辐射供冷空调方式的特性.doc
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辐射供冷空调方式的特性,摘 要现代社会中，人们关注及享受建筑环境的安全性、健康性和舒适性，而建筑环境质量的保障总是要以能源的巨额消费为代价，空调能耗占到建筑能耗的40％以上。传统空调系统存在诸如浪费能源、污染环境、室内空气品质恶化、舒适度较差等很多弊病，所以，洁净、节能且舒适的辐射空调方式引起了人们的重视。基于这一背景，本文针对辐射供冷系统的...
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摘 要
现代社会中，人们关注及享受建筑环境的安全性、健康性和舒适性，而建筑环境质量的保障总是要以能源的巨额消费为代价，空调能耗占到建筑能耗的40％以上。传统空调系统存在诸如浪费能源、污染环境、室内空气品质恶化、舒适度较差等很多弊病，所以，洁净、节能且舒适的辐射空调方式引起了人们的重视。基于这一背景，本文针对辐射供冷系统的特性和运行过程中出现的结露问题进行了理论研究和实验研究。
本文首先研究了辐射供冷空调系统的传热特性，通过分析换热机理和传热过程，指出了其在传热方式上与传统空调系统不同的特征，得出影响辐射板面温度和辐射供冷系统的供冷能力的各种因素。通过对结露机理和辐射板面上液滴形成过程的研究，得出要使结露现象发生要满足的两个必要条件，影响结露是否会发生、结露程度的因素，总结出防止结露的方法。
在理论研究基础上搭建实验台，对其进行实验研究。本文分析了单独地板辐射、顶板辐射和墙壁辐射三种辐射方式和辐射供冷联合风机盘管系统下实验房间内的热湿环境，包括垂直温度分布、水平温度分布和湿度分布；针对结露现象，通过提供不同的供水流量、供水温度、使用不同的辐射板材料研究结露现象出现的条件和影响因素；对比了单独辐射系统与联合系统供冷下结露现象的不同；利用实验数据计算辐射板不结露、实验室内舒适度较好的状态下的辐射换热量和对流换热量。
最后研究了影响辐射供冷舒适性的要素，并对影响因素进行分析，计算PMV-PPD指标值，评价室内热环境，从该空调系统可以实现热湿独立处理、提高设计温度等方面分析了节能性。
关键词：辐射供冷；换热机理；结露；热舒适性；节能
Abstract
In modern society，people paying close attention to security, healthiness and comfort of built environment and enjoy it. Quality of built environment needs to consume enormous energy. 40 percent of building energy consumption is energy consumption of HVAC. Traditional air conditioning system has many disadvantages, for example, wasting energy, pollution of the environment, deteriorating indoor air quality and so on. Therefore, clean, energy-saving and comfortable radiant cooling system has received great attention. Based on this background, characteristics of radiant cooling system and dew problem have been discussed in this paper.
First, this article studies heat transfer characteristic of radiant cooling system. The difference of heat transfer way between it and traditional air conditioning system is pointed out through analyzing heat transfer of radiant panel. And kinds of factors of affecting radiant panel temperature and the cooling capacity of this system are achieved. This paper also attains two necessary conditions whether dew happens or not and factors of impacting dew phenomenon through analyzing process of drop.
On the foundation of theoretical research, the paper studied experimentally on radiant cooling system. It analyses indoor thermal environment in different air conditioning mode, for example, single radiant floor, single radiant ceiling, single radiant wall and radiant floor combined with fan coil system, including vertical temperature distribution, Level temperature distribution and relative humidity. Research on factors of impacting dew phenomenon by providing different cooling water temperatures and fluxes is completed. Then this paper contrasts difference of dew phenomenon between single radiant cooling system and combined system, besides, works out convection heat flow and radiation heat flow making use of experimental data.
At last, this paper researches on factors impacting thermal comfort, and analyzes them. Afterwards, it estimates thermal comfort through calculating the result of PMV and PPD, then discusses energy conservation of this system because it can realize independent humidity control, raise supplying water temperature and raise design temperature.
Keywords: radiant cooling; heat transfer mechanisms; condensation; thermal comfort; energy-saving
目 录
摘 要 I
Abstract III
第1章 绪 论 1
1.1 课题研究背景 1
1.2 国内外研究历史与现状 2
1.2.1 国内的研究现状与趋势 2
1.2.2 国外的研究现状与趋势 4
1.3 本文的主要研究内容和方法 6
第2章 辐射供冷及其传热特性 7
2.1 辐射供冷的原理 7
2.1.1 热辐射和辐射换热 7
2.1.2 辐射供冷系统的原理 7
2.2 辐射供冷系统的分类 8
2.3 辐射供冷系统的优缺点 9
2.3.1 优点 9
2.3.2 缺点 10
2.4 辐射板传热机理分析 10
2.4.1 盘管内的冷水与管壁之间的换热过程 11
2.4.2 管壁与地板板面的换热过程 12
2.4.3 地板板面与房间的换热过程 14
2.5本章小结 16
第3章 辐射供冷结露问题的理论研究 17
3.1 辐射供冷空调系统中出现的结露现象的危害 17
3.1.1 辐射供冷空调系统中出现的结露现象及危害 17
3.1.2 结露对换热量的影响 18
3.1.3 结露现象出现的可能原因 19
3.2 结露机理 19
3.2.1 均相凝结 20
3.2.2 地板辐射供冷地面上的凝结 21
3.3 影响因素分析 24
3.3.1 辐射板面粗糙度 24
3.3.2 气体与地面的接触角 25
3.3.3 辐射板表面温度 26
3.3.4 空气的温湿度 28
3.4 防止辐射供冷系统结露的措施 30
3.5 本章小结 31
第4章 辐射供冷系..
现代社会中，人们关注及享受建筑环境的安全性、健康性和舒适性，而建筑环境质量的保障总是要以能源的巨额消费为代价，空调能耗占到建筑能耗的40％以上。传统空调系统存在诸如浪费能源、污染环境、室内空气品质恶化、舒适度较差等很多弊病，所以，洁净、节能且舒适的辐射空调方式引起了人们的重视。基于这一背景，本文针对辐射供冷系统的特性和运行过程中出现的结露问题进行了理论研究和实验研究。
本文首先研究了辐射供冷空调系统的传热特性，通过分析换热机理和传热过程，指出了其在传热方式上与传统空调系统不同的特征，得出影响辐射板面温度和辐射供冷系统的供冷能力的各种因素。通过对结露机理和辐射板面上液滴形成过程的研究，得出要使结露现象发生要满足的两个必要条件，影响结露是否会发生、结露程度的因素，总结出防止结露的方法。
在理论研究基础上搭建实验台，对其进行实验研究。本文分析了单独地板辐射、顶板辐射和墙壁辐射三种辐射方式和辐射供冷联合风机盘管系统下实验房间内的热湿环境，包括垂直温度分布、水平温度分布和湿度分布；针对结露现象，通过提供不同的供水流量、供水温度、使用不同的辐射板材料研究结露现象出现的条件和影响因素；对比了单独辐射系统与联合系统供冷下结露现象的不同；利用实验数据计算辐射板不结露、实验室内舒适度较好的状态下的辐射换热量和对流换热量。
最后研究了影响辐射供冷舒适性的要素，并对影响因素进行分析，计算PMV-PPD指标值，评价室内热环境，从该空调系统可以实现热湿独立处理、提高设计温度等方面分析了节能性。
关键词：辐射供冷；换热机理；结露；热舒适性；节能
Abstract
In modern society，people paying close attention to security, healthiness and comfort of built environment and enjoy it. Quality of built environment needs to consume enormous energy. 40 percent of building energy consumption is energy consumption of HVAC. Traditional air conditioning system has many disadvantages, for example, wasting energy, pollution of the environment, deteriorating indoor air quality and so on. Therefore, clean, energy-saving and comfortable radiant cooling system has received great attention. Based on this background, characteristics of radiant cooling system and dew problem have been discussed in this paper.
First, this article studies heat transfer characteristic of radiant cooling system. The difference of heat transfer way between it and traditional air conditioning system is pointed out through analyzing heat transfer of radiant panel. And kinds of factors of affecting radiant panel temperature and the cooling capacity of this system are achieved. This paper also attains two necessary conditions whether dew happens or not and factors of impacting dew phenomenon through analyzing process of drop.
On the foundation of theoretical research, the paper studied experimentally on radiant cooling system. It analyses indoor thermal environment in different air conditioning mode, for example, single radiant floor, single radiant ceiling, single radiant wall and radiant floor combined with fan coil system, including vertical temperature distribution, Level temperature distribution and relative humidity. Research on factors of impacting dew phenomenon by providing different cooling water temperatures and fluxes is completed. Then this paper contrasts difference of dew phenomenon between single radiant cooling system and combined system, besides, works out convection heat flow and radiation heat flow making use of experimental data.
At last, this paper researches on factors impacting thermal comfort, and analyzes them. Afterwards, it estimates thermal comfort through calculating the result of PMV and PPD, then discusses energy conservation of this system because it can realize independent humidity control, raise supplying water temperature and raise design temperature.
Keywords: radiant cooling; heat transfer mechanisms; condensation; thermal comfort; energy-saving
目 录
摘 要 I
Abstract III
第1章 绪 论 1
1.1 课题研究背景 1
1.2 国内外研究历史与现状 2
1.2.1 国内的研究现状与趋势 2
1.2.2 国外的研究现状与趋势 4
1.3 本文的主要研究内容和方法 6
第2章 辐射供冷及其传热特性 7
2.1 辐射供冷的原理 7
2.1.1 热辐射和辐射换热 7
2.1.2 辐射供冷系统的原理 7
2.2 辐射供冷系统的分类 8
2.3 辐射供冷系统的优缺点 9
2.3.1 优点 9
2.3.2 缺点 10
2.4 辐射板传热机理分析 10
2.4.1 盘管内的冷水与管壁之间的换热过程 11
2.4.2 管壁与地板板面的换热过程 12
2.4.3 地板板面与房间的换热过程 14
2.5本章小结 16
第3章 辐射供冷结露问题的理论研究 17
3.1 辐射供冷空调系统中出现的结露现象的危害 17
3.1.1 辐射供冷空调系统中出现的结露现象及危害 17
3.1.2 结露对换热量的影响 18
3.1.3 结露现象出现的可能原因 19
3.2 结露机理 19
3.2.1 均相凝结 20
3.2.2 地板辐射供冷地面上的凝结 21
3.3 影响因素分析 24
3.3.1 辐射板面粗糙度 24
3.3.2 气体与地面的接触角 25
3.3.3 辐射板表面温度 26
3.3.4 空气的温湿度 28
3.4 防止辐射供冷系统结露的措施 30
3.5 本章小结 31
第4章 辐射供冷系..
