能源桩换热过程中结构响应原位试验研究

发布时间：2018-04-05 13:17

本文选题：地源热泵　切入点：能源桩　出处：《岩土工程学报》2014年06期

【摘要】：目前关于在桩基中埋设换热管作为地源热泵换热器(即所谓"能源桩"技术)在制冷或供暖过程中对结构和周围岩土体的影响的信息十分有限。在河南省信阳市一项地源热工程中开展了保持桩顶加载条件下施加温度荷载并进行桩身结构响应量测的试验。试验持续了4周的时间,在常规静载试验的基础上叠加了温度循环,以模拟能源桩在实际运行时的工况。沿桩身深度方向布设了振弦式应变计和其它量测仪器,获取了桩身的应变和温度曲线剖面。同时获得了桩顶加载量、桩顶位移、桩身中换热管的进出口水温以及环境温度等数据。从这些数据中又推导出桩身的附加温度荷载。在此试验的基础上,又探讨了能源桩结构响应的简化规律。对桩体进行加热或制冷后,桩体中相对于结构加载产生了附加温度荷载(拉力或压力),且受制于桩端和桩周约束,结构荷载和温度改变引起的附加荷载的合力可能会超出桩基设计规范的限值,在能源桩设计中应给予充分的考虑。
[Abstract]:At present, there is limited information about the influence of heat transfer pipe embedded in pile foundation as a ground source heat pump heat exchanger (so-called "energy pile" technology) on structure and surrounding rock and soil in the process of refrigeration or heating.In a geothermal engineering project in Xinyang City Henan Province an experiment was carried out to measure the response of the pile structure under the condition of holding the top of the pile under the loading condition.The test lasted for 4 weeks, and the temperature cycle was superimposed on the basis of the conventional static load test to simulate the working condition of the energy pile in actual operation.A vibrating string strain gauge and other measuring instruments are arranged along the direction of the depth of the pile body. The strain and temperature curves of the pile body are obtained.At the same time, the data of pile top loading, pile top displacement, inlet and outlet water temperature of heat transfer pipe in pile body and ambient temperature are obtained.From these data, the additional temperature load of the pile body is derived.On the basis of this experiment, the simplified law of structural response of energy pile is discussed.When the pile body is heated or cooled, additional temperature load (tension or pressure) is produced in the pile body relative to the structure loading, and it is constrained by the end of the pile and the circumference of the pile.The combined force of additional loads caused by structural load and temperature change may exceed the limit value of the design code of pile foundation, which should be fully considered in the design of energy pile.
【作者单位】：清华大学土木工程系;长江勘测规划设计研究院;
【基金】：清华-剑桥-麻省理工学院三校低碳大学联盟基金项目~~
【分类号】：TU831.6;TU473.1

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