液态CO_2相变制冷降温试验研究

Experimental study on cooling by phase transition of liquid CO_2

为解决煤矿深井开采过程中的降温问题,提出一种以液态CO_2作为冷源的热害治理新方法,采用自行设计的液态CO_2相变制冷降温装置进行地面试验,研究液态CO_2降温效果及其冷量利用率,以验证该降温方法的有效性。结果表明:试验条件下,液态CO_2注入流量分别为14.722、16.484、19.168和23.146 kg/min时,对应制冷能力依次为89.8、97.2、109.6和128.6 kW,风流温度依次降低6.2、6.8、7.5和8.6℃,含湿量依次减少2.746、3.066 5、3.613 5和4.09 5 g/kg,液态CO_2冷量利用率达到95%以上;当液态CO_2注入量增加到一定程度时,该降温系统的制冷量达到最大;析湿工况下,换热器的析湿系数与入口风流相对湿度成正相关关系。

In order to solve cooling problem in the process of deep mining in coal mines,this paper presents a new method using liquid CO_2 as cold source to control heat damage.For exploring the effectiveness of this cooling method,a liquid CO_2 phase transition cooling device was designed to make the ground-based tests aiming at studing cooling effect of liquid CO_2 and its utilization rate.The results show that when injection flow rate of liquid CO_2 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 k W,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 5and 4.095 g/kg,the utilization rate of liquid CO_2 cooling capacity reaches more than 95%,that when liquid CO_2 injection amount increases to a certain extent,the cooling capacity of the cooling system reachesthe maximum,and that the humidity coefficient of heat exchanger is positively correlated with the relative humidity of inlet air flow.