The object of the dissertation research is the process of measuring the humidity of natural gas.
The purpose of the dissertation research is to increase the accuracy of gas humidity measurement based on the use of differences in the absorbing properties of the microwave traveling wave passing through dry natural gas and water vapor.
During the work on the dissertation the theory of electromagnetic field based on the technique of microwave wave propagation in gaseous media was used; measurement theory; theory of errors and processing of measurement results, methods of measuring the humidity of gaseous substances, physical and mathematical modeling; methods of mathematical statistics in the processing of results; methods of metrological certification and verification of non-standardized measuring instruments.
Theoretical results: improved mathematical model of radiation transfer in a wet gas environment, which adequately describes the physical processes and in which, in contrast to the known, the density of wet gas in the general case is represented as the sum of densities of dry natural gas and water vapor at their partial pressures and temperatures taking into account the absorption of natural dry gas and water vapor. The method of measuring the humidity of natural gas in the microwave region, which, unlike the known ones, differs in that the values of gas humidity are obtained on the basis of the ratio of natural dry gas and water vapor absorption as a result of using a "running" microwave wave of a certain length. the ability to increase the accuracy and high convergence of measurement results and offer single-channel and two-channel measuring transducers for its implementation. For the first time, a mathematical model of a microwave moisture transducer based on a traveling wave was proposed, and on its basis the transformation equation of a two-channel measuring transducer was obtained. It is proved that when using a two-channel scheme, the multiplicative error that occurs in the process of instability of the microwave signal source, frequency deviation and natural losses of waveguides is reduced by 1.3-1.5 times. The mathematical model of the microwave humidity measuring instrument was further developed, which made it possible to obtain the transformation equation, which unambiguously connects the initial value - the power value of a certain wavelength of the microwave generator and the input - the value of absolute humidity, which allowed to obtain static humidity with stable metrological and operational characteristics. It is experimentally proven that the tools that implement this method are characterized by a low measurement error of 2.5%. The practical results of the obtained results are the development and implementation of an experimental sample of a microwave humidity measuring instrument, characterized in that the absorption properties of certain wavelengths for both dry gas and water vapor as a result of passing through a gaseous medium are taken into account. As a result of metrological researches of experimental means the possibility of measurement of humidity in the range of temperature of a dew point (so-called) - 30o C… +30 oC that corresponds to value of absolute humidity of 0, 454 g / m3… ..30,37 g / m3, the maximum aggregate error of the humidity measuring instrument does not exceed 2.43%, and the accuracy class is 2.5. A method of experimental determination of natural dry gas and water vapor absorption indices, as well as experimental choice of radiation wavelength for both dry gas and water vapor has been developed. A method for designing a microwave instrument for measuring the humidity of natural gas has been developed, which consists of three main parts: a primary measuring transducer, a signal processing unit and an automatic measurement algorithm.
The obtained results are implemented in the form of an experimental sample of microwave humidity measuring device, separate results of dissertation work in AT "Kharkivgas" are developed and implemented, in particular, the method of calculation of water vapor and dry gas absorption coefficients, as well as temperature correction, and in the educational process of the Department of Electronics and Nanosystems of Vinnytsia National Technical University.
