土壤热物性测试方法与影响因素分析研究

发布时间：2018-07-04 09:19

  本文选题：土壤源热泵 + 热物性参数　； 参考：《湖南大学》2014年硕士论文

【摘要】：土壤源热泵空调系统作为一种绿色节能、低碳环保的空调系统形式在建筑领域的应用已经越来越普遍。地埋管换热器设计是土壤源热泵设计的关键步骤，，准确的测试出工程所在地岩土热物性参数是地埋管换热器设计的前提与保证。本文针对土壤热物性测试的相关问题，主要就以下几个方面进行了一系列的分析研究。 首先，本文对岩土热物性的测试方法与数据处理方式进行了比较分析，总结出了一种适用于工程运用的推荐方法。这种方法建立在热响应测试的基础上，先计算出岩土综合导热系数，再利用双参数估计法计算出钻孔内热阻以及岩土热扩散系数。 其次，针对本文推荐的岩土热物性参数计算方法，对可能引起测试误差的各个因素进行了分析。研究得出初始地温测试偏差0.5℃，钻孔内热阻的偏差会达到6.5%，钻孔夏季单位管长换热量平均偏差2.5%，冬季单位管长换热量平均偏差7.5%。岩土综合导热系数随加热功率测量值增大而增大，加热功率测量值每偏差100W，钻孔内热阻平均减小0.01m k/W，钻孔夏季单位管长换热量偏差约为1.9%，钻孔冬季单位管长换热量偏差为2.0%。另外本文通过对不同测试时间长度测试数据的计算，推荐在实际工程中测试时间长度不小于36个小时。 此外针对传统的测试结果表达方式，本文引入了矩形波阶跃负荷与叠加原理，并验证了这一换热模型的准确性。结合这一换热模型本文提出了一种将热物性参数直接运用于地埋管换热器长度设计的公式。 最后本文研究了测试过程中断电现象，作者运用参数估计法，在矩形波阶跃负荷和叠加原理组合而成的换热模型的基础上，忽略等待过程直接重新测量。用这种方法计算出了测试井断电情况下的岩土热物性参数，并对此方法进行了验证。本文认为这种方法计算出来的岩土热物性参数能满足工程精度要求，很具有实际意义与实用价值。
[Abstract]:As a kind of green energy saving, low carbon environmental protection air conditioning system, the application of ground source heat pump air conditioning system in the field of construction has become more and more common. The design of ground buried tube heat exchanger is a key step in the design of ground source heat pump. It is the premise and guarantee of the design of ground buried tube heat exchanger to accurately test the geotechnical thermal properties of the site of the project. In this paper, a series of analysis and research on the following aspects were carried out in order to solve the related problems of soil thermal properties test. Firstly, this paper compares and analyzes the methods of testing and data processing of geotechnical thermal properties, and summarizes a recommended method for engineering application. Based on the test of thermal response, the comprehensive thermal conductivity of rock and soil is calculated firstly, and then the thermal resistance and thermal diffusion coefficient of rock and soil are calculated by using the method of two-parameter estimation. Secondly, the factors which may cause the measurement error are analyzed according to the calculation method of the geotechnical thermal physical parameters recommended in this paper. The results show that the deviation of thermal resistance in borehole reaches 6.5 when the initial deviation of ground temperature is 0.5 鈩

本文编号：2095593