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Estimation of shutdown schedule to remove fouling layers of heat exchangers using risk-based inspection (RBI)Elwerfalli, A., Alsadaie, S., Mujtaba, Iqbal M. 28 March 2022 (has links)
Yes / Oil and Gas plants consist of a set of heat exchangers, which are used in recovering the waste heat from product streams to preheat the oil. The heat transfer coefficient of exchangers declines considerably during the operation period due to fouling. Fouling in heat exchangers is a complex phenomenon due to the acceleration of many layers of chemical substances across tubes of heat exchangers resulting from chemical reactions and surface roughness. In this paper, the fouling process was determined as a critical failure in the heat exchanger. Failure is an accelerated fouling layer across the heat exchanger tubes, which can be the reason for the clogging of tubes. Hence, a risk assessment was conducted using the Risk-Based Inspection (RBI) approach to estimate the probability of fouling in heat exchangers. The results showed that the RBI approach can be used successfully to predict the suitable time to shut down the plant and conduct the fouling cleaning process.
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Effectiveness of central bank communication on financial markets in emerging economies, with a special focus on ChinaSu, Shiwei January 2018 (has links)
Central bank communication has become an important monetary policy tool. This is because it helps to improve the effectiveness of monetary policy by sharing information, which reduces uncertainty. Previous research on the topic has concentrated on central banks in developed economies, such as the Bank of England, the European Central Bank, and the Federal Reserve. This research contributes to the literature by providing insights from the perspective of emerging economies, where communications of Chinese and Indian central banks are examined. The first empirical chapter investigates the effectiveness of communication of People s Bank of China (PBOC) on Chinese financial markets: the interbank money market, the equity market, and foreign exchange markets, are analysed using time-series models. The main focus of the chapter includes an analysis of PBOC s credibility, construction of a new communication index on global economic outlook, more detailed communication indexes, and addressing how-to-communicate questions in the PBOC s communication strategies. The results indicate that the PBOC has credibility and its communication generally reduces volatility in these markets. The second empirical chapter looks at the role of the PBOC s communication in predicting policy rates, using an ordered probit model. The communication indexes constructed in the chapter cover both formal and informal communications of PBOC for 2009 to 2015 and a new communication index on money supply was also constructed. The main finding is that PBOC s communications (particularly on inflation) are useful for predicting PBOC s monetary policy stance. The money supply communication index has some, but not much predictability powers. Finally, the third empirical chapter compares central bank communications in China and India. The contribution of the chapter lies in the comparative analysis of two central banks communications of developing economies, which were overlooked in the extant literature. It shows that the communications on the countries monetary policy inclination have influence on macroeconomic variables of the countries, particularly, the short-term inflation expectations. The findings, therefore, suggest the effectiveness of communications as an unconventional monetary policy tool in emerging economies.
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Studying the Risk Management Model of Petrochemical Enterprises by Risk Base Inspection SystemChen, Kuo-Liang 24 August 2011 (has links)
ABSTRACT
Redirecting the inspection plan to place emphasis on high risk equipment items is not the only objective when implementing Risk Base Inspection (RBI). Rather it would be much more fruitful if company staff were educated to be equipped with the capability of identifying potential risks and were willing to actually put into real practice in eliminating all these potential threats to an enterprise. Since its release, the API-580 technology has seen growing acceptance and becomes a popular methodology in maintaining the mechanical integrity of pressure equipment and piping. In addition to U.S.A, many other country including European nations and Japan have also assimilated the same risk concepts into regulations that require plant operators to aim for practical performance of equipment management, not at the extent of obligations required by the government.
Such a risk-based concept is not just incorporated in regulations, when utilized in close conjunction with plant maintenance and inspection, becomes a powerful tool in helping determine optimal inspection intervals of pressure equipment. In order for the equipment management system to perform effectively, fundamental tasks such as failure mechanisms identification and effectiveness of inspection methods are keys to a successful RBI program. Some might question Risk Base Inspection (RBI) to be a conservative, less aggressive approach that rather than opting for more aggressive managerial methods, it recommends to focus on the whole life cycle of plant equipment.
Keywords: API-581¡BRBI¡Bbusiness risk¡Bbusiness administration¡Bquantitative analysis¡Bconsequence analysis¡Brisk base inspection
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Optimising Turnaround Maintenance (TAM) Scheduling of Gas plants in LibyaEl Werfalli, Abdelnaser A.K. January 2018 (has links)
Gas plants consist of several pieces of both critical static and rotating equipment, which operate continuously under severe operating conditions. These pieces of equipment are permanently subjected to be inspected and maintained during total shutdown of plant facilities to execute Turnaround Maintenance (TAM) event. The TAM is the largest maintenance activities used in most oil and gas companies in terms of both cost and time. Oil and gas companies have suffered losses in the production and enormity in the TAM cost due to duration and interval of TAM which have randomly estimated without taking the size and age of plants into account. Sirte Oil Company (SOC) was a good example and used as a reference point for other gas plants to achieve the aim of this thesis associated with optimising TAM scheduling for gas plants (decreasing duration and increasing interval of TAM) by implementing the TAM model.
The contribution of this research is in developing the TAM model, consisting of four stages, which is broken down into four main stages: First stage; removing Non-critical pieces of Equipment (NEs) from the Scope of Work (SoW) of TAM to proactive maintenance strategies. Second stage; selecting Critical Static pieces of Equipment (CSEs) that constitute the highest risk based on Risk-Based Inspection (RBI). Third stage; selecting Critical Rotating pieces of Equipment (CREs) that constitute the highest risk based on Risk-Based Failure (RBF). Fourth stage; defining the optimum duration and interval of TAM based on Failure Distributions (FDs).
Consequently, the TAM model developed in this study provides a novelty in the TAM event and decision making process. This is basically about optimisation of TAM scheduling in the medium and long-term, characterized by decreasing duration and increasing interval of TAM based on both CSEs and CREs to achieve the TAM model results. The result is the reduction in TAM cost and production losses, and the improvement in reliability and availability requirements of gas plants according to the residual life of critical equipment and operating conditions.
To ensure reliability and consistency of the TAM model, it was validated with three Libya-plants SOC and data from three published case studies. The results from the validation of the TAM model are consistent with the real duration and interval of TAM in most plants SOC. The research concludes that the developed TAM model is a reliable and applicable tool to assist decision-makers in the estimation of TAM scheduling for any a processing plant.
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Kritiska framgångsfaktorer för Business Intelligence i realtidJönsson, Ola, Lindelöf Holmqvist, Anton January 2018 (has links)
Den ökade mängden realtidsdata som bland annat IoT-utvecklingen för med sig gör business intelligence (BI) i realtid mer relevant än någonsin. Då många BI-projekt tenderar till att misslyckas är förståelse av kritiska framgångsfaktorer vitalt. Denna studie syftar till att undersöka vilka skillnader i kritiska framgångsfaktorer som utmärker implementationer av realtids-BI (RBI) system jämfört med BI-implementationer. Semistrukturerade intervjuer baserade på forskning kring framgångsfaktorer för BI har använts för att undersöka utmärkande drag för RBI. Studien har identifierat att RBI kräver en arkitektur designad för att stödja analys av strömmande data samt att RBI kräver ett mer visionärt och experimentellt förhållningssätt. Slutligen belyser studien att risken för feltolkning och felaktiga slutsatser ökar då beslut tas utifrån rådata. Därmed krävs en högre datakvalitet vid RBI för att data ska anses vara av en hållbar kvalitet. / The increased amount of real-time data, such as IoT's development, makes business intelligence (BI) in real-time more relevant than ever before. As many BI projects tend to fail, the understanding of critical success factors are vital. This study aims to investigate the differences in critical success factors that characterize implementations of real-time BI (RBI) systems versus BI implementations. Semi-structured interviews based on research of critical success factors for BI has been used to investigate distinguishing features for RBI. The study has identified that RBI requires an architecture designed to support analysis of streaming data and that a more visionary and experimental approach is required. Finally, the study highlights that the risk of misinterpretation and incorrect conclusions increases when decisions are taken based on raw data. Therefore, higher data quality is required to be considered to be a sustainable quality in the RBI context.
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Religiosity and Attitudes Toward AgingLauck, Amanda Marie 03 September 2008 (has links)
No description available.
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