此国内外对恒温箱的研究越来越深入，恒温箱的用途也越来越广泛，恒温箱plc控制系统不仅不仅促进了科技的发展和工业生产，也提高了人民的生活水平，因而这种低成本而又能打成需求者需要的恒温箱就有意义。

本次设计中，恒温箱控制系统的性能在很大程度上取决于对温度的控制性能，与此同时采用以PLC为主控制器通过拨码开关设定初始输入温度，设定温度与所测温度进行比较，然后plc对数据进行处理，根据偏差信号的大小来驱动控制发热丝或冷水泵，从而使恒温箱达到温度恒定控制的目的。本次恒温箱plc控制系统将基于plc设计完成，设计过程当中将应用的温度传感器、数码显示管、加热装置、冷却水泵、冷却器、储水箱、温度显示、阀门及状态指示不见。恒温箱plc控制系统要求控制恒温箱的水温在20~80摄氏度之间某设定数值，当水温小于设定值时，采用电热升温。当水温大于设定值时，放出热水部分，并且启动冷却风扇使水流经冷却器向恒温箱提供水。本恒温箱plc控制系统以plc控制器为核心，同时本系统也应用了温度传感器、流量传感器、和液位传感器，设计恒温箱plc控制系统的硬件电路和软件程序，完成控制任务。恒温箱plc控制系统的设计还对plc特殊功能扩展模块和BCD译码器做了简单的介绍。

关键词：PLC，传感器，恒温箱，PID

Abstract

With the current development of electronic technology, the use of temperature measurement in many places has a relatively large space for development, a number of good quality and inexpensive temperature sensor is designed and developed, in terms of temperature measurement and control and measurement applications have been larger. For example, in daily life, industrial production, and laboratory applications among the incubator can be seen everywhere. In life we saved with the thermostat food, some preserved in the industrial production of raw materials used in the oven, in particular the application of biological laboratory culture laboratory incubator is more extensive. In addition, the medical, aquatic products, specialty industrial, industrial inspection, photography and other fields, we need a stable and precise temperature. With the development of society at the same time, temperature, pressure, level and flow are the four most common process variables, where the temperature is a very important process variables. So researches on more in-depth incubator, incubators use has become increasingly widespread, incubators plc control system not only has not only promoted the development of technology and industrial production, but also improve the living standards of the people, so this demand for low cost and they can be labeled as an incubator needs to be meaningful The design, performance thermostat control system largely depends on the temperature control performance, at the same time adopt a PLC-based controller to set the initial input temperature via DIP switch, set temperature and the measured temperature comparison, then plc for data processing, based on the size of the error signal to the drive control heating wire or cold water pump, so that the oven temperature constant control purposes. The incubator will be based plc control system design is completed, the design process will be applied temperature sensors, digital display tubes, heating devices, cooling water pumps, coolers, storage tanks, temperature display, valves and status indication disappear. Plc thermostat control thermostat control system requires a set value of temperature between 20 to 80 degrees Celsius, when the water temperature is less than the set value, the use of electric heating. When the water temperature is greater than the set value, the release of hot water portions, and start the cooling fan to provide cooling water to flow through the incubator. The thermostat control system plc controller as the core, but also the application of the system temperature sensors, flow sensors, and liquid level sensor, design incubator plc control system hardware and software programs, complete control tasks. Design incubator plc control system also plc expansion modules and special function BCD decoder to do a simple introduction.

Abstract: PLC, sensors, thermostat，PID