A large data bank of more than 700 gas-condensate samples collected from literature and experiments was established.On this basis,empirical correlations and equations of state commonly used to calculate dew-point pres...A large data bank of more than 700 gas-condensate samples collected from literature and experiments was established.On this basis,empirical correlations and equations of state commonly used to calculate dew-point pressure(DPP)were evaluated.A new model for estimating DPP was proposed.All the empirical correlations and the Peng-Robinson state equation were compared,and sensitivity of parameters was analyzed.The current standards used to identify gas condensate were evaluated and found to be not accurate enough.The Peng-Robinson state equation has no unique solution and is affected by multiple factors such as the characterization of C7+components and the splitting scheme.The Nemeth-Kennedy correlation has the highest accuracy when applied to the data bank established in this study,followed by Elsharkawy correlation and Godwin correlation.While Shokir correlation cannot be used for samples without C7+components,it is therefore the lowest in accuracy.The newly proposed model has an average absolute error,root mean square error and coefficient of determination of 7.5%,588,and 0.87,respectively,and is better than the above four correlations statistically.The proposed model proved to be more accurate and valid when compared to experimental results and simulation with the Peng-Robinson state equation.展开更多
随着能源与环境问题的日益突出,在保证安全性的前提下,实现车身轻量化是汽车工业发展的主要方向之一。先进高强钢(AHSS)兼具高强度和良好的成形性,是最重要的汽车轻量化材料,然而,长期以来突出的镀锌质量问题使其发展面临巨大挑战,特别...随着能源与环境问题的日益突出,在保证安全性的前提下,实现车身轻量化是汽车工业发展的主要方向之一。先进高强钢(AHSS)兼具高强度和良好的成形性,是最重要的汽车轻量化材料,然而,长期以来突出的镀锌质量问题使其发展面临巨大挑战,特别是对于高等级AHSS而言,表面质量控制问题始终未能得到有效解决。在生产过程中,钢中Si、Mn、Al等亲氧性元素会发生选择性氧化,在退火过程中表现尤为显著。由于表面氧化物的形成,镀锌液与基体的接触与润湿受到阻碍,进而抑制了Fe 2Al 5-x Z x中间层的形成,导致漏镀和镀层结合力差等镀锌缺陷。退火选择性氧化问题被普遍认为是制约AHSS可镀性的最大障碍。基于近20年的相关研究,首先介绍了退火选择性氧化与可镀性的内在联系,包括表面氧化物覆盖率、形貌及尺寸和化学态对可镀性的影响,而后对AHSS退火选择性氧化的影响因素及改善措施进行了综述和分析,包括退火露点和合金元素调控的影响及调控,最后对改善退火选择性氧化以获得高可镀性、高表面质量AHSS的技术路径进行了展望。展开更多
基金Supported by the Kuwait University(Research Grant No.GE 01/17)through the Petroleum Fluid Research Center(PFRC)
文摘A large data bank of more than 700 gas-condensate samples collected from literature and experiments was established.On this basis,empirical correlations and equations of state commonly used to calculate dew-point pressure(DPP)were evaluated.A new model for estimating DPP was proposed.All the empirical correlations and the Peng-Robinson state equation were compared,and sensitivity of parameters was analyzed.The current standards used to identify gas condensate were evaluated and found to be not accurate enough.The Peng-Robinson state equation has no unique solution and is affected by multiple factors such as the characterization of C7+components and the splitting scheme.The Nemeth-Kennedy correlation has the highest accuracy when applied to the data bank established in this study,followed by Elsharkawy correlation and Godwin correlation.While Shokir correlation cannot be used for samples without C7+components,it is therefore the lowest in accuracy.The newly proposed model has an average absolute error,root mean square error and coefficient of determination of 7.5%,588,and 0.87,respectively,and is better than the above four correlations statistically.The proposed model proved to be more accurate and valid when compared to experimental results and simulation with the Peng-Robinson state equation.
文摘随着能源与环境问题的日益突出,在保证安全性的前提下,实现车身轻量化是汽车工业发展的主要方向之一。先进高强钢(AHSS)兼具高强度和良好的成形性,是最重要的汽车轻量化材料,然而,长期以来突出的镀锌质量问题使其发展面临巨大挑战,特别是对于高等级AHSS而言,表面质量控制问题始终未能得到有效解决。在生产过程中,钢中Si、Mn、Al等亲氧性元素会发生选择性氧化,在退火过程中表现尤为显著。由于表面氧化物的形成,镀锌液与基体的接触与润湿受到阻碍,进而抑制了Fe 2Al 5-x Z x中间层的形成,导致漏镀和镀层结合力差等镀锌缺陷。退火选择性氧化问题被普遍认为是制约AHSS可镀性的最大障碍。基于近20年的相关研究,首先介绍了退火选择性氧化与可镀性的内在联系,包括表面氧化物覆盖率、形貌及尺寸和化学态对可镀性的影响,而后对AHSS退火选择性氧化的影响因素及改善措施进行了综述和分析,包括退火露点和合金元素调控的影响及调控,最后对改善退火选择性氧化以获得高可镀性、高表面质量AHSS的技术路径进行了展望。
