Study on Heat Transfer Behavior and Horizontal Seepage Expansion Mechanism of Liquid Nitrogen in Loose Media within Enclosed Spaces

Liquid nitrogen, characterized by its extremely low temperature and high vaporization expansion ratio, plays a crucial role in fire prevention and suppression in mining goafs. However, the seepage characteristics of liquid nitrogen in loose media have not been sufficiently studied. To improve the fire prevention and extinguishing efficiency of liquid nitrogen, it is essential to gain a deeper understanding of its seepage behavior in loose media. To this end, an experimental setup for liquid nitrogen seepage was designed to quantitatively study its horizontal seepage behavior in loose media. By analyzing the changes in the temperature and pressure fields during the seepage process, the effects of angle of inclination and particle size on the seepage process were explored. Based on the Forchheimer equation, a mathematical model for the horizontal seepage of liquid nitrogen in loose media was established. The results showed that when the particle size increased from 1–2 to 3–4 cm, the permeability increased by 4.2 to 4.5 times, and the non-Darcy factor decreased by 2.8 to 4.3 times. Under the same particle size conditions, as the angle of inclination increased from 0° to 13°, the permeability increased by 1.97 to 2.06 times, and the non-Darcy factor decreased by 1.37 to 2.11 times. This study provides a theoretical basis for the application of liquid nitrogen in fire prevention and extinguishing in mine goafs.