Compression method and compression device for low-concentration oxygen-containing coalbed methane

Abstract

The invention discloses a low-concentration oxygen-bearing coal bed gas compression method which comprises the following steps: 1) precooling: precooling coal bed gas to the temperature of -15 DEG C to 10 DEG C; 2) pressurizing: pressurizing and compressing the precooled coal bed gas with the temperature not higher than 80 DEG C; 3) cooling; 4) judging: measuring the pressure of the cooled coal bed gas, feeding the coal bed gas to the next procedure if pressure of the coal bed gas reaches preset air pressure range, and otherwise repeating the step 1), the step 2) and the step 3) until the pressure of the coal bed gas reaches the preset pressure value range. The invention further provides a low-concentration oxygen-bearing coal bed gas compression device which comprises at least one stage of compression systems connected in series, and each compression system comprises a precooling heat exchanger, a compressor and a cooler. The low-concentration oxygen-bearing coal bed gas compression method and device can improve one-time supercharge ratio of the coal bed gas, reduces compression times and reduces compression energy consumption.

Description

technical field [0001] The invention relates to a gas compression method, in particular to a compression method and a compression device for low-concentration oxygen-containing coal bed gas. Background technique [0002] CBM belongs to the associated gas in coal mine production. Before coal mining, it is necessary to extract coalbed methane on the ground in advance; while mining coal mines, it is necessary to extract coalbed methane in mine tunnels. The coalbed methane extracted from the ground has high methane content, low oxygen content, good safety, and can be directly pressurized for transportation or used for other purposes. But more is for the safety of coal mining, coalbed methane extracted in mines that have already been mined and produced. The methane content of coalbed methane extracted in the mine is low, usually between 30% and 70%. This type of coalbed methane contains air, especially for coalbed methane with a methane content of less than 50%. Compression is...

AI Technical Summary

Problems solved by technology

Due to the process of pressurization, the temperature and pressure of coalbed methane will increase at the same time, which will lead to the expansion of the explosion range of coalbed methane

[0004] Conventional coalbed methane compression methods mainly consider its explosion-proof safety and avoid the danger of ignition sources. However, these coalbed methane compression methods require repeated compression of coalbed methane, many stages of compression, and high energy consumption for compression.

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