Modeling effective heat transfer and ventilation in deeply buried underground tunnels
Modeling effective heat transfer and ventilation in deeply buried underground tunnels
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DOI：
10.1016/j.ijthermalsci.2022.107949
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发表时间：
2023
影响因子：
4.5
通讯作者：
Jinnan Guo;Angui Li;Chi Zhang;Jiaxing Li;Jigang Che;Jing Xiong;Xinqi Jiao
中科院分区：
文献类型：
--
作者：
Jinnan Guo;Angui Li;Chi Zhang;Jiaxing Li;Jigang Che;Jing Xiong;Xinqi Jiao
地下交通隧道作为地下空间建筑物的出入口。地下空间的通风空调系统大多依靠交通隧道进行冷却或预热以节省能源。为了分析交通隧道的冷却或预热性能，结合能量守恒定律、边界层理论和现场测量，建立了深埋地下隧道在光滑和粗糙条件下的简单传热模型。此外，采用无量纲分析方法对结果进行无量纲分析。现场测试发现，交通隧道入口处的气温随时间在20.2℃至29.4℃之间呈谐波波动。沿隧道波动幅度逐渐减小，出口处气温峰谷差仅为1.2℃。夏季，白天和夜间隧道沿线气温分别呈指数下降和上升，从 29.4°C 到 23.4°C，从 20.2°C 到 22.2°C。光滑、粗糙和测试条件下的对流换热系数分别为 2.31 W m−2K−1、4.05 W m−2K−1 和 3.32 W m−2K−1。对气温进行无量纲化发现，建立的模型很好地描述了气温的指数衰减。结合传热模型，有效传热分析表明，地下交通隧道的有效传热长度为1545 m，最佳传热长度为628 m。建立计算地下交通隧道温度分布的传热模型，为地下交通隧道作为天然空调提供了重要的理论支撑，具有重要的经济效益和环境效益。
Underground traffic tunnels serve as entry and exit buildings for structures underground spaces. Most ventilation and air-conditioning systems in underground spaces rely on traffic tunnels for cooling or preheating to save energy. To analyze the cooling or preheating performance of the traffic tunnel, a combination of the energy conservation law, boundary layer theory, and field measurement was used to establish a simple heat transfer model of the deeply buried underground tunnel for smooth and rough conditions. Moreover, the dimensionless analysis method was used to perform a dimensionless analysis of the results. Field tests found that the air temperature in the traffic tunnel harmonically fluctuates from 20.2 °C to 29.4 °C at the entrance with time. The fluctuation amplitude decreases along the tunnel, and the air temperature difference between the peaks and troughs is only 1.2 °C at the outlet. In summer, the air temperature decreases and increases exponentially from 29.4 °C to 23.4 °C and from 20.2 °C to 22.2 °C along the tunnel during the day and night, respectively. The convective heat transfer coefficients are 2.31 W m−2K−1, 4.05 W m−2K−1, and 3.32 W m−2K−1under smooth, rough, and test conditions, respectively. Dimensionlessizing the air temperature found that the established model is a good description of the exponential decay of air temperature. Combined with the heat transfer models, the effective heat transfer analysis showed that the effective and optimal heat transfer lengths of the underground traffic tunnel were 1545 m and 628 m, respectively. The established the heat transfer model that calculated the temperature distribution of underground traffic tunnels provides important theoretical support for underground traffic tunnels as natural air conditioners, which have important economic and environmental benefits.