【作者】 陈琪；

【导师】 冯仰浦； 陈国邦；

【作者基本信息】 浙江大学 ， 制冷及低温工程， 2002， 硕士

【摘要】 J-T节流制冷机以其结构简单、可靠性高、适应性强的特点，在能源、军工、空间、生物、医疗和生命科学等领域得到了日益广泛的重视和应用。采用混合工质的J-T节流制冷机在热效率上比纯质有大幅度的提高，本文从理论和实验两个方面分别对开式的J-T快速节流制冷机系统和用空调压缩机驱动的混合工质闭式J-T节流制冷循环进行了研究。 多元混合工质J-T节流制冷机涉及许多分支学科，其内部工作机理十分复杂，本文着重对以下几个方面的问题进行深入研究，取得了一些理论进展和实验结果，其要点如下： 1．综述了混合工质J-T节流制冷循环的发展史及国内外研究现状，采用立方型状态方程对含氮混合工质的汽液相平衡和热力性质进行了计算，并在此基础上建立了J-T节流制冷系统各部件的物理模型，进行了系统的设计计算； 2．阐述了混合工质热交换器的设计方法，对翅片管绕管式换热器(Hampson型)进行初步设计； 3．阐述了混合工质J-T节流制冷机的工作原理，研究单纯工质和混合物工质的节流效应，比较混合工质节流制冷机与纯工质节流制冷机分析方法上的一些不同，分析了采用混合工质提高节流制冷机热效率的机理； 4．混合工质J-T节流制冷机的试验研究及分析，对开式系统的快速J-T节流制冷机进行试验研究；对单级油润滑的空调压缩机驱动的氮烃类混合工质J-T节流制冷机进行了重点试验研究。 实验结果验证了理论模型的可靠性，同时也发现系统设计及运行中存在的问题，为系统以后进一步的改进指明了方向。此外，由于混合工质种类以及混合工质J-T节流制冷机工作模式的多样性，有关混合工质J-T节流制冷机系统中的热力问题和技术问题还需要作进一步的深入研究。更多还原

【Abstract】 Joule-Thomson (J-T) refrigeration cycle has many applications in the field of energy, national defence, biomedical storage and cryosurgery, due to its simple structure, reliable performance and low cost. With mixed-refrigerant, the thermodynamic efficiency of J-T cooler can be greatly improved. In this thesis, an open fast-cool-down J-T cooler driven by the high pressure pure nitrogen is investigated, and we also proposed mixed-refrigerant J-T coolers driven by a single stage oil-lubricated air-conditioning compressor. These two systems were studied both in theory and experiment.The internal working process of the mixed-refrigerant J-T coolers is considerably complicated, therefore the working mechanism of the J-T coolers has not been well understood. The author solved the following thermodynamic problems in this dissertation:1. We reviewed the historical development of J-T refrigeration cycle and its current study at home and abroad. Using cubic equation of state, the vapor-liquid equilibrium of cryogenic mixtures containing nitrogen and hydrocarbons and their thermodynamic properties were calculated. Based on these calculations, the system and its components were designed.2. The analysis and design method for small miniature counter flow heat exchangers with mixed-refrigerant is presented. Under the guidance of the above method, the type of Hampson heat exchanger for mixed-refrigerant J-T coolers is designed.3. According to the working theory of the Joule-Thomson throttle coolers, the characteristics of mixed refrigerant and thermodynamic performance of a mixed-refrigerant J-T refrigeration cycle are analyzed systematically. The essence of improving thermodynamic efficiency of J-T coolers with mixed-refrigerant is revealed in-depth.4. An open fast-cool-down cycle J-T cooler and a small closed cycle J-T cooler are investigated both in theory and experiment.The obtained theoretical and experimental results are very meaningful, the experimental results verified the theoretical model and also showed some problems during design and operation. However, many thermodynamic problems are not solved and understood thoroughly, and they are needed to study further.更多还原