Flowmeter products for natural gas flow measurement generally include: gas turbine flow meter, precession vortex flow meter, vortex flow meter, etc.
1. Introduction to gas turbine flowmeter：
This instrument is a frequently used natural gas flow measuring instrument at present. It has the advantages of simple structure and easy installation; relatively small dimensions; high accuracy; good repeatability; and the wide range can reach 10:1. In the case of high-pressure gas transmission The range can be further increased; its output is a pulse frequency signal, so when used with a programmable flow display meter, it is easy to obtain lower system uncertainty.
Its shortcoming is that the turbine rotates at high speed, there is mechanical friction between the bearing and the shaft, and the service life is not very long. Therefore, attention should be paid to lubrication. You can use the lubrication method provided by the manufacturer to replenish lubricating oil regularly. In addition, if the high-speed flowing gas contains large solid particles, the turbine blades can easily be damaged. Therefore, a filter should be installed on the pipe in front of the flow meter.
2. Introduction to precession vortex flowmeter：
The precession vortex flowmeter is currently the preferred flowmeter product for measuring natural gas. It has temperature and pressure compensation, dual power supply mode (24VDC and battery), and it has a wide operating temperature range; a large range; the Reynolds number is within a certain range and does not Affected by fluid temperature, pressure, density and viscosity; it has strong applicability. Unless it contains larger particles or longer fiber impurities, it is generally not necessary to install a filter; the requirements for the upstream and downstream straight pipe sections are low, and the upstream 4D and downstream 2D straight pipe sections are The pipe section is enough; the output frequency has a linear relationship with the volume flow rate.
It is simple to install and maintain, with high reliability and price ratio. The body material can be selected from aluminum alloy or stainless steel, with LCD display. Standard output mode: pulse output, 4~20mA output, RS485 communication, Hart (optional), which can be realized Interface with industrial automation systems.
Its disadvantage is that the pressure loss is large. Secondly, the precession vortex flowmeter is a fluid vibration flowmeter and is sensitive to pipeline vibration and electromagnetic interference, so it can only be used in an environment with small vibration and no electromagnetic interference.
3. Introduction to vortex flowmeter：
Currently, vortex flowmeters are generally used in the internal assessment of natural gas and measurement of energy consumption in industrial and mining enterprises. They have reasonable overall structural design, wide dynamic measurement range, and small pressure loss. The instrument body can be made of stainless steel and is suitable for corrosive applications. Measurement of media; the instrument has no moving parts and is easy to install and maintain; it has on-site LCD display, pulse, 4-20mA output or 485 serial communication interface, and can be connected to industrial automation systems and many other advantages.
