Relevant Applications
VIPs can be used in many important fields.
Vacuum Insulation Panels (VIPs) are ultra-thin, high-performing insulants that can be up to 20 times more effective than traditional insulation products.VIPs provide energy efficiency and space benefits for:
- Buildings;
- Home Appliances;
- Refrigerated Transportation Systems, including COVID-19 vaccines; and
- Any other Applications requiring Low Energy Loss from heat transfer.
第一个真空绝热板是1930年用橡胶套包裹的多孔材料制成的。20世纪60年代开始出现纳米材料。而在50年代，我们将玻璃棉芯装入焊封的钢板中。随着VIP的快速发展，到90年代，第一个通过沉淀氧化硅制成的真空绝热板面世了。
在100多年前，我们已经发现了真空绝热的原理，将此原理用于设计设备也已经出现了几十年。现在随着材料科学的进步，以及对于建筑物的能源效率的日益关注，真空绝热板产品被广泛应用于许多以前不曾对其使用的领域。
优点
A Vacuum Insulation Panel consists of a rigid, highly-porous core material encased in a thin, gas-tight outer envelope. The envelope is evacuated and sealed to prevent outside gases from entering the panel. The combination of porous material and the vacuum results in an extremely high thermal resistance. The thermal resistance allows for thinner insulation in applications where space is at a premium.
Core materials for VIPs
Core Materials for VIPs require a completely open-porous structure to allow evacuation. These materials must have a sufficiently high compressive strength to withstand the mechanical pressure load. Core material classes basically comprise three structures as microporous powders, fibres and foams.
Each structure has its inherent solid mechanical properties. The minimum density to withstand atmospheric pressure loads is distinctive. The same is valid for the centre of panel (COP) value for the thermal conductivity, which depends on the solid backbone of the core material. The core material should have the lowest possible thermal conductivity to ensure the VIP’s best performance.
Optimum materials have a microporous structure and are able to absorb humidity. Otherwise, getters have to be added. The most common core materials are fumed silica and glass fibres. In a few cases open-cell polymer foams, such as special polyurethane or polystyrene foams, are used.
VIP envelope materials
Gas impermeability is the main factor influencing the selection of envelope materials for VIPs. In terms of a VIP’s life expectancy, its impermeability to water vapour is also important. Furthermore, a low thermal conductivity is also vital in order to keep the thermal bridge effect as low as possible along the edges of the panels. Because of the mechanical loads that occur during construction, the envelope materials should also have sufficient puncture resistance.
The envelope materials used for thermos flasks are also generally suitable for flat VIPs. These materials are namely stainless steel, aluminium and glass. In combination with filler materials such as foams and fibres, only these materials achieve the required high gas impermeability. High gas impermeability is the requirement for durable products. Most manufacturers use aluminium-metallised high barrier plastic laminates, aluminium composite films and stainless steel films or sheets to provide the VIP envelopes.
优点
经过加工后，有热解二氧化硅芯的、干燥且彻底真空的绝热板的导热系数大约是0.004 W/（m•K）；而在环境压力下，这个系数是0.020 W/（m•K）。相比之下，常规的绝热材料的热导率一般在0.030和0.040 W /（m•K）之间。
真空隔热板技术可以提供:
绝热厚度超薄（10毫米至25毫米），在空间有限的应用中，增加了使用空间；
当正确安装和保护免受损害和渗透时有稳定、长效的隔热性能；
高性能隔热板，其热导率比其他常规的绝热材料（3 mW /（m•K）低8到10倍；
并且还有设计和施工方面的可塑性。
对投资回收期（PBP）的估算应当包括使用真空绝热板材料后节省的建筑面积。建筑材料必须有极长的使用寿命。因为当气体压力高于50到100 mbar时，VIPs的寿命即告终结；因此，许多研究和开发项目将重点放在了真空绝热板的包膜。加深对VIP结构的研究将可以使其服务周期扩大至几十年，甚至一个世纪之久。