scholarly journals Challenges of Hot Tapping Into a Sour Gas Transmission Line

2000 ◽  
Author(s):  
Ray Goodfellow ◽  
Rory Belanger
Keyword(s):  
Transmission Line ◽  
Operating Conditions ◽  
New Production ◽  
Line Pressure ◽  
Welding Procedure ◽  
Sour Service ◽  
Line Temperature ◽  
Procedure Development ◽  
Design Pressure ◽  
Sour Gas

Chevron Canada Resources recently completed a hot tap on the Simonette high-pressure sour gas transmission line near Grande Prairie, Alberta. The hot tap was required to bring on new production into the Simonette pipeline without shutting in existing production. The hot tap was completed under full line pressure and gas/condenstate flow during the winter with temperatures averaging −20°C. The design pressure of the 12 “ Gr. 359 Cat II pipeline is 9930 kPa and the line operates at 8200 kPa. The gas in the main transmission line is approximately 2% H2S and 4% CO2. The gas being brought on through the 4″ hot tap tie-in was 21% H2S and 5% CO2. At the tie-in point the transmission line temperature was 3°C. Safely welding on the pipeline under these conditions was a considerable technical challenge. In welding sour service lines it is critical that the final weld hardness be below Vickers 248 micro hardness. This can be very difficult to achieve when welding on a line transporting a quenching medium of gas and condensate. In addition, hydrogen charging of the steel from operation in sour service can lead to hydrogen embrittlement during welding. Ludwig & Associates developed the hot tap weld procedure and extensively tested the procedure to ensure that suitable weld microhardness was achievable under pipeline operating conditions. As part of the procedure development the welder who would perform the hot tap was tested repeatedly until he could confidently and successfully complete the weld. During fieldwork, the welding was rigorously monitored to ensure procedural compliance thereby minimizing the possibility of elevated hardness zones within the completed weldment. This paper will detail with the technical development of the hot tap welding procedure and the successful field implementation.

Analysis of Two Cross Arm of Reactive Powder Concrete Pole Design with Structure Materials in Civil Engineering

2012 ◽  
Vol 568 ◽  
pp. 39-42
Author(s):  
Yu Zhuo Jia ◽  
Li Lin
Keyword(s):  
Mechanical Properties ◽  
Stress State ◽  
Structural Analysis ◽  
Transmission Line ◽  
Operating Conditions ◽  
Reactive Powder Concrete ◽  
Analysis Software ◽  
Technical Performance ◽  
Reduced Height ◽  
Reactive Powder

SAP2000 structural analysis software is used to designed two of 500kV partially prestressed reactive powder concrete pole cross arm; moreover, poles of the two cross arm program have been compared. The results show that the triangular truss cross arm has good mechanical properties, improving the main mate’rial of the stress state, the pole reduced height 10m, by the analysis of the structure shows, this cross arm has higher reliability under the operating conditions, which can be used in 500kV transmission line; from economic and technical performance, the pole cost of this program is greatly reduced, while speeding up the construction progress and improving the comprehensive benefits of the poles in the transmission line.

scholarly journals Kinetic Modeling of Catalytic Olefin Cracking and Methanol-to-Olefins (MTO) over Zeolites: A Review

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 626 ◽  
Author(s):  
Sebastian Standl ◽  
Olaf Hinrichsen
Keyword(s):  
Kinetic Modeling ◽  
Product Distribution ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Reaction Networks ◽  
New Production ◽  
Modeling Methodology ◽  
Steam Cracking ◽  
Increasing Demand ◽  
Future Work

The increasing demand for lower olefins requires new production routes besides steam cracking and fluid catalytic cracking (FCC). Furthermore, less energy consumption, more flexibility in feed and a higher influence on the product distribution are necessary. In this context, catalytic olefin cracking and methanol-to-olefins (MTO) gain in importance. Here, the undesired higher olefins can be catalytically converted and, for methanol, the possibility of a green synthesis route exists. Kinetic modeling of these processes is a helpful tool in understanding the reactivity and finding optimum operating points; however, it is also challenging because reaction networks for hydrocarbon interconversion are rather complex. This review analyzes different deterministic kinetic models published in the literature since 2000. After a presentation of the underlying chemistry and thermodynamics, the models are compared in terms of catalysts, reaction setups and operating conditions. Furthermore, the modeling methodology is shown; both lumped and microkinetic approaches can be found. Despite ZSM-5 being the most widely used catalyst for these processes, other catalysts such as SAPO-34, SAPO-18 and ZSM-23 are also discussed here. Finally, some general as well as reaction-specific recommendations for future work on modeling of complex reaction networks are given.

Calculation of the overhead transmission line conductor temperature in real operating conditions

2020 ◽  
Author(s):  
Ľubomír Beňa ◽  
Vladimír Gáll ◽  
Martin Kanálik ◽  
Michal Kolcun ◽  
Anastázia Margitová ◽  
...  
Keyword(s):  
Transmission Line ◽  
Operating Conditions ◽  
Overhead Transmission Line ◽  
Conductor Temperature

Synchro Phasor Measurement Based Fault Analysis of a Parallel Transmission Line

2014 ◽  
Vol 984-985 ◽  
pp. 996-1004
Author(s):  
D. Miruthula ◽  
Ramachandran Rajeswari
Keyword(s):  
Transmission Line ◽  
Transmission System ◽  
Fault Analysis ◽  
Operating Conditions ◽  
Measurement Unit ◽  
Fault Identification ◽  
Parallel Transmission ◽  
Inference System ◽  
Fault Type ◽  
Phasor Measurement

This paper presents a new method to classify transmission line shunt faults and determine the fault location using phasor data of the transmission system. Most algorithms employed for analyzing fault data require that the fault type to be classified. The older fault-type classification algorithms are inefficient because they are not effective under certain operating conditions of the power system and may not be able to accurately select the faulted transmission line if the same fault recorder monitors multiple lines. An intelligent techniques described in this paper is used to precisely detect all ten types of shunt faults that may occur in an electric power transmission system (double-circuit transmission lines) with the help of data obtained from phasor measurement unit. This method is virtually independent of the mutual coupling effect caused by the adjacent parallel circuit and insensitive to the variation of source impedance. Thousands of fault simulations by MATLAB have proved the accuracy and effectiveness of the proposed algorithm. This paper includes the analysis of fault identification techniques using Artificial Neural Network and Adaptive Neuro-Fuzzy Inference System based protection schemes. The performances of the techniques are examined for different faults on the parallel transmission line and compared with the conventional relay scheme. The results obtained shows that ANFIS based fault identification gives better performance than other techniques.

A Comparison of Two Pressure Control Concepts for Hydraulic Offshore Wind Turbines

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Daniel Buhagiar ◽  
Tonio Sant ◽  
Marvin Bugeja
Keyword(s):  
Wind Turbines ◽  
Feedback Loop ◽  
Pressure Control ◽  
Open Loop ◽  
Operating Conditions ◽  
Offshore Wind ◽  
Feed Forward ◽  
Offshore Wind Turbines ◽  
Line Pressure ◽  
Electrical Generation

Current research in offshore wind turbines is proposing a novel concept of using seawater-based hydraulics for large-scale power transmission and centralized electrical generation. The objective of this paper is to investigate the control of such an open-loop circuit, where a fixed line pressure is desirable for the sake of efficiency and stability. Pressure control of the open-loop hydraulic circuit presents an interesting control challenge due to the highly fluctuating flow rate along with the nonlinear behavior of the variable-area orifice used by the pressure controller. The present analysis is limited to a single turbine and an open-loop hydraulic line with a variable-area orifice at the end. A controller is proposed which uses a combination of feed-forward compensation for the nonlinear part along with a feedback loop for correcting any errors resulting from inaccuracies in the compensator model. A numerical model of the system under investigation is developed in order to observe the behavior of the controller and the advantages of including the feedback loop. An in-depth analysis is undertaken, including a sensitivity study of the compensator accuracy and a parametric analysis of the actuator response time. Finally, a Monte Carlo analysis was carried out in order to rank the proposed controller in comparison to a simple feed-forward controller and a theoretical optimally tuned controller. Results indicate an advantageous performance of the proposed method of feedback with feed-forward compensation, particularly its ability to maintain a stable line pressure in the face of high parameter uncertainty over a wide range of operating conditions, even with a relatively slow actuation system.

scholarly journals Multi-Pass Weld Hydrogen Management to Prevent Delayed Cracking

2000 ◽  
Author(s):  
A. Dinovitzer ◽  
B. Graville ◽  
A. Glover ◽  
N. Pussegoda
Keyword(s):  
Material Selection ◽  
Base Material ◽  
Carbon Equivalent ◽  
Hydrogen Cracking ◽  
Tensile Stresses ◽  
General Base ◽  
Delayed Cracking ◽  
Welding Procedure ◽  
Welding Processes ◽  
Procedure Development

The potential for weld hydrogen cracking, that can also manifest itself as delayed cracking due to formation well after weld deposition, is controlled by three factors: the presence of hydrogen, the susceptibility of the weldment microstructure and tensile stresses. The tensile stresses promoting hydrogen cracking may result from either welding residual stresses or construction or operations based stresses, while the susceptibility of a microstructure is a function of its carbon equivalent and cooling rate. Since all arc welding processes introduce hydrogen into welds to some extent, and in general, base material selection and weld stress levels are not controllable in welding procedure development, the prevention of hydrogen cracking must be accomplished through hydrogen management. This paper describes a means of considering the roles of welding procedure parameters (heat input, preheat, post-heat, inter-pass temperature and time, etc.) in the management of hydrogen in multi-pass welds to preclude delayed cracking. Some results obtained using a multi-pass weld hydrogen and thermal diffusion model are presented to demonstrate the models utility in understanding the effects of welding procedure parameter effects on the risk of delayed cracking.

scholarly journals Calibrated expressions for welding and their application to isotherm width in a thick plate

2014 ◽  
Vol 19 (3) ◽  
pp. 212-220 ◽  
Author(s):  
Gentry Wood ◽  
Shahrukh Al Islam ◽  
Patricio F. Mendez
Keyword(s):  
Thick Plate ◽  
Maximum Error ◽  
Generalized Solutions ◽  
Correction Factors ◽  
Trial And Error ◽  
Minimal Representation ◽  
Welding Procedure ◽  
Procedure Development ◽  
Plate Solution ◽  
Calibration Approach

The present paper introduces a possible solution to the limitations of modern trial and error solutions to welding procedure development. The difficulties of finding generalized solutions to Rosenthal´s equation are discussed and the Minimal Representation and Calibration approach is introduced as a promising procedure for developing these solutions. Dominant factors are identified, with effects from secondary phenomena being taken into account by correction factors. These correction factors are then calibrated and presented in a form that can be easily computed, and therefore be amendable to industry. The approach is then demonstrated by determining the isotherm width from Rosenthal´s thick plate solution. Comparison of the calibrated scaling equations to Rosenthal´s exact solution showed a maximum error of less than 0.8% for any isotherm.

scholarly journals Improvement of protection relay with a single phase autore-closing mechanism based on artificial neural network

2020 ◽  
Vol 11 (1) ◽  
pp. 505
Author(s):  
Zozan Saadallah Hussain ◽  
Ahmed J. Ali ◽  
Ahmed A. Allu ◽  
Rakan Khalil Antar
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Transmission Line ◽  
Circuit Breaker ◽  
Logic Gates ◽  
Operating Conditions ◽  
System Stability ◽  
Phase System ◽  
Three Phase ◽  
Artificial Neural

This paper presents a developed logical tripping scheme to improve conventional protection performance. Adaptive single pole auto reclosure (ASPAR) system is proposed that considers, automatically tripping and reclosing of a multi-shot independent pole technique of a circuit breaker at a predetermined sequence, which can be used to boost the synchronization of the power grid under the transient fault conditions. Moreover, the ASPAR can be utilized to enhance the electrical system stability and reliability at the same operating conditions. Based on the three-phase system, the Artificial neural network (ANN) in this work has been done in order to diagnose and detect healthy and faulted phases. The proposed ANN fault classifier method consists of the logic gates, router circuits, timers, and positive and negative sequence analyses circuit. In addition, it is used to give the ability to recognize a fault type, which by training on the sequence angle values and coordination of the transmission line. Three-phase overhead transmission line including the proposed ASPAR is built in MATLA \SIMULINK environment. Thus the performance ANN-fault classified is tested under different fault conditions. Simulation results show that the proposed ASPAR based on ANN is accurate and well performance. Whereas resultant tripping and reclosing signals of ASPAR are successfully provided that enhances the circuit breaker mechanism under these operating condition.

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