Liquid Pipeline Systems Research Articles

Flow Improvers and Pipeline Internal Coating Benefits and Limitations with Respect to Pipeline Capacity Enhancement

This article illustrates the outcome of a theoretical examination of applying internal coating and flow improver to gas and liquid pipeline systems. A test case of a 12-inches, 18-inches, 24-inches, 30-inches, 36-inches, and 42-inches diameter gas and liquid transmission pipelines evaluates hypothetically, synergistic use of pipeline internal coating with flow improver to enhance flow rate of a pipeline and minimize internal friction. The improvements in pipeline hydraulics are recognized and the enhancement of pipeline capacity calculated over a broad range of parameters. The hydraulic benefits are presented as percentage increase in pipeline capacity using flow equations. Analysis shows that internal coating of pipelines plus injection of flow improver is hydraulically and economically viable for both gas and liquid pipelines with a typical capacity increase greater than 116%. Corrosion protection and safety is improved with low operating cost.

SYNERGETIC EFFECT OF A DRAG REDUCER AND PIPELINE INTERNAL COATING ON CAPACITY ENHANCEMENT IN OIL AND GAS PIPELINES: A LITERATURE REVIEW

This article presents a review of investigations on the effect of drag-reducing agents and internal coatings to increase gas and liquid pipeline system capacity, and the correlation between the pipe internal surface roughness, pressure drop, and the maximum flow rate of gas through the pipeline. The enhancements in pipeline hydraulics are identified and used to estimate increase in pipeline capacity and subsequent savings in operating cost over a wide range of fluid and pipeline parameters. The economic benefits are presented as payback periods using discount cash flow techniques. Moreover, the aim of this study was to review published information on drag reducers and pipeline internal coating relevant to pipeline capacity enhancement.

IoT based Optimal Liquid Metal Pipeline Damage Detection Using Hybrid Soft Computing Techniques

The pipeline plays an important role in transporting liquid metals over long distances. However, due to the harsh conditions on the construction site, the pipelines are always exposed to structural damage due to corrosion, damage, etc. These pipelines are often vulnerable to natural and third-party events such as explosions, earthquakes, explosions, drilling and vehicle traffic. Methods for monitoring liquid metal pipes include the use of continuous pipe assessments and pipe integration management systems. One of the biggest challenges faced by liquid metal pipeline system in the past has been the real-time monitoring of seamless pipes at certain locations. Previous studies of liquid metal pipeline monitoring have rarely focused on real-time wireless data transmission and data monitoring in the Internet of Things (IoT) operating system. In this paper, we propose an optimal liquid metal pipeline damage detection using IoT sensor platform and hybrid soft computing techniques. The proposed work consists of two fold systems such as data collection and data processing unit. In data collection unit, we utilize IoT sensors deployment with the multimedia sensors to gather liquid metal pipeline images which improve the detection accuracy. In data processing unit, we introduce a hybrid cat hunting based neural network (hybrid CHNN) to detect and localize the pipeline damages/cracks to avoid unwanted leakage and accidents. Finally, we evaluate the performance of our proposed hybrid CHNN detector with the different test samples and the simulation results are compared with the existing stateof- art pipeline damage detectors in terms of accuracy, precision, Recall and F-measure.

Transient Process of Pumped Storage System Coupling Gas–Liquid Interface: Novel Mathematical Model and Experimental Verification

The traditional calculation method for a transient process has high accuracy when the pipeline only contains liquid, but when the pipeline contains both gas and liquid the accuracy is greatly reduced. The coupling characteristics of gas–liquid interface movement in hydraulic transient processes are not clear due to the lack of high-precision mathematical model and experimental verification. This paper proposes a novel mathematical model of a gas–liquid pipeline system in a hydropower station based on Preissman’s implicit difference scheme and the method of characteristics. The solving mechanism of the transient process of gas–liquid movement was developed on the gas–liquid interface tracking method. Subsequently, the models proposed in this paper were applied in two typical scenarios of a gas–liquid transient process in a hydropower system, and their accuracy were verified in a field experiment. The comparison results showed that the novel model could accurately capture the movement of the gas–liquid interface, and the average relative error of the characteristic parameter was about 7.2%. Under the load rejection condition, the change speed of characteristic parameters was positively correlated with the pipeline slope. Under the pump failure after low-head startup condition, the maximum pumping discharge was negatively correlated with startup water level and the maximum reversal discharge and speed were positively correlated with the pump failure water level. Compared with the conventional method, the proposed model has advantages in solving the complex transient process coupling gas–liquid. It has potential value in applications such as the safe operation of hydropower stations, the transient process of water diversion projects and in urban pipe network operation.

Numerical Study on the Closing Characteristics of a Check Valve with Built-in Damping System

When check valve works in long distance or high lift liquid pipeline system, it is often subjected to water hammer. In this study, the UDF program was used to simulate the closing process of an axial flow check valve at the moment of pump shutdown, and the porous media model was applied to simulate the complete closing of the valve disc. It was found that there was local vacuum at the end of the valve disc at the moment when the valve was completely closed. The water hammer and characteristics of the force acting on the valve disc in the whole closing process were also obtained. In order to reduce the pressure surges on the valve disc and seat, a built-in critical damping was designed and added to the to the valve disc drive system. Since the spring force is directly proportional to the movement displacement of the valve disc, the elastic force and the speed of the valve disc reach the peak value when the valve is fully closed, while the damping force is directly proportional to the speed of the valve disc, therefore, the damping force increases gradually with the speed of the valve disc, which only produces the maximum damping force at the moment of fully closing, so as to reduce the slam shut, but has little effect on the closing time, thus adding damping is more effective than reducing the elastic force of spring. The current study provides a possible approach to protect the valve disc and seat of check valves in liquid supply and drainage systems.

Optimal economic operation of liquid petroleum products pipeline systems

AbstractThe majority of overland transport needs for crude petroleum and refined petroleum products are met using pipelines. Numerous studies have developed optimization methods for design of these systems in order to minimize construction costs while meeting capacity requirements. Here, we formulate problems to optimize the operations of existing single liquid commodity pipeline systems subject to physical flow and pump engineering constraints. The objectives are to maximize the economic value created for users of the system and to minimize operating costs. We present a general computational method for this class of continuous, non‐convex nonlinear programs, and examine the use of pump operating settings and flow allocations as decision variables. The approach is applied to compute optimal operating regimes and perform engineering economic sensitivity analyses for a case study of a crude oil pipeline developed using publicly available data.

Design and application of purified water preparation device for chemical analysis

Qualified purified water is essential for all chemical analysis. Spectral analysis, trace analysis and general chemical analysis require different purity of water. This paper introduces a kind of purified water preparation device which can be widely used in all chemical analysis work. The purified water preparation device consists of two-stage reverse osmosis device and water treatment device of ion exchange system. The two-stage reverse osmosis water treatment unit can be operated in two modes: program-controlled and manual mode, and the water production rate is about 80%. The ion exchange water treatment unit consists of two cation exchangers, two cation exchangers and one mixed ion exchanger, which can prepare silicon free water and sodium free water and meet the requirements of trace analysis. The ion exchange water treatment unit is equipped with independent purified water pipeline system and regenerated liquid pipeline system to avoid the pollution of purified water. The regeneration operation of ion exchange resin is simple, and the discontinuous water production can be easily realized. This set of purified water preparation device can adapt to various water sources to complete purification treatment, and produce purified water meeting various chemical analysis.

Historical analysis of U.S. onshore hazardous liquid pipeline accidents triggered by natural hazards

Incidents at U.S. onshore hazardous liquid pipeline systems were analyzed with an emphasis on natural hazards. Incidents triggered by natural hazards (natechs) were identified by keyword-based data mining and expert review supplemented by various data sources. The analysis covered about 7000 incidents in 1986–2012, 3800 of which were regarded as significant based on their consequences. 5.5% of all and 6.2% of the significant incidents were found to be natechs that resulted in a total hazardous substance release of 317,700 bbl. Although there is no trend in the long-term yearly occurrence of significant natechs, importance is found to be increasing due to the overall decreasing trend of the incidents. Meteorological hazards triggered 36% of the significant natechs, followed by geological and climatic hazards with 26% and 24%. While they occurred less frequently, hydrological hazards caused the highest amount of release which is about 102,000 bbl. The total economic cost of significant natechs was 597 million USD, corresponding to about 18% of all incident costs in the same period. More than 50% of this cost was due to meteorological hazards, mainly tropical cyclones. Natech vulnerabilities of the system parts vary notably with respect to natural hazard types. For some natural hazards damage is limited possibly due to implemented protection measures. The geographical distribution of the natechs indicated that they occurred more in some states, such as Texas, Oklahoma, and Louisiana. About 50% of the releases was to the ground, followed by water bodies with 28%. Significant consequences to human health were not observed although more than 20% of the incidents resulted in fires. In general, the study indicated that natural hazards are a non-negligible threat to the onshore hazardous liquid pipeline network in the U.S. It also highlighted problems such as underreporting of natural hazards as incident causes, data completeness, and explicit data limitations.

AEセンサを用いた液体流量計測法

Liquid pipeline systems are widely used in liquid transportation systems such as water-supply and drainage systems, water cooling systems, and oil pipeline systems. Liquid flow rate measurement in a pipeline system is very important for effective repair and maintenance, high-efficiency operation and pipeline safety. In this paper, a liquid flow rate measurement method suitable for a liquid pipeline is proposed, in which an acoustic emission (AE) sensor is applied to the surface of the pipeline. We constructed a flow rate measurement system consisting of an AE sensor and a signal processing circuit for transforming AE signals generated by the liquid pipeline flow into a corresponding flow rate. The characteristics of the flow rate measurement system were experimentally determined, using tap water as the liquid. The results demonstrate the possibility that a steady flow rate can be measured with a repeatability of approximately 7% over regions in which the flow rate ranges from 4.0l/min to 11.0l/min in a pipeline with a diameter of 13.3mm or 0.5l/min to 4.0l/min in a pipeline with a diameter of 6.2mm. The scope of application of the proposed measurement system is discussed.

Comparison of Performance of Two Run-of-River Plants during Transient Conditions

Water hammer is an unsteady hydraulic problem commonly found in closed conduits of hydropower plants, water distribution networks, and liquid pipeline systems. Because of either a malfunction of a system or inadequate operation conditions, a pipeline may collapse or burst erratically, resulting in substantial damages and human loss in some cases. Therefore, it is crucial that engineers design and/or analyze projects with reliable computing methods for all foreseeable operation situations. In this paper, transient flow situations in run-of-river plants are investigated for various operation conditions such as load rejection, load acceptance, and instant load rejection. A computer program using the method of characteristics is used in two case studies having Pelton and Francis turbines, respectively. On the basis of the field data of the plants, their computational models are set up, and resulting transient pressures are computed and compared with available measured pressures. Comparisons indicate that the mathematical model predicts the measured pressures closely for all simulations.

Leakage Detection of Pipeline System Based on Modeling and Identification

This paper presents a leakage detection method based on modeling the leakage in pipeline systems. For gas pipeline systems, a method based on the state space model is suggested. For liquid pipeline systems, an experiment based on the static model equation was performed. In the experiment, it was possible to detect the leak and to diagnosis the leak situation within the error of ±3%.

Effect of electrification in ball valves on ignition risk in liquid pipeline systems

Quantitative analysis of the electrostatic hazard in a liquid flow system requires a knowledge of the electrification at constrictions in pipelines to assess the possibility of incendive discharge from the plant and the liquid. Data on the electrostatic charge generated during the flow of toluene and toluene plus water through a ball valve are reported. Immiscible water concentrations greater than 0.1–0.2% (v/v) in toluene are found to markedly increase electrification and it is considered that the flow of the liquid through the valve, and not pipeline flow, is the major source of the high levels of electrostatic charge generated during the processing of two-phase systems. The conditions required for an incendive spark from an insulated component in the valve are described, and it is shown that these can be satisfied during the flow of toluene and toluene plus water. Only in exceptional plant situations could the presence of a valve increase the possibility of discharges from the liquid surface in a single phase system; however, the presence of free water produces charge densities on the liquid at which discharges from its surface may be possible.

THE HAZARDS OF BULK OXYGEN DELIVERY SYSTEMS

Many hospitals throughout the world obtain oxygen from a supply of bulk liquid oxygen which is delivered throughout the hospital via pipelines. An incident in which, through a series of malfunctions, dangerously high pressure developed in the hospital oxygen pipeline is described. The oxygen delivery system described lacked a relief valve to vent excessive pressures. In North America such a relief valve is required on all oxygen delivery systems. An alarm system is also required which detects rises in pipeline pressures. Regulations in the U.K. do not provide for pressure- relief valves on liquid oxygen pipeline systems. In the U.K. there is also no regulation on alarms to warn of high pipeline pressures. High-pressure accidents are a real threat to patients and hospital staff unless proper safeguards are built into oxygen delivery systems.