540 research outputs found
Complex Signal Processing for Coriolis Mass Flow Metering in Two-Phase Flow
This paper presents a new signal processing method based on Complex Bandpass
Filtering (CBF) applied to the Coriolis Mass Flowmeter (CMF). CBF can be
utilized to suppress the negative frequency component of each sensor signal to
produce the corresponding analytic form with reduced tracking delay. Further
processing of the analytic form yields the amplitude, frequency, phase and
phase difference of the sensor signals. In comparison with previously published
methods, CBF offers short delay, high noise suppression, high accuracy and low
computational cost. A reduced delay is useful in CMF signal processing
especially for maintaining flowtube oscillation in two/multi-phase flow
conditions. The central frequency and the frequency range of the CBF method are
selectable so that they can be customized for different flowtube designs
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Coriolis flowmeters: A review of developments over the past 20 years, and an assessment of the state of the art and likely future directions
This paper starts from a brief revisit of key early published work so that an overview of modern Coriolis flowmeters can be provided based on a historical background. The paper, then, focuses on providing an updated review of Coriolis flow measurement technology over the past 20 years. Published research work and industrial Coriolis flowmeter design are both reviewed in details. It is the intention of this paper to provide a comprehensive review study of all important topics in the subject, which include interesting theoretical and experimental studies and innovative industrial developments and applications. The advances in fundamental understanding and technology development are clearly identified. Future directions in various areas together with some open questions are also outlined.This is the accepted manuscript version. The final version is available from Elsevier at http://dx.doi.org/10.1016/j.flowmeasinst.2014.08.01
Multiphase flow measurement using gamma-based techniques
The oil and gas industry need for high performing and low cost multiphase meters is ever more justified given the rapid depletion of conventional oil reserves. This has led oil companies to develop smaller/marginal fields and reservoirs in remote locations and deep offshore, thereby placing great demands for compact and more cost effective soluti8ons of on-line continuous multiphase flow measurement. The pattern recognition approach for clamp-on multiphase measurement employed in this research study provides one means for meeting this need. Cont/d
Experimental investigations of two-phase flow measurement using ultrasonic sensors
This thesis presents the investigations conducted in the use of ultrasonic
technology to measure two-phase flow in both horizontal and vertical pipe flows
which is important for the petroleum industry. However, there are still key
challenges to measure parameters of the multiphase flow accurately. Four
methods of ultrasonic technologies were explored.
The Hilbert-Huang transform (HHT) was first applied to the ultrasound signals of
air-water flow on horizontal flow for measurement of the parameters of the two-
phase slug flow. The use of the HHT technique is sensitive enough to detect the
hydrodynamics of the slug flow. The results of the experiments are compared
with correlations in the literature and are in good agreement.
Next, experimental data of air-water two-phase flow under slug, elongated
bubble, stratified-wavy and stratified flow regimes were used to develop an
objective flow regime classification of two-phase flow using the ultrasonic
Doppler sensor and artificial neural network (ANN). The classifications using the
power spectral density (PSD) and discrete wavelet transform (DWT) features
have accuracies of 87% and 95.6% respectively. This is considerably more
promising as it uses non-invasive and non-radioactive sensors.
Moreover, ultrasonic pulse wave transducers with centre frequencies of 1MHz
and 7.5MHz were used to measure two-phase flow both in horizontal and
vertical flow pipes. The liquid level measurement was compared with the
conductivity probes technique and agreed qualitatively. However, in the vertical
with a gas volume fraction (GVF) higher than 20%, the ultrasound signals were
attenuated.
Furthermore, gas-liquid and oil-water two-phase flow rates in a vertical upward
flow were measured using a combination of an ultrasound Doppler sensor and
gamma densitometer. The results showed that the flow gas and liquid flow rates
measured are within ±10% for low void fraction tests, water-cut measurements
are within ±10%, densities within ±5%, and void fractions within ±10%. These
findings are good results for a relatively fast flowing multiphase flow
Flow Measurement Challenges for Carbon Capture, Utilisation and Storage
Carbon Capture, Utilisation and Storage (CCUS) is a key element in the United Kingdom Government strategy for reducing carbon dioxide (CO2) emissions. The UK aims to capture and store 10 million tonnes of CO2 each year by 2030.
At each stage in the CCUS infrastructure, accurate measurement of the CO2 flow rate is required, over a range of temperatures, pressures, flow rates and fluid phases, where the flow measurement must be validated through a credible traceability chain. The traceability chain provides the underpinning confidence required to verify meter performance, financial and fiscal transactions, and environmental compliance. The UK equivalent of the EU Emissions Trading System (EU ETS) specifies a maximum uncertainty value for CO2 flow measurement. Accordingly, the provision of accurate and traceable flow measurement of CO2 is a prerequisite for an operational CCUS scheme.
However, there are currently no CO2 flow measurement facilities, nationally or internationally, providing traceable flow calibrations of gas phase, liquid/dense phase and supercritical phase CO2 that replicate real-world CCUS conditions. This lack of traceable CO2 gas and liquid flow measurement facilities and associated flow measurement standards is a significant barrier to the successful implementation of CCUS projects worldwide.
This paper presents an overview of the traceability chain required for CO2 flow measurement in the UK and globally. Current challenges are described along with potential solutions and opportunities for the flow measurement community
Industrial flow measurement
This thesis discusses the intrinsic worth of a published work, âIndustrial Flow
Measurementâ (Appendix A), a handbook written and revised by the author over a
period of 30 years. The author first discusses the need to measure flow and then
moves on to the raison dâĂȘtre of the handbook before looking at a brief history of flow
measurement. Although not claiming that any single attribute of the handbook is
unique, the author nonetheless postulates that because it incorporates several
distinctive features, at a number of different levels, these agents combine to make it
one-of-a- kind.
The author moves on to an overview of existing flow metering technologies discussed
within the handbook. Finally, he looks at what he considers is a major gap in the
collected body of knowledge â the field of multiphase and water-cut metering and
provides a justification, not only for its inclusion in the future but for future
investigation
Development of a centrifugal microfluidic device for separation and sorting in biological fluids
A wide interest in employing micron-scale, integrated biochemical analysis systems for economical and rapid diagnosis has been the principal motivation behind this project. Low operating costs, portability and fast diagnosis times make centrifugal microfluidic devices an attractive option in patient-side diagnostics. Some essential tasks to be performed in microfluidic devices are sample-reagent transport, mixing, separation and detection. All these tasks require precise control of the RPM and spinning time. Centrifugal micro-fluidic platforms have been successfully implemented for detection of hepatitis A, tetanus, as well as for measurement of haemoglobin and hematocrit, for DNA analysis, and for assessment of cardiac disease etc. by assaying biological fluids like blood, saliva, and urine.
This thesis presents the construction, including the micro-machining and testing of a multi-channel centrifugal microfluidic device for point-of-care (POC) diagnostics. A low cost device capable of delivering controlled revolutions per minute was made by modifying a CD-ROM drive and a polymer disk was used to handle the fluids. A network of microfluidic channels and reservoirs was fabricated on the CD by using a rapid prototyping method. The reservoirs hold the biofluid sample, meter the volume of fluid accurately and also serve as a component of capillary burst valves to gate the flow of fluid. Micromachining techniques like photolithography, wet-etching have been discussed for mass production of the prototype used for this research.
Theoretical analysis of the burst frequency for passive capillary valves is reported and compared with practical results. The goal of this thesis was to develop a low cost device and demonstrate its use in the separation, and metering of plasma from blood using centrifugal microfluidics. One challenge when using blood for diagnosis is to separate the blood plasma from the rest of the blood cells. Concepts of blood centrifugation and particle displacement on a spinning disk have been employed to calculate the required RPM. Experiments were carried out on various geometries in order to achieve the maximum level of separation. The results of these experiments have been reported. It has been established that centrifugal microfluidics can be used to accurately control the flow of fluids in microchannels and this can be used for reliable low cost point-of-care diagnostics
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