摘要
为了保证青藏铁路的安全运行,在设计施工阶段就要解决维持青藏铁路沿线冻土层的温度恒定的问题.应用热管技术中的低温热管具有高效性、经济性、环保性等特点,经过分析青藏地区的气象资料并进行相关计算,发现热管传热总温差很小,平均10℃左右,且随大气温度的变化而变化.进一步通过理论计算,发现热管传热的总热阻很大,应尽量降低热管本身的热阻和凝结段空气的传热热阻.通过理论计算和试验验证,以氨为工质的冻土热管完全可以适应小温差下的传热环境,它可以将较低的大气温度直接"拉近"到埋入土壤内部的蒸发器表面,实现高效的储冷传热.低温热管不仅可以应用于公路铁路沿线,还可以运用在冻土地区的桥梁、涵洞、输油和输气管线等市政管线,应用前景广阔.
In order to ensure the safety operation course at a constant temperature along the Qinghai of Qinghai-Tibet Railway, we have to maintain the fl＇ozen soil -Tibet Railway in the design and construction periods. According to the high-efficiency, economical and environmentally beneficial characteristics of the low temperature heat pipe （cryogenic heat pipe）, we analyzed and calculated the climatological data in Qinghai and Tibet regions and found that the overall temperature difference in the heat transfer of the heat pipe was small, about IO^C in average, be- sides, the overall temperature difference changed with the variation of atmospheric temperature. Further theoretical calculation showed the overall thermal resistance of the heat pipe is very big, so we should reduce the thermal re- sistance of the heat pipe itself and the heat transfer resistance of the air in the condensation section. The theoretical calculation and experimental test ,prove that the frozen soil heat tube using ammonia as working medium completely adapts to the heat transfer environment in small range of temperature, and directly ＂pulls＂ lower atmospheric tem- perature to the surface of the evaporator which was embedded into the soil, so as to realize high-efficiency cold stor- age and heat transfer. The low temperature heat pipe has wide prospects of application. It can be applied not only in the highway and railway, but also in the municipal pipelines of bridges, culverts, oil and gas transportation lines.
出处
《应用科技》
CAS
2011年第7期52-55,共4页
Applied Science and Technology
基金
中国博士后科学基金资助项目(2010081003)
关键词
低温热管
传热温差
传热热阻
青藏铁路
cryogenic heat pipe
heat transfer temperature difference
heat transfer resistance
Qinghai-Tibet railway
