The Study Of Wet Gas Measurement Technology For Applications: Venturi Tube

Nowadays, the measurement of the two-phase flow has been well-known, no matter in nature or in industrial field. Wet gas, as one special types of the two-phase flow, can be seen in many important applications such as oil-gas exploration, electricity power generation and so on. The elementary research on water-gas two-phase flow started in the middle of the passed century, during the end of the last century and the beginning of this century, commercial wet gas meters were produced out by several corporations such as AGAR, ISA etc. and later applied successfully, North Sea of England, Gulf of Mexico locating in America are good examples.In the background of low pressure condition, the wet gas measurement using a venturi tube was studied. The work involved in this dissertation can be cut into 4 parts, including principle analysis, design of experiment facility, real flow experiment and half-experiential model deducing.Firstly, some basic parameters of wet gas measurement and"overreading theory"were introduced, besides, some classical wet gas models on venturi tube were compared to each others, furthermore, based on the two-phase flow hydrodynamics, a stratified flow model was deduced from the momentum equation.Secondly, three-phase flow experiment facility was upgraded. An horizontal located wet gas experiment pipe was designed and its accessorial equipments were constructed, besides, the computerized date collecting and controlling system was built up, using a industrial computer and some date collecting cards based on PCI bus in hardware, MCGS configuration software and Visual Basic 6.0 in software.Thirdly, lots of real flow experiments were done to study how gas velocity, pipe pressure, liquid fraction and size of venturi tube affect on the overreading of venturi tube, besides, many classical wet gas measurement models on venturi tube were proved to be unsuitable for low pressure condition, and couldn't overcome the non-linear of overreading-liquid fraction figure when the pressure was low.