Ultrasonic Flowmeter Structure Design Based On Structure And Flow Field Analysis

Ultrasonic gas flowmeter for its high accuracy, low pressure loss, wide measurement range and convenience of maintenance, etc., are widely used in gas pipeline network, city gas gate stations and gas storage and distribution station and other occasions. Currently, the domestic market of ultrasonic gas flowmeter is basically monopolized by foreign brands, independent research and development has important significance.Difficulties in the development and application of ultrasonic gas flowmeter include signal processing, sensor research and development, flow field compensation and security. This paper focuses on the impact of the ultrasonic flowmeter’s shell structure (basic meter structure and secondary instrument’s shell) to metering performance and safety performance. And relevant content was tested by experiments. The main contents are as follows:1, in ultrasonic gas flow meter’s basic meter structure’s design, the ultrasonic transducer installation can influence the measurement accuracy. Ultrasonic gas flow meter’s measurement accuracy is greatly impacted by the state of the flow field, and the ultrasonic transducer mounted in the pipe can cause bumps or depressions structures, resulting in a negligible impact on the measured flow field. This paper studies the impacts cased by three types of transducer installation (recess installation, protrusion installation and half protrusion), and finally determine the optimal transducer installation.2, the study of the temperature sensor’s installation in the ultrasonic gas flow meter. This paper calculates the affected area caused by the temperature sensor’s installation through simulation, and determines the installation position of the temperature sensor.3, the research on the demand of pipe wall roughness in the ultrasonic gas flowmeter. Pipe wall roughness also affects the flow field and may cause additional error. This paper studies the measurement error results from different wall roughness by compared with the ideal smooth wall, and determines the ultrasonic gas flowmeter’s requirement on pipe wall roughness.4, the design of the shell of ultrasonic gas flowmeter’s secondary instrument. Because the ultrasonic gas flowmeter works in explosive environment, its secondary instrument must get extra protection, so that it won’t cause explosion even it generates sparks or overheated. In this paper, the ultrasonic gas flowmeter’s secondary instrument flameproof shell has been designed and its effect of flameproof is verified by simulation and experiment.