Internal Pipe Research Articles

Investigating reproducibility in multiphase flow metrology: Results from an intercomparison of laboratories

This paper presents the results of an intercomparison of multiphase flow laboratories. Conducted as part of EMPIR project 16ENG07 – MultiFlowMet II, the primary focus of the investigation was to determine the influence of laboratory-specific factors on the reproducibility of measurements made by multiphase flow metres (MPFMs). To minimise these effects as much as possible, a portable transfer package was designed, including the MPFM, a transparent viewing section, and a straight pipe section with a length of 100 internal pipe diameters. A reproducibility parameter, ζ, was developed to quantify both the reproducibility of the transfer package. Across the three laboratories, metrological compatibility was achieved for the majority of test points. By presenting the ζ values as functions of the gas volume fraction (GVF) and water liquid ratio (WLR), it was possible to identify flow regimes that may be more susceptible to reductions in reproducibility.

Analysis of Construction Quality Problems of Indoor Drainage Installation

If the indoor drainage pipe is blocked and the drainage is not smooth, sewage and pollutants will enter the room and endanger human health. If the pipeline is blocked as a result, a certain intensity of water pressure may be brought, which may cause pipeline leakage. In this article, we will analyze and explain the quality problems that often occur during the construction process due to the blockage of the internal drainage pipe, and propose appropriate methods and solutions to improve the quality of the project.

Study of diffusion bonded flat plate closed loop pulsating heat pipes with alternating porous media

This work aims to discuss the application of diffusion bonding process in the fabrication of flat plate pulsating heat pipes and to analyze the thermal performance effect of porous media structures applied to alternating channels in the evaporator section and compare it with a smooth conventional flat plate pulsating heat pipe. For that, two different copper flat plate pulsating heat pipes with five turns and 1.5 mm of inner diameter channels were fabricated, using diffusion bonding. Samples were made with two different diffusion process to evaluate the ability of the resulting device to keep the vacuum, avoiding the use of filler material during the welding process, which could result in contamination and, therefore, undesirable corrosion on both internal and external heat pipe surfaces. The results allowed to assess the quality of the bonded interface of two different configurations of the diffusion process. Microscopic results obtained on controllable pressure furnace and non-pressure control were analyzed, where the diffusion process with controlled pressure presented best results of continuity, alignment, and tightness. A comparison of the heat transfer characteristics between the two devices was performed under the same experimental conditions; for both devices, the thermal resistance in horizontal position showed to be like heat transfer of pure conductive copper plate. However, pulsating heat pipe containing smooth channels showed the lower thermal resistance in vertical position and filling ratio of 50%.

Study of deformation conditions at longitudinal pipes rolling from austenite steel grades

Stainless steels of austenite class 08–12Х18Н10Т have a high corrosion resistance, which stipulates for their wide application in various areas of industry. Technology of pipes production of the steels is rather specific and requires observation of some conditions. It was shown that temperature of a work-piece heating before deformation is an important parameter of the technology. It was noted that for the piercing of a steel work-piece with various chrome content, there is a rational temperature interval. Nonobservation of the temperature can lead to defects formation on internal pipe surface because of earlier destruction and opening of metal cavity during piercing. The choice of the rolling-out scheme has a direct effect on the work-piece forming in cross-sections. Results of hot rolling of Ø37×2,5 tube samples, manufactured of 08–12Х18Н10Т steel and carbon steel of grade 40 presented. The rolling was done at a laboratory mill. As a result of the experiment the lower limit of ovality of rolls grooves was specified for conditions of rolling of pipes from 08–12Х18Н10Т steels by 2-roll scheme. At the rolling with ovality B/H ≤1,07, defects appeared on the internal tube surface in the form of scratches caused by the mandrel. The rational range of ovality of grooves at multi-stand rolling can be from 1.08 to 1.15. According to criterion of groove overfilling by metal for steels 08–12Х18Н10Т, requirements were formed towards the groove width of the first stand of longitudinal rolling mill. The groove width must be larger than the sleeve diameter: for 3-roll scheme – at least by 2–3%, for 2-roll scheme – at least by 7.0–7.5%. Potential advantages of 3-roll scheme comparing with 2-roll scheme for rolling of 08–12Х18Н10Т steels were established as follows: lower probability of grooves overfilling by metal of the work-piece, absence of defects (scratches caused by mandrel), on the tube internal surface at minimal ovality level of 1.07, lower level of transverse pipe wall non-uniform thickness.

Mechanism and Procedure of Repeated Borehole Drilling Using Wall Protection and a Soft Structure to Prevent Rockburst: A Case Study

With the increasing mining depth of coal mines, the occurrence of rockburst, especially in mine roadways, is becoming critical as a severe dynamic disaster. This paper explores the stability control of deep mine roadways and solves the contradiction between the support and pressure relief of roadways by studying the use of an internal steel pipe for wall protection and a soft structure for energy absorption during repeated borehole drilling. Numerical simulations are performed to examine the effects of active support technology on the support structure during repeated drilling. Internal steel pipes can effectively prevent the support structure from being damaged. When the soft structure cracks, the energy transmitted from the rockburst to the roadway is significantly reduced. According to the deformation and failure characteristics of the surrounding rock of the 21170 roadway, the combination of anchor active support, hydraulic lifting shed support, and soft structure energy absorption is proposed. An engineering case study shows that the support method can effectively maintain the stability of the surrounding rock and ensure the safe mining of the working face. The proposed control method can provide reference for the prevention and control of rockburst in mine roadways under similar geological conditions.

Pipeline Inspection Tests Using a Biomimetic Robot.

This paper presents a biomimetic prototype of a mobile robot that can be used to inspect the subdrainage conditions of pipelines located along different highways in Mexico. Computer-aided design tools have been used to size each of the prototype components as inspired by anatomical spider structure. Springs are integrated to generate proper contact pressure against the pipe walls. The robot locomotion system is implemented with adaptable behaviour for the irregularities of pipelines along its journey. The robot prototype is manufactured in 3D printing with the advantage of having its spare parts easily replaceable. Reported results show internal pipe status through a mini video camera on the top of the robot.

Effects of high oil viscosity on oil‐gas downward flow in deviated pipes. Part 2: Holdup and pressure gradient

AbstractIn Part 1 of this work, new experimental data on high viscosity oil‐gas flow in inclined downward flow were presented. Flow patterns transitions were identified and analyzed, and the performance of some flow pattern prediction models was validated. This study uses the same experimental data set generated for a mixture of air‐oil (with a viscosity of 213 mPa · s) flowing in a 50.8 mm internal diameter pipe with inclination angles of −45°, −60°, −70°, −80°, −85° for a ranges 0.05 m/s‐0.7 m/s and 0.7 m/s‐7 m/s of superficial liquid and gas velocities, respectively, to investigate holdup and pressure gradient behaviour. The holdup and pressure recovery effects are explained in terms of the predominant transport mechanism through phase slippage and the mechanical energy balance. For a constant superficial liquid velocity, the average‐liquid holdup results show a discernible behaviour dependent on the relative velocity between phases (slip velocity). Consistently, results show a switch between the gravity or shear forces transport mechanism, that coincides with the switch of a sign of the total pressure gradient (pressure recovery effect). Performance analysis of the available mechanistic models has been presented. The results are not satisfactory, which justifies the need for a detailed study of the effects of viscosity and the inclination of the pipe in liquid‐gas mixtures.

An effective method of protection of oil field pipes inner surface

Corrosion is a key factor, effecting service life of field pipelines. A review of methods of protection of circle welding seam internal surfaces and adjacent end pipe areas presented in the paper, as well as their imperfections, a technology proposed to protect them by arc building-up corrosion-resistant coating. With the elaborated technology the pipe metal does not get considerable overheating, retaining correspondent level of mechanical properties. The properly selected parameters of building-up mode provide a minimal stirring in the process of building-up and the decrease of concentration of main alloying elements (Cr and Ni) in the protective layer does not exceed 20%. To determine the minimal length of protective layer, manual arc welding and welding in protective gases atmosphere by consumable electrode were considered as possible welding methods. Simulation in the program complex SYS-WELD enabled to determine the areas subjected to critical heating, what was confirmed by the data, obtained during imitation of a circle seam in laboratory conditions at 159×8 mm short pipe. The proposed technology excludes the porosity of the built-up layer and other defects, decreasing the efficiency of pipe metal protection. Content of alloying elements was selected, for the built-up coating to be inclined to passivation and to have high resistivity against corrosion processes. Total corrosion rate at the tests in an acid solution, having hydrogen sulfide, was less than 0.1 mm/year thanks to austenite structure. The efficiency of the proposed technology was confirmed by positive results of pilot-field tests at a by-pass line under conditions of Sutorminskoje oil, gas and condensate deposit.

Experimental and numerical investigation on convective heat transfer in actively heated bundle-pipe

The present work investigates heat transfer through natural convection using a series of experiments and computational modeling using Computational Fluid Dynamics (CFD) simulations in a one-meter bundle pipe with three internal pipes. The exact complex geometry is modeled where the flow channel is reduced through a spiral groove attached to a rod inside the internal tubes which was challenging compared to the flow in circular pipes in previous studies. To support the computational modeling investigations, convective heat transfer analysis is also studied through experiments with water as the production and heating fluids. Further, simulations are carried out with water-crude oil and aqueous ethylene glycol-water as the heating mediums and production fluids, respectively. Based on the heat transfer rates estimated from experimental data and CFD simulation results for the respective tubes, a modification to an existing Nusselt number is proposed for the range of temperature and flow rates used in the experiments. The proposed model, Nui = Pri m Rai n , was validated against experimental data and a good agreement with R2 values of more than 0.94 was achieved.

Parameters for Thermal Energy Systems Resilience

To provide a building design that is robust, adaptable, and affordable, one must understand the aspects of the building’s geographic location that will impact equipment selections, operating hours, and maintenance needs. One must also consider the building’s “thermal resilience,” i.e., its ability to withstand a heating plant outage. Designing for resilience is of growing importance, especially for military and government installations that must maintain critical functions even during outages. Buildings with a fast rate of temperature degradation with the loss of heating system function have low resiliency; buildings with a slower rate of temperature degradation have higher resiliency. In extreme cold climates, resiliency can play an integral role in protecting property during an outage. A drop in indoor temperature can pose a risk of freezing plumbing, which can lead to burst pipes and interior flooding that can cause enormous and costly damage, and which can effect a loss of workspace in an office building. More resilient designs must consider not only building HVAC installations, but also building envelope and the whole energy infrastructure, including thermal capacity of concrete and brick walls, internal water pipes, critical system redundancy, outside insulation without weak points, and a centrally controlled, low carbon hot water heat supply. This paper describes a quantitative approach to evaluate a system’s resiliency based on analytical and experimental studies conducted under IEA EBC Annex 73 and the Environmental Security Technology Certification Program (ESTCP) project Technologies Integration to Achieve Resilient, Low-Energy Military Installations, to evaluate building energy performance in extreme climate conditions. This work recommends that more thermally resilient designs for buildings in cold climates include consideration of increased thermal resistance of the building envelope, improved whole-building airtightness, and higher thermal mass.

Planning pipeline pigging operations with predictive maintenance

Deposition of waxes, asphaltenes, scales or hydrates is one of the most challenging operational problems in the oil and gas industry, both during production and transportation. Direct inspection procedures, such as employing a closed-circuit television system, allow visual assessment of the blockage, yet discretely in time and, consequently, of low value for the purpose of ensuring production over time. Therefore, an indirect predictive maintenance method for systematic evaluation of the internal pipe section is herein developed, adding a much needed solution to the current body of knowledge. Using continuous field measurements, it is now possible to predict when pigging should be performed to avoid significant blockages. Moreover, evaluating the maintenance plan risk is another major achievement. Finally, the proposed methodology and model were applied to a real case-study yielding good results compared to the current scheduled maintenance approaches.

Electrohydrodynamic‐enhanced internal pipe flows from a One‐Dimensional Turbulence perspective

AbstractThe One‐Dimensional Turbulence (ODT) model is applied for the evaluation of internal pipe flows subject to electrohydrodynamic (EHD) forces. The ODT formulation presented here incorporates the effects of the electrostatic potential energy transfer to the kinetic energy of the flow due to EHD instabilities in the presence of a corona discharge. Results for integral quantities such as the skin friction coefficient Cf and the Nusselt number Nu are obtained from ODT simulations and compared to available experimental data [1,2]. The results demonstrate the capabilities of ODT for simulating EHD flows.

Mortar Lining as a Protective Layer for Ductile Iron Pipes

The objective of the study is to recognise whether epoxy resin or polyurethane internal linings of ductile iron (DI) pipes create visibly smaller head loss in flow than cement mortar linings. Some data reported by the Ductile Iron Pipes Research Association (DIPRA) was used in the calculations. Only the data from hydraulic tests performed no later than 30 years after the placing of the mortar lining were considered. The average values of the Hazen–Williams roughness coefficients C for each of the internal pipe diameters were calculated, and single experimental data neglected. Two different approaches were taken for interpreting the DIPRA experimental results and omitting the fact that the flow rates during these tests are unknown. The Hazen–Williams roughness coefficients C were used in both for computing the friction factor f from the Moody chart for three values of flow rate: being equal to the optimal value for a given diameter, and then by 50% larger and 50% smaller than this value. Next, the computed friction factors were compared with the values predicted from the Moody chart for smooth pipes. In the first approach, the friction factors f were computed using the Epanet2 software, and in the second approach, a general equation for calculating f from known C and flow parameters was applied. Both approaches resulted in friction factors f very close to those for smooth pipes for the whole range of Q. In conclusion, more smooth plastic linings of DI pipes do not result in a significantly more visible saving of energy for pumping.

Mechanical characterization of composite pipe systems joined using different radii pipes subject to internal pressure

Failure tests for internal pressurized composite pipe system joined by using different radii pipes were carried out by the finite element method and experimental tests. The composite pipes were produced from E glass fiber/epoxy. DP410 and DP490 type adhesives were used to join the composite pipes. The numerical results and experimental results were compared. It was shown that the numerical analyzes results were close to experimental results. Tangential, radial, axial, and shear stress values on composite pipes and adhesive layers were obtained via numerical analyses in the radial direction. Additionally, the von Mises stress distributions were obtained on the adhesive. The effects of adhesive layer lengths, adhesives types, and orientation angle on the effect of the joint zone were investigated.

Application of Constrained Optimization Techniques in Optimal Shape Design of a Freezer to Dosing Line Splitter for Ice Cream Production

Design of multiple branches splitting of equal mass flow rate in complex rheological flows like ice cream near melting point temperature can be a challenging task. Pulsations in flow rate due to air pumping process and small fluctuations in temperature affecting flow rheology can determine a consistent difference in internal pipe velocity distribution, resulting in a significant difference in the distribution of ice cream dosage. Computational sciences and engineering techniques have allowed a major change in the way products and equipment can be engineered, as a computational model simulating physical processes can be more easily obtained, rather than making prototypes and performing multiple experiments. Among such techniques, optimal shape design (OSD) represents an interesting approach. In OSD, the essential element with respect to classical numerical simulations in fixed geometrical configurations relays on the introduction a certain amount of geometrical degrees of freedom as a part of the unknowns. This implies that the geometry is not completely defined, but part of it is allowed to move dynamically in order to minimize or maximize an objective function. From a mathematical point of view, OSD is a branch of differentiable optimization and more precisely the application of optimal control for distributed systems. OSD is still today numerically difficult to implement, because it relies on a computer intensive activity and moreover because the concept of “optimal” is a compromise between shapes that are good with respect to several criteria. In this work, the applications of a multivariate constrained optimization algorithm is proposed in the case of a mechanical ice cream 1 to 5 splitting system, required to distribute in an evenly way from one freezer into five dosing valves. Results allowed to design a retro-fitting system on an existing production plant reducing the dosing error down to 3% on the average.

On Investigation of Liquid Sloshing in Cylindrical Tanks With Single and Multiply Connected Domains Using Isogeometric Boundary Element Method

Abstract This paper explores an isogeometric boundary element method (IGA-BEM) for sloshing problems in cylindrical tanks with single and multiply connected domains. Instead of the Lagrange basis functions used in the standard BEM, the nonuniform rational B-splines (NURBS) basis functions are introduced to approximate the geometries of the problem boundaries and the unknown variables. Compared with the Lagrange basis functions, NURBS basis functions can accurately reconstruct the geometric boundary of analysis domain with almost no error, and all the data information for NURBS basis functions can be directly obtained from the computer-aided design (cad) or computer-aided engineering (cae) commercial software, which implies the modeling process of IGA-BEM is more simple than that of the standard BEM. NURBS makes it possible for the IGA-BEM to realize the seamless connection between cad and cae software with relative higher calculation accuracy than the standard BEM. Based on the weighted residual method as well as the divergence theorem, the IGA-BEM is developed for the single and multiply connected domains, whose boundaries are separately defined in the parameter space by different knot vectors. The natural sloshing frequencies of the liquid sloshing in a circular cylindrical tank with a coaxial or an off-center circular pipe, an elliptical cylindrical tank with an elliptical pipe, a circular cylindrical tank with multiple pipes are estimated with the introduced method by assuming an ideal (inviscid and incompressible) liquid, irrotational small-amplitude sloshing, and the linear free-surface condition. The comparison between the results obtained by the proposed method and those in the existing literatures shows very good agreements, which verifies the proposed model well. Meanwhile, the effects of radius ratio, liquid depth, number, and location of internal pipe (pipes) on the natural sloshing frequency and sloshing mode are analyzed carefully, and some conclusions are outlined finally.

Strain-based fatigue life analysis of pipelines with external defects under cyclic internal pressure

Gouge and dent are common mechanical defects in oil and gas pipelines. These defects with plastic strain cause stress concentration in the pipelines. Plastic strain is dependent on initial deformation and spring-back behavior of materials. Therefore, they reduce the fatigue life of pipelines. In this paper, the strain-base fatigue life analysis is investigated in pipelines with smooth dent or combination smooth dent and gouge defects under cyclic internal pressure. For this purpose, elastic-plastic multilinear isotropic hardening finite element simulation was used to investigate the effects of various factors, such as residual stress of dent, amplitude internal pressure, pipe geometry, gouge geometry, and smooth dent geometry on stress concentration factor (SCF). Finally, a new method is proposed for predicting the fatigue life of pipelines with uniform dent and uniform dent and gouge combination defects. The model is presented based on the Smith-Watson-Topper (SWT) criterion. A set of fatigue life test specimens with various pipe materials, size and geometry were prepared and tested. The specimens carried a smooth dent, as well as a combination of smooth dent and gouge defects, results of which were collected to validate those obtained based on the proposed model. The results of the predicted tests using the developed formula showed a good correlation to practical experiments.

Characteristics of horizontal gas-liquid two-phase flow measurement in a medium-sized pipe using gamma densitometry

Two-phase flows are common occurrences in many industrial applications. The understanding of their characteristics in industrial piping systems is vital for the efficient design, optimization, and operation of industrial processes. Most of the previous experimental studies involving the use of gamma densitometers for holdup measurements in air-water mixtures are limited to smaller diameter pipes (generally regarded as those with < 50 mm in nominal diameter). Further, very few literature report experimental data obtained using gamma desitometers. This paper presents an application of a gamma densitometer in the measurement of two-phase flow characteristics in an intermediate diameter pipe (nominal diameter between 50 mm and 100 mm). Scaled air-water experiments were performed in a 17-m long, 0.0764-m internal diameter horizontal pipe. Liquid superficial velocity ranged between 0.1–0.4 m/s while gas superficial velocity ranged from 0.3 to 10.0 m/s. The measured parameters include liquid holdup, pressure gradient, flow pattern, and slug flow features. The flow patterns observed were stratified, stratified-wavy, plug, slug, and annular flows. Plug and slug flow patterns showed good agreement with established flow pattern maps. Furthermore, the slug translational velocity was observed to increase with increasing mixture velocity, as reported by previous authors, hence establishing the reliability of the instrumentation employed. The slug body length was also measured using the gamma densitometer and was found to be within the range 24–36D with a mean length of 30.6D.

STUDY OF EFFICIENCY OF DRUM DRYERS OF METALLURGICAL PRODUCTIONS USING PERFORATED PIPES WITH LOCALIZATION OF HEAT FLOWS

The article presents the design of a drum furnace, providing for the provision of differentiated heat flows through the use of an internal perforated pipe. The design of the presented horizontal drum dryer with a perforated tube having openings is designed to eliminate such technological risk factors as the ignition of the oil component of the processed material, and the metal dispersed material itself having pyrophoric properties. As a result of the numerical simulation using the LS–DYNA program, the temperature and heat fluxes in the quasi-boiling zone of the drained oil-containing dispersed material were determined. The calculations made it possible to establish the dependence of the temperature in the quasi-boiling zone on the number of holes of the perforated pipe. Analysis of the obtained graphs allows us to conclude that the gradient of temperature (heat) flows in fixed sections of the furnace of the quasi-boiling zone.

Development and Sensitivity Analysis of an Empirical Equation for Calculating the Amplitude of Pressure Head Loss of Oscillating Water Flow in Different Types of Pipe

Low pressure oscillating water flow can reduce the investment and energy consumption of irrigation. It is also effective in reducing the clogging of an emitter and improving the spraying quality of sprinklers. In order to overcome the problem of the complex process in calculating the amplitude of the pressure head loss of oscillating water flow in different types of pipes, in this study, an empirical equation for the amplitude of the pressure head loss of oscillating water flow in different types of pipe has been developed. Further, validation experiments have been conducted to verify the accuracy of the calculated amplitudes of the pressure head loss by the empirical equation. The results show that average relative error between the measured and the calculated amplitudes of the pressure head loss by the empirical equation is 10.77%. Since the relative errors are small, it is an indication that the amplitudes of the pressure head loss calculated by the empirical equation are accurate. For the empirical equation developed in this study, the sensitivity of the model parameters has been analyzed. The results show that the amplitude of velocity, the internal pipe diameter, and the length of pipe are classified as highly sensitive. The average velocity, the period of oscillating water flow, and the modulus of elasticity of the pipe material are classified as sensitive. The thickness of the pipe wall is classified as medium sensitive. Compared with the calculation models of the existing researches, the empirical equation reduces the number of parameters required to be calculated, by which many complicated calculations are avoided, which greatly improves the computing efficiency. This is conducive to the efficient operation and management of oscillating water flow in irrigation pipe networks and also provides help for the optimal design of irrigation pipe networks.