寒区隧道阳光棚温升效果与影响

Temperature Rise Effects and Impact of Solar Shed in Cold Region Tunnels

为避免寒区隧道冻害问题产生,引入新型阳光棚防寒措施.首先,建立三维瞬态传热数值模型,获得自然通风条件下的隧道温度场,并通过现场温度监测验证数值计算模型的可靠性;然后,通过数值方法验证阳光棚的温升效果,并进一步探究阳光棚入口风速、长度、跨度及环境温度对温升效果的影响;最后,对各因素进行敏感性分析,研究其对温升效果的影响程度.研究结果表明:入口风速低于1.0 m/s时,阳光棚发挥良好的温升效果.风速与温升效果呈负相关;长度每延长50 m,隧道进口气温升高0.71℃;跨度对温升效果的影响不明显;温升效果随环境温度变低而愈显著.上述因素对温升效果的敏感性排序为:入口风速(0.39)>长度(0.30)>环境温度(0.19)>跨度(0.12),其中,入口风速为最敏感因素,应用时应着重考虑.因此,对阳光棚的使用建议为:低风速、大长度、小跨度.

To avoid frost damage problems in cold regions tunnels,a solar shed was introduced as one of the insulation measures.First,a three-dimensional transient heat transfer numerical model was established to obtain the tunnel temperature field under natural ventilation,and the reliability of the numerical calculation model was verified through on-site temperature monitoring.Then,the temperature rise effects of the solar shed were demonstrated through numerical methods,and the effects of the solar shed’s speed,length,span,and ambient temperature on the temperature rise effects were further investigated.Finally,a sensitivity analysis was conducted on these factors to study their impact on temperature rise.The study results show that the solar shed has a good temperature rise effect when the wind speed is lower than 1.0 m/s.The wind speed was negatively related to the temperature rise effects.The air temperature at the tunnel entrance increases by 0.71℃for every 50 m increase in length.The influence of the span on temperature rise effects is not obvious.The temperature rise effects become more and more significant as the ambient temperature becomes lower.The sensitivity of the above factors to temperature rise effects is ranked as follows:wind speed(0.39)>length(0.30)>ambient temperature(0.19)>span(0.12),of which the wind speed is the most sensitive factor and should be considered in the application.Therefore,the recommendation for the use of a solar shed is in environments with low wind speed,long tunnel lengths and small tunnel spans.