| China has the vast marine area and many islands,where conventional energy is scarce.It is of great significance to develop and utilize clean energy for desalination of seawater to meet the needs of people’s life and production.The energy conversion equipment is the key of marine energy equipment.In this paper,a tidal-powered radial seawater pump was developed,which was directly connected to the turbine without intermediate energy conversion and transmission.In addition,due to the low viscosity and leak ability of seawater medium,a hierarchical sinusoidal surface morphology structure was proposed based on the micro-structural characteristics of natural materials,and its leak reduction performance was studied.The main contents of this paper include:(1)According to the characteristics of seawater and working conditions of seawater pump,the key technology and difficulties of seawater pump design were clarified,and the structure of seawater pump was designed.The body type of pump,which could connect with the turbine and bidirectional work was obtained.The guide curve of the moving shell of the seawater pump was designed and obtained.The material used for the friction pairs of the seawater pump was determined.(2)The movement law of seawater pump and the stress of key components were studied.The parameters of the length of piston stay in the cylinder,the force between the piston and the cylinder,the deformation of the cylinder bore bushing were studied.The contact stress between the piston rolling body and the guide rail surface was analyzed by using Hertz contact theory.The dynamic relationship between the contact stress of the piston rolling body and the guide rail surface was obtained.(3)Processed the seawater pump and built the experimental rig to test the performance of seawater pump.The performance curves of seawater pump were obtained.In addition,the leakage reason of of seawater pump was analyzed.Effects of clearance size,eccentricity,length of piston stay in cylinder and movement speed of piston on leakage are further analyzed,and their dynamic relationship were obtained.(4)Proposed a gap model with hierarchical sinusoidal surface morphology structure based on the surface morphology characteristics of natural bio-materials.The experimental study was carried out.The zero-order model,first-order sinusoidal surface topography model and second-order sinusoidal surface topography model were designed.The samples were processed by 3D printing technology,and the gap flow rate was measured experimentally.The results show that the gap flow of the second-order sinusoidal surface topography model is less than that of the zero-order and the first-order sinusoidal surface topography model,which proves that the introduction of the second-order sinusoidal surface topography can effectively reduce leakage.(5)Studied the reduction performance of the hierarchical sinusoidal surface topography with different geometric parameters by Fluent numerical simulation.Analyzed its leakage reduction mechanism.Obtained the influence of morphological characteristics of hierarchical sinusoidal structure on the leakage.Compared the reduce leakage performance of hierarchical sinusoidal surface morphology model proposed in this paper with the surface morphology model in the literature.The results show that the hierarchical sinusoidal surface morphology model has good performance of reduce leakage. |
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