Abstract:To measure the liquid film thickness containing hydrate in natural gas pipelines, an embedded concave electrical-acoustic compound sensor was designed based on the principle of electrical-acoustic joint detection method. A numerical simulation model was established to optimize the structure and working parameters of the sensor, and the liquid film thickness with discrete hydrate particles and hydrate deposition layers was measured by simulation. Finally the applicability of the resistance method and ultrasonic transit time method was discussed. The radius of the disk-shaped electrode and the distance between the disk-shaped electrode and the inner ring electrode are the major structural parameters that affect the spatial sensitivity of the electrical test. The ultrasonic frequency has a significant impact on the spatial sensitivity of the acoustic test. Therefore, it is necessary to optimize the parameters of the concave electrical-acoustic compound sensor. The resistance method and ultrasonic transit time method are suitable for measuring the liquid film with discrete particles and sedimentary layer, respectively. The advantages of the two methods are complementary to each other, thus the application range of the electrical-acoustic compound sensor is greatly widened.