过程变量英语

In a production process, the most common variables are temperature, flux,and liquid level. Among them, temperature is very important. The control of temperature of conduction oil, working as a medium in heatng process determines the quality and efficient. This paper focuses on the desin of conduction oil temperature-control system(COTCS). This paper has analized the operating principle of COTCS, and adopted the Selective Control of Conduction Oil and Stem Flow program according to the requirement. In this program, WZPB temperature transmitter and JY-LUGB flow transmitter are used for flow and temperature collection, and finalize the selective control. AT89S52 SCM is applied as central controller to monitor the steam flow and temperature and send the data to SCM for analyzing after beening transvered by AD. Final signal will be used for adjusting the valve according the value sent bt AD. The control process can be completed by PID. Adoption of CAN in system enables the communication between upper computers and the keyboard setting, display and alarm at the same time. the context has expounded deep the control process to make manoeuvre possible.By upgrading this system to a more efficient, statable, reliable, accurate level has a significant contribution to the industrial control. 希望采纳和加分，给鼓励，因为对术语的不熟悉，可能错误，忘理解。

PID 控制器简介PID 控制器可以独立控制器 （也称为单回路控制器）、 可编程控制器中的控制器、 嵌入式的控制器或在 Visual Basic 或 C# 的计算机程序软件。PID 控制器是过程控制器具有以下特点：_Continuous 过程控制_Analog 输入 （也称为"测量"或"过程变"或"光电"_Analog 输出 （简称为"输出"）_Setpoint (SP)(P) _Proportional、 (一) 的积分和/或 Derivative(D) 常数"连续过程控制"的例子有温度、 压力、 流量和级别的控制。 例如控制一罐的加热。 对于简单的控件，您必须两个温度限制传感器 （低和一个高），然后切换加热器低温度限制传感器开启时，然后打开关闭时温度上升到高温度限制传感器加热器。 这是类似于最家庭空调科技加热恒温器。在相反 PID 控制器将接收实际温度作为输入，并控制调节的加热器气体流动的阀门。 PID 控制器自动查找气体加热器保持温度稳定，给定的正确 (恒定的) 的流。 而不是，两个点之间的来回蹦蹦跳跳的温度，温度是保持平稳。 如果在给定降低，然后 PID 控制器将自动减少流向加热器的气体的数量。 如果在给定引发，然后，控制器将自动增加流向加热器的气体的量。 同样，控制器会自动热、 阳光天 （当它是热外加热器） 和冷。 云几天。模拟输入 （测量） 称为"流程变量"或"光电"。 您想要一个高度精确的迹象，表明您正试图控制的工艺参数 PV。 如果您要保持的温度的示例为 + 或 – 一个程度，然后我们通常争取最少十倍，或某种程度的十分之一。 我 f 模拟输入是 12 位模拟输入和传感器的温度范围是 0 到 400 度，然后我们"理论上"的精度计算将 400 度除以 4096 （12 位） = 0.09765625 度。 [1] 我们说"理论上"，因为它假设有没有噪音和我们的温度传感器、 布线和模拟转换器中的错误。 有其他假设线性等。 在点被-1/10 的一个程度"理论上"精度甚至通常所用的噪音和其他问题一程度的准确性轻松地应身心健康。模拟输出往往只是被称为外放。 通常这给定为 0 ~ 100%。 在加热本例中，这将意味着阀门是全封闭 (0%) 或完全打开 (100%)。.

In industrial production, temperature, flow, pressure and liquid level is the most common industrial production process variables. Among them, the temperature is a very important process variables. In industrial production, heat conduction oil as heat transfer medium industrial heating process, the temperature control of the quality of high and low, will directly affect the quality of the products and production efficiency. This article mainly thermal oil temperature control system design.This paper analyzes the working principle of the thermal oil temperature control system, and according to the technological requirements, using the choice of thermal oil temperature and steam flow control solutions. This design adopts the WZPB - 230 temperature transmitter, JY - LUGB flow transmitter to collect temperature and flow rate, and complete the selection of actuators. The monitoring system of AT89S52 single chip microcomputer as the system core controller, to test the steam flow and heat conduction oil temperature, and the detecting data transmitted to the microcontroller through the AD converter, by single-chip microcomputer for data processing and analysis. Corresponding control signal output to the DA converter, according to the size of the DA converter output value control of valve opening, control is accomplished by PID control algorithm. System adopts CAN bus to realize the communication between upper machine and production device. At the same time, this design has realized the keyboard Settings, display, alarm, etc. This paper carried on the thorough analysis of the system control process, finally realizes the good control of thermal oil temperature.By improving the system control scheme thermal oil temperature control system has fast response, good stability, high reliability, good control precision, has played a significant realistic meaning in industrial control Have the practical significance.