现场测量的时候，经常会由于一些客观的因素而导致测量结果误差较大，下面就给大家主要介绍下保证孔板流量计测量精度的主要措施： When the orifice plate flowmeter is measured on the spot, the measurement results often have large errors due to some objective factors. Here are the main measures to ensure the accuracy of the orifice plate flowmeter:
1. Orifice flowmeters are calibrated one by one. Everyone knows that standard orifice plates can be used directly as long as they are designed and manufactured in accordance with relevant standards, without the need for actual flow calibration. Because the outflow coefficient can be calculated directly by software, but the computer calculation is ideal after all, and there is still a certain difference from the field environment. Therefore, in order to ensure the measurement accuracy, it is recommended to perform a real-flow calibration on each flowmeter to calibrate the outflow. The coefficient is compared with the calculation result, and the difference is calculated and corrected. 2. Reynolds number correction. There is a definite relationship between the flow coefficient of the orifice flowmeter and the Reynolds number. When the mass flow rate changes, the Reynolds number changes in proportion to the change in the flow coefficient. 3, the effect of temperature on the orifice plate flowmeter and its correction, changes in the density of the fluid caused by the temperature change of the fluid, resulting in changes in the relationship between differential pressure and flow, and secondly, the change in temperature caused changes in the inner diameter of the pipe, the orifice opening The correction of temperature change is to use a temperature meter to measure the temperature on the spot and then input it to the secondary meter to correct the error caused by the temperature change. 4. Swellability correction. When measuring the flow of steam and gas with an orifice flowmeter, the fluid's expandability must be corrected. For specific correction coefficients, refer to the throttle device design manual. 5. Calculation of steam mass flow rate. When the orifice flow meter measures steam, the flow rate value is obtained from the differential pressure signal, and then the density is calculated from the steam temperature and pressure value check table to calculate the steam flow mass.
In fact, the orifice plate flowmeter to find the flow is very widely used by us, and it is also a representative of the differential pressure flowmeter. You can promote other differential pressure flow meters through appropriate inference.
XHLG series orifice flowmeter is a differential pressure generating device for measuring flow rate. It can be used with various differential pressure gauges or differential pressure transmitters to measure the flow rate of various fluids in pipelines. The orifice plate flow meter throttling device includes an annular chamber orifice plate, a nozzle and the like. Orifice flowmeter throttling device is used together with differential pressure transmitter to measure the flow of liquid, steam and gas. Orifice flowmeter is widely used in petroleum, chemical, metallurgy, power, light industry and other departments.
The fluid filled with the pipeline, when they flow through the throttle device in the pipeline, the flow beam will form a local contraction at the throttle of the throttle device, thereby increasing the flow velocity and low static pressure, so it is generated before and after the throttle. The pressure drop, that is, the pressure difference, the greater the flow rate of the medium flow, the greater the pressure difference generated before and after the throttle, so the orifice flowmeter can measure the flow rate of the fluid by measuring the pressure difference. This measurement method is based on the laws of energy conservation and flow continuity.
)是集流量、温度、压力检测功能于一体，并能进行温度、压力自动补偿的新一代流量计，该孔板流量计采用先进的微机技术与微功耗新技术，功能强，结构紧凑，操作简单，使用方便。 Intelligent throttling device ( orifice flowmeter ) is a new generation flowmeter that integrates flow, temperature and pressure detection functions and can automatically compensate for temperature and pressure. The orifice flowmeter uses advanced microcomputer technology and micropower consumption. New technology, strong function, compact structure, simple operation and easy to use.
Second, characteristics ▲ orifice plate flow meter throttling device structure is easy to copy, simple, sturdy, stable and reliable performance, long service life, low price.
▲ Orifice plate calculation adopts international standards and processing. ▲ Orifice plate flowmeters have a wide range of applications. All single-phase flows can be measured, and some mixed-phase flows can also be applied.
▲ The standard throttling device can be put into use without actual flow calibration.
▲ Integrated orifice flowmeter is simpler to install, without the need for a pressure pipe, and can be directly connected to a differential pressure transmitter and a pressure transmitter.
Features of Intelligent Orifice Flowmeter ▲ Using imported single crystal silicon intelligent differential pressure sensor ▲ High precision and perfect self-diagnosis function
可同时显示累计流量、瞬时流量、压力、温度。 ▲ The intelligent orifice plate flowmeter can simultaneously display the accumulated flow, instantaneous flow, pressure, and temperature.
▲ In addition to the online and dynamic full compensation function, the smart orifice plate flow meter also has self-diagnosis and self-setting range.
▲ Equipped with a variety of communication interfaces ▲ High stability ▲ Wide range, greater than 10: 1
Technical index of intelligent orifice plate flow meter ▲ High accuracy: ± 0.075%
▲ High stability: better than 0.1% FS / year ▲ High static pressure: 40MPa
▲ No need to adjust for 5 years of continuous operation ▲ Can ignore the effects of temperature and static pressure ▲ Resistant to high overpressure