Floating photovoltaic platform is recognized as one of the most potential technology development direction in the industry. How to maintain the strength and stability of the structure under harsh marine environmental conditions is of great significance for the development and application of far-reaching marine solar energy. Based on practical engineering, a hexagon truss type floating photovoltaic platform is designed in this paper, which uses buoyancy block to provide buoyancy and adopts a 6 × 1 spread mooring system. The whole platform has the advantages of small waterplane, stable platform desirable motion response and small mooring tension. Firstly, an integrated numerical model of truss-buoyancy block and mooring system is established in commercial software OrcaFlex, subsequently the dynamic coupling calculation is carried out in the full-time domain, and the platform’s motion response and mooring tension characteristics under extreme sea conditions with high/low tide levels are investigated, respectively. The results show that the platform has excellent hydrodynamic performance as well as the tension on mooring chains is small, which can maintain stable operation under extreme sea conditions. The analysis and results can provide important reference for practical engineering.
The scale parameters of bubbles produced by underwater exhaust influence the effect of the acoustic insulation. According to the dynamic characteristics in the process of underwater exhaust and the design criteria of equal flow per unit area, the two-dimensional equation of underwater exhaust was established. The analytical expressions of the orifice position and geometric parameters of the two-dimensional underwater exhaust device were obtained. The finite element models were established to compare the two vent patterns of uniform distribution and fixed orifice spacing / variable orifice area distribution. The exhaust effect was verified by circulating flume test. The simulation and experimental results show that the fixed orifice spacing and variable orifice area distribution mode can effectively control the distribution of bubbles scale parameters, and enhance the acoustic insulation effect of bubbles.
To ensure the safety of transportation of heavy cargo by sea,it is necessary that the cargo be lashed and secured,in which the calculation of the inertial acceleration of the cargo is an important prerequisite for the strength analysis of lashing configurations.This paper,by taking a transport ship as the research object and using the hydrodynamic prediction method,obtains the inertial acceleration of the quay crane,and considers the wind load acting on the crane.It conducts finite element analysis of the lashing strength under typical working conditions.The calculation results show that the structural strength of the lashing configurations meet the requirements.The research method proposed this paper has a certain reference value for the lashing analysis of similar goods.
The deepwater semi-submersible production and storage platform undertakes the oil and gas development,storage,and transportation of Lingshui 17-2 Gas Field.The complex building structure inside the platform and the densely deployed electronic equipment increase the probability of emergencies such as fire and flooding,and increase the difficulty of evacuating platform operators and fire rescue.When an emergency occurs on the platform,the location of operators can be located to improve the rescue efficiency.Based on the ultra-low power consumption RSSI-based Bluetooth positioning algorithm,this paper designs an efficient and stable personnel positioning system for the above platforms.Through the visual interface,the central control system can realize realtime positioning of platform operators and the management of the personnel and platform.In case of an emergency,it can ensure the life safety of platform operators and improve the safe operation and maintenance of the platform.
This paper designs a kind of deepwater pipeline recovery tool（PRT）,including claws,the center structure,the hydraulic cylinder,the adjustable limitation thimble,integrated valve,and the remotely operated vehicle（ROV）hot stab.It also performs finite element analysis after structure design and hydraulic principle design.This equipment can be used to the recovery of submarine pipelines with different diameters,successfully solving the technical problems of deepwater submarine pipeline recovery,and promoting the development of equipment and technology in offshore oil engineering.
