可调高功率脉冲磁控溅射法制备太阳能选择性吸收光热涂层

发布时间：2018-04-24 02:27

  本文选题：太阳能选择吸收光热涂层 + MPPMS　； 参考：《山东大学》2017年硕士论文

【摘要】：为了缓解能源供给紧张的问题,人们在竭尽所能地合理高效利用现有能源的同时不断开发新能源。太阳能是一种含量丰富且无污染的天然能源,是国际公认的竞争力巨大的未来能源之一。目前科研工作者已开发出多种太阳能利用的方式,其中太阳能光热转换技术是最简单、直接的能量转换方法,该技术发展较早且应用广泛。如今,太阳能热水器已普遍参与到大多数家庭的日常生活中,是商业化水平最高的太阳能热利用技术。太阳能的能量密度较低,即品质不高,因此必须利用太阳能集热器等技术来提高光热转换率,从而实现太阳能的充分有效利用,而太阳能选择性吸收光热涂层是太阳能集热器的主要组成,为了提高光热转换效率,光热涂层应在太阳光范围内尽可能增加吸收,而在红外波长范围内尽可能降低自身热辐射。同时光热涂层的耐候性也是太阳能利用中不容忽视的问题,它决定了太阳能热水器的耐久性和稳定性。因此,我们需要对已有的工艺进行不断地优化,开发更优的工艺技术,制备出具有优异的光学性能及耐候性能的太阳能选择性吸收光热涂层。基于以上背景,利用可调脉冲高功率反应磁控溅射技术(MPPMS)在铁素体不锈钢(SS)基体上沉积Cu/TiN/TiSiN/SiN太阳能选择性吸收光热涂层(SSACs)。在此系统中,Cu、TiN、TiSiN和SiN分别用作红外反射层、主吸收层、次吸收层和减反层。在优化工艺参数条件下制备的SS/Cu/TiN/TiSiN/SiN光热涂层,其平均吸收率为0.944和平均发射率为0.057,α/ε值为16.02。另一方面,采用同一工艺参数制备了不含Cu层的光热涂层,即SS/TiN/TiSiN/SiN,该涂层显示出与含Cu涂层相似的吸收率(～0.95),但是发射率较高,整体的选择性吸收性能不好。同时,X射线衍射分析表明,Cu层是多晶结构,而TiN、TiSiN和SiN各层均是非晶结构。为验证光热涂层的耐温性能,将太阳能选择性吸收光热涂层样品分别进行了真空和空气环境的耐温测试。在真空环境中分别加热到500℃、600℃和700℃,保温2小时,其中在500℃条件下,其光热吸收性能无明显变化;而在空气环境中,分别在200℃、250℃、300℃和350℃下保温2小时,其中温度高达250℃时,涂层仍能保持较好的选择性吸收性能,300℃时其光热性能开始下降。采用原子力显微镜(AFM)图像和XRD光谱来研究不同水平耐温测试下涂层的表面形貌和显微结构的变化,更进一步证明了 SS/Cu/TiN/TiSiN/SiN光热涂层具有优异的耐温性能。
[Abstract]:In order to alleviate the shortage of energy supply, people try their best to make rational and efficient use of existing energy and develop new energy. Solar energy is a kind of rich and pollution-free natural energy, which is one of the internationally recognized competitive energy sources in the future. At present, researchers have developed a variety of solar energy utilization methods, among which the solar photothermal conversion technology is the simplest and direct energy conversion method, the technology has been developed earlier and widely used. Nowadays, solar water heaters are widely used in most families and are the most commercialized solar thermal technologies. The energy density of solar energy is low, that is, the quality is not high, so it is necessary to use solar collector and other technologies to improve the conversion rate of light and heat, so as to realize the full and effective utilization of solar energy. The solar selective absorption photothermal coating is the main component of solar collector. In order to improve the photothermal conversion efficiency, the photothermal coating should increase the absorption in the range of solar light as much as possible, and reduce its own thermal radiation as much as possible in the range of infrared wavelength. At the same time, the weathering resistance of photothermal coating is also a problem that can not be ignored in solar energy utilization, which determines the durability and stability of solar water heater. Therefore, we need to optimize the existing processes and develop better technology to prepare solar selective absorption photothermal coatings with excellent optical properties and weathering resistance. Based on the above background, Cu/TiN/TiSiN/SiN solar selective photothermal absorption coating was deposited on ferrite stainless steel (SS) substrate by adjustable pulse high power reactive magnetron sputtering (MPPMS) technique. In this system, TiSiN and SiN are used as infrared reflectance layer, main absorption layer, secondary absorption layer and antireflection layer, respectively. The average absorptivity, average emissivity and 伪 / 蔚 value of SS/Cu/TiN/TiSiN/SiN photothermal coating were 0.944, 0.057 and 16.02, respectively. On the other hand, the photothermal coating without Cu layer was prepared by using the same process parameters. The coating shows a similar absorptivity to that of Cu containing coating, but its emissivity is high and the overall selective absorption property is not good. At the same time, X-ray diffraction analysis shows that the Cu layer is polycrystalline, while the TiSiN and SiN layers are amorphous. In order to verify the thermal resistance of photothermal coatings, the samples of solar selective absorption photothermal coatings were tested in vacuum and air environment respectively. They were heated to 500 鈩，

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