淡水珍珠蚌循环水养殖模式下分布式水质监控系统设计

为促进中国淡水珍珠养殖业由传统粗放模式向高效生态智能化改造升级,该研究针对珍珠蚌工厂化循环水养殖模式下的水质监控需求,开发了基于无线传感网络的分布式水质监控系统。系统采用感知层、传输层和应用层相结合的体系架构,由水质监测节点、气象监测节点、设备控制节点和监控中心组成。现场采用多参数传感器、ZigBee无线模块、可编程逻辑控制器(Programmable Logic Controller,PLC)和MCGS触控屏组合的方式,实现对多地点监测数据的实时采集、图形化显示和报警功能,对循环水处理设备的启停控制及藻类供饵自动控制功能;上位机采用MCGS网络版和SQL Server数据库构建监控数据中心。系统采用无线组网分布式架构,组网灵活且操作简单,简化了设备的安装和维护工作。经实际使用测试,系统工作稳定性和检测准确性均在98%以上,能够满足淡水珍珠蚌循环水养殖的监控需求,可以为珍珠蚌传统养殖模式的转变和产业生产方式的转型升级提供有利保障。

Design of distributed water quality monitoring system under circulating water aquaculture mode of freshwater pearl mussels

In China,the freshwater pearl mussel aquaculture plays an important role in agricultural production.The freshwater pearl mussel’s growth process does not harm the environment,but the traditional aquaculture model has caused problems such as serious water pollution,eutrophication,and ecological environment destruction.Facing such a situation,it’s necessary to develop a new model for freshwater pearl aquaculture.This study showed a new industrialized circulating water aquaculture model(using multi-layer dimensional cages and feed pearl mussel with high-quality microalgae).Due to the high density of aquaculture,this model had very high requirements for water quality,so it was particularly important to monitor the circulating water quality.This study developed a distributed monitoring system for the water quality monitoring based on ZigBee wireless sensor network.The system used the three-layer architecture of the field sensing layer,transmission layer and application layer,and mainly included the following 4 parts:water quality monitoring subsystem,meteorological monitoring subsystem,equipment control subsystem,and monitoring data center.The system used the ZigBee module to set up the wireless transmission network,the advantage of this method was flexible networking and easy operation,and it simplified the installation and maintenance work.In the field scene,we set up multiple monitoring points in different places,multi-parameter water quality sensors were used to monitor key circulating water quality parameters(including temperature,pH value,dissolved oxygen,ammonia nitrogen,calcium concentration,and algae concentration),and meteorological parameters(such as temperature,humidity,barometric pressure,illumination,wind direction,and wind speed)were collected at meteorological station.All the sensors sent real-time detection data to their related ZigBee routers by RS485 protocol,and through the ZigBee wireless communication network,the data(including water quality and meteorological parameters)would be gathered in the ZigBee coordinator.The ZigBee coordinator was the center of the wireless communication network,it was also connected to the PLC controller by RS485 protocol,so the PLC controller could collect real-time detection data from basic monitoring points.At the same time,the PLC controller and MCGS touch screen communicated through the serial port,so the water quality and meteorological parameters monitoring information could be displayed on the MCGS touch screen.According to the designed procedure,the MCGS touch screen displayed the water quality data change curve,and users could also issue equipment control commands at the screen,such as controlling the circulating water treatment equipment(including arc screen separator,microfiltration filter,protein separator,sand filter,and disinfection pool)and the algae feeding system device.By using the PLC controller,the study designed a program to control the start and stop status of aquaculture equipment and adopted a two-position control strategy for the algae feeding system.Besides,the PLC controller communicated with the host computer via the CP243-1 Ethernet communication module,so all the monitoring data was uploaded to the host computer in the monitoring center house.On the host computer,MCGS(network version)software and SQL Server database software were used to build a database to save the water quality data,and this database could provide a decision basis for scientific aquaculture.Through the practical test,the communication success rate of the whole system was more than 98%,and the average relative errors of dissolved oxygen,temperature,pH,and ammonia nitrogen were±0.3 mg/L,±0.4℃,±0.3 and±0.04 mg/L,respectively.It could be seen that this system met the monitoring needs of freshwater pearl mussel aquaculture.This system was conducive to solve the previous shortcomings and ensure the growth of production,it was very worthy of promotion and application,and it would open up a new situation for the establishment of a new environment-friendly and efficient aquaculture mode of freshwater pearl mussel.