Coal sample gas desorption device and measuring method capable of simulating variable temperature and variable pressure

Abstract

The invention discloses a coal sample gas desorption device capable of simulating variable temperature and variable pressure. The coal sample gas desorption device comprises a gas desorption mechanism, a back pressure mechanism communicating with the gas desorption mechanism, a weighing mechanism connected with the back pressure mechanism, an inflating mechanism connected with the gas desorption mechanism and a vacuumizing mechanism connected with the gas desorption mechanism, wherein the gas desorption mechanism comprises a reference tank and a coal sample tank which communicating with each other, the reference tank simultaneously communicates with the inflating mechanism and the vacuumizing mechanism, and the coal sample tank communicates with the back pressure mechanism. According to the desorption device in the technical solution, the desorption environment temperature of the coal sample is accurately set through the constant-temperature water bath, the desorption environment pressure of the coal sample is accurately set through a backpressure loading tank, and the desorption device can be used for researching the gas desorption rule of the coal sample under different environment temperature and backpressure combination conditions and can realize the technology for measuring the coal seam gas content through ground all-air reverse circulation drilling sampling according tothe gas desorption theory under the variable-temperature and variable-pressure conditions.

Description

technical field [0001] The invention relates to the technical field of coal seam gas content measurement, in particular to a coal sample gas desorption device and a measurement method for simulating variable temperature and variable pressure. Background technique [0002] Coal seam gas content is one of the important parameters to reflect the occurrence of coal seam gas. It is an important factor for calculating coal seam gas reserves, predicting mine gas emission, designing gas drainage, evaluating the risk of coal and gas outburst, and meeting gas control and drainage standards. in accordance with. According to the difference of gas content measurement process, it is generally divided into direct method and indirect method; according to the difference of measurement space, it is generally divided into surface measurement and underground measurement. At present, the direct method for measuring coal seam gas content in underground coal mines is relatively mature, and the er...

AI Technical Summary

Problems solved by technology

At present, the direct method for measuring coal seam gas content in underground coal mines is relatively mature, and the error can be controlled within 7%. The direct method is also mostly used for surface measurement, but the compensation for gas loss in the sampling process is not accurate, resulting in an error range of 20% for gas content determination. %~30%

At the same time, the previous sampling methods for ground gas content measurement all used the rope coring method, which was slow in sampling speed and low in success rate. However, the drilling sampling method using full air reverse circulation can make the drilling cuttings at the bottom of the hole > 15m / s However, since the cuttings have undergone changes in temperature and pressure along the process of transportation in the central tube of the double-walled drill pipe, the research on the gas desorption law of coal samples under the condition of variable temperature and pressure is the key to ensure that the ground well The premise of accurate compensation of gas loss in the whole air reverse circulation sampling process

Images