Several problems of solutions
Recalculating the differential pressure scale
Temperature and pressure compensation can only reduce the measurement error, not only can not solve the problem fundamentally, but also the measurement signal exceeds 20mA, resulting in steam leakage measurement. The transmitter measurement signal exceeds 20 mA, indicating that the actual measured differential pressure signal ΔP exceeds the design differential pressure value.
Increase temperature and pressure compensation
When the temperature and pressure of the steam change, the density of the steam changes, and the steam flow measurement produces an error. Measurement error can be reduced by temperature and pressure compensation. Since the temperature of the saturated steam is a single-valued function of the pressure, the temperature and pressure compensation of the saturated steam can be pressure compensated or temperature compensated. Because the pressure signal detection is sensitive and the compensation accuracy is high, it is compensated by pressure and realized by DCS.
Conclusion
Steam is a special medium. As the pressure and temperature change, the density of steam changes. Therefore, it is necessary to compensate for temperature and pressure. When the pressure and temperature fluctuation of the steam are not large, that is, when the operating condition parameters deviate from the design parameters and the influence on the measurement is small, the temperature and pressure compensation measures can achieve the purpose of accurate measurement. However, when the operating parameters deviate too much from the design parameters or the operating parameters fluctuate frequently and are too large, even with the temperature and pressure compensation, it is difficult to meet the measurement accuracy requirements. At this point, only differential pressure or flow can be recalculated for a particular throttling element.
Precautions before gas turbine flowmeter is enabled
Keywords: gas turbine flowmeter, Tianxin gas turbine flowmeter, gas gas turbine flowmeter
First, the precautions before the gas turbine flowmeter is enabled
In order to ensure trouble-free, safe start-up and commissioning of the ultrasonic flowmeter, the following pre-checks must be carried out:
1. Before starting the flowmeter officially, be sure to handle each leak point;
2. Check the power supply voltage on the terminal block and the corresponding positive and negative polarity;
3. Check the polarity of the frequency output lead connected to the RS485 converter;
4. Check whether the gas turbine flowmeter and temperature/pressure transmitter display are correct and reliable, including the installation direction and verticality of the flowmeter; the sealing performance of all joints;
5, wiring inspection: should be in accordance with the system wiring diagram provided by Jiangsu Tianxin Instrument Co., Ltd., check all wiring is correct.
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.