Objective Experimental and mathematical fitting methods are used to develop a new approach for converting water content to dew point in natural gas to enhance conversion accuracy and reduce errors.
Methods This paper adopts the combined application of gas standard substances, portable dew point mirrors, and Matlab mathematical software. Using cubic spline interpolation technique, it establishes a novel method for converting water content to water dew point.
Results By utilizing surface fitting for the conversion of water dew point, this method achieves a Mean Absolute Error (MAE) of 1.16 ℃ and a Root Mean Square Error (RMSE) of 2.28 ℃, meeting the reasonably acceptable maximum deviation of 2.8 ℃. By comparing this method with the domestic and international mainstream conversion methods, the average absolute deviation of the three methods are 0.46% (cubic spline interpolation), 0.69% (GB/T 22634-2008 Conversion between water content and water dew point of natural gas), and 0.84% (ASTM D1142-95(2021) Standard test method for water vapor content of gaseous fuels by measurement of dew-point temperature), respectively, and the applicability of the three methods under different water content and pressure ranges is analyzed and explored.
Conclusions Through comparative studies with experimental values, the cubic spline interpolation method shows better conversion accuracy for water volume fractions from 0 to 200×10-6 compared to standard methods, effectively reducing the conversion error between water content and water dew point.
DownLoad: