污水管道水位流速检测装置设计

Design of water level and flow rate detection device for sewage pipeline

在线实时监测市政污水管道内污水的水位和流速能帮助市政管理部门精准掌握污水流动情况,及时了解管道出现的问题,提高工作效率。该文依据绕流理论设计并制作了一种基于浮球的水位和流速检测装置,通过测量浮球随水位变化的相对位移实现水位测量;通过测量流体对浮球的推力实现流速测量。装置的GSM/GPRS模块接收水位和流速的检测数据并传输至远程监控端,实现远程在线监测。在明渠标准实验台对该检测装置的水位和流速测量值进行标定和精度实验,实验结果表明:测量水位的偏差在±3 mm内,误差不大于其满量程的0.5%;流速测量偏差值在±0.04m/s内,误差不大于其满量程的5%。将该检测装置安装在实际的污水管道内,对污水水位和流速进行了为期三个月的实验监测,检测值的远程传输结果符合预期。

[Objective]The online real-time monitoring of water levels and flow rates in municipal sewage pipelines is crucial.It provides municipal workers with immediate insights into the operational conditions of these pipelines,enabling timely responses to any issues.However,current market offerings capable of simultaneous water level and flow rate detection are often prohibitive owing to their cost or complexity,limiting large-scale deployment.This highlights the need for an economically viable,real-time online device to monitor water levels and flow rates.In response to this need,we have designed a new device that measures both water levels and velocities using floating balls,all based on fluid flow theory.[Methods]In our study,we designed and manufactured a detection device based on flow field theory.The device measures water levels by tracking the distance between a fixed box and a hollow,stainless steel ball that floats on the water surface.A rod connects the ball and the measuring box,allowing us to determine water level changes by measuring the float ball’s relative displacement.Flow velocity detection,alternatively,is indirect.We use a force sensor to measure the force exerted by the water flow on the floating ball.This force is transmitted and amplified by the lever mechanism of the rod.The flow velocity is then determined by sensing the thrust of the flow water on the floating ball.To prevent the floating ball from capturing debris,which could destabilize the flow and affect the measurements,we added a conical tail end to the floating ball,transforming it into a tail cone-tipped floating ball.The fish-like design of the floating device,featuring a large round head and a smaller cone tail,enhances its stability in water.The design of the measurement box encompasses hardware and software.The hardware of the detection system includes a microcontroller module,an A/D conversion module,and a display and remote data transmission module.The system receives water level and flow rate data through the device’s GSM/GPRS module and transmits it to a remote monitoring endpoint,enabling remote online monitoring.We calibrated the water level and flow velocity measurement values of the detection device using experiments conducted on an open channel standard experimental platform.We then installed the device in an actual underground sewage pipeline for a 3-month on-site experimental monitoring of the sewage water level and flow velocity.[Results]The experimental results exhibit the following:①The improved floating device,equipped with a tail cone,is resilient to debris accumulation.This stability ensures the accuracy of the water level measurement process.②The deviation in measuring water level is within 3 mm,and the error does not exceed 0.5%of its full scale.The deviation value of flow rate measurement falls within±0.04 m/s,and the error remains below 5%of its full scale.③Our onsite experimental monitoring results indicate that the detection device works normally.The monitored changes in water level and flow rate are consistent with the actual conditions,proving the measurements to be accurate enough for pipeline water flow condition monitoring.[Conclusions]The developed sewage pipeline water level and flow rate detection device offers several advantages.With its simple structure,low cost,and resistance to debris accumulation,it is an easy-to-install solution that can deliver remote data transmission.These issues make it well-suited for application across the entire sewage pipeline network.