Effect of Calculation Algorithms on Accuracy of Gas Flow Measurement Result at Low Temperatures

The article is devoted to the problem of ensuring the accuracy of measuring the flow rate of natural gas at temperatures below 250 K. To determine the amount of gas corrected to standard conditions, special algorithms based on state equations are used. One of the parameters included in the equation of state is the gas compressibility factor, which is reliably determined for temperatures above 250 K. The article considers the main algorithms for determining the natural gas compressibility factor at temperatures below 250 K, used in practice gas metering units. It has been shown that when using the substitution values of T and Z, a significant additional systematic error occurs. A numerical estimate of the values of this error is given. According to the results of the study, this additional error is systematic, increases with a decrease in temperature and leads to an underestimation of the amount of natural gas corrected to standard conditions. The key methods of the study presented in this paper are comparative analysis and numerical experiment.