在石油化工领域,管道输送系统的弯管非常容易遭受管内固体颗粒的冲蚀,使管道承压能力降低,增加管道输送的安全风险。首先对油气行业广泛采用的API RP 14E和DNV冲蚀准则进行了描述和分析,进而概述了国内外被较多专家学者提及的弯管固体...在石油化工领域,管道输送系统的弯管非常容易遭受管内固体颗粒的冲蚀,使管道承压能力降低,增加管道输送的安全风险。首先对油气行业广泛采用的API RP 14E和DNV冲蚀准则进行了描述和分析,进而概述了国内外被较多专家学者提及的弯管固体颗粒冲蚀理论和模型,包括经典的微切削理论模型、变形磨损理论模型以及适用性较强的E/CRC冲蚀模型和Oka冲蚀模型。并在此基础上,对不同冲蚀理论和模型进行了对比和分析,指出各个冲蚀理论模型之间的内在联系,以及各自的优势和缺陷。在工程应用方面,对近年来工业中常见的防冲蚀涂层和防冲蚀几何结构进行了系统的归纳和总结。其中,防冲蚀涂层包括金属防冲蚀涂层、非金属防冲蚀涂层以及复合材料防冲蚀涂层,防冲蚀几何结构包括涡旋结构和各种形式的仿生肋条结构。最后,对弯管固体颗粒冲蚀理论模型的研究方向、纳米防冲蚀涂层以及仿生学防冲蚀肋条结构的发展前景进行了展望。为油气管道系统完整性管理、油气储运安全和流动保障等方面的研究提供借鉴。展开更多
Sediment resuspension is commonly assumed to be eroded from the seabed surface by an excess bottom shear stress and evolves in layers from the top down. Although considerable investigations have argued the importance ...Sediment resuspension is commonly assumed to be eroded from the seabed surface by an excess bottom shear stress and evolves in layers from the top down. Although considerable investigations have argued the importance of wave-induced seabed fluidization in affecting the sediment resuspension, few studies have been able to reliably evaluate its quantitative contribution till now. Attempt is made to preliminarily quantify the contribution of fluidization to resuspension using a series of large-scale wave flume experiments. The experimental results indicated that fluidization of the sandy silts of the Huanghe Delta account for 52.5% and 66.8% of the total resuspension under model scales of 4/20 and 6/20（i.e., relative water depth： the ratio of wave height to water depth）, respectively. Some previously reported results obtained using the same flume and sediments are also summarized for a contrastive analysis, through which not only the positive correlation is confirmed, but also a parametric equation for depicting the relationship between the contribution of fluidization and the model scale is established. Finally, the contribution of fluidization is attributed to two physical mechanisms：（1） an attenuation of the erosion resistance of fluidized sediments in surface layers due to the disappearing of original cohesion and the uplifting effect resulting from upward seepage flows, and（2） seepage pumping of fines from the interior to the surface of fluidized seabed.展开更多
The elbow erosion seriously jeopardizes the safe and stable operation of water–slag discharge pipeline of the coal gasification system.This work simulated water–slag elbow characteristics with various slag injection...The elbow erosion seriously jeopardizes the safe and stable operation of water–slag discharge pipeline of the coal gasification system.This work simulated water–slag elbow characteristics with various slag injection positions by simulating five simplified and representative erosion categories,including A-type horizontal-vertical elbow with an upstream flow,B-type horizontal-vertical elbow with a downstream flow,C-type vertical-horizontal elbow with an upstream flow,D-type vertical-horizontal elbow with a downstream flow and E-type horizontal-horizontal elbow.Compared with the C/D-type elbow,where particles were injected uniformly,the A-type elbow and E-type elbow were found to increase erosion rate,while the B-type elbow decreases erosion rate.An interesting discovery is that the elbow erosion rate is relatively low for small particles when particles are injected from the middle and bottom positions of the inlet section of the elbow.Based on the observation,a novel preceding rotating sheet structure was developed to regulate the particle injection position.It shows an excellent anti-erosion performance by reducing the maximum erosion rate of particles with diameters of 50,100,and 200μm by 23%,35%,and 43%,respectively.展开更多
文摘在石油化工领域,管道输送系统的弯管非常容易遭受管内固体颗粒的冲蚀,使管道承压能力降低,增加管道输送的安全风险。首先对油气行业广泛采用的API RP 14E和DNV冲蚀准则进行了描述和分析,进而概述了国内外被较多专家学者提及的弯管固体颗粒冲蚀理论和模型,包括经典的微切削理论模型、变形磨损理论模型以及适用性较强的E/CRC冲蚀模型和Oka冲蚀模型。并在此基础上,对不同冲蚀理论和模型进行了对比和分析,指出各个冲蚀理论模型之间的内在联系,以及各自的优势和缺陷。在工程应用方面,对近年来工业中常见的防冲蚀涂层和防冲蚀几何结构进行了系统的归纳和总结。其中,防冲蚀涂层包括金属防冲蚀涂层、非金属防冲蚀涂层以及复合材料防冲蚀涂层,防冲蚀几何结构包括涡旋结构和各种形式的仿生肋条结构。最后,对弯管固体颗粒冲蚀理论模型的研究方向、纳米防冲蚀涂层以及仿生学防冲蚀肋条结构的发展前景进行了展望。为油气管道系统完整性管理、油气储运安全和流动保障等方面的研究提供借鉴。
基金The National Natural Science Foundation of China under contract Nos 41272316 and 41372287the Joint Fund of NSFC and Marine Science Research Centers of Shandong Province of China under contract No.U1606401the Key Research and Development Program of Shandong Province of China under contract No.2016ZDJS09A03
文摘Sediment resuspension is commonly assumed to be eroded from the seabed surface by an excess bottom shear stress and evolves in layers from the top down. Although considerable investigations have argued the importance of wave-induced seabed fluidization in affecting the sediment resuspension, few studies have been able to reliably evaluate its quantitative contribution till now. Attempt is made to preliminarily quantify the contribution of fluidization to resuspension using a series of large-scale wave flume experiments. The experimental results indicated that fluidization of the sandy silts of the Huanghe Delta account for 52.5% and 66.8% of the total resuspension under model scales of 4/20 and 6/20（i.e., relative water depth： the ratio of wave height to water depth）, respectively. Some previously reported results obtained using the same flume and sediments are also summarized for a contrastive analysis, through which not only the positive correlation is confirmed, but also a parametric equation for depicting the relationship between the contribution of fluidization and the model scale is established. Finally, the contribution of fluidization is attributed to two physical mechanisms：（1） an attenuation of the erosion resistance of fluidized sediments in surface layers due to the disappearing of original cohesion and the uplifting effect resulting from upward seepage flows, and（2） seepage pumping of fines from the interior to the surface of fluidized seabed.
基金the National Natural Science Foundation of China(grant No.22278332)Shaanxi Province's Key Research and Development Plan(grant No.2023-YBGY-317,2023-YBGY-175)+1 种基金Natural Science Basic Research Program of Shaanxi(grant No.2020JQ-597)Natural Science Foundation of Shaanxi Provincial Department of Education(grant No.23JK0723).
文摘The elbow erosion seriously jeopardizes the safe and stable operation of water–slag discharge pipeline of the coal gasification system.This work simulated water–slag elbow characteristics with various slag injection positions by simulating five simplified and representative erosion categories,including A-type horizontal-vertical elbow with an upstream flow,B-type horizontal-vertical elbow with a downstream flow,C-type vertical-horizontal elbow with an upstream flow,D-type vertical-horizontal elbow with a downstream flow and E-type horizontal-horizontal elbow.Compared with the C/D-type elbow,where particles were injected uniformly,the A-type elbow and E-type elbow were found to increase erosion rate,while the B-type elbow decreases erosion rate.An interesting discovery is that the elbow erosion rate is relatively low for small particles when particles are injected from the middle and bottom positions of the inlet section of the elbow.Based on the observation,a novel preceding rotating sheet structure was developed to regulate the particle injection position.It shows an excellent anti-erosion performance by reducing the maximum erosion rate of particles with diameters of 50,100,and 200μm by 23%,35%,and 43%,respectively.
