新型气体涡街流量变送器设计

设计了一种新型气体涡街流量变送器以简化测量系统结构,改善测量性能。变送器由信号测量单元与信号处理单元组成,测量单元同时对漩涡频率、被测气体温度和压力进行检测,信号处理单元以单片机为核心,通过软件对流量测量信号进行温度、压力补偿和非线性修正等处理以减少测量误差。实验测试结果表明:变送器性能指标达到了设计要求。     

基于流量分析仪校准的流量自动调节技术研究

基于汽油车简易瞬态工况法用流量分析仪（以下简称流量分析仪）流量示值误差校准,该文提出了一种用于流量分析仪校准的气体流量自动调节方法。通过人机接口设置气体标准流量值,根据实验推出的流量值-流量调节气门角度关系,驱动机构驱动流量调节气门转动至设定流量值所对应的预置角度进行粗调,而后根据流量调节装置的流量计检测值,驱动机构驱动流量调节气门转动进行微调,直至流量计检测值为设定流量值,从而根据设定流量值完成对流量分析仪的校准。     

亚硝胺化学发光检测系统气体流量控制器设计

微小流量气体的质量流量控制是亚硝胺化学发光检测的重要组成部分,气体流量的控制精度对检测结果有重要影响。文中根据反馈控制的原理,采用微型电磁比例阀、流量传感器、数字控制电路和PID算法搭建了一套适用于微小流量场合的气体流量控制装置。设计了比例阀的驱动电路,传感器的信号调理电路,微控制器电路,针对被控对象的特性对控制算法进行了优化。测试结果显示,流量控制的精度优于±0.05ml/min(标准状况下),调节时间小于2s,基本无超调。且由于采用反馈控制,具有较好的抗干扰性能。该装置使用方便,成本低,具有一定的实用价值。     

LWGQ气体涡轮流量传感器

LWGQ型气体涡轮流量传感器是一种高精度的气体流量传感器,可解决多种流量计无法测量的气体小流量。它与相应的信号转换器结合可实现流量信号的传输,与相应的流量积算仪相配可实现瞬时流量和累积流量的显示与控制。广泛用于石油、化工、冶金、科研等领域的一般气体、天然气、煤气等气体计量与控制系统。     

卟啉传感器气体检测系统流量控制研究

针对目前卟啉传感器气体检测系统中采样气体流量控制的不足,提出了一种控制精度高、响应速度快、超调量小的流量控制系统。该系统利用增量式PID算法调整PWM脉冲信号的占空比,从而间接地改变直流电机两端电枢电压的大小,实现对采样气体流量的控制。流量控制精度为±1.5 cm3/min,且气体流量仅需15.6 s就能达到稳定。实验结果表明:控制采样气体流量,有助于卟啉传感器气体检测系统准确、快速地实现对目标气体的检测。     

LUGB系列涡街流量变送器的检测放大器

介绍了ＬＵＧＢ系列涡街流量变送器的核心部件－检测放大器的电路分析。主要论述了该流量变送器的测量原理及检测放大器的电路组成与工作原理。通过实际应用证明：该检测放大电路在测量范围测量精度上都达到了一定的要求。     

微气体流量传感器

介绍了一种硅微桥结构热式流量传感器的结构和工作原理。采用单片机对传感器的输出信号进行处理，构成一个完整的测试系统，使系统具有定时、定量、测量、非线性补偿等功能。     

基于8098的高精度标准气体流量测控仪

研究了利用涡街流量计和 80 98单片机设计高精度标准气体流量测控仪的方法。介绍了测控仪的硬件组成原理、测控电路以及软件功能和流程。实际运行结果表明 ,该系统具有结构简单、功能完善、测控精度高、抗干扰能力强等特点。     

用阻抗分析仪测试传感器

利用阻抗分析仪测试某些传感器,为传感器的分析,设计提供可靠、有效的数据。     

涡街流量传感器应用问题的探讨

提出了涡街流量传感器在使用中存在的各种问题,介绍电容检测式涡街流量传感器工作原理及性能,展望涡街流量传感器的应用前景.     

Gas flow meter for application in medical equipment for respiratory control: study of the housing

The study of the housing of a gas flow meter for use in medical equipment for respiratory control will be presented in this paper. The sensor is of the thermal type with dimensions 1.4 mm×0.9 mm. The housing is developed so as to assure conditions of laminar flow in a flow range from −200 to +200 standard liters per minute (SLPM). An analytical approach is first used to determine the main housing configuration. The type and the position of a bypass tube, which is fixed to the main flow tube, are studied in detail. Extensive simulations of the flow in different housing configurations and different conditions at the inlet and outlet of the housing were performed, using the finite element analysis (FEA) software package ANSYS. The optimum housing was finally fabricated and evaluated in oxygen flow. Excellent agreement of experimental results with simulation was obtained.     

MEMS气体流量传感器的简易流量测试装置

为了完成所研制的MEMS气体流量传感器样品的流量测试与标定,设计制作了一种由标准流量发生器和传感器信号读出与数据采集电路组成的简易流量测试装置。标准流量发生器由注射器和可更换的砝码组成,利用不同的砝码配重,在注射器出气口产生合适的恒定气体流速。通过理论分析和Ansys有限元数值仿真,验证了简易标准流量发生器的可行性。传感器信号读出与数据采集电路基于内建多路A/D转换器的单片机实现,具有传感器加热电阻器的恒温控制、流量信号的数字检测和显示的功能。采用该简易流量测试装置对自行研制的MEMS气体流量传感器进行了流量测试与标定,获得了待测器件的标定参数、传感器流量测量的绝对误差和相对误差。     

工业零件视觉检测系统中标定设备的误差分析

提出了一种简单、易于操作的自动标定设备,CCD摄像机可以在转盘旋转过程中,根据需要灵活的改变Z、Y、ω这三个自由度。并通过理论推导和实验验证了此自动设备的稳定性与可靠性。     

天然气压气机械设备故障信号时频分析特征提纯

天然气压气站压气机械设备工作环境恶劣,故障多发,而机械设备的故障状态下的振动噪声信号是研究机械设备故障诊断的有效载体。为有效进行故障诊断,需要对机械设备的故障信号进行提纯分析和特征提取等研究。提出基于时频分析技术的WVD和Hough变换结合的方法对低信噪比的故障信号进行提纯算法。首先分析了非平稳信号处理技术的基本原理,对原始信号的滤波和检测、频谱分析等处理,分析了时频分析特性和对应的条件,提出采用时间均值、频率均值、时间散布和频率散布四个特征值作为时频分析的特征提取量。仿真实验以某天然气压气站某型压缩机故障振动下采集信号样本为研究对象,进行提纯滤波和特征提取仿真,仿真实验得到降噪滤波和WVD及Hough变换算法下的检测结果,表明在强干扰背景SNR为-8dB下,有卓越的滤波降噪和检测性能,特征提纯检测性能相比传统算法提高18％以上。为天然气压缩机故障诊断奠定了可靠的理论基础。     

深海载人潜水器推进器系统故障诊断的新型主元分析算法

针对"蛟龙号"深海载人潜水器多推进器系统的故障检测与快速定位难题,将基于信度分配的模糊小脑神经网络(credit assignment-based fuzzy cerebellar model articulation controller, FCA–CMAC)应用于主元分析模型,提出一种基于主元分析(principal component analysis, PCA)的深海载人潜水器推进器系统故障诊断模型.首先,应用推进器系统正常运行的历史电流样本数据,由主元分析模型得到各推进器的电流预测值.其次,计算出故障检测统计量均方预测误差(squared prediction error, SPE),根据SPE值是否跳变,判断推进器系统有无故障发生.通过分别重构各推进器电流信号的SPE值对故障推进器进行定位和隔离.最后,通过对实际海试数据进行仿真处理说明了该算法的可行性,并通过与多层前馈神经网络(back propagation, BP)和常规小脑神经网络(cerebellar model articulation control-ler, CMAC)神经网络进行比较,说明基于FCA–CMAC神经网络的主元分析模型的优越性.     

An optimization decision support approach for risk analysis of carbon emission trading in electric power systems

Concerns over dramatic increasing electricity demand, exacerbating power shortage and changing climatic condition are emerging associated with municipal electric power systems (EPS). In this study, a risk-explicit mixed-integer full-infinite programming (RMFP) approach is developed for planning carbon emission trading (CET) in EPS. RMFP-CET has advantages in risk reflection and policy analysis, particularly when the input parameters are provided as crisp and functional intervals as well as probabilistic distributions. The developed method is applied to a real case study of CET planning of EPS in Beijing. Various electricity policies are incorporated within the modeling formulation for enhancing the RMFP-CET's capability. The results indicate that reasonable solutions have been generated, which are useful for making decisions of electricity production and supply as well as gaining insight into the tradeoffs among electricity supply risk, system cost, and CO₂ mitigation strategy.     

WTFM, software for well test analysis in fractured media combining fractional flow with double porosity and leakance approaches

The identification of the hydraulic characteristics and transport properties of fractured reservoirs requires the development of specific models that account for (i) the medium heterogeneity, e.g. the presence of major conductive fractures that delimit capacitive matrix blocks, with weakly open, dead end or isolated fractures, and (ii) for the geometrical arrangement of the major conductive fractures network, which dominates the flow at the scale of the well tests.Well Tests in Fractured Media (WTFM) software takes into account these two main features by combining radial flow generalized to fractional dimension, with the theory of double-porosity, including diffusivity in the second porosity, transient inter-porosity flow and inter-porosity skin effect, and with leakance. The implementation of this nD model, with n fractional, extends usefully the domain of application of the usual 1D/2D/3D double-porosity/leakance models for a large range of connection levels of fracture networks. Although the fractures geometry and properties are not considered one by one, or by directional families, they are taken into account by averaged properties and by the impact that the whole network has on the hydrodynamic behaviour. The accuracy of the coupled transient behaviours analysis is augmented by taking into account wellbore storage and skin effects. All together, the use of these different options allows matching a wide range of pumping test curves, characteristics of distinctive behaviours, with a limited number of parameters. Distinctive well test experiments, in both sedimentary and crystalline rocks, are presented for enlightening how the pertinent use of the model options improves predictions.