恒温箱的设计.doc

江 西 理 工 大 学 本 科 毕 业 设 计（论文） 题 目：恒温箱的设计 专题题目： 学 院：电气工程与自动化学院 专 业：自动化 班 级：自动化083 学 号： 学 生：师 指导教师： 梁毓明 职称：讲师 指导教师： 职称： 时间：2012年5月29日 摘 要 恒定温度的设备，被广泛地应用于生产、生活、实验等领域。在医用、水产、特种工业、工业探伤、照相等行业，都需要有稳定而精确的温度。在本设计中，通过对恒温箱温度的检测与变送传到PLC，与给定值进行比较，PLC对数据进行处理，根据偏差信号的大小驱动控制发热丝或冷水泵，从而达到恒温箱内温度恒定控制的目的。 本次恒温箱系统将基于PLC设计完成。设计过程中将应用温度传感器、数码显示管、加热装置、冷却水泵、冷却器、储水箱、温度显示、阀门及状态指示部件。恒温系统要求控制恒温箱水温在20～80℃之间的某个设定数值。两个数码显示管分别用于显示设定温度及显示测试温度。当水温低于设定值时，采用电加热升温。当水温高于设定值时，放出部分热水，启动冷却水泵使水流经冷却器向恒温箱供水降温。本系统以PLC控制器为核心，设计控制系统的硬件电路和软件程序，完成要求的控制任务。 关键词：恒温箱；PLC；传感器 ABSTRACT Constant temperature equipment is widely used in the production, life, and experiments. In the medical, aquatic products, specialty industrial, industrial radiography, photographic and other industries, need to have a stable and accurate temperature. In this design, through the detection and transmission of the incubator temperature to the PLC, compared with a given value, the PLC for data processing control of the heating wire or cold water pump drive according to the size of the deviation signal to achieve the incubator a constant temperature control. The incubator systems, PLC based design. Design during application of temperature sensor, digital display tube, the heating device, cooling water pumps, coolers, storage tanks, temperature display, valves and status indicator components. The thermostat system requirements to control the water temperature of the incubator to a set value in the range of 20 ~ 80 ℃. Two digital display tubes were used to display the set temperature and display the test temperature. When the water temperature below the set value, the electric heating to heat up. When the water temperature is higher than the set value, to release some hot water, and start the cooling water pump so that flow through the cooler cooling water supply to the incubators. This system as the core of the PLC controller, the design of control systems hardware and software program to complete th