Gas turbine flow meter has the advantages of high sensitivity, good repeatability, wide range ratio and high precision. It has been widely used in natural gas natural gas custody transfer and process measurement and even as a standard instrument for quantity transfer. With the full development of China's urban gas engineering and the continuous improvement of gas commercial trade and handover measurement requirements, gas turbine flow meters
have gradually become one of the preferred instruments for commercial gas trading and handover measurement in China.
The turbine flow meter is a speed flow meter that uses gas to drive the impeller of the flow meter. The speed of rotation of the impeller is proportional to the volumetric flow of the fluid. According to the principle of electromagnetic induction, the magnetic sensor is used to induce the volume of the fluid from the synchronously rotating impeller. The pulse signal proportional to the flow rate is processed to obtain the volume flow rate. The measurement accuracy is high, the accuracy level can reach 1.0 level, 1.5 level; the range ratio is wide, generally 1:20 measurement range is wide; the structure is compact and light, the installation and maintenance are convenient, the requirements of the straight pipe section are low, and can be used for medium and high pressure measurement.
Turbine flow meters also have the following disadvantages: there are movable parts, which are easy to damage, the bearing of the key parts is easy to wear, the dirt resistance is poor, the cleaning degree of the medium is high, and it is difficult to maintain the calibration characteristics for a long time, and regular calibration is required. The causes of the error are: the quality of the meter itself, the design selection is unreasonable, the installation is not in place, and the maintenance during operation is improper.
How to control the error? Correctly determine the location and specifications of the flow meter. Due to the inertia of the turbine flow meter turbine, it is not suitable to use in the case of frequent flow fluctuations; otherwise the measurement accuracy will be reduced. To accurately estimate the peak-to-valley value of the gas volume and the pressure of the medium, the flow meter specifications are correctly determined.
The filter must be installed before the gas turbine flow meter; the filter should be kept clean. If the filter is found to be clogged (can be judged by the pressure difference between the filter inlet and outlet), the filter should be cleaned in time, if not equipped with a differential pressure gauge, please Clean the gas meter once a month. To ensure the requirements of the straight pipe section, especially in the case of a reduced diameter or a half open valve in front of the table. During installation, the gasket shall not protrude into the pipeline, and the flow meter and the pipeline axis shall not be visually inspected and shall not cause installation stress. Always clean all impurities in the pipe during installation to prevent the bearing and turbine from getting stuck.