地埋管换热器周围土壤热恢复特性研究

发布时间：2018-03-30 12:29

  本文选题：土壤源热泵　切入点：地埋管换热器　出处：《青岛理工大学》2013年硕士论文

【摘要】：近年来，土壤源热泵由于其节能、环保、高效等优点，得到越来越广泛的应用。然而随着土壤源热泵运行时间的延续，由冷热负荷不平衡及土壤温度不能及时恢复而造成的热堆积对热泵系统的影响越来越显著，甚至导致部分热泵系统失去运行能力。因此，本文对土壤热恢复特性进行了研究，主要工作如下： 1、建立单井及井群的有限元传热模型，并结合已测得的实验数据，分别对夏季和过渡季（秋季）的土壤温度变化进行对比分析，，发现夏季实测值和模拟值的最大相对误差为11%，平均相对误差为3%；过渡季（秋季）最大相对误差为0.12%，验证模型的正确性。 2、利用实验台进行了连续三年的实验测试。研究发现，实验工况输入土壤的累计冷热负荷不平衡率达到73%，而运行两年之后土壤温度仅降低了0.6℃，管壁处土壤热恢复的主要时期为春秋过渡季节。第三年停机一年后土壤温度基本恢复至初始温度。 3、利用建立的传热模型，分别分析了土壤导热系数、密度、比热、导温系数、间歇运行和延米换热量对土壤热恢复特性的影响，发现土壤的导温系数和导热系数是影响土壤热恢复特性的关键因素，土壤的密度、比热、间歇运行工况和延米换热量都对土壤的热恢复具有一定的影响。 4、利用井群模型分析了连续运行和间歇运行工况砂岩土质时井群的热恢复特性，得到了在两种工况下砂岩的土壤温度可恢复范围。 本文的研究有助于解决土壤热恢复的问题，提供不同运行模式下土壤温度可恢复范围，为土壤源热泵系统的设计提供一定的参考。
[Abstract]:In recent years, ground source heat pump (GSHP) has been more and more widely used because of its advantages of energy saving, environmental protection, high efficiency and so on. The heat accumulation caused by the imbalance of cold and heat load and the inability of soil temperature to recover in time have more and more significant effects on the heat pump system, and even lead to the loss of operation capacity of some heat pump systems. Therefore, the characteristics of soil thermal recovery are studied in this paper. The main tasks are as follows:. 1. The finite element heat transfer model of single well and well group is established, and the soil temperature changes in summer and transition season (autumn) are compared and analyzed by combining the measured experimental data. It is found that the maximum relative error between the measured value and the simulated value in summer is 11, the average relative error is 3, and the maximum relative error in the transition season (autumn) is 0.12, which verifies the correctness of the model. 2. Three consecutive years of experimental tests were carried out on the experimental bench. It was found that the unbalance rate of the accumulated heat and cold load in the input soil under the experimental conditions reached 73%, but the soil temperature decreased only 0.6 鈩

本文编号：1685914