CO2热泵热水器中翅片管式蒸发器的研究

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摘要

随着人们生活水平的日益提高，人们的环保意识越来越强，并且对舒适性的

要求也越来越高。由于 CFCs 类制冷工质会对臭氧层的破坏和产生的温室效应等环

境问题，人们重新重视自然工质的利用。CO2作为自然工质之一，具有良好的热物

性，比传统工质有很大的优势，CO2在很多方面都有很好的应用前景，尤其在热泵

方面的应用。采用 CO2作为制冷剂的热泵热水器在日本已经广泛使用，但在国内

还没有成熟的产品，对 CO2作为制冷剂的研究仍处在理论和实验阶段。

本课题主要是针对小型 CO2热泵热水器进行研究，通过理论与实验相结合的

方法对翅片管式蒸发器进行研究，为热泵热水器的实际的应用提供理论依据和实

验数据，具有一定的实用价值。

本课题主要研究内容是：研究外部环境和内部运行参数对蒸发器性能和系统

性能的影响，在不同工况（名义工况、夏季工况、冬季工况）下进行实验研究，

分析外部环境和内部运行参数对二氧化碳热泵热水器的性能的影响；并在名义工

况条件下，改变进水流量、进水温度，分析对系统内部性能的影响和对蒸发器整

体性能的影响；并研究冬季工况下制热条件下，结霜对系统性能的影响；通过专

用的模拟软件 EVAP-COND V3.0 软件对翅片管蒸发器进行模拟分析。

理论分析得出：制冷剂侧表面传热系数随着制冷剂的质量流率和热流密度的

增加而逐渐增大。实验数据分析得出：随着蒸发温度逐渐增加，蒸发器侧换热量

逐渐增加；系统的性能系数也随之增加。但在不同的进水流量下，随着进水流量

的增加，蒸发器侧换热量逐渐增加，系统的性能系数也随之升高；随着进水温度

的增加，蒸发器侧的换热量逐渐减小，系统的性能系数随着进水温度的增加也逐

渐降低。

本课题研究的实验结论是：CO2热泵热水器系统在三种工况条件下，可以制取

较高温度（65℃以上）的热水，符合国标《家用和类似用途热水器》的标准。在

三种运行工况下，夏季工况的系统性能系数 COP 最高，约为 4.5 以上；名义工况

次之，系统的性能系数 COP 为3.8 以上，冬季工况最低，系统的性能系数 COP 为

3.2。

关键词：CO2跨临界循环热泵热水器翅片管式蒸发器结霜

ABSTRACT

With the improvement people's living standards, people pay much attention to the

environmental protection, and demand the comfort of our living. It brings a new

importance to use the natural refrigerants becase the traditional refrigerants CFCs

caused ozone depletion and house effect and other environmental problems. CO2 is as

one of the natural refrigerants, used in refrigerating equipments with the nature of the

good of thermophysical properties and transcritical cycle. CO2 trans-critical has used in

many good prospect of application, especially in the heat pump applications; there are

great advantages than the traditional working fluid. The use of CO2 heat pump water

heaters have been a lot used in Japan, but in our country it CO2 as a refrigerant is not yet

a mature product, still in the theoretical and experimental stages.

The main subject of small CO2 heat pump water heater is a experimental study;

The points of the research have focused on CO2 heat pump water heater heat exchanger,

carried out reseach on finned-tube evaporator by theoretical and experimental method,

to provide a theoretical basis and practical value for future commercial aircraft.

The main subject of researches: study of the external environment and internal

operating environment parameter changes affect the performance of the evaporator and

system performance, different experimental conditions (nominal conditions, summer

conditions, winter conditions), the analysis of externalenvironment and internal

operating environment of carbon dioxide heat pump water heater performance; And

under the nominal working conditions, we analyze the impact on system performance

and effects on the overall performance of the evaporator with changing in water flow,

water temperature; frost impact on system performance and study the heating

conditions; EVAP-COND V3.0 software on a dedicated simulation software to

simulate the finned tube evaporator analysis.

Theoretical analysis: side surface coefficient of heat transfer of refrigerant

gradually increases as the refrigerant mass flow rate and the heat flow density increase.

Experimental data analysis: the evaporator side heat transfer increases gradually with

the evaporation temperature increasing; the performance of the system coefficient also

increases. But under different water flow, with the increase of feed flow rate, the

evaporator side heat transfer increases gradually, the performance of the system

coefficient also increases; with the increase of feed temperature and evaporator side

III

heat transfer gradually decreases, and the performance of the system coefficient with

the increase of inlet temperature is gradually reduced.

Experimental conclusions of the research showed that CO2 heat pump water

heater system can run normal under all the different seasons’work conditions, and the

high temperature hot water system can be produced more than 65 ℃. Hot water will

meet the requirements. In running summer conditions, the coefficient of performance

COP is the highest, values above 4.5; followed by the nominal conditions, COP is 3.8;

the lowest is in winter conditions, which values is able to more than 3.2.

Key Words：CO2 trans-critical cycle，heat pump water heater，finned

tube evaporator，frosting

摘要

ABSTRACT

第一章绪论 ............................................................................................................... 1

1.1 课题研究背景与意义 ........................................................................................ 1

1.1.1 二氧化碳制冷剂的发展 .............................................................................. 1

1.1.2 制冷工质的替代方向 .................................................................................. 2

1.1.3 二氧化碳制冷剂的应用领域 ...................................................................... 3

1.2 国内外研究现状 ................................................................................................ 4

1.2.1 空气源热泵热水器的发展 .......................................................................... 4

1.2.2 二氧化碳热泵热水器的发展 ...................................................................... 5

1.2.3 二氧化碳热泵热水器各部件的研究 .......................................................... 7

1.2.4 二氧化碳系统仿真模拟进展 .................................................................... 12

1.3 本课题研究内容 .............................................................................................. 14

第二章二氧化碳的换热特性和循环性能的理论研究 ........................................... 16

2.1 二氧化碳的物理性质 ...................................................................................... 16

2.2 二氧化碳的流动与换热特性 .......................................................................... 17

2.2.1 普通管内亚临界强迫对流沸腾换热特性 ................................................ 17

2.2.2 微通道管内亚临界强迫对流沸腾换热特性 ............................................ 18

2.2.3 亚临界强迫对流沸腾换热系数实验关联式 ............................................ 19

2.2.4 强迫对流沸腾流动压降关联式 ................................................................ 22

2.3 热泵循环效性能的影响因素分析 .................................................................. 22

2.3.1 热泵循环的性能系数 COP ....................................................................... 22

2.3.2 最优高压侧压力的计算 ............................................................................ 24

2.4 本章结论 .......................................................................................................... 25

第三章蒸发器的实验研究 ....................................................................................... 26

3.1 蒸发器结构 ...................................................................................................... 26

3.2 试验台介绍 ...................................................................................................... 27

3.2.1 试验台原理图 ............................................................................................ 28

3.2.2 试验台主要部件介绍 ................................................................................ 29

3.3 实验台辅助设备 .............................................................................................. 31

3.3.1 外部环境 .................................................................................................... 31

3.3.2 温度和压力的测量 .................................................................................... 32

3.3.3 流量测定 .................................................................................................... 33

3.3.4 数据采集系统 ............................................................................................ 33

3.4 实验数据理论分析 .......................................................................................... 34

3.4.1 制冷剂侧沸腾换热系数 ............................................................................ 34

3.4.2 空气侧的换热 ............................................................................................ 37

3.5 结果分析 .......................................................................................................... 41

3.5.1 对制冷剂侧换热系数、管内压降的影响 ................................................ 41

3.5.2 对蒸发器侧换热量的影响 ........................................................................ 43

3.5.3 对系统性能系数的影响 ............................................................................ 44

3.6 本章结论 .......................................................................................................... 45

第四章结霜工况下蒸发器的研究 ........................................................................... 47

4.1 理论分析 .......................................................................................................... 47

4.1.1 霜的形成机理 ............................................................................................ 47

4.1.2 结霜对系统参数的影响 ............................................................................ 47

4.2 实验分析 .......................................................................................................... 50

4.2.1 外部环境影响因素 .................................................................................... 50

4.2.2 蒸发器性能的影响 .................................................................................... 52

4.3 除霜技术的应用和改进 .................................................................................. 55

4.4 本章结论 .......................................................................................................... 55

第五章二氧化碳翅片式蒸发器的模拟和优化 ....................................................... 57

5.1 EVAP-COND V3.0 软件说明 ........................................................................ 57

5.1.1 性能的模拟计算功能 ................................................................................ 57

5.1.2 模型的优化设计功能 ................................................................................ 57

5.2 模型的建立 ...................................................................................................... 58

5.2.1 翅片管换热器模拟的建立 ........................................................................ 58

5.2.2 制冷剂流程模型的建立 ............................................................................ 59

5.2.3 模拟计算分析 ............................................................................................ 59

5.2.4 模型优化设计 ............................................................................................ 60

5.3 模拟分析 .......................................................................................................... 61

5.3.1 外部环境对蒸发器性能的影响 ................................................................ 61

5.3.2 制冷剂进口干度对蒸发器性能的影响 .................................................... 61

5.3.3 制冷剂出口过热度对蒸发器性能的影响 ................................................ 62

5.4 本章小结 .......................................................................................................... 63

第六章结论及展望 ................................................................................................... 64

6.1 结论 .................................................................................................................. 64

6.2 后续工作展望 .................................................................................................. 65

参考文献 ........................................................................................................................ 66

在读期间公开发表的论文和承担科研项目及取得成果 ............................................ 72

致谢 ................................................................................................................................ 73

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摘要：

I摘要随着人们生活水平的日益提高，人们的环保意识越来越强，并且对舒适性的要求也越来越高。由于CFCs类制冷工质会对臭氧层的破坏和产生的温室效应等环境问题，人们重新重视自然工质的利用。CO2作为自然工质之一，具有良好的热物性，比传统工质有很大的优势，CO2在很多方面都有很好的应用前景，尤其在热泵方面的应用。采用CO2作为制冷剂的热泵热水器在日本已经广泛使用，但在国内还没有成熟的产品，对CO2作为制冷剂的研究仍处在理论和实验阶段。本课题主要是针对小型CO2热泵热水器进行研究，通过理论与实验相结合的方法对翅片管式蒸发器进行研究，为热泵热水器的实际的应用提供理论依据和实验数据，具有一定的实用价值。本课...

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