Experimental Study On Response Characteristics Of Slug Flow In The Bending Pipe

This paper studies deeply the gas-liquid two-phase slug flow in the inner diameter of26mm; length is2m of the horizontal tube and central angle of30degrees,45degrees,60degrees,90degrees, circumference of0.5m elbow, which is of great significance to perfect theslug flow in pipe and practical application. The main research contents and conclusions are asfollows:In horizontal tube and pipe bending convert liquid velocity of slug frequency effect ismuch larger than the effect of superficial gas velocity. Increase the amount of pipeline gas andliquid in respectively or simultaneously in horizontal pipe and elbow, can cause an increase ofpressure/differential pressure and maximum pressure/differential pressure in pipeline runningprocess.The probability density distribution of differential pressure signal is mainly characterizedby a unmoral distribution and normal distribution of horizontal section plug flow, and abimodal distribution of bend slug flow, had obvious difference between them, but theprobability density of dispersion is commuted with superficial gas velocity and liquid velocityincreases. The signal showing a diversity of distribution unmoral, bimodal and multimodal inthe bend, and with the increase of gas and liquid superficial velocity or angular velocity of thecenter increases, the probability density distribution appeared more multimodal distribution.Horizontal section plug flow pressure difference of the power spectrum function is underthe condition of convert liquid velocity is constant, along with the increase of superficial gasvelocity, the differential pressure fluctuation signal in the frequency range wider, amplitude,superficial gas velocity, under the condition of constant frequency spectrum characteristics ofdifferential pressure fluctuation along with the change of equivalent liquid velocity shows thecharacteristics of complex changes. In the same conditions, the differential pressure andbending power spectrum distribution function and horizontal section plug flow compared tothe main power spectrum distribution function of the frequency range is larger, and thecharacteristics of large amplitude. In the same central Angle bend in the conversion of liquid atconstant speed, bend slug flow stress of the power spectrum function are the main changes inthe frequency range is not big, the characteristic of the large amplitude, and when thesuperficial gas velocity is constant, the frequency is the main pressure power spectrum rangehad no obvious change rule, and the characteristic of the large amplitude. And with the increase of bend central Angle, its bent pipe pressure fluctuation of slug flow of thepower spectrum function had no obvious change rule.