高压浓相煤粉气力输送差压信号多分辨分析

为了探究高压浓相气力输送过程中时频空间的内部特征,利用六尺度多分辨小波分析对试验差压信号进行时频分解.引进能量、Shannon熵和标准差STD作为特征量对气固两相流频域空间进行分析.分析表明:浓相气力输送过程中,差压信号中的能量主要分布在低频区,Shannon熵从高频到低频上呈先减小后增大分布趋势.在相同的试验压力条件下,随着表观速度的增大,低频所占据的能量份额减小,信号脉动向高频移动;高频d1和d2的Shannon熵和a6上的STD增大,低频d4~d6上的Shannon熵和d1~d6上的STD减小.为进一步研究流型辨识及流动稳定性提供了新方法.

Application of multi-resolution analysis to differential pressure in dense-phase pneumatic conveying of pulverized coal under high pressure

In order to reveal intrinsic features of dense-phase pneumatic conveying in both time and frequency spaces,six scales wavelet multi-resolution analysis was employed to analyze experimental data of differential pressure.Energy,Shannon entropy and standard deviation were applied to characterize gas-solid two-phase flow in frequency space.The results show that energy of differential pressure signal mainly distributes in the low frequency region and Shannon entropy has the minimum value in the middle frequency region in the dense-phase gas-solid pneumatic conveying.Under same pressure,as the superficial velocity increases,the energy quotient in the low frequency region decreases,the signal fluctuation shifts to the high frequency region,the Shannon entropy in the high frequency space d_1 and d_2 and standard deviation(STD) of a_6 increase,and the Shannon entropy in the low frequency space from d_4 to d_6 and the STD in the entire frequency region from d_1 to d_6 decrease.The research provides a new approach for identifying regime and stability of the gas-solid two-phase flow.