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Application of empirical mode decomposition based energy ratio to vortex flowmeter state diagnosis 被引量:4
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作者 孙志强 张宏建 《Journal of Central South University》 SCIE EI CAS 2009年第1期154-159,共6页
To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into i... To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into intrinsic mode functions using the empirical mode decomposition approach. Based on the empirical mode decomposition results, the energy of each intrinsic mode function was extracted, and the vortex energy ratio was proposed to analyze how the perturbation in the flow affected the measurement performance of the vortex flowmeter. The relationship between the vortex energy ratio of the signal and the flow condition was established. The results show that the vortex energy ratio is sensitive to the flow condition and ideal for the characterization of the vortex flowmeter signal. Moreover, the vortex energy ratio under normal flow condition is greater than 80%, which can be adopted as an indicator to diagnose the state of a vortex flowmeter. 展开更多
关键词 flow state diagnosis energy ratio vortex flowmeter empirical mode decomposition
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INVESTIGATION OF VORTEX SHEDDING INDUCED HYDRODYNAMIC VIBRATION IN VORTEX STREET FLOWMETER 被引量:2
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作者 Fu Xin,Xu Bing,Yang Huayong (State Key Laboratory of Fluid Power Transmission and Control,Zhejiang University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2001年第4期310-313,共4页
Vortex street flowmeter has been used in steady flow measurement for about three decades The benefits of this type of flowmeter include high accuracy,good linearty,wide measuring range,and excellent reliability Ho... Vortex street flowmeter has been used in steady flow measurement for about three decades The benefits of this type of flowmeter include high accuracy,good linearty,wide measuring range,and excellent reliability However,in unsteady flow measurement,the pressure disturbance as well as the noise from the system or surrounding can reduce the signal to noise ratio of the flowmeter seriously Aimed to use vortex street flowmeters in unsteady flow measurement,the characteristics of the vortex shedding induced hydrodynamic vibration around the prism bluff body in a vortex street flowmeter are investigated numerically and by expriments The results show that the hydrodynamic vibrations with 180° phase shift occur at the axisymmetric points of the channel around the bluff body The most intense vibration occurs at the points on the lateral faces close to the base of the prism The results provide therefore a useful reference for developing an anti interference vortex flowmeter using the different ial sensing technique. 展开更多
关键词 Vortex street flowmeter Vortex shedding induced hydrodynamic vibration Unsteady flow measurement Anti-interference performance
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Application of Hilbert-Huang transform to denoising in vortex flowmeter 被引量:4
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作者 孙志强 周孑民 周萍 《Journal of Central South University of Technology》 EI 2006年第5期501-505,共5页
Due to piping vibration, fluid pulsation and other environmental disturbances, variations of amplitude and frequency to the raw signals of vortex flowmeter are imposed. It is difficult to extract vortex frequencies wh... Due to piping vibration, fluid pulsation and other environmental disturbances, variations of amplitude and frequency to the raw signals of vortex flowmeter are imposed. It is difficult to extract vortex frequencies which indicate volumetric flowrate from noisy data, especially at low flowrates. Hilbert-Huang transform was adopted to estimate vortex frequency. The noisy raw signal was decomposed into different intrinsic modes by empirical mode decomposition, the time-frequency characteristics of each mode were analyzed, and the vortex frequency was obtained by calculating partial mode’s instantaneous frequency. Experimental results show that the proposed method can estimate the vortex frequency with less than 2% relative error; and in the low flowrate range studied, the denoising ability of Hilbert-Huang transform is markedly better than Fourier based algorithms. These findings reveal that this method is accurate for vortex signal processing and at the same time has strong anti-disturbance ability. 展开更多
关键词 flow measurement vortex flowmeter DENOISING Hilbert-Huang transform signal processing
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Study on hydrodynamic vibration in fluidic flowmeter 被引量:2
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作者 WANG Chi-yu ZOU Jun +1 位作者 FU Xin YANG Hua-yong 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第9期1422-1428,共7页
The characteristics of the fluidic flowmeter,which is a combination of impinged concave wall and bistable fluid amplifier,is investigated by experimental studies and numerical simulations. The numerical approaches are... The characteristics of the fluidic flowmeter,which is a combination of impinged concave wall and bistable fluid amplifier,is investigated by experimental studies and numerical simulations. The numerical approaches are utilized to examine the time dependent flow field and pressure field inside the proposed flowmeter. The effect of varying structural parameters on flow characteristics of the proposed fluidic flowmeter is investigated by computational simulations for the optimization. Both the simulation and experimental results disclose that the hydrodynamic vibration,with the same intensity,frequency and 180° phase shift,occurs at axisymmetric points in the feedback channel of the fluidic flowmeter. Using the structural combination of impinged concave wall and bistable fluid amplifier and differential signal processing technique,a novel fluidic flowmeter with excellent immunity and improved sensibility is developed. 展开更多
关键词 flowmeter Fluidic Hydrodynamic vibration Coanda effect
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Influence of bluff body shape on wall pressure distribution in vortex flowmeter 被引量:3
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作者 孙志强 李志勇 +1 位作者 蒋赟 周宏亮 《Journal of Central South University》 SCIE EI CAS 2013年第3期724-729,共6页
To investigate the influence of bluff body shape on wall pressure distribution in a vortex flowmeter,experiments were conducted on a specially designed test section in a closed water rig at Reynolds numbers of 6.2... To investigate the influence of bluff body shape on wall pressure distribution in a vortex flowmeter,experiments were conducted on a specially designed test section in a closed water rig at Reynolds numbers of 6.2×10 4-9.3×10 4.The cross sections of the bluff bodies were semicircular,square,and triangular shaped,and there were totally 21 pressure tappings along the conduit to acquire the wall pressures.It is found that the variation trends of wall pressures are basically identical regardless of the bluff body shapes.The wall pressures begin to diverge from 0.3D(D is the inner diameter of the vortex flowmeter) in front of the bluff body due to the diversity in shape,and all reach the minimum values at 0.3D behind the bluff body.A discrepancy between the triangular or square cylinder and the semicircular cylinder in wall pressure change is observed at 0-0.1D behind the bluff body.It is also found that the wall pressures and irrecoverable pressure loss coefficients increase with flow rates,and the triangular cylinder causes the smallest irrecoverable pressure loss at a fixed flow rate. 展开更多
关键词 vortex flowmeter bluffbody shape wall pressure irrecoverable pressure loss
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Research on double differential pressure dynamic flowmeter 被引量:1
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作者 Liu Tao Zuo Zhibing Yin Zhigang 《High Technology Letters》 EI CAS 2019年第4期378-385,共8页
When testing an electrohydraulic proportional valve,it is necessary to test the high frequency dynamic flow with bias.Because of the limitation of the piston stroke,a no-load hydraulic cylinder is only suitable for a ... When testing an electrohydraulic proportional valve,it is necessary to test the high frequency dynamic flow with bias.Because of the limitation of the piston stroke,a no-load hydraulic cylinder is only suitable for a reciprocating symmetrical dynamic flow test.Since the traditional differential pressure flowmeter is affected by viscosity and inertia of the fluid,it is only suitable for measuring steady flow.Therefore,a new type of double pressure differential dynamic flowmeter is designed to improve the traditional differential pressure flowmeter.The influence of fluid viscosity and inertia in the flow process are negated by subtracting the differential pressure in section expansion from the differential pressure in section contraction.The double differential pressure flowmeter is modeled and a flow meter prototype is designed.Then,the flow coefficients are identified and corrected by a practical test.Finally,the dynamic performance and steady-state precision of the flowmeter are verified by comparing with the test results of the no-load hydraulic cylinder.The double differential pressure dynamic flowmeter is proven to measure dynamic flow accurately,especially at higher dynamic frequencies. 展开更多
关键词 dynamic flowmeter double differential pressure contrast experiment coefficient correction
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Numerical Solution of the Weight Function for Electromagnetic Flowmeter 被引量:3
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作者 FAN Shi-wei CAO Zhang +1 位作者 XU Li-jun WANG Gang 《Computer Aided Drafting,Design and Manufacturing》 2010年第2期36-41,共6页
A numerical solution of the weight function for a two-electrode electromagnetic flowmeter was proposed. The solution was obtained by using the finite element method based on the basic equation of a traditional two-ele... A numerical solution of the weight function for a two-electrode electromagnetic flowmeter was proposed. The solution was obtained by using the finite element method based on the basic equation of a traditional two-electrode electromagnetic flowmeter. The two-dimensional distribution of the weight function of the electromagnetic flowmeter obtained was verified by the analytical solution. Three-dimensional distribution of the weight function was also presented in the paper. It can be employed to analyze the sensitivity and linearity of the electromagnetic flowmeter with non-uniform magnetic field, and even to assist the design of the excitation coil pair. 展开更多
关键词 electromagnetic flowmeter weight function finite element method numerical solution virtual current
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Research and Development on β Ray Ionization Gas Flowmeter
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作者 安伟 魏任之 +2 位作者 张启明 朱煜 叶平 《International Journal of Mining Science and Technology》 SCIE EI 1999年第2期179-182,共4页
A new method of measuring gas flow in heavy or medium pipe based on the ionization effect of gas irradi ated with rays is presented. The mesurement principle of the flowmeter has been theoretically analyzed,the struct... A new method of measuring gas flow in heavy or medium pipe based on the ionization effect of gas irradi ated with rays is presented. The mesurement principle of the flowmeter has been theoretically analyzed,the structure form and the base of relevant parameter’s choice of the flowmeter have been given, and theintellectual instrument is developed. The results of experiment show that the per formance of the flowmeter is stable, the precision can reach 1 to 1. 5 percent, and it has fairly capability to resist disturbance and pollution. 展开更多
关键词 flowmeter IONIZATION GAS ISOTOPE instrument
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Ultrahigh performance of Ti-based glassy alloy tube sensor for Coriolis mass flowmeter 被引量:2
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作者 马朝利 A.INOUE 张涛 《中国有色金属学会会刊:英文版》 CSCD 2006年第A02期202-205,共4页
关键词 钛基玻璃合金管 科里奥利质量流量计 传感器 超高性能
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DESIGN,FABRICATION,TESTING AND MECHANICAL ANALYSIS OF BULK-MICROMACHINED FLOWMETERS
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作者 王小保 钱劲 张大成 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2004年第2期152-158,共7页
Micromachined piezoresistive flowmeters with four different types of sensing struc- tures have been designed,fabricated and tested.Piezoresistors were defined at the end of the sensors through p-diffusion,and their va... Micromachined piezoresistive flowmeters with four different types of sensing struc- tures have been designed,fabricated and tested.Piezoresistors were defined at the end of the sensors through p-diffusion,and their values were about 3.5kΩ.Wheatstone bridge was configured with the piezoresistors in order to measure the output response.The output voltage increases with increasing flow rate of air,obeying determined relationships.The testing results show that the sensors that are designed for measuring 10L/M in full operational range have desired sensitivities.The sensor chip is manufactured with bulk-micromachining technologies,requiring a set of seven masks. 展开更多
关键词 micromachined flowmeters bulk-micromachining PIEZORESISTIVITY Wheatstone bridge
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Development of DSP-Based Dynamic Signal Processing Module for Turbine Flowmeter
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作者 Liu Yuan Zhang Tianhong 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2016年第5期546-551,共6页
Traditional signal processing methods for turbine flowmeter are unable to solve the contradiction between the real-time performance and the accuracy during the aeroengine bench test or hardware in the loop(HIL)simulat... Traditional signal processing methods for turbine flowmeter are unable to solve the contradiction between the real-time performance and the accuracy during the aeroengine bench test or hardware in the loop(HIL)simulation of aeroengine control system.A dynamic flow measurement method based on cycle number of the flowmeter is proposed.And a DSP-based multi-functional dynamic signal processing module for turbine flowmeter is built to validate the method.The developed system can provide three types of output modes including PWM,frequency and D/A.At the same time,the results can be displayed instantly with the module of serial communication interface to obtain dynamic flow signal with good precision.Experimental results show that the stability of flow measurement is greatly improved with precision guaranteed and the real-time response reaches the maximum limit of turbine flowmeter. 展开更多
关键词 turbine flowmeter DSP cycle-number filter dynamic flow measurement
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Accuracy of Medical Oxygen Flowmeters: A Multicentric Field Study
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作者 Frédéric Duprez Maria Barile +4 位作者 Thierry Bonus Grégory Cuvelier Sandra Ollieuz Shahram Mashayekhi Alexandre Legrand 《Health》 2014年第15期1978-1983,共6页
The accuracy of 476 oxygen flowmeters was investigated using a thermal mass flowmeter in eight hospitals in France and Belgium. Different oxygen flow rates (2 to 15 l/min) were evaluated at the patient’s bed. When th... The accuracy of 476 oxygen flowmeters was investigated using a thermal mass flowmeter in eight hospitals in France and Belgium. Different oxygen flow rates (2 to 15 l/min) were evaluated at the patient’s bed. When the sample was considered as a whole, the accuracy of delivered flow was acceptable but precision was poor. The variability of the delivered flow between devices was greater when a low flow rate was required. Compensated-pressure oxygen flowmeters for these low rates were more accurate than their non-compensated counterparts. This study emphasizes the need to individually adapt the oxygen flow rate each time a patient has to move from one flowmeter to another. 展开更多
关键词 MEDICAL Device ACCURACY OXYGEN Therapy flowmeter
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Study on Hydrodynamic Vibration in Dual Bluff Body Vortex Flowmeter
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作者 傅新 杨华勇 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2001年第2期123-128,共6页
The characteristics of the dual bluff body vortex shedding is investigated, and the possibility to use dual bluff body combinations to strengthen the hydrodynamic vibration around the bluff body objects is explored. T... The characteristics of the dual bluff body vortex shedding is investigated, and the possibility to use dual bluff body combinations to strengthen the hydrodynamic vibration around the bluff body objects is explored. The numerical and experimental approaches were utilized to examine the time dependent flow field and the pressure oscillation around the bluff bodies. The numerical data were obtained by the advanced large eddy simulation model. The experiment was conducted on a laboratory scale of Karman vortex flowmeter with 40 mm diameter. It is revealed that the optimized dual bluff body combinations strengthened the hydrodynamic vibration. It was also found that the hydrodynamic vibration with 180° phase difference occurred at the axisymmetric points of circular pipe on the lateral faces of the equilateral triangle-section bluff bodies. Using the dual bluff body configuration and the differential sensing technique, a novel prototype of vortex flowmeter with excellent noise immunity and improved sensibility was developed. 展开更多
关键词 flowmeter vortex shedding dual bluff body hydrodynamic vibration
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超临界二氧化碳流量测量方法研究
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作者 罗凡 蒋岳峰 +3 位作者 甘蓉 雷励 赵宇轩 钟忠 《中国测试》 CAS 北大核心 2024年第1期62-68,共7页
在临界点附近的超临界流体,操作温度或操作压力的微小变化,都会引起超临界流体密度的很大变化,因此,尚无能够满足实时、准确、可溯源要求的超临界流体流量测量方法及仪表。该文首先分析超临界二氧化碳在拟临界温度区域的物理特性;然后... 在临界点附近的超临界流体,操作温度或操作压力的微小变化,都会引起超临界流体密度的很大变化,因此,尚无能够满足实时、准确、可溯源要求的超临界流体流量测量方法及仪表。该文首先分析超临界二氧化碳在拟临界温度区域的物理特性;然后分别研究科里奥利质量流量计和差压流量计的超临界流体测量特点,确定流量测量所需的工况条件;最后提出一种以科里奥利质量流量计对差压流量计进行动态密度修正,从而提高超临界流体质量流量测量精度的流量计组合方法。验证实验中,该文以质量法液体流量标准装置对上述两种流量计进行校准,再基于雷诺数近似原理采用质量法气体流量标准装置进行模拟测试,评估动态响应能力及两种被测介质之间的测量误差。实验结果表明:该流量计组合方法具备超临界二氧化碳流量测量的能力,可实现以科里奥利质量流量计作为工作级标准的超临界二氧化碳量值溯源。 展开更多
关键词 超临界二氧化碳 科里奥利质量流量计 差压式流量计
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基于间接核查法的流量计云在线运行核查方法 被引量:1
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作者 方修睦 杨大易 《暖通空调》 2024年第1期75-80,共6页
在供热物理设备网中,除不同规模的流量计群外,还设有大量与流量有关的设备及部件。本文研究了利用供热系统的机理、被核查流量计的相关参数、供热物理设备网中设置的具有流量特性的设备或部件来判断被核查流量计工作状态的方法,并在此... 在供热物理设备网中,除不同规模的流量计群外,还设有大量与流量有关的设备及部件。本文研究了利用供热系统的机理、被核查流量计的相关参数、供热物理设备网中设置的具有流量特性的设备或部件来判断被核查流量计工作状态的方法,并在此基础上提出了流量计的云在线运行核查技术流程,以快速判断在线应用的流量计的技术性能是否满足使用要求,解决供热企业核查人员及核查仪器设备不足的缺陷,有效提升智慧供热系统数据质量和提高控制系统的安全。 展开更多
关键词 智慧供热 流量计 间接核查法 云在线运行核查 数据质量
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基于光栅尺测量的明渠流量计校准装置及其在线校准方法研究
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作者 吴忠杰 吴丽滨 +1 位作者 易国贤 周军红 《中国测试》 CAS 北大核心 2024年第S01期134-138,共5页
明渠流量计是监测水流量的一种计量器具,广泛应用于各行各业。因其不便拆卸、堰槽设计不规范、校准方法缺失等原因,使得明渠流量计在线溯源成为业内亟需解决的难题。该文开发出一款基于光栅尺测量的明渠流量计校准装置,并应用该装置研... 明渠流量计是监测水流量的一种计量器具,广泛应用于各行各业。因其不便拆卸、堰槽设计不规范、校准方法缺失等原因,使得明渠流量计在线溯源成为业内亟需解决的难题。该文开发出一款基于光栅尺测量的明渠流量计校准装置,并应用该装置研究出模拟液位法的明渠流量计在线校准方法。该方法克服了标准液位计法及流速面积法等现有溯源方法存在的不足,具有操作简便、测量准确、模拟水位可调、过程智能化等特点,为明渠流量计在线溯源提供技术支撑。 展开更多
关键词 计量学 明渠流量计 光栅尺 校准装置 在线校准
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基于CFD的传感器体积对旋进旋涡流量计的影响
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作者 沈春根 金昆 +2 位作者 朱云明 胡尊豪 郭二廓 《排灌机械工程学报》 CSCD 北大核心 2024年第9期895-899,共5页
针对旋进旋涡流量计的精确测量,使用CFD数值模拟软件,以DN20口径的旋进旋涡流量计作为研究对象,得到了类似于钝体涡街旋涡脱落的现象,并对仿真的可行性进行了深入分析,验证了仿真工作的可靠性.分析比较低流量下不同取压点的压差,得到内... 针对旋进旋涡流量计的精确测量,使用CFD数值模拟软件,以DN20口径的旋进旋涡流量计作为研究对象,得到了类似于钝体涡街旋涡脱落的现象,并对仿真的可行性进行了深入分析,验证了仿真工作的可靠性.分析比较低流量下不同取压点的压差,得到内流场压差变化规律,确定了DN20流体域的最佳取压点.将压电传感器置于最佳取压点后,使用音速喷嘴装置进行试验.将试验数据与仿真数据进行对比,发现两者之间存在一定的误差.分析其中原因,以小口径壳体内压电传感器自身体积较大为切入点,去除流体域内压电传感器体积,将去除压电传感器体积前后的流体域进行仿真,对结果比较分析,发现去除压电传感器体积后的流体域仿真得到的K值系数与试验值误差较小,说明压电传感器体积对内流场有一定影响,并且压电传感器的探针放置于流量计中会一定程度地增加旋进旋涡流量计的压力损失. 展开更多
关键词 旋进旋涡流量计 数值模拟 压电传感器 压力损失 取压点
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基于能量守恒定律对涡轮流量计的脉动误差上限的估算
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作者 刘可薇 胡银春 张禾 《电子测量与仪器学报》 CSCD 北大核心 2024年第2期85-91,共7页
在管道输运当中,非稳态流会使涡轮流量计的计量结果产生偏差。为了指导脉动流工况下的涡轮流量计选型和修正,需估算脉动工况对涡轮流量计产生的最大脉动误差。忽略流体压力和温度变化影响,基于涡轮流量计的动态特性和能量守恒定律,在一... 在管道输运当中,非稳态流会使涡轮流量计的计量结果产生偏差。为了指导脉动流工况下的涡轮流量计选型和修正,需估算脉动工况对涡轮流量计产生的最大脉动误差。忽略流体压力和温度变化影响,基于涡轮流量计的动态特性和能量守恒定律,在一个脉动周期内计算脉动流和定常流对叶轮的做功比值,推导得出正弦脉动流误差上限公式。基于6DOF模型和UDF建立了涡轮流量计CFD仿真模型,搭建了空气流实验平台,以工作级流量标准装置作为标准表,被校表和标准表间采用内置整流器的管段相连。对比定常流下的流量值,计算各脉动工况下的误差限值。综合各脉动工况点,上限公式与CFD仿真所得脉动误差上限的最大差值为0.281%,与空气流实验所得脉动误差上限的最大差值为0.224%。经CFD仿真和空气流实验结果对比验证,脉动误差上限公式较为准确,可以直接用于脉动频率大于10 Hz的工况下误差值的估计和修正。 展开更多
关键词 涡轮流量计 数学模型 CFD 正弦波脉动流 实流实验
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基于峰值比拟合匹配的时差式气体超声波流量计
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作者 李斌 李鹏飞 陈洁 《自动化与仪表》 2024年第7期115-118,122,共5页
时差式气体超声波流量计的回波信号在气体中传播时能量衰减严重,且存在着不同程度的幅值晃动问题。因此如何在幅值晃动的气体回波信号中确定特征点,以准确测量回波信号渡越时间及其顺、逆流渡越时间差,是当前时差式气体超声波流量计信... 时差式气体超声波流量计的回波信号在气体中传播时能量衰减严重,且存在着不同程度的幅值晃动问题。因此如何在幅值晃动的气体回波信号中确定特征点,以准确测量回波信号渡越时间及其顺、逆流渡越时间差,是当前时差式气体超声波流量计信号处理方法的主要研究热点。该文基于超声回波信号的数学模型,研究构建了一种基于峰值比拟合匹配的信号处理方法,利用拟合指标来筛选符合匹配条件的波形。并且通过实际数据验证了该方法的有效性和优越性。 展开更多
关键词 时差式气体超声波流量计 峰值比 特征点提取
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基于归一化原理的流量计群在线核查方法
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作者 方修睦 杨大易 《暖通空调》 2024年第1期81-88,9,共9页
目前供热系统中的流量计带病工作较多、流量测量数据可信度低、判断流量计工作情况难。本文研究了利用归一化方法解决流量计群的测量数据不闭合问题,给出了流量及热量的修正方法;分析了总流量变化时各热力站的流量比变化率,以及正常运... 目前供热系统中的流量计带病工作较多、流量测量数据可信度低、判断流量计工作情况难。本文研究了利用归一化方法解决流量计群的测量数据不闭合问题,给出了流量及热量的修正方法;分析了总流量变化时各热力站的流量比变化率,以及正常运行的流量计的流量比变化率的区间,证明了利用流量比变化率可实现流量计的云在线核查,为保障智慧供热系统中的数据正确及完整提供了简单、实用的方法。 展开更多
关键词 流量计 在线运行核查 归一化方法 智慧供热 流量比变化率
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