Dust-suppression and cooling effects of spray system installed between hydraulic supports in fully mechanized coal-mining face

Spray systems installed between hydraulic supports are crucial for suppressing the dispersion of coal dust at fully mechanized coal-mining faces, and evaporative cooling by water spray is increasingly being applied to enhance thermal comfort in built environments. Hence, this study proposes the installation of a spray system between hydraulic supports to perform dust suppression and cooling at a fully mechanized coal-mining face. An experimental platform is established to perform the spray experiments and thereby obtain reasonable and reliable boundary conditions for the numerical simulation. The physical parameters of the rotary solid cone-shaped wideangle nozzles (featuring an aperture of 2 mm and an "X" guiding core) are measured at different spray pressures (2, 4, 6, and 8 MPa). The atomization effects of the spray system under various pressures are studied using numerical simulations. The results indicate that when the spray pressure is 6 MPa, the droplet can prevent dust suppression on the working face, thereby effectively preventing dust diffusion. In addition, the air temperature distributions around the working face at different spray-water temperatures are obtained. The most economical water temperature and effective cooling distance of the spray system are determined as 283 K and 10 m, respectively. Finally, a multigroup spray system arrangement is proposed. The field temperature measurement results verify the cooling effect. This study provides an alternative solution for dust suppression and cooling engineering around hot mining faces.