磁场对HCFC-141b制冷剂水合物生成及分解过程的影响研究
文献类型：学位论文
| ; | |
| 作者 | 刘勇 |
| 学位类别 | 硕士 |
| 答辩日期 | 2003 |
| 授予单位 | 中国科学院广州能源研究所 |
| 授予地点 | 中国科学院广州能源研究所 |
| 导师 | 樊栓狮 |
| 关键词 | 气体水合物 磁场 引导时间 水合率 分解 |
| 其他题名 | EFFECTS OF MAGNETIC FIELDS ON HCFC-141b REFRIGERANT GAS HYDRATE FORMATION AND DECOMPOSITION PROCESS |
| 学位专业 | 热能工程 |
| 中文摘要 | Gas hydrate are crystalline compounds formed (usually above 0°C) by water, reacting with some gases or volatile liquids (hydrate former). Guest molecules, such as gas or volatile liquid molecules, are enclosed firmly inside the host cavities and act with water molecules in weak Van der Waals force. Gas hydrate usually includes natural gas hydrate, refrigerant gas hydrate and CO2 gas hydrate. Refrigerant hydrates can be formed above 0°C, and their crystallization is similar to ordinary ice, so it is also called "warm ice". Because the phase change temperature of the refrigerant gas hydrate is between 5 and 12°C and with a formation heat which is close to that of ice, it can be a substitute of cool storage medium for air-conditioning systems. The performance and applicability of the gas hydrate cool storage system can have a great superiority to that of the ice. To develop a cost-effective cool storage system for air-conditioning, a low-pressure gas hydrate cool storage medium should be employed. Unfortunately, those low-pressure refrigerants, such as Rll and HCFC-141b, are comparatively inactive in gas hydrate formation. In ordinary condition, guest species and water phases are scarcely mixed and the diffusion speed of different components through the interphase is very slow. Consequently, one has a very long induction time of reaction and a quite slow growth speed, even with surfactants and nucleate seeds added. Therefore, if refrigerant hydrates are employed as a medium of thermal energy storage t in engineering application, a rapid and uniform formation of gas hydrate will be the key for technical success. Electrical and magnetic fields may affect significantly the equilibrium formation conditions and growth kinetics of many crystallization process. Currently, there are no reliable experimental and theoretical data about the effect of these fields on gas hydrate formation. Makogon1561 indicated the effect of a stationary magnetic field on density and structure of hydrates. Denser hydrates with more regular structure may be formed under the influence of magnetic field. At present, there are no literatures about the effects of magnetic fields on refrigerant gas hydrate formation and decomposition processes. In this paper, the effects of a magnetic field on the formation process of HCFC-141b refrigerant gas hydrate are depicted experimentally. The visualization of the refrigerant gas hydrate formation was carried out and the morphology of the hydrate crystallization process in the applied magnetic field was studied. It is found that the orientation and growth region of gas hydrate are altered when subjected to different ways of the magnetic field; the induction time of hydrate crystallization can be shortened extremely under influence of the field: e.g. it can be shortened to 40min from 9h; the hydrate formation mass can be enhanced considerably; and the hydration rate can arrive at 100% in some instances. Meanwhile, the relations of induction time and hydration rate changed with magnetic pole and intensity and the number of iron wires are depicted. It is also found throughthe experiment that magnetic field can affect the HCFC-141b refrigerant gas hydrate decomposition process, and the decomposition temperature is elevated about Ik, comparing to that without magnetic field. The mechanism that magnetic field affects refrigerant gas hydrate formation and decomposition process is discussed. |
| 语种 | 中文 |
| 公开日期 | 2011-07-06 ; 2011-07-08 |
| 页码 | 65 |
| 源URL | [http://ir.giec.ac.cn/handle/344007/3857]  |
| 专题 | 中国科学院广州能源研究所 |
| 推荐引用方式 GB/T 7714 | 刘勇. 磁场对HCFC-141b制冷剂水合物生成及分解过程的影响研究, EFFECTS OF MAGNETIC FIELDS ON HCFC-141b REFRIGERANT GAS HYDRATE FORMATION AND DECOMPOSITION PROCESS[D]. 中国科学院广州能源研究所. 中国科学院广州能源研究所. 2003. |
入库方式： OAI收割
来源：广州能源研究所
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