Experimental Study On The Relationship Between Water Lock Effect,Temperature And External Liquid Concentration

This thesis relies on the National Natural Science Foundation of China —experimental study on the relationship between water lock formation speed and water lock effect and the main influencing factors(No.51574116).Taking the coal falling in the working face of the high gas mine as the research object,and using the water lock to prevent and control the coal seam gas overrun as the theoretical basis,and aiming at the problem of temperature difference in different areas of the coal mine,this paper explores the influence of temperature and external liquid concentration on the effect of water lock after the external liquid intrudes into the coal body,and carries out relevant experimental research.By using the experimental device of gas desorption under the condition of external liquid intrusion,taking the gas desorption release amount and gas desorption release rate as the measurement standard of water lock effect,the experimental research on water lock effect of external liquid intrusion into gas bearing coal body at different temperatures and the experimental research on water lock effect of external liquid intrusion into gas bearing coal body at different concentrations were carried out.Through the comparative analysis of the cumulative gas desorption release and the maximum gas desorption release rate after the invasion of different water lock solutions,the water lock solution with the best water lock effect and its concentration at different temperatures were found out,and suggestions are proposed for the practical application of the project.Through the research of the paper,the following conclusions are obtained:(1)There is not a single relationship between the external liquid concentration and the water lock effect.There is a concentration threshold between 0.05% and0.075% concentration.Before the concentration,as the external liquid concentration increases,the better the water lock effect.After the concentration,as the external liquid concentration increases,the water lock effect becomes worse.(2)There is not a single relationship between temperature and water lock effect.When the temperature is lower than 21?,the lower the temperature is,the better the water lock effect is when the external liquid invades the gas-containing medium.But when the temperature is higher than 21?,the lower the temperature,the water lock effect after the external liquid invades the coal containing gas will not be better with the lower temperature.(3)The best water lock solution and its concentration can be determined at different temperatures by comprehensively considering the delay and inhibition of gas desorption and release after the external liquid invades the gas bearing coal body at different temperatures.When the temperature is 14?,the water lock effect of 0.05%and 0.075% JT304 solution is better.When the temperature is 17 ?,the water lock effect of 0.05% JT302,JT303 and JT304 solution is better.When the temperature is21?,the water lock effect of 0.05% JT302 solution is better.When the temperature is24?,the water lock effect of 0.05% JT302 and JT304 solution is better.When the temperature is 27?,0.05% JT302 and 0.075% JT304 solution have better water lock effect.This study explores the influence of temperature and external liquid concentration on the effect of water lock,which provides a reference for the engineering application of water lock to prevent gas overrun,and for the optimization of water lock solution and its concentration under different temperature conditions.