CFD Modelling of an Electrically Trace Heated Blanket

2019 ◽  
Author(s):  
Vincent Le Toux ◽  
Stéphanie Harchambois ◽  
Geoffrey Guindeuil ◽  
Romain Vivet ◽  
François-Xavier Pasquet ◽  
...  
Keyword(s):  
Natural Convection ◽  
Full Scale ◽  
Operating Conditions ◽  
Burial Depth ◽  
Test Results ◽  
Cfd Modelling ◽  
Joule Effect ◽  
Hydrate Dissociation ◽  
Cfd Models ◽  
The Impact

Abstract The Electrically Trace Heated Blanket (ETH-Blanket) is a new offshore intervention/remediation system currently in development by TechnipFMC for the efficient remediation of plugs due to hydrates or wax in subsea production and injection flowlines. The ETH-Blanket consists of a network of heating cables placed underneath an insulation layer which is laid onto the seabed above the plugged flowline. By applying electrical power to the cables, heat is generated by Joule effect which warms up the flowline content until hydrate dissociation or wax plug remediation through softening or complete melting. As part of a Joint Industry Project (JIP) between TechnipFMC, Shell and Total, full-scale thermal testing of an ETH-Blanket prototype was carried out in Artelia facilities (Grenoble, France). This testing was performed to verify the capability of the ETH-Blanket system to increase the temperature of the fluid inside a pipe sample above a target temperature (hydrate dissociation temperature or wax disappearance temperature) for various conditions. The impact of lateral misalignment of the ETH-blanket on the pipe and of the pipe burial depth were studied. Moreover, the tests were carried out on two pipe samples, with different designs and insulation properties. CFD models of the test set-up have been built to replicate the thermal behaviour of the ETH-Blanket prototype. Once validated against the test results, the final aim of CFD modelling is to be able to calculate the performances of the system in real subsea conditions. The modelling of the prototype includes a 3D geometry of the system including the soil, natural convection of water between the ETH-blanket and the pipe sample and natural convection of fluid in the pipe sample. The present paper focuses on the CFD work performed to match the full-scale thermal test results and to predict the ETH-Blanket performances for real subsea operating conditions. It will describe the various CFD models used, the sensitivities and findings in terms of local and global heat transfer and flow effects and the comparison to the experimental data.

Full Scale Thermal Testing of a New Flowline Intervention System

2019 ◽  
Author(s):  
Stéphanie Harchambois ◽  
Vincent Le Toux ◽  
Geoffrey Guindeuil ◽  
Romain Vivet ◽  
François-Xavier Pasquet ◽  
...  
Keyword(s):  
Electrical Power ◽  
Data Gathering ◽  
Full Scale ◽  
Thermal Testing ◽  
Burial Depth ◽  
Joule Effect ◽  
Hydrate Dissociation ◽  
Heating Efficiency ◽  
Cfd Models ◽  
The Impact

Abstract The Electrically Trace Heated Blanket (ETH-Blanket) is a new offshore intervention/remediation system currently in development by TechnipFMC for the efficient remediation of plugs due to hydrates or wax in subsea production and injection flowlines. The ETH-Blanket consists of a network of heating cables placed underneath an insulation layer which is laid onto the seabed above the plugged flowline. By applying electrical power to the cables, heat is generated by Joule effect which warms up the flowline content until hydrate dissociation or wax plug remediation through softening or complete melting. As part of a Joint Industry Project (JIP) between TechnipFMC, Shell and Total, full-scale thermal testing of an ETH-Blanket prototype was carried out in Artelia facilities (in Grenoble, France). This testing was performed to verify the capability of the ETH-Blanket system to increase the temperature of the fluid inside a pipe sample above a target temperature (hydrate dissociation temperature or wax disappearance temperature) for various conditions. The impact of lateral misalignment of the ETH-blanket on the pipe and of the pipe burial depth were studied. Moreover, the tests were carried out on two pipe samples, with different designs and insulation properties. In parallel, CFD models of the test set-up were built to replicate the thermal behaviour of the ETH-Blanket. The combination of these models with the measured heating efficiency of the prototype allowed characterising the performances of the system in real subsea conditions. This paper presents the description of the full scale thermal testing conditions. Results of the different tests are detailed and the impact of the different parameters on the ETH-Blanket thermal performances are assessed, focusing on natural convection effects, thermal losses and the overall data gathering process.

scholarly journals Chart for Thermoelectric Systems Operation Based on a Ternary Diagram for Bithermal Systems

Entropy ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 666
Author(s):  
Julien Ramousse ◽  
Christophe Goupil
Keyword(s):  
Heat Pump ◽  
Heat Engine ◽  
Ternary Diagram ◽  
Operating Conditions ◽  
Thermal Dissipation ◽  
Maximum Efficiency ◽  
Joule Effect ◽  
Parametric Curve ◽  
Thermoelectric Systems ◽  
The Impact

Thermoelectric system’s operation needs careful attention to ensure optimal power conversion depending on the application aims. As a ternary diagram of bithermal systems allows a synthetic graphical analysis of the performance attainable by any work-heat conversion system, thermoelectric systems operation is plotted as a parametric curve function of the operating conditions (electric current and reservoirs’ temperature), based on the standard model of Ioffe. The threshold of each operating mode (heat engine, heat pump, thermal dissipation, and forced thermal transfer), along with the optimal efficiencies and powers of the heat pump and heat engine modes, are characterized graphically and analytically as a function of the material properties and the operating conditions. The sensibility of the performance aims (maximum efficiency vs. maximum power) with the operating conditions is, thus, highlighted. In addition, the specific contributions of each phenomenon involved in the semiconductor (reversible Seebeck effect, irreversible heat leakage by conduction and irreversible thermal dissipation by Joule effect) are discussed in terms of entropy generation. Finally, the impact of the exo-irreversibilities on the performance is analyzed by taking the external thermal resistances into account.

Facing the Challenges in CFD Modelling of Multistage Axial Compressors

2017 ◽  
Author(s):  
Lorenzo Cozzi ◽  
Filippo Rubechini ◽  
Michele Marconcini ◽  
Andrea Arnone ◽  
Pio Astrua ◽  
...  
Keyword(s):  
Steady State ◽  
Axial Compressor ◽  
Turbulence Models ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Cfd Modelling ◽  
Main Research ◽  
Axial Compressors ◽  
Rotor Stator Interaction ◽  
The Impact

Multistage axial compressors have always been a great challenge for designers since the flow within these kind of machines, subjected to severe diffusion, is usually characterized by complex and widely developed 3D structures, especially next to the endwalls. The development of reliable numerical tools capable of providing an accurate prediction of the overall machine performance is one of the main research focus areas in the multistage axial compressor field. This paper is intended to present the strategy used to run numerical simulations on compressors achieved by the collaboration between the University of Florence and Ansaldo Energia. All peculiar aspects of the numerical setup are introduced, such as rotor/stator tip clearance modelling, simplified shroud leakage model, gas and turbulence models. Special attention is payed to the mixing planes adopted for steady-state computations because this is a crucial aspect of modern heavy-duty transonic multistage axial compressors. In fact, these machines are characterized by small inter-row axial gaps and transonic flow in front stages, which both may affect non-reflectiveness and fluxes conservation across mixing planes. Moreover, the high stage count may lead to conservation issues of the main flow properties form inlet to outlet boundaries. Finally, the likely occurrence of partspan flow reversal in the endwall regions affects the robustness of non-reflecting mixing plane models. The numerical setup has been validated on an existing machine produced and experimentally tested by Ansaldo Energia. In order to evaluate the impact on performance prediction of the mixing planes introduced in the steady-state computation, un-steady simulations of the whole compressor have been performed at different operating conditions. These calculations have been carried out both at the compressor design point and close to the surge-line to evaluate the effect of rotor/stator interaction along the compressor working line.

Applying CFD modelling in order to enhance water treatment reactors efficiency: example of the ozonation process

2001 ◽  
Vol 1 (4) ◽  
pp. 125-130 ◽  
Author(s):  
Z. Do-Quang ◽  
A. Cockx ◽  
J.M. Laîne ◽  
M. Roustan
Keyword(s):  
Water Treatment ◽  
Full Scale ◽  
Operating Conditions ◽  
Plant Design ◽  
Cfd Modelling ◽  
Major Step ◽  
Oxidation Processes ◽  
Treatment Train ◽  
Scale Design ◽  
Ozonation Process

Disinfection/oxidation processes are a major step in the water treatment train. As high levels of inactivation or removal of pathogens and micropolluants are aimed at the design and optimized operating conditions are crucial issues for the reliability of the treatment and cost control. In this context, using computational fluid dynamics allows better evaluation of the efficiency of the treatment and guarantees its performance prior to full-scale design. Examples are given in this paper of the capability of the numerical tool in order to propose an optimized solution for a refurbishment or a new plant design. The full-scale realization confirmed the predicted quality benefit.

Performance Testing of Microturbine Generator System Fueled by Biodiesel

2007 ◽  
Author(s):  
Hsiao-Wei D. Chiang ◽  
I-Che Chiang ◽  
Hsin-Lung Li
Keyword(s):  
Performance Testing ◽  
Rotating Disk ◽  
Operating Conditions ◽  
Biodiesel Fuel ◽  
Exhaust Gas ◽  
Test Results ◽  
Generator System ◽  
Distributed Power Generation ◽  
Ceramic Disk ◽  
The Impact

Using microturbine generator systems for distributed power generation has become the recent trend. To face the impact of the global energy crisis, one of the options is to use biofuels including biodiesel. To this end, this program is to perform study on biodiesel microturbine testing and analysis. A 150kW microturbine generator set with twin rotating disk regenerators was used. Designed as a vehicular microturbine engine, the twin rotating ceramic disk regenerators dramatically improve fuel consumption by transferring heat energy from the exhaust gas stream to compressor discharge. This paper involved testing of the microturbine generator set at different load conditions using 10%–30% biodiesel fuel. A software program was used to predict the performance of the microturbine generator set at different operating conditions in order to compare with the test results. Both biodiesel and petrodiesel fuels are used on the microturbine generator system in this study and the results will be compared.

scholarly journals CFD Modeling Analysis of Mechanical Draft Cooling Tower

2008 ◽  
Author(s):  
Si Y. Lee ◽  
James S. Bollinger ◽  
Alfred J. Garrett ◽  
Larry D. Koffman
Keyword(s):  
Water Droplet ◽  
Cooling Tower ◽  
Waste Heat ◽  
National Laboratory ◽  
Ambient Air ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Test Results ◽  
Savannah River ◽  
The Impact

Industrial processes use mechanical draft cooling towers (MDCT’s) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional momentum, energy, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was benchmarked against the literature data and the SRS test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed modeling and test results will be presented here.

Evaluating Abdominal Injury in Impacts with Workstation Tables

2005 ◽  
Vol 1908 (1) ◽  
pp. 205-213 ◽  
Author(s):  
Daniel Parent ◽  
David Tyrell ◽  
Benjamin Perlman ◽  
Peter Matthews
Keyword(s):  
Injury Risk ◽  
Full Scale ◽  
Abdominal Injury ◽  
Test Results ◽  
The United Kingdom ◽  
Hybrid Iii ◽  
Protection Strategies ◽  
Scale Test ◽  
Thoracic And Abdominal ◽  
The Impact

In rail passenger seating arrangements with workstation tables, there is a risk of serious thoracic and abdominal injury. Strategies to mitigate this injury risk are being developed through a cooperative agreement between the U.S. Federal Railroad Administration and the Rail Safety and Standards Board of the United Kingdom. The approach to developing the protection strategies involves collision investigations, computer simulations of the occupant response, and full-scale testing. During the train collision in Placentia, California, on April 23, 2002, many occupants hit workstation tables. The investigation indicated the likely modes of injury caused by the impact, the most traumatic being damage to the liver and spleen. A MADYMO computer simulation was created to estimate the loads and accelerations imparted on the occupants that brought about these injuries. Two experiments were designed and executed on a full-scale impact test with an occupant environment similar to the Placentia collision. These experiments incorporated advanced anthropomorphic test devices (ATDs) with increased abdominal instrumentation. The THOR (test device for human occupant restraint) ATD showed a more humanlike impact response than did the Hybrid III Railway Safety ATD. The full-scale test results are used to refine a MADYMO model of the THOR ATD to evaluate improved workstation tables. The occupant protection strategy that will be developed requires that the table remain rigidly attached to the car body and includes a frangible edge with a force–crush characteristic designed to minimize the abdominal load and compression. MADYMO simulations of this table design show a significantly reduced risk of severe abdominal injury.

Truck Tire Operating Temperatures on Flat and Curved Test Surfaces

2005 ◽  
Vol 33 (3) ◽  
pp. 156-178 ◽  
Author(s):  
T. J. LaClair ◽  
C. Zarak
Keyword(s):  
Flat Surface ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Load Pressure ◽  
Truck Tire ◽  
Endurance Testing ◽  
Operating Temperatures ◽  
The Impact ◽  
Tread Rubber ◽  
Cylindrical Test

Abstract Operating temperature is critical to the endurance life of a tire. Fundamental differences between operations of a tire on a flat surface, as experienced in normal highway use, and on a cylindrical test drum may result in a substantially higher tire temperature in the latter case. Nonetheless, cylindrical road wheels are widely used in the industry for tire endurance testing. This paper discusses the important effects of surface curvature on truck tire endurance testing and highlights the impact that curvature has on tire operating temperature. Temperature measurements made during testing on flat and curved surfaces under a range of load, pressure and speed conditions are presented. New tires and re-treaded tires of the same casing construction were evaluated to determine the effect that the tread rubber and pattern have on operating temperatures on the flat and curved test surfaces. The results of this study are used to suggest conditions on a road wheel that provide highway-equivalent operating conditions for truck tire endurance testing.

Experimental study of the strength and durability of metal-composite high-pressure tanks

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 49-56 ◽  
Author(s):  
A. M. Lepikhin ◽  
V. V. Moskvichev ◽  
A. E. Burov ◽  
E. V. Aniskovich ◽  
A. P. Cherniaev ◽  
...  
Keyword(s):  
High Pressure ◽  
Strain State ◽  
Full Scale ◽  
Fracture Mechanisms ◽  
Metal Composite ◽  
Test Results ◽  
Stress Strain ◽  
Pneumatic Pressure ◽  
Stress Strain State ◽  
Composite Tank

The results of unique experimental studies of the strength and service life of a metal-composite high-pressure tank are presented. The goal of the study is to analyze the fracture mechanisms and evaluate the strength characteristics of the structure. The methodology included tests of full-scale samples of the tank for durability under short-term static, long-term static and cyclic loading with internal pneumatic pressure. Generalized test results and data of visual measurements, instrumental and acoustic-emission control of deformation processes, accumulation of damages and destruction of full-scale tank samples are presented. Analysis of the strength and stiffness of the structure exposed to internal pneumatic pressure is presented. The types of limiting states of the tanks have been established experimentally. Change in the stress-strain state of the tank under cyclic and prolonged static loading is considered. Specific features of the mechanisms of destruction of a metal-composite tank are determined taking into account the role of strain of the metal liner. The calculated and experimental estimates of the energy potential of destruction and the size of the area affected upon destruction of the tank are presented. Analysis of test results showed that the tank has high strength and resource characteristics that meet the requirements of the design documentation. The results of the experiments are in good agreement with the results of numerical calculations and analysis of the stress-strain state and mechanisms of destruction of the metal-composite tank.

Model estimates of the results of diabetes patients using modern glucometers with tri-color technology for displaying test results

2019 ◽  
pp. 81-89
Author(s):  
Larisa Dmitrievna Popovich ◽  
Svetlana Valentinovna Svetlichnaya ◽  
Aleksandr Alekseevich Moiseev
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 1 Diabetes ◽  
Economic Benefits ◽  
Test Results ◽  
Self Monitoring ◽  
Patients With Diabetes ◽  
The Impact

Diabetes – a disease in which the effect of the treatment substantially depends on the patient. Known a study showed that the use of glucometers with the technology of three-color display of test results facilitates self-monitoring of blood sugar and leads to a decrease in glycated hemoglobin (HbAlc). Purpose of the study: to modeling the impact of using of a glucometer with a color-coded display on the clinical outcomes of diabetes mellitus and calculating, the potential economic benefits of reducing the hospitalization rate of patients with diabetes. Material and methods. Based on data from two studies (O. Schnell et al. and M. Baxter et al.) simulation of the reduction in the number of complications with the use of a glucometer with a color indication. In a study by O. Schnell et al. a decrease of HbA1c by 0.69 percent is shown when using the considered type of glucometers, which was the basis of the model. Results. In the model, the use of a glucometer with a color-coded display for type 1 diabetes led to a decrease in the total number of complications by 9.2 thousand over 5 years per a cohort of 40 thousand patients with different initial levels of HbA1c. In a cohort of 40 thousand patients with type 2 diabetes, the simulated number of prevented complications was 1.7 thousand over 5 years. When extrapolating these data to all patients with diabetes included in the federal register of diabetes mellitus (FRD), the number of prevented complications was 55.4 thousand cases for type 1 diabetes and 67.1 thousand cases for type 2 diabetes. The possible economic effect from the use of the device by all patients with a diagnosis of diabetes, which are included in the FRD, estimated at 1.5 billion rubles for a cohort of patients with type 1 diabetes and 5.3 billion rubles for patients with type 2 diabetes. Conclusion. Improving the effectiveness of self-monitoring, which is the result of the use of glucometers with color indicators, can potentially significantly reduce the incidence of complications in diabetes and thereby provide significant economic benefits to society.

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