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屠珊 《工业仪表与自动化装置》2006,(1):18-20
由于阀内流体流动强烈的非定常性而影响阀门工作的稳定性,甚至引起阀门的振动,危及设备的安全运行.以调节阀为研究对象,利用微小型高频动态压力传感器及其采集系统,在阀座喉部、阀碟头部等阀体内各关键部位设置测点,进行多种工况和多个方位的试验研究,并利用频谱分析方法对调节阀杆振动或不稳定工况的流场动态压力信号进行采集、处理和分析,深入研究阀内的复杂流动特性及其对阀门工作稳定性的影响,得出相应结论. 相似文献
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研制了一种采用CMOS工艺和表面牺牲层技术加工的微热板式低气压传感器.该微热板为四臂支撑悬空矩形板,其边长为75μm,支撑桥长为60μm,板下气隙高度为0.5μm.采用经典傅里叶传热理论分析了恒电流工作方式下气压对微热板瞬态和稳态热特性的影响,结果表明在低气压范围内微热板传热以支撑桥导热为主,气压较高时以气体导热为主,微热板加热功率随气压增加而减小;传感器的热响应时间为毫秒量级并随气压增加而减小.传感器采用恒电流工作方式时,测得其气压响应范围为1~10~5Pa,且加热功率与气压间关系的理论分析结果与实测值吻合得较好. 相似文献
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Modern primary distribution substations often adopt SF6 gas insulated switchgears (GISs) to reduce the overall construction space. Traditional current transformers (CTs), which are generally used in GISs for current measurement, consist of magnetic cores. These cores are bulky and increase the minimum space required inside GISs. Moreover, the occurrence of faults causes saturation in traditional CTs; this leads to distortion of detected current waveforms, which in turn triggers false responses in protective systems. The recently proposed power current microsensors based on the Hall effect have many advantages over traditional CTs, including smaller volume, quicker response, and wider measurement range, and they do not face the above-mentioned saturation problem. This study assesses the feasibility of replacing traditional CTs inside GISs with power current microsensors, taking into account certain actual conditions, including: (1) the actual distance between two adjoining cables inside GISs, (2) the worst unbalanced three-phase loads allowed by typical primary distribution substations, and (3) the four most common faults occurring in primary distribution substations. Current simulation and measurement results show that power current microsensors can measure current as accurately as traditional CTs. Moreover, during faults, microsensors do not encounter problems related to saturation, which exist with traditional CTs. 相似文献
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无线网络化微传感器及其嵌入式系统 总被引:2,自引:3,他引:2
首先对无线传感网络作了分类,描述了无线网络化微传感器的体系结构,提出了两种蓝牙无线网络化传感器的体系结构,其主要特征是蓝牙、RF-MEMS天线及嵌入式系统.然后,讨论了无线网络化微传感器的技术要求与关键技术,包括自适应跳频与自配置蓝牙组网等新思想;研究重点在于无线通信的稳定性与可靠性、无线组网方案及实时互联网连接.为实现环境监测并通过无线网络通信传递测量值,可设计无线网络化微传感器嵌入式系统;选用了适当型号的嵌入式处理器和uClinux操作系统,设计了系统软件、低层驱动程序、调度程序及蓝牙高层协议程序.最后,以无线远程图像监视系统作为实例加以说明. 相似文献
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目前,铂电阻温度传感器主要应用于73 K(-200℃)以上环境的温度检测。设计了可用于10 K(-263℃)~200 K(-73℃)低温区的铂电阻温度微传感器。铂电阻温度微传感器采用对称的折回型结构,这种结构有效地降低了交流感抗的影响。传感器的敏感薄膜是一层采用磁控直流溅射沉积厚度为200 nm的铂薄膜。采用QD PPMS仪器测试传感器的电阻与温度的变化关系,得出传感器的电阻温度系数(TCR):研制的温度传感器的电阻温度系数在温度高于30K(-243℃)时可达到9980×10-6/K,同时在低于30K(-243℃)的深低温区域TCR也可达到3730×10-6/K。 相似文献