利用喷射器内激波效应提高跨临界CO2压缩/喷射制冷系统性能的机理研究

项目名称： 利用喷射器内激波效应提高跨临界CO2压缩/喷射制冷系统性能的机理研究

项目编号： No.51466001

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 能源与动力工程

项目作者： 李刚

作者单位： 广西大学

项目金额： 48万元

中文摘要： 激波对喷射器喷射性能有不可逆影响，设计上常避免或削弱之。但跨临界CO2压缩/喷射制冷循环中，恰当形态、强度和位置的凝结激波将有益于提高系统的制冷效率，因其提高了喷射器出口压力，减少压缩机的输入功，且大量凝结可获取更多的液态制冷剂，有效增加系统的制冷量。借鉴升压式汽水喷射器的技术，在跨临界CO2压缩/喷射制冷系统中，构建易于凝结激波形成的喷射器，揭示其激波的形成、形态及作用机理。主要研究内容包括：1、建立正确反映扩压性能的系统模型；2、喷射器混合室内源自主喷嘴出口处的激波形态特性研究；3、扩散室近混合室喉部促使凝结正激波的形成条件确定，喷射器内各区段激波对循环效率的影响分析；4、激波形态的实验获取。创新点：用简易有效的实验手段探索跨临界CO2工质在循环中相变规律；用喷射器混合室出口处凝结激波提高其出口压力和凝结量，阐明激波效应有益利用的最优控制策略，为环保制冷系统效率的提高开辟新途径。

中文关键词： 激波；喷射器；制冷系统；效率

英文摘要： The shock wave would be more influence on the performance of an ejector for its irreversible factor, so it is always avoided and weakened in the ejector design. However, the condensation shock wave with appropriate form, strength or location from the trans-critical carbon dioxide compression-eject refrigeration system will increase the efficiency of the cycle. Such a normal condensation shock can increase outlet pressure of the ejector, reduce the input power of the compressor, and output more liquid refrigerant for the large number of condensation. So it can effectively increase the amount of refrigerant to the cycle system. Learn from the vapor-liquid ejectors' working mechanism, the condensation shock wave will be generated in the ejector of trans-critical carbon dioxide compression/ejector refrigeration system instead of the traditional one. The characteristics and mechanism of internal flow in the ejector will be revealed. The main contents of the research: 1. the performance study of the shock wave in morphological characteristics from the primary nozzle in mixing section of the ejector; 2. Study of generation a normal condensation shock wave in the diffusion chamber near the throat of mixing section; 3. Analysis of effects of each region shock wave in the ejector to the cooling efficiency of the system; 4. Obtain the shock wave pattern in ejector by experiment.The phase transformation law from mixing process in the trans-critical CO2 medium of ejector will be explored and to avoid or weaken the influence in irreversible shock wave. The optimal control strategy to achieve the shock wave effective utilization will be proposed and elucidated. These will increase the efficiency of environmental refrigeration cycle system with a new solution.

英文关键词： shock wave;ejector;refrigeration system;efficiency