Pipe Line Research Articles

Hydrogen transport in large-scale transmission pipeline networks: Thermodynamic and environmental assessment of repurposed and new pipeline configurations

One key strategy to achieve global climate targets is implementing climate-friendly hydrogen as a versatile energy carrier, commodity, and feedstock in the most energy-intensive sectors. Transmission pipeline networks are suited particularly for connecting primary hydrogen producers and consumers over medium distances to meet the future hydrogen demand in regions that strongly rely on energy imports. Nonetheless, the development and operation of large-scale hydrogen pipeline networks may have various yet unknown impacts on the environment. This work investigates the energetic efficiency and the environmental performance of hydrogen transport via pipeline by means of thermodynamic analysis and life cycle assessment. Pertinent technical specifications for large-scale hydrogen pipeline networks were derived based on the current design of state-of-the-art hydrogen pipelines and compressor stations. Since the energy-efficient operation of the pipeline network is essential for a climate-friendly hydrogen transport, thermodynamic analyses were performed to determine the resulting energy demand. Depending on the impact category considered, there are advantages and trade-offs in aiming for an energy-efficient as well as environmentally friendly hydrogen transport solution. The most decisive parameters to reach these aims are the condition of the line pipe’s inner layer, the applied load capacity, as well as the compression ratios, -stages and -positioning. By varying these parameters and considering multiple transport variants, we recommend three measures for the design and operation of new or repurposed hydrogen pipelines: 1) Installing new smooth line pipes or cleaning existing ones to minimize the roughness of the inner surface; 2) Moderately reducing the load capacity, and 3) Shortening the transport intervals by installing intermediate compressor stations. Ultimately, reducing pressure losses within the pipeline system is crucial for ensuring an energetically efficient as well as environmentally friendly hydrogen transmission via large-scale pipeline networks.

A High Performance Dual Stage Face Detection Algorithm Implementation using FPGA Chip and DSP Processor

A dual stage system architecture for face detection based on skin tone detection and Viola and Jones face detection structure is presented in this paper. The proposed architecture able to track down human faces in the image with high accuracy within time constrain. A non-linear transformation technique is introduced in the first stage to reduce the false alarms in second stage. Moreover, in the second stage pipe line technique is used to improve overall throughput of the system. The proposed system design is based on Xil¬inx’s Virtex FPGA chip and Texas Instruments DSP processor. The dual port BRAM memory in FPGA chip and EMIF (External Memory Interface) of DSP processor are used as interface between FPGA and DSP processor. The proposed system exploits advantages of both the computational elements (FPGA and DSP) and the system level pipelining to achieve real time perform¬ance. The present system implementation focuses on high accurate and high speed face detec¬tion and this system evaluated using standard BAO image database, which include images with different poses, orientations, occlusions and illumination. The proposed system attained 16.53 FPS frame rate for the input image spatial resolution of 640X480, which is 23.4 times faster detection of faces compared to MATLAB implementation and 12.14 times faster than DSP implementation and 2.1 times faster than FPGA implementation.

Battery-Free UHF-RFID Sensors-Based SLAM for In-Pipe Robot Perception

Water utilities across the globe are concerned with the inspection and replacement of buried metallic water pipes due to corrosion-related structural damages. Internal pipe linings are commonly used as a renewal method to improve structural strength as they are regarded to be a less expensive alternative to costly and time-consuming pipe replacements. However, linings are also prone to failure as well. Therefore, water authorities regularly monitor lining performance, where defect evolution over a long period of time is an important parameter to note. It requires an accurate in-pipe robot localization technology. In this article, we propose a novel method for in-pipe robot localization and tag mapping that uses battery-free ultra high frequency (UHF)-radio-frequency identification (RFID) sensor wireless signals. It utilizes a signal mapping approach in combination with a tailored pose-graph simultaneous localization and mapping (SLAM) algorithm. Evaluation results of a field-extracted pipe sample from Sydney Water’s distribution network show that the proposed approach is capable of localizing the robot within 2.5 cm accuracy in a 50-m equivalent pipe with an unknown UHF-RFID distribution. The proposed approach outperformed other reported similar work in the literature.

Artificial neural network models of burst strength for thin-wall pipelines

Burst strength is critical to pipeline design, operation, and integrity management. The Barlow formula with the ultimate tensile stress (UTS) was often used to estimate burst strength of line pipes. To consider the plastic flow effect of pipeline steels, an average shear stress yield criterion was proposed, and the associated Zhu-Leis solution of burst strength was obtained for defect-free pipelines in term of UTS and strain hardening exponent, n, of materials. The Zhu-Leis solution was validated by more than 100 burst tests for various pipeline steels. The Zhu-Leis solution, when normalized by the Barlow strength, is a function of strain hardening rate, n, only. In contrast, experimental burst test data, when normalized by the Barlow strength, are a weak function of UTS and pipe diameter to thickness ratio D/t, in addition to be the function of n. Due to the difficulty of obtaining a closed-from solution using three-parameter regression, machine learning technology is adopted to develop alternative models of burst strength based on a large database of full-scale burst tests. In comparing to the regression, the machine learning method works well for both single and multiple parameters by introducing an artificial neural network (ANN), activation functions and learning algorithm for the network to learn from training data and then make predictions. Three ANN models were developed in this paper for predicting the burst strength of defect-free pipelines. Model 1 has one input variable and one hidden layer with three neurons; Model 2 has three input variables and one hidden layer with five neurons; and Model 3 has three input variables and two hidden layers with three neurons for the first hidden layer and two neurons for the second hidden layer. These three ANN models were then validated by the full-scale test data and evaluated through comparison with the Zhu-Leis solution and the linear regression results. On this basis, the best ANN model was recommended.

Understanding the corrosion of pipe steel due to the adhesion of sulfate reducing bacteria film combined with the deposit layer

In the production of shale gas, solid particles such as gravel and clay can adhere to the pipe wall surface and generate under-deposit corrosion (UDC). Meanwhile, the adhesion of sulfate reducing bacteria (SRB) film can further aggravate the local corrosion problem, which would easily result in the failure of pipe lines. Therefore, understanding the corrosion of the steels when SRB film and deposit layer are co-existed is of highly significance. In this work, UDC in SRB-containing shale gas flowback water was studied by means of wire beam electrode, scanning electron microscope, energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). The results show that SRB can adhere to bare steel to form biofilm and then corrosion occurs. For deposit-covered steel, SRB cannot directly contact the metal matrix due to the barrier effect of the artificial deposit layer, therefore no SRB corrosion was observed. Bare steel and deposit-covered steel can form a galvanic couple, where the deposit-covered steel serves as the anode and the bare steel as the cathode. However, SRB could accelerate the corrosion of bare steel and enhance the cathodic reaction, thus promoting the anodic reaction under the deposit-covered steel.

Analysis of Welding Procedure Specifications for steel line pipe material

This study proposes the welding process steel line pipe material of API5L Grade X52 diameter Ø8 inch SCH80 type, subjected to the good quality of the product by following the Welding Procedure Specifications (WPS). The purpose of welding using WPS is to ensure that the welding process follows the correct stages because the steps are proper. The weld results will be free from defects and safe for line pipes. In order to confirm the WPS quality, the characterisations of macrostructure, microstructure, and mechanical properties were analysed. The welding process results by following the procedure specifications, from macrostructure shown no porosity, and sample without following the welding procedure specifications shown porosity at weld metal position. The tensile test sample following the welding procedure specifications showed high strength and ductility compared with the samples without welding procedure specifications. This phenomenon occurs due to the grain size of the martensitic structure and a little bit of growth compared with a sample without following the welding procedure specifications. Furthermore, the bending test result shows that both samples have no crack at the weld metal position.

Experimental and numerical simulation of formed-in-place pipe liner for repairing water mains with void

The failure pressure of the rehabilitated pressure pipe-lined system is related to several factors including the void in the host pipe. In this paper, the internal pressure resistance test of FIPP (Formed-In-Place Pipe) liner spanning the circular voids of the host pipe is carried out. The relationship among the strain, vertical displacement and internal pressure of the FIPP liner is studied. A three-dimensional finite element model of the host pipeline-FIPP liner system was established based on ABAQUS to investigate the stress distribution disciplinarian of the FIPP lining surface and the stress loading path of critical elements were investigated. Considering the influence of circular voids with different diameters on the failure pressure of FIPP lining pipes, numerical study of DN300 FIPP lining with a wall thickness of 5 mm is carried out. The results show that the hoop stress in the center of the void is always greater than the stress in other positions. Axial rupture is the main failure mode of the FIPP lining under the hoop stress at the center point. The maximum stress criterion is accurate and reliable when used to estimate the failure pressure of the FIPP lining. The larger ratio of void diameter to pipe diameter leads to smaller failure pressure of the lining. These results support further trenchless rehabilitation technology development of FIPP lining design and widespread applications.

Hot Deformation Behavior of C-Mn Steel with Incomplete Recrystallization during Roughing Phase with and without Nb Addition

The objective of the study is to improve understanding of the practical role of niobium (Nb) in the case of industrial inconsistent rolling processes such as the rolling of heavy gauge plates where a lower stored energy rolling practice will result in a less stable and less repeatable static recrystallization (SRX) activation that prevents complete recrystallization. In the current study, these variabilities are validated by comparing the mean flow stress (MFS) indirectly determined from the rolling force measured on a reverse four-high rolling mill stand. The material resistance to deformation and grain size evolution of a C-Mn steel during hot rolling was observed and validated with and without Nb addition. The pre-defined rolling schedule was predicted to exhibit incomplete recrystallization in the roughing phase due to the limited stored energy of deformation that resulted from low rolling loads and a higher number of rolling passes. The prior austenite grain size (PAGS) distribution was predicted and compared to the measured effective ferrite grain (FG) size distribution after the completion of hot rolling and phase transformation achieved using natural air plate cooling. Both the predicted PAG and measured FG distributions revealed the presence of multimodality, and both distributions were used for grain size reduction factor determination for γ → α transformation for the current study with 1.96 for 0 Nb and 1.70 for 240 Nb. The results presented in this paper are not only limited to the rolling schedule used in this paper because instabilities resulting in incomplete austenite conditioning are also observed when evaluating the cross-sections of other heavy plates and various steel grades utilizing different processing routes with comparable compositions such as modern lean abrasion-resistant steels, regular line pipe steels, and other similar grades.

Direct measurement of the resistance to ductile fracture propagation

The resistance to ductile fracture propagation remains a weak point in gas transmission pipelines’ safety since the emerging of this risk more than half a century ago. Full-scale burst tests of pressurized gas pipeline sections are performed to verify the ability of pipeline steel to arrest the crack propagation. However, motivated by the commitment to specific predictive models, the main outcome from full-scale burst tests (FSBT) has been in form of a binary “propagation/arrest” metric corresponding to each pipe in the test section. In the absence of a reliable laboratory-scale test demonstrating correlation with the full-scale resistance to ductile fracture propagation, such approach does not appear reasonable since it leaves line pipe manufacturers with very little clue regarding the preferential metallurgical designs. This work aims to better quantify the crack propagation resistance in FSBT providing metallurgists with a target property and facilitating the development of a new laboratory-scale mechanical test that shows reasonable correlation with FSBT. In order to improve FSBT testing methodologies, the pipe wall strain related to the crack propagation should be assessed along the entire test line. This can be implemented by means of modern 3D-measurement technologies that can digitize very large objects with high accuracy at a reasonably low cost. The method is demonstrated in the current work using the results of a recent FSBT carried out on X80 grade pipes. The results indicated that the plastic strain zone in FSBT can spread from the fracture surface over distances equivalent to tens of pipe wall thicknesses, while in the widely adopted drop weight tear test (DWTT) this spread hardly reaches one specimen thickness. Single-edge notched tensile (SENT) configuration provides much larger extent of the plastic zone into the specimen gauge when compared to DWTT whose major deformation mode is bending. Furthermore, the correlations between the strain parameters in different tests are discussed, and conclusions are drawn to promote a new laboratory test method for ductile fracture propagation resistance assessment in high strength steel pipe.

Influence of Physical and Chemical Stress on the Properties of CIPP Pipes Based on Vinyl Ester

Cured-in-place pipe (CIPP) is one of the trenchless sewer rehabilitation methods for repairing sewer pipe using different types of resin, curing technology and reinforced polymer fiber. In the research described in this article, the chemical and temperature resistance of CIPP pipes based on vinyl ester resin, cured with hot water, were tested. The specimens of the CIPP pipes were exposed to a chemically aggressive environment and an elevated temperature, namely 20% sulfuric acid (pH = 1) and a temperature of 50°C. The samples were tested every month for short-term flexural properties as well as hardness. Changes of the flexural properties and hardness were compared with reference samples that were stored under laboratory conditions (23±0,5°C, relative humidity 50% ±10%). It was found out that the applied aggressive environment does not have a negative impact on the mechanical properties of the CIPP pipes based on vinyl ester resin even after long-term exposure. Furthermore, the influence of the aggressive environment on the microstructure of CIPP samples was monitored by digital optical microscopy.

Study on the Combination of Pump Rod Pipe in Complex Structure

The 3-D mechanical model of the inclined shaft pumping pump and the optimization model of anti-partial wear structure and security position are established in this paper. Based on the real data of well, 148-inclined 2 slope measurement, the ordinary pipe rod combination, inclined well pumping pump lining oil pipe, and oil pump laser oil pipe are optimized and calculated. In order to improve the computing power and reduce computational time consumption, this paper uses cloud computing technology in the computing process. The results show that the combination method of the lining oil pipe and the ordinary continuous pumping rod has less axial force and lateral force, and finally, the combination method of different well pipes is obtained.

Improving the Heat Transfer using Fe3O4 Nanoparticles Suspended in Water Flow through Circular Tube

The new class of pressure drop and heat transfer enhancement through pipes and heat exchangers is defined a nano-fluid. The applications of this process are the cooling of oil inside heat exchanger and the flow of oil into the pipe line. In this work, the prediction of heat transfers and friction factor in a heated tube is studied. ANSYS software of CFD simulation through the geometrical problem undertaken was utilized. The Fe3O4 nanoparticles suspended in pure water has been adopted to flow through the test rig under ranges of nanoparticles mass concentrations and Reynolds number 1% to 4% and 4000 to 10000 respectively. The numerical results show that the friction factor and heat transfer enhancement increase as increase of nanoparticles mass concentrations 23% and 4% respectively. Additionally, the heat transfer is increased and the friction factor is decreased as increase of Reynolds number. It was concluded that Nusselt number increases due to add the solid nanoparticles to the water but slightly increases of pumping power. This obtained results are validated with the available data in the literature.

Early Estimation of Sewerage Line Costs with Regression Analysis

In Turkey, an average of 450 sewer line tenders are made annually and the total line length of these works is approximately 11000000 m. It is very important for both the investor and the contractor to know the costs of the sewer networks with such a large business volume. In this study, models are developed for early estimation of sewage line costs by the regression analysis method. Data belonging to 182 sewer line projects were used in the development of the models. Data on pipe diameter, line length, excavation depth, manhole amount, excavation amount, filling amount, filling type, shoring type, excavation class and real cost parameters were determined through the projects. Correlations between the determined parameters were specified and the parameters suitable for regression analysis were selected. As a result; among the developed estimation models, the equation using all selected parameters with a correlation coefficient of R² = 0.911 gave the most successful result.

Optimal Planning of Electric Vehicle Battery Centralized Charging Station Based on EV Load Forecasting

This article studies the planning of swapping electric vehicle (SEV) battery centralized charging station (BCCS) based on EV spatial-temporal load forecasting. First, according to the road topology of the planning area, the road topology model is built. The driving energy consumption process and endurance mileage model of EVs are developed. Then, we analyze the travel demand of people, the driving segments of SEVs (e.g., swapping private EVs and swapping taxis) are analyzed. Next, the spatial distribution model of SEVs is built. Thus, the spatial-temporal load model of SEVs is established. The sizing and locating planning model based on operation analysis is established for BCCSs. In addition, the photovoltaic (PV) configuration model in the urban grid is also established. Finally, considering the coupling relationship between urban distribution system and power line pipes, a grid planning method considering power line pipes is proposed. The planning model of BCCS aimed at minimizing annual comprehensive cost considering distribution system with PV is constructed. The MATLAB/YALMIP toolbox is applied to optimize the planning model in this article, and the feasibility and effectiveness of the proposed method are verified.

Buckling failure mechanism of liner pipe in bimetal mechanical clad pipe under complex loading

Bimetal mechanical clad pipe is one of the main measures for anti-corrosion control adopted in oil and gas fields. The liner pipe failure is a key problem that restricting the clad pipe applications. In this paper, a calculation model of clad pipe is established, and the buckling failure of liner pipe under complex loading was investigated. Effects of forming process, working pressure, external environmental loading and structural parameters on the failure mode of liner pipe were studied. The results show that increasing the residual contact pressure in the forming process is helpful to improve the buckling resistance of the liner pipe. The residual stress between liner and outer pipes can make the clad pipes bear a larger bending loads and have a larger critical curvature. Buckling mode “8” of the liner pipe occurs under complex loading. A larger working pressure can reduce the buckling degree and fold amplitude of the liner pipe. The liner pipe is more resistant to buckling in shallow water than in deep water. With the increasing of the wall thickness for liner and outer pipes, buckling resistance of the liner pipe becomes stronger. Finally, prediction formulas for critical curvature and the maximum normalized bending moment of the clad pipe are presented. The research results can provide a theoretical basis for the design, manufacture, and safety evaluation of clad pipe.

Theoretical investigation on the upheaval thermal buckling of a lined subsea pipeline

In this study, according to the nonlinear von-Kármán assumption and Euler-Bernoulli beam theory, a mathematical model is proposed to simulate upheaval buckling of lined subsea pipelines, which considers the difference in material properties of the liner and outer pipe. A closed-form solution is derived. The analytical solutions are verified by comparing them with the results in the literature. The influence of Young's modulus and the thermal expansion coefficient of the liner on the post-buckling response is analysed. The post-buckling behaviour of the outer pipe and liner are compared. The effect of the ratio of the liner's thickness to the outer pipe's thickness on the post-buckling response of the lined subsea pipeline is analysed in detail. The results show that the liner must be included in the analysis of upheaval thermal buckling. The post-buckling behaviour of both the liner and outer pipe are affected significantly by the thermal expansion coefficient of the liner. The displacement amplitude, axial compressive force, maximum bending moment and maximum stress all increase with increasing ratio of the liner's thickness to the outer pipe's thickness.

Survey of Welding Voltage from Welding Current and Arc Length in SMAW Process

The relationship between welding voltage, welding current and arc length was investigated in this study. Shielded metal arc welding (SMAW) process was used to weld API 5L X65 line pipes at welding current of 80 – 200A and arc length of 1.5 – 3.5mm. First and second order polynomial equation and Amson models were also used to study the welding voltage as a function of current and arc length. The results revealed that increase in current and arc length lead to corresponding increase in voltage. The welding voltage increased from 19.48 – 23.82V at constant arc length of 1.5mm and from 22.25 – 26.77V at 3.5mm arc length, as current increased from 80 – 200A. Voltage increase was more influenced by increase in arc length than increase in current. Welding currents between 140A and 180A and arc length between 2mm and 3mm are recommended for optimum quality welded joints. The analysis of the model performance showed that there was high correlation between the predicted and the measured welding voltage values (R2 up to 99%). However, the predictions from the second-order polynomial model slightly edged the Amson and the first-order polynomial models. Therefore, using either of these models could be helpful in making a decision on the range of welding input parameters that can be used to optimise welding quality and productivity in the SMAW process

Effects of the Alloy Design and Fabrication Process on Mechanical Properties of Mo + V-Added SA508 Gr.1A Steel for Main Steam Line Piping in Nuclear Power Plants

Effects of the Alloy Design and Fabrication Process on Mechanical Properties of Mo + V-Added SA508 Gr.1A Steel for Main Steam Line Piping in Nuclear Power Plants

Intercritical Austenite Formation and Decomposition in the Coarse Grain Heat-Affected Zone of an X80 Line Pipe Steel

Intercritical Austenite Formation and Decomposition in the Coarse Grain Heat-Affected Zone of an X80 Line Pipe Steel

State-of-the-Art Review on Application of Spray-Applied Pipe Linings in Gravity Stormwater Conveyance Conduits

State-of-the-Art Review on Application of Spray-Applied Pipe Linings in Gravity Stormwater Conveyance Conduits