Concept Design Of Large-scale Aquaculture Cage Platform And Single-Point Mooring System For Deep Sea

As a source of high-quality protein,fish demand has been steadily increasing in the past 50 years.China has vast marine resources,but with the increase of aquaculture,offshore aquaculture is becoming saturated,and the excessively dense aquaculture density has caused damage to the maritime,marine environment.In recent years,deep-sea aquaculture technology has developed rapidly,and new deep-sea aquaculture equipment such as Ocean Farm 1 and Havfarm designed by Norway has emerged.In China,there is a demand for new types of deep-sea aquaculture equipment.Emerging deep-sea aquaculture equipment abroad is mainly developed towards deep-sea,intelligence and large-scale.It is incredibly competitive in aquaculture and can bring substantial deep-sea strategic significance and economic value.This paper analyzes and summarizes the deep-sea aquaculture technology and new representative deep-sea aquaculture equipment abroad,and on this basis,proposes a single point mooring deep sea aquaculture cage platform concept.In this paper,a complete stability analysis of the designed single-point mooring deep-sea aquaculture platform,hydrodynamic and motion response analysis in the frequency domain,coupling analysis of floating body and mooring system in the time domain,etc.The main content includes the following aspects:1.Refer to the existing deep-sea aquaculture equipment program A single-point mooring ship-type deep-sea aquaculture cage platform is proposed,and its complete stability analysis is carried out.The designed deep-sea aquaculture cage platform can meet the corresponding technical requirements and has excellent stability.2.Use SESAM software to calculate and analyze the hydrodynamic response of the floating body in the frequency domain.The hydrodynamic calculation results of the Panel model and Composite model are analyzed and compared.The results show that the floating body has excellent hydrodynamic characteristics,and the motion response value is small in the degrees of freedom of heave,pitch,and roll,which are focused on.By comparing the difference in RAOs at different wave direction angles,it shows that the floating body motion response to the wave The angle is more sensitive;the comparison of the calculation results of the Panel model and the Composite model shows that the Morison model will have a significant impact on the hydrodynamics of the floating body.The damping of the viscous resistance to the motion of the floating body must be considered in the analysis and calculation of the deep-sea aquaculture cage platform.3.Analyzed the adaptability of the existing single-point mooring scheme and deep-sea aquaculture cage platform,based on which two types of deep-sea aquaculture cage platform single-point mooring schemes were designed.The time-domain coupling analysis was used to compare the different motion response of the floating body and the size of the mooring tension in the mooring mode and finally decided to use grouped single-point catenary mooring.Under all load case,the maximum mooring tension of the grouped mooring is less than equally spreading mooring.Among them,the maximum tension of the grouped mooring reaches 3758.51 k N,and the maximum tension of the equally spreading mooring reaches 3989.40 k N.4.Coupling analysis of the floating body and the mooring system in the time domain to analyze its motion response and mooring cable tension under the environmental load of the cold water mass in the Yellow Sea.The results show that the mooring system responds well to the motion of the floating body,and the tension of the mooring cable meets the requirements of the specification.With a mooring chain which minimum breaking load is 9335 k N,under a 100-year typhoon,,the maximum mooring tension is 9159.48 k N,and the minimum safety factor is 1.70,which is greater than 1.67 as required by rules.