西安科技大学学报2026，Vol.46Issue(3)：543-552,10.DOI:10.13800/j.cnki.xakjdxxb.2026.0307
羧基化MWCNT强化重力热管煤火移热研究
Study on enhanced coal fire heat extraction using carboxylated MWCNT nanofluid as the working fluid in gravity heat pipes
摘要
Abstract
To improve the efficiency of the gravity heat pipe(TPCT)in extracting low-grade thermal energy from coal fire areas,carboxylated multi-walled carbon nanotubes(MWCNTs-COOH)were pre-pared by a mixed-acid liquid-phase oxidation method,and MWCNTs-COOH nanofluids were then pre-pared using a two-step method.Thermogravimetric analysis was conducted to evaluate the thermal sta-bility of the vacuum-dried nanofluids.Combined with zeta potential,contact angle,and thermal conduc-tivity tests,their dispersion stability,interfacial wettability,and thermal conductivity were systematically investigated.In addition,a self-built coal fire heat extraction test platform was used to analyze the tem-perature field distribution and heat transfer characteristics during thermal energy extraction.The results show that the MWCNTs-COOH nanofluid has excellent thermal stability,with a mass residual rate of up to 92%.The dispersion stability and thermal conductivity of the modified multi-walled carbon nano-tubes are significantly improved.The zeta potential of the carboxylated nanofluid reaches 45 mV,the contact angle is about 69°,and the increase in thermal conductivity rises steadily from 4.04%at 20℃to 4.32%at 100℃.Under a coal temperature field of 100℃,the maximum temperature reduction of the TPCT using the MWCNTs-COOH working fluid is 40.2℃,significantly higher than the 29.9℃obtained with the MWCNT working fluid,corresponding to a 24%improvement.The cumulative heat extraction of the TPCT using the MWCNTs-COOH working fluid over 24 h reaches 322.4 MJ,about 38.42%higher than the 232.9 MJ obtained with the MWCNT working fluid.These results provide a theoretical basis for engineering design and analysis of clean and efficient utilization of thermal energy from coal fires.关键词
煤火/重力热管/羧基化多壁碳纳米管/纳米流体/热能提取Key words
coal fire/gravity heat pipe/MWCNTs-COOH/nanofluid/thermal energy extraction分类
资源环境引用本文复制引用
张玉涛,柏可心,杨杰,李亚清,田皓天,Saeid Zeinali Heris..羧基化MWCNT强化重力热管煤火移热研究[J].西安科技大学学报,2026,46(3):543-552,10.基金项目
国家自然科学基金项目(52174196) （52174196）
陕西省杰出青年科学基金项目(2025JC-JCQN-024) （2025JC-JCQN-024）
