Abstract: In order to solve cooling problem in the process of deep mining in coal mines,this paper presents a new method using liquid CO₂ as cold source to control heat damage. For exploring the effectiveness of this cooling method, a liquid CO₂ phase transition cooling device was designed to make the ground-based tests aiming at studing cooling effect of liquid CO₂ and its utilization rate. The results show that when injection flow rate of liquid CO₂ are respectively 14.722, 16.484, 19.168 and 23.146 kg/min, the corresponding cooling capacity are respectively 89.8 , 97.2, 109.6 and 128.6 kW, airflow temperature decreases by 6.2,6.8,7.5and 8.6 ℃,and the moisture content decreases by 2.746, 3.066 5, 3.613 5 and 4.095 g/kg, the utilization rate of liquid CO₂ cooling capacity reaches more than 95%, that when liquid CO₂ injection amount increases to a certain extent, the cooling capacity of the cooling system reaches the maximum, and that the humidity coefficient of heat exchanger is positively correlated with the relative humidity of inlet air flow.

Key words: mine cooling, liquid CO₂, cooling by phase transition, cooling effect, utilization rate of cooling capacity