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Page 6 of 912 Results 51 - 60 of 9113

M. MacDonald, N. Glen, M. A. de Huu, R. Maury, S. Rønneberg, A. Wiener
Measurement uncertainty tool for HRS dispensers

Verifications of hydrogen refuelling stations have shown that variations in the station design and operation can greatly influence accuracy at the dispenser, and there are sources of error unrelated to the flow meter which if uncorrected make it difficult to achieve the accuracy requirements of OIML R-139. To improve dissemination of knowledge in this area, an interactive measurement uncertainty tool has been developed which allows the user to specify a range of different station configurations and filling scenarios to estimate the resulting errors at the dispenser. This is intended to serve as a basis for HRS manufacturers to improve HRS designs with respect to billing accuracy and to assist notified bodies in understanding uncertainty contributions from an HRS and the corrections required. This paper describes the initial version of the HRS uncertainty tool, explaining the inputs required from the user, the sources of measurement uncertainty considered, how the flow meter behaviour is modelled, and which calculations are implemented.

Dr. C. Mills, Dr. G. Chinello
Flow Measurement in Support of Carbon Capture, Utilisation and Storage

Carbon Capture, Utilisation and Storage (CCUS) is a key United Kingdom Government strategy for reducing carbon dioxide (CO2) emissions to combat the potentially catastrophic effects of climate change. The UK aims to capture and store 10 million tonnes of CO2 each year by 2030. Across the entire CCUS value chain, each of the stages require accurate measurement of CO2 at temperatures, pressures, flow rates and fluid phases that must be validated through a credible traceability chain for flow. This traceability chain would provide the underpinning confidence in meter performance, financial and fiscal transactions and, critically, environmental compliance. The UK-adopted version of the EU Emissions Trading System (EU ETS) has specified an uncertainty value for CO2 flow measurement that must be adhered to. Accordingly, the provision of accurate and traceable flow measurement of CO2 in the UK and internationally will be essential for the successful operation of CCUS Unfortunately, there are currently no CO2 flow measurement facilities in the world that are capable of traceable flow calibrations of gas phase, liquid/dense phase and supercritical phase CO2 that replicate real-world CCUS conditions. The absence of traceable CO2 gas and liquid flow measurement facilities and accompanying national or international flow measurement standards could seriously impede the widespread deployment of CCUS. These significant barriers could potentially jeopardise the successful implementation of CCUS projects worldwide, not least because these will be governed by legislation and environmental regulations requiring traceable measurement.This paper presents an overview of the current traceability chain for CO2 flow measurement in the UK and globally. Current challenges will be detailed along with potential solutions and opportunities for the measurement community.

R. Maury, M.A. De Huu, M. MacDonald, P. T. Neuvonen, A. Wiener
Secondary standard for hydrogen refuelling station verification: Method and requirements

The requirements for the refuelling process to minimise overheating and overfilling have a considerable influence on HRS design and have a substantial impact on prospective fuelling performance. Type approval of HRS is a complex, expensive and time-consuming process whereas on-field inspection should be quick, cost efficient, reliable, and easy to perform. This paper describes a secondary flow standard which could be used to meet those objectives. Through the implementation of secondary standard verification, type approval time willdrastically decrease from 2 days of testing (using the primary standard) to half a day. Thus, decreasing operation time and cost which will appeal to investors (OPEX reduction). This will pave the way for the development of new hydrogen infrastructure to facilitate the increase in hydrogen cars.

Yongsheng Zhang, Yanjun Liu
Development of Dynamic Response Characteristics Calibration Device for Liquid Flowmeter

In order to study the dynamic response characteristics of liquid flowmeter, a dynamic flow device based on superposition principle is established. The device generates the main flow through the screw pump; The positive step or negative step flow component is generated by opening or closing the high-speed solenoid valve; and the Sinusoidal pulsating flow component is formed by the sinusoidal mechanism. The real step flow or pulsating flow can be formed by superimposing the step flow component or pulsating flow component on the main flow. The system is equipped with a weighing system to measure the average flow. The test shows that the step flow component can change from 4 L/min to 20 L/min, and the uncertainty of step amplitude is 5 % (k = 2); The frequency of pulsating flow can change from 5 Hz to 50 Hz, the amplitude can change from 5 L/min to 20 L/min, and the uncertainty of instantaneous flow is 0.5 % (k = 2). The device can be used to calibrate and evaluate the time constant, frequency response characteristics and mean flow error of flowmeter, and is expected to improve the accuracy of unsteady flow measurement.

M. A. de Huu, R. Maury, M. MacDonald, S. Rønneberg, A. Wiener
Key comparison of gravimetric standards for hydrogen refuelling stations

There are currently several mobile gravimetric standards for testing and calibrating hydrogen refuelling stations in operation. These standards are compliant for fuel delivery to light-duty vehicles according to the SAE J2601 protocol and provide measurement uncertainties that are low enough to use them for type-approval testing according to OMIL R139 recommendation. An international field comparison under real conditions is requiredto ensure a complete acceptance of test results by operators and notified bodies. In this paper, we will present details on a currently running comparison to settle this issue, and how it differsfrom standard comparisons. Specific strategies had to be adopted to make the experimental results consistent and comparable. The refuelling operating conditions can affect the outcome from the comparison and need to be taken into account. All these points are being addressed in this paper and are part of the comparison protocol. The aim is that in the end, based on the comparison results and the applied strategy, participants will be able to declare certified measurement capabilities to the BIPM.

M. A. de Huu, R. Maury
Design and calibration of critical flow Venturi nozzles for high-pressure hydrogen applications

In this paper, we present the strategy behind the design and manufacture of sets of Critical Flow Venturi Nozzles (CFVN) with various sizes, shapes and surface roughnesses, as well as their dimensional calibration to test the applicability of ISO 9300 for high-pressure hydrogen aplications. Some of the built nozzles and nozzle holders will be used for high-pressure measurements with hydrogen and underwent a baseline metrological check at lower pressure using inert gases to ensure that their low-pressure characteristics are known before performing the measurements with high-pressure hydrogen. Furthermore, all the nozzles are being dimensionally calibrated using an ultra-precise 3D coordinate measuring machine and will yield a database of reference data for these nozzles. As there are currently no test rigs with traceable standards that are able to directly perform the calibration of CFVN with high-pressure hydrogen, an alternative method needed to be developed and a traceability scheme with an expected uncertainty around 1 % using a calibrated Coriolis meter with hydrogen is presented.

Bruno Góbi Santolin, Márcio Ferreira Martins, Ramon Silva Martins, Fernando Augusto Ramos
CFD Verification through comparison with LDP measurements of underexpanded gas leak.

A numerical model was performed to represent the expansion phenomenon resulting from the leakage of pressurized gases in a pipe using the Ansys Fluent 2021 R1 software. The free underexpanded jet was produced by a nozzle with an outlet diameter of operating at a stagnation pressure and temperature respectively equal to and , being compared with the experiment conducted by Eggins and Jackson (1974) for qualitative (visual analysis) and quantitative validation requirements (through the statistical model proposed by Hanna (1993)). After the validation of the proposed numerical model, some important results can be highlighted, such as the temperature, pressure and velocity profiles, showing important regions, such as the barrel-shaped shock and the transition limit region from Mach to Mach denominated“Mach disk”, other important results obtained such as a peak velocity of approximately , the Mach disk position obtained at , a position necessary for the correct plotting of the upstream and downstream velocity profile graphs of the Mach disk. In general, the numerical model managed to meet expectations very well, agreeing with the experiment, it had excellent results for the expected velocity profiles, obtaining maximum average error for each of the compared cases of , and for the worst case, thus validating the proposed numerical model clearly showing the main characteristics of an underexpanded free jet so necessary for leak analysis of pressurized gases.

Haiyang Li, Xinhong Yao,Liang Zhang, Xuejing Li
Study on Numerical Simulation Method of Piston Type Micro Liquid Flow Standard Device

The piston type micro liquid flow standard device is a kind of flow standard device with volume-time method. Because it can easily obtain micro flow due to its working principle, this kind of standard device is widely used in micro flowrate value traceability. In addition, the rapid development of precision machining technology also makes the processing of the piston, the master standard in the piston flow standard device, more and more precise, which plays a significant role in reducing the uncertainty of the whole standard device. In this paper, the simplified geometric model of the piston type micro liquid flow standard device is established by using modeling software, the geometric model is meshed, and finally the grid is solved to obtain the internal flow field of this type of flow standard device.

Bo Wu, Xiaopeng Li, Feng Gao, Tao Meng
Research on Online Value Checking Method of Flow Calibration System Based on Double Master Flowmeter Checking Technology

Whether the measurement performance of flow standard facility is normal or not directly affects the final flow measurement result, and the independent checking of quantity value is the key technical means to ensure the steady and reliable performance of flow calibration system. At present, there is a lack of quantitative verification methods for liquid flow standard facilities, and the existing researches mostly focus on expanding the range of operating parameters of facilities and improving their uncertainty level, etc, while the quantitative verification for flow facilities themselves has not been paid attention to and the relevant verification work has not been widely carried out. Based on the mutual verification of the measured values of double flowmeters, a set of intelligent online value verification method for weighing flow standard facility is designed and established. The theoretical basis of the method is described in detail, and the algorithm theoretical model and criterion are provided. Taking the weighing method micro flow standard facility of the National Institute of Metrology as the research object, the verification experiment test of the verification algorithm is carried out, and the results show that: The proposed online value verification method of flow calibration system has good adaptability and high verification accuracy, and can automatically and real-time monitor the operating status of the system in use, thus greatly improving the stability and reliability of the operation process of the facility, which is worthy of further popularization and application.

Jieqiang Ji, Xuemei Geng, Yan Fang, Xiaojie Wu, Guofu Chen, Ningning Zhang, Zhiyu Fang, Leming Cheng
Investigation on the influence of valve opening on measurement accuracy for ultrasonic flowmeters

The applications of portable clamp-on ultrasonic flowmeters in on-line detection have lots of advantages. However, the measurement accuracy of ultrasonic flowmeters is often affected by various factors, such as pipe characteristics, flow fields and fluid medium. In this work, both experiments and CFD simulations are carried out to study the flow field changing caused by valves, and the influences of valve opening on measurement accuracy for ultrasonic flowmeters. The experiment results showed that, with the decrease of valve opening, the value of repeatability of indication error is increasing. At the same valve opening, with the distance closer to the valve, the deviation of the indication error for multiple measurements is increasing. In the simulation section, an error calculation model based on the numerical simulation is proposed, which is in good agreement with the experimental results. Both ball valve and butterfly valve are calculated, and the following conclusions are obtained: (1) for the ball valve, when the distance of measurement point to valve is less than 10D, the indication error is greatly affected by the orientations of linear velocity extracting (UL). When the valve opening is lower than 50 %, the variation tendency of measurement error at different orientations of UL are relatively random. (2) Compared with the ball valve, the variation tendency of measurement error downstream of the butterfly valve are more regular. With the increase of the distance to the butterfly valve, the measurement error is less affected by the orientations of UL. The correction factors of error at different distances downstream of the butterfly valve are given for different valve opening degrees.

Page 6 of 912 Results 51 - 60 of 9113