共查询到19条相似文献,搜索用时 180 毫秒
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旋进旋涡流量计是对气体介质流量进行计量的理想仪表。在我厂空分空压站的设计中 ,选用了 4台LUXZ型旋进旋涡智能流量计。1 测量原理如图 1所示 ,在流量计传感器入口处 ,安装有一固定的旋叶。该旋叶类似于涡轮流量计的涡轮 ,但并不在流量计内旋转。它的作用是当流体进入流量传感器时 ,在旋叶的作用下强迫流体进入旋转运动 ,从而产生一旋涡流。传感器内部为锥形 (类似文丘里管 ) ,当涡流旋进到达收缩段时突然节流而使旋涡流加速。旋涡流的频率与介质流速成正比 ,并且为线性。在传感器收缩口处安装有一个压电传感器 ,可检测出涡流频率的… 相似文献
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本文主要分析了流体的涡漩运动特性,结合强度调制光纤的传感原理,和光纤的微弯损耗特性和多模光纤模式间干涉的结果,设计了一种同时测量流体的流量和密度的新型流量、密度计。该仪器通过光纤频率检测系统和光纤举力检测系统分别检测流体流过漩涡发生体产生的稳定漩涡发生频率f和流体作用在漩涡发生体上的升力。结合“卡门涡街”理论和茹科斯基升力定理计算出流体流量和稳定漩涡发生频率f的线性关系和流体密度与稳定漩涡发生频率f和流体作用在漩涡发生体上的升力的关系。并设计出同时检测漩涡频率f和升举力仪器的系统原理图。 相似文献
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脉动流场中旋进旋涡流量计流体振动特性的实验研究 总被引:6,自引:0,他引:6
研究了脉动流场中旋进旋涡流量计流体振动特性。在自行设计的实验装置中使用压电式压力传感器对50mm口径的旋进旋涡流量计在脉动干扰流场中的流体振动特性进行试验研究,明确了流体脉动对旋进旋涡效应的影响因素。实验研究表明,流体脉动干扰与旋进旋涡效应的脉动压力为线性叠加关系;流体脉动干扰的能量耗散作用将导致旋进旋涡效应的衰减,从而扩展旋进旋涡流量计测量的下限。并提出了新的设计,以利用对称脉动压力信号差分处理和改善测量系统的电磁屏蔽性能来减弱流场波动对该类流量计的影响。 相似文献
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干气是石化行业重要的物料,对其进行准确计量具有重要意义。但其是典型的变组分气体,不能采用恒定组分气体质量流量的测量方法。推导式气体质量流量计,用涡街流量传感器测量工况条件下的体积流量,用旋涡发生体前后的压差计算流量计出口侧气体密度,经计算得到质量流量,从而解决了变组分气体质量流量测量难题。文章阐述了测量管内气体雷诺数影响校正、可膨胀性补偿,以及设计计算、计量检定方法和安装调试。实践表明,这种方法简单可靠,相比科氏力质量流量计可显著节省投资。 相似文献
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平衡流量计作为一种节能型的差压式流量仪表,凭借其特殊定制的传感器结构,对流体进行平衡整流,涡流最小化,形成近似理想的流体。并且它与孔板具有相同的使用方法和外形,在当今节能减排的社会形势下,很适合在能源计量中使用平衡流量计。 相似文献
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旋涡流量计是近年发展起来的新型流量仪表 ,它是根据流体振荡原理进行流量测量的 ,属于速度式流量计。目前已开始应用于液体、气体和蒸汽的流量检测。据介绍 ,在日本、欧美等国家 ,旋涡流量计的市场占有率呈逐年上升趋势 ,大有取代孔板之势。1 旋涡流量计的特点与其他流量计相比 ,旋涡流量计有如下特点 :( 1)其输出信号是与流速成线性关系的脉冲信号 ,不存在零点漂移问题 ,便于与计算机通讯。( 2 )结构简单 ,无可动部件 ,长期运行十分可靠。( 3)传感器不直接接触介质 ,性能稳定 ,寿命长。( 4 )压力损失小 ,运行费用低 ,具有节能意义。( 5 )… 相似文献
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旋进旋涡流量计的数值模拟研究 总被引:4,自引:4,他引:0
通过计算流体力学(CFD)的方法对50 mm口径的旋进旋涡流量计进行了数值仿真.分析了旋涡进动效应下流量计内部流场的演变情况,找出传感器最佳安装位置以减小外界振动与流体脉动噪声对旋进旋涡流量计造成的影响,并且在此基础上对旋进旋涡流量计进行改进——在旋进旋涡流量计前面加导流片.改进后的旋进旋涡流量计压力损失有了较大幅度的减少. 相似文献
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A composite optical bend loss sensor for measuring 3-D forces has been developed. The sensor is composed of two optic fiber meshes which are embedded into a polydimethylsiloxane (PDMS) slab. The sensor consists of an array of optical fibers lying in perpendicular rows and columns sandwiched inside an elastomeric pad. A map of normal and shear stress is constructed based on observed macrobending through the intensity attenuation from physical deformation of two adjacent perpendicular fibers. Due to the new addition of the composite design and acrylic holder, the stability of the present sensor is found to be significantly better than our previously reported microfabricated optical bend loss sensor. In this paper, we will report the results of an optical bend loss simulation using the beam propagation method based on a series of images captured by a CCD camera on the fiber's bending curvatures. The result from the simulation will be compared with the results obtained from the experiment. Other results include vertical force and shear measurements at a single pressure point of the sensor. A force image algorithm is used to map the force distribution detected by the sensor. Here, we will present the results of six different shape patterns and two force magnitudes on each shape using a neural network system. We will also present a radio frequency sensor module, which we developed for the composite optical bend loss sensor for remote sensing. 相似文献
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A fiber optic ultrasonic system is described which monitors the cure of an epoxy resin. Ultrasound is generated using a high-power
optical fiber to deliver high-energy pulses of light to the prepared surface of an aluminum mold that contains the curing
epoxy resin. The generated ultrasound is detected using a local fiber optic ultrasound sensor embedded in the curing epoxy
resin. The system was used to measure the ultrasonic signal velocity and ultrasonic attenuation throughout the cure of a neat
epoxy resin at room temperature. Similar measurements also were performed using a piezoelectric transducer for ultrasound
generation and an embedded fiber optic sensor for detection, which provided verification of the results using the complete
fiber optic system. The complete fiber optic system demonstrated adequate sensitivity throughout the entire cure to measure
the ultrasonic signal velocity and ultrasonic attenuation. 相似文献
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大型结构应变场光纤分布监测系统 总被引:10,自引:2,他引:8
研究了一种用于大型工程结构应变、变形状态监测的基于光时域反射技术的分布式光纤应变传感系统。设计了一种新型的光纤微弯传感器结构,用于对沿传感光纤分布各测量点的应变信息进行提取;在此新结构的基础上,了全光纤型应变传感器串行阵列,以对构件应变测量和安全监测为主要目标,建立了起了分布光纤应变实时监测系统,进行了系统实验了得到了良好的结构。 相似文献
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高抗干扰性能涡街流量计传感器的研究 总被引:1,自引:1,他引:1
针对涡街流量计抗干扰性能差的缺点,设计了一种新的传感器结构———悬浮式差动传感器,使流量计一次仪表输出信号的信噪比大大提高.实验结果表明,采用此种传感器结构的涡街流量计的抗干扰性能得到显著改善. 相似文献
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基于小波滤波器组的涡街流量计信号处理方法 总被引:2,自引:0,他引:2
涡街流量计应用比较广泛,但是,由于易受管道振动和流场不稳定等因素干扰,如何从强噪声背景下检测出涡街信号频率,一直是个难题.研究了多相结构ⅡR小波滤波器组的设计方法,给出了Butterworth型小波滤波器组的实现方案,将基于小波滤波器组的信号处理方法应用于涡街流量计,并给出最佳频带的判别准则.仿真结果表明,Butterworth型小波滤波器组具有较好的幅频特性和较高的频率精度. 相似文献
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Kim JA Kulkarni A Kang J Amin R Choi JB Park SH Kim T 《Journal of nanoscience and nanotechnology》2012,12(7):5381-5385
Graphene is a zero band-gap semi-metal with remarkable electromagnetic and mechanical characteristics. This study is the first ever attempt to use graphene in the surface plasmon resonance (SPR) sensor as replacement material for gold/silver. Graphene, comprised of a single atomic layer of carbon, is a purely two-dimensional material and it is an ideal candidate for use as a biosensor because of its high surface-to-volume ratio. This sensor is based on the resonance occasion of the surface plasmon wave (SPW) according to the dielectric constants of each metal film and detected material in gas or aqueous phase. Graphene in the SPR sensor is expected to enlarge the range of analyte to bio-aerosols based on the superior electromagnetic properties of graphene. In this study, a SPR-based fiber optic sensor coated with multi-layered graphene is described. The multi-layered graphene film synthesized by chemical vapor deposition (CVD) on Ni substrate was transferred on the sensing region of an optical fiber. The graphene coated SPR sensor is used to analyze the interaction between structured DNA biotin and Streptavidin is analyzed. Transmitted light after passing through the sensing region is measured by a spectrometer and multimeter. As the light source, blue light which of 450 to 460 nm in wavelength was used. We observed the SPR phenomena in the sensor and show the contrary trends between bare fiber and graphene coated fiber. The fabricated graphene based fiber optic sensor shows excellent detection sensitivity of the interaction between structured DNA and Streptavidin. 相似文献
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反射式光纤传感器光纤对输出特性的数学模型 总被引:11,自引:0,他引:11
从反我纤传感器中最基本的光纤对入手,以光度学原理为基础,建立了该传感器在镜反射时的输出特性数学模型。在此模型的基础上,利用计算机给出了光纤传感器输出特性的仿真结果并进一步讨论了输出特性与各参数之间的关系。 相似文献