碳系微纳结构材料局部吸光沸腾集热特性研究

发布时间：2018-03-01 10:37

  本文关键词： 碳系材料 局部吸光 集热特性　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：如何高效捕集太阳光,产生蒸汽,是太阳能光热应用领域的一个关键问题。本文利用碳系微纳结构材料局部吸光沸腾的方法,选用石墨烯、膨胀石墨ER300、膨胀石墨ER50等材料,在光照下加热水产生蒸汽,探究光功率密度、碳材料层厚度、光源对光热转换过程集热特性的影响。实验表明,添加碳材料有利于提高光照过程蒸汽的产量,在使用红光灯、光功率密度为2.5 W/cm2、碳材料层厚度为1 mm的条件下,添加石墨烯组蒸汽产量最大,较纯水组提高了 16.3%。添加石墨烯可缩短升温过程所需的时间,添加膨胀石墨ER300可提高蒸汽温度。碳材料层厚度加大会使蒸汽产量下降,蒸汽温度提高,在使用红光灯、光功率密度为2.5 W/cm2的条件下,石墨烯层厚度由1mm增至3mm时,蒸汽产量减少17.3%,蒸汽温度提高11.5%,同时升温过程明显缩短。在两种光源的对比实验中,使用氙灯进行实验时,蒸汽温度最高为59.4℃。使用红光灯可提高光照过程蒸汽产量,在光功率密度为1 W/cm2、碳材料层厚度为1mm的条件下,使用红光灯组产生的蒸汽量分别比使用氙灯组、纯水组提高了 136.9%和376.0%。本文通过理论计算得知,碳系微纳结构材料吸光沸腾过程中,微纳尺寸颗粒间隙作为沸腾核心,在较高光功率密度光照下可产生过热蒸汽。通过建立传热分析模型,计算得出碳材料层表面向环境辐射、与空气对流是实验系统主要散热途径,二者总散热量合占系统输入总能量的19.7%。
[Abstract]:How to capture solar light efficiently and produce steam is a key problem in solar photothermal application field. In this paper, graphene, expanded graphite ER300, expanded graphite ER50 and other materials are selected by means of local absorption boiling method of carbon system micro and nano structure materials, such as graphene, expanded graphite ER300, expanded graphite ER50 and so on. The effects of light power density, thickness of carbon material layer and light source on the heat collecting characteristics of photothermal conversion process are investigated. The experiment shows that adding carbon material is beneficial to increase the steam output in the process of illumination, and the red light lamp is used. When the optical power density is 2.5 W / cm ~ 2 and the thickness of the carbon layer is 1 mm, the steam output of the graphene group is the largest, which is 16. 3% higher than that of the pure water group. The addition of expanded graphite ER300 can increase the steam temperature, the thickness of the carbon layer will decrease the steam production, and the steam temperature will increase. When the red light lamp is used, the thickness of the graphene layer increases from 1 mm to 3 mm when the optical power density is 2.5 W / cm 2. The steam production was reduced by 17.3%, the steam temperature was increased by 11.5%, and the heating process was obviously shortened. In the contrast experiment between the two light sources, the maximum steam temperature was 59.4 鈩，

本文编号：1551557