论文总字数：23027字

摘 要

浅层地热能是一种可以加以利用的资源，尤其是在冬季，浅层地热可以通过一定的技术手段提取出来用于道路的融冰化雪、建筑供暖等。由于热管的极佳的导热性能，使得其可以用来实现地热能的提取。传统的超长重力热管已经开始应用在此领域中，但是其本身存在工质流动阻力大，液池较深等问题严重影响了热管在提取浅层地热能时的传热效果。同时，由于结构原因，使得超长重力热管的加工运输困难；制造成本高。本文研制了一种超长柔性重力热管，该热管克服了传统的超长重力热管的结构缺陷，可以十分简便的组装加工，减少了制造过程中的成本。在验证该热管是否能够有效的实现地热能的采集时，本文首先根据冷凝段的散热量初步估算了该热管的传热功率，验证计算充液量、蒸汽腔直径、管壁厚度、传热极限后，该热管完全符合设计要求。将加工完成的32m的超长柔性重力热管，竖直埋在在一个60m深的钻孔中，露出地面部分的2m长度为冷凝段，蒸发段长30m。将热管各部位安装热电偶，并在2018年的12月份至2019年3月份期间，收集了各部位的温度数据，绘制成折线图。实验表明：在12月份至2月初气温较低尤其在雪天下，蒸发段平均温度与冷凝段未保温处的温度差在12℃左右，其冷凝段温度与空气温度的差值可以始终保持在6℃以上，因此该热管在此时间段下能够十分有效的提取地热能，在3月份气温开始回升时，在中午的室外气温高于蒸发段的温度使得热管暂时停止了工作，此时间段热管只在早晚工作。因此综合实验数据来看，该超长柔性超长重力热管在冬季能够十分有效的提取地热。但其工作受环境影响较大，不具有良好的稳定性，且工作时间十分有限。

关键词：重力热管 超长 柔性 浅层地热能

Absrtact

Shallow geothermal energy is a kind of resource that can be used, especially in winter, shallow geothermal energy can be extracted by certain technical means for road melting snow, building heating and so on. Because of its excellent thermal conductivity, heat pipe can be used to extract geothermal energy. The traditional super-long gravity heat pipe has been used in this field, but its own problems, such as large flow resistance of working fluid and deep liquid pool, seriously affect the heat transfer effect of heat pipe when extracting shallow geothermal energy. At the same time, due to structural reasons, the processing and transportation of ultra-long gravity heat pipe is difficult and the manufacturing cost is high. In this paper, an ultra-long flexible gravity has been developed. The heat pipe, which overcomes the structural defects of the traditional gravity heat pipe, can be easily assembled and processed, and the cost in the manufacturing process can be reduced. In order to verify whether the heat pipe can effectively realize the collection of geothermal energy, this paper first estimates the heat transfer power of the heat pipe which should reach 600W according to the heat dissipation of the condensation section, verifies and calculates the liquid filling, the diameter of the steam cavity and the thickness of the pipe wall. After the heat transfer limit, the heat pipe fully meets the design requirements. The processed 32m flexible gravity heat pipe is buried vertically in a 60m vertical hole. The length of 2m exposed to the ground is the condensation section and the evaporation section is 20 m. Thermocouples were installed in all parts of the heat pipe, and from December 2018 to April 2019, the temperature data of each part were collected and drawn into a broken line diagram. The experimental results show that when the temperature is low from December to early February, the average temperature difference between the evaporation section and the condensation section is about 10 ℃, especially in the rain and snow weather, the maximum temperature difference between the two ends can even reach 12 ℃. Therefore, the heat pipe can extract geothermal energy very effectively under this time period. When

The temperature began to rise in March, the outdoor temperature at noon was higher than the temperature in the evaporation section, so that the heat pipe temporarily stopped working.It only work morning and night. Therefore, according to the experimental data, the ultra-long flexible gravity heat pipe can extract geothermal energy very effectively in winter.However, its work is greatly affected by the environment,and it does not have good stability.The working time is very limited.

Key words: gravity heat pipe ; super long ; flexible ; shallow geothermal energy

目 录

第一章 绪论 5

1.1课题的研究背景及意义 5

1.2超长重力热管的工作原理 6

1.3超长热管的强化传热研究及应用现状 7

1.3.1超长热管的强化传热研究 7

1.3.2超长热管技术对于地热能采集应用 8

1.3.3超长热管技术维持地下低温的应用 8

1.3.4超长热管技术在石油矿业工程中的应用 9

1.4本课题的研究内容 10

第二章 超长重力热管的基本设计 11

2.1超长重力热管的传热机理 11

2.1.1冷凝段传热 11

2.1.2蒸发段传热 12

2.2超长重力热管的设计 13

2.2.1热管工质与管体材料的选取 13

2.2.2超长重力热管的基本尺寸 14

2.2.3超长重力热管的传热极限 15

2.3超长重力热管的制造 18

2.3.1工艺简介 18

2.3.2超长重力热管的制造流程 18

第三章 超长柔性重力热管传热性能的实验研究 21

3.1实验前期准备工作 21

3.2热管在不同月份下工作温度 23

3.3特殊天气下热管工作温度 29

3.4热管的传热性能分析 32

3.4.1蒸发段传热性能分析 32

3.4.2冷凝段传热性能分析 33

3.5本章小结 33

第四章 结论与展望 35

4.1结论 35

4.2展望 35

参考文献 37

致谢 39

第一章 绪论

1.1课题的研究背景及意义

随着能源危机、气候变化等问题的出现，如何取得能源利用效率的最大化；有效利用可再生在能源，是目前急切需要解决的问题。

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