Thesubsea dynamic riser base （SDRB） is an important piece of equipment for the floating production platform mooring system.One end is connected to the rigid pipeline, carrying a rigid pipeline thermal expansion load...Thesubsea dynamic riser base （SDRB） is an important piece of equipment for the floating production platform mooring system.One end is connected to the rigid pipeline, carrying a rigid pipeline thermal expansion load and the other end is connected to a flexible riser, carrying the dynamic load of the flexible riser, so its function is a transition connection between the flexible riser and the rigid pipeline which fixes the flexible riser on the seabed. On the other hand. as a typical subsea product, the design will satisfythe requirements of the standards for subsea products. By studying the stress analysisphilosophy of the topside piping and subsea pipeline, a physical model and procedure for piping stress analysis of the SDRB have been established.The conditions of the adverse design load have been considered, and a combination of the static load from the rigid pipeline and the dynamic load flexibility has also been optimized. And a comparative analysis between the AMSE, DNV and API standards for piping stress with the checking rules has been done.Because theSDRB belongs to the subsea pipeline terminal product, the use of DNV standards to check its process piping stress is recommended. Finally, the process piping stress of the SDRB has been calculated, and the results show that the jacket pipe and the carrier pipe stress of the SDRB process piping satisfy the DNV standards as a whole.The bulkhead cannot be accurately simulated by the AutoPIPE software which uses the FEA software ANSYS inthe detailed analysis, but the checking results will still meet the requirements of the DNV standards.展开更多
Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bond...Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bonding mechanism of the cold welding sealing process （CWSP） is investigated and compared with the experimental results obtained from the bonding interface analysis. An orthogonal experiment is conducted to observe the effects of various parameters, including the sealing gap, sealing length, sealing diameter, and sealing velocity on bonding strength. A method with the utilization of saturated vapor pressure inside a copper tube is proposed to evaluate bonding strength. A corresponding finite element model is developed to investigate the effects of sealing gap and sealing velocity on plastic deformation during the cold welding process. Effects of various parameters on the bonding strength are determined and it is found that the sealing gap is the most critical factor and that the sealing velocity contributes the least effect. The best parameter combination （AIB3CID3, with a 0.5 mm sealing gap, 6 mm sealing length, 3.8 mm sealing diameter, and 50 mm/s sealing velocity） is derived within the experimental parameters. Plastic deformation results derived from the finite element model are consistent with those from the experiment. The instruction for the CWSP of heat pipes and the design of sealing dies of heat pipes are provided.展开更多
Due to the complex and dangerous characteristics of chemical process production process, the installation design of chemical process pipeline is doomed to be highly professional, and the installation management work o...Due to the complex and dangerous characteristics of chemical process production process, the installation design of chemical process pipeline is doomed to be highly professional, and the installation management work of installation workers is actually difficult. Therefore, it is necessary to build a scientific and reasonable installation management method based on the mastery of skilled professional technology,Thus, it can ensure the safety of chemical production process and improve the quality of chemical products.展开更多
As an important pillar of social and economic growth, chemical enterprises have their own unique industrial characteristics, which makes chemical enterprises get attention and attention. However, in the process of oil...As an important pillar of social and economic growth, chemical enterprises have their own unique industrial characteristics, which makes chemical enterprises get attention and attention. However, in the process of oil refining and chemical process pipeline installation, because the selected process is not scientific and reasonable, and the quality inspection fails to meet the relevant standards, there are many problems in the process pipeline quality. Even in serious cases, it will have a serious impact on the subsequent use of the pipeline and threaten the safety of people's lives and property. In this case, we should pay attention to strengthen the management of chemical process pipeline construction, and focus on the strict control of pipeline installation quality, so as to improve the overall quality of pipeline safety and provide important guarantee for the development of chemical enterprises.展开更多
Pore-scale particle migration in piping is the main reason of the suffusion-induced damage,which poses a significant threat to earth-rock dams.In order to investigate the micro-mechanism of piping seepage process,an i...Pore-scale particle migration in piping is the main reason of the suffusion-induced damage,which poses a significant threat to earth-rock dams.In order to investigate the micro-mechanism of piping seepage process,an improved fluid-solid coupling discrete element method is proposed in this paper.In this method,particles in a packed model are divided into coarse-and fine particle groups.Pores can be defined based on the coordinates of the coarse particles and the Delaunay triangulation algorithm.A pore density flow method is introduced to calculate the overall fluid pressure of each pore and the fluid flow via pore throats.Further,the drag force on fine particles inside a pore can be calculated according to the fluid velocities of the neighboring four pore throats.The proposed method was implemented in the discrete element software MatDEM,and was successfully used to simulate fine particle migration of piping,the particle loss process,and the related variation of permeability coefficient.The pore-jamming phenomenon during the fine particle migration is observed.The model provides an effective way for the numerical analysis and mechanism study of piping seepage process at the pore scale.展开更多
基金financially supported by Offshore Engineering Equipment Scientific Research Project--Topic on Subsea Production System DesignKey Equipment Research & Development from Ministry of Industry and Information Technology of the People's Republic of China E-0813C003
文摘Thesubsea dynamic riser base （SDRB） is an important piece of equipment for the floating production platform mooring system.One end is connected to the rigid pipeline, carrying a rigid pipeline thermal expansion load and the other end is connected to a flexible riser, carrying the dynamic load of the flexible riser, so its function is a transition connection between the flexible riser and the rigid pipeline which fixes the flexible riser on the seabed. On the other hand. as a typical subsea product, the design will satisfythe requirements of the standards for subsea products. By studying the stress analysisphilosophy of the topside piping and subsea pipeline, a physical model and procedure for piping stress analysis of the SDRB have been established.The conditions of the adverse design load have been considered, and a combination of the static load from the rigid pipeline and the dynamic load flexibility has also been optimized. And a comparative analysis between the AMSE, DNV and API standards for piping stress with the checking rules has been done.Because theSDRB belongs to the subsea pipeline terminal product, the use of DNV standards to check its process piping stress is recommended. Finally, the process piping stress of the SDRB has been calculated, and the results show that the jacket pipe and the carrier pipe stress of the SDRB process piping satisfy the DNV standards as a whole.The bulkhead cannot be accurately simulated by the AutoPIPE software which uses the FEA software ANSYS inthe detailed analysis, but the checking results will still meet the requirements of the DNV standards.
基金Supported by National Natural Science Foundation of China(Grant Nos.51175186,51675185)Guangdong Provincial Natural Science Foundation of China(Grant No.S2013020012757)EU project PIIF-GA-2012-332304(Grant No.ESR332304)
文摘Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bonding mechanism of the cold welding sealing process （CWSP） is investigated and compared with the experimental results obtained from the bonding interface analysis. An orthogonal experiment is conducted to observe the effects of various parameters, including the sealing gap, sealing length, sealing diameter, and sealing velocity on bonding strength. A method with the utilization of saturated vapor pressure inside a copper tube is proposed to evaluate bonding strength. A corresponding finite element model is developed to investigate the effects of sealing gap and sealing velocity on plastic deformation during the cold welding process. Effects of various parameters on the bonding strength are determined and it is found that the sealing gap is the most critical factor and that the sealing velocity contributes the least effect. The best parameter combination （AIB3CID3, with a 0.5 mm sealing gap, 6 mm sealing length, 3.8 mm sealing diameter, and 50 mm/s sealing velocity） is derived within the experimental parameters. Plastic deformation results derived from the finite element model are consistent with those from the experiment. The instruction for the CWSP of heat pipes and the design of sealing dies of heat pipes are provided.
文摘Due to the complex and dangerous characteristics of chemical process production process, the installation design of chemical process pipeline is doomed to be highly professional, and the installation management work of installation workers is actually difficult. Therefore, it is necessary to build a scientific and reasonable installation management method based on the mastery of skilled professional technology,Thus, it can ensure the safety of chemical production process and improve the quality of chemical products.
文摘As an important pillar of social and economic growth, chemical enterprises have their own unique industrial characteristics, which makes chemical enterprises get attention and attention. However, in the process of oil refining and chemical process pipeline installation, because the selected process is not scientific and reasonable, and the quality inspection fails to meet the relevant standards, there are many problems in the process pipeline quality. Even in serious cases, it will have a serious impact on the subsequent use of the pipeline and threaten the safety of people's lives and property. In this case, we should pay attention to strengthen the management of chemical process pipeline construction, and focus on the strict control of pipeline installation quality, so as to improve the overall quality of pipeline safety and provide important guarantee for the development of chemical enterprises.
基金supported by the National Natural Science Foundation of China(42222707)State Key Laboratory for Geo-Mechanics and Deep Underground Engineering,China University of Mining&Technology(SKLGDUEK2117).
文摘Pore-scale particle migration in piping is the main reason of the suffusion-induced damage,which poses a significant threat to earth-rock dams.In order to investigate the micro-mechanism of piping seepage process,an improved fluid-solid coupling discrete element method is proposed in this paper.In this method,particles in a packed model are divided into coarse-and fine particle groups.Pores can be defined based on the coordinates of the coarse particles and the Delaunay triangulation algorithm.A pore density flow method is introduced to calculate the overall fluid pressure of each pore and the fluid flow via pore throats.Further,the drag force on fine particles inside a pore can be calculated according to the fluid velocities of the neighboring four pore throats.The proposed method was implemented in the discrete element software MatDEM,and was successfully used to simulate fine particle migration of piping,the particle loss process,and the related variation of permeability coefficient.The pore-jamming phenomenon during the fine particle migration is observed.The model provides an effective way for the numerical analysis and mechanism study of piping seepage process at the pore scale.
