面向寒区路基工程的太阳能集热管的设计与试验

针对季节性冻土区路基工程广泛面临的冻胀病害，提出引入一种更具主动性的新型防治方法-太阳能光热技术。应用思路为，通过太阳能光热装置为路基提供一个外部热源，主动地调节路基热量收支关系，有效地控制路基在冬季的过度热量损失，进而消除负温状态和冻胀现象。太阳能等可再生热源的资源性条件与技术性条件在面向路基工程时具有良好的适用性。中国季节性冻土与太阳能分布在地理位置上具有较好的重合性，相比人居环境和工业应用领域，太阳能光热技术在寒区路基工程中更具应用优势。基于太阳能光热技术对比和路基供热的特殊要求，设计与制作一款面向路基工程的专用太阳能集热管。该装置结构型式为立式柱状，分为地表太阳能集热段和路基供热段两部分，前者采用玻璃-金属封接式真空集热管。装置集热段与供热段通过法兰实现直通式连接，可以自主完成太阳能的搜集、储存和传递，自成一体化热量转化单元。太阳能集热管的工作模式为在暖季高效地向路基预先储备热量和在冷季实时地补充热量，全年处于供热状态。太阳能集热管的性能试验表明，集热温度随太阳辐射强度的增大而升高，在冬季辐射良好的条件下集热温度相比大气温度高出10℃以上，起到有利的“热源”作用。太阳能集热管具有主动供热的技术优势，可以为寒区路基防冻胀问题提供一种新方法。

Design and experiment on a solar heat-supplying tube against frost damage of embankment in cold regions

In order to improve the wide-spread frost heave damage of subgrade in seasonally frozen soil regions, a more active thermal measure called solar photothermal technology was introduced. The application idea is to provide an external heat source by the solar photothermal technology, and to adjust the heat input and output of subgrade. Through the above active regulation, the excessive heat loss of subgrade will be controlled, and then the negative temperature and frost heave will be eliminated effectively and timely. The resource and technical conditions of renewable heat sources such as solar energy have good applicability in subgrade engineering. In China, the seasonally frozen soil and solar energy coincide well in geographical distribution. Compared with architectural and industrial applications, solar thermal technology has more advantages in subgrade engineering. Regarding to the differences of photothermal devices and special requirements of subgrade heating, a type of solar heat-supplying apparatus for subgrade was designed and manufactured. Its structure layout is vertical columnar tube, and it mainly consists of the solar heat-collecting section and the subgrade heat-supplying section, the former one adopts glass-metal sealing vacuum tube. These two sections were connected directly by flanges, and act as an integrated heat conversion unit to realize the collection, storage and delivery of solar energy autonomously. Its operation mode is to supply heat for subgrade during the whole year, i.e., to store heat previously in warm season and to compensate heat loss timely in cold season. The performance test show that the heating temperature increases with solar radiation intensity, and can be 10℃ higher than the atmospheric temperature in winter, thus it acts as a favorable “heat source” role. The solar heat-supplying tube belongs to a new type of active thermal technology for subgrade engineering in cold regions.