论文部分内容阅读
本文对一种复合型的绝热系统进行了研究,其组成为一层闭孔型硬泡沫和超绝热层的外覆盖层。在地面条件下硬泡沫可以消除空气或吹洗氮气的冷凝。超绝热层的多层辐射屏在空间停泊阶段,通过微孔排出所包含的气体后,就为贮箱提供所必需的热隔绝。用平板热量计对各种类型硬泡沫的低温热传导性进行了研究,此外对热收缩及气体渗透性也作了研究。并且测量了粘结剂对泡沫的影响和在低温下的粘结强度。硬泡沫是用特殊的工艺方法固定到客积为260升至1000升的模型箱圆筒和椭球底上,并在液氢条件下做了试验。振动稳固性通过一个加注液氖的专门绝热箱试验而得到证实。超绝热层用多层聚酯镀铝箔制成。各层的间隔,不同的皱曲程度,穿孔度,线和面压缩和残余气体压力对有效热传导的影响是用平板和扁箱热量计来测量的。此外对于超绝热层固着于金属箱上的各种安装技术都作了试验,过度重迭、缝合与渍通等缺陷的影响也都作了测量。箔的穿孔度由模拟发射状态下的压力降实验来确定。a_s/ε值用日光模拟法在超绝热层的小样件表面上作了测量。最后,对所选的一种复合绝热系统,使用各种缩比尺寸直至1000升大小的实验贮箱,用液氢和液氮在真空和地面条件进行实验来证实它的效力和复现性。此外,一种氦气吹洗系统已被证实在一定的环境下代替刚性泡沫绝热可能是有利的。
In this paper, a composite insulation system has been studied, which consists of an outer cover of a closed cell rigid foam and an insulating layer. Hard foam can eliminate the condensation of air or purge nitrogen under ground conditions. The multi-layer radiating screen of the ultra-adiabatic layer provides the necessary thermal insulation of the tank after it has expelled the contained gas through the micropores during the parking phase of the space. The low-temperature thermal conductivity of various types of hard foams was investigated using a flat-panel calorimeter, and thermal shrinkage and gas permeability were also investigated. The influence of the binder on the foam and the bond strength at a low temperature were measured. Hard foam is fixed by a special process to the model cylinder and ellipsoid with passenger volume of 260 to 1000 liters and tested in liquid hydrogen. Vibration stability was confirmed by a dedicated insulated box test of liquid neon. Insulation layer with multi-layer aluminum foil made of polyester. The effect of layer spacing, different degrees of buckling, perforation, line and surface compression, and residual gas pressure on effective heat transfer is measured using flat and flat box calorimeters. In addition, a variety of installation techniques have been tested for the application of an ultra-adiabatic layer to a metal box. The effects of excessive overlap, stitching, and stains are also measured. The perforation of the foil is determined experimentally with the pressure drop under simulated emission conditions. The a_s / ε value was measured on the surface of the small sample of the ultra-thermal layer by solar simulations. Finally, for a selected composite thermal insulation system, various sizes of experimental storage tanks up to 1000 liters in size were used to verify their efficacy and reproducibility using liquid hydrogen and liquid nitrogen in vacuum and in ground conditions. In addition, a helium purging system has proven to be advantageous in certain circumstances to replace rigid foam insulation.