The Research On Environmental Suitability Of Ultrasonic Gas Meter

With the improvement of urban gas market,the Ultrasonic gas meter goes from early concentration major projects to end users.The condition of end users have big different with concentration users,the differences mainly embodies addresses spread out,no full-time maintenance man;the flow is small and frequent change;long life period and no calibration in life period;users are sensitive to the economy of gas consumption and have high requirements for measuring accuracy.Study on environmental suitability of ultrasonic gas meter not only can explicit the influence of different interference sources on the measurement accuracy of UGM,but also have very important significance for improving the accuracy for its measurement and reducing the economic disputes between the gas enterprises and the users.This paper studied the environmental adaptability of a certain type of ultrasonic gas meter,analysis the principle of measurement and the influence of measurement signal on measurement accuracy;set up an experimental platform to test the metering error of same type ultrasonic gas meter when measuring air and natural gas;analysis the relation of meter error and the different gas composition;by adding different types of impurity particles of ink powder,lime powder and rust iron dust in the process of test measure error analysis the influence of these impurities;and in virtue of software fluent CFD studied the flow field distribution in the lower bend,the purpose is to reasonably determine the working environment of the ultrasonic gas meter,and put forward some measures to improve the metering performance.The results of the study show that:ultrasonic signals have different propagation paths in the tube in the forward and reverse flow directions,and their propagation paths have sine and cosine waveform characteristics,this feature will reduce the signal reception quality.The composition of the metered gas will affect the revised standard metering value,and in particular,the actual amount of methane in the metered gas is negatively correlated with the standard correction value of the metering value.At the same time,when the metering gas is air,the measurement accuracy of adding the toner to the added impurity particles is higher in the large flow range than in the added iron dust,and vice versa in the small flow range.in terms of air,rust-iron dust compared to toner will cause greater errors in the measurement results of ultrasonic gas meter measure q_t-q_max.when the metering gas is natural gas,the effect of the addition of toner on the measurement results of the ultrasonic gas meter is similar to that of rust iron dust,that is,in the q_min-q_t range,the error rate of adding toner is larger than that of iron dust,in contrast to the q_t-q_max range.Lastly,in the impurity particles added during the experimental test,the toner with small particle size and light density had the strongest adsorption to gas meters,followed by lime powder,and the adsorption of rust iron dust was the least obvious.