Length Of Pipeline Research Articles

Signals denoising of leakage pressure in water supply pipelines using an improved wavelet filter algorithm

Abstract Accurate identification of leakage pressure signal is crucial for leakage detection and location of water supply pipelines. However, there is a lot of noise signals in the negative pressure waves generated during leakage accidents, making it difficult to identify leakage signals, and thus seriously affecting the accuracy of leakage detection. Therefore, in this study, we carried out leakage test of water transmission pipeline on our self-built test platform for transient flow with long-distance water transmission pipeline (pipeline length is 160 m, and diameter is 100 mm), and obtained the transient leakage pressure signals under various flow rates (15–55 m3/h). An improved wavelet filtering algorithm was proposed to filter the leakage pressure signal by optimizing the calculation of decomposition layers and the threshold processing strategy, and then compared with the traditional wavelet filtering method. The results show that the improved algorithm can denoise the leakage signals effectively, and the signal-to-noise ratio (SNR), mean square error (MSE) and mean absolute percentage error (MAPE) are all superior to those of the traditional wavelet algorithm. The results can provide support for leakage detection and location of water supply pipeline systems.

Optimizing large-scale CO2 pipeline networks using a geospatial splitting approach

CO2 transport infrastructure is the backbone of carbon capture and storage (CCS) technology for the mitigation of carbon emissions and project deployment viability. In conventional large-scale CO2 pipeline network designs, the storage sites are generally assumed as the centroids of the major geologic basins, however, this approach might provide suboptimal solutions since the large extension of some storage formations significantly increases the length of the CO2 transportation networks. To address this situation and obtain optimal pipeline routes, we present a novel geospatial splitting framework that partitions large basins into multiple sub-sinks. In our approach, we used a large number of reservoir models varying petrophysical properties and CO2 injection rates to compute pressure plumes through numerical simulations, leading to the calculation of the number of subregions for each basin as a function of the extension of pressure interference areas and boundaries. Finally, we applied K-means clustering and Voronoi polygon algorithms to partition large basins into subregions and obtain their sink coordinates. To demonstrate the capability of the developed workflow, we investigated two CO2 pipeline network modeling case studies using our splitting approach: one regional case study focusing on the Intermountain West (I-West) region and one nationwide case study covering the lower 48 states in the U.S. In both case studies, we compared the optimal pipeline routes using the original and new storage locations and examined the major differences. The use of the developed geospatial approach resulted in both cases in a shortening of the total pipeline network length by 13% and 10%, compared to the pipeline modeling with the original basins, leading to cost reductions of 25% and 17%, respectively, demonstrating that the location of point sinks has a critical impact on the length and expenses of pipelines to efficiently transport CO2 to distant storage sites. Therefore, the workflow presented here contributes to the proper and realistic modeling of case studies that support decision-making in CCS deployment.

Machine learning and numerical simulation research on specific energy consumption for gradated coarse particle two-phase flow in inclined pipes

In deep-sea mining engineering, accurately predicting the energy required per unit length of pipeline to transport a unit mass of solids (dimensionless specific energy consumption, DSEC) is crucial for ensuring energy conservation and efficiency in the project. Based on our previous work, we utilized the machine learning (ML) and the computational fluid dynamics (CFD)–discrete element method (DEM) method to study the transport characteristics and flow field variations of gradated coarse particles in inclined pipes (gradated particles refer to solid particles mixed in specific size and quantity ratios). First, we collect 1185 sets of data from 13 experimental literature, and after analyzing and processing them, an ensemble model based on four other ML models is developed. Both for pure substance particles (PS) and mixed particles (MP), the prediction accuracy of this ensemble model is relatively higher (PSs are spherical particles with uniform size and density, and MPs are particles with different shapes, sizes, and densities). Then, the CFD-DEM process and the operating conditions include low flow velocity with low volume concentration (2 m/s and 2.5%), low flow velocity with high volume concentration (2 m/s and 7.5%), and high flow velocity with low volume concentration (4 m/s and 2.5%). Under conditions of low flow velocity and low concentrations, as well as high flow velocity and low concentrations, the DSEC hardly changes with the variation of the pipe inclination angle. Under low flow velocity and high-concentration conditions, as the pipe gradually becomes vertical, the value of DSEC gradually increases.

Ice slurry pigging technology in drinking water distribution system: From flow mechanisms to pipelines cleaning application

Drinking water distribution systems are prone to (bio)fouling over time, negatively impacting drinking water quality. Ice slurry pigging is a promising technology used to remove solids attached to the inner parts of the pipe walls with ice-water mixture. To understand the ice slurry pigging flow characteristics and optimize its operations, this study presents the development of a Computational Fluid Dynamics model (CFD) combined with the Kinetic Theory of Granular Flow model (KTGF) and a thermal model. Firstly, the model is validated with experimental data from the literature on solid-liquid Two-Phase Flow (TPF), including flow characteristics and thermal effects. Secondly, simulations for a typical ice slurry pigging process show uneven ice phase fraction and shear stress distributions in the main pipe flow and vertical direction. Results indicate that the main limitations of effective pipe cleaning are due to buoyancy and thermal effects. Moreover, ice slurry with 1.0 mm ice particles performs better in providing effective shear stress compared to 0.1 mm, 0.5 mm, and 1.5 mm ice particles. Additionally, the optimal injection ratios of ice slurry with 1.0 mm are determined to be over 0.3 and 0.26 when cleaning pipeline lengths within 500 m and 1000 m, respectively.

Investigation of scaling-down experiments for accidental CO2 leakage dispersion risks in constant-pressure transportation pipelines within the CCUS process

Within the framework of strategies to prevent global warming, the safety of CO2 transportation pipelines requires thorough hazard analysis. Accidental leakage during long-distance CO2 transport, influenced by the size of the leakage opening, typically occurs under constant pressure conditions in the CCUS process. This paper introduces an innovative scaled experimental apparatus with an elliptical orifice, designed to simulate leakage due to free rupture in pipelines. The goal is to understand the risk characteristics of constant-pressure leakage in transportation pipelines. The results indicate that during leakage, the pressure drop in the source CO2 pipeline is less than 0.3013 MPa/s, which can be considered constant pressure leakage. The Mach disk size dm has a linear relationship with the elliptical leakage orifice ab. The scaled experiments also show that temperatures can drop to as low as −78°C, indicating significant low-temperature risks. This scaling experiment provides a new approach for predicting and mitigating diffusion risks in long-distance pipeline transportation by examining the relationship between pipeline length and orifice diameter. The research data and results contribute to a deeper understanding of the safety aspects of long-distance transportation of CO2 under constant pressure leakage conditions, providing a basis for risk assessment of leakage accidents and environmental protection measures.

Research on Predicting the Mechanical Characteristics of Deep-Sea Mining Transportation Pipelines

Deep-sea mining, as a critical direction for the future development of mineral resources, places significant importance on the mechanical characteristics of its transportation pipelines for the safety and efficiency of the entire mining system. This paper establishes a simulation model of the deep-sea mining system based on oceanic environmental loads and the mechanical theory of deep-sea mining transportation pipelines. Through a static analysis, the effective tension along the pipeline length, the maximum values of bending moment, and the minimum values of bending radius are determined as critical points for the dynamic analysis of pipeline mechanical characteristic monitoring. A dynamic simulation analysis of the pipeline’s mechanical characteristics was conducted, and simulation sensor data were obtained as inputs for the prediction model construction. A prediction model of pipeline mechanical characteristics based on the BP neural network was constructed, with the model’s prediction correlation coefficients all exceeding 0.95, enabling an accurate prediction of pipeline state parameters.

Evaluation of operational parameters for vessel's flexible subsea pipelines

AbstractThe operation of offshore vessels is directly related to the use of flexible pipelines. The article describes in detail the analysis of power, geometric, kinematic and technological parameters that affect the main operational characteristics of these pipes during their operation under water, in rough sea conditions and under wind loads. The article describes the degree of dependence between loads on the pipeline and velocity of the oncoming flow, the geometry of the pipe and the distance to the rigid surface of the ship's hull or the seabed. It was determined how the flow velocity during parametric oscillations of the pipeline in unrestricted flow and near the surface of the seabed affects the change in its drag and lift coefficients. An estimate of operational limits of flexible pipeline instability was obtained. On the base of changes in distributed load, specific values for safe lengths of pipelines were formulated. It has been stated that the probability of failure‐free operation of a flexible pipeline at a level of 0.99 is directly determined by the frequency of its oscillation. Its numerical values should always be at a level that does not exceed 3.7% of the frequency of pipe dynamic oscillations.

Potential assessment of CO2 source/sink and its matching research during CCS process of deep unworkable seam

It is of great significance for the engineering popularization of CO2-ECBM technology to evaluate the potential of CCUS source and sink and study the matching of pipeline network of deep unworkable seam. In this study, the deep unworkable seam was taken as the research object. Firstly, the evaluation method of CO2 storage potential in deep unworkable seam was discussed. Secondly, the CO2 storage potential was analyzed. Then, the matching research of CO2 source and sink was carried out, and the pipe network design was optimized. Finally, suggestions for the design of pipe network are put forward from the perspective of time and space scale. The results show that the average annual CO2 emissions of coal-fired power plants vary greatly, and the total emissions are 58.76 million tons. The CO2 storage potential in deep unworkable seam is huge with a total amount of 762 million tons, which can store CO2 for 12.97 years. During the 10-year period, the deep unworkable seam can store 587.6 million tons of CO2, and the cumulative length of pipeline is 251.61 km with requiring a cumulative capital of $ 4.26 × 1010. In the process of CO2 source-sink matching, the cumulative saving mileage of carbon sink is 98.75 km, and the cumulative saving cost is $ 25.669 billion with accounting for 39.25% and 60.26% of the total mileage and cost, respectively. Based on the three-step approach, the whole line of CO2 source and sink in Huainan coalfield can be completed by stages and regions, and all CO2 transportation and storage can be realized. CO2 pipelines include gas collection and distribution branch lines, intra-regional trunk lines, and interregional trunk lines. Based on the reasonable layout of CO2 pipelines, a variety of CCS applications can be simultaneously carried out, intra-regional and inter-regional CO2 transport network demonstrations can be built, and integrated business models of CO2 transport and storage can be simultaneously built on land and sea. The research results can provide reference for the evaluation of CO2 sequestration potential of China's coal bases, and lay a foundation for the deployment of CCUS clusters.

Seepage rate and uniformity of the stalk composite pipe for subsurface irrigation

AbstractAn orthogonal experiment with three factors and three levels was conducted to study the seepage rate and uniformity of stalk composite pipe (SCP) under subsurface SCP irrigation (SSI). Furthermore, to determine the best application mode for SSI, the pipeline length, irrigation volume and inner–outer diameter of the SCP were considered at a 0.4 m working pressure. The three levels corresponding to each factor were 20, 40 and 60 m; 30, 45 and 60 L m⁻¹; and 28–60, 40–80 and 50–100 mm, respectively. The results indicated that the seepage rate gradually decreased with increasing pipeline length. The pattern of the change in the seepage rate with irrigation volume was not obvious. There was a positive correlation between the seepage rate and the inner–outer diameter of the SCP. The irrigation uniformity coefficient, which was calculated based on the width of the surface wetting front, gradually decreased with increasing pipeline length. The impact patterns of irrigation volume and inner–outer diameter on irrigation uniformity were ambiguous. The seepage rate reached its maximum at the pipeline length, irrigation volume and inner–outer diameter, which were 20 m, 30 L m⁻¹ and 50–100 mm, respectively. There was the highest irrigation uniformity, with a pipeline length, irrigation volume and inner–outer diameter of the SCP of 20 m, 60 L m⁻¹ and 40–80 mm, respectively.

Design optimisation of a variable flow CO2 pipeline – A statistical approach

Pipeline transport has emerged as the most cost-effective method for transporting CO2 onshore. The CO2 flow rate is a key factor driving transport costs, underscoring the need to understand the impact of flow rate variability in CO2 pipeline networks on their design and economics. This paper presents an optimal pipeline design methodology for CO2 pipelines operating under variable flow that considers the probability distribution of CO2 flow rate and the pipeline length. The results imply that pipelines designed for optimal performance under variable flow rates often demand a higher level of overdesign compared to pipelines intended for steady-state conditions. Decision-makers must balance the trade-offs between pipeline oversizing and installing multiple pressure boosting stations, especially applicable to large transportation distances and projects of extended duration. The examination of different approaches to pipeline design reveals that a variable flow pipeline design based on mean flow rate is not recommended, because it is incapable of handling the maximum flow rate. This drawback is overcome by adopting the variable flow stochastic pipeline design presented in this paper.

Organization оf Electrochemical Protection оf Steel Underground Pipelines Against Corrosionin the Gas Distribution Industry of the Republic of Belarus

Steel underground gas pipelines occupy a significant share of the total length of gas distribution pipelines, and therefore their maintenance in proper condition is a constant and very urgent task. Due to its global nature, the main influencing factor affecting the technical condition of any steel underground pipelines, including gas pipelines, is corrosion, primarily soil corrosion. To protect against it on pipeline networks, along with insulating coatings, electrochemical protection (ECP) is applied, that is, following the definition of STO [Standard of Organization] 17330282.27.060.001–2008, protection of metal against corrosion in an electrolytic environment, carried out by establishing a protective potential on it or eliminating the anodic potential shift from the stationary potential. In the gas distribution industry of the country, methods and means of electrochemical protection have been applied since the beginning of gasification and the construction of the first gas pipelines. All gas supplying organizations of the State Production Association for Fuel and Gasification “Beltopgaz” (six regional and Minsk city), which operate gas distribution facilities, have specialized corrosion protection services. These services provide maintenance of available ECP equipment, conduct electrical measurements on gas pipelines and corrosion studies of soils, and have certified laboratories. This paper is devoted to the analysis of domestic experience in organizing electrochemical protection of steel underground gas distribution pipelines, searching for promising directions for its improvement and increasing efficiency through the implementation of a unified industry technical policy, automation and telemechanization of ECP equipment in the general context of digital transformation, optimization of the timing and volume of maintenance.

Assessing urban resilience based on production-living-ecological system using degree of coupling coordination: A case of Sichuan.

The issue of urban resilience plays great significance and value for the sustainable development of cities, which has attracted increasing attention from scholars and governments, especially in the western region of China. Based on the Production-Living-Ecological (PLE) system, this study attempts to describe urban resilience by the combination system that contains with P,L,E subsystem. The integrated approach including FAHP-EM,GRA-TOPSIS, CCDM, and ODM is proposed to reveal the urban resilience level and seek out the key constraints' indicators. Then, an empirical analysis of panel data of 18 cities in Sichuan Province from 2011 to 2021 was conducted to analyze the development process. The valuation results suggested that:(1)for urban resilience level, most cities at the moderate imbalance level and basically maintained at this level, only Chengdu is reaching the basic coordination level since in 2013.(2)The insufficient development of P,L,E subsystem is the reason for the moderate imbalance development, especially the key limiting factor is the P subsystem's low development level.(3)the most prominent obstacle indicators are x1(per capita local financial expenditure on science and technology), x2(per capita of R&D spending), x8(total export-import per capita), x14(number of people with basic medical insurance), x22(length of urban drainage pipeline), x23(number of public toilets per person) and the contribution values reach 7.56%,7.49%,11.02%, 9.14%,12.53%, 12.60% respectively. The detailed reference suggestions and effective measures put forwarded for policy makers and planners to promote urban resilience in Western China.

Sequential Transportation of Different Oil Batches through the Industrial Pipeline

In sequential pumping, several liquids with different physical and chemical properties are pumped through one pipeline. The advantages of this method include: using one pipeline to transport different liquids; more complete pipeline loading; and reduced cost of pumping. The paper considers the sequential pumping of two batches of oil blends with different physicochemical properties through an industrial oil pipeline. This is because a batch of high-paraffin oil blend is simultaneously pumped to an oil refinery, and a batch of high-viscosity oil blend is transported further along a pipeline. The difference between the thermal-physical and rheological properties of oil batches imposes a condition on the thermal mode of operation of an industrial pipeline. A mathematical model and algorithm have been created for calculating the sequential transportation of high-paraffin and high-viscosity oil blends. Thermohydraulic calculations of the model show the distribution of hydraulic head, pressure, and temperature of the batches under the operating conditions of pumping units and heating furnaces. The verification and validation of the theoretical analysis was carried out with experimental data measured by the SCADA along the industrial pipeline length. By the thermal mode of sequential pumping, optimal heating temperatures of oil blends were found at the industrial pipeline stations.

Safety of Tap Water in Terms of Changes in Physical, Chemical, and Biological Stability

Monitoring the quality of tap water in the distribution system and the ability to estimate the risk of losing its sanitary safety is an important aspect of managing the collective water supply system. During monitoring, the physical, chemical, and biological stability of water was assessed, which is the main determinant ensuring the appropriate quality of water for consumers. The physicochemical and microbiological quality of water was analyzed for two distribution systems (DSs), including the analysis of heavy metals (Zn, Fe, Mn, Cr, Ni, Cu, Cd, Pb). The tests carried out showed that in both distribution systems, the water supplied to consumers met the guidelines for water intended for human consumption. It can be considered that the risk of uncontrolled changes in water quality in DSs with an average water production of <10,000 m3/d and the length of water pipelines < 150 km is very low. The water introduced into the system differed in the place of water intake and water purification technology, which influenced the final water quality. In DS(II), higher values were recorded for hardness, conductivity, calcium, alkalinity, nitrates, and DOC. It was found that the content of heavy metals during water transport to the consumer increased in the case of DS(I) for Zn, Ni, Cu, Cd, and Pb, and in the case of DS(II) for Fe, Mn, Ni, Cu, Cd, and Pb. The observed differences resulted from the different quality of the intake water as well as from different materials used to build internal installations and their age and technical condition. The analyzed tap water was characterized by physical and chemical stability. However, the water did not meet the guidelines for water biostability due to the increased content of biogenic substances.

Small-scale district heating system as heat storage for decentralized solar thermal collectors during non-heating period

Solar thermal energy usage in the Baltic countries is currently low, so there is a need to find technically and economically feasible solutions to increase the appeal of this technology. Integration of solar energy into existing district heating systems is a way to increase the share of renewable energy sources while utilizing the existing infrastructure, thereby reducing capital investments, as well as mitigating the risk of solar collector overheating and eliminating the need for local storage tanks in buildings. This study presents a parametric study for evaluating the effectiveness of using a district heating system to store heat produced by decentralized solar thermal collectors and comparing the district solution to the traditional local solution. The TRNSYS 18 model was developed for this purpose. The model investigates the impact of different hot tap water demand profiles as well as pipeline diameters and lengths on system energy efficiency, showing a statistically significant difference (p < 0.05) between installing solar collectors on residential and restaurant or office roofs, and no significant difference (p = 0.24) between restaurant and office. The model shows that solar energy can be shared within a 500 m distance between neighborhoods and that a larger main pipeline diameter can increase overall system efficiency.

ГИДРАВЛИЧЕСКИЙ РАСЧЕТ ТРУБОПРОВОДА С РАССРЕДОТОЧЕННЫМ СБРОСОМ РАССОЛА В АКВАТОРИЮ

When producing water using desalination technologies, significant volumes of highly concentrated brines are formed. The solution of the problem of wastes recycling is an important global issue for water protection organizations, and the studies of the last decade confirm this. The article discusses an environmentally friendly method of dispersed uniform brine discharge into the water area, presents the developed technical solution and describes the principle of its operation. As an example, the authors calculate the hole diameters of the distribution pipeline for uniform brine discharge along the length. We calculated the radius and the scattering jet rate at a given distance from the hole in the distribution pipeline. The difference in brine salt concentrations at a depth of 20 m from the discharge point between the background concentration in the sea and the salt concentration was found to be from 0.439 % to 0.524 % along the length of the discharge pipeline. Dissolution of brines to safe concentrations becomes even more intense in the presence of sea currents. The research results can be used in the design and operation of such systems.

Design of Integrated System for Sediment Comprehensive Utilization in the Yellow River:Design of Sediment Pumping Device And Conveying System

Based on the goal of comprehensive utilization of sediment in the Yellow River, a complete sediment pumping and conveying system is designed. The main design research content: (1) Analyze the characteristics of the river basin in the middle and lower reaches of the Yellow River, determine the target working conditions according to the types, particle diameters, density and other parameters contained in the Yellow River, and determine the working capacity requirements of the entire sediment pumping and conveying system. (2) Provide the configuration scheme with the overall configuration plan, including the type, model, number of slurry pumps, the length of the slurry pipeline, the caliber of the pipeline and the driving equipment of the mud pump. (3) According to the determined target working conditions and designed working capacity requirements, calculate the flow rate and discharge pressure of the working environment, and then select the mud pump according to the flow rate and discharge pressure, and determine the rated rotational speed, rated power of the drive equipment and other parameters. (4) Complete the matching of the parameters of the mud pump and the slurry pipeline, and the matching of the driving equipment and the mud pump, so as to achieve the highest efficiency of the equipment operation under the conditions of the target working conditions.

Experiments and predictions for severe slugging of gas-liquid two-phase flows in a long-distance pipeline-riser system

Experiments concerning the flow regimes observed in gas-liquid two-phase flows in a long-distance pipeline-riser system were carried out and analyzed in this paper. The test loop with 0.075 m inner diameter consisted of a 314 m horizontal pipeline, followed by a 25 m downward-inclined pipe, and finally a 21.5 m riser pipe. An industrial-scale global flow regime map including 5 flow regimes was derived from differential pressure measurements in the riser and was used as a reference for improvements. Electrical capacitance volume tomography installed in the horizontal section was used to reconstruct the phase interface and calculate the average gas void fraction (GVF). An appropriate model for this system was selected by comparing the experimental GVF with different, widely used models. The occurrence of severe slugging flow (SS) can be predicted accurately using an improved model involving additional corrections that consider pipeline length, accurate GVF calculation, and gas density. This study supports the development of a suitable SS prediction model enabling safe design, operation, and control of practical systems.

A visualization study on characteristics of severe slugging in the S-shaped riser with a kilometer-scale pipeline

Severe slugging is a hazardous multiphase flow phenomenon in the process of offshore oil and gas transportation. Few visualization image data are obtained in experimental riser systems with kilometer-scale pipelines. Therefore, the interface distribution characteristics of severe slugging are visually investigated in a 29.1 m high S-shaped riser connecting a 1657 m long horizontal pipeline. Based on the image data of the gas–liquid interface structure and the pressure fluctuation of the riser, the flow pattern map is plotted. The high riser increases the accumulation space of severe slugging and prolongs the cycle period. A new prediction correlation of the slugging period suitable for experimental systems with different pipeline lengths is proposed. The long pipeline provides sufficient gas compression space and intensifies the blowouts of liquid slugs. The maximum velocity of the slug blowout in the riser reaches 23 times the gas–liquid mixed velocity. The gas expands sharply during the gas blowdown stage of severe slugging, which causes the instability of the gas–liquid interface in the horizontal pipeline and induces a large number of liquid slugs to flow into the riser; thus, the continuity blowdown of slugs appears in the riser.

Study on eliminating severe slugging by manual and automatic choking in long pipeline-riser system

Severe slugging produces huge fluctuations of pressure and flow rate, which is often eliminated by choking because of its easy operation and good performance. However, most published studies on choking are conducted in short-distance pipelines at atmospheric pressure, which is far from the oilfield conditions. In this paper, study on the influence of choking on severe slugging characteristics and control effect is carried out on the high-pressure long-distance pipeline-riser system. When using manual choking, the pressure fluctuation frequency increases and the system pressure exceeds its steady-state value under certain conditions. There is an optimal valve opening range when using automatic choking, which minimizes the fluctuation amplitude of differential pressure. The pressure required to eliminate severe slugging increases with the increase of pipeline length. In order to eliminate severe slugging automatically, a correlation for predicting the stable pressure at the riser bottom is proposed, with an average relative error of 10.9 %.