川藏公路热冻链接技术及在隧道洞口段融雪除冰应用

Hot-freeze Link Technology and Its Application in Snow Melting and Deicing of Tunnel Portal Section of Sichuan-Tibet Highway

为有效利用川藏公路行经青藏高原断裂带区域内的地热水资源,建立热冻链接技术解决寒区隧道洞口范围内路面融雪除冰问题,文章依托雀儿山隧道出口,采用地质背景调查和现场试验方式,分析了地热水的成因、特征,在温泉水温度、流速、流量现场测试基础上计算了温泉水供热量,同时计算了路面融雪和除冰需热量,分析了热冻链接可行性及现场实际应用效果。研究表明:受青藏高原气候和地形地貌影响,洞口路面大于10 cm厚积雪累计时间180 d,暗冰时间为210 d;受青藏高原地质构造作用及北部断裂带主控,雀儿山隧道隧址区温泉群月供热量理论计算在7.627×10^7~1.320×10^8 kJ;利用Chapman模型和混凝土热交换管内流体传热模型进行计算,为满足隧道洞口段100 m长、8 m宽路面的融雪和除冰要求,月需热量为3.3×10^6 kJ及8.25×10^7 kJ;温泉水按60%利用率计算,依然能完全满足最冷月路面融雪除冰需求;利用温泉水建立热冻链接技术,温泉水热储量丰富,利用高差能保证流量、流速进而省去了泵送设备、节约了电能,余水温度高还可再利用,现场温度测试和计算表明路面融雪除冰实际应用效果良好。

In order to effectively utilize the geothermal water in the fault zone of Qinghai-Tibet plateau passed by Sichuan-Tibet highway,a heat-freeze link technology is developed to deal with snow melting and ice removal of the road surface within the scope of tunnel portal in cold area.Taking the Chola Shan tunnel as the engineering back⁃ground,a geological investigation and field test are conducted to analyze the causes and characteristics of the geo⁃thermal water,the heating capacity of hot spring water is calculated based on the field tests of the temperature,veloci⁃ty and flow of the hot spring water.Meanwhile,the heat demand for snow melting and deicing is calculated,and the feasibility of the hot-freeze link and its practical application effect are analyzed.The results show that:the accumu⁃lated time of snow over 10 cm thick on the road at tunnel entrance is 180 days and the time of dark ice is 210 days due to the effect of climate and topography of the Qinghai-Tibet Plateau.Controlled by the geological tectonism of the Qinghai-Tibet plateau and the northern fault zone,the theoretical calculation of the monthly heat supply capaci⁃ty of the hot spring group in the tunnel site area of Chola Shan tunnel is 7.627×10^7-1.320×10^8 kJ.With Chapman model and heat-transfer model of fluid in heat exchange pipe of concrete,a calculation is conducted,and the month⁃ly required heat supply capacity is 3.3×10^6 kJ and 8.25×10^7 kJ respectively in order to meet the requirements of snow melt and deicing of the 100 m long and 8 m wide road surface at the tunnel entrance;in the case of 60%utili⁃zation rate,hot spring water can still fully meet the needs of snow melting and deicing in the coldest month;hotfreeze link technology is developed by using hot spring water,hot spring water is rich in heat reserves and the height difference can ensure the flow and flow rate,thus pumping equipment is unnecessary and electric energy is saved,and the remained water can be reused due to high temperature.The field temperature test shows that the actual ap⁃plication effect of road snow melting and deicing is good.