Test device for gas desorption by heating coal with high temperature steam

Abstract

The invention discloses a test device for desorbing gas by heating a coal body through high temperature steam and belongs to the technical field of coal bed gas injection intensified exploitation.By means of the test device, the technical problem that at present, no test device for promoting gas desorption by heating the coal body through high temperature steam exists is solved.The test device is composed of an automatic water injection system, a steam generating system, a gas injection system, a gas desorbing system, a steam condensation system and a gas collecting system, water is heated through three heating chambers in the steam generating system, overheat steam is generated, and the injection speed of water is controlled through an automatic metering water injection pump, so that the steam enters a coal sample adsorption vessel at the constant speed; the steam condensation system cools and condensates the steam obtained after a coal sample is heated; water formed after steam condensation is drained through a drainage valve.The test device is used for coal body gas adsorption and desorption experimental investigation and has the advantages of being simple and reasonable in structure and capable of simulating heat field distribution generated after the high temperature steam enters the coal body and scientifically studying the gas desorption intensifying effect after the steam is directly injected into the coal body.

Description

technical field [0001] The invention belongs to the technical field of heat-injection-enhanced extraction of coalbed methane, and in particular relates to a test device that uses high-temperature steam to heat coal bodies to promote gas desorption. Background technique [0002] Gas in coal seams generally exists in coal seam pores and fissures in two states of adsorption and dissociation, of which the adsorption state accounts for about 80% to 90%. In coal bodies, adsorbed gas and free gas are generally in a state of dynamic equilibrium, that is, adsorbed gas and free gas are in constant exchange. When the state of the coal body changes, such as a drop in gas pressure and a change in temperature during coal mining, the gas in the adsorbed state will be desorbed, and a large amount of gas will be transformed into free gas. [0003] In coal seam mining, gas desorption sometimes occurs instantaneously and in large quantities, which not only increases the difficulty of mining, ...

AI Technical Summary

Problems solved by technology

However, this method will involve the fracturing and permeability enhancement of the coal seam by water vapor, the promotion of desorption by temperature and the inhibition of desorption by water, which is a complex problem to be solved

[0006] At present, in the experimental research of coal gas adsorption and desorption, there is no test device that uses high-temperature steam to heat coal to promote gas desorption

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