太阳能喷射式制冷系统中蒸汽喷射器性能的数值模拟

发布时间：2018-03-04 20:45

本文选题：太阳能利用　切入点：喷射式制冷　出处：《青岛大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着经济的发展,人类对能源的需求越来越大,加上开发消耗常规能源带来的一系列环境问题,使得新能源开发利用受到越来越大的关注。其中,太阳能因其资源丰富、无需运输、对环境无任何污染等优势成为了各行业开发利用的重点。太阳能喷射式制冷具有优于其他制冷方式的特点,该系统操作简单,几乎无运动部件,运行稳定,使用寿命长。所以,本文针对太阳能喷射式制冷系统展开研究,以制冷系统中常用的制冷剂为工质,分析了该系统的整体性能,并对其中的喷射器进行了三维数值模拟。本文首先从太阳能喷射式制冷系统性能、蒸汽喷射器的二维与三维数值模拟等方面综述了其在国内外的发展与研究现状,提出了本文研究的主要内容；然后理论上分析了该系统的性能随制冷剂种类、工作参数的变化趋势；接着根据索科洛夫阐述的蒸汽喷射器设计的原理和方法,对喷射器进行了结构设计,并利用FLUENT软件进行三维数值计算。结果表明：喷射器的喷射系数随着工作流体和引射流体的压力升高而增大,随着出口压力的升高而减小；而且随着工作流体压力的升高,喷射系数的增大趋势逐渐减弱；引射流体过低或混合流体出口压力过高时,工作流体都不能引射被引射流体,即喷射器不能工作;喷嘴扩张角在8-16°变化时喷射系数比较理想；喷嘴的收缩角在30～40°范围内变化时喷射系数较好；喷射器的喉部截面积比对喷射系数影响很大,该值过低时喷射器不能工作,过大时喷射系数迅速降低；流线型结构可以提高喷射器性能,它的弯曲程度对喷射器性能影响很小；喷嘴出口带导流段有助于喷射器性能的提高。
[Abstract]:With the development of economy, the demand for energy is increasing. In addition, a series of environmental problems caused by the development and consumption of conventional energy make the development and utilization of new energy receive more and more attention. Among them, solar energy is rich in resources. No need to transport, no pollution to the environment and other advantages have become the focus of development and utilization of various industries. Solar ejector refrigeration has the advantages of simple operation, almost no moving parts, stable operation and long service life. Therefore, the research on solar ejector refrigeration system is carried out in this paper. Based on the refrigerant commonly used in the refrigeration system, the overall performance of the system is analyzed, and the ejector in the system is numerically simulated. Firstly, this paper summarizes the development and research status of solar ejector refrigeration system from the aspects of performance, 2D and 3D numerical simulation of steam ejector, and puts forward the main contents of this paper. Then the change trend of the system performance with the refrigerant type and working parameters is analyzed theoretically, and then the structure of the ejector is designed according to the principle and method of steam ejector designed by Sokolov. The results show that the injection coefficient increases with the pressure of the working fluid and the ejector fluid, decreases with the increase of the outlet pressure, and increases with the increase of the working fluid pressure. The increasing trend of the jet coefficient gradually weakens, when the ejection fluid is too low or the outlet pressure of the mixed fluid is too high, the working fluid can not be ejected into the ejected fluid, that is, the ejector cannot work, and the jet coefficient is ideal when the nozzle expansion angle varies from 8 to 16 掳. The jet coefficient is better when the constriction angle of the nozzle changes in the range of 30 掳40 掳, and the throat sectional area of the injector has a great influence on the jet coefficient. When the value is too low, the ejector can not work, and the jet coefficient decreases rapidly when the nozzle is too large. The streamline structure can improve the performance of the ejector, and its bending degree has little effect on the performance of the ejector, and the nozzle outlet with the diversion section is helpful to improve the performance of the ejector.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB657

【参考文献】