基于能源桩的城市隧道路面融雪防结冰技术探究

Exploration of Deicing Technology for Urban Tunnel Pavements Using Geothermal Energy Piles

为解决传统融雪除冰方式效率低、后处理、融雪不彻底甚至存在污染的难点,研究地下工程浅层地热利用技术,提出利用隧道桩提取浅层地热能进行路面防结冰的系统原理及运行理论。结合清凉门隧道工程进行城市隧道地热防结冰系统的设计,通过数值模拟分析系统换热性能、路面下埋管的力学特性以及系统运行效果。结果表明:1)利用隧道桩埋管换热能够满足隧道敞开段路面冬季的防结冰需求;2)在换热管下部采取相应的隔温措施,能够有效地降低路面下的拉压应力,同时还能够降低热量向路基下方的热损失,提高能源利用效率;3)在南京地区,相比于碳纤维电缆加热法防结冰技术,城市隧道桩基础地热防结冰技术每年能够节省约60%的运营电费,节能效果显著。

The traditional deicing methods have many disadvantages such as low efficiency,need for postprocessing,incomplete melting,and pollution risk.Accordingly,the application of shallow geothermal energy in underground engineering construction is analyzed,and the system principle and the operation theory of the pavement deicing technology by extracting shallow geothermal energy through energy piles is introduced.Then,a specific design of the Qingliangmen tunnel deicing project is proposed.The system heat transfer performance,mechanical characteristics of the buried pipe under the pavement,and the system operation effect are analyzed by a numerical modeling method.The results show the following:(1)The antifreeze requirement of the pavement in the open section of the tunnel is satisfied by using energy piles in winters.(2)By adopting insulation measures in the lower part of the heat transfer tube,the tensile stress of the concrete structure under the pavement and the heat loss when transferring to the road foundation are reduced,thereby improving energy efficiency.(3)Compared with the deicing technology based on the carbon-fiber-cable heating method,the electricity consumption per year of the deicing technology based on geothermal energy piles is less by 60%,which indicates a good energy-saving effect.