随着DCS(Distributed Control System,分散控制系统)在大型火电机组的广泛应用,使大屏报警设置非常方便,但报警设置随意、报警数量不合理、参数配置不当、逻辑混乱已成为大屏报警的普遍现象,给运行人员监盘带来较大压力,威胁机组安全稳...随着DCS(Distributed Control System,分散控制系统)在大型火电机组的广泛应用,使大屏报警设置非常方便,但报警设置随意、报警数量不合理、参数配置不当、逻辑混乱已成为大屏报警的普遍现象,给运行人员监盘带来较大压力,威胁机组安全稳定运行,电厂发生报警不及时导致的事故扩大现象偶有发生。本文介绍了大屏报警的设计要求,阐述了大屏报警逻辑及画面的设计方法,描述了项目实施过程的注意事项,通过实施大屏报警分级优化,使报警画面清晰可靠,大大降低了运行监盘压力,该方案可供同类型电厂参考。展开更多
Active screen plasma nitriding (ASPN) is a novel nitriding process, which overcomes many of the practical problems associated with the conventional DC plasma nitriding (DCPN). Experimental results showed that the meta...Active screen plasma nitriding (ASPN) is a novel nitriding process, which overcomes many of the practical problems associated with the conventional DC plasma nitriding (DCPN). Experimental results showed that the metallurgical characteristics and hardening effect of 722M24 steel nitrided by ASPN at both floating potential and anodic (zero) potential were similar to those nitrided by DCPN. XRD and high-resolution SEM analysis indicated that iron nitride particles with sizes in sub-micron scale were deposited on the specimen surface in AS plasma nitriding. These indicate that the neutral iron nitride particles, which are sputtered from the active screen and transferred through plasma to specimen surface, are considered to be the dominant nitrogen carrier in ASPN. The OES results show that NH could not be a critical species in plasma nitriding.展开更多
为解决分散控制系统(distributed control system, DCS)无法精确测量汽轮机阀门关闭时间、人工采用示波器测试汽轮机阀门关闭时间工作量大等问题,设计了高速数据同步采集模块对阀门位置反馈信号进行定时采集记录,编写专用软件对采集的...为解决分散控制系统(distributed control system, DCS)无法精确测量汽轮机阀门关闭时间、人工采用示波器测试汽轮机阀门关闭时间工作量大等问题,设计了高速数据同步采集模块对阀门位置反馈信号进行定时采集记录,编写专用软件对采集的数据标记时间标签并进行转换、校准和筛选,从采集的数据中精确筛选出阀门离开全开位置和到达全关位置的时刻等关键数据,由通信模块送DCS控制器进行处理并判断各阀门关闭时间是否合格。实践表明,所设计的数据采集模块及数据处理软件与现有DCS结合,能实现汽轮机阀门静态关闭时间的自动测量、计算和结果判定,测试结果准确性和便捷性优于人工使用示波器测量。展开更多
文摘随着DCS(Distributed Control System,分散控制系统)在大型火电机组的广泛应用,使大屏报警设置非常方便,但报警设置随意、报警数量不合理、参数配置不当、逻辑混乱已成为大屏报警的普遍现象,给运行人员监盘带来较大压力,威胁机组安全稳定运行,电厂发生报警不及时导致的事故扩大现象偶有发生。本文介绍了大屏报警的设计要求,阐述了大屏报警逻辑及画面的设计方法,描述了项目实施过程的注意事项,通过实施大屏报警分级优化,使报警画面清晰可靠,大大降低了运行监盘压力,该方案可供同类型电厂参考。
文摘Active screen plasma nitriding (ASPN) is a novel nitriding process, which overcomes many of the practical problems associated with the conventional DC plasma nitriding (DCPN). Experimental results showed that the metallurgical characteristics and hardening effect of 722M24 steel nitrided by ASPN at both floating potential and anodic (zero) potential were similar to those nitrided by DCPN. XRD and high-resolution SEM analysis indicated that iron nitride particles with sizes in sub-micron scale were deposited on the specimen surface in AS plasma nitriding. These indicate that the neutral iron nitride particles, which are sputtered from the active screen and transferred through plasma to specimen surface, are considered to be the dominant nitrogen carrier in ASPN. The OES results show that NH could not be a critical species in plasma nitriding.
文摘为解决分散控制系统(distributed control system, DCS)无法精确测量汽轮机阀门关闭时间、人工采用示波器测试汽轮机阀门关闭时间工作量大等问题,设计了高速数据同步采集模块对阀门位置反馈信号进行定时采集记录,编写专用软件对采集的数据标记时间标签并进行转换、校准和筛选,从采集的数据中精确筛选出阀门离开全开位置和到达全关位置的时刻等关键数据,由通信模块送DCS控制器进行处理并判断各阀门关闭时间是否合格。实践表明,所设计的数据采集模块及数据处理软件与现有DCS结合,能实现汽轮机阀门静态关闭时间的自动测量、计算和结果判定,测试结果准确性和便捷性优于人工使用示波器测量。
