The working principle of the impeller type flowmeter is that the impeller is placed in the fluid to be measured, and is rotated by the impact of the fluid flow, and the flow rate is reflected by the speed of the impeller rotation. Typical impeller flow meters are water meters and turbine flow meters, which may be of mechanical transmission output or electrical pulse output. Generally, the water meter output of the mechanical transmission has low accuracy and the error is about ±2%, but the structure is simple and the cost is low. The domestic production has been mass-produced, standardized, generalized and serialized. The accuracy of the turbine flowmeter for electrical pulse signal output is high, with a typical error of ±0.2% to 0.5%.
Differential pressure flowmeter (variable pressure drop flowmeter)
The differential pressure flowmeter consists of a primary device and a secondary device. The primary device is called a flow measuring element and is installed in the pipe of the fluid to be measured, generating a pressure difference proportional to the flow rate (flow rate) for the secondary device to display the flow rate. The secondary device is called a display instrument. It receives the differential pressure signal generated by the measuring component and converts it to the corresponding flow for display. The primary device of the differential pressure flow meter is often a throttling device or a dynamic pressure measuring device (piteron, constant velocity tube, etc.). The secondary device is equipped with various mechanical, electronic and combined differential pressure gauges with flow display instruments. The differential pressure sensitive components of the differential pressure gauge are mostly elastic components. Since the differential pressure and the flow rate are in a square root relationship, the flow display instrument is equipped with an open square device to linearize the flow scale. Most meters also have a flow accumulator to display cumulative flow for economic accounting. This method of measuring flow using differential pressure has a long history and is relatively mature. Generally, countries all over the world use it in more important occasions, accounting for about 70% of various flow measurement methods. The flow measurement of the main steam, feed water, condensate, etc. of the power plant is based on this meter.
Gas turbine flowmeter and screwing vortex flowmeter measurement difference
Keywords: gas turbine flowmeter, Tianxin gas turbine flowmeter, gas gas turbine flowmeter
The gas turbine flowmeter has good repeatability and is the preferred flow meter for trade settlement. The gas swirling vortex flowmeter is generally repeatable.
The gas turbine flowmeter can obtain very high frequency signals with strong signal resolution. The frequency of the gas swirling vortex flowmeter is very low, and the smaller the diameter, the lower the signal resolution. The measurement error is to be measured.
The gas turbine flowmeter has a wide range, generally 40:1~20:1, and has a wide measuring range, which can be suitable for occasions with large flow changes. When natural gas is delivered, the flow changes are generally large and, therefore, are particularly suitable for natural gas measurements. The latter range is medium, generally 15:1 to 10:1, and the measurement range is slightly narrower. When measuring gas, it is more suitable for occasions where the flow rate does not change much.
In terms of seismic performance, gas turbine flowmeters have better resistance to pipeline vibration. The gas swirling vortex flowmeter is susceptible to pipeline vibration and should be taken care of when using it.
Turbine flow meter applications
Turbine flow meters are widely used in the following measurement objects: petroleum, organic liquids, inorganic liquids, liquefied gases, natural gas, gas and cryogenic fluids. In the transshipment and gathering stations of foreign liquefied petroleum gas, refined oil and light crude oil, the first and last stations of large crude oil transmission pipelines use it for trade settlement. In Europe and the United States, the turbine flowmeter is the natural gas meter next to the orifice flowmeter. In the Netherlands alone, more than 2,600 gas turbine flowmeters of various sizes and pressures from 0.8 MPa to 6.5 MPa are used on the natural gas pipeline. Has become an excellent natural gas flow meter. Although the excellent metering characteristics of the turbine flow meter are favored by people, the impression is that the moving parts are short in use time, and they are inevitable in the selection. After people's unremitting efforts, it should be said that the situation has changed a lot. As the most versatile flowmeter, the turbine flowmeter has been developed into a multi-variety, full-series, multi-size mass production scale.