Flow Rate In Pipeline Research Articles

Study on the Operation Safety and Reliability of a Waxy Hot Oil Pipeline with Low Throughput Using the Probabilistic Method.

When the hot oil pipeline is running at a low throughput, it easily enters into an unstable condition, which seriously threatens the safety of the hot oil pipeline operation. In this study, the unsteady heat transfer and flow mathematical models for the hot oil pipeline system were established first by comprehensively considering the uncertainty of parameters during pipeline operation, such as the operating parameters (throughput and oil temperature), physical properties of crude oil (freezing point, viscosity, and thixotropic parameters), and environmental parameters (buried deep soil temperature and soil thermal conductivity). Then, the efficient Latin hypercube sampling (LHS) stochastic numerical algorithm was applied and further developed to quantitatively describe the operation safety of hot oil pipelines with low throughput in the form of probability. On the basis of the abovementioned research, the qualitative relationship between pipeline flowrate and friction loss is obtained. Finally, taking an actual crude oil pipeline as an example, the failure probabilities of the pipeline under different operating conditions were analyzed in detail. Combined with the target safety level of pipeline operation, the minimum allowable throughput of pipelines was determined. This study revealed the flow and heat transfer law of hot oil pipelines with low throughput and determined its operation safety and reliability under different operating conditions.

Nonintrusive Distributed Flow Rate Sensing System Based on Flow-Induced Vibrations Detection

Noninvasive real-time distributed pipeline monitoring technology is a key factor for the sustainable development of transportation pipelines. In this work, we have proposed and demonstrated a distributed microstructure optical fiber acoustic sensor (MOF-DAS)-based pipeline flow rate sensing system. Such proposed sensing system is based on the detection of flow-induced vibration (FIV) to achieve the flow rate measurement. We have used the Euler-Bernoulli beam theory to build up the FIV-based flow rate sensing model and numerically analyzed the pressures fluctuation at the wall under different flow rates. The simulation results showed that the standard deviation of pressure fluctuation is quadratically proportional to the flow rate. And we have experimentally verified and realized distributed flow rate detection in a pipe loop system built by a 25-m-long pipeline and a laboratory-made MOF-DAS system, which is the first time that the DAS is used for noninvasively pipeline flow rate detection. The experimental results are consistent with the simulated results very well. In the experiment, the flow rate range we measured was from 0 to 3.6 m/s, in which the measuring sensitivity of MOF-DAS at 3.6 m/s was around 0.03998 rad/(m·s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ). Furthermore, the uncertainty analysis of experimental results shows that the measuring uncertainty is decreasing as increasing of flow rate, which is around 13.75% at the flow rate of 0.8 m/s and reduces to less than 1% at the flow rate of 3.6 m/s. Compare with the results measured by the commercial accelerator, the MOF-DAS-based flow rate sensing system has a better and stable flow rate measuring results. Finally, the MOF-DAS-based distributed flow rate detection system has been successfully applied in the field test, which indicated huge engineering application potential, especially in long-distance pipeline networks.

Study of the Sediment Transport Law in a Reverse-Slope Section of a Pressurized Pipeline

This article reveals the change law of the head loss and critical deposition velocity during hydraulic transmission of a solid–liquid two-phase pipeline. This article also establishes a physical test model. A single variable is used to conduct the experimental research by changing the conditions of the pipeline flow rate, the sediment concentration, and the reverse slope degree. Based on an analysis of the test process, a new formula is proposed to determine the critical sedimentation rate of the pipeline that considers a change in the adverse slope. By analyzing the variation rule of the hydraulic slope of the pipeline sediment in different states and comparing the hydraulic slope of the horizontal pipeline and reverse pipeline in different states, different factors that influence head loss are revealed. Finally, the measured value of this test is compared with the Durand equation and the Worster equation. It was found that the measured value of this test was more similar to the Durand equation. This study not only provides theoretical support for sand removal in pipelines but also promotes sedimentation in reservoirs.

An integrated methodology for the supply reliability analysis of multi-product pipeline systems under pumps failure

As the main way for the long-distance transportation of refined products, multi-products pipelines are of vital importance to the regional energy security. The supply reliability evaluation of multi-product pipeline systems can improve the effective response to unexpected disruptions and guarantee the reliable oil supply. Based on reliability theory and pipeline scheduling method, an integrated supply reliability evaluation methodology for multi-product pipeline systems is proposed in this paper and the pumps failure, of which influence is the most complex, is focused on. In the methodology, the discrete-time Markov process is adopted to describe the stochastic failure and the Monte Carlo method is used to simulate the system states transition. With the pipeline flowrate upper limits under various pumps failure scenarios optimized in advance, the maximum supply capacity to the downstream markets in each trial is calculated by the pipeline scheduling model. Three indicators are also developed to analyze the pipeline supply reliability from the holistic and individual perspectives. At last, the methodology application is performed on a real-world multi-product pipeline system in China and the supply reliability is analyzed in detail according to the simulation results. It is proved to provide a practical method for the emergency response decision-making and loss prevention.

Gas Networks, Energy Storage and Renewable Power Generation

With an increase in variable and sometimes uncertain renewable generation coming on-line, there is an associated increase in the importance of energy storage to balance supply and demand. The gas network already stores and transports energy, and it has the potential to play a significant role for longer term energy storage. In addition, gas and electrical grids are becoming more integrated with fast responding gas-fired power stations, providing the main source of back up for renewable electricity in many systems. In 2017, Ireland’s renewable generation accounted for 19 % of electricity generated and was the second largest source of electricity generation after natural gas and coal with 51 % and 18 % respectively. The percentage of renewable electricity is rising and there is a 40 % target to be met by 2020. Using a simplified version of Ireland's gas network, with 14 nodes and 15 pipes, the objective of this paper is to investigate how hydrogen, generated through power-to-gas (P2G) from curtailed wind power, impacts the operation of the gas network system. A quasi-transient model was constructed in MATLAB to calculate the main characteristics of the gas network. The results show, with an increasing mass fraction of hydrogen in the gas network, that the pipeline flow rate needs to be increased to compensate for reduced energy quality due to the lower energy density of the blended gas. There is significant potential for the gas network to store and transport excess and/or otherwise non-transportable renewable electricity to maximize renewable energy utilization.

An integrated MILP method for gathering pipeline networks considering hydraulic characteristics

High investment highlights the importance of optimizing gathering pipeline networks. In view of the problem of ignoring hydraulic characteristics in previous studies, an integrated mixed-integer linear programming (MILP) model for gathering pipeline networks is developed in this study. Taking the minimum total construction cost as the objective function, the proposed model considers the economic and technical constraints such as obstacles, three-dimensional terrain, pipeline topological structures, pipe diameters, wellhead back pressure, and pressure equipment. The ant colony optimization algorithm is used for route optimization to provide parameters for the proposed model. Moreover, a piecewise method is employed to linearize the nonlinear hydraulic equations. Then, the model is solved by the CPLEX solver to obtain the optimal solution integrally, including the optimal connection topology, the location of the central processing facility, the position of pressure equipment, the diameter and detailed route of each pipeline, the pipeline flowrate and the node pressure. Finally, two real-world gas fields and a virtual oil field are taken as examples to demonstrate the feasibility and practicality of the model. The optimal results illustrate that this model can be implemented as a decision-support tool to optimize gathering pipeline networks in the actual design process.

A MILP model for the detailed scheduling of multiproduct pipelines with the hydraulic constraints rigorously considered

Multiproduct pipelines are the most effective and important way to transport refined products from refineries to the downstream market. The detailed scheduling of a multiproduct pipeline with the hydraulic constraints considered plays a vital role in the pipeline's safe and economic operation. Aiming at this issue, this paper proposes a continuous-time mixed-integer nonlinear programming (MINLP) model taking the sum of the pumps’ running and start/stop costs as the objective function. Based on a method proposed in a previous study for the rigorous description of the hydraulic loss changes in multiproduct pipelines, the pipeline hydraulic constraints and pump-related functions are considered directly and rigorously in the model. Other actual field processing constraints, such as the pipeline shutdown and contaminated oil flowrate, are also considered. To deal with the nonlinear relationship between the flowrate and pressure/volume, a piecewise linearization method is adopted, and the pipeline flowrate is graded according to the divided intervals. Finally, the application of the established model is successfully conducted on a real-world multiproduct pipeline through two case studies. A comparison with a previous discrete-time model is also performed to verify this model's applicability, accuracy, and superiority.

Towards high resolution monitoring of water flow velocity using flat flexible thin mm-sized resistance-typed sensor film (MRSF)

Novel flexible thin mm-sized resistance-typed sensor film (MRSF) fabricated using ink-jet printing technology (IPT) was developed in this study to monitor water flow rate in pipelines in real time in situ mode. The mechanism of MRSF is that the mm-sized interdigitated electrodes made by printing silver nanoparticles on an elastic polyimide film bend under different flow rates, leading to variation of the resistance of the sensor at different degrees of curvature. Continuous flow tests showed that MRSF possessed a high accuracy (0.2 m/s) and excellent sensitivity (0.1447/ms−1). A model of sensor resistance and flow velocity was established to unfold the correlation between the fundamentals of fluid mechanics and the mechanic flexibility of sensor materials. An analytical model yielded a high coefficient of determination (R2 > 0.93) for the relationship between the resistance increment of the MRSF and the square of the flow velocity at the velocity range of 0.25–2 m/s. Furthermore, a temperature-correction model was developed to quantify the effect of water temperature on the sensor resistance readings. MRSF exhibited a low temperature coefficient of resistance (TCR, 0.001) at the water temperature range of 20–60 °C. Computational fluid dynamics (CFD) simulations using the finite element method were conducted and confirmed both the underlying load assumptions and the deformation characteristics of the sensor film under various flow and material conditions. High-resolution monitoring of water flow rate using MRSF technology was expected to save at least 50% energy consumption for a given unit, especially under flow fluctuation. MRSF possesses a great potential to perform real-time in situ monitoring at high accuracy with ultralow cost, thus enabling the feedback control at high spatiotemporal resolution to reduce the overall energy consumption in water and wastewater systems.

Flow Control of Fluid in Pipelines Using PID Controller

In this paper, a PID controller is utilized in order to control the flow rate of the heavy oil in pipelines by controlling the vibration in a motor pump. A torsional actuator is placed on the motor pump in order to control the vibration on a motor and consequently controlling the flow rates in pipelines. The necessary conditions for the asymptotic stability of the proposed controller are validated by implementing the Lyapunov stability theorem. The theoretical concepts are validated utilizing numerical simulations and analysis, which proves the effectiveness of the PID controller in the control of flow rates in pipelines.

A hybrid time MILP model for the pump scheduling of multi-product pipelines based on the rigorous description of the pipeline hydraulic loss changes

As the primary means of transporting refined products, multi-product pipelines play a significant role in ensuring downstream energy supply. The pump scheduling optimization of multi-product pipeline can significantly lower the energy consumption of the pipeline. With the input parameters of pipeline flowrates and batch interface locations, which are determined by a specific detailed schedule, this paper first proposes an innovative method for a rigorous description of pipeline hydraulic loss changes during the multi-batch sequential transportation process. Based on the hybrid time representation, the scheduling horizon is divided into two levels of time windows and a mixed-integer linear programming (MILP) model for the pump scheduling of multi-product pipelines is established according to the proposed method. Various technical and operational constraints are considered. Finally, the established model is successfully applied to a real-world multi-product pipeline, with three operation modes, in China. The superiority, accuracy, and applicability of this model are validated in detail through comparison with a previous model.

Estimation of Flow Capacity in Pipelines Based on the Intrinsic Variation of the Volumetric Properties of the Natural Gas Mixture

In this paper, the Weymouth equation was applied so as to consider the pipeline characteristics, thermodynamic and physical gas properties. From literature, volumetric parameters like the specific gravity and compressibility are mostly assumed to be constants. Since they are related to flow, pressure and temperature values; neglecting their variation during pipeline transportation may lead to significant misleading results in the computation of pipeline resistance. Considering that providing global optimal solutions to instances of considerable size can become time-consuming, thus a mathematical optimization method was applied to find the solution that will satisfy these systems. Critical property correlations (Thomas, Standing and Sulton) and Compressibility correlations (Hall-Yarborough, Danchuk-Purvis Robinson are used mathematically to generate results that will optimize the gas pipeline transportation without assuming specific gravity and compressibility factor of the gas constant. The model proposed in this study showed that specific gravity and compressibility have an effect on gas pipeline flow rate. It was observed that at very low and very high specific gravity, that the gas flow rate is reduced by more than 10% while the gas density increases. It can also be stated from the results that, compressibility is directly proportional to flow rate and inversely proportional to density.

Optimization of flow rate measurement using piezoelectric accelerometers: Application in water industry

Abstract This paper presents a method for measuring flow rates in pipelines based on the flow induced vibration principle using water as fluid, eliminating the need for interrupting the flow and opening of the pipeline for installation of traditional water flow meters. Experimental measurements are carried out in an accredited laboratory for calibration of rate flow meters and a metrological validation, followed by an uncertainty evaluation, are presented. Data analysis is accompanied by a method of optimization that minimizes adjustment errors of measurement using regression by parts and by the selection of the optimum period to estimate more accurately the flow rate. The results meet the specifications of Brazilian Metrology Institute.

Research on Design and Construction Issues of Oxygen Pipeline in Chemical Plant

When the high-pressure chemical oxygen delivery device, the slightest mistake, likely to cause explosion, so the design oxygen pipeline, it is usually as a special danger medium piping design. This paper explores the design of the petrochemical industry in oxygen pipes, installation and construction unit issues and process piping installation and construction issues, systematic analysis of the piping in the design and construction should pay attention to the problems and solutions to ensure each petrochemical industry aspects of safe operation. Standard requirements and corresponding measures in aspects of oxygen pipeline flow rate control, material selection, pipe and valve selection and pipeline construction, which should be followed to ensure the safety of oxygen pipeline, which are described in details, according to the national standard/safety technical regulation for oxygen and relative gases produced with cryogenic method. Finally, the experience of safe use of oxygen pipelines is presented.

Indirect Method of Leakage Flow Rate Measurement in Compressed Air Pipelines

The paper deals with new indirect methods of leakage flow rate measurement in compressed air pipelines. In this method the measurement equipment has branch connection to the pipeline. The measurement method consists in determining the relation between air leakage flow rate in pipeline and the controlled air flow rate through adjustable throttle valve. Compressed air leakage flow rate in pipeline is calculated on the basis of pressure ratio measurements in two time intervals - during leakage without the controlled flow and with the controlled flow in branch line. The controlled air flow through the throttle valve is directly measured by flow meter.

The application of the Layer of Protection Analysis (LOPA) in Sour Water Refinery Process

Aims: The objective of this study was to analyze major accidents take place in sour water refineries, and to assess the adequacy of safeguard layers in the system. Also it has been provided safety recommendations in regarding to our analysis. Materials and Methods: Using the layer of protection analysis (LOPA), the role of protective layers in controlling the potential risks in Sour Water Recycling Unit is determined and required recommendations to reduce risk are provided. Results: This study showed that there are 49 high risk areas in Sour Water Recycling Unit. Moreover, Excessive flow rate in pipelines, Excessive temperature, Reverse flow, H 2 S leakage, Flow interruption, and Corrosion are the main identified hazards. Conclusion: It can be conclude that the effectiveness of protective layers is not enough and additional protective layers are required to improve the process safety system. Furthermore, LOPA is an improved technique when use the output of hazard and operability study (HAZOP) and it has some advantages due to its semi-quantitative nature in estimating hazards.

Achieving better accuracy of determining liquid flowrate in pipelines at a nuclear power station using flow metering orifices

A procedure for calculating the hydraulic characteristics of a flow metering orifice verified through a comparison with the results of calculations carried out according to the relevant Russian state standard is presented. The use of the proposed procedure makes it possible to obtain the required accuracy of liquid flow-rate measurements in the cases when the instrumentation unit fitted with a flow metering orifices does not fully meet the requirements of the standard.

Effects of Geometry on Aerodynamics of CFO

CFO(Critical Flow Orifice), micro sonic nozzle, is a device in tobacco industry to give a standard gas flow rate. Adopting the blocking effect of the convergent nozzles for compressible fluid, CFO can produce an accurate flow rate in pipe line. CFO can be used in micro flow calibration such as in the measurement of the pressure drop of filter rod or draw resistance of cigarette. To study the effect of convergent shapes on the aerodynamic characteristics of CFO, the 3D numerical simulations are carried out on two kinds of CFO structure shapes with finite volume method, based on the equations of compressible gas. The adopted turbulence model is the realizable k-ε model. According to the results of simulation, using Vyshinsky curve as the convergent curve is better than to apply the cone-shaped curve with the same exit diameter of nozzle. This is difficult to be observed in the experiments. The influence of convergent shapes can provide a basis for optimization design of CFO.

Estimating sonic gas flow rates in pipelines

This paper presents a detailed review and analysis of sonic gas flow in pipelines, adding considerably more detail to the analysis, particularly for long pipelines. Our results show that (1) the mass flow rate is asymptotic as the velocity head pipe loss increases (2) the asymptotic value is identical for both adiabatic and isothermal conditions and (3) a maximum is found in the gas flow, although this maximum is near the asymptotic value. A graphical method for isothermal flows and a simple, shortcut formula is presented using asymptotic analysis which accurately estimates gas flow rates in long pipelines under both adiabatic and isothermal conditions. Process safety applications are provided.

Leak detection in liquefied gas pipelines by artificial neural networks

AbstractA leak detection system for pipelines was developed by using artificial neural networks (ANN) for leak sizing and location and by processing the field data. This system can detect and locate leaks down to 1% of flow rates in pipelines carrying hazardous materials in about 100 s. A reference pipeline was considered for practical implementation of the package. The ability of the package to withstand spurious alarms in the event of operational transients was tested. The compressibility effect, due to “packing” of the liquid in the pipeline, causes many such spurious alarms. Adequate preprocessing of the data was performed by using a computer code in conjunction with the ANN to compensate for the operational variations and to prevent spurious alarms. The package detects leaks as small as 1% of the inlet flow rate and correctly predicts the leaking segment of pipeline with a probability of success that is greater than 50% for the smallest leak. In all cases, the timely response of the system was seen as a major advantage.

Unsteady Flow Measurement Using Pressure Change of Compressible Fluid. 1st Report, Examination of the Proposed Method.

Measurement of unsteady or pulsating flowrate in hydraulic pipelines is very important. In general, an air chamber is inserted to a pipeline as an accumulator in order to reduce the pulsation of flow. In this paper, we proposed a new method for the measurement of unsteady flowrate in a pipeline using the change in pneumatic pressure and temperature in the air chamber. In this method, it was assumed that the temperature was determined by change of state and heat transfer. Because the measurement of the chamber temperature is difficult, we estimate the temperature by numerically solving the heat transfer equation. In order to evaluate the method, a simple experimental model was employed, and measured flowrate profile was compared to the estimated one. Good agreement was achieved between the measured and estimated flowrates, and then the validity of this method was demonstrated.