压力变送器的过程诊断技术设计与实现

Functional safety self-diagnosis of intelligent pressure transmitter

随着工业自动化技术的发展,安全仪表系统广泛应用于保障设备安全运行,避免安全危险事故发生.作为安全仪表系统的重要组成部分,仪器仪表的安全性成为保障系统高可靠性的一个重要环节。过程诊断技术检测压力变送器的过程压力,以及当过程中的其它设备或者变送器安装环境发生改变时所造成的过程压力的改变。该技术的实施首先需要在正常条件下对过程的噪声特征进行数学建模,比如统计平均数,标准差或者变异系数。然后,将建好的模型作为基线,对随时变化的当前过程压力进行分析与处理。如果发现当前值发生显著变化,变送器会根据用户的配置产生通信警报或者模拟警报,并记录警报产生时的时间戳,同时警报标识在人机交互界面进行显示。统计值也可以作为第二主变量通过通信进行传送,用户可以通过分析过程噪声特征对整个过程系统进行管控,也可以直接通过第二变量生成自己的警报信息。

With the development of industrial automation technology,the safety instrumented system is widely used to ensure the safe operation of equipment and avoid the occurrence of safety hazards.As an important part of the safety instrumented system,the safety of the instrumentation has become an important link to ensure the high reliability of the system.Process diagnostics technology detects the process pressure of the pressure transmitter,as well as changes in process pressure caused by changes to other equipment in the process or the environment in which the transmitter is installed.The implementation of this technique first requires mathematical modeling of the noise characteristics of the process under normal conditions,such as statistical mean,standard deviation or coefficient of variation.Then,the built model is used as the baseline to analyze and process the current process pressure that changes at any time.If it is found that the current value has changed significantly,the transmitter will generate a communication alarm or an analog alarm according to the user's configuration,and record the time stamp when the alarm is generated,and the alarm logo will be displayed on the human-machine interface.Statistical values can also be transmitted through communication as the second primary variable.Users can manage and control the entire process system by analyzing process noise characteristics,or generate their own alarm information directly through the second variable.