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题名	旋转式室温磁制冷技术研究; 旋转式室温磁制冷技术研究
作者	1张征,电工研究所
学位类别	博士
答辩日期	2007-03-23
授予单位	中国科学院电工研究所
导师	1顾国彪,电工研究所
关键词	磁热效应 永磁体 旋转式室温磁制冷机 磁热力循环 magnetocaloric effect permanent-magnet rotating room temperature magnetic refrigerator magnetocaloric cycle
其他题名	旋转式室温磁制冷技术研究
中文摘要	长期以来，制冷手段基本局限于一般的机械式气体压缩循环制冷机，这类制冷机制冷效率比较低，只能达到卡诺循环效率的5%～10%，且工作介质一般为含氟氯烃类（CFC）等化合物，这些工质会破坏大气臭氧层并释放产生温室效应的气体，严重影响人类的生存环境，因此，寻求一种新型高效、环保的制冷技术成为制冷行业的一个研究方向。磁制冷技术作为一种新型的制冷方法，具有无污染、无噪声、可靠性高等优点，它不同于传统的依靠气体的压缩和膨胀使工质发生相应的改变而实现制冷那样，需要使用氟氯烃类（CFC）化合物和应用结构复杂的气体压缩机等设备，而只要利用磁性材料的磁热效应，通过磁化和去磁过程的反复循环达到制冷的目的，而且制冷效率比较高,可达卡诺循环效率的30%～60%。因此，磁制冷技术被称为一种绿色环保的制冷技术而迅速地发展起来，近年来尤其是室温磁制冷技术已成为各国研究热点。本文以研制旋转式室温磁制冷样机为目标，实现磁制冷机室温制冷效果实验研究的目的，为此开展了以下磁制冷理论基础、样机研制以及实验研究工作。 本文首先从磁制冷的热力学机理、磁热效应的基本理论以及磁热力循环系统分析等几个方面阐述了室温磁制冷技术的理论基础，分析了不同结构的室温磁制冷机存在的优缺点，探讨了室温磁制冷材料的选择和制备技术以及研究方向，为旋转式室温磁制冷样机研制提供了充分的理论基础和设计依据。 依据旋转式室温磁制冷机结构要求，本文设计加工了一台结构紧凑、具有高磁场强度工作气隙的永磁体，并对该永磁体进行了简单地计算和实验研究，磁场分布的计算结果和实验情况基本吻合。永磁体可为磁工质提供1.45特斯拉的工作磁场，该磁场强度可以满足在实验室展示磁热效应特性和室温磁制冷特性等一些演示性教学实验。 本文在介绍磁制冷机各部件结构设计一般原则的基础上，研制加工出一台旋转式室温磁制冷样机。给出了该样机结构的详细设计方案，并指出各个部件在结构设计中应注意的问题，其中重点对镶嵌有磁工质的转盘和用于与换热流体进行热交换的套管结构进行了设计，在一定程度上有效地解决了旋转式室温磁制冷机结构复杂、加工精度要求过高和换热流体密封困难大等一些难题。 利用本文设计加工的旋转式室温磁制冷样机，进行了一些针对磁热效应特性和制冷效果特性的实验研究。分析了不同换热液体流量、不同的转盘转速以及换热液体的入射角度对磁制冷机制冷能力的影响。实验结果显示：该样机在没有通换热液体的情况下展示了磁工质的磁热效应现象，获得了1.63K的最大温度变化；在采用保温泡沫做了一定的绝热包裹处理后，获得了2.87K的冷热端温差。 最后，结合国内外研究成果，本文对影响磁制冷循环的不可逆因素进行了总结，提出了继续深入研究旋转式室温磁制冷机的下一步工作内容，并指出了需要讨论的问题、建议以及室温磁制冷技术的研究难点和展望。 In recent years, many experts have paid much attention to the magnetic cooling technology because the refrigerant material we used nowadays in refrigerators and air conditions may induce many damages such as toxicity, ozone depletion or global warming hazard. Magnetic refrigerators have many advantages over the currently commercial devices, which extract heat from vapor using the compressor: they do not use hazardous or environmentally damaging chemicals, such as chlorofluorocarbons. And the magnetic field could be supplied by electromagnet, superconductor or permanent magnet, which has no need for compressors with movable components. The efficiency of magnetic refrigeration could be 30～60% of Carnot cycle, whereas the efficiency of vapor compression refrigeration was only 5～10% of Carnot cycle. Therefore, the magnetic refrigeration techniques have recently been demonstrated as a promising alternative to conventional vapor-cycle refrigeration, especially at the near of room temperature range, which has attracted many experts and became the international hotspot. In order to manufacture a rotating room temperature magnetic refrigerator prototype and obtain a certain cooling effect, this thesis made theoretical approaching, prototype development and experimental work, which was focused on the following aspects: Firstly, the basic theory of the room temperature magnetic refrigeration technology which derived from the thermodynamics and magnetocaloric effect theoretics were narrated in this paper. In addition, the traits of different structure magnetic refrigerators were analysed and the produce technologies of room temperature magnetic materials were discussed, which supplied theoretical and design groundworks for investigating rotating room temperature magnetic refrigerator prototype. Secondly, a permanent magnet which possess high magnetic field in work air-gap was designed according to the demands of rotating magnetic refrigerator structure. Moreover, some numerical calculations and experiments were carried out in this paper. The experimental data showed that the design value was accorded with the actual measure field strength approximately. The magnetic density in the center of working air-gap was up to 1.45T, which was a considerable value to the permanent magnet and could meet the need to be applied in the laboratory as a whole. Thirdly, the design principle of different structure components were introduced respectively and based on it a rotating room temperature magnetic refrigerator prototype was designed and manufactured. Meanwhile, the blue print of prototype structure were given in detail and the problem should be paid attention to in design process were pointed out. And the emphases lied in the structure design of turnplate and cannula, which resolved some problems to rotating room temperature magnetic refrigerator such as structure complexity, rigorous require for machining precision and seal means in a certain extent. Fourthly, the rotating room temperature magnetic refrigerator prototype was designed and manufactured so as to carry out some experimental research which aimed to the magnetocaloric effect of gadolinium and refrigeration characteristics of the magnetic refrigerator prototype. The factors which influenced the capability of refrigeration such as the flux of liquid, the rotate speed of turnplate and the angle of incidence to liquid were studied. And the result of the experiments showed that 1.63K was gotten as the temperature difference to magnetocaloric effect when no adiabatic measure was adopted. Furthermore, 2.87K as the maximal temperature difference was got from the prototype on the condition that a certain adiabatic wrappage was used. Lastly, some achievements of many experts had been taken into account. Meanwhile, the nonreversible factors which influenced the magnetic refrigeration cycle were summarized and brought forward the next step work for investigating rotating room temperature magnetic refrigerator. In addition, the problems, suggestions and expectations to the technology of room temperature magnetic refrigeration were pointed out in the end of thesis.
语种	中文
公开日期	2010-10-18
页码	135
分类号	TM3;TM5
内容类型	学位论文
源URL	[http://ir.iee.ac.cn/handle/311042/6682]
专题	电工研究所_其他部门_其他部门_博士学位论文
推荐引用方式 GB/T 7714	1张征,电工研究所. 旋转式室温磁制冷技术研究, 旋转式室温磁制冷技术研究[D]. 中国科学院电工研究所. 2007.

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