耐高温真空绝热复合板制备与热性能研究毕业论文
2022-01-09 21:56:51
论文总字数:21750字
摘 要
真空绝热板(Vacuum Insulation Panel,VIP)是基于真空隔热机理设计的新一代高性能保温材料,拥有着目前所有绝热材料中最低的导热系数。目前使用的VIP膜材主要是铝塑膜,90℃以上会发生软化,不能耐高温。本课题以304不锈钢箔为膜材,以湿法制备的玻璃纤维为芯材,通过激光焊接和真空熔覆工艺制备耐高温真空绝热复合板,测试了复合板热性能,并分析了膜材结构和工艺对VIP热性能的影响规律。结果如下:
(1)以超细玻璃纤维为芯材,以0.2mm厚度304不锈钢箔为封装外壳,通过高真空焊接封装工艺制备耐高温真空绝热复合板材,其常温(24℃)导热系数仅为0.0016W/(m•K),高温(400℃)导热系数为0.0032W/(m•K),并且吸水率仅为0.1%。
(2)气流打浆在保持纤维完整性上具有明显优势,同时能耗更低,效率更高,根据超细玻璃棉芯材的要求,选择合理的打浆时间,能够获取更高品质的纤维浆料。
(3)过高和过低的浆料浓度都会造成纤维长度剧烈下降,尤其是高浆料浓度条件下,纤维长度衰减趋势更为明显。使用1.5‰的浆料浓度参数,更容易获得高品质的芯材。
(4)纤维直径是影响真空绝热材料的关键因素,并且真空绝热材料导热系数随内压变化的敏感性主要取决于纤维直径。
关键词:真空绝热板;玻璃纤维芯材;导热系数;304不锈钢箔;激光焊接
Preparation and thermal properties of high-temperature-resistant vacuum insulated composite panel
ABSTRACT
Vacuum insulation panel (VIP) is a new generation of high-performance thermal insulation material designed based on thermal insulation structure and vacuum thermal insulation mechanism. It has the lowest thermal conductivity of all thermal insulation materials. The currently used VIP film materials are mainly aluminum-plastic films, which will soften above 90 ° C and cannot withstand high temperatures. In this project, 304 stainless steel foil was used as the film material, and the glass fiber prepared by the wet method was used as the core material. Through laser welding and vacuum cladding technology, high temperature resistant vacuum insulation composite plate is prepared. The thermal performance of composite plate is tested, and the influence of membrane structure and technology on VIP thermal performance is analyzed. The results are as follows:
(1) The heat-resistant vacuum insulation composite plate was prepared by high vacuum welding with ultra-fine glass fiber as the core material and 304 stainless steel foil of 0.2m m thickness as the packaging shell. Its heat conductivity at room temperature (24 ℃) is only 0.0016w / (m · K), at high temperature (400 ℃) is 0.0032w / (m · K), and its water absorption is only 0.1%.
(2) Air beating has obvious advantages in maintaining fiber integrity, lower energy consumption and higher efficiency. According to the requirements of ultra-fine glass wool core material, choosing a reasonable beating time can obtain higher quality fiber size.
(3) Too high and too low pulp concentration will lead to a sharp decline in fiber length, especially in the condition of high pulp concentration, the decline trend of fiber length is more obvious. Using 1.5 ‰ slurry concentration parameter, it is easier to obtain high quality core material.
(4) The fiber diameter is the key factor affecting the vacuum insulation material, and the sensitivity of the thermal conductivity of the vacuum insulation material to the internal pressure mainly depends on the fiber diameter.
Keywords: vacuum insulation panel; glass fiber core material; thermal conductivity; 304 stainless steel foil; laser welding
目录
摘要 I
ABSTRACT II
第一章 绪论 1
1.1背景与意义 1
1.2真空绝热板发展现状 2
1.3本文主要研究目的及内容 5
第二章 材料制备及性能表征 7
2.1材料制备 7
2.1.1实验原料 7
2.1.2 制备流程 8
2.2表征测试 10
2.2.1 扫描电镜观察 10
2.2.2 芯材孔径分布和平均孔径 11
2.2.3 导热系数测试 11
2.2.4 真空绝热板高温高湿耐老化性能测试 12
第三章 试验结果及分析 13
3.1玻璃纤维芯材成型影响规律 13
3.1.1打浆方式和打浆时间对纤维长度的影响 13
3.1.2浆料浓度对芯材纤维长度影响 14
3.2外包覆膜材激光焊接工艺研究 16
3.2.1激光功率对焊缝表面形貌和组织结构的影响 16
3.2.2 激光功率对力学性能的影响 19
3.2.3 焊接速度对焊缝表面形貌和组织结构的影响 19
3.2.4焊接速度对力学性能的影响 21
3.3耐高温真空绝热复合材料板材制备 22
3.4 制备VIP样品及其导热特性 24
3.5经济性分析 24
第四章 结论与展望 26
4.1结论 26
4.2展望 27
参考文献 28
致 谢 30
第一章 绪论
1.1背景与意义
过去几十年中,工业化快速普及,能源的消耗水平快速提高,能源危机开始成为人们关注的重点问题。而工业、交通和建筑产生的能耗则是全球能源消耗的主要方面,其中,光是建筑能耗就占了全球总能源消耗量的40%[1]。能源的过度消耗,毫无疑问会透支未来社会发展的动力,同时也会对环境产生负面的影响。化石能源在燃烧时会释放大量有害气体,以及因为不完全燃烧产生的固体小颗粒,污染环境。要想缓解环境问题只有两种途径:开源以及节流。开源,人们已经开始大力地研究发展太阳能、风能等等,但是这些能源都有一定的不可控性以及区域性差异,这就要求能源的跨区域调配;节流,就必须要减少能源消耗,从根源抓起,提高能源利用效率尤为重要。有些国家将节能视作继煤炭、石油、天然气、核能四大能源之后的“第五大能源”[2]。另一方面,它也是能源的跨区域高效调配的关键因素。节能包括两种方式:一是节能软技术,就是提高群众的环保节能意识,建立小到城镇大到国家级别的能源管理调节制度,出台相应的节约能源的政策,例如建立联合供电系统以此来提高能源的利用效率;二是节能硬技术,通过硬件的优化改造、已有的科学技术改良机械设备的能源损耗率。
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