摘要
为探究圆形循环水养殖池进水管布设位置对池内的流场分布以及残饵粪便等固体颗粒物排出的影响。该研究基于计算流体动力学(Computational Fluid Dynamics,CFD)技术,采用STAR-CCM+软件系统地模拟进水管在常见布设角度(θ=0°、45°),不同布设位置(d=0、1/8 r、1/4 r、3/8 r、1/2 r,d为射流管与池壁的距离,r为养殖池半径)工况下,养殖池内的流场分布特性和固体颗粒物的运动特性,并以固体颗粒物的排出率为主要性能指标,对进水管布设位置进行优化分析。监测了距离池底2、16.5、31 cm(底层、中层、顶层)水层的流场分布特性并利用固-液-气三相流模型详细地模拟了固体颗粒物在养殖池内的运动和汇集过程。结果表明:在水力停留时间为20 min下,进水管设置位置明显影响固体颗粒物的排出率,θ=0°时,当布设距离设置为d=0时,固体颗粒物的排出率最低,其余布设距离工况下,排出率均较高(>90%)且相差不大,在d=3/8 r时取得最大值95.0%;θ=45°时,当布设距离设置为d=1/2 r时,固体颗粒物的排出率最低,其余布设距离工况下,排出率均较高(>90%)且相差不大,在d=0时取得最大值94.3%。因此当进水管布设角度θ=0°时,建议不要贴近养殖池边壁;当进水管布设角度θ=45°时,建议距离养殖池边壁不要超过半径的1/2。研究结果可为优化工厂化圆形循环水养殖池的进水管布设距离提供参考,提升循环水养殖的综合性能。
An industrialized Recirculation Aquaculture System(RAS)has been widely used in an efficient,intensive,and environment-friendly way for modern aquaculture.A large amount of feed needs to be added to the system during the breeding process.Some solid residuals can be easily deposited at the bottom of the breeding pond,such as the uneaten feed and feces produced by fish.These residuals can then be decomposed and produce harmful substances to pollute the water body,while consuming the dissolved oxygen,if they cannot be discharged in time.As such,a great threat has been posed to the health of fish.Therefore,it is very necessary to effectively and timely remove these solid particles in the RAS tank.In this study,a solid-liquid-gas three-phase flow model was constructed to optimize the layout of inlet pipes in a RAS tank using Computational Fluid Dynamics(CFD)technology.A STAR-CCM+software was also selected to systematically simulate the common layout angle of inlet pipe(θ=0°and 45°,θwas the deployment angle of inlet pipe),under different layout positions(d=0,1/8r,1/4r,3/8r,and 1/2r,d was the distance between the jet pipe and the tank wall,r is the radius of the aquaculture tank).The error of cumulative removal efficiency at each monitoring time was less than 5 percentage point,indicating a high calculation accuracy in the numerical simulation,compared with the experimental.A systematic investigation was made to explore the layout influence of water inlet pipes in the circular RAS tank on the flow field distribution in the tank,as well as the removal efficiency of solid particles.The results show that the position of inlet pipes outstandingly determined the removal efficiency of solid particles.The lowest removal efficiency of solid particles was obtained,when the layout distance was set to be d=0 andθ=0°under the rapid circulation(low hydraulic retention time).Furthermore,the removal efficiency was much higher(>90%)with small difference in the rest of the layout distance.Consequently,the maximum removal efficienci
作者
胡佳俊
朱放
姚榕
桂福坤
刘博
张泽坤
冯德军
Hu Jiajun;Zhu Fang;Yao Rong;Gui Fukun;Liu Bo;Zhang Zekun;Feng Dejun(National Engineering Research Center for Marine Aquaculture,Zhejiang Ocean University,Zhoushan 316022,China;School of Naval Architecture and Maritime,Zhejiang Ocean University,Zhoushan 316022,China;School of Fisheries,Zhejiang Ocean University,Zhoushan 316022,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2021年第21期244-251,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(31902425)
浙江省自然科学基金项目(LGN21C190010)
舟山市科技项目(2020C21003)
国家级大学生创新创业训练项目(202010340011)。
关键词
养殖
颗粒物
固-液-气三相流模型
排出率
圆形养殖池
aquaculture
particles
solid-liquid-gas three-phase flow model
removal efficiency
circular recirculating aquaculture tank
