为研究长距离公路隧道电力电缆区在夏季机械通风条件下仍然存在的高温环境问题，以上海市G40长距离跨江隧道为研究对象，采用CFD模拟方法，探究电缆发热量、室外环境温度和通风量对电力电缆区温度场分布的影响规律，并提出适用于该隧道结构的温度预测关联式，用于解决工程实践中面临的“高温区域覆盖范围如何界定”以及“下游温度超标临界条件如何判定”等关键问题。结果表明： 1）在夏季机械排风工况下，电力电缆区的空气温度沿着隧道纵向呈现非线性增长趋势，表明气流驱动的热迁移现象显著； 2）电缆发热量对隧道进排风温差呈现非线性增长特征，当电缆长期高负载运行时，电缆区排风温度将超过标准规定的安全阈值（≤40 ℃）； 3）降低隧道入口温度虽可减少排风温度，但会导致进排风温差扩大超出规范限值（≤10 ℃）； 4）通风量每增大87.81 m3/s（即换气次数增大2次/h）可使排风温度降低约3.57 ℃，但过高的通风量会导致风机功耗激增，因此需要进一步研究通风策略以平衡降温效果与风机能耗之间的关系。
The issue of elevated temperatures in power cable areas of long-distance highway tunnels remains pronounced during summer, even under mechanical ventilation. The authors investigate the Shanghai G40 long-distance cross-river tunnel to evaluate the effects of cable heat generation rate, outdoor ambient temperature, and ventilation rate on the temperature distribution within the cable area using computational fluid dynamics simulation. A temperature prediction correlation applicable to tunnel structures is proposed to address key engineering challenges, including defining the extent of high-temperature zones and determining the critical conditions for downstream temperature exceeding regulatory limits. The findings are as follows: (1) Under summer ventilation conditions, the air temperature in the power cable area increases rapidly along the tunnel′s longitudinal direction, indicating a prominent airflowdriven thermal migration effect. (2) The inlet-outlet temperature difference in the tunnel exhibits nonlinear growth with increasing cable heat generation. During prolonged high-load cable operation, the outlet temperature exceeds the safety threshold of 40 ℃. (3) Lowering the inlet air temperature reduces the outlet temperature but enlarges the inlet-outlet temperature difference beyond the allowable limit of 10 ℃. (4) Increasing the ventilation rate by 87.81 m3/s (equivalent to two air changes per hour) decreases the outlet temperature by approximately 3.57 ℃; however, excessively high ventilation rates substantially increase fan power consumption. Therefore, further research is required to optimize ventilation strategies that balance thermal control and energy efficiency.
