Emergency Shutdown Research Articles

Desain dan Pengujian Pengaplikasian Omron CP1L sebagai Remote Emergency Shutdown pada Aset Cementing

PT. X, an oil and gas service company in Indonesia, has a client facing safety risks at one of PT Y’s cementing assets. The client requested the implementation of an emergency shutdown component to mitigate the risk of accidents at the site. The primary challenge was the potential operational safety failures during cementing operations, which could lead to serious incidents without additional safety measures. This study aims to design and implement an emergency shutdown system based on the Omron CP1L to enhance operational safety at the cementing asset. The RES system was developed through a process of requirement identification, design, integration, and testing, supported by relevant literature studies. The system’s design includes the selection of appropriate hardware and software, as well as the development of logic to execute the shutdown when PT Y’s crew presses the emergency push button. Testing results indicate that the RES functions with an average delay time ranging from 1.5 to 1.9 seconds. The conclusion from this study is that the RES system is effective in enhancing operational safety and minimizing risks at PT Y’s cementing asset.

Mixed Convection Flow of a Viscous Dissipative and Heat Generating/Absorbing Fluid Through a Slit Microchannel

This paper is aimed at investigating the consequences of viscous dissipation and super-hydrophobicity on a magnetized mixed convection flow of an electrically conducting fluid across an up facing microchannel influenced by a transverse magnetic field. The plates were alternatively heated and incorporated with heat source/sink effect. The modeled governing equations have been obtained using a semi-analytical (regular perturbation) method. Various line graphs have been plotted to demonstrate the behavior of key parameter dictating the flow. It was found out that the thermal gradient and fluid velocity are significantly enhanced for mounting values of mixed convection Gre, Brickman number Br, Darcy porous number K and heat source S parameters in the superhydrophobic microchannel for constant pressure gradient Г. On the other hand, the velocity deteriorates for increasing levels of magnetic field M and heat sink S factors. Further, the comparison of this present analysis with previously published literature for limiting cases when Г=S=0 and Gre=1 showcased an excellent concurrence, thereby confirming the accuracy and validity of this present investigation. The findings from this research will find relevance in engineering, technological and industrial processes such as for solar collectors, nuclear reactors cooled during emergency shutdown, nuclear power plants, gas turbines and the various propulsion devices for aircraft, missiles, satellites and space vehicles.

Effectiveness of an Infection Control Program Among the Ysleta del Sur Pueblo in Preventing COVID-19-Related Hospitalizations and Deaths.

In response to the SARS-CoV-2 pandemic, the United States declared a state of emergency and implemented large-scale shutdowns and public health initiatives to prevent overwhelming public resources. The success of these prevention methods remains unresolved as restrictions and implementation varied from national, state, and local levels. Despite national and local regulations, individual adherence to preventative guidelines presented an additional layer of variability. Cases of COVID-19 continued to rise and fall over a two-year period on a national level, despite masking recommendations, ease of testing, and availability of vaccines. The Ysleta del Sur Pueblo is a Native American tribal community and sovereign nation located in El Paso, Texas. Speaking Rock Entertainment Center is a major business operated by the tribe, employing many tribal and non-tribal members from the El Paso area. Following nationwide re-openings of non-essential businesses, Speaking Rock implemented an infection control program with strict adherence to recommendations provided by the Center for Disease Control and Prevention (CDC) and additional disease control. This response would result in a fully vaccinated workforce within the wider community of El Paso, where the vaccination rate was less than 80%. Herein, we examine the efficacy of these measures and report on the success of the program resulting in zero hospitalizations or deaths compared with rates of 1 in 250 and 1 in 40, respectively, in the surrounding community.

Design and manufacture of an ultra-compact, 1.5 T class, controlled-contact resistance, REBCO, brain imaging MRI magnet

Abstract Brain imaging MRI comprises a significant proportion of MRI scans, but the requirement for including the shoulders in the magnet bore means there is not a significant size reduction in the magnet compared to whole-body magnets. Here we present a new design approach for brain imaging MRI magnets targeting ±20 kHz B 0 variation over the imaging volume rather than the more usual ±200 Hz making use of novel high-bandwidth MRI pulse sequences and distortion correction. Using this design approach, we designed and manufactured a 1.5 T class ReBCO cryogen-free magnet. The magnet is dome-like in form, completely excludes the shoulders and is <400 mm long. The magnet was wound using no-insulation style coils with a conductive epoxy encapsulant where the contact resistance of the coils was controlled so the emergency shut-down time of the magnet was less than 30 s. Despite acceptable coil testing results ahead of manufacture, during testing of the magnet, several of the epoxy coils showed signs of damage limiting stable performance to <55 A compared to the designed 160 A. These coils were replaced with insulated paraffin encapsulated coils. Subsequently the magnet was re-ramped and was stable at 81 A, generating 0.71 T as several other coils had sustained damage not visible in the first magnet iteration. The magnet has been passive shimmed to ±20 kHz B 0 variation over the imaging volume and integrated into an MRI scanner. The stability of the magnet has been evaluated and found to be acceptable for MRI.

Failure investigation of an AISI 316L pipe of the flare system in an off-shore oil platform

The oil and gas industries have severe operations conditions, which impose several failures in off-shore equipment. The Flare System is a pipe designed to safely dispose of relieving hydrocarbon gases and liquids during start-up, operational upsets, emergency shutdown, and maintenance activities. This work reported the failure investigation in a pipe of a high-pressure flare system. The pipe has a diameter of 220 mm and 4 mm of thickness, and according to the equipment datasheet, it was made in AISI 316L stainless steel. Two cracks were detected during the previous non-destructive inspection. Those failures were repaired, but another crack was detected after some months. Chemical composition was investigated using optical emission spectroscopy and elemental analysis, and the results are compatible with AISI 316L steel. The microstructure observed by light optical and scanning electron microscopes shows an austenitic matrix with deformation bands. The microhardness measurements and the XRD analysis show the martensite formation in those deformation bands. The tensile properties are in accordance with the standards. The fracture surface was investigated using scanning electron microscopy, the results point to fatigue failure.

Performance of a hydraulic buffer for PWR fuel assemblies: Mathematical modeling, numerical solutions, and experimental comparison

In a Pressurized Water Reactor (PWR), the hydraulic buffer serves as an essential component, significantly mitigating the impact force between the control rod drive mechanism and the fuel assembly in scenarios of emergency shutdown. This paper provides a complete analysis of the dynamical performance of a new type of hydraulic buffer, including its mathematical modeling, numerical solution scheme, and experimental comparison. During the fluid modeling, five typical cases are first classified in terms of both flow directions and coefficients based on the relative positions of the sleeve and the piston. A new flow iterative calculation format encompassing flow directions that can efficiently solve the flow coefficients is proposed during the fluid modeling. A one-way coupling scheme is used for the fluid–structure dynamical solutions. An experimental comparative study is conducted using the standard and reference (SR) case, and the present method shows good agreement with the experiment. In the present analysis: (1) The dynamic characteristics of the buffer are fully demonstrated using time history curves and phase diagrams, the physical parameters of fluid and structural motions, mainly including fluid pressure inside the chamber, dynamic relative displacement and velocity of the piston and sleeve, the rebound disparagement, and system kinetic energy; (2) Typical features of double peaks of the impact force, related to the collision between the piston, the impacted object, and the sleeve, have been captured and well simulated; (3) The variation of the two peaks of the impact forces with parameters and the transformation laws of the maximum impact force between these two peaks have been fully revealed.

Failure analysis in pyrolysis furnaces: Impact of carburization and thermal cycles on tube properties

The dominant failure mechanism in radiation coil tubes in pyrolysis furnaces is the detrimental interaction between carburization and reduced material ductility. This combination results in localized deformations, significant ovalization, and cracking in the tubes. At the same time, a second critical failure mechanism emerges during emergency furnace shutdowns, characterized by brittle fractures that can generate extensive longitudinal cracks in multiple tubes. This work presents a case study on the occurrence of failures that resulted in brittle fracture rupture of several tubes in a pyrolysis furnace that accumulated 43,720 h of operation. This highlights the practical importance of monitoring and managing the integrity of coil tubes. The tube samples were analyzed using optical and scanning electron microscopy, evaluation of carburization through magnetic permeability and NACE Test TM498, identification of carbides by X-ray diffraction (XRD), and dilatometry. Additionally, thermal stress analyses were performed using the finite element method, along with tensile tests at different temperatures. It was found that the tubes of the coil that operated at lower temperatures in their operational cycle did not rupture during the emergency shutdown, unlike other coils whose tubes experienced significant failures. An important contribution from this study is the demonstration of optimized operational cycle management and thermal control are essential in preserving protective oxide layers, minimizing coke formation and the effects of carburization and creep. This can reduce shutdown frequency and maintenance costs, improving the cost-effectiveness of the cracking process.

Flow prediction analysis of shutdown and restart for off-station pipeline based on flow assurance and energy-saving

Abstract Due to unforeseen operation errors or natural disasters, off-station pipelines may undergo emergency shutdown operations, necessitating a focus on flow assurance during the shutdown and restart process. Moreover, energy saving and emission reduction have become the focal points in the transformation of oilfield enterprises. This paper formulates a method for predicting the flow status during shutdown and restart of off-station pipelines based on the liquid conservation law, and the characteristic equations are solved by the characteristic line method. A comparative analysis is conducted on the operation rules of shutdown and restart for oil-water mixing transportation and dewatering processes under different water cuts. A typical off-station pipeline in a transfer station is selected as the case study object. The results indicate that due to the lower station heating required for the oil-water mixing transportation process, this process saves 44.3% of costs compared to the dewatering process. As the water cut increases, operation costs decrease and then increase, with the total cost of the 50% water cut scheme being the most economical. This study provides a reference for the safe operation and energy-saving management of off-station pipelines in the future.

SYSTEM OF MONITORING THE DEGREE OF DESTRUCTION FROM ELECTROCHEMICAL CORROSION OF UNDERGROUND METAL ELEMENTS OF OVERHEAD POWER LINE SUPPORTS

In this article, the studies were carried out and the block diagram was developed for a system of monitoring the degree of destruction from electrochemical corrosion of underground metal fastening elements for overhead power line supports. The analysis of the causes of emergency shutdowns of overhead power lines in the CIS and the methods of assessing the consequences used in foreign countries are carried out. The studies were aimed at modernizing the unified power system of Kazakhstan, reducing emergency situations and increasing reliability of power supply to consumers. The article presents a diagram of the design solutions of the proposed monitoring system for the portal-type support mounting unit. One of the aspects was direct controlling the degree of destruction of the support fastening points located underground. The proposed system allows collecting and transmitting to the control center the information of the degree of destruction from electrochemical corrosion of metal fastening elements of portal-type supports. Key words: portal type supports, overhead power lines, power system safety, power system reliability, galvanic corrosion, U-bolt, monitoring system.

Design and Development of an IoT-Based Leakage Detection System for Kitchens

In Nigeria, the frequent loss of lives and properties due to LPG usage for cooking necessitates urgent intervention. This paper presents an Internet of Things (IoT) based detection system to monitor LPG leakage in kitchens. Key components include a solenoid valve for gas flow control, an MQ6 sensor for LPG monitoring, and an STM32F411CEU6 microcontroller, programmed in embedded C, as the central processing unit of the system. The system introduces an emergency shutdown mechanism using an MMBT3904 NPN transistor. Upon detecting a leak, the MQ6 sensor informs the microcontroller, which prompts the user with a Short Message Service (SMS) and calls, and then triggers the transistor to close the solenoid valve if the leakage poses an explosion risk, thus preventing potential disasters. Additionally, a custom mobile app allows for remote monitoring and control of LPG leakage. To address Nigeria's unreliable electricity supply, the system includes a 5V power pack, a solar panel, and a battery for continuous power supply to the system. Deploying this system will significantly reduce the risks associated with LPG leaks in kitchens across Nigeria.

Метод обработки сигналов токов статора асинхронного двигателя для диагностики обрыва стержня ротора

The study is relevant due to high requirements to the reliability of the operation of auxiliary mechanisms of thermal power plants (TPP). The main source of mechanical power of auxiliary mechanisms of TPPs is high-voltage induction motor with squirrel cage rotor (IMSC). One of the most difficult causes of emergency shutdown to detect early is a broken rotor bar. The breakage of IMSC rotor bar is of latent character. It can be for a long time without considerable influence on the machine operation mode. Nevertheless, the fact of the breakage can be considered as an emergency condition of IMSC, and the consequences of leaving the groove of the magnetic core are irreversible. Scientifically, early diagnostics of IMSC rotor bars breakage of TPP auxiliary needs is both a difficult and extremely urgent task. The existing methods of diagnostics of such damage are based on measurement and analysis of vibration and acoustic physical quantities. The most common electrical parameter, used as a source of information, as a rule, is current consumption. And most of methods are based on Fourier analysis. The purpose of the study is to develop a mathematical algorithm to process digitized curves of stator phase currents to diagnose high-voltage IMSC. The theory of electric machines, the method of analytical approximation of experimental data, the method of regression analysis have been used to solve the problem. Experimental data is obtained, and testing of the algorithm is conducted on an experimental installation with a 0,4 kV induction motor with a modified design of the active part of the rotor developed for physical simulation of IMSC broken rotor bar. This paper proposes a new method of digital processing of stator current signals based on the regression analysis method for diagnostics of IMSC rotor winding. The authors have developed an algorithm for mathematical processing of digitized stator current curves based on regression analysis in the cosine-sine basis to identify the diagnostic sign of failure of one rotor bar of IMSC rotor. The authors have determined the number of harmonic components that best describe the initial signal from the point of view of the balance between saving computational resources and accuracy of approximation. A mathematical algorithm to detect the rotor bar breakage of an induction motor based on regression analysis of stator currents has been obtained and tested. It allows to detect rotor circuit damage with 97 % accuracy. At the same time the diagnostic sign changes its level when one bar breaks by 5 %. It is recommended to adapt the algorithm to the programming languages of microprocessor relay protection units.

Impact of adding high-concentration neutron poisons to reactor moderator system for guaranteed shutdown

To ensure a reliable shutdown of the proposed advanced heavy water reactor (AHWR) of Indian origin during emergency conditions, it is imperative to use an increased concentration of liquid neutron poison for injection into the moderator system due to its higher reactivity. The sudden injection of this liquid poison may cause a surge in radiolytic product (H2O2 and H2) yield, posing safety risks. If H2/D2 yield exceeds 4 % (v/v), a combustible mixture with oxygen can be formed and presence of oxidizing H2O2 can enhance corrosion. Hence, accurate estimation of H2O2 and H2 is imperative from the reactor safety point of view. We investigated gadolinium and boron (two liquid neutron poisons) at varying concentrations through high energy electron beam and gamma radiolysis. The radiolytic yields from both the liquid neutron poisons of equivalent concentrations at a constant dose and operating moderator conditions in electron beam and gamma radiolysis were compared. The molecular product yield was observed to be concentration and dose-rate-dependent for both the neutron poisons. Electron radiolysis exhibited a higher yield of H2O2, whereas gamma radiolysis resulted in a greater H2 yield. In electron radiolysis, the H2O2 yield decreased with increasing B concentration. These results give an overall estimation of radiolytic products for a particular dose rate, total dose and effect of head space volume over liquid irradiation zone from these two liquid poisons of a particular concentration. These insights will aid in selecting suitable poisons and managing their effects effectively to avoid hydrogen deflagrations after emergency shutdown.

(Invited) Stack Test Facility for PEM Water Electrolysis up to 400 Kilowatt and Lessons Learned at Stack Scale-up

A new type of energy system based on renewable energy sources and hydrogen technologies is put into operation at Forschungszentrum Jülich, Germany. The aim of the "Living Lab Energy Campus (LLEC)" project is testing and optimizing the systems interactions. Central components are wind power and PV systems, PEM electrolysis system, conditioning and subsequent gas transport in H2 and O2 pipelines, H2 storage in LOHC reactors and hydrogen use in combined heat and power plants.The PEM electrolysis system in Fig. 1, left, is an R&D test platform which was jointly configured by Forschungszentrum Jülich (IEK-14) and Greenlight Innovation Corp. and built by Greenlight. It offers a range of different operating modes and system configurations that will be studied embedded into the LLEC: Equal pressure or differential pressure anode/cathode up to 50 bar(g).Water circulation on anode and/or cathode side.Stack cabin with flexible connections for fluid inlets and outlets as well as electrical current. This makes it easy to connect and operate different stacks (also from other manufacturers).Automated system operation, simulation of load profiles (e.g. wind/PV). The system is CE-certified and can run continuously under automatic control. Critical system conditions, such as exceeding the H2 concentration limit (currently set at 30 % LEL) in the O2 gas flow, immediately initiate an emergency shutdown program. In the emergency shutdown program, the power supply unit is first switched off and the pressure on the anode and cathode side is reduced to ambient pressure. The reason for the fault leading to the shutdown is stored in the system control unit and can be called up. In addition, all measured values and states of the installed sensors and actuators are recorded by the system control unit and stored with an adjustable time resolution. The measured values can be used to monitor the system behavior and detect problems at an early stage, but also to characterize and balance the overall system, system components and the stack.For generating large amounts of hydrogen within the LLEC project, IEK-14 initiated the development of a PEM electrolysis stack. The electric design data was taken from the performance data of a laboratory cell (1.75 V at 3 A cm-2, 20 cm² active area) and scaled up. The stack consists of 60 cells with an active cell area of 1056 cm².The bipolar plate was completely redeveloped. The main features are: Use of porous layer structures with different degrees of fineness as a flowfield structure.Welding of all components of the bipolar plate to form a material-locking unit. Preliminary tests in short stacks with bipolar plates on a smaller scale (100 cm² active cell area) showed promising results. The design and manufacturing process for the bipolar plates have now been patented (EP4128399) and published (Janßen H et al., A facile and economical approach to fabricate a single-piece bipolar plate for PEM electrolyzers, Int. J. of Hydrogen Energy, 2023).An interesting aspect that will be discussed further in the presentation is the scale-up of both the active cell area and the number of cells. Ultimately, the aim is to understand which parameters (and their fluctuations) are mainly influencing the stack performance during scale-up. A data analysis of component properties and a comparison with operating data should provide initial indications. Fig. 1, right, shows a 60-cell PEM stack with an active cell area of 1056 cm², of which short stacks with 4 cells were also constructed. Figure 1

Early detection of combustion instabilities in liquid rocket engines: Assessment of statistical, recurrence, and fractal analyses for sub- and supercritical pressure conditions

Safe shutdown of a liquid rocket engine in ground testing prior to the onset of damaging combustion instabilities through reliable detection of instability precursors would translate to time and cost savings in engine development programmes. Methods derived from statistical, recurrence, and fractal analysis have been successfully applied in the literature to detect precursors in unsteady pressure signals from canonical combustion experiments, gas-turbine combustion experiments, and sub-scale rocket combustion experiments operated at low pressures. In the present work, several such methods were applied to data from two cryogenic oxygen-natural gas rocket experiments operated at higher pressures than previously reported; both sub- and supercritical with respect to oxygen. The goal was to identify methods that can discern limit-cycle instabilities from intermittently unstable operation and are sufficiently responsive to be applied as emergency shut-down criteria in engine tests. Among the methods applied were the standard deviation, variance of the auto-correlation, the second spectral moment, the ratio between determinism and recurrence rate, the Hurst-exponent, and the multifractal range. The second spectral moment, the Hurst-exponent, and a measure derived from the multifractal spectrum all have short detection delays for instability onset and short-lived could be discerned from self-sustaining instabilities with an appropriate choice of threshold value. They also have moderate computation cost which makes them of interest for potential real-time implementation. The Hurst-exponent has the additional advantage of a common threshold value for all test cases addressed, demonstrating its potential for broader application independent of combustion device or operating conditions.

Seismic response of jacket-supported offshore wind turbines for different operational modes considering earthquake directionality

This study aims to analyse how jacket-supported OWTs functioning in three different operational modes (power production, emergency shutdown and parked mode) respond to seismic actions when subject to different incoming wind directions and ground motion shaking directions. To do so, the seismic response of the NREL 5MW OWT founded on the OC4 jacket substructure is simulated using an OpenFAST model that includes multi-support seismic input, soil–structure interaction and kinematic interaction. The impact of the working conditions and of the directionality of the loads on the jacket substructure is analysed and discussed. The tower top accelerations and displacements are examined for different sets of cases, and the seismic response of the jacket is studied in terms of internal forces and von Mises stresses along the different levels of the substructure. The results show, and quantify, the relevance of considering the different operational modes for a correct design of the substructure and of the foundation. The maximum structural stresses within the jacket substructure appear almost always in power production, with the exception of the top part of the legs, where higher stresses arise during emergency shutdown in several cases.

Investigation of the indoor air temperature in a civilian building after an emergency shutdown of the heating system

Investigation of the indoor air temperature in a civilian building after an emergency shutdown of the heating system

Reservation of the heat supply system with biofuel heat energy sources

The implementation of the reservation of the heat supply system to a populated area was analyzed. It is noted that increasing the reliability of heat supply to consumers is a fundamental task, especially given the current military situation in Ukraine. The solution to this difficulty is considered when reserving heat supply by constructing a backup source of thermal energy using alternative types of fuel. A combined thermal scheme for connecting a hot water heat generator using biofuel to the existing city heat supply system is proposed to increase its reliability and survivability, which ensures the efficiency and reliability of operation of the heat supply system during the heating and summer periods. It is shown the possibility of operating a solid fuel heat generator with its power significantly less than the total heat load of the city's heating supply in several operating modes: during the heating period - for heating the return coolant at the inlet to the existing gas boiler house; in the summer period - for the needs of hot water supply in full; in the event of an emergency shutdown of a gas boiler house in winter - to maintain the viability of the heat supply system. The results of a calculation analysis of the operation of a 5,0 MW biofuel heat generator under different operating modes are presented. Heating the return coolant by 4...5 °C in winter, in addition to saving natural gas, prevents low-temperature corrosion of existing gas boilers. In the event of an emergency lack of natural gas supply, the combustion of wood chips ensures the production of thermal energy at the level of thermal losses of the heating network while maintaining the coolant temperature at least 3 °C at the calculated external air temperature. Thanks to the accumulation of thermal energy at night in the summer period in the volume of heating network pipes as a buffer tank, compensation for peak hot water consumption is provided with the available power of the solid fuel boiler house equal to the average load of the hot water supply system. When implementing a project to back up the heat supply system in Lutsk using a combined thermal scheme for connecting a solid fuel boiler house, an increase in the reliability and viability of the system and natural gas savings of 40,5% during a year of operation were achieved

Dynamic model of magnetic transmission

In the work, a non-contact electromechanical energy converter with permanent magnets, which is known as magnetic transmission, is studied. Magnetic transmissions have certain structural advantages compared to mechanical transmissions, namely: high reliability, efficiency, lower losses, non-contact transmission of mechanical power, no maintenance costs, and simplicity of construction. The use of magnetic transmissions for systems of conversion of low-potential mechanical energy into electrical energy is especially relevant: wind energy, water energy, energy of mechanical vibrations, etc. The use of magnetic gearboxes in autonomous wind power plants can be more promising from an economic and technical point of view compared to traditional mechanical transmissions. A numerical simulation mathematical model of magnetic transmission with permanent magnets has been developed. The use of magnetic transmission, for example, for autonomous wind power systems allows to increase the reliability of the operation of such installations, reduce operating costs and increase the efficiency of their operation. In emergency modes of operation, the use of magnetic transmission allows to avoid destruction or emergency shutdowns of electrical equipment. The developed simulation model of magnetic transmission takes into account the pulsations of the electromagnetic moment due to the discrete structure of the magnetic transmission and the change of the model parameters when the input moment changes: pulsations, losses in the magnetic core and permanent magnets, the change of the load angle and the transmitted electromagnetic moment. A feature of the developed model of the magnetic transmission system is that a change in the load of the electric power source leads to a change in the operating point on the mechanical characteristics of the rotor of the wind turbine. Conversely, when the wind parameters change, the output parameters of the source of electrical energy change: power, voltage, current and electromagnetic moment.

Modelling of foundation damping in time-domain analysis of monopile supported offshore wind turbine structures

Foundation damping holds large potential for design optimisations of monopile-supported offshore wind turbine structures. However, the contribution of foundation damping is not well understood, in part due to lack of suitable method for incorporating foundation damping in the time-domain analysis of wind turbine structures. This paper presents a practical approach for this purpose in which a dashpot is attached in parallel to each p-y spring along the monopile. In this way, the distributed soil-pile interaction stiffness and damping are accurately modelled. To demonstrate the validity of the proposed approach, a case study exploring the influence of foundation damping on the dynamic response of an IEA 15 MW reference turbine founded on monopile is carried out. The results demonstrate that the foundation damping has relatively limited impact on the overall dynamic response and fatigue loads in power production states. However, inclusion of foundation damping is shown to significantly reduce the structural response after emergency shutdown and under parked conditions. The findings of the case study show promising potential for wind turbine structure design optimization through consideration of foundation damping.

A probabilistic approach to optimal emergency shutdown valve configuration for pressurised CO2 pipelines

This study presents a multi-objective optimisation technique for determining the optimal number of in-line Emergency Shutdown Valves (ESDVs) for pressurised CO2 pipelines, aiming to balance risk associated with pipeline failure against the valve cost based on treating the risk as a probabilistic variable. Using standard Probability Density Functions (PDFs) to model the uncertainties inherent in pipeline characteristics and operating conditions, we perform a Monte Carlo simulation involving the random sampling from these PDFs to derive a probabilistic distribution of risk. This method contrasts with traditional deterministic methods that rely on assuming the worst-case failure scenario or pre-determining an averaged expected risk level — typically calculated by summing the products of failure frequencies and consequence magnitudes for various representative failure scenarios. The proposed approach integrates the risks of all possible failure scenarios directly into the optimisation process without such assumptions or pre-determinations, assessing them collectively based on their individual probabilities of occurrence. Our findings illustrate that the proposed technique allows for more reliable and effective ESDV configurations compared to the traditional methods. This approach not only facilitates safer CO2 transport within the context of Carbon Capture, Utilisation and Storage but also offers a framework for optimising pipeline ESDV configurations in general.