CAJ | 학술논문

在自主研发的密相气力输送实验装置上，以N2作输送载气，以3种不同粒径的褐煤作输送物料进行输送实验，运用域重标分析方法对水平管差压信号和料罐质量脉动序列进行了 Hurst 指数分析，并采用统计学方法对料罐质量脉动序列进行了标准差分析，从管内流动和料罐出料出发，对整体输送稳定性进行了探讨。结果表明：水平管差压信号Hurst指数Hdp能较好地表征管内流动稳定性，而料罐质量脉动Hurst指数Hma则需结合标准差分析才能更好地表征料罐出料稳定性。以表观气速与跃移速度比值K为特征参数进行探讨，在K=1.5左侧，随着K值减小，Hdp减小，管内流型发生转变，甚至可能发生堵管，管内流动稳定性变差，料罐质量脉动标准差增大，出料稳定性变差，整体输送稳定性变差；在K=1.5右侧，随着K值增大，Hdp减小趋势不明显，管内流动稳定性虽有变差的趋势，但不会发生堵管，而结合对料罐质量脉动序列的标准差分析，发现出料稳定性变差，甚至可能出现出料中断的情况，整体输送稳定性变差。
재자주연발적밀상기력수송실험장치상，이N2작수송재기，이3충불동립경적갈매작수송물료진행수송실험，운용역중표분석방법대수평관차압신호화료관질량맥동서렬진행료 Hurst 지수분석，병채용통계학방법대료관질량맥동서렬진행료표준차분석，종관내류동화료관출료출발，대정체수송은정성진행료탐토。결과표명：수평관차압신호Hurst지수Hdp능교호지표정관내류동은정성，이료관질량맥동Hurst지수Hma칙수결합표준차분석재능경호지표정료관출료은정성。이표관기속여약이속도비치K위특정삼수진행탐토，재K=1.5좌측，수착K치감소，Hdp감소，관내류형발생전변，심지가능발생도관，관내류동은정성변차，료관질량맥동표준차증대，출료은정성변차，정체수송은정성변차；재K=1.5우측，수착K치증대，Hdp감소추세불명현，관내류동은정성수유변차적추세，단불회발생도관，이결합대료관질량맥동서렬적표준차분석，발현출료은정성변차，심지가능출현출료중단적정황，정체수송은정성변차。
Based on a self-developed dense phase pneumatic conveying system, conveying tests of three lignite pulverized coal with different mean particle sizes using N2 as carrier gas were carried out. The Hurst exponents of pressure drop fluctuation signals in horizontal pipe and mass pulsations of material storage tank were calculated using rescaled range analysis. The standard deviations of mass pulsations were analyzed. The Hurst exponent and standard deviation were used as an indicator of conveying stability. The flow stability of conveying pipe was well characterized by Hurst exponents of pressure drop fluctuation signals (Hdp), while the discharge stability of material tank was not well characterized by Hurst exponents of mass pulsations (Hma) and standard deviation analysis was required. Conveying stability was investigated according to the ratio of superficial gas velocity to saltation velocity (K). At the left side of K=1.5, Hdp decreased with the decrease of K, the flow regime in gas-solids horizontal conveying pipe was changed and even caused a pipe blockage, the flow stability of conveying pipe became worse. Meanwhile, the standard deviation of mass pulsations increased as K decreased, the discharge stability of material tank deteriorated, and conveying stability became worse. At the right side of K=1.5, as K increased, decreasing trend of Hdp was not obvious, through combined analysis with standard deviation analysis, discharge stability became worse and might cause interruption of discharging.