太阳能集热和辐射制冷综合利用的理论和实验研究

发布时间：2018-03-08 13:21

本文选题：太阳能集热　切入点：辐射制冷　出处：《中国科学技术大学》2017年博士论文　论文类型：学位论文

【摘要】：目前建筑能耗占我国社会总能耗的1/3左右,而采暖和制冷又是建筑能耗中占比最大的部分。在气候炎热的地区和季节,建筑物的冷能需求较大而热能需求很小,太阳能集热器收集的热能无处消纳;此外,太阳能集热器在夜间也处于闲置状态。辐射制冷技术是指地面物体通过"大气窗口"与低温外太空和高层大气层之间进行辐射换热获得制冷效果的一种被动制冷方式。同样地,辐射制冷装置不适用于气候寒冷的地区和季节,在白天也很难获得冷量,且因单位面积制冷功率偏低而使得投资回收期较长。另一方面,由于平板太阳能集热器和辐射制冷装置在结构上高度相似,功能和工作时段互补,这也为太阳能集热(Photothermic,PT)和辐射制冷(Radiative cooling,RC)在同一套装置上集成提供了可能性。本文提出了太阳能集热和辐射制冷(PT-RC)综合利用的思想,即通过光谱特性和结构参数的设计,将这两种物理过程有机结合在同一套装置上。该复合装置能够实现白天太阳能集热和夜间辐射制冷,从而实现装置的多功能、全天候和跨季节利用,提高能源综合利用效率和时间利用率,缩短投资回收期,促进可再生能源的规模化应用。本文针对太阳能集热和辐射制冷综合利用具体开展了以下研究工作:1、系统性地提出了太阳能集热和辐射制冷综合利用的思想,并给出了复合装置关键部件——板芯和盖板的光谱选择原则。理想的PT-RC板芯在太阳辐射波段(0.2～3μm)和"大气窗口"波段(8～13μm)的吸收/发射率为1,而在其它波段的反射率为1。理想的PT-RC盖板在太阳辐射波段(0.2～3μm)和"大气窗口"波段(8～13μm)的透过率为1,而在其它波段的透过率为0。2、设计和试制了 PT-RC板芯材料,该板芯以阳极氧化铝板为衬底,在其上分别镀有蓝钛选择性吸收涂层和聚酯(PET)薄膜,该PT-RC板芯被称为蓝钛-PET复合表面。光谱测试结果表明,该复合表面具有较明显的光谱选择性,其在太阳辐射波段和"大气窗口"波段的平均吸收/发射率为0.92和0.80,其它波段平均反射率为0.45。3、基于制备的蓝钛-PET复合表面,设计并搭建了一套PT-RC复合系统实验平台,针对该实验平台在不同工作模式和不同运行工况下的集热和制冷性能进行了长期的室外测试。在白天太阳能集热模式时,PT-RC复合系统的瞬态截距集热效率和全天截距集热效率分别为62.7%和38.6%,均达到了传统太阳能集热系统的80%以上;在夜间辐射制冷模式时,复合系统在晴天和阴天的净辐射制冷功率分别为 50.3W/1m2 和 23.4 W/m2。4、建立了一套完整的PT-RC复合系统数学的模型,对复合系统在两种工作模式下的热性能进行模拟计算,并与实验结果进行对比。结果显示,在太阳能集热模式下,系统瞬态集热效率的均方根误差为4.59%;在辐射制冷模式下,系统净辐射制冷功率的均方根误差为4.90%。理论计算结果与实验结果基本吻合,表明该数学模型可准确预测PT-RC复合系统的集热和制冷性能。5、利用验证后的数学模型,研究了不同运行参数对PT-RC复合系统集热和制冷性能的影响;结合典型气象年数据,针对复合系统应用于合肥、北京、福州和乌鲁木齐四个不同气候条件地区的全年性能进行了模拟预测和分析,对复合系统在不同气候条件下的应用提供了优化指导方案。6、在太阳能集热和辐射制冷综合利用的研究基础上,提出了光电-光热-辐射制冷综合利用的概念,以实现在同一套装置上白天光伏发电和太阳能集热,夜间辐射制冷,达到复合装置的多功能性和全天候工作特性。设计并制作了小型PV-PT-RC复合模块,并对其集热和制冷性能进行了初步的实验和理论研究。
[Abstract]:At present, China's building energy consumption accounts for the total energy consumption of about 1/3, while heating and cooling is the largest proportion of building energy consumption. In hot climates and seasons, the building of cold energy greater demand and heat demand is very small, the solar energy heat collector without consumption; in addition, solar collector it is in the idle state at night. Radiation refrigeration technology refers to the ground object through "a passive cooling heat radiation to obtain refrigeration effect between low temperature and atmospheric window of outer space and upper atmosphere. Likewise, radiation cooling device is not suitable for cold climates and seasons in the daytime, it is difficult to get cold, and because the unit area of low refrigeration power and makes a longer payback period. On the other hand, the flat plate solar collector and radiation cooling device in the structure of high similarity function and working time each other This is also set up, solar thermal (Photothermic, PT) and radiation refrigeration (Radiative cooling, RC) in the same device integration provides the possibility. This paper proposes a solar heat and radiation refrigeration (PT-RC) comprehensive utilization of ideas, namely the design through the spectral characteristics and structure parameters, the two the physical process of the organic combination of the same equipment. The composite device can realize the daytime thermal solar radiation cooling at night, so as to realize the multifunctional device, all-weather and seasonal utilization, improve energy utilization efficiency and time efficiency, shorten the recovery period of investment, to promote large-scale application of renewable energy. The solar energy in the comprehensive utilization of heat and radiation refrigeration to carry out specific research work as following: 1. Systematically put forward the comprehensive utilization of solar heat and radiation refrigeration theory, and gives the composite device key components- Optical plate core and the cover plate. The selection principle of PT-RC plate core ideal in solar radiation band (0.2 ~ 3 m) and the atmospheric window band (8~13 m) of the absorption / emission rate was 1, and the other is PT-RC band reflectance in cover plate 1. ideal in the solar radiation band (0.2 ~ 3 m) and the atmospheric window band (8~13 m) by the rate of 1, while in the other band through rate of 0.2, design and manufacture of PT-RC plate core material, the core plate with anodized aluminum plate as a substrate, on which are respectively coated with titanium blue selective absorption coating and polyester (PET) film, the PT-RC core plate is called a blue titanium -PET composite surface. The spectrum results show that the composite surface has obvious spectral selectivity, the solar radiation band and the atmospheric window band average absorption / emission rate of 0.92 and 0.80, the other band average reflectance is 0.45.3 prepared blue titanium complex based on -PET The surface, designed and built a PT-RC test platform for complex system, and set the refrigeration performance of the experimental platform in different working modes and operating conditions of the outdoor test long term. In the daytime solar heat collecting mode, transient intercept PT-RC composite system in thermal efficiency and collector efficiency were all day long. 62.7% and 38.6% were achieved more than traditional solar collector system 80%; radiation cooling mode at night, the composite system of net radiation in sunny and cloudy refrigeration power were 50.3W/1m2 and 23.4 W/m2.4, the establishment of a complete set of PT-RC composite system mathematical model is used to simulate the thermal performance of the composite system in two working mode, and compared with the experimental results. The results showed that in the solar heat mode, transient heat collecting efficiency of the root mean square error is 4.59%; in radiation refrigeration Model, the root mean square error of system net radiation cooling power is 4.90%. the theoretical calculation results agree well with the experimental results, show that the mathematical model can accurately predict the performance of.5 PT-RC composite heat collection and refrigeration system, then the model, studies the different operation parameters influence the composite system of PT-RC and the number of sets of refrigeration performance; combined with the typical meteorological year data, the composite system applied in Hefei, Beijing, the annual performance of four different climate regions in Fuzhou and Urumqi were predicted and analyzed, providing guidance on Application of composite optimization scheme of.6 system under different climatic conditions, based on the comprehensive utilization of solar heat and radiation cooling. Put forward the concept of comprehensive utilization of photoelectric - thermal radiation cooling, in order to achieve the same device during the photovoltaic and solar thermal, night radiative cooling To achieve the versatile and all-weather operational characteristics of the composite device, a small PV-PT-RC composite module is designed and made, and its thermal and refrigeration performance is preliminarily studied theoretically and experimentally.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TK51

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