This paper comprehensively analyzes the permeation plugging and coal self-heating inhibition of the thermo-responsive secundina sphere inhibitor (TRSSI) composed of a phase change shell and an internal saltwater inhibitor. Experimental setups included a coal sample leak-blocking device and a coal self-heating adiabatic oxidation platform. The inhibitor's inhibition mechanism was studied using infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Results indicate that smaller particle sizes enhance the bonding of the shell phase change material to coal particles, improving air blocking. In a condensed coal sample with a 1-3mm particle size, the pressure difference at both ends is 1.4 times higher than in a loose coal sample. The TRSSI exhibited significant inhibition effects throughout the coal self-heating process. Initially, the TRSSI's shell absorbs the heat from the coal, causing the TRSSIs to deform and accumulate on the coal surface. This process effectively slows down the rate at which the coal surface heats up. At the same heat source temperature, the heating rate of the raw coal sample is 4.02 ℃/d, while the heating rate of the inhibition coal sample is only 2.35 ℃/d. Later, the TRSSI released a sufficient amount of internal inhibitor liquid that precisely acted on the center of the coal seam heat source, causing the heat source temperature to drop from 180 ℃ to 50 ℃ rapidly. Microscopic analysis revealed a decrease in oxygen-containing groups, hydrocarbons, and -C=C in inhibited coal samples, making self-ignition more challenging. Furthermore, the TRSSI's shell envelops the coal seam post phase change, delaying self-thermal oxidation by isolating coal from oxygen contact.

Thermo-responsive; coal; low temperature oxidation; inhibition