弯管流量计测量特性的数值模拟与试验研究

为了优化弯管流量计的测量,综合运用流场数值模拟和实流标定试验两种方法,研究了弯管流量计的测量特性.在对安装有弯管流量计的流场数值模拟的基础上,根据压力分布特点确定了较优的取压口斜度;然后,在内径为100 mm的管道中用空气进行了实流标定试验.结果表明:为了增加差压测量的灵敏度和减小二次流对测量的影响,可将弯管流量计的取压口选取在与上游端面成45°夹角的地方;在试验范围内不同流量下,弯管流量计的流量系数都比较稳定,相对误差都介于±3%之间,能够满足大多数工业现场流量测量的要求.

Numerical simulation and experimental research on measurement characteristics of an elbow meter

In order to optimize its measurement, numerical simulations and calibration tests were conducted on an elbow meter, of which measurement characteristics was studied. Based on the findings from numerical simulations for the flow field of the elbow meter, a suitable port angle was determined according to the pressure distribution in the meter. Then experiments were carried out in a DN100 pipe with airflow. The results show that, first of all, 45o port angle may increase the sensitivity of pressure measurements and decrease the influence of frictional secondary flow on the flow measurement; Second, in the flowrate range studied, the flow coefficients of the elbow meter is stable, and its relative errors are all less than ±3%, which can satisfy the fluid flow measurement in most industrial applications.