scholarly journals Research on collaborative control of double-plunger gas prover based on EtherCAT

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2667-2687
Author(s):  
Zhipeng Xu ◽  
Feipeng Xu ◽  
Dailiang Xie

Piston prover has been widely used as a gas flow standard for its advantages of high accuracy in standard volume, flow stability and repeatability. It has also been employed as the primary gas flow standard in many countries to calibrate meters. However, it is difficult to ensure the uniformity of the inside dimension of the piston, thus the application of conventional piston provers are limited by the maximum calibration flow generated by the piston cylinder volume. In this paper, an improved piston gas prover that mainly consists of two uniform plungers was proposed. Their external diameter constitutes the flow standard. The plungers are driven by servo motor, and the high speed fieldbus EtherCAT has been introduced as the control unit. Hence the two pistons could work collaboratively and operate in three modes: single-piston mode, double-pistons parallel mode, and double-pistons reciprocating mode. Besides generating steady-flow rate, the double-plunger prover can even produce an unsteady-flow rate which could be used to research the dynamic characteristics of flow meters. The structure and working principle of the three modes were carefully introduced. Then experiments for calibrating critical nozzles were carried out, and the results show that the repeatability of the discharge coefficient could be better than 0.06%, and the pressure fluctuation during the process was less than 50 Pa.

Author(s):  
M. Vardelle ◽  
P. Fauchais ◽  
A. Vardelle ◽  
A.C. Léger

Abstract A study of the flattening and cooling of particles plasma-sprayed on a substrate is presented. The characteristic parameters of the splats are linked to the parameters of the impacting particles by using an experimental device consisting of a phase Doppler particle analyzer and a high-speed pyrometer. However, during the long experiments required to get reliable correlations, it was observed that variations in plasma spray operating conditions may alter the particles behavior in the plasma jet. Therefore, a simple and easy-to-use system was developed to control in real time the spray jet. In this paper, the effect of carrier gas flow rate, arc current and powder mass flow rate is investigated. The results on zirconia and alumina powders show the capability of the technique to sense the particle spray position and width.


2020 ◽  
Vol 24 (1) ◽  
pp. 483-500
Author(s):  
Alok Dhaundiyal ◽  
Suraj Bhan Singh

AbstractThis study investigates the behaviour of pyrolysis gas, generated by the thermal decomposing of biomass, in a pilot size reactor. The discreet mathematical model, Lattice Boltzmann, has adopted for mathematical simulation of flow of pyrolysis gas across a porous bed of biomass. The effect of permeability, pressure gradient, voidage of bed, density, temperature, and the dynamic viscosity on the mass flow rate of gas is examined by simulating the gas flow across the fixed bed of hardwood. The Darcy equation is used to estimate the flow rate of gas across the fixed bed of hardwood chips. The temperature in the reactor varies from 32 °C to 600 °C. The reactor has an external diameter of 220 mm and the vertical height of 320 mm. Rockwool insulation is used to prevent heat loss across the reactor. The external heating element of 2 kWe was provided to trigger the pyrolysis reaction. The properties of the system have been recorded by the pressure and temperature sensors, which are retrofitted along the periphery of the reactor. The temperature sensors are located at 80 mm apart from each other; whereas the pressure sensor, placed at the bottom circumference of the reactor. The effect of input parameters on the flow properties of gas is also examined to add up the qualitative assessment of the system to biomass pyrolysis. The polytropic equation of gas is found to be PV2.051 = C, whereas the compressibility of gas varies from 0.0025–0.042 m2·N–1.


Author(s):  
Ameen Malkawi ◽  
Ahmed AlAdawy ◽  
Rajesh Kumar V. Gadamsetty ◽  
Rafael Lastra Melo

Abstract Downhole gas compression technology is an artificial lift method that aims to boost production, maximize recovery and delay onset of liquid loading in gas wells. There are different available compression technologies that can be considered for downhole applications, such as screw, scroll, centrifugal and axial compressors. Selection of the appropriate type mainly depends on expected well performance, ambient conditions, compressor operating envelope, technology characteristics, limitations and size constraints. The objective of this study is to perform a feasibility evaluation of compression solutions applicable for a given set of candidate gas wells. Aerodynamic and hydraulic models are used to determine operating conditions, compressor performance, and to select equipment specifications such as impeller diameter, compressor envelope, shaft HP requirement and number of stages among other parameters. A Pugh analysis is performed for all compression technologies and their characteristics to down-select the most suitable solutions for the given set of wells. The results of the analysis indicated an optimal downhole compression technology that covers most of the gas flow rate requirements and meet the performance expectations. The study also provided critical specifications for the compressor, including high-speed operation needed to provide the required flow rates and compression ratio for a relatively small housing diameter. The study also finds that other technologies may be applicable but only to certain population of wells, as the flow rate spectrum is narrower than the optimal solution at the studied conditions. The analysis for the discarded compression technologies in this study showed relatively significant disadvantages for downhole application when compared to the selected compressor. This study presents a holistic analysis for compression technology selection for gas wells that, as per to the understanding of the authors, is unique in the existing literature of gas well applications.


The use of natural gas in several countries, especially in Indonesia is essential. In gas distribution, every industry and household will not be separated from the measurement system that aims to find out how much natural gas has been used. For this reason, the use of a gas flow meter is necessary. There are several types of gas flow meter can be used in measuring the gas volume. Some types of gas flow meters are gas turbine meters, rotary gas meters and diaphragm gas meters. The primary difference of each type of gas flow meter is the pressure capacity and the speed of the gas flow through it. Flow meter gas turbine is one type of gas flow rate measuring device. There are moving parts consisting of a propeller whose rotation speed is proportional to the flow rate through the flow meter. The type of gas turbine meter is Fluxi 2000/TZ. Fluxi 2000/TZ is designed to measure natural gas and various non-corrosive gases. This tool can be used to measure low gas flow and high gas flow. This tool can also be used to measure flow under various pressure conditions. Corus is the name of the type of gas volume converter. Corus is one instrument that supports the reading process of various gas meters, and one of them is a gas turbine meter. Corus is designed to achieve high levels of performance and accuracy from robust electronic equipment so that the results of reading the fluid volume available on the gas turbine meter can be calculated more accurately regard to the amount of temperature, pressure and compressibility. The working principle and characteristics of the two instruments make the measurements more accurate.


Author(s):  
Christopher R. Martin ◽  
Todd D. Batzel

To address a need for digital gas mixture control, this paper presents a valve design for digital gas flow rate control without a feedback measurement. This design uses a transonic nozzle to regulate a constant flow rate with partial pressure recovery and a pulse-width modulation scheme to actuate flow rate without needing precise location of a throttle body. Experimental results from a prototype are presented showing linear variation of flow with respect to duty cycle and switching frequency consistent with the valve’s theory of operation. Outliers are especially prominant as frequency is varied, and are believed to be due to acoustic effects in the supply line.


2005 ◽  
Vol 12 (04) ◽  
pp. 631-643 ◽  
Author(s):  
ALI MUBARAK ◽  
ESAH BINTI HAMZAH ◽  
MOHD RADZI HJ. MOHD TOFF ◽  
ABDUL HAKIM BIN HASHIM

Cathodic arc evaporation (CAE) is a widely-used technique for generating highly ionized plasma from which hard and wear resistant physical vapor deposition (PVD) coatings can be deposited. A major drawback of this technique is the emission of micrometer-sized droplets of cathode material from the arc spot, which are commonly referred to as "macroparticles." In present study, titanium nitride ( TiN ) coatings on high-speed steel (HSS) coupons were produced with a cathodic arc evaporation technique. We studied and discussed the effect of various nitrogen gas flow rates on microstructural and mechanical properties of TiN -coated HSS coupons. The coating properties investigated in this work included the surface morphology, thickness of deposited coating, adhesion between the coating and substrate, coating composition, coating crystallography, hardness and surface characterization using a field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), X-ray diffraction (XRD) with glazing incidence angle (GIA) technique, scratch tester, hardness testing machine, surface roughness tester, and atomic force microscope (AFM). An increase in the nitrogen gas flow rate showed decrease in the formation of macro-droplets in CAE PVD technique. During XRD-GIA studies, it was observed that by increasing the nitrogen gas flow rate, the main peak [1,1,1] shifted toward the lower angular position. Surface roughness decreased with an increase in nitrogen gas flow rate but was higher than the uncoated polished sample. Microhardness of TiN -coated HSS coupons showed more than two times increase in hardness than the uncoated one. Scratch tester results showed good adhesion between the coating material and substrate. Considerable improvement in the properties of TiN -deposited thin films was achieved by the strict control of all operational steps.


Author(s):  
Romain Lemoine ◽  
Benoit Fillion ◽  
Badie I Morsi

The critical mixing speed for gas entrainment (NCRE), for gas induction (NCRI), induced gas flow rate (QGI) as well as the wavy gas-liquid interfacial area (aWave) of N2 and air were measured in pure toluene and three mixtures of organic liquids (toluene-benzoic acid-benzaldehyde mixtures) under wide ranges of temperatures, T (300-453K), pressures, P (1-15 bar), mixing speeds, N (13.3-23.3Hz) and liquid heights, H (0.171-0.268m) using a 4-liter, see-through agitated autoclave operating as a surface-aeration reactor (SAR) and gas-inducing reactor (GIR).NCRE and NCRI as well as aWave were estimated by analyzing the videos taken with an on-line high-speed Phantom camera through the reactor’s Jerguson windows. In the GIR, QGI was determined using a highly sensitive Coriolis mass flow meter. The Central Composite Statistical Design and analysis technique was used to study the effect of operating conditions on these hydrodynamic parameters.NCRE and NCRI appeared to increase with liquid height and decrease with temperature, whereas, the pressure and gas nature did not significantly affect both parameters. The liquid physicochemical properties were found to strongly affect NCRE and NCRI, and QGI. Increasing mixing speed or decreasing liquid height increased QGI. Increasing temperature or decreasing liquid viscosity initially increased and then decreased QGI. Increasing pressure or gas density on the other hand decreased QGI. Increasing mixing speed and temperature or decreasing liquid height significantly enhanced aWave, as compared to the flat liquid surface. At high pressures, however, lower values of aWave were obtained. Empirical and statistical correlations were also developed to accurately predict NCRE, NCRI, QGI and aWave.


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