垂直地埋管管群换热器换热三维数值模拟研究

发布时间：2018-05-10 16:21

本文选题：地源热泵系统 + 垂直U型地埋管　；参考：《沈阳建筑大学》2015年硕士论文

【摘要】：进入21世纪以来,随着地球传统能源的日益紧缺,节能成为人们越来越关注的话题。以高效、节能、环保为主要特点的地源热泵系统收到了越来越多的重视,地源热泵技术也受到了广泛的应用。地下换热器是地源热泵最为关键的组成之一,换热器的换热性能对地源热泵整体效率有至关重要的作用。本文以地下垂直U型地埋管管换热器为研究对象,运用GAMBIT软件建立与实际尺寸相同的垂直U型地埋管三维模型,并运用FLUENT分别对冬夏两季工况下进行数值模拟计算,用双因素耦合法分析各因素对垂直U型地埋管换热器换热性能的影响规律。结果表明：进口流速、进口温度、回填材料导热系数、钻井深度和土壤热物性对垂直U型管换热器换热性能有明显影响,分别分析了各因素对埋管换热性能的影响规律并对造成这种规律的主要原因做出具体分析解释。本文通过模拟分析,对比单、双U型地埋管换热器换热性能发现：各因素对垂直双U型管换热器换热性能的影响规律与垂直单U型管换热器换热性能基本一致。在相同运行工况下,双管的单位井深换热量和单井换热量都高于单管,但双管的进出口温度差比单管的进出口温度差有明显减少。热短路问题是地源热泵系统中普遍存在的问题,也是制约垂直U型地埋管换热器发展的关键因素,本文通过模拟分析各因素对单、双U型管换热器的热短路情况的影响,得出不同因素对热短路的影响大小,为地源热泵工程实践提供参考数据。
[Abstract]:Since the 21 st century, with the increasing shortage of traditional energy, energy conservation has become a topic of more and more concern. More and more attention has been paid to the ground source heat pump (GSHP) system, which is characterized by high efficiency, energy saving and environmental protection. Ground heat exchanger is one of the most important components of ground source heat pump. The heat transfer performance of ground source heat pump plays an important role in the overall efficiency of ground source heat pump. This paper takes the underground vertical U-tube heat exchanger as the research object, uses the GAMBIT software to establish the three-dimensional model of the vertical U-type buried pipe with the same size as the actual size, and carries on the numerical simulation calculation in the winter and summer working conditions with FLUENT, respectively. The influence of various factors on the heat transfer performance of vertical U-type buried tube heat exchangers was analyzed by two-factor coupling method. The results show that the inlet velocity, inlet temperature, heat conductivity of backfill materials, drilling depth and soil thermal properties have obvious effects on the heat transfer performance of vertical U-tube heat exchangers. The influence of various factors on the heat transfer performance of buried pipes is analyzed and the main reasons for this rule are analyzed and explained in detail. Through simulation and analysis, it is found that the influence of various factors on the heat transfer performance of vertical double-U-tube heat exchangers is basically consistent with that of vertical single-U-tube heat exchangers. Under the same operating condition, the heat exchange in unit depth and in single well is higher than that in single pipe, but the difference of inlet and outlet temperature of double pipe is obviously reduced than that of single tube. Thermal short circuit is a common problem in ground source heat pump system and a key factor restricting the development of vertical U-tube heat exchangers. This paper analyzes the influence of various factors on the thermal short circuit of single and double U-tube heat exchangers. The influence of different factors on thermal short circuit is obtained, which provides reference data for ground source heat pump engineering practice.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU831

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