Figure 3 - uploaded by Luigi Serio
Content may be subject to copyright.
CMF010 (2 mm size, 60 g/s f.s.) Coriolis flowmeter: relative deviation of measured value with respect to calibration module and calculated pressure drop vs. mass flow
Source publication
Beginning in the 1980's, Coriolis meters have gained generalised acceptance in liquid applications with a worldwide installed base of over 300,000 units. To meet the demands of cryogenic applications below 20 K, off-the-shelf Coriolis meters have been used, with minor design modifications and operational changes. The meters were originally calibrat...
Context in source publication
Context 1
... performance (accuracy, reproducibility, pressure drop, zero stability) at nominal working conditions (supercritical helium at 5 K and 0.3 MPa) was first assessed in a test cryostat built and designed at CERN [1]. The following step was to test the flowmeter accuracy to metrological standard in a calibration module of absolute type, designed and built at IMGC (Ital y) [4], with accuracy of better than 0.5 % in liquid, superfluid and supercritical helium, between 1.7 K and 20 K. Figure 3 and 4 summarize the tests performed on two sizes of meters at various temperatures and helium fluid state (liquid, supercritical and superfluid). The final accuracy of the meters depends on the zeroing procedure in the lower range and in the accuracy of the measurement of the Young's modulus. ...
Similar publications
With the large number of superconducting radiofrequency (RF) cryomodules to be tested for the former LEP and the present LHC accelerator a RF test facility was erected early in the 1990’s in the largest cryogenic test facility at CERN located at Point 18. This facility consisted of four vertical test stands for single cavities and originally one an...
Citations
... Coriolis mass flowmeters (CMF) have been widely used for accurate mass flow measurement of a number of fluids [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Literature reviews of the development on CMF have been given in [15][16][17][18]. ...
... The Poisson's ratio also reduces at LNG temperature. At 120 K, thermal contraction of tube geometry term ( ( + ) 3 K. However, based on calibration of a U-tube CMF using LNG mass flow standard [22], the absolute deviations in mass flow measurement (from reference standard) are all below 0.49% for 1-4 kg/s range (without correction of the term kex ). ...
We have proposed new methods to reduce the LNG mass flow measurement uncertainty using Coriolis mass flowmeters (CMF). Since the uncertainty in the corrected Young’s modulus of meter tube is the dominating contribution factor, it is proposed to derive the Young’s modulus at LNG temperature using the calculated LNG density and the natural bending frequency measurement. The expanded uncertainty of the calculated Young’s modulus is evaluated to be 0.071%, which will enable the LNG mass flow measurement uncertainty of a straight-tube CMF to be reduced from 0.50% to 0.20% (k=2). This approach has the potential to provide more accurate LNG mass flow measurement in comparison to conventional methods which use the corrected Young’s modulus at LNG temperature. We have analysed the error in flow measurement using a U-tube CMF. An extra mass flow factor is shown to be the dominating mass flow measurement uncertainty factor due to high uncertainty in the measured Poisson’s ratio of the tube. A new method is proposed to calculate the Poisson’s ratio from torsional frequency and bending frequency measurements, with expanded uncertainty of 0.14%, 13 times lower than that of measured values. The LNG mass flow measurement uncertainty of a U-tube CMF is estimated to be to 0.24% (k=2) using the calculated Poisson’s ratio and Young’s modulus. Our theoretical analysis shows that accurate estimation of Young’s modulus and Poisson’s ratio can significantly reduce the LNG mass flow measurement uncertainty using CMF.
... CMFs have been used for cryogenic fluid mass flow measurement as reported in [87,[90][91][92][93][94][95][96][97][98]. The performance of CMF in mass flow measurement at cryogenic temperatures has been studied in [99] with consideration of the major changes of material properties. ...
... A CMF was customised for measuring liquid Helium (LHe) mass flowrate at 0.4 -29 g/s in [91]. The results showed a systematic error of +1.2% at 4.5 K when calibrated by a metrological LHe flow standard [91,108]. ...
... A CMF was customised for measuring liquid Helium (LHe) mass flowrate at 0.4 -29 g/s in [91]. The results showed a systematic error of +1.2% at 4.5 K when calibrated by a metrological LHe flow standard [91,108]. The expanded measurement uncertainty of the cryogenic LHe flow standard at 1.7 -20 K is 0.5% [91,108]. ...
The uncertainty of Coriolis mass flowmeter (CMF) has been investigated for liquefied natural gas (LNG) mass flowrate measurement. The expanded uncertainty of the Young's modulus of stainless steel 316 measured by NIST is evaluated to be 1.90%, taking into consideration the lot-to-lot variability of the material. We have shown that the corrected Young's modulus value at cryogenic temperature (120 K) has a smaller expanded uncertainty of 0.47%, through calibration of the CMF using traceable water calibration facility and a correction term to compensate the Young's modulus change from ambient to cryogenic temperature of 120 K. We have evaluated other mass flowrate measurement uncertainty factors including thermal expansion, pressure correction effect, temperature measurement, zero stability and meter repeatability. The expanded uncertainty of a CMF for LNG flowrate measurement is estimated to be 0.50% with the uncertainty coverage factor k=2. The dominating component is from the uncertainty of the corrected Young's modulus for stainless steel at cryogenic temperature. This uncertainty analysis shows that a CMF can provide very accurate mass flowrate measurement for LNG custody transfer.
... CMFs have been used for cryogenic fluid mass flow measurement as reported in [87,[90][91][92][93][94][95][96][97][98]. The performance of CMF in mass flow measurement at cryogenic temperatures has been studied in [99] with consideration of the major changes of material properties. ...
... A CMF was customised for measuring liquid Helium (LHe) mass flowrate at 0.4 -29 g/s in [91]. The results showed a systematic error of +1.2% at 4.5 K when calibrated by a metrological LHe flow standard [91,108]. ...
... A CMF was customised for measuring liquid Helium (LHe) mass flowrate at 0.4 -29 g/s in [91]. The results showed a systematic error of +1.2% at 4.5 K when calibrated by a metrological LHe flow standard [91,108]. The expanded measurement uncertainty of the cryogenic LHe flow standard at 1.7 -20 K is 0.5% [91,108]. ...
The uncertainty of Coriolis mass flowmeter (CMF) has been investigated for liquefied natural gas (LNG) mass flowrate measurement. The expanded uncertainty of the Young's modulus of stainless steel 316 measured by NIST is evaluated to be 1.90%, taking into consideration the lot-to-lot variability of the material. We have shown that the corrected Young's modulus value at cryogenic temperature (120 K) has a smaller expanded uncertainty of 0.47%, through calibration of the CMF using traceable water calibration facility and a correction term to compensate the Young's modulus change from ambient to cryogenic temperature of 120 K. We have evaluated other mass flowrate measurement uncertainty factors including thermal expansion, pressure correction effect, temperature measurement, zero stability and meter repeatability. The expanded uncertainty of a CMF for LNG flowrate measurement is estimated to be 0.50% with the uncertainty coverage factor k=2. The dominating component is from the uncertainty of the corrected Young's modulus for stainless steel at cryogenic temperature. This uncertainty analysis shows that a CMF can provide very accurate mass flowrate measurement for LNG custody transfer.
... It has been demonstrated, in particular, that the relationship of Young's modulus with respect to temperature is non-linear. In Ref. [46], the authors tested a Coriolis meter at cryogenic temperature (Fig. 12). As described above, a typical Coriolis meter needs to temperature measurements, for compensating the vibration characteristics of the sensing element. ...
... Electronic readout circuitry is less complex in the case of thermal, Coriolis and virtual flowmeters, where output is provided as a voltage and therefore a data acquisition card is needed. A capacitance-to-digital converter and a DSP are used in the case of the Fig. 12. Architecture of a Coriolis flow meter [46]. A collector (manifold) splits the flow into two parallel tubes, which are vibrated at a resonant frequency. ...
Mainstreams in research on measurement systems for cryogenic process monitoring are reviewed with the aim of defining key current trends and possible future evolutions. At this aim, research mainstreams are classified according to the measurand: liquid level, flow rate, and pressure. In these fields, research on innovative measurement systems is surveyed, by highlighting main basic ideas, original design solutions, main results, and positioning in the innovation landscape. Then, current and future research trends are outlined in order to draw evolution scenarios of measurement systems for cryogenics monitoring.
... However also in this case the flow meter cabling had to be improved, otherwise after a couple of years the flowmeter should be changed. Next efforts to qualify Coriolis flow meters for helium cryogenics were performed by Luigi Serio at CERN [4,13,20]. Very extensive measurements and comparison with other flow meters, e.g. Venturi, turbine, time-of-flight, showed superior behaviour of this sensor. ...
The measurement of coolant flow is important operational parameter for reliable operation of cryogenic system with superconducting magnets or cavities as well as for the system diagnostics in case of non-steady-state operation, e.g. during cool-down/warm-up or other transients. Proper flowmeter is chosen according to the different parameters, e.g. turn-down, operating temperature range, leak-tightness, pressure losses, long-term stability, etc. For helium cryogenics, the Venturi tube or Orifice, as well as Coriolis flow meters are often applied. For the present time, the orifices are usually used due to their simplicity and low costs, however, low turn-down range, large pressure drop, restriction of flow area, susceptibility to thermoacoustic oscillations limit their useful operation range. Operational characteristics of Venturi tubes is substantially improved in comparison to orifices, however, relative high costs and susceptibility to thermoacoustic oscillations still limit their application to special cases. The Coriolis flow meters do not have typical drawbacks of Venturi tube and orifices, however long-term stability over many years was not demonstrated yet. This paper describes the long-term behaviour of Coriolis flow meters after many years of operation at AMTF and XMTS facilities.
... In comparing the Venturi meter with the orifice meter, V-Cone [16] and the Coriolis mass flow meter [17], both the cost of installation and the cost of operation must be considered. (1): Using a device with higher nominal flow rate, the pressure drop could be reduced in compensation the turn down is reduced too and the required installation space enlarged (2): There is no information in the literature about the long term experience at low temperature conditions (3): Pressure transducer, differential pressure transducer and temperature measurement necessary (4): Stationary flow conditions without any capillary effect (5): Upstream length enlarged factor 2 compared to Venturi tubes (6): Upstream length reduced compared to Venturi tube – statement of manufacturer ...
The measurement of coolant flow rate is very important for the reliable
operation of superconducting magnets. The selection of the proper
instrument is governed by many variables including broad range of
temperature, high requirements on the leak tightness, low permanent
pressure losses, huge pressure overloads capability and insensitive
against magnetic fields. The Venturi tube satisfies these requirements,
and therefore, it is a favourite device for this application.
... Each circuit connected to the pressure transducer is provided with an additional small volume in order to prevent any thermo-acousticoscillation . The liquid helium mass flow is measured by means of both a cryogenic Coriolis [2] mass flow meter and a Venturi mass flow meter installed in series. The latter was installed since it was not known whether the vibrations introduced by the centrifugal pump could somehow interfere with the resonant oscillating system used in the Coriolis mass flow meter. ...
The toroid superconducting magnet of ATLAS-LHC experiment at CERN will be indirectly cooled by means of forced flow of liquid helium at about 4.5 K. A centrifugal pump will be used, providing a mass flow of 1.2 kg/s and a differential pressure of 40 kPa (ca. 400 mbar) at about 4300 rpm. Two pumps are foreseen, one for redundancy, in order to feed in parallel the cooling circuits of the Barrel and the two End-Caps toroid magnets. The paper describes the tests carried out at CERN to measure the characteristic curves, i.e. the head versus the mass flow at different rotational speeds, as well as the pump total efficiency. The pump is of the "fullemission" type, i.e. with curved blades and it is equipped with an exchangeable inducer. A dedicated pump test facility has been constructed at CERN, which includes a Coriolis-type liquid helium mass flow meter. This facility is connected to the helium refrigerator used for the tests at CERN of the racetrack magnets of the Barrel and of the End-Cap toroids.
The Toroidal Field (TF) system of ITER consists of 18 coils with design nominal current of 68 kA operating in steady state mode that provides 5.4 T in the plasma centre. The winding pack (WP) of each coil is formed by 7 stacked double pancakes which are connected between them in the coil lower region, sharing space with the current leads, supercritical Helium cooling piping and manifolds. The TF coils of ITER are not nuclear safety related, but the release of the 41 GJ of magnetic energy in a controlled way in case of a quench and the difficulties of replacing a failing TF coil make a reliable coil instrumentation design essential as investment protection.
The present paper describes not only the principles of the primary and secondary quench detection system of the ITER TF coils but also the operation monitoring instrumentation. The reliability of strain gauges, temperature sensors, pressure gauges and flow meters in the cryogenic environment and high electromagnetic noise environment is also discussed.
A new version of a system to monitor the average void fraction, φ, the quality, x, and the mass flow rate, G, of two-phase liquefied natural gas (LNG) flows is offered. It is based on a combination of a gamma-densitometer with a Cs-137 radioactive source and a narrowing device. The metrological characteristics of this system are estimated and its practical realization is substantiated. A model of ID = 100 mm has been manufactured and tested at the State Primary Special Standard of the Unit of Mass Flow Rate of Gas-Liquid Mixtures GET 195-2011 (Kazan, Russia) with simulated two-phase flows “Exxsol - compressed air”. The offered system can be used for pipelines up to ID = 500 mm by applying a gamma source with the necessary activity. The experiments on GET 195-2011 have shown that the void fraction error and the relative mass flow rate error for Exxsol do not exceed 5 % and 2 %, respectively, at φ < 50 %. It appears to be suitable for practical application. If one adds a second gamma-source (for example, Am-241) to the proposed system, it can serve as a separationless three-phase flow-meter for mixtures “oil-gas-formation water”.
This chapter provides an introduction to the engineering and design of cryostats. It reviews cryostat requirements and provides detailed technical information on topics relevant to cryostats. These topics include: materials, heat transfer and thermal insulation systems, structural supports, safety, instrumentation, seals and connections, transfer lines and thermoacoustic oscillations. The role of prototyping and series testing in cryostat development is also discussed. Numerous tables, figures and equations provide useful information for the cryostat designer.
