New Thermal Mass Smart Gas Meter Development

With its simple structure,mature technology and stable performance,the orifice flowmeter occupies an important position in the process of gas metering angle connec-tion with the advantage that it does not require calibration before it can be put into use.However,the common orifice flowmeter on the market has the disadvantages of narrow measurement range,large pressure drop,measurement accuracy is affected by density,temperature and other factors,it is difficult to meet the requirements of the natural gas metering field.The thermal mass flowmeter has the advantages of small pressure drop and high accuracy,which has become an important development direction in the field of natural gas metering,but also has a small range,high maintenance costs and other shortcomings.This project is based on the orifice plate combined with the advantages of thermal mass flowmeter,design a class 2 accuracy,range of 0.01-48)~3/h,working life of more than 8 years,can accurately measure the gas flow of low-cost intelligent civil gas meter,reduce the natural gas metering system caused by the error of the measuring device.After researching for the gas flow meter,the overall design plan was determined,which includes measurement pipe structure design,hardware circuit design,software de-sign,simulation analysis and real flow calibration test,etc.The domestic GD32L233K8Q6is used as the main control chip to create an Io T and cloud-controlled natural gas metering management network through NB-Io T communication to achieve real-time monitoring,data transmission and remote control of the natural gas metering process.In addition,us-ing Solid Works simulation software,the device models of the standard orifice plate and multi-hole plate flowmeter,the effect of flow velocity disturbance are studied respectively through the calculation of fluid flow dynamics,and the design scheme is improved and optimised to improve the flowmeter metering accuracy.Finally,the smart gas meter pro-totype was tested in various aspects including thermal mass flow meter commissioning,cloud platform function testing,cumulative flow rate testing and working cycle power consumption measurement,etc.After calibration of the thermal mass flow meter and the prototype flow rate measurement error curve,the gas meter prototype was confirmed to be working normally and the performance indicators met the design requirements.The civil smart gas meter designed through this study can improve the accuracy and stability of natural gas metering,achieve more accurate and reliable natural gas metering,and at the same time establish a natural gas metering management network with Io T com-munication and cloud control,which can improve safety and management efficiency and contribute to the development of the natural gas industry.