设计说明书 电阻炉温度控制系统.pdf

摘 要 电阻炉是一种利用电流流经电阻体产生的热量来进行加热或熔化物料的电炉。电 阻炉被广泛地应用在冶金、化工等行业。它对炉温控制的要求较高，炉温控制的好坏 将直接影响到产品质量以及生产效率，因此电阻炉的炉温控制在工业生产、科学研究 中都具有重要的意义。 本设计利用单片机来作为数据处理与控制单元，电阻炉作为被控对象，以热电偶 作为测温元件，用晶闸管作为输出控制元件来实现对电阻炉温度的自动控制。本系统 利用 K 型热电偶温度传感器，把实时检测到的炉温的信号送入 MAX6675 芯片中，经 过信号放大等一系列转换处理以后，再将信号送到单片机 STC89C52 内进行 PID 运 算，同时系统具有超限声光报警功能，并且能通过按键设置温度的上下限。经 PID 运 算后，将控制信号输出，调节晶闸管导通角进行温度控制，同时 LCD 液晶显示器能 显示温度值，使电阻炉的炉温始终保持在设定范围内。本设计根据系统的需要，设计 了硬件电路并详尽的介绍了组成硬件电路各个部分；根据各部分软件流程图编写了软 件程序。 关键词： 电阻炉； 单片机； MAX6675； PID控制 Abstract Resistance furnace is a furnace which uses the heat generated by the current flowing through the resistor for electric heating or melting materials. Resistance furnace is widely used in metallurgy, chemical and other industries. It demands a higher temperature control, temperature control will directly affect the quality of product and the efficiency of production ，therefore resistance furnace temperature control are of great importance in industrial production and scientific research. This design uses a single-chip as a data processing and control unit, resistance furnace as the controlled object. The system uses a K-type thermocouple to as temperature measurement devices and uses the thyristor as control components to achieve the control temperature of the resistance furnace.The system uses K-type thermocouple temperature sensor，it sends the furnace temperature signal detected by sensor into MAX6675 chip,and after the signal is through a series of conversion process such as amplified. Then the signal will be sent to the single-chip STC89C52 to do a PID operation.System also has overrun sound and light alarm, and can through the upper and lower buttons to set the temperature limit.After the PID operation,