State recognition method of dense-phase pneumatic conveying of pulverized coal under high pressure

The stability and monitoring of dense-phase pneumatic conveying of pulverized coal under high pressure has a significant meaning for coal gasification engineering application. A novel array electrostatic sensor based method was presented to achieve the recognition of the flow stability and flow regime of dense gas-solid two-phase flow. Multi-scale decomposition was firstly performed for the electrostatic signals of every electrode of the array electrostatic sensor by EMD,and the sample entropy and energy ratio were calculated for every scale electrostatic signal component. Finally through the comparison and analysis of the multi-scale sample entropy and multi-scale energy ratio,the recognition of the particles flow stability and flow regime was achieved. The experimental results indicated that the consistency of the multi-scale sample entropy of the array electrostatic signals presents the stability of dense gas-solid two-phase flow,and the multi-scale energy ratios present the particles distribution and flow regime within pipeline;the low-scale compo- nents(1,2 scale) of the electrostatic signal contain the information of the suspended particles flow,and the high-scale components(3 scale above) contain the information of the great particles group flow along the bottom of the pipe.