Fig 2 - uploaded by Pavel Taranenko
Content may be subject to copyright.
Scheme of equipment for fixing the meter: 1-basis; 2-pipe; 3-flowmeter; 4-fixed clamp; 5-movable clamp; 6-guide.
Source publication
Coriolis flow meters determine mass flow rate by measuring the phase shift of the signal pick-up coils. Therefore, changes in the phase shift amount not related to the flow of the measured medium cause mass flow measurement errors. The article is devoted to the experimental evaluation of the effect of mechanical boundary conditions of the Coriolis...
Similar publications
Conventional leak detection techniques require improvements to detect small leakage (<10%) in gas mixture pipelines under transient conditions. The current study is aimed to detect leakage in gas mixture pipelines under pseudo-random boundary conditions with a zero percent false alarm rate (FAR). Pressure and mass flow rate signals at the pipeline...
Citations
... What effect does changed pressure, temperature and solution had on the stability of the system was noticed by Post et al. (2012) with the help of a test. The findings were satisfactory, but sterility and portability [21][22][23] recommendations should be considered for clinical applications. Two different numerical approaches were applied to find an approximate solution. ...
In this research article a resonating tube was designed for Coriolis mass flow Sensor (CMFS) and sensor locations was varied. Resonant tube was designed to withstand maximum pressure with governing equations of coupled fluid structure problems. What is the result of sensor location on phase shift is the main goal of this research study. For omega type resonant tube from the base of vertical omega tube, the sensor locations have been varied from 60 mm to 120 mm in the present research article. CMFS is based on Coriolis Effect principle. For modelling of tube design, pro-E was used, and for analysis purpose Ansys 14.5 was used. Sensor locations and phase shift simulation results have been validated with experimental results. With the help of experimental results validation of sensor locations and phase shift simulations has been done. Omega type test configuration having L = 300 and D = 400 mm was used for experimentation for tube materials. The maximum values of phase shift was observed around 120 mm sensor location for 0.1 and 0.2 kg/s mass flow rate. It was observed from result that phase shift values are linearly varying with all range of mass flow rates. The resonant frequency is 24 Hz obtained from modal analysis for copper omega resonating tube.
... Hinged supports are included for their convenience (due to the simple linear mode shapes for a uniform pipe) in illustrating and interpreting analytical results, whereas clamped supports may be more realistic for applications. The equation of motion is solved for both types of boundary conditions, and other types of boundary conditions could be analyzed similarly ( [1,36] investigate effects of imperfect boundary conditions). ...
Flexural vibrations of a fluid-conveying pipe are investigated theoretically, with special consideration to the spatial shift in vibration phase caused by fluid flow and various imperfections. The latter includes small nonuniformity or asymmetry in stiffness, mass, or damping, and weak stiffness and damping nonlinearity. Besides contributing general understanding of wave propagation in elastic media with gyroscopic forces, this is relevant for the design, control, and troubleshooting of phase shift measuring devices like Coriolis mass flowmeters. A multiple time-scaling perturbation analysis is employed with a simple model of a fluid-conveying pipe with relevant imperfections, resulting in simple analytical expressions for the prediction of phase shift. For applications like Coriolis flowmetering, this allows for readily examining effects of a variety of relevant features, like small sensors and actuators, production inaccuracies, mounting conditions, wear, contamination, and corrosion. To second order of accuracy, only mass flow and asymmetrically distributed damping are predicted to introduce spatial phase shift, while nonuniformly distributed linear mass and stiffness, symmetrically distributed linear damping, and uniformly nonlinear stiffness and damping are all negligible in comparison. The analytical predictions are illustrated by examples and validated with excellent agreement against numerical analysis for realistic magnitudes of parameters.
... In earlier work [23], the authors studied the influence of the boundary conditions on the zero shift of a Coriolis flowmeter. However, these results were obtained for a flowmeter with empty tubes. ...
... There were no proposals for diagnosing the influence of the mechanical support on the Coriolis flowmeter measurements or recommendations for its installation. This paper complements the studies presented in [23]. ...
... Hinged supports are included for their convenience (due to the simple linear mode shapes for a uniform pipe) in illustrating and interpreting analytical results, whereas clamped supports may be more realistic for applications. The equation of motion is solved for both types of boundary conditions, and other types of boundary conditions could be analyzed similarly ( [1,36] investigate effects of imperfect boundary conditions). ...
Flexural vibrations of a fluid-conveying pipe is investigated, with special consideration to the spatial shift in phase caused by fluid flow and various imperfections, e.g., non-ideal supports, non-uniform stiffness or mass, non-proportional damping, weak nonlinearity, and flow pulsation. This is relevant for understanding wave propagation in elastic media in general, and for the design and trouble-shooting of phase-shift measuring devices such as Coriolis mass flowmeters in particular. A multiple time scaling perturbation analysis is employed for a simple model of a fluid-conveying pipe with imperfections. This leads to simple analytical expressions for the approximate prediction of phase shift, providing direct insight into which imperfections affect phase shift, and how. The analytical predictions are tested against results obtained by pure numerical analysis (Galerkin expansion), showing very good agreement.
In this research article a literature survey was performed for Coriolis mass flow Sensor (CMFS)
and research objective was identified. Resonant tube was designed to withstand maximum pressure with
governing equations of coupled fluid structure problems. CMFS is based on Coriolis Effect princip le. For
modelling of tube design, pro-E was used, and for analysis purpose Ansys 14.5 was used. Sensor locations and
phase shift simulation results have been validated with experimental results in final research work. With the
help of experimental results validation of sensor locations and phase shift simulations has been done. Omega
type test configuration having L = 300 and D = 400 mm was used for experimentation for tube materials. A
critical survey was done for evaluating exact research gaps and forming research objectives.
In Coriolis meter terminology, zero-shift is a general term describing the change in time-lag at zero-flow (zero-point) in response to any of a number of external factors. Zero-shift of a straight single-tube Coriolis meter has been investigated experimentally. The meter-tube was stainless-steel (2.66/2 × 300 mm) and has been tested across a range of flow rates (0–1 lpm, Red<104), pressures (1–4 barg) and pretensions (0 & 22 N). Zero-shift was shown to be principally dependent on the vibration-frequency. This was confirmed by operating the meter in both free and force-vibration modes. For zero-point to become a function of frequency the system must possess asymmetry, which may arise from the fluid or solid component. It was hypothesized that an asymmetric deformation field (i.e. a deviation from straightness) was the principal source of system asymmetry in this particular case. The deformation field was shown to be dynamic and therefore capable of modifying the zero-point even in fixed-frequency operation. The relationship between zero-point and frequency is complex owing to the many interconnected factors which can create asymmetry. However, it was shown that sensitivity of zero-point to frequency depends on the degree of asymmetry and particularly asymmetry of deformation-gradient (w0′).
To detect the phase difference of two vibration signals in a Coriolis flowmeter, the commonly used methods include the zero crossing phase detection method, the correlation function method and the Fourier transform method. However, these methods are subject to low accuracy, entire-cycle sampling and excessive calculation. To solve these problems, a Coriolis flowmeter experimental system was initially modeled, and then a phase difference detection method was built based on least squares and curve fitting. The results showed that this method could reduce the amount of calculation significantly without reducing the detection accuracy or adjusting the entire-cycle sampling. A simulation and a single-phase flow experiment indicated that this method was simple, practical and efficient, and it provided a new method for data processing with a Coriolis flowmeter.
