以深部矿井降温系统管道内壁出现的结垢问题为研究对象,首先采集管道水样进行水质全分析测试,确定管道内成垢性离子并建立化学及数学模型,其次采用第一性原理计算方法研究得到了深部矿井降温系统管道结垢微观机理。结果表明,深井降温系统管道内壁结垢过程包括Ca~(2+)和CO_3~(2-)的结合结晶及MgCO_3、CaSO_4转化为CaCO_3的转化;理论分析及第一性原理计算结果表明,深井降温系统管道内壁结垢的主要影响因素为成垢性离子(Ca~(2+)、HCO~-_3、Mg~(2+)和SO~(2-)_4,且Mg~(2+)和SO~(2-)_4的存在会抑制碳酸钙结垢的产生。该研究对于深部高温热害矿井的降温系统的结垢产生机制以及采取合理的防、除垢措施,保障良好的矿井降温效果和安全生产具有理论指导意义。
The micro-mechanism of the scaling of pipelines in the cooling system under deep mine was studied. Firstly, the composition and content of the ions in the mining water were determined by the full analysis of water quality, and then the chemical model and mathematical model were built, finally, the adsorption of scaling ions on iron surface was calculated by using the VASP software based on density functional theory( DFT). The result shows that, 1 the scaling of the cooling system includes the combination of Ca~(2+) and CO_3~(2-) and the transform of MgCO_3, CaSO_4 to CaCO_3; 2 the scaling ions(Ca~(2+), HCO~-_3, Mg~(2+) and SO~(2-)_4) are the main factors leading to the scaling of the cooling system pipelines under deep coal mine and Mg~(2+) and SO~(2-)_4 could restrain the CaCO_3 scaling. The research is of great importance to the understanding of the scaling of the cooling under deep coal mine, pretreatment, and descaling, in order to guarantee the cooling effect and production safety for the geothermal engineering.