工厂化对虾养殖池管式射流集污水力特性

工厂化养殖池内水体的流场分布特性直接决定了其对残饵、粪便等的排污性能。本实验研究了管式射流驱动模式下,射流角度与射流流速对养殖池内水体流场与污物聚集特性的影响。养殖池流场特性采用点式流速仪进行布点测量,利用MATLAB软件对流场特性进行分析。采用相机采集的养殖池集污效果图像,并利用Photoshop软件与自行开发的不规则图形面积分析软件对图像进行分析。研究表明,流速从池心向外呈"V"型变化,在射流角度固定的情况下,射流速度越大,池心低流速区域越小,污物向池心的聚集效果越好;在流速固定的情况下,存在一个最佳的射流角度,本实验在24 cm/s流速条件下,射流角度为40°时,池内污物聚集效果最优。结论认为在保证养殖对象生长的前提下,可尽量提高射流流速;在24 cm/s流速条件下,最佳射流角度在40°左右。本研究成果可为工厂化养鱼池、养虾池等管式射流水力驱动系统的优化设计提供参考依据。

Experimental study on the hydraulic characteristics of waste concen-trated in an industrial aquaculture pond equipped with a pipe jet flow system

Seawater factory farming is an important fisheries industry in China and a moderh,high-density,intensive farming model that is receiving increasing attention as it develops.Factory farming uses circulating water culture,in which water treatment technology is key.Timely removal of waste (bait,feces) from aquaculture tanks is an important means to improve water quality.In this study,the characteristics of the flow field and waste distribution in the pool were studied in a square circle cutaway model tank (mainly used for shrimp aquaculture),in which water flow was driven by a side-tube hydraulic jet to optimally conserve water and provide a reference for engineering factory farming pools.The flow field distribution is the main factor that directly affects the waste concentration in a recirculating aquaculture tank.We investigated the effects of jet flow velocity and angle on the flow field distribution and waste concentration characteristics in the tank.The flow field characteristics were measured with a point-type flow meter and were analyzed using MATLAB software.The waste distribution characteristics were obtained using self-developed image analyzing software.The original waste distribution images were captured with a high resolution camera.The results showed that flow velocity varied in a V type trend along the sections and through the center of the tank.Waste gathered more rapidly and at a higher concentration as jet velocity was increased at a fixed jet flow angle.The optimal jet angle was 40° when jet flow velocity was fixed at 24 cm/s.These results will be useful to optimize and design a hydraulic drive system for industrial fish or shrimp aquaculture tanks.The results suggest a jet angle of 40° with as high as possible jet flow velocity to ensure optimal animal growth.