Applicability of clamp-on ultrasonic flow meter to wet steam in carbon steel pipes of different diameters

Abstract

It is particularly vital to grasp accurately the steam flow rate at the demand end from the viewpoint of energy conservation. A clamp-on ultrasonic steam flow meter is useful for a factory since it is not necessary for pipe processing. The steam in the steam piping of factories often has a wet steam flow caused by, for example, heat loss, heat supply, and work. It is well known that the measurement error of the steam flow rate is caused by steam wetness. However, the method of estimating the measurement error has not yet been established since it is difficult to evaluate the effects of steam wetness quantitatively in plants and factories. We have conducted wet steam flow tests with this clamp-on ultrasonic flow meter and found some characteristics. In this study, we conducted steam flow test with the same flow meter for carbon steel piping of diameter different from those of our previous measurement. On the basis of the measurement results, we considered a method of applying a clamp-on ultrasonic flow meter to flow rate measurements under wet steam by correcting the density in the flow rate calculation.