Working Principle of Turbine Flowmeter and Its Design and Application in Oil Pipeline

Oil pipelines are extremely important transmission equipment in the modern energy industry. The requirements for fluid measurement in oil pipelines are the goal that relevant technicians have been pursuing, and it is also a technical problem that will never end. After all, the pursuit of technology in industrial production is endless. With the rapid progress of science and technology, this problem has been solved more and more perfectly. In view of this situation, through this article, the author combines the work practice of the unit to communicate with you about the design problems of turbine flowmeters in oil pipelines.

1. Working principle of turbine flowmeter

The working principle of the turbine flowmeter is to install a turbine in the pipeline, supported by bearings on both sides. When the fluid passes through the pipeline, it impacts the blades of the turbine, and the impact force generates a driving torque on the turbine, causing the turbine to overcome the friction torque and rotate. Within a certain flow range and for a certain fluid medium viscosity, the turbine's rotational angular velocity is proportional to the fluid flow rate. Therefore, the fluid flow rate can be obtained through the turbine's rotational angular velocity, and the fluid flow through the pipeline can be calculated.

The speed of the turbine is detected by the sensor coil installed outside the casing. When the turbine blades cut the magnetic lines of force generated by the *magnetic steel in the casing, it will cause the magnetic flux in the sensor coil to change. The sensor coil sends the detected magnetic flux periodic change signal to the preamplifier, which amplifies and shapes the signal to generate a pulse signal proportional to the flow rate, which is sent to the unit conversion and flow accumulation circuit to obtain and display the cumulative flow value; at the same time, the pulse signal is also sent to the frequency current conversion circuit to convert the pulse signal into an analog current, thereby indicating the instantaneous flow value.

2. Design and application of turbine flowmeter in oil pipeline

1. Main performance of turbine flowmeter

Rated pressure: 4 MPa; Length: 600 mm; Flow range: 50 to 250 cubic meters per hour; Pressure drop: less than 40 kPa at maximum flow (when water is used as the test medium); Total mass: less than 40 kg. It can work normally in an environment of -41 degrees Celsius to +46 degrees Celsius. The meter head displays instantaneous flow and cumulative flow at the same time, and can switch to display total cumulative flow, batch cumulative amount, instantaneous flow and medium temperature. The reading is convenient, clear and intuitive.

The communication interface is equipped with a transmission distance of no less than 900 meters. The instrument coefficient is corrected by multiple nonlinear corrections. The instrument coefficient of the flow meter is calculated by interpolation according to the instrument coefficient corresponding to different flow points. Temperature compensation function: The reference temperature is 20 degrees Celsius, and different oil products are compensated by different temperature volume coefficients.

Measuring accuracy: zero point level 2.