Industrial Piping Systems Research Articles

Method of improvement of operational and technical conditions of a large cooling water system

Increasing the energy efficiency of industrial installations is one of the European Union’s priorities for achieving energy policy goals. These goals can be achieved, among others, by applying the appropriate methodology for modernization of cooling water distribution pipelines and improving their operation. Water distribution in cooling systems of large industrial installations is associated with significant hydraulic losses due to large flows and spatial spread of these systems. The losses are unavoidable and have a decisive impact on the energy consumption for pumping. Thanks to optimal design solutions, implementation of the repair program and proper operation of cooling water transmission pipelines, it is possible to significantly reduce hydraulic losses and water leakage. This will translate into reduced energy consumption for pumping and, as a result, improved energy efficiency. Abovementioned goals can be achieved by replacing or renovating pipelines. This paper deals with determination of a method and schedule of modernization of cooling water piping systems on the basis of a case study – a large industrial plant. Firstly, evaluation of the existing condition is carried out. Data on flow rate and cooling water pressure in the system are collected and analyzed. A graphical and numerical database of the cooling water system is made, which maps the system in terms of system geometry (lengths, pipe diameters, ordinates) and flow and pressure streams. The hydraulic losses of the cooling water system are simulated. The results of simulation calculations of pressure losses in water distribution system are presented in the form of maps of water pressure distribution in pipelines. Calculations for the pipeline network are performed in the current state for two hydraulic load cases: maximum and average. An assessment of the failure rate is made on the basis of information about the place, time, cause and type of damage. Wall thickness of pipelines in selected locations is measured and samples are taken from pipes in places of failure. The reasons for water pipeline failures are diagnosed. On the basis of pre-modernization simulation, information on failure rate and forecasts of future water demand are obtained, it is proposed which pipeline sections and in what order should be modernized. Depending on the technical condition, pipeline diameter and location in the field, pipe replacement or renovation is recommended. For pipes to be replaced, new diameters, adjusted to the forecasted demand are calculated. For pipes qualified for renovation, different site hardened liners or full wall pipes are recommended depending on pipe condition. Renovation methods, despite the reduction of the internal cross-section, provide similar or lower hydraulic resistance values. After selecting the variants of modernization of distribution pipelines, hydraulic simulations are carried out in the post-modernization condition, taking into account the future demand for cooling water. The presented method can be applied to cooling water systems as well as other industrial water piping systems.

Vortex dynamics during acoustic-mode transition in channel branches

The vortex dynamics during acoustic mode transition in channel branches were experimentally investigated with phase-locking particle image velocimetry (PIV) measurements. Particularly, a real-time waveform recognition approach, based on an offline pressure analysis by dynamic mode decomposition (DMD) and a real-time computation by field programmable gate array, was established. In the offline DMD analysis, energetic pressure DMD modes during acoustic mode transition were extracted from pressure data measured by a pressure transducer array and found to agree well with the natural acoustic standing-wave modes numerically determined from an acoustic modal analysis. The acoustic mode transition process was classified into three successive phases: Phase-I: hybrid acoustic modulations, Phase-II: no acoustic modulation, and Phase-III: third-order acoustic modulation. Subsequently, the vortex dynamics corresponding to Phase-I and Phase-III were determined by phase-locking PIV measurements with the real-time waveform recognition approach. The results are summarized as follows. (1) The vortex dynamics coupled with the first acoustic standing-wave mode in Phase-I were related to the first shear layer hydrodynamic mode in channel branches. (2) The vortex dynamics coupled with the second acoustic standing-wave mode in Phase-I were recognized as the signatures of the second shear layer hydrodynamic mode. (3) However, in Phase-III of the acoustic mode transition, modulated by the third acoustic standing-wave mode, the corresponding vortex dynamics fully developed into a second shear layer hydrodynamic mode. This work provides a better understanding of the complex vortex dynamics of channel flows with broad implications for industrial piping systems.

An FBG based smart clamp for the detection of incipient clamp looseness in industrial piping system

Distributed block clamps are widely used in hydraulic piping systems. However, due to wear and tear over time, the clamps may loosen, and if not detected in the early stages, it can lead to the catastrophic results. The common methods to detect the clamp looseness are based on the monitoring the pre-load of the connected bolts. The Fiber Bragg Grating (FBG) sensors, as the emerging sensing technology with anti-electromagnetic interference, small size and lightweight, easy to install, corrosion resistant, durable, cost effective and multiplexed properties has been used to design smart bolts and smart washers in the existed literatures recently. However, the distributed features of the smart bolts are limited to the through-hole structures and the smart washer can only be used to the bolted connections with big-diameter bolts, which makes the smart bolts and washers difficult to apply to distributed clamp bolted with small-diameter bolts. Therefore, an FBG based smart clamp is presented for the first time in this paper. The theoretical models, i.e. the analytical model and Finite Element Model (FEM) are developed to derive the measurement principle and optimize the structure of the clamp. The calibration experiments of the smart clamp are conducted to obtain the sensitivity of the smart clamp. Subsequently, a practical application, i.e. clamp looseness detection, is given in an industrial piping system which shows that the smart clamp is high sensitive to the incipient looseness of the clamp.

Robust metamodels for accurate quantitative estimation of turbulent flow in pipe bends

Pipe bends are inevitable in industrial piping systems, turbomachinery, heat exchangers, etc. Computational fluid dynamics (CFD), which is commonly employed to understand the flow behavior in such systems has very accurate estimation but is computationally cost intensive. Thus, in this paper, an efficient computational approach for such computationally expensive problems is presented. Using genetic programming (GP), metamodels are built using a small number of samples points from the CFD data. These GP metamodels are then shown to be able to replace the actual CFD models with considerable accuracy. The applicability and suitability of the GP metamodels are validated using a variety of statistical metrics on the training as well as independent test data. It is shown that the use of metamodels leads to significant savings in computational cost.

Multi-parameter dynamical measuring system using fibre Bragg grating sensors for industrial hydraulic piping

Due to the risk of failure induced by vibration fatigue, performance testing and condition monitoring are important to hydraulic piping systems in some critical industries such as nuclear power, oil and gas, and aerospace. A multi-parameter dynamical measuring system using Fibre Bragg Grating (FBG) sensors is proposed to detect multiple physical parameters (strain, temperature, pressure, acceleration, etc.) in industrial hydraulic piping. This paper investigates the multi-parameter measuring principle of FBG and presents the framework of the proposed system. Multi-parameter dynamical measuring experiments on a hydraulic piping test platform were carried out to validate the system. Multiple parameters of the hydraulic piping were obtained and analysed in the time, frequency and modal domains. The results obtained by FBG sensors are in good agreement with those detected by the reference electrical and piezoelectric sensors. The proposed system was implemented to monitor the clamping looseness of the pipe. Experimental results indicate that the proposed system could be used for multi-parameter dynamical measurements and real-time condition monitoring of complex industrial hydraulic piping systems in harsh environments.

Comparison of point cloud data and 3D CAD data for on-site dimensional inspection of industrial plant piping systems

Inspection is vital in industrial plant construction and management. However, traditional inspection methods that rely on human involvement and paper documentation are becoming untenable as modern industrial plants are becoming larger and more complex than legacy facilities. Hence, an efficient and robust method is required to support the inspection of modern industrial plants. In this paper, an improved technique relying on terrestrial laser scanning (TLS) for data acquisition and normal-based region growing and efficient random sample consensus (RANSAC) for point cloud data processing is proposed for the on-site dimensional inspection of the piping systems of an industrial plant. Consequently, the as-built condition of the plant is assessed via a distance-based deviation analysis and a comparison of geometric parameters between the as-designed and as-built models. The method is validated using a dataset acquired from a compartment of a ship has verified the robustness and reliability of the proposed approach.

Prediction for CUI in Piping Systems using Fuzzy Logic with Sensitivity Analysis of Corrosion Producing Factors

Corrosion under insulation (CUI) is a progressive problem for piping systems in oil and gas industries especially in petrochemical and chemical plants due to its catastrophic disasters and consequently its automatic impact on the environment. To ensure CUI problem should not spark sudden surprise in plants, indeterminate factors that contribute to the deterioration of pipes subject to CUI should be recognized and taken care seriously. Operating temperature, type of environment, insulation type, pipe complexity and insulation condition of the pipes are the key factors that cause significant deterioration of pipes due to CUI. As per its varying nature, CUI is difficult to predict as it remains hidden beneath the insulation and gets growth in an ambiguous and abrupt manner. For such an uncertain and critical situation, fuzzy logic is a good choice to be deal with. Thus, in this study, CUI corrosion rate for insulated carbon steel piping systems has been predicted by fuzzy logic using API 581 data. Predicted CUI corrosion rates obtained by the developed fuzzy logic model are committing quite satisfactory results when comparing with API 581 published CUI corrosion rates. At the end of study, sensitivity analysis (SA) of CUI producing factors has also been performed. SA is showing the role of each CUI producing factor in terms of percentage, having participation for the cause of 1 mm/year CUI in pipes. The predicted CUI corrosion rates and SA will help inspection engineers for setting and delivering the risk-based inspection priority for insulated piping systems at their concerned plants.

RETRACTED ARTICLE: Cluster and cloud computing framework for scientific metrology in flow control

Scientific metrology is one evergreen and Omni present field that has been continuously experiencing a great deal of research in developing new measurement benchmarks to cope up with the real time advancement in the current market. This has been greatly aided in recent times with the advent of intelligent computing networks and communication protocols through which there has been a great deal of migration towards cloud based services on a demand basis. The essential feature of cloud is the provision of quality service to the clients. The proposed research paper has taken the metrology of monitoring the flow rate in an industrial piping system towards a boiler as the case study and real time implementation achieved with the help of Labview and MyDAQ environment. The data from this DAQ is interpreted into the cloud network with subset reduction and regrouping based on features using a fuzzy c means clustering approach. The experimentation has been done for varying values of tuning constants in order to maintain constant flow and compared with existing research contributions. The results clearly indicate a fast computation time with low complexity overhead which is achieved with the help of cloud distribution.

Performance Criteria for Liquid Storage Tanks and Piping Systems Subjected to Seismic Loading

In this paper, performance criteria for the seismic design of industrial liquid storage tanks and piping systems are proposed, aimed at introducing those industrial components into a performance-based design (PBD) framework. Considering “loss of containment” as the ultimate damage state, the proposed limit states are quantified in terms of local quantities obtained from a simple and efficient earthquake analysis. Liquid storage tanks and the corresponding principal failure modes (elephant's foot buckling, roof damage, base plate failure, anchorage failure, and nozzle damage) are examined first. Subsequently, limit states for piping systems are presented in terms of local strain at specific piping components (elbows, Tees, and nozzles) against ultimate strain capacity (tensile and compressive) and low-cycle fatigue. Modeling issues for liquid storage tanks and piping systems are also discussed, compared successfully with available experimental data, and simple and efficient analysis tools are proposed, toward reliable estimates of local strain demand. Using the above reliable numerical models, the proposed damage states are examined in two case studies: (a) a liquid storage tank and (b) a piping system, both located in areas of high seismicity.

Similitude study of an in-service industrial piping system under high flow induced vibration

Flow induced vibration problem of an in-service duplex stainless steel piping system was investigated in previous research. The investigation required multiple sets of site measurement results at the offshore gas processing platform which raises the concerns of safety and its practicality. A lab scale of the mentioned piping system is preferable to study the flow induced vibration problem at different operating conditions to better understand the dynamic behaviour of this piping system. In addition, most of the dimensional analyses were performed either solely on structure or fluid system. System with flow induced vibration problem has never been attempted and thus it is important to perform similitude study of the piping system prior to fabrication of the lab scale model. Buckingham Pi theorem was applied and the similitude was verified by computational mechanics both qualitatively and quantitatively. The calculated non-dimensional variables of a scaled piping system in describing the flow characteristics which contribute to the structure deformation give similar scale factor, flow pattern and flow induced dynamic deformation and stress in this fluid-structure interacted piping system indicating that geometric, kinematic and dynamics similarity are achieved.

Simulation-based determination of systematic errors of flow meters due to uncertain inflow conditions

Computational fluid dynamics (CFD) provides well-established tools for the prediction of the velocity profiles in turbulent pipe flows. As far as industrial pipe and district heating systems are concerned, combinations of elbows are the most common pipe assemblies. Among the different pipe combinations, double elbows out-of-plane are of special interest, since they introduce strong disturbances into the flow profile and have a strong influence on many common types of flow meters. In front of a double elbow there is often another flow-disturbing installation. As a result the upstream conditions are unknown and an investigation of the resulting systematic bias on the measurement of the flow rate and the associated contribution to its measurement uncertainty is necessary. We demonstrate here that this can be achieved by a variation of the inlet profile in terms of swirls and asymmetry components. In particular, an ultrasonic and an electromagnetic flow meter are modeled in order to quantify the systematic errors stemming from uncertain inflow conditions. For this purpose, a generalized non-intrusive polynomial chaos method has been used in conjunction with a commercial CFD code. As the most influential parameters on the measured volume flow, the distance between the double elbow and the flow meter as well as the orientation of the flow meter are considered as random variables in the polynomial chaos approach. This approach allowed us to obtain accurate prediction of the systematic error for the ultrasonic and electromagnetic meter as functions of the distance to the double elbow. The resulting bias in the flow rate has been found to be in the range of 1.5–4.5% (0.1–0.5%) with a systematic uncertainty contribution of 2–2.4% (0.6–0.7%) for the ultrasonic (electromagnetic) flow meter if the distance to the double elbow is smaller than 40 pipe diameters. Moreover, it is demonstrated that placing the flow meters in a Venturi constriction leads to substantial decrease of the bias and the contribution to the measurement uncertainty stemming from the uncertain inflow condition.

Failure criterion for steel pipe elbows under cyclic loading

Abstract Steel elbow components are considered to be critical parts in industrial piping system due to their probability of collapse or failure. Therefore, the structural behavior of elbows is considered with respect to failure criteria through experiments and corresponding numerical models. Thirty-eight sets of experiments were conducted on three inch pipe elbow specimens. The numerical simulation results of the specimens are in good agreement with the test results. Damage indices available in the literature are used for failure estimation of the elbows. We suggest that the damage calculated using the Park and Ang damage index, and the Banon damage index, based on only one failed specimen under any constant amplitude cyclic loading, can be defined as the failure point and used to predict the failure of the component under other loading amplitudes. Therefore, the low cycle fatigue curve of an elbow can be derived using these simulation results. We also found that the calculated damage of an elbow component under constant, non-constant, and fully or partial amplitude reversals is quite similar.

Effect of Water Nutrient Pollution on Long-Term Corrosion of 90:10 Copper Nickel Alloy.

Due to their good corrosion resistance, copper and copper alloys such as 90:10 Cu-Ni are used extensively in high-quality marine and industrial piping systems and also in marine, urban, and industrial environments. Their corrosion loss and pitting behaviour tends to follow a bi-modal trend rather than the classic power law. Field data for 90:10 copper nickel immersed in natural seawater are used to explore the effect of water pollution and in particular the availability of critical nutrients for microbiologically induced corrosion. It is shown, qualitatively, that increased dissolved inorganic nitrogen increases corrosion predominantly in the second, long-term, mode of the model. Other, less pronounced, influences are salinity and dissolved oxygen concentration.

Investigation of Guided-Particle Transport for Noninvasive Healing of Damaged Piping Systems by Use of Electro-Magneto-Mechanical Methods

Summary Virtually all engineering applications involve the use of piping, conduits, and channels. In the petroleum industry, piping systems are extensively used in upstream and downstream processes. These piping systems often carry fluids that are corrosive, which leads to wear, cavitation, and cracking. The replacement of damaged piping systems can be quite expensive, both in terms of capital costs and in operational downtime. This motivates the present research on noninvasive healing of cracked piping systems. In this investigation, we propose to develop computational models for characterizing noninvasive repair strategies involving electromagnetically guided particles. The objective is to heal industrial-piping systems noninvasively, from the exterior of the system, during operation, resulting in no downtime and minimal relative cost. The particle accumulation at a target location is controlled by external electromagnetic/mechanical means. There are two primary effects that play a role for guiding the particles to the solid-fluid-interface/wall: mechanical shear caused by the fluid flow, and an electrical or magnetic force. In this work we develop and study a relationship that characterizes contributions of both, and ascertain how this relationship scales with characteristic physical parameters. Characteristic nondimensional parameters that describe system behavior are derived, and their role in design is illustrated. A detailed, fully 3D discrete-element-simulation framework is presented, and illustrated by use of a model problem of magnetically guided particles. The detailed particle behavior is considered to be regulated by three effects: the field strength, the mass-flow rate, and the wall interactions.

A novel hybrid testing approach for piping systems of industrial plants

The need for assessing dynamic response of typical industrial piping systems subjected to seismic loading motivated the authors to apply model reduction techniques to experimental dynamic substructuring. Initially, a better insight into the dynamic response of the emulated system was provided by means of the principal component analysis. The clear understanding of reduction basis requirements paved the way for the implementation of a number of model reduction techniques aimed at extending the applicability range of the hybrid testing technique beyond its traditional scope. Therefore, several hybrid simulations were performed on a typical full-scale industrial piping system endowed with a number of critical components, like elbows, Tee joints and bolted flange joints, ranging from operational to collapse limit states. Then, the favourable performance of the L-Stable Real-Time compatible time integrator and an effective delay compensation method were also checked throughout the testing campaign. Finally, several aspects of the piping performance were commented and conclusions drawn.

Large-eddy simulation in a mixing tee junction: High-order turbulent statistics analysis

This study analyses the mixing and thermal fluctuations induced in a mixing tee junction with circular cross-sections when cold water flowing in a pipe is joined by hot water from a branch pipe. This configuration is representative of industrial piping systems in which temperature fluctuations in the fluid may cause thermal fatigue damage on the walls. Implicit large-eddy simulations (LES) are performed for equal inflow rates corresponding to a bulk Reynolds number Re=39,080. Two different thermal boundary conditions are studied for the pipe walls; an insulating adiabatic boundary and a conducting steel wall boundary. The predicted flow structures show a satisfactory agreement with the literature. The velocity and thermal fields (including high-order statistics) are not affected by the heat transfer with the steel walls. However, predicted thermal fluctuations at the boundary are not the same between the flow and the solid, showing that solid thermal fluctuations cannot be predicted by the knowledge of the fluid thermal fluctuations alone. The analysis of high-order turbulent statistics provides a better understanding of the turbulence features. In particular, the budgets of the turbulent kinetic energy and temperature variance allows a comparative analysis of dissipation, production and transport terms. It is found that the turbulent transport term is an important term that acts to balance the production. We therefore use a priori tests to evaluate three different models for the triple correlation.

Performance-based earthquake evaluation of a full-scale petrochemical piping system

Assessment of seismic vulnerability of industrial petrochemical and oil & gas piping systems can be performed, beyond analytical tools, through experimental testing as well. Along this line, this paper describes an experimental test campaign carried out on a full-scale piping system in order to assess its seismic behaviour. In particular, a typical industrial piping system, containing several critical components, such as elbows, a bolted flange joint and a Tee joint, was tested under different levels of realistic earthquake loading. They corresponded to serviceability and ultimate limit states for support structures as suggested by modern performance-based earthquake engineering standards. The so called hybrid simulation techniques namely, pseudo-dynamic and real time testing with dynamic substructuring, were adopted to perform seismic tests. Experimental results displayed a favourable performance of the piping system and its components; they remained below their yielding, allowable stress and allowable strain limits without any leakage even at the Near Collapse Limit State condition for the support structure. Moreover, the favourable comparison between experimental and numerical results, proved the validity of the proposed hybrid techniques alternative to shaking table tests.

English

A biofilm is an assemblage of microbial cells which is irreversibly associated with a surface and enclosed in a matrix of primarily polysaccharide material. It may form on a wide variety of surfaces, including living tissues, medical devices, industrial or potable water system pipe or natural aquatic systems. A well-diversified organism such as algae, bacteria, protozoa, arthropods, etc. may be observed in the biofilm assemblage. The biofilm structure depends on the nature of substratum, hydrodynamics of system, nutrient availability, light and grazing capacity of organism. It has been observed that the introduction of substrata for the development of biofilm in the aquaculture system play a significant role. Biofilm organisms are microscopic and highly nutritious.  The organisms of biofilm may serve as single cell protein and are easily harvested by all size of cultured species in aquaculture as compared to planktonic organism in the water column. Biofilms are considered as good quality protein source (23-30%). Microalgae and heterotrophic bacteria are rich source of immune enhancers, growth promoters, bioactive compounds and dietary stimulants which can enhance growth performance of cultured organism. Substrata minimize the mortality by providing shelter and hiding places to cultured organisms. The attached nitrifying bacteria  contained in biofilm improve the water quality by lowering  ammonia waste from culture system through nitrification process. Biofilm based low cost technology will help resource poor farmers in generating protein rich nutrient in sustainable manner from aquaculture. An attempt has been made to review the role of biofilm in aquaculture.   Key words: Biofilm, fish growth, sustainable, water quality, survival, nutrient quality.

Unexpected trapping of particles at a T junction

A common element in physiological flow networks, as well as most domestic and industrial piping systems, is a T junction that splits the flow into two nearly symmetric streams. It is reasonable to assume that any particles suspended in a fluid that enters the bifurcation will leave it with the fluid. Here we report experimental evidence and a theoretical description of a trapping mechanism for low-density particles in steady and pulsatile flows through T-shaped junctions. This mechanism induces accumulation of particles, which can form stable chains, or give rise to significant growth of bubbles due to coalescence. In particular, low-density material dispersed in the continuous phase fluid interacts with a vortical flow that develops at the T junction. As a result suspended particles can enter the vortices and, for a wide range of common flow conditions, the particles do not leave the bifurcation. Via 3D numerical simulations and a model of the two-phase flow we predict the location of particle accumulation, which is in excellent agreement with experimental data. We identify experimentally, as well as confirm by numerical simulations and a simple force balance, that there is a wide parameter space in which this phenomenon occurs. The trapping effect is expected to be important for the design of particle separation and fractionation devices, as well as used for better understanding of system failures in piping networks relevant to industry and physiology.

Flow cells as quasi-ideal systems for biofouling simulation of industrial piping systems

Semi-circular flow cells are often used to simulate the formation of biofilms in industrial pipes with circular section because their planar surface allows easy sampling using coupons. Computational fluid dynamics was used to assess whether the flow in pipe systems can be emulated by the semi-circular flow cells that are used to study biofilm formation. The results show that this is the case for Reynolds numbers (Re) ranging from 10 to 1000 and 3500 to 10,000. A correspondence involving the friction factor was obtained in order to correlate any semi-circular flow cell to any circular pipe for Re between 10 and 100,000. The semi-circular flow cell was then used to assess experimentally the effect of Reynolds number (Re = 4350 and 6720) on planktonic cell concentration and biofilm formation using Escherichia coli JM109 (DE3). Lower planktonic cell concentrations and thicker biofilms (>1.2 mm) were obtained with the lower Re.