Narrow slit Venturi throttling set and gas-liquid two-phase flow measuring system

Abstract

The invention pertains to the technical field of fluid measurement, which relates to a slit Venturi throttle device, including an entrance, a contraction section, a slit section, an expansion section and an exit which are connected sequentially, the contraction section is a section of long narrow pipeline, the cross-section of the contraction section takes a shape of a long narrow rectangle, and the area of the cross section thereof is smaller than the area of the cross sections of the entrance and the exit. The invention also provides a two-phase flow measurement system which adopts the throttle device. The Venturi throttle device and the two-phase flow measurement system which are provided by the invention can effectively eliminate the influence of the friction pressure drop on the measurement, the devices can be applicable to the different gas-liquid two-phase media, different pipeline materials and other working conditions, and the factors which are related with the friction forceand affect the measurement can be reduced or eliminated. The invention makes use of the gravity potential pressure difference pulse signals and the time equalization signals which are perpendicular to the horizontal flow direction, at the same time, the invention can avoid the influence of the frictional resistance and accurately identify the flow type and measure the fraction rate, furthermore, the implementation is simple and convenient.

Description

Technical field [0001] The invention belongs to the technical field of flow measurement, and relates to a two-phase flow phase holdup and flow measurement system. Background technique [0002] Two-phase flow refers to a flow system composed of two-phase substances (at least one phase is fluid). If there are more than two phases in the flow system, it is called multi-phase flow. Two-phase or multi-phase flow is the most common viscous fluid flow involved in the completion of phase change mass transfer and reaction processes in chemical production. Heat transfer during phase change, gas absorption in tower equipment, liquid rectification, liquid extraction, and chemical reaction processes in stirred tanks or bubble columns, all involve two-phase flow. In the measurement of oil, gas and water three-phase flow in the petroleum industry, a two-phase flow is obtained after preliminary separation of the fluid by a separation device. Two-phase flow fluids are divided into gas-liquid, g...

AI Technical Summary

Problems solved by technology

The problem with this method is whether the gas-liquid ratio of the two-phase fluid in the sampling part is consistent with the ratio in the original flow; whether the sampling ratio (constant) itself is affected by the flow pattern, flow fluctuation, etc.

If the volume of the measuring device is too large, it is difficult to ensure that the flow parameters of the two-phase fluid flowing through each component of the combined device are consistent, so there is a principle error

In addition, the differential pressure taken by the traditional differential pressure flowmeter usually includes the frictional pressure drop. In the gas-liquid two-phase flow, the frictional resistance has a significant impact on the measurement. How to measure only the accelerated pressure drop of the differential pressure flowmeter and not The absence of frictional pressure drop is the key to accurate measurement

Images