【作者】 赵鹏；

【导师】 王铁军；

【作者基本信息】 合肥工业大学 ， 制冷与低温工程， 2010， 硕士

【摘要】 高温空调通常在宽温度范围和高温工况下运行,常用的中温制冷剂难以获得良好的空调特性。探求环境友好且热力性质良好的制冷剂成为解决高温空调技术难题的关键因素之一。本文就探索适合高温空调运行特性的制冷剂而展开相关研究工作。首先分析了非共沸混合工质R22/R142b的性质,指出高温空调使用R22/R142b在理论上是可行的,其环保性质和热力性质都较理想。利用R22/R142b热力性质,对原R12高温空调系统主要部件进行了校核分析。之后,用实验和仿真的方法探究了高温空调样机性能参数随R22/R142b质量比例变化的规律,发现混合工质质量比为5/5～7/3时,空调系统在35～75 o C较宽的环境温度范围可获得较理想的制冷量,且变化平坦,而排气温度和排气压力这两个安全指标也在可接受的范围内。实验分析了空调样机的最佳充灌量,结果表明制冷剂充灌量在2.65kg左右时空调的运行性能较好。本文对高温空调制冷剂替代问题的研究,为在技改费用较低的前提下对高温空调的改进提供了清晰的思路和能较快实现的方法。而本文采用的研究方法和实验及仿真结果对高温热泵的研究同样具有一定的参考价值。更多还原

【Abstract】 High temperature air-conditoners often run over a wide temperature range and in high temperature work conditions,so some commonly used mid-temperature refrigents are not suitable for high temperature any longer.It is a key facter to search for a proper kind of refrigent to solve the problems of developing and manufacturing high temperature air-conditioners,which is environmentally friendly and has good thermodynamic properties.The major work of this thesis was to find a proper kind of refrigent which is suitable for circulating in high temperature air-conditioners.Non-azeotropic mixture R22/R142b’s properties were analyzed in this thesis at first, and it was found that it is feasible for high temperature air-conditioners to use in theory,and not only the thermodynamic properties of it are fairly good but also it is environmentally friendly. By using R22/R142b’s thermodynamic properties, the main components of the high temperature air-conditioners which originally used R12 as working fluids were checked and analyzed. Then the variation of the running performance with different mass fractions was studied by method of experiment and simulation.It was found that the cooling capacity is fairly high and changes smoothly over a wide temperature range of 30～75 o C when the mass fractions of R22/R142b range from 5/5 to 7/3 ;Besides, both the exhaust temperature and the exhaust pressure are not so high that they can damage the air-conditioner.Meanwhile,The optimal refrigerant charge was also tested in high temperature work conditions in this thesis,as a result, the sample machine ran relatively well when the refrigent charge was about 2.65kg.Good idea and methods for the improvement of high temperature air-conditioners ,on the premise of relatively low cost in the technological transformation ,were provided through the study on the refrigerant replacement in high temperature air-conditioners in this thesis. Reference was also provided for the study on high temperature heat pumps by the research method and the results of experiment and simulation in the thesis.更多还原