摘要
研究目的:为解决季节冻性土区铁路路基冻胀问题,提出一种新型热能转化式路基。通过专用地源热泵系统,收集路基附近地基稳定层的低位地温能,并转化为高位热能,然后传递至路基冻胀层,以实现对路基的主动供热和温度控制,根除冻胀。在准池铁路某冻胀区段,建设1段20 m长的热能转化式路基试验段,在2021—2022年冬季测试热泵供热温度、试验段路基和天然路基的温度场、冻结深度、轨道冻胀量等指标的变化情况。研究结论:(1)热泵供热温度峰值可达59.4℃,间歇运行时的日均供热温度达25.2℃以上,热源品位高,起到有利的热源作用;(2)天然路基冻结期持续141 d,试验段路基相比减小了20 d;试验段轨道中心、路肩及坡脚位置的最大冻结深度分别为88 cm、75 cm、58 cm,相比天然路基分别减少了60 cm、122 cm、78 cm,将冻结深度控制在有害临界值以内;(3)天然条件下轨道冻胀量峰值为9.4 mm,形成有害冻胀;而试验段轨道变形量小于±3 mm,未超出经常保养管理值;(4)热能转化式路基对于低路堤、路堑基床、岔区、涵顶等重要部位的顽固性冻胀病害是一种有效的防控手段。
Research purposes:In order to resolve the frost-heaving problem of railway subgrade in seasonally frozen soil regions,a novel energy conversion subgrade was proposed in this study.To this end,a special ground source heat pump system was installed to collect the low-grade geothermal energy of stability layer of the foundation near the subgrade,and convert it to a high-grade heat source.Then the generated heat was transferred to the frost-heaving layer of the subgrade to realize active heating and temperature control,thereby eliminating the frost-heaving problem.In order to analyze the performance of the proposed system,a 20 meters long geothermal energy conversion subgrade test section was constructed at a frost-heaving site of the Jungar-Shenchi Railway.The heating temperature of the heat pump,temperature field,freezing depth,and track frost-heaving deformation of energy conversion subgrade and natural subgrade during the winter of 2021~2022 were tested and analyzed.Research conclusions:(1)The maximum heating temperature of the heat pump and its average daily heating temperature during intermittent operation can reach 59.4℃and above 25.2℃,respectively.Accordingly,it is concluded that heat pumps can be effectively used as high-grade heat sources.(2)The freezing period of the natural subgrade lasted for 141 days,and the energy conversion subgrade was reduced by 20 days.Moreover,the maximum freezing depth at the track center,subgrade shoulder,and slope toe were 88 cm,75 cm,and 58 cm,respectively.These depths are within the critical value of harmful freezing depth and are 60 cm,122 cm,and 78 cm less than those of natural subgrade,respectively.(3)The peak frost-heaving deformation of the track under natural conditions reached 9.4 mm,which is beyond the acceptable criteria and may lead to harmful results.The obtained results show that the track deformation in the test section was less than±3 mm,which does not exceed the management value of regular maintenance.(4)The performed analyses demonstrate that the energy c
作者
胡田飞
张宗凯
岳祖润
袁一飞
赵李旗
HU Tianfei;ZHANG Zongkai;YUE Zurun;YUAN Yifei;ZHAO Liqi(State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China)
出处
《铁道工程学报》
EI
CSCD
北大核心
2024年第3期17-22,共6页
Journal of Railway Engineering Society
基金
国家自然科学基金资助项目(42001059,52172347)
中央引导地方科技发展资金项目(226Z5402G)
河北省自然科学基金项目(E2020210044)。
关键词
路基冻胀
地温能
热泵
供热温度
温度场
冻结深度
冻胀量
embankment frost heave
geothermal energy
heat pump
heating temperature
temperature field
freezing depth
frost-heaving deformation
