液态CO_2相变致裂的TNT当量研究

Research on TNT equivalent of liquid CO_2 phase-transition fracturing

为确定液态CO2相变致裂爆破影响半径,进而确定合理的装药量和布孔参数,需要研究液态CO2相变致裂的TNT当量。通过分析液态CO2相变致裂原理,选取压缩气体与水蒸气容器爆破模型进行TNT当量计算,然后利用动力分析软件ANSYS_LS-DYNA3D模拟TNT在混凝土试块中的爆炸,分析应力分布情况,并将所得结果与液态CO2相变致裂试验结果对比。研究结果表明:液态CO2相变致裂设备中,F57L型储液管和SD390型定压泄能片单次致裂产生的能量与277 g TNT所具有的能量相当;液态CO2相变致裂试验的破碎分形维数D为2.83,TNT数值模拟的破碎分形维数D为2.41,相对误差约为14.84%,满足工程应用的需要。

In order to determine the blast radius of influence of liquid CO2 phase-transition fracturing, then determine reasonable charge quantity and hole parameters, it is necessary to study the TNT equivalent of liquid CO2 phase transition fracturing. Through the analysis of principle of liquid CO2 phase transition fracturing, the computational model of compressed air and steam vessel explosion＇was selected to calculate the TNT equivalent. By using ANSYS LSDYNA software, same equivalent explosion in a block of concrete was simulated, and stress distribution was analyzed . A comparison was made between the results of the simulation and those of a liquid CO2 phase-transition fracturing test. The results of study show that fractu- ring energy from the equipment of liquid CO2 phase-transforming fracture for F57L liquid storage tube and SD390 rupture disc is equivalent to 277g TNT , that concrete fractal crushing dimension D of liquid CO2 phase-transforming fracture is 2.83, and fractal crushing dimension D of TNT numerical simulation is 2.41 ,and relative error is about 14.84% , which can satisfy the need of engineering application.