STEAM FLOW METERING DEVICE AND METERING METHOD THEREFOR

摘要

Provided are a steam flow metering device and a metering method therefor. The device mainly comprises a mono-energetic gamma sensor (5), a Venturi-type flowmeter (6), a temperature transmitter (2), a pressure transmitter (3), a pipe connection section at the steam-inlet (1), and a pipe connection section at the steam-outlet (7), the function thereof being to measure the quantity of saturated water and saturated steam within the steam effectively and in real time. The measuring method thereof is: measuring the dryness of the saturated steam at the cross section by the mono-energetic gamma sensor (5); measuring the mass flow of the total steam by the Venturi-type flowmeter (6), and at the same time considering the potential slip (the phase velocity difference) existing in the saturated steam and the saturated water, such that the quantity of saturated steam, the quantity of saturated water and the corresponding thermal values thereof can be calculated in real time by a computer system by utilizing the method of analytical solution to the vapour/liquid annular flow slip. The vapour and the liquid phases in the steam can be directly distinguished and measured by the present measuring method. The present method is different from the conventional method of single-phase metering encryption correction, has no additional error, there is no influence from the type of flow and the phase change between the vapour and liquid, and has a higher measuring precision.