scholarly journals Development of a dynamic gravimetric calibration method for liquid water flow metering

2019 ◽  
Author(s):  
Florestan Ogheard
Keyword(s):  
Water Flow ◽  
Liquid Water ◽  
Gravimetric Method ◽  
Short Review ◽  
Calibration Method ◽  
Reference Laboratory ◽  
Flow Rates ◽  
Flow Generator ◽  
Micro Flow ◽  
Feasibility Test

According to its mission of national reference laboratory, LNE-CETIAT maintains and develops the French standard for liquid water flow meters calibration from 1g.h-1 to 36 t.h-1. The reference calibration facilities at LNE-CETIAT are historically based on the flying start and stop gravimetric method. Because of the specificity of micro-flow rates, two separated and dedicated calibration benches are used for flow rates from 1 g.h-1 to 10 kg.h-1 on one side, and from 8 kg.h-1 to 36 t.h-1 on the other side. Continuous improvement of the calibration capabilities pushes LNE-CETIAT to upgrade the existing methods toward a dynamic measurement of the reference flow rate, in the scope of EURAMET EMPIR "METROWAMET" JRP in which CETIAT is a partner of the consortium. After a short review of the state of the art and a description of the current LNE-CETIAT's, this paper will first present the development of a dynamic liquid flow generator required to ensure the measurand's representability. In a second part, the development of a dedicated and traceable measurement system, based on the existing gravimetric test rig, is described. Finally, the first feasibility test is presented and future developments are proposed.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

scholarly journals Comparison of Optimization-Regulation Algorithms for Secondary Cooling in Continuous Steel Casting

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 237
Author(s):  
Michal Brezina ◽  
Tomas Mauder ◽  
Lubomir Klimes ◽  
Josef Stetina
Keyword(s):  
Convergence Rate ◽  
Water Flow ◽  
Steel Casting ◽  
Casting Process ◽  
Continuous Steel Casting ◽  
Continuous Steel ◽  
Cooling Zone ◽  
Secondary Cooling ◽  
Flow Rates ◽  
Secondary Cooling Zone

The paper presents the comparison of optimization-regulation algorithms applied to the secondary cooling zone in continuous steel casting where the semi-product withdraws most of its thermal energy. In steel production, requirements towards obtaining defect-free semi-products are increasing day-by-day and the products, which would satisfy requirements of the consumers a few decades ago, are now far below the minimum required quality. To fulfill the quality demands towards minimum occurrence of defects in secondary cooling as possible, some regulation in the casting process is needed. The main concept of this paper is to analyze and compare the most known metaheuristic optimization approaches applied to the continuous steel casting process. Heat transfer and solidification phenomena are solved by using a fast 2.5D slice numerical model. The objective function is set to minimize the surface temperature differences in secondary cooling zones between calculated and targeted surface temperatures by suitable water flow rates through cooling nozzles. Obtained optimization results are discussed and the most suitable algorithm for this type of optimization problem is identified. Temperature deviations and cooling water flow rates in the secondary cooling zone, together with convergence rate and operation times needed to reach the stop criterium for each optimization approach, are analyzed and compared to target casting conditions based on a required temperature distribution of the strand. The paper also contains a brief description of applied heuristic algorithms. Some of the algorithms exhibited faster convergence rate than others, but the optimal solution was reached in every optimization run by only one algorithm.

https://fsri.org/research-update/fsri-releases-report-residential-flashover-prevention-reduced-water-flow-phase-1

2020 ◽  
Author(s):  
Daniel Madrzykowski ◽  
◽  
Nick Down
Keyword(s):  
Water Flow ◽  
Test Structure ◽  
Low Flow ◽  
Flowing Water ◽  
Water Spray ◽  
Water Supplies ◽  
Flow Rates ◽  
Prevention System ◽  
Reduced Water ◽  
Fire Experiments

This study was designed to be an initial step to investigate the potential of low flow nozzles as part of a retrofit flashover prevention system in residential homes with limited water supplies. Not all homes have water supplies that can meet the needs of a residential sprinkler system. Current alter- natives, such as including a supplemental tank and pump, increase the cost of the system. These homes could benefit from an effective fire safety system with lower water supply requirements. The experiments in this study were conducted in a steel test structure which consisted of a fire room attached to a hallway in an L-shaped configuration. Three types of experiments were conducted to evaluate nozzles at different flow rates and under different fire conditions. The performance of the nozzles was compared to the performance of a commercially available residential sprinkler. The first set of experiments measured the distribution of the water spray from each of the nozzles and the sprinkler. The water spray measurements were made without the presence of a fire. The other two sets of experiments were fire experiments. The first set of fire experiments were designed to measure the ability of a water spray to cool a hot gas layer generated by a gas burner fire. The fire source was a propane burner which provided a steady and repeatable flow of heat into the test structure. Two water spray locations were examined, in the fire room and in the middle of the hallway. In each position, the burner was shielded from the water spray. The results showed that for equivalent conditions, the nozzle provided greater gas cooling than the sprinkler. The tests were conducted with a fire size of approximately 110 kW, and water flow rates in the range of 11 lpm (3 gpm) and 19 lpm (5 gpm). The second set of fire experiments used an upholstered sofa as the initial source of the fire with the water spray located in the same room. As a result of the compartment size and water spray distribution, the nozzle flowing water at 23 lpm (6 gpm) provided more effective suppression of the fire than the sprinkler flowing 34 lpm (9 gpm) did. The nozzle was similarly effective with the ignition location moved 1.0 m (3.2 ft) further away. However, the nozzle failed to suppress the fire with a reduced water flow rate of 11 lpm (3 gpm). The results of this limited study demonstrate the potential of low flow nozzles, directly flowing water on to the fuel surface, with the goal of preventing flashover. Additional research is needed to examine larger room sizes, fully furnished rooms, and shielded fires to determine the feasibility of a reduced water flow flashover prevention system.

scholarly journals A Field Pilot Study on Treating Groundwater Contaminated with Sulfolane Using UV/H2O2

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1200 ◽  
Author(s):  
Linlong Yu ◽  
Sobhan Iranmanesh ◽  
Ian Keir ◽  
Gopal Achari
Keyword(s):  
Water Flow ◽  
Cost Model ◽  
Electrical Energy ◽  
Pilot Scale ◽  
Process Efficiency ◽  
Contaminated Groundwater ◽  
Operational Parameters ◽  
Flow Rates ◽  
Electrical Energy Per Order ◽  
H2o2 System

Sulfolane is an emerging contaminant in the groundwater and soil nearby gas plants, which has attracted much attention from many researchers and regulatory agencies in the past ten years. In this paper, a field pilot-scale ultraviolet (UV)/hydrogen peroxide (H2O2) system was investigated for treating sulfolane contaminated groundwater. Different groundwater, as well as different operational parameters such as influent sulfolane concentration, H2O2 dosage, and water flow rates, were studied. The results showed that a pilot-scale UV/H2O2 system can successfully treat sulfolane contaminated groundwater in the field, although the presence of iron and other groundwater limited the process efficiency. The lowest electrical energy per order of reduction for treating sulfolane in groundwater by using the pilot-scale UV/H2O2 system was 1.4 kWh m−3 order−1. The investigated sulfolane initial concentrations and the water flow rates did not impact the sulfolane degradation. The enhancement of sulfolane degradation in an open reservoir by adding ozone was not observed in this study. Furthermore, an operational cost model was formulated to optimize the dosage of H2O2, and a stepwise procedure was developed to determine the power necessary of the UV unit.

scholarly journals A Modern Approach to Analyzing the Flowing Pressures of a Two-Phase CBM and Water Column in Producing Wellbores

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xinfu Liu ◽  
Chunhua Liu ◽  
Jianjun Wu
Keyword(s):  
Water Level ◽  
Water Column ◽  
Water Flow ◽  
Flow Rate ◽  
Two Phase ◽  
Modern Approach ◽  
Flow Rates ◽  
Bottom Hole ◽  
Column Pressure ◽  
Phase Column

A modern methodology is presented for the system analysis of flowing pressures in order to forecast the dynamic behavior and solve the forthcoming problems that emerge in two-phase coalbed methane (CBM) wellbores. The proposed methodology involves a numerical integration technique to calculate flowing pressures and pressure drops of CBM and water flow from the bottom hole to the well head. The methodology is validated against full-scale measured data in coalfields. The relationships developed match CBM reservoir behavior and wellbore conditions along the annulus with an overall accuracy of 1.13%. The computation of flowing pressures involves a liquid holdup and kinetic energy term with flow rate increments, a compressibility factor with depth increments, and a friction factor with Reynolds number. The flowing pressures of a two-phase column fully reflect the dynamic flowing performance due to the combined action of the water level, CBM, and water flow rates. The effect of CBM and water column pressures is more obvious than that of CBM column pressures. The pressure ratios of CBM and the water column to the bottom hole decline rapidly with the increase of the dynamic water level. CBM and water flow rates can be improved with increases in CBM and water column pressure for two-phase producing wellbores. The decrease of flowing pressures and increased increment of the pressure drop for the two-phase column are beneficial to CBM desorption and result in the increased CBM and water production. It will control the falling speed of the dynamic water level above CBM and the water column and enhance CBM reservoir productivity. The increases of CBM and water column pressure from 34.6 kPa to 922 kPa and the decreases of pressure in the bottom hole from 2.252 MPa to 1.328 MPa lead to the increases of the CBM flow rate from 3327 m3/d to 6721 m3/d.

scholarly journals Development of physically based liquid water schemes for Greenland firn-densification models

2019 ◽  
Vol 13 (7) ◽  
pp. 1819-1842 ◽  
Author(s):  
Vincent Verjans ◽  
Amber A. Leeson ◽  
C. Max Stevens ◽  
Michael MacFerrin ◽  
Brice Noël ◽  
...  
Keyword(s):  
Water Flow ◽  
Liquid Water ◽  
Preferential Flow ◽  
Greenland Ice Sheet ◽  
Single Domain ◽  
Richards Equation ◽  
Retention Capacity ◽  
Water Percolation ◽  
Physically Based ◽  
Dual Domain

Abstract. As surface melt is increasing on the Greenland Ice Sheet (GrIS), quantifying the retention capacity of the firn layer is critical to linking meltwater production to meltwater runoff. Firn-densification models have so far relied on empirical approaches to account for the percolation–refreezing process, and more physically based representations of liquid water flow might bring improvements to model performance. Here we implement three types of water percolation schemes into the Community Firn Model: the bucket approach, the Richards equation in a single domain and the Richards equation in a dual domain, which accounts for partitioning between matrix and fast preferential flow. We investigate their impact on firn densification at four locations on the GrIS and compare model results with observations. We find that for all of the flow schemes, significant discrepancies remain with respect to observed firn density, particularly the density variability in depth, and that inter-model differences are large (porosity of the upper 15 m firn varies by up to 47 %). The simple bucket scheme is as efficient in replicating observed density profiles as the single-domain Richards equation, and the most physically detailed dual-domain scheme does not necessarily reach best agreement with observed data. However, we find that the implementation of preferential flow simulates ice-layer formation more reliably and allows for deeper percolation. We also find that the firn model is more sensitive to the choice of densification scheme than to the choice of water percolation scheme. The disagreements with observations and the spread in model results demonstrate that progress towards an accurate description of water flow in firn is necessary. The numerous uncertainties about firn structure (e.g. grain size and shape, presence of ice layers) and about its hydraulic properties, as well as the one-dimensionality of firn models, render the implementation of physically based percolation schemes difficult. Additionally, the performance of firn models is still affected by the various effects affecting the densification process such as microstructural effects, wet snow metamorphism and temperature sensitivity when meltwater is present.

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