The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform
Tianxi Che - One of the best experts on this subject based on the ideXlab platform.
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a new dry tray pressure drop model of Float Valve trays
Aiche Journal, 2013Co-Authors: Ju Wang, Yixua Tang, Yansheng Liu, Rui Cao, Tianxi CheAbstract:An accurate prediction of the dry pressure drop is very important for consideration of Valve trays and for calculations in distillation field. Therefore, in this article, a series of hydraulic experiments were first conducted to reveal that the intermediate state during the Valve opening process is closely related to the dry tray pressure drop under great Valve weight. Then, a rigorous force analysis was made to show that Euler number is related only to the Valve's position at the balance points for a certain Valve type. Third, a new model for prediction of the dry tray pressure drop—which considers for the first time the influence of the intermediate state—was developed and then simplified for the purpose of convenient utilizations. Finally, the new model and its simplified form were tested by comparisons with the experimental results. The agreements are good, with the mean deviations being <5%. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2694–2705, 2013
Rungrujira Nisi - One of the best experts on this subject based on the ideXlab platform.
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Basic design of subsea BOP stack with RCD for riserless drilling
University of Stavanger Norway, 2013Co-Authors: Rungrujira NisiAbstract:Master's thesis in Offshore technologyReelwell Riserless drilling concept has been proposed to overcome the economic challenge of drilling through the thick salt layer. The concept shall bases on RDM method, which is a new drilling method with the concentric drill string other special design tool such as Rotating control devices and Double Float Valve. The concentric drill string consists of outer conventional pipe joints an inner string specially designed for RDM that shall allow the “return” through the inner pipe. This shall eliminate the need of marine riser, which results in significant cost savings by exclusion of riser related costs and enables us to use smaller rigs with much lower day rate for ultra deep-water drilling operations. There would also be a considerable mud cost reduction and rig space saving as there is no riser to be filled up with drilling mud. The study has reviewed the conventional drilling procedure, the case study's working condition and defined the Basic Design of Subsea BOP stack with Rotating control device for Reelwell-Riserless drilling, to achieve reasonable reliability and performance to mitigate risk in the operation. The BOP control system is also reviewed and proposed a new technology to improve its efficiency in the new working environment
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Basic design of subsea BOP stack with RCD for riserless drilling
University of Stavanger Norway, 2013Co-Authors: Rungrujira NisiAbstract:Reelwell Riserless drilling concept has been proposed to overcome the economic challenge of drilling through the thick salt layer. The concept shall bases on RDM method, which is a new drilling method with the concentric drill string other special design tool such as Rotating control devices and Double Float Valve. The concentric drill string consists of outer conventional pipe joints an inner string specially designed for RDM that shall allow the “return” through the inner pipe. This shall eliminate the need of marine riser, which results in significant cost savings by exclusion of riser related costs and enables us to use smaller rigs with much lower day rate for ultra deep-water drilling operations. There would also be a considerable mud cost reduction and rig space saving as there is no riser to be filled up with drilling mud. The study has reviewed the conventional drilling procedure, the case study's working condition and defined the Basic Design of Subsea BOP stack with Rotating control device for Reelwell-Riserless drilling, to achieve reasonable reliability and performance to mitigate risk in the operation. The BOP control system is also reviewed and proposed a new technology to improve its efficiency in the new working environment
Ju Wang - One of the best experts on this subject based on the ideXlab platform.
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a new dry tray pressure drop model of Float Valve trays
Aiche Journal, 2013Co-Authors: Ju Wang, Yixua Tang, Yansheng Liu, Rui Cao, Tianxi CheAbstract:An accurate prediction of the dry pressure drop is very important for consideration of Valve trays and for calculations in distillation field. Therefore, in this article, a series of hydraulic experiments were first conducted to reveal that the intermediate state during the Valve opening process is closely related to the dry tray pressure drop under great Valve weight. Then, a rigorous force analysis was made to show that Euler number is related only to the Valve's position at the balance points for a certain Valve type. Third, a new model for prediction of the dry tray pressure drop—which considers for the first time the influence of the intermediate state—was developed and then simplified for the purpose of convenient utilizations. Finally, the new model and its simplified form were tested by comparisons with the experimental results. The agreements are good, with the mean deviations being <5%. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2694–2705, 2013
Nilce Regina Da ,silva - One of the best experts on this subject based on the ideXlab platform.
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A metodology studies for evaluation of domestic water meter under-registration in water systems
2010Co-Authors: Nilce Regina Da ,silvaAbstract:A avaliação dos fatores que provocam erros de medição de vazão tem fundamental importância para o controle de perdas nos sistemas de abastecimento público de água. A imprecisão na medição feita pelos hidrômetros residenciais, notadamente a submedição, representa uma parcela significativa das perdas aparentes. A utilização de reservatórios domésticos é um dos principais responsáveis pela submedição, devido ao amortecimento das vazões que provocam no abastecimento dos domicílios, fazendo com que os hidrômetros funcionem com vazões muito baixas, menores do que as que ocorrem em um sistema abastecido diretamente pela rede. Esse amortecimento é agravado pelo controle do nível desses reservatórios, que, geralmente, é feito por válvulas do tipo bóia, com vazão proporcional ao nível do reservatório, cujo impacto na submedição tem sido pouco estudado. Na literatura são encontradas poucas referências sobre essas válvulas. Neste trabalho procurou-se estudar a submedição provocada pelas válvulas com bóia em reservatórios domiciliares. Para isso simulou-se o abastecimento de residências a partir das curvas de vazão das válvulas de bóia e do consumo de água pelas residências. Para levantamento das curvas de vazão das válvulas construiu-se um aparato experimental que permitiu realizar o levantamento das vazões em função do nível do reservatório. O perfil de consumo das residências foi levantado a partir do registro das vazões consumidas em residências sem reservatório, utilizando-se data loggers. As curvas de erro de medição dos hidrômetros utilizados nas residências estudadas foram levantadas no laboratório da CAESB. Com os dados obtidos nas simulações, pôde-se estimar a submedição provocada pelas baixas vazões que passam pelas bóias, bem como analisar o efeito de diversas combinações entre os tipos de bóia ensaiados, os perfis de consumo e as curvas de erros dos hidrômetros. Os resultados alcançados evidenciaram que a submedição, provocada pelas válvulas do tipo bóia, pode ser agravada pela combinação entre o perfil de consumo do domicílio, o modelo de reservatório e a exatidão do hidrômetro utilizado. O uso de diferentes marcas e diâmetros de bóias apresentou pequena influência na submedição. _________________________________________________________________________________ ABSTRACTThe evaluation of the factors that cause the measurements errors has fundamental importance for the loss control in public water supply systems. The imprecision in the measurement done by the domestic water meters, specially the under-registration, represents a significant portion of the apparent losses and it will be the most relevant aspect in this work which intend to contribute for target the efforts in the combat to the water meter under-registration. The use of domestic roof tanks is responsible for the reduction of the water supply flow rates to the houses, causing the water meters to work with flows smaller than the ones that would occur in a water system supplied directly from the water distribution network. The control of the level of these roof tanks usually is done by Float Valves, which are flow Valves with discharge proportional to the tank water level. In this work, a study was carried out aiming to establish the influence of the different types of the Float Valves, used in the control of the levels of the domestic roof tanks. For this the house supply was simulated based on the curves of Float Valve and the water consumption by households. To determine the Valve flow curves an experimental apparatus was set up which allowed to plot the flow rate curves as function of tank levels. The profile of household water consumptions was obtained from the record of flow consumed in homes directly supplied, using data loggers. The curves of errors of the measuring meters used in homes were raised in the laboratory of CAESB. Based on the obtained in the simulations, it was possible to estimate the under-registration caused by low flow rates through the Valves, and to analyze the effect of different combinations between the types of the Valves tested, the consumption profiles and the meter errors. The results showed that the under-registration caused by the Float Valves can be aggravated by the combination of the consumption profile, type of tank and accuracy of meters used. The use of different diameters and Valve brands showed a lower small influence in under-registration
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A metodology studies for evaluation of domestic water meter under-registration in water systems
2008Co-Authors: Nilce Regina Da ,silvaAbstract:Dissertação (mestrado)—Universidade de Brasília, Departamento de Engenharia Civil e Ambiental, 2008.A avaliação dos fatores que provocam erros de medição de vazão tem fundamental importância para o controle de perdas nos sistemas de abastecimento público de água. A imprecisão na medição feita pelos hidrômetros residenciais, notadamente a submedição, representa uma parcela significativa das perdas aparentes. A utilização de reservatórios domésticos é um dos principais responsáveis pela submedição, devido ao amortecimento das vazões que provocam no abastecimento dos domicílios, fazendo com que os hidrômetros funcionem com vazões muito baixas, menores do que as que ocorrem em um sistema abastecido diretamente pela rede. Esse amortecimento é agravado pelo controle do nível desses reservatórios, que, geralmente, é feito por válvulas do tipo bóia, com vazão proporcional ao nível do reservatório, cujo impacto na submedição tem sido pouco estudado. Na literatura são encontradas poucas referências sobre essas válvulas. Neste trabalho procurou-se estudar a submedição provocada pelas válvulas com bóia em reservatórios domiciliares. Para isso simulou-se o abastecimento de residências a partir das curvas de vazão das válvulas de bóia e do consumo de água pelas residências. Para levantamento das curvas de vazão das válvulas construiu-se um aparato experimental que permitiu realizar o levantamento das vazões em função do nível do reservatório. O perfil de consumo das residências foi levantado a partir do registro das vazões consumidas em residências sem reservatório, utilizando-se data loggers. As curvas de erro de medição dos hidrômetros utilizados nas residências estudadas foram levantadas no laboratório da CAESB. Com os dados obtidos nas simulações, pôde-se estimar a submedição provocada pelas baixas vazões que passam pelas bóias, bem como analisar o efeito de diversas combinações entre os tipos de bóia ensaiados, os perfis de consumo e as curvas de erros dos hidrômetros. Os resultados alcançados evidenciaram que a submedição, provocada pelas válvulas do tipo bóia, pode ser agravada pela combinação entre o perfil de consumo do domicílio, o modelo de reservatório e a exatidão do hidrômetro utilizado. O uso de diferentes marcas e diâmetros de bóias apresentou pequena influência na submedição. _________________________________________________________________________________ ABSTRACTThe evaluation of the factors that cause the measurements errors has fundamental importance for the loss control in public water supply systems. The imprecision in the measurement done by the domestic water meters, specially the under-registration, represents a significant portion of the apparent losses and it will be the most relevant aspect in this work which intend to contribute for target the efforts in the combat to the water meter under-registration. The use of domestic roof tanks is responsible for the reduction of the water supply flow rates to the houses, causing the water meters to work with flows smaller than the ones that would occur in a water system supplied directly from the water distribution network. The control of the level of these roof tanks usually is done by Float Valves, which are flow Valves with discharge proportional to the tank water level. In this work, a study was carried out aiming to establish the influence of the different types of the Float Valves, used in the control of the levels of the domestic roof tanks. For this the house supply was simulated based on the curves of Float Valve and the water consumption by households. To determine the Valve flow curves an experimental apparatus was set up which allowed to plot the flow rate curves as function of tank levels. The profile of household water consumptions was obtained from the record of flow consumed in homes directly supplied, using data loggers. The curves of errors of the measuring meters used in homes were raised in the laboratory of CAESB. Based on the obtained in the simulations, it was possible to estimate the under-registration caused by low flow rates through the Valves, and to analyze the effect of different combinations between the types of the Valves tested, the consumption profiles and the meter errors. The results showed that the under-registration caused by the Float Valves can be aggravated by the combination of the consumption profile, type of tank and accuracy of meters used. The use of different diameters and Valve brands showed a lower small influence in under-registration
. Milici - One of the best experts on this subject based on the ideXlab platform.
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Experimental Investigation for Local Tank Inflow Model
The Authors. Published by Elsevier Ltd., 2014Co-Authors: De Marchis M., Fontanazza C.m., Freni G., . MiliciAbstract:AbstractIn the present paper the effect of private roof tanks and of the Float Valve characteristics on apparent losses due to water meter errors was investigated via an experimental study. The tests were carried out at the Environmental Hydraulic Laboratory of the University of Enna (Italy), on a high-density polyethylene (HDPE 100 PN16) looped distribution network. The experimental results showed that network pressure plays an important role in the characterisation of the Floating ball Valve emitter law, but the tank operating condition is the most relevant aspect to be considered mainly for water meter error evaluation
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Experimental Investigation for Local Tank Inflow Model
'Elsevier BV', 2014Co-Authors: De Marchis M., Freni G., Fontanazza C., . MiliciAbstract:In the present paper the effect of private roof tanks and of the Float Valve characteristics on apparent losses due to water meter errors was investigated via an experimental study. The tests were carried out at the Environmental Hydraulic Laboratory of the University of Enna (Italy), on a high-density polyethylene (HDPE 100 PN16) looped distribution network. The experimental results showed that network pressure plays an important role in the characterisation of the Floating ball Valve emitter law, but the tank operating condition is the most relevant aspect to be considered mainly for water meter error evaluation. (C) 2014 The Authors. Published by Elsevier Ltd