Development of Mathematical Model of Two-channel Microwave Measuring Converter of the Humidity of Natural Gas

Abstract

The choice of the waveguide microwave method of measuring the humidity of natural gas has been substantiated in the article. In contrast to the known methods, the use of a traveling wave in a waveguide has been proposed, and changes in the dielectric properties of gases when they interact with the microwave waves in the microwave range are estimated.

A mathematical model for the microwave measuring converter of the humidity of natural gas has been proposed, the meaning of which is to absorb the microwave signal and, consequently, measure the power of this signal at the output of the waveguide when the humidity of the gas changes by using a traveling wave. The function of conversion and theoretical dependence, which indicates high sensitivity, has been obtained. The dependence of the power of a traveling wave on the absolute humidity of water vapor at various values of the passage of the microwave signal in a humid environment, taking into account temperature and pressure has been investigated.

Based on the research, a two-channel microwave measuring transducer of natural gas and its mathematical model has been proposed. The model takes into account the dielectric constant of the measuring and reference channels, and the temperature and pressure of the natural gas of the measuring channel.

There have been conducted the studies that showed that the presence of the reference channel has improved the measurement accuracy, since the two-channel system, in contrast to the single-channel, eliminates the instability of the value of the input signal supplied by the generator.

The principle of operation of a two-channel microwave measuring transducer of natural gas has been described, which contains a microwave generator, attenuator, waveguide tee, waveguide comparison section, temperature and pressure sensor, reference channel switch, measuring cell, amplifier, display. The research results suggest that it is promising for practical application of measuring the humidity of natural gas devises using tools based on the microwave traveling wave method.