聚光集热器太阳能吸附制冷实验系统
Summary
以太阳能为动力, 研制了一种新型的吸附式制冷系统, 并进行了实验研究。水蒸气和沸石组成了吸附系统的工作副。本论文介绍了实验台的设置、操作程序和重要结果。
Abstract
为提高太阳能吸附式制冷的性能, 建立了太阳能浓缩集热器实验系统, 并进行了研究。系统的主要组成部分是吸附床、冷凝器、蒸发器、冷却子系统和太阳能集热器。在实验的第一步, 在封闭条件下, 太阳辐射加热了蒸汽饱和床, 导致床温升高, 压力增大。当床的压力变得足够高, 床被交换连接到冷凝器, 因此水蒸汽从床持续流动到冷凝器被液化。接下来, 床需要降温后解吸。在太阳保护条件下, 通过铝箔实现了循环水循环。随着床内水的不断循环, 床内的储热被取出, 床层压力相应降低。当床压在蒸发温度下下降到饱和压力下时, 就打开了蒸发器的阀门。大量水蒸气冲进床中, 被沸石物质吸附。随着蒸发器中水的大量汽化, 最终产生了制冷效应。实验结果表明, 无论吸附时间是否长, SAPO-34 沸石的 COP (系统性能系数) 和系统的 SCP (具体冷却功率) 均大于 ZSM-5 沸石;或更短。该系统的 SAPO-34 沸石产生了最大的 COP 0.169。
Introduction
随着传统蒸气压缩制冷技术的日益严重, 取代传统的制冷和绿色科技已成为近年来的热门话题。在这些绿色技术中, 太阳能吸附制冷已经引起了研究者的广泛关注。在低品位热能驱动下, 吸附式制冷系统具有环保、小巧、灵活等优点。这种吸附系统也可以用灯的能量来驱动, 例如由热设备排出的废热或来自车辆的发动机废气, 如胡et al所述。1
在吸附冷却系统中, 吸附床是关键部件。它的工作直接影响整个系统的性能。因此, 吸附床的设计是 Sutuki 所指出的最重要的问题。2 10 年前, 该平床主要用于吸附式冷却系统。3,4,5没有任何聚光装置, 平坦的床层温度通常较低, 因此系统的 COP 不理想。相比之下, 管状吸附床改善了 COP。据报, 该缔约方会议可由阿马尔et al.在撒哈拉以南地区达到0.216此外, 王et al.7开发了一种由连续热再生特性所区别的螺旋板吸附。新型吸附床的设计缩短了系统的循环时间。阿布-Hamdeh et al.8报告了其对带抛物线槽集热器的太阳能吸附式制冷系统的研究。他们的测试结果显示, 该系统的 COP 从0.18 到0.20 不等。El Fadar et al.9研究了一个与热管耦合的吸附式制冷系统, 并利用抛物线槽集热器对其进行了分析, 结果显示了最佳 COP 0.18。
为提高管状床的传热性, 考虑了翅片管吸附, 并对其强化效果进行了研究。Restuccia et al.提出了一种采用壳管式换热器形式的创新型床。10. 内翅片管涂有沸石层, 使金属表面与吸附剂材料之间的热/质量接触传递阻力降低。在15-20 秒的循环时间内, 系统产生了30-60 瓦特/千克的特定冷却功率的输出. et al.11表明, 增强的吸附与5-6 鳍可以显著减少吸附的热损失的气氛, 从而改善 COP 45%。Louajari et al.研究了翅片管吸附对太阳驱动系统性能的影响。12. 以活性炭-氨水为工作副, 证明了翅片吸附的循环传质比无翅片大。
在本研究中, 我们研究了一种改进的太阳能吸附式制冷系统, 采用了太阳能跟踪抛物槽收集器, 并部署了内部冷却隧道。该系统以 SAPO-34/ZSM-5 沸石和水蒸气为工作副, 在热力学和制冷方面表现出了有趣的特点。实验方法以及典型的测试结果将在本报告中介绍和讨论。
Protocol
Representative Results
Discussion
作为一种热力系统, 太阳能吸附式制冷装置的性能取决于系统的优化设计和合理运行。床的热供应和冷却方式都是保证系统工作正常运行的重要因素。水冷是由于水的对流换热强度高, 所以更倾向于空气冷却。吸附剂材料的导电性差通常决定了床的传热速率有限。为了改善床的传热, 许多测量都被认为是内部插入的翅片的增强结构。19硅胶是另一种受欢迎的吸附剂材料。如果在太?…
Declarações
The authors have nothing to disclose.
Acknowledgements
这项研究工作由中国国家重点基础研究项目 (No. 2015CB251303) 和中国国家自然科学基金 (No. 51276005) 主办。
Materials
| evaporator | home-made | finned heat exchange | |
| condenser | home-made | finned heat exchange | |
| evaporator water tank | home-made | volume:9L | |
| condenser water tank | home-made | volume:9L | |
| vacuum pump | Beijing Jing Rui Ze Xiang Instrument Co. Ltd. | rotation speed:1400 motor pover:370W | |
| condenser pressure sensor | Beijing Li Nuo Tian Sheng Instrument Co. Ltd. | 16P2623 | maximum:2200Pa |
| bed pressure sensor | Beijing Li Nuo Tian Sheng Instrument Co. Ltd. | maximum:2200Pa | |
| adsorption bed | home-made | cylundrical glass tube | |
| parabolic trough | home-made | high reflective aluminum sheet | |
| water pump | home-made | motor pover:250W, water head:8m | |
| water tank | home-made | volume:500L | |
| DRT-2-2 direct solar actinometer | Beijing Tian Yu De Technology Co. Ltd. | 03140132 | sensitivity:13.257μV/W•m2 |
| TBQ-2 solar pyranometer | Jinzhou Sunshine Technology Development Co., Ltd., China | 209079 | sensitivity:12.733μV/W•m2 |
| SAPO-34 zeolite | Langfang Peng Cai Co., Ltd., China | 20mm in length and 2.2mm in diameter | |
| ZSM-5 zeolite | Langfang Peng Cai Co., Ltd., China | 5.7mm in diameter |
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