Research On The Water Content Measurement Method Based On Microwave Transmission Method

Microwave method is a non-invasive,fast,and accurate method for measuring water content,widely used in the petroleum industry and environmental protection fields.This method is based on the different dielectric constants of crude oil and water,and utilizes the absorption and reflection characteristics of microwave propagation in the material.By measuring the transmission loss of microwave in the oil-water mixture,the water content in the oil-water mixture is inferred.In this paper,based on the study of microwave transmission theory,a set of oil-water mixture water content measurement system is designed.Firstly,the basic principle of microwave transmission method is simulated for the attenuation of different water content of oil-water mixture containing at different frequency points,and combined with the diameter of the oil pipe used in the oil-water mixture water content measurement system and the limitation of the frequency of the oil-water mixture water content measurement instrument used in the system,finally,the best measurement frequency of the system is determined at 2.45GHz.Then,the microwave transmission method oil-water mixture water content measurement system is analyzed at this frequency.The water content of mixed liquids measurement system,due to the design of small size antenna is the key component of the microwave transmission method water content measurement system,that is,the requirement of the antenna radiation aperture surface less than 50.30mm pipe diameter of small size antenna.To solve this problem,a half-cut antenna with an operating frequency band of 2～6 GHz,an in-band reflection curve of S11-10 d B,and a radiation aperture surface of 17×45 mm~2 was proposed.Finally,a microwave transmission method water content test environment is built,and the relationship curve between microwave transmission method water content and transmission coefficient is derived.The simulation results show that the simulation measurement of microwave transmission method water content satisfies the experimental error requirement when the water content of microwave transmission method is varied in the common range.In order to facilitate the extension of the experiment,the experimental analysis of crude oil water content by microwave transmission method was carried out on the circuit measurement system,and the experimental error analysis of the measured results was carried out.