Fluid Pressure Drop Testing on Once-Through Boilers

1974 ◽  
Vol 96 (1) ◽  
pp. 56-58
Author(s):  
K. D. Brummel ◽  
A. S. Buchanan
Keyword(s):  
Pressure Drop ◽  
Fluid Pressure ◽  
Supercritical Pressure ◽  
Test Program ◽  
Test Procedures ◽  
Analysis Techniques ◽  
Waterwall Tube

Boiler pressure drop testing has become a useful tool in evaluating the internal waterwall tube deposition on two once-through supercritical pressure boilers. This paper presents the results of five years of testing and describes test procedures, instrumentation requirements, and analysis techniques. The result of this test program has been the minimizing of unit forced outages due to waterwall tube failures.

scholarly journals Pemodelan Penurunan Tekanan Brine di Dalam Pipa Injeksi pada Lapangan Panas Bumi Dieng

Jurnal MIPA ◽  
2017 ◽  
Vol 6 (2) ◽  
pp. 32
Author(s):  
Jeferson Polii
Keyword(s):  
Pressure Drop ◽  
Flow Line ◽  
Chemical Constituents ◽  
Temperature Drop ◽  
Fluid Pressure ◽  
Saturation Temperature ◽  
Geothermal Field ◽  
Chemical Pollution ◽  
Pressure Drops ◽  
Very High

Injeksi brine hasil dari fluida produksi panas bumi digunakan untuk mengisi volume pori batuan reservoir, mencegah penurunan tekanan batuan yang terlalu cepat, dan mencegah polusi panas dan polusi kimia pada lingkungan yang disebabkan oleh kandungan kimia tertentu pada brine. Pada pipa aliran brine terjadi penurunan tekanan fluida sepanjang aliran. Di lapangan panas bumi Dieng, konsentrasi silika sangat tinggi, sehingga penurunan temperatur saturasi memicu desposisi silika. Penurunan tekanan sepanjang pipa aliran brine dari pompa Vertikal Atas (VA) 7 ke pond di pad 29 di lapangan panas bumi Dieng akan menyebabkan penurunan temperatur saturasi, selain juga kehilangan panas secara alami. Perhitungan penurunan tekanan fluida brine berdasarkan perhitungan Harrison-Freeston dan metode dari Zhao, yang dikembangkan dengan algoritma menggunakan Macro Excel. Sehingga dengan memodelkan penurunan tekanan sepanjang pipa alir, dapat dikembangkan untuk perhitungan penurunan temperatur dan pengendapan silika di pipa aliran brine untuk injeksi panas bumi.Brine injection from geothermal production fluids is used to fill reservoir pore rock volumes, preventing rapid rock pressure drops, and preventing heat pollution and chemical pollution in the environment caused by certain chemical constituents in the brine. Decrease fluid pressure along the flow on the brine flow pipe. In the Dieng geothermal field, the silica concentration is very high, so the decrease in saturation temperature triggers the silica desposition. The pressure drop along the brine flow pipe from the Upper Vertical (VA) 7 pump to the pond in pad 29 in Dieng geothermal field will cause a decrease in saturation temperature, as well as natural heat loss. The calculation of the decrease in brine fluid pressure based on Harrison-Freeston calculations and methods of Zhao, developed with algorithms using Macro Excel. By modeling the pressure drop along the flow line, it can be developed for the calculation of temperature drop and deposition of silica in the brine flow pipe for geothermal injection

Validation of Valve Leak Quantification With Non-Intrusive Acoustic Emission Technology

2014 ◽  
Author(s):  
Stan Hale
Keyword(s):  
Acoustic Emission ◽  
Critical Path ◽  
Check Valve ◽  
Leak Rate ◽  
Test Program ◽  
Analysis Techniques ◽  
Water Testing ◽  
Valve Leakage ◽  
The Uk ◽  
Valve Leak

In the late 1980s and early 90s, several companies tested a range of acoustic devices for monitoring valve leakage during the check-valve diagnostic system research performed at the Utah State Water Research Laboratory as part of two separate nuclear-industry-sponsored initiatives. The acoustic sensor technology and analysis techniques evaluated were found helpful but no progress was made in non-intrusively quantifying the leak rate through the valves tested during these programs. Around that same time, oil & gas companies in the UK were experimenting with detection and quantification of valve leakage using acoustic emission (AE) technology. The AE sensors and signal-processing technology selected for the UK oil & gas effort responded to much higher frequencies compared to the sensors and systems used during the nuclear-utility initiative in the U.S. This research led to new products for detection and quantification of valve leakage in oil & gas applications. Because of minimum leak threshold and accuracy concerns, non-intrusive acoustic valve leak measurement has remained an elusive goal for commercial nuclear power. Various general-purpose acoustic tools have been trialed to detect leakage with mixed results because of complications caused by plant and system acoustic characteristics. Several of today’s moderately successful check-valve diagnostic systems employ acoustic sensors and can detect the most likely event representing flow cutoff when a check-valve disc fully closes, but leak-rate quantification with any of these systems is not possible. Correlation methods and other AE analysis techniques that have been developed to quantify leakage in steam systems have been generalized as small, medium, and large leakage classifications with no clear criteria for these levels. During the last couple of years, nuclear-plant engineers responsible for programs for compliance with Appendix J, “Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors,” to Part 50, “Domestic Licensing of Production and Utilization Facilities,” of Title 10, “Energy,” of the Code of Federal Regulations (Appendix J to 10 CFR 50) have made extensive use of a new acoustic valve leak-detection system known as MIDAS Meter®. Appendix J valve testing (also known as Type C testing) requires that sections of nuclear-plant piping be isolated by closing a number of valves, thereby creating a confined pressure boundary. The isolated piping within the boundary is pressurized with approximately 344.7 kilopascals (kPa) [50 pounds per square inch (psi)] of air and the leak-tightness of the boundary is evaluated. When the isolated piping exhibits excess leakage or cannot maintain the test pressure, the valves creating the boundary are evaluated one by one to find the culprit leaker. The process of finding and correcting the problem valve can take from hours to several days and may become an outage critical-path activity. Appendix J engineers have enjoyed considerable success with their newfound ability to quickly and confidently identify the leaking valves with MIDAS Meter® and remove their test programs from the critical path. MIDAS Meter® is a high-frequency acoustic-emission-based system which includes algorithms that convert the acoustic emission signal to leak rate. The basic algorithms were first developed from the field results obtained during the early development work for UK oil & gas operators and refined over the next 20 years. Though not originally validated under a quality-assurance (QA) program of the 10 CFR 50 type, nuclear plants that own MIDAS Meter® have been eager to go beyond simple troubleshooting and use the leak quantification results for nuclear applications, including safety-related decisionmaking. In order to support owners and avoid improper application of this very successful new tool, Score Atlanta embarked on an extensive validation program consistent with 10 CFR Part 50 requirements. A purpose-built leak-test flow loop and valve simulator apparatus were constructed in the Atlanta facility and testing began in early 2013. To support Appendix J users, the air testing was performed first and completed in July 2013. The water testing followed and should be completed in early 2014. Numerous combinations of leak path, leak-path geometry, and differential pressure were created and evaluated during the air phase of the program. Pressure was limited to 1034 kPa [150 psi] for air testing. The water testing includes pressures up to 8,618 kPa [1,250 psi] and a similar number of varying leak paths and pressure test points. This paper discusses the preliminary results of the test program, including any special limitations required for use of AE-derived valve leak results in nuclear safety-related applications. The full results of the test program and guidance for nuclear safety-related use of the technology are expected to be available ahead of the 2014 ASME-NRC Valve Symposium. Paper published with permission.

A three-compartment model of the pulmonary vasculature: effects of vasoconstriction

1983 ◽  
Vol 55 (3) ◽  
pp. 923-928 ◽  
Author(s):  
J. H. Linehan ◽  
C. A. Dawson
Keyword(s):  
Pressure Drop ◽  
Fluid Pressure ◽  
Compartment Model ◽  
Venous Occlusion ◽  
Pulmonary Vasculature ◽  
Lung Lobe ◽  
Prostaglandin F2 Alpha ◽  
Vascular Bed ◽  
Middle Compartment ◽  
The Impact

The venous occlusion experiments provide sufficient data to permit the vascular bed of a dog lung lobe to be mathematically modeled as three serial compartments, each containing a quantifiable resistance separated by equal parallel compliances. To determine how these compartments are related to the sites of vasomotion in the pulmonary vascular bed we investigated the effects of various pulmonary vasomotor stimuli. We found that serotonin, sympathetic nerve stimulation, hypoxia, and prostaglandin F2 alpha increased the pressure drop upstream (arterial) from the site of major lobar compliance. On the other hand, histamine, norepinephrine, epinephrine, and elevation of the cerebrospinal fluid pressure increased the pressure drop downstream (venous) from the site of major lobar compliance. These stimuli either did not affect the pressure drop across the middle compartment or increased it slightly. Thus we conclude that the middle compartment represents vessels located between the muscular arteries and veins including the capillary bed and possibly other small nonmuscular vessels. Further, the average preocclusion pressure in the middle compartment is a microvascular pressure that can be used to evaluate the impact of vasoconstriction on the lobar microcirculation.

Study on the Minimum Drag Coefficient Phenomenon of Supercritical Pressure Water in the Pseudocritical Region

2012 ◽  
Author(s):  
Xianliang Lei ◽  
Huixiong Li ◽  
Shuiqing Yu ◽  
Yifan Zhang ◽  
Tingkuan Chen
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Drag Coefficient ◽  
Supercritical Pressure ◽  
Pressure Drops ◽  
Minimum Drag ◽  
Wide Range ◽  
Pressure Water ◽  
Isothermal Flows ◽  
Supercritical Pressure Water

With the development of supercritical (and even ultra-supercritical) pressure boilers (SCBs) with high capacities, and at the same time, with the consideration of supercritical pressure water-cooled reactors (SCWRs) as one of the six most promising reactor concepts accepted in the Generation IV International Forum (GIF), flow and heat transfer of supercritical water becomes more and more important for both the design and operation safety of the related facilities. Thermo-hydraulic characteristics are among the issues, which are of special significance for the SCBs and SCWRs. It has been found that at supercritical pressures, the hydraulic resistance of water exhibits special characteristics in regions near its pseudo-critical point, which is hereafter called the minimum drag coefficient phenomenon. Experimental investigation was carried out in the present study to investigate further the characteristics of drag coefficient of supercritical pressure water under different conditions. The total pressure drop characteristic of water flowing in smooth tube and internally ribbed tube under the supercritical pressures was measured in experiments with a wide range of operational parameters, such as the system pressures ranging from 23 to 28 MPa, the average heat fluxes varied from 100 kW/m2 to 500kW/m2, and the mass fluxes of water in a range of 600 ∼ 1050 kg/m2s. The experimental data were compared with prediction results calculated by existing common correlations for single phase pressure drops, and large discrepancies were observed between the experimental data and the prediction results. Furthermore, the pressure drops characteristics of supercritical pressure water in cases with different tube arrangement and test conditions were compared with each other, such as that in horizontal tubes and vertical tubes, and that in isothermal flows and in non-isothermal flows. Additionally, this phenomenon observed in the present studies was also analyzed by using computational fluid dynamics technology, and the mechanism of pressure drop variation was reasonably explained. It was found that the deviation appeared between the previously proposed drag coefficient correlations and the present experimental data was mainly owning to ignoring the variation of an existence of the minimum drag coefficient in the pseudo critical region in previous studies, and based on the data obtained in this study, a new correlation for drag coefficient for supercritical pressure water was presented.

On the loading conditions for pore fluid stabilization of failure in crustal rock

2020 ◽  
Author(s):  
Franciscus Aben ◽  
Nicolas Brantut
Keyword(s):  
Pressure Drop ◽  
Shear Failure ◽  
Fluid Pressure ◽  
Confining Pressure ◽  
Pore Fluid ◽  
Failure Zone ◽  
Effective Pressure ◽  
Loading Conditions ◽  
Dynamic Failure ◽  
Pore Fluid Pressure

<p>During shear failure in rock, fracture damage created within the failure zone causes localized dilation, which, under partially drained conditions, results in a localized pore fluid pressure drop. The effective normal stress within the failure zone therefore increases, and with it the fracture and frictional strengths. This effect is known as dilatancy hardening. Dilatancy hardening may suppress rupture propagation and slip rates sufficiently to stabilize the rupture and postpone or prevent dynamic failure. Here, we study the loading conditions at which the rate of dilatancy hardening is sufficiently high to stabilize failure. We do so by measuring the local pore fluid pressure during failure and the rate of dilatancy with slip at a range of confining and pore fluid pressures.</p><p>We performed shear failure experiments on thermally treated intact Westerly granite under triaxial loading conditions. The samples were saturated with water and contained notches to force the location of the shear failure zone. For each experiment, we imposed a different combination of confining pressure and pore fluid pressure, so that the overall effective pressure was either 40 MPa or 80 MPa prior to axial deformation at 10<sup>-6</sup> s<sup>-1</sup> strain rate. Dynamic shear failure was recognized by a sudden audible stress drop, whereas the stress drop during stabilized shear failure took longer and was inaudible. Local pore fluid pressure was measured with in-house developed pressure transducers placed on the trajectory of the prospective failure.</p><p>At effective pressures of 40 MPa and 80 MPa, we observe stabilized failure for a ratio λ (imposed pore fluid pressure over confining pressure) > 0.5. For λ < 0.5, we observe dynamic failure. Of two experiments performed at λ = 0.5 and 80 MPa effective pressure, one showed stabilized failure and one failed dynamically. For λ > 0.5, we observe pore fluid pressure drops in the failure zone of 30-45 MPa for 40 MPa effective pressure, and 60 MPa for 80 MPa confining pressure. The local pore fluid pressure during dynamic failure (λ < 0.5) is 0 MPa, strongly suggesting local fluid vaporization. Of the two experiments at λ = 0.5, the dilation rate with slip is higher for the dynamic failure relative to the stabilized failure.</p><p>We show that with increasing effective pressure, dilatancy hardening increases as the local pore fluid pressure drop during failure becomes larger. For λ < 0.5, dilatancy hardening is insufficient to stabilize failure because the local pore fluid pressure drop is larger than the absolute imposed pore fluid pressure. Near λ = 0.5, small variations in dilatancy control rupture stability. For λ > 0.5, dilatancy hardening is sufficient to suppress dynamic failure.</p>

An Analytical and Experimental Evaluation of the Damping Capacity of Sandwich Beams With Viscoelastic Cores

1967 ◽  
Vol 89 (3) ◽  
pp. 438-443 ◽  
Author(s):  
I. W. Jones ◽  
V. L. Salerno ◽  
A. Savacchio
Keyword(s):  
Previous Investigation ◽  
Equations Of Motion ◽  
Free Vibrations ◽  
Vibration Damping ◽  
Damping Capacity ◽  
Sandwich Beams ◽  
Natural Boundary ◽  
Test Program ◽  
Test Procedures ◽  
Natural Boundary Conditions

A study is made of the free vibrations of sandwich beams with viscoelastic cores. The study, which is a generalization of a previous investigation by the authors [1] includes the equations of motion and natural boundary conditions, derivation of expressions for the modal distribution of damping based upon “small damping” assumptions, numerical examples, and a supporting test program. The generally high values calculated for beams of various materials indicate that this type of construction is efficient for vibration damping applications. It was found, however, that the calculated and test values were not in accord. This lack of agreement signifies the necessity for greater refinement in both analytical methods and test procedures.

A Coating Evaluation Testing Program★

CORROSION ◽  
1958 ◽  
Vol 14 (12) ◽  
pp. 18-24 ◽  
Author(s):  
E. R. ALLEN
Keyword(s):  
Field Performance ◽  
Service Performance ◽  
New Materials ◽  
Test Program ◽  
Test Procedures ◽  
Controlled System ◽  
Field Service ◽  
Laboratory Results ◽  
Laboratory Procedures ◽  
Selection Of

Abstract A program to test and evaluate external pipeline coatings is described. When this program was started ten years ago, many methods and procedures then in use did not give all of the information desired. Field burial tests are lengthly and because of the variable conditions which govern results can neither be controlled nor evaluated with any precision. Only laboratory type tests are suitable for a closely controlled system of coating evaluation. Laboratory results must be correlated with field service performance. This test program was in three phases: First, laboratory procedures and apparatus were developed. Second, commonly used coatings were tested ana laboratory results correlated with field performance data. Third, new materials were tested and their performance compared with coatings in common use. Laboratory and field test procedures and apparatus are described. A discussion on the application of test data to selection of pipeline coatings is included. 2.1.2

scholarly journals Towards an Optimal Pressure Tap Design for Fluid-Flow Characterisation at Microscales

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1086 ◽  
Author(s):  
Tomás Rodrigues ◽  
Francisco Galindo-Rosales ◽  
Laura Campo-Deaño
Keyword(s):  
Pressure Drop ◽  
Soft Lithography ◽  
Rectangular Channel ◽  
Fluid Pressure ◽  
Pressure Sensors ◽  
Optimal Solution ◽  
Channel Length ◽  
Creeping Flow ◽  
Channel Width ◽  
Test Fluid

Measuring fluid pressure in microchannels is difficult and constitutes a challenge to even the most experienced of experimentalists. Currently, to the best of the authors’ knowledge, no optimal solution are being used for the design of pressure taps, nor guidelines concerning their shape and its relation with the accuracy of the readings. In an attempt to address this issue, a parametric study was devised to evaluate the performance of different pressure tap designs, 18 in total. These were obtained by combining three shape parameters: sub-channel width (w) and sub-channel–tap radius (R) or angle (α), while having the sub-channel length kept constant. For each configuration, pressure drop measurements were carried out along several lengths of a straight microfluidic rectangular channel and later compared to an analytical solution. The microchannels were fabricated out of PDMS using standard soft-lithography techniques, pressure drop was measured with differential pressure sensors, the test fluid was DI water and the flow conditions varied from creeping flow up to R e c ∼100. Pressure taps, having smooth contours (characterised by the radius R) and a sub-channel width (w) of 108 μ m , performed the best with results from that of radius R = 50 μ m only falling short of the theory by a mere ∼ 5 % .

Performance Evaluation of a Density Measurement Tool for ESP Applications

2021 ◽  
Author(s):  
Chidirim Ejim ◽  
Jinjiang Xiao
Keyword(s):  
Pressure Drop ◽  
Production Management ◽  
Fluid Pressure ◽  
Density Measurement ◽  
Measurement Tool ◽  
Flow Section ◽  
Outer Diameter ◽  
Deviation Angle ◽  
Flow Monitoring

Abstract Knowledge of fluid densities in oilfield activities is vital during production operations. The information can be used to ascertain changes in the type of produced fluids, determine water cut, gauge equipment performance, etc. This study presents the evaluation of a measurement tool that can be installed with an electric submersible pump (ESP) to measure in-situ fluid densities during production operations. Such tools can also be configured for use in non-ESP applications. The density measurement tool has a 5.62-inch outer diameter, typical of some ESP components, which may be installed in a 7-in, 26 lb/ft casing. The tool consists of two flow sections with a 5-degree deviation angle. Total flow rates from the analysis were varied from 2000 barrels per day (bpd) to 12,000 bpd with water as the operating fluid. Pressure drop data within each flow section of the tool were obtained and the fluid densities determined. The estimated densities were compared with the known densities for water. The results indicate that the pressure drop measurements depend on the entry distance of fluid to the first measurement point within the tool. Other contributing factors include the distance between the measurement sensors and the deviation angle between the flow sections. These factors were optimized by incorporating flow symmetry into and out of the tool to ensure reduced variability of the pressure measurements and thus enable computation of the fluid densities. Overall, incorporating the two flow sections with known deviation angle was beneficial to reduce the complexity of estimating the fluid densities. Therefore, having a simple internal flow architecture in addition to optimized pressure measurement capabilities for each flow section has the potential to estimate fluid densities. Such a tool may be used as a means to measure in-situ and surface fluid densities from flows typical of oilfield production operations. The main benefit is to obtain instantaneous fluid density mesurements for more accurate production monitoring and faster decision-making during production with an ESP. This study presents a tool with a different internal architecture and a method that can be used to estimate fluid densities from flows typical of oilfield production operations. The tool architecture and measurement technique are simple and have the benefit of easy integration into a flow monitoring system. Such systems are of value to oilfield operators and stakeholders to optimize hydrocarbon flow and implement effective production management of field assets.

Sign in / Sign up

Export Citation Format

Share Document