Research on the detection of fouling and slagging in cold state based on capacitance principle

Abstract

Aiming at the requirement of on-line monitoring for the fouling and slagging in the syngas cooler of coal gasifier, this paper proposes a detection method of deposition thickness based on the capacitance principle. A capacitance measurement rig for deposition detection is built to conduct a cold state simulation experiment. The coal ash and syrup are selected as medium to simulate the fouling and slagging in cold state. Two kinds of electrodes including single-electrode and double-electrode probes are used to measure the capacitance of deposition. The results show that the measured capacitance increases linearly with the increase of the deposition thickness for all the cases. The linear correlations between the capacitance value and the deposition thickness are obtained for ash and syrup under two kinds of electrodes, respectively. Verification tests show that the predicted deposition thicknesses by employing the linear correlations are basically consistent with the real thickness, and the maximum error is 5.15%. The detection error with single-electrode is less than that with double-electrode due to more deposition amount between two electrodes.