面向路基冻胀的地源热泵装置的设计与试验

Design and experiment on a ground-source heat pump apparatus against frost damage of embankment

针对中国季节性冻土区路基工程广泛存在的冻胀现象,通过路基工程与供热工程的学科交叉分析,提出将地源热泵技术引入路基工程。供热技术应用于路基工程的理念在于,在冬季通过人工热源主动地向路基输入热量,来实时地补偿热量损失,进而消除路基负温状态和冻胀现象。设计与制作一款面向路基工程的专用地源热泵装置,工作原理为蒸气压缩式热力学循环,换热方式为直接膨胀式,通过制冷剂的蒸发、压缩和冷凝实现地热能的搜集、品位提升和释放。该装置自成独立的制热单元,主要包括地表驱动部件和地层换热部件,前者包括压缩机、毛细管、控制器等;后者包括稳定地层集热段和冻胀地层供热段,结构型式为立式柱状。装置供热试验表明,供热温度可达50℃以上,集热温度可达?8℃以下,有效供热半径在1.4m以上。地源热泵装置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。

In order to improve the widespread frost heave damage of subgrade in China,the ground-source heat pump technology was introduced to subgrade engineering,based on the cross analysis with heat-supply engineering.The idea lies in that the additional heat can be imported to subgrade timely in winter by an external heat source,and compensate the excessive heat loss,thus eliminating the negative temperature and frost heave.The different types of heat sources were first compared,and the heat-supply technical requirements for subgrade were also summarized.A new type of frost heave prevention device called'ground-source heat pump(GSHP)'apparatus was designed and manufactured.Its operation principle is vapor compression thermodynamic cycle,and its heat transfer mode is direct-expansion.The GSHP apparatus can realize the collection,concentration and release of geothermal energy by the direct evaporation,compression and condensation of the refrigerants correspondingly.The GSHP apparatus is an independent system,and contains the driving components on the surface and the heat-transfer components in the stratum.The driving components includes compressor,throttle device and controller et al.The heat-transfer components are in columnar type,and consist of the heat-collecting section in stable stratum and the heat-supplying section in frost heave stratum.The performance test showed that the heating temperature of GSHP is above 50℃and the refrigeration temperature can be below?8℃,and its heating radius is above 1.4 m.The GSHP apparatus belongs to a new type of active temperature-control technology for subgrade engineering in cold regions.