Vortex flow meter to measure steam mass flow

sales01@cxflowmeter.com

The vortex flow meter is a volume flowmeter, that is, the fluid Reynolds number is within a certain range, and its output is only proportional to

 the volume flow. The output of the vortex flowmeter has a frequency signal and an analog signal, and the analog output is obtained by f/I 

conversion on the basis of the frequency output. There is about a 0.1% loss of accuracy in this conversion. Therefore, when used to measure

 steam flow, users prefer to use frequency output.

1

Several other reasons why the frequency output vortex flowmeter is more popular with users such as heating companies are as follows.

a. The price of frequency output vortex flowmeter is slightly lower (non-intelligent type)

b. It is more convenient to modify the full scale of the frequency output vortex flowmeter, which can be realized by simply operating the buttons

 on the panel of the programmable flow calculator according to the prescribed method.

c. To calculate the steam mass flow rate from the frequency signal output by the frequency output vortex flowmeter, it is only necessary to 

know the current working condition of the fluid, and the temperature and pressure compensation of the analog output vortex flowmeter is 

only the error caused by the deviation of the current working condition from the design working condition To compensate, it is therefore

 necessary to know not only the current operating conditions, but also the design operating conditions. The data of the latter working condition

 often causes errors due to the loss of data due to time lapse or personnel changes. In contrast, the frequency output vortex flowmeter does not

 have this problem.

2

The influence of humidity on the measurement results when choosing a vortex flowmeter. The output of the vortex flowmeter is only 

proportional to the flow rate of the fluid flowing through the measuring tube. When measuring wet saturated steam, the influence of water 

droplets on the output of the vortex flowmeter can be ignored, so it can be considered that the output of the vortex flowmeter is completely

 caused by wet caused by the dry part of the steam. The density of the dry part can be detected more accurately, whether it is pressure

 compensation or temperature compensation. The results of steam measurement are often used as the basis for economic settlement between 

the supply and demand parties. If the two parties agree to settle the cost according to the dry part of the steam, and the condensate water is 

not charged, the impact of phase change on the measurement is negligible and can be ignored.

3

Advantages of vortex flowmeters. Compared with the throttling differential pressure flowmeter, the vortex flowmeter has the following 

advantages.

(1) The structure is simple, firm, and easy to install and maintain. There is no need for pressure guide tubes and three-valve groups, etc., 

reducing leakage, blockage and freezing.

(2) The accuracy is high, generally ±(1~1.5)%R.

(3) The measurement range is wide, the caliber is reasonably determined, and the range can reach 20:1.

(4) The pressure loss is small, about 1/4~1/2 of the throttling differential pressure flowmeter.

(5) The output pulse signal is proportional to the flow rate, without zero drift.

(6) Within a certain Reynolds number range, the output frequency is not affected by the physical properties (density, viscosity) and composition

 of the fluid, that is, the instrument coefficient is only related to the shape and size of the vortex generator and the pipe.

sales01@cxflowmeter.com