论文总字数：52132字

摘 要

太阳能热水系统是目前效率最高、应用规模最大的太阳能光热利用项目。目前市场上全玻璃真空管式太阳能集热器和热管式真空管太阳能集热器占主要地位，然而目前太阳能集热器中广泛采用的是重力热管，传统的重力热管无法水平放置，这就造成了太阳能热水系统与建筑一体化的配合上有很大难度。为了更好地配合建筑节能，本文开发了一种新型的水平热管太阳能集热器，并在查询大量相关文献的基础上，应用理论分析、数值模拟和试验研究相结合的方法，对该新型集热器的性能进行了比较系统地分析和研究。主要研究内容及结果如下：

1. 针对热管式太阳能集热器的原理及特点，建立水平热管太阳能集热器系统方案，对集热器的核心传热单元—热管具体结构进行了开发。
2. 理论分析了水平状态下热虹吸管的工作原理，包括蒸发段和冷凝段管内工质的流动及传热机理。
3. 根据所设计的结构参数，搭建了热虹吸管传热性能试验台，实验探究了具有不同管径的水平及微倾角放置的光滑铜-水热虹吸管的稳态传热特性。结果表明：随着管径的增加，水平放置热虹吸管的稳态传热性能变佳，且当管外径增大至12mm时，可以实现水平传热，其传热功率达到200W。
4. 在理论分析的基础上，对水平热管真空管太阳能集热器进行了传热性能研究，建立了物理模型，对集热器传热过程进行模拟计算，给出了集热器的集热效率计算方程。
5. 针对南京地区气象参数，选择一种可行的水平热管太阳能集热器方案作为算例进行设计，以110L的水箱为算例，计算出集热器的采光面积，并设计了集热器的外形尺寸，为工程应用提供参照。

上述研究和结论表明将热虹吸管的管外径增大到12mm可实现水平传热，且传输功率可达200W，而太阳能热管所需的传输功率仅为100W左右，所以可以将其应用于集热器中，并且集热器具有更高的传热效率，能更好地与建筑一体化进行配合，具有极高的实用价值。

关键词： 水平热管 太阳能热水器 集热器 集热效率

Development and Research on Solar collector with horizontal heat pipes

ABSTRACT

Solar water heating system is currently the highest efficiency and the largest solar thermal utilization project. Current market is dominated by the solar heat collector with full glass evacuated tubes and the solar heat collector with heat pipes since the heat pipe of solar collector is gravity heat pipe, and is hard to realize the coordination of building integration perfectly. In order to improve the cooperation with building energy conservation, a new solar collector with horizontal heat pipes is proposed in this paper. Performance of the collector is systematically studied with methods of theoretical analysis, numerical simulation and experimental study based on the review of a large number of related references. The main research contents and results are as follows:

1. Basic on the principle and working characteristics of heat pipe solar collector, the scheme of a horizontal heat pipe solar collector system was established. The detailed structure of heat pipe unit which is the core heat transfer unit was developed.
2. The working principles of the thermosiphon placed horizontally are analyzed theoretically, including the flow and heat transfer mechanism of the working fluid in evaporator and condenser.
3. Basic on the structure size of a horizontal heat pipe, the experimental apparatus is built up to test the heat transfer performance of thermosiphon placed horizontally. The steady heat transfer characteristics of the smooth copper-water thermosiphons with different diameters placed horizontally are investigated through experiments. The results show that: with the increasing of diameter, the steady heat transfer performance of the smooth thermosiphon placed horizontally becomes better. When the diameter increases to 12mm, the smooth thermosiphon have good heat transfer performance when placed horizontally, and the heat transfer limitation can reach 200W.
4. Heat transfer performance of the heat pipe solar collector is researched on the basis of theoretical analysis. The thermal efficiency calculation equations of the collector are given by the physical model and the simulation of heat transfer process.
5. According to the meteorological data of Nanjing, select a feasible solar collector with horizontal heat pipes as an example to design.Taking the tank of 110L as an example, the daylight area of the collector is calculated, and the dimension of the collector is designed, provding a reference for engineering application.

The above research work and conclusions suggest that when the diameter of the smooth copper-water thermosiphon increases to 12mm, horizontal thermosiphon placed horizontally can work, and the heat transfer limitation can reach 200W. As the heat transfer limitation of heat pipes used in solar collectors required only about 100W, so it can be used for solar collector more efficaciously and with higher practical values.

Key Words: Horizontal heat pipe；Solar water heater；Collector；Heat collecting efficiency

目 录

摘要................................................................................................................................................I

ABSTRACT................................................................................................................................II

第一章 引言...............................................................................................................................1

1.1 课题的背景………………………...…………………………….................……………1

1.1.1 能源危机………………………………………………………….................………1

1.1.2 太阳能的利用……………………………………………………….................……1

1.2 国内外太阳能集热器的研究进展………………………………....................…………2

1.2.1 国外研究现状…………………………………………….................………………2

1.2.2 国内研究现状……………………………………………….................……………2

1.3 太阳能集热器的分类…………………………………………….................…...………3

1.3.1 平板型太阳能集热器………………………………………….................…………3

1.3.2 真空管型太阳能集热器……………………………………………….................…5

1.4 热管式太阳能集热器........................................................................................................6

1.4.1 太阳能重力热管.........................................................................................................6

1.4.2 热管应用在太阳能集热器中的优越性.....................................................................7

1.4.3 热管太阳能集热器的研究.........................................................................................8

1.4.4 热管太阳能集热器的分类.........................................................................................9

1.5 太阳能热水系统与建筑一体化……………………………………….................…….10

1.5.1 太阳能热水系统存在的问题………………………………………...................…10

1.5.2 太阳能热水系统与建筑集成的思路………………………………...................…10

1.5.3 国内研究与应用现状………………………………………………...................…11

1.6 本课题研究的意义…………………………………………………….................….…11

第二章 水平热管太阳能集热器的开发……………………………….................….…13

2.1 太阳能与建筑的集成机理…………………………………………......................……13

2.2 建筑集成的结构要求…………………………………….....……………….................13

2.3 本章小结………………………….................................................……….................…14

第三章 水平放置热虹吸管的理论分析..........................................................................15

3.1 水平放置的热虹吸管传热过程分析..............................................................................15

3.1.1 冷凝段传热过程分析...............................................................................................15

3.1.2 蒸发段传热过程分析...............................................................................................18

3.2 热虹吸管热极限分析......................................................................................................22

3.2.1 携带极限...................................................................................................................22

3.2.2 干涸极限...................................................................................................................22

3.2.3 沸腾极限...................................................................................................................23

3.3 强化传热机理分析..........................................................................................................23

3.3.1 高效传热工质强化传热机理分析...........................................................................23

3.3.2 管壁内表面处理强化传热机理分析.......................................................................24

3.3.3 管内设置内插件强化传热机理分析.......................................................................24

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