液氮冻结管内沸腾段分布特征的试验研究  

Experimental study on the distribution of boiling sections in liquid nitrogen freezing pipe

作　　者：石荣剑[1,2] 岳丰田[1,2] 张勇[1,2] 陆路[1,2] 

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008 [2]中国矿业大学力学与建筑工程学院,江苏徐州221116

出　　处：《煤炭学报》2013年第7期1143-1148,共6页Journal of China Coal Society

基　　金：国家自然科学基金面上资助项目(41171065);上海市科学技术委员会科研计划资助项目(10231200400)

摘　　要：为获得液氮冻结管内沸腾段的分布特征,采用在供液管上开孔的冻结管结构,进行了现场冻结试验,通过布置在冻结管内的测温管,测试了液氮冻结过程中冻结管内的温度,获得了冻结管内沸腾段的分布特征,得出以下基本结论:采用供液管上开孔的冻结管结构,冻结管内出现液氮沸腾状态时,冻结管出口氮气温度较传统液氮冻结的出口温度低。随着液氮灌注量的增加,在供液管开孔段上部位置首先出现液氮沸腾段,并逐渐向下延伸,直至下部冻结管全部进入沸腾段,而上部未开孔的范围内较难获得液氮沸腾状态。由于不同位置液氮气化量的差异,造成液氮沸腾段内形成的冻结壁均匀性较差。研究结果表明,调节供液管上的开孔范围和液氮供应量,可以有效控制冻结管内沸腾段分布范围,提高液氮利用效率,发挥液氮快速冻结的优势。In order to obtain distribution characteristics of liquid nitrogen boiling sections in freezing pipe, an insitu liquid nitrogen freezing experiment was carried out in this study. There are opened holes on the liquid nitrogen suppl ying tube. The temperature and distribution of liquid nitrogen boiling sections can be obtained through the temperature measuring tube installed inside the freezing pipe. The study shows that firstly, the export temperature of the freezing pipe with openingholes on supplying tube is lower than that of traditional pipe when liquid nitrogen boiling sections appear in the freezing pipe. Secondly, with the increase of liquid nitrogen perfusion, liquid nitrogen boiling sections ap pear initially on the top of openingholes supply pipe, and gradually extend down the pipe. It is difficult to obtain the boiling situation on the sections with no openedholes in the upper freezing pipe. Thirdly, the frozen wall is nonuni form because of the amount difference of liquid nitrogen gasification in different positions. The test results show that the adjustment on the openholes sections of the supply pipe and the amount of liquid nitrogen supply can effectively de termine the distribution characteristics of the liquid nitrogen boiling sections. The adjustment of liquid nitrogen boiling sections, which may improve the efficiency in liquid nitrogen usage, can enhance the rapid freezing.

关 键 词：液氮冻结 液氮沸腾段 冻结管结构 温度分布 原型试验 

分 类 号：TD265.3[矿业工程—矿井建设]