The main factors affecting the up and down fluctuations of the superheated steam flowmeter
Author: Source: Date: 2021-05-25 15:28:11
(1) The upstream and downstream straight pipe sections are insufficient.
For traditional vortex or orifice flow meters, straight pipe sections are required to be installed before and after 20D and 5D respectively. If the upstream and downstream straight pipe sections are insufficient, the fluid will not develop fully, and turbulence and velocity profile distortion will occur. The distortion of the velocity profile is usually caused by local obstacles (such as valves) or bends in the pipeline, while the vortex is usually caused by two or more spatial (three-dimensional) bends. The shortcomings of the upstream and downstream straight pipe sections can be adjusted by installing flow regulators. The simplest and most effective method is to use a flow meter with lower requirements for upstream and downstream straight pipe sections.
(2) The turndown ratio is insufficient.
Turndown ratio refers to the ratio of the maximum flow rate and the minimum flow rate that the flowmeter can measure within a given range of accuracy and reproducibility. But you must be cautious in terms of turndown, because turndown is based on the actual flow rate. The maximum allowable speed of the steam system is generally 35m/s. Higher flow rates will cause corrosion and noise in the system. Different flowmeters allow different minimum flow rates. Generally, the minimum steam flow rate measured by a vortex flowmeter is 2.8m/s. When the turndown ratio is insufficient, a flowmeter with a large turndown ratio or multiple flowmeters in parallel should be used.