Positive Displacement Flowmeter Research Articles

Evaluation of the Influence of Water Content in Oil on the Metrological Performance of Oil Flow Measurement Systems

According to current Brazilian regulations, if the volumes of oil produced used as a reference for the payment of government shares and third parties contain a water content greater than 2% v/v, these volumes must be arbitrarily increased between 1.44% and 10.89% due exclusively to water content, which has caused operational problems for oil companies such as differences between volumes produced and volumes sold, and additional payments from government shares and third parties. This study aimed to evaluate the metrological performance of oil measurement systems with ultrasonic, Coriolis and positive displacement flow meters when subjected to varied water content, fluid temperature and flow rate conditions using the Design of Experiments and the Response Surface Methodology. The analysis of variance showed that the models presented good fits for the ultrasonic meter (coefficient of determination R2 of 97.96%, p-value of 0.001, and a standard deviation of 5.89 × 10−5); Coriolis meter (R2 of 90.91%, p-value of 0.037, and a standard deviation of 5.88 × 10−5); and positive displacement meter (R2 of 99.07%, p-value of 0.000, and a standard deviation of 4.85 × 10−5). The results of the experiments carried out indicate that the contribution of each parameter analyzed to the metrological performance of the measurement system varies depending on the measurement technology used by the flow meter. However, the fluid temperature proved to be a relevant parameter common to all flow measurement technologies evaluated. All measuring technologies evaluated were influenced by water content in the range of 0% to 10% v/v, with the measurement error being less than 0.2% when compared to a standard positive displacement type meter in almost all experimental conditions. The Coriolis-type flow meter was the one that presented the smallest error among the measuring technologies evaluated.

Risk analysis in conformity assessment of positive displacement flowmeter

Volume measurement of manufactured liquids and liquid raw materials carried out by road tankers (RT) is usual and has economic relevance, justifying the need to ensure metrological reliability. It requires some actions, including choosing suitable standards. In this scenario and considering the practice for type evaluation of measuring instruments, the article proposes a case study, analyzing performance data from a positive displacement meter, a measurement principle widely used as a standard in RT verifications. Current criteria of legal metrology were used: for the 0.3 accuracy class, the maximum permissible error (MPE) is 0.2%. The meter was tested with three different fluids (with different viscosities), and measurement errors were contrasted with the MPE specification, being considered compliant in all situations. On the other hand, risk analysis tools for conformity assessment were incorporated (JCGM 106) based on the different consumer risks, the formulated decision rule, and the measurement uncertainty. Even though, when including the risk analysis, the flowmeter was considered non-compliant, showing the need for a better basis decision using measurement uncertainty in legal metrology actions.

Modified mathematic model of a parallel two-dimensional piston flowmeter

The parallel two-dimensional piston (2D piston) flowmeter is a novel kind of positive displacement flowmeter that has been recently invented and proposed by our research group. Following an overview of the working principle of this flowmeter, a modified mathematic model was carefully established in this paper based on the analysis of the shortcomings of the presented primary model. The churning loss, as the first of two ignored parts in the previous research, is caused by the rollers rotation in oil, and it is considered a part of the torque balance equation in the pressure loss model. Besides, the flow rate of the transient leakage, which comes from the change in the leakage flow rate equation when the 2D piston rotates at a specific angle, was analytically modeled and added to the flow rate distribution equation. By comparing the experimental results from the last study, the modified mathematical model showed to be precise and became more suitable for predicting the flowmeter's performance and enhancing its measuring accuracy.

Validation Method for Digital Flow Meter for Fuel Vendors

Research on the design of fuel measuring device for vendors using Arduino Mega 2560 microcontroller and positive displacement flow meter sensor was conducted. It aimed to design and create a prototype of fuel measuring device for retail traders, and to find error values on the device. The research began with searching for reference books, making hardware and programming, and finally testing the device. The components used were Arduino Mega 2560, positive displacement flow meter sensor, keypad, selenoid valve and 4x20 LCD. The test was performed by comparing the results of the measuring cup to the number displayed on the LCD, followed by reproducibility. Data collection was carried out every volume of 500ml, 1000ml, 1500ml, and 2000ml. The results of the research showed that the error value was 2.24% with the comparison of 1.91%. Several factors affecting the highness of error value were human factor, sensor and device factor, as well as the comparison device being used. Referring to the error value that smaller than 5%, this device is worthy for mass production

Research on a Novel Flowmeter With Parallel Two-Dimensional Pistons as Its Metering Units

Flowmeters play a critical role in hydraulic systems. Following a review of positive displacement flowmeters, we hereby introduce a novel positive displacement flowmeter with parallel two-dimensional pistons as metering units. The working principle involves simultaneously utilizing both the rotational and reciprocation movements of a two-dimensional piston and paralleling two two-dimensional pistons to prevent flow rate fluctuations. Consequently, we established a mathematical model to describe the cam track curves and the displacement of the flowmeter. Meanwhile, the pressure loss is analyzed and the leakage flow rate is estimated to compensate the relative error. Finally, we designed and fabricated a prototype to measure the flow rate with ranges of 1 – 25 L/min. The experimental results show that the prototype has a reading uncertainty of less than 2%, a linearity of around ±3.8% and relative errors of less than ±2.9%. The pressure loss for the prototype increases linearly with the total flow rate and reaches 3 bar at 25 L/min. These characteristics are acceptable considering that this prototype is the first set of two-dimensional piston flowmeters. The shortcomings of this first-generation flowmeter are discussed in the conclusion part to provide guidance to enhance the performance of next-generation prototypes.

Theoretical analysis of the oscillating circular piston positive displacement flowmeter: II numerical solution of equations of motion and comparison with experimental data

In the first part of this paper, Morton et al. [1], we identified the forces and equations required to model the motion of the oscillating piston flowmeter. In this paper we discuss the method of solution, and the computational procedure for modelling the dynamic behaviour of the meter. We have, then, compared the model results with experimental data for variation in: angular velocity, vertical movement and pressure losses. We consider the agreement for variation in the following parameters: flow rate, piston mass, surface coating, lubrication holes, slots in piston skirt, length of up- and downstream pipe work, fluid viscosity and fluid density. We also compare the theory with data from two other sizes of meter. The predictions from the model are generally very accurate, although there is still potential to refine the model and increase further our understanding of the forces which contribute to the motion.

Theoretical analysis of the oscillating circular piston positive displacement flowmeter: I – Modelling the forces acting on the piston

This first part of the paper describes the theoretical modelling of the behaviour of an oscillating circular piston positive displacement flowmeter (also known as the rotary piston flowmeter), by considering the principal forces acting on the piston. These include pressure forces, unsteady flow effects, inlet and outlet flow losses, retarding forces due to thin films and frictional effects. Effects which are too small to affect significantly the dynamic behaviour are not included nor are detailed discussions of liquid leakage. The numerical model lends itself to a time stepping solution which applies the forces at each position and deduces the new position and velocities. Thus the local size of the various forces is calculated at each point in the motion for the precise position of the piston at that moment.In the second part of the paper we set out the calculation process and then demonstrate the validity of our model by comparing it with experimental results. The approach used in this work should lend itself to the modelling of the behaviour of other positive displacement flowmeters.

Final report on the APMP key comparison liquid hydrocarbon flow (APMP.M.FF-K2.a)

A key comparison, APMP.M.FF-K2. was undertaken by the APMP Technical Committee for Fluid Flow, and was piloted by the National Metrology Institute of Japan (NMIJ/AIST). The objective of this key comparison is to demonstrate the degree of equivalence of the hydrocarbon flow standards held at the participating laboratories (CMS, NMIA and NMIJ), to link the key comparison reference value (KCRV) of CCM.FF-K2 and to provide supporting evidence for the calibration and measurement capabilities (CMCs) claimed by the participating laboratories in the Asia-Pacific regions. A screw type positive displacement flow meter was selected as a transfer standard. The performance of the transfer standard and its stability was evaluated from repeated measurements by the pilot institute, NMIJ. The transfer standard showed high performance and good stability since the uncertainty due to the transfer standard was less than quoted uncertainties in the participants. CMS and NMIJ have En values which show consistency with both the relevant KCRV for APMP.M.FF-K2.a and each pair of participants. However some En values for NMIA were from 1 to 1.2, indicating 'alert'.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report on the key comparison of hydrocarbon liquid flow: CCM.FF-K2.2015

Seven laboratories: BEV (Austria), CENAM (Mexico), CMS (Chinese-Taipei), LNE-TRAPIL (France), NEL (United Kingdom), NMIA (Australia), and the pilot lab NMIJ (Japan), participated in the key comparison CCM.FF-K2.2015 for hydrocarbon flow measurement. A screw type positive displacement flow meter was selected as a transfer standard. The calibration stability of the transfer standard was evaluated from repeated measurements by NMIJ and showed standard reproducibility of 0.0035 %. The transfer standard was also thoroughly tested for sensitivity to temperature, viscosity, pressure, and other effects. The uncertainty due to the transfer standard of 0.0080 % was less than the quoted uncertainties of the participants. The key comparison reference values (KCRVs) at Reynolds number of 70 000 and 300 000 were obtained as the weighted mean from the calibration results, and the KCRV at Reynolds number of 100 000 was obtained as the median by using the Monte Carlo method according to Cox's procedure B, since the consistency check at Reynolds number of 100 000 failed at the 95 % confidence level. All participant results selected to determine the KCRVs have En values which show consistency with the evaluated KCRVs.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

普天間飛行場基地跡地計画における緑地計画に関する提案型研究

After the Special Action Committee on Okinawa (SACO) agreement in 1996, Okinawa Prefecture and multiparty have been developing fundamental reuse plan with landowners and citizen. It was changed several times through expert investigations and discussions among them. 2013 plan has come to the halfway point of it. In the plan, some points, especially preservation policy of green, under ground water, and historical heritage in the base were reached consensus among parties. Despite some preservation policy of green and underground water, it has been missing throughout the water balance model study of this area. When people want to save the under ground water to reply the water demand, generally it needs an investigation of current water balance model and water use. So we started a proposal-based study about this research issues. This study aimed to clarify two study objectives. The 1st goal is to calculate exact a water balance model about approx. 1617ha of the 5 watershed areas, A, B, C, D and E, in Ginowan City where the Futenma Air Station is located in. At first, we calculate each land use ratio by GIS to simulate the amount of underground seepage of the rainfall in these 5 watershed areas. It is as for theoretical value. And the other hands, we also researched the amount of several water springs to calculate the amount of underground seepage of the rainfall in these areas as an observation value. The field surveys were held 60 times at each spring waters by flow speed measurement and positive displacement flowmeter. The observation value is in agreement with the theoretical value that we simulate. The finding and the fixed water balance model will contribute to the huge area planning like Futenma. The 2nd goal is to review the open space plan in Futenma reuse plan to fit water demands in these areas by using our water balance model. Because the today's 70% of Futenma Air Station is covered green, it functions as like watershed protection forest. But according to contemporary Reuse plan, after the developing, the green area will decrease than today's area. According to our data gathered by interviewing to farmers and industrial officers who use under ground water and spring water, today's water demand reaches almost 5-62% per supply from the natural condition. We analyzed the demand-supply water balance after the development, it will show over demand at some springs. And the worse more, there are some struggles between farmers in the dry season by the lack of water supply. This result is very important. Before our research, there is no report of the amount of water demand. It means that the demand-supply balance had not been paying little attention. Thus, we proposed to Prefecture Office and City Office to review the open space plan with considering water demands. We explained our analysis in detail at the closed meeting of them. Then almost of our concepts was accepted in the public plan. This study's consequences and contribution are three points. 1) The water balance model of this area is established. 2) The under ground water and spring water demand of this area are calculated. 3) Through continuing discussion with parties, our proposal-based study is accepted in the public reuse plan of Futenma. This work was supported by JSPS KAKENHI Grant Number JP24710168.

Investigation into calibration performance of small volume prover for hydrocarbon flow

Several kinds of commercial flowmeters, namely, Coriolis flowmeters, turbine meters, ultrasonic flowmeters, and positive displacement flowmeters, have been calibrated using the primary standard for hydrocarbon flow measurement in Japan (which is based on static and gravimetric methods with a flying start and finish) and a small volume prover (SVP) at the same calibration condition in order to investigate the performance of the SVP. The differences in calibration results for the mechanical flowmeters between the primary standard and the SVP apparently depend on the flow rate, although the results show agreement within 0.04%. The computer-based flowmeters, which have a time delay in the output pulse signal, indicated larger differences due to the effect of the sudden flow rate change caused by the proving action of the SVP at larger flow damping times.

A Rotor Speed Sensor of Cycloid Rotor Flowmeter

Positive displacement flowmeters (PDFs) are highly accurate flowmeters that are relatively insensitive to the upstream velocity distribution and fluid viscosity. Rotor speed sensors are the key components of a PDF. This paper presents the structure of a non-contact rotor speed ​​sensor which can be used in cycloid rotor flowmeter and other PDFs. The sensor outputs a square wave which contains the speed information of the rotors. The key parameters of the rotor speed sensor are analyzed in this paper and a prototype was fabricated to confirm the rotor speed sensor work well.

Experimental investigation of an oscillating circular piston positive displacement flowmeter: II – Leakage flows and wear tests

Experimental data from an oscillating circular piston positive displacement flowmeter are described which focused on leakage flows and wear. This is the second part of a two part paper on the experimental tests, the first part concerned piston movement and pressure loss. In this paper the leakage across the meter is reported for key parameters including: flow rate, liquid density and viscosity, mass of circular piston, surface coating and length of connection pipes. In addition to the average leakage over a period of time, the leakage past a stationary circular piston was measured during a simulated oscillation. Wear tests were run for both stainless steel and carbon pistons to identify the affected areas of piston and chamber.

Experimental investigation of an oscillating circular piston positive displacement flowmeter: I – Piston movement and pressure losses

Tests of an oscillating circular piston positive displacement flowmeter are described which focused on the effect on pressure drop across the meter of variation in key parameters. These included flow rate, liquid density and viscosity, mass of piston and length of connecting pipes. In addition to the average pressure loss, the pressure loss variation during the oscillation cycle was measured and found to vary with an amplitude dependent on the various parameters. A companion paper reviews data on leakage and wear.

Final report on COOMET.M.FF-S3: Intercomparison measurements in the field of gas flow and volume

The national metrology institutes of Ukraine, Slovakia, Lithuania and Russia conducted a comparison in gas flow from 4 m3/h to 160 m3/h using a positive displacement flow meter as the transfer device. The participants' flow standards are described. The uncertainty contributed to the comparison by the transfer device (0.13%) was assessed by calibrations performed in the pilot laboratory at the beginning and end of the comparison. The standardized degrees of equivalence between each participant's results and the comparison reference values were less than unity except for one flow measurement at one lab where it was 1.07, demonstrating agreement within uncertainty expectations between the participants.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Measurement of liquid film thickness by optical fluorescence and its application to an oscillating piston positive displacement flowmeter

The movement of the circular piston in an oscillating piston positive displacement flowmeter is important in understanding the operation of the flowmeter, and the leakage of liquid past the piston plays a key role in the performance of the meter. The clearances between the piston and the chamber are small, typically less than 60 µm. In order to measure this film thickness a fluorescent dye was added to the water passing through the meter, which was illuminated with UV light. Visible light images were captured with a digital camera and analysed to give a measure of the film thickness with an uncertainty of less than 7%. It is known that this method lacks precision unless careful calibration is undertaken. Methods to achieve this are discussed in the paper. The grey level values for a range of film thicknesses were calibrated in situ with six dye concentrations to select the most appropriate one for the range of liquid film thickness. Data obtained for the oscillating piston flowmeter demonstrate the value of the fluorescence technique. The method is useful, inexpensive and straightforward and can be extended to other applications where measurement of liquid film thickness is required.

The Theoretical Research on the Third Planet Gear Flowmeter for Hydraulic System

In connection with the situation that it is difficult to measure high-pressure flow in hydraulic system. A new type liquid flowmeter was designed in this paper, shown in Fig.1. The gear flowmeter is the positive displacement flowmeter with good features that the measurement precision is very accurate, and it is not restricted by environmental condition. But the gear flowmeter can't be widely used, just because its flow pulsation is large. After deeply studying the gear flowmeter, the author designed a new planet gear flowmeter. The flowmeter has the characteristics that the displacement is large, and the flow pulsation is small, even less than 1%. It can also be used to measure the flow in high pressure hydraulic system.

114 軸流式容積流量計の高精度化

A positive displacement (PD) flowmeters has been used for long years as it can measure volumetric flow directly. Since features of PD's are most exerted in oil related flow measurements, in present society which environmental issues are emphasized, they are required for high accuracy fuel consumption measurements in transport equipment industry such as automotive industry, as well as assuming an important role in cross-border transactions. Also, in recent years, development of secondary standards for JCSS registration is an urgent need; verification of our Screw PD Flowmeter is made, corresponding to such necessity.

Development of Hydrocarbon Flow Calibration Facility as a National Standard

A new primary standard for hydrocarbon flow measurements has been constructed at National Metrology Institute of Japan (NMIJ). The facility was designed for the calibration of hydrocarbon flowmeters in the flow rate range between 3 and 300 m3/h. The expanded uncertainty is estimated to be 0.03 % for volumetric flow rate and 0.02 % for mass flow rate (coverage factor: k = 2). The primary standard is based on a static and gravimetric method with a flying start and finish. The facility consists of two test rigs using kerosene and light oil as working fluids. The test lines for the flowmeters are 50, 100 and 150 mm in diameter and three servo positive displacement meters are used as working standards. To verify the calibration performance, a Coriolis flowmeter, a turbine meter and a positive displacement flowmeter have been calibrated at both test rigs. Furthermore, an international comparison with SP, Swedish National Testing Research Institute, was carried out. A screw-type positive displacement flowmeter was selected as the transfer standard and was calibrated at NMIJ and SP. The result shows that the two national standards at the two institutes agree within the quoted expanded uncertainties.

Build-Up 기법을 이용한 경질유 표준장치의 측정범위 확장

Light Oil Flow Standard System(LOFSS) in Korea Research Institute of Standards and Science(KRISS) was designed for oil flowmeter calibration. In order to extend the flow range from 120 h / ㎥ to 200 h / ㎥, the build-up technique was applied with two positive displacement flowmeters as master flowmeter. The master flowmeters were calibrated against with LOFSS, which has 0.04 % uncertainty of flow quantity determination, then the test flowmeter is calibrated against two master flowmeters. For uncertainty analysis, the repeatability of master flowmeters, the variation of the fluid density and the pipe volume due to temperature change were scrutinized. The contribution of each uncertainty factors to the calibrator and the correlation of each factors were discussed. For investigating the feasibility of uncertainty analysis, a turbine flowmeter as a transfer package was tested with LOFSS and two reference flowmeter. The hypothesis test for both results was coincide with a 95 % significant level. This means that the uncertainty analysis procedure of the calibrator is reasonable and the extension of flow range with master meters was carry out successfully.