Coal seam gas content is a fundamental data for determining gas emission and is one of the important parameters in mine gas drainage design and mine ventilation design. To some extent, coal seam gas content depends on coal seam gas pressure. Therefore, coal seam gas content and coal seam gas pressure are two important paired parameters in coal mine safety production.
The WP-1 downhole rapid coal seam gas content measuring instrument developed by us is designed based on the principle that the change in gas desorption rate of coal samples follows a power function relationship. It uses the gas desorption characteristic index V1 value to calculate coal seam gas content and coal seam gas pressure. In the design, microcontroller control technology and gas flow sensing technology are adopted. The WP-1 rapid coal seam gas content measuring instrument employs a resistance-free micro gas flow measurement principle, making the coal sample desorption process closer to the natural desorption state of coal. To ensure accurate measurement results, numerical averaging is applied to the collected data in the software, giving the instrument features such as simple circuitry, small size, light weight, portability, and ease of operation.
WP-1 Rapid Coal Seam Gas Content Measuring Instrument Features
The coal seam gas content measuring instrument is suitable for use in coal mine underground mining or tunneling faces to quickly measure the gas desorption volume in coal. It can promptly grasp the distribution of gas content (W) and gas pressure (P) ahead of the working face, as well as changes in important gas parameters such as outburst prediction indicators K1 and K2, forming a relatively complete set of technologies. Its characteristics include short measurement time (the entire process takes 7 minutes: 2 minutes for preparation and 5 minutes for desorption), no interference with normal face operations, automatic completion of measurement, collection, calculation, storage, display, printing, and other tasks. It is easy to operate, time-saving, labor-saving, fast, and accurate. A single measurement can predict multiple important gas parameters. It provides a rapid and concise measurement method and scientific basis for high production, safety production, gas emission prediction, and rational development and utilization of gas resources in production mines. Similarly, the coal seam gas content measuring instrument is also suitable for laboratory research and testing work.
WP-1 Rapid Coal Seam Gas Content Measuring Instrument Performance Indicators
K1—Gas desorption rate decay coefficient of coal sample, one of the important indicators of coal seam gas hazard
Kt—One of the important indicators of coal seam gas hazard, ml/g·min
V1—Gas desorption rate per minute per unit weight of coal sample, directly related to coal seam gas content and coal seam gas pressure, ml/g·min
Q2—Gas desorption rate decay coefficient
P—Predicted value of coal seam gas content, ml/g
W—Predicted value of coal seam gas pressure, MPa
R—Correlation coefficient, reflecting the measurement results
WP-1 Rapid Coal Seam Gas Content Measuring Instrument Technical Parameters
Gas desorption volume: 0–6 ml/min
Gas content: 2–30 ml/g
Gas pressure: 0.1–6.0 MPa
Measurement accuracy: ±2%
Display method: 8-digit liquid crystal (LCD) display
Continuous operation time: Over 8h
Operating environment temperature: 0–40°C
Operating environment humidity: ≤95%
Operating environment pressure: 85–110 kPa
Dimensions and weight: 250×145×67 mm;