摘要:
液氧爆破是一种利用快速相变和体积膨胀效应产生高压气体以实现岩石破碎的新型气体致裂技术。针对液氧相变爆破核心机理不明确、膨胀过程不清晰、吸收剂材料的影响机制不可控等特点,开展了不同吸收剂材料的液氧药包爆破全过程研究。构建了液氧药包爆破实验系统,采用高速相机对不同吸收剂液氧药包爆破实验进行跟踪拍摄。通过图片处理软件对药包点燃至完全起爆时间的差异以及爆破过程进行了分析。结果表明:不同吸收剂材料的结构特征及其燃烧特性对液氧爆破全过程具有决定性作用,具体表现为:纤维状吸收剂因液氧存储能力弱且燃烧速率慢,导致起爆时间延迟并产生爆后残留物二次燃烧;颗粒状吸收剂因其高比表面积实现了液氧高效吸附与充分燃烧,显著缩短起爆时间且无爆后残留;通过调控吸收剂微观结构能够改变液氧固定方式—燃烧速率—能量释放的协同关系。并且,首次通过高速影像捕捉到源于吸收剂燃烧速率与药包结构共同影响下的非对称能量释放药包位移现象,并结合现场实际工程中冲孔现象进行对比分析。未来研究可进一步探索燃烧速率适中、固定液氧能力强、经济成本较低的新型吸收剂材料,以优化液氧爆破的实际应用,提高其工程安全性和适用性。
关键词:
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液氧爆破 /
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吸收剂 /
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高速影像 /
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能量释放 /
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冲孔
Abstract:
Liquid oxygen (LOX) blasting is a novel gas-based rock fracturing technology that relies on rapid phase transition and volumetric expansion to generate high-pressure gas for rock breakage. To address the unclear mechanisms of LOX phase transition, the poorly understood expansion process, and the uncontrollable effects of absorbent materials, this study investigates the complete explosion process of LOX charges with various absorbents. An experimental setup was developed, and high-speed imaging was employed to track the explosion behavior of LOX charges using different absorbent materials. Video data were processed to analyze the ignition-to-detonation time and critical explosion stages. The results demonstrate that the structural and combustion characteristics of absorbents play a decisive role in the LOX explosion process. Fibrous absorbents, due to limited LOX retention and slow combustion rates, cause delayed ignition and post-blast secondary combustion. In contrast, granular absorbents—with higher specific surface areas—enable efficient LOX absorption and complete combustion, significantly reducing ignition time and leaving no residue. Regulating the microstructure of absorbents can effectively adjust the coupling among LOX fixation, combustion rate, and energy release. For the first time, high-speed imaging captured asymmetric charge displacement induced by the combined effect of absorbent combustion rate and charge structure, which is compared to punching phenomena observed in field-scale blasting. Future studies should focus on developing new absorbents with moderate combustion rates, strong LOX retention capacity, and low cost to enhance the safety, efficiency, and engineering applicability of LOX blasting.