论文总字数：28190字

摘 要

一方面随着人口的不断增长，淡水资源日益稀缺；另一方面随着工业的迅速发展，废水排放量加剧。空气循环蒸发技术作为一种新型的蒸发技术，可以有效实现淡水的生产和工业废水的处理。本文以能量守恒原理和质量守恒原理作为理论依据，基于夹点分析理论建立空气循环蒸发系统的热力学模型。通过Matlab软件求解空气循环蒸发系统的热力学模型，以不同循环结构的系统为研究对象，研究不同系统循环结构下质量流量比、夹点温差、加湿器液体进口温度对系统性能的影响。以空气开式水闭式系统为例，具体分析了不同系统输入参数对蒸发比、造水比、回热比的影响，同时从蒸发比、造水比、回热比三个方面比较三种不同循环结构系统的性能，从而确定最优系统循环结构，本文的主要结论如下：

1. 对于空气开式水闭式系统、空气开式水开式系统和空气闭式水开式系统，随着加湿器液体进口温度的升高，最优的质量流量比会增大，造水比、蒸发比、回热比的最大值会减小。
2. 当夹点温差不同时，空气开式水闭式系统最优质量流量比会发生改变，最优质量流量比的值随着夹点温差的增大而减小。而在空气开式水开式系统和空气开式水闭式系统中，最优质量流量比的值不随夹点温差的改变而发生变化。
3. 当空气开式水闭式系统、空气开式水开式系统、空气闭式水开式系统回热比达到最大值时，蒸发比和造水也达到最大值，此时系统的能量利用效率最高，综合性能最好。
4. 从造水比角度来说，空气开式水闭式系统具有最大的造水比。当质量流量比小于2时，空气闭式水开式是最佳系统循环结构；当质量流量比在2到3之间时，空气闭式水开式或者空气开式水开式是系统最佳循环结构；当质量流量比大于6时，空气开式水闭式是最佳系统循环结构。
5. 从蒸发比角度来说，空气开式水闭式系统具有最大的蒸发比。当质量流量比小于3时，空气开式水闭式系统或者空气开式水开式是最佳系统循环结构；当质量流量比大于4时，空气开式水闭式系统是最佳系统循环结构。

关键词：加湿除湿 蒸发脱盐 热力学分析 造水比 蒸发比

ABSTRACT

On the one hand, as the population continues to grow, freshwater resources are increasingly scarce; on the other hand, with the rapid development of industry, wastewater discharge has increased. As a new type of evaporation technology, air circulation evaporation technology can effectively realize the production of fresh water and the treatment of industrial wastewater. In this paper, based on the energy and mass conservation, the thermodynamic model of the air humidification-dehumidification evaporation system is developed by applying pinch analysis. The thermodynamic model of the air humidification-dehumidification evaporation system is solved by Matlab software, and the system with different cycle configuration is the research object. The effects of the mass flow ratio, pinch point temperature difference, and the liquid inlet temperature in the humidifier on the system performance with different cycle configurations were studied. The closed-water open-air cycle system was taken as an example to specifically analyze the different system input parameters on evaporation input ratio, gained output ration, and heat recovery ratio. At the same time, the optimal system cycle configuration is determined by comparing the performance of three systems with different cycle configuration from evaporation input ratio, gained output ratio and heat recovery ratio. The main conclusions of this dissertation are as follows:

1. For closed-water open-air cycle system, open-water open-air cycle system and closed-air open-water cycle system, as the liquid inlet temperature in the humidifier increases, the optimal mass flow ratio will increase. The maximum value of evaporation input ratio, gained output ratio and heat recovery ratio will decrease.
2. When the pinch point temperature difference is different, the value of the optimal mass flow rate of the closed-water open-air cycle system will change, and the value of the optimal mass flow rate decreases as the pinch point temperature difference increases. In the open-water open-air cycle system and the closed-air open-water cycle system, the value of the optimal mass flow ratio does not change with the change of the pinch point temperature difference.
3. When the heat recovery ratio of closed-water open-air cycle system, open-water open-air cycle system and closed-air open-water cycle system reaches the maximum value, the evaporation input ratio and gained output ratio also reach the maximum value. At this time, the energy utilization efficiency of the system is the highest and the comprehensive performance is the best.
4. In terms of gained output ratio, closed-water open-air cycle system has the maximum gained output ratio. When the mass flow ratio is less than 2, closed-air open-water is the optimal system cycle configuration. When the mass flow ratio is between 2 and 3, closed-air open-water or open-water open-air is the optimal system cycle configuration. When the mass flow ratio is greater than 6, closed-water open-air is the optimal system cycle configuration.
5. In terms of evaporation input ratio, closed-water open-air cycle system has the maximum evaporation input ratio. When the mass flow ratio is less than 3, closed-water open-air or open-water open-air is the optimal system cycle configuration; when the mass flow ratio is greater than 4, closed-water open-air is the optimal system cycle configuration.

Key Words: Humidification-dehumidification; Evaporation; Thermodynamic analysis; Gained output ratio; Evaporation input ratio

目 录

摘 要 I

ABSTRACT II

符号表 VI

第一章 绪论 1

1.1 研究背景 1

1.2 空气循环蒸发技术 1

1.2.1 空气循环蒸发技术的原理及分类 2

1.2.2 空气循环蒸发技术国内外研究进展 2

1.3 本文研究内容及意义 4

1.3.1 研究内容 5

1.3.2 课题意义 5

第二章 空气循环蒸发系统模型 6

2.1 系统描述 6

2.1.1空气开式水闭式（CWOA）系统 6

2.1.2空气开式水开式（OWOA）系统 6

2.1.3空气闭式水开式（CAOW）系统 7

2.2模型假设 7

2.3 模型建立 8

2.3.1 加湿器 8

2.3.2 除湿器 10

2.3.3 加热器 10

2.4性能参数 11

2.5求解思路 12

2.6本章小结 12

第三章 空气循环蒸发系统性能分析 13

3.1 空气开式水闭式系统造水比的分析 13

3.2 空气开式水闭式系统蒸发比的分析 14

3.3 空气开式水闭式系统回热比的分析 16

3.4 本章小结 18

第四章 不同系统循环结构的比较与优化 19

4.1 造水比的比较 19

4.2 蒸发比的比较 21

4.3 回热比的比较 23

4.4 本章小结 25

第五章 结论及展望 27

5.1 本文主要结论 27

5.2 工作展望 27

参考文献 29

致 谢 33

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