STUDY ON PNEUMATIC CONVEYANCE OF COLD ENERGY USING A PHASE-CHANGE MATERIAL ENCLOSED IN SMALL SPHERICAL CAPSULES

小球囊内相变材料气力输送冷能的研究

基本信息

批准号：
63850044
负责人：
KUROSAKI Yasuo
金额：
$ 3.9万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63850044/
关键词：
Cold Energy Utilization of Latent Heat Spherical Capsule Pneumatic Conveyance Freezing of Supercooled PCM 冷熱輸送小球カプセル潜熱蓄熱空気搬送ポンプ動力冷熱損失

项目摘要

In this research, a refined cold-energy conveying system which reduces the required pump power was proposed and feasibility of the proposed system was discussed. Generally speaking, the conventional cold-energy conveying system, in which the cold-energy is directly transported by chilled brine, requires large pumping power especially when the amount of transporting cold-energy becomes large. In order to overcome the defect of conventional system, the proposed refined system utilizes the latent heat of a phasechange material (PCM) enclosed in a small capsule and the capsules are conveyed with gas flow.Small scale test loop of the proposed system was constructed to measure the conveying performances and cold-energy conveying performance of the proposed system was compared with the one of conventional system. The results snowed that, under the condition of identical cold-energy conveying rate, the proposed system requires less pumping power than the conventional one especially when the conveying rate of cold-energy becomes large (e.g. > 1 MW). In order to minimize the required pumping power, effects of shapes and sizes of the capsules on the pressure drop were also examined. The results that the pumping power required for vertical transportation of the capsules by using large capsules outer diameter of which is almost similar to the inner diameter of duct, and that spherical capsules require less pump power than cylindrical ones.In addition to these investigation, the investigators proposed a fluidized-bed-type freezer which make the PCM enclosed in a capsule vibrate to enhance freezing of supercooled PCM, and effects of amplitude and frequency of the vibration on freezing was examined. The results showed that the fluidized-bed-type freezer in which the capsules are fluidized with chilled gaseous medium is suitable for reducing supercooling of PCM enclosed in a small capsule.

在这项研究中，提出了一种减少所需泵功率的精细冷能输送系统，并讨论了该系统的可行性。一般来说，传统的冷能输送系统通过冷冻盐水直接输送冷能，需要较大的泵送功率，尤其是当输送冷量较大时。为了克服传统系统的缺陷，所提出的精制系统利用封装在小胶囊中的相变材料（PCM）的潜热，并通过气流输送胶囊。该系统的小规模测试回路被构建为测量所提出系统的输送性能和冷能输送性能，并将其与传统系统进行比较。结果表明，在相同冷能输送速率的情况下，所提出的系统比传统系统需要更少的抽气功率，特别是当冷能输送速率变大（例如> 1 MW）时。为了最大限度地减少所需的泵送功率，还检查了胶囊的形状和尺寸对压降的影响。结果表明，采用外径与管道内径几乎相似的大胶囊垂直输送胶囊所需的泵送功率，且球形胶囊比圆柱形胶囊需要的泵送功率更小。研究人员提出了一种流化床式冷冻机，该冷冻机使封装在胶囊中的相变材料发生振动，以增强过冷相变材料的冷冻，并检查了振动幅度和频率对冷冻的影响。结果表明，用冷冻气体介质对胶囊进行流化的流化床式冷冻机适用于减少封装在小胶囊中的相变材料的过冷度。