采用自然复叠制冷-40℃低温冷柜的仿真设计

建立了自然复叠制冷系统稳态仿真模型,该模型用实验数据进行了验证,误差小于±5%.用仿真模型研究了采用非共沸环保混合制冷剂(R744/R717)自然复叠制冷-40℃低温冷柜的性能,分析了CO2浓度、冷凝器出口温度及压缩机排气压力对制冷系统COP的影响.     

高温工质用于木材干燥除湿的试验研究

对新混合工质HTR01用于木材除湿干燥系统进行了理论循环分析和灌注式替代R22的循环性能试验研究，结果表明HTR01的制热量虽低于R22，但性能系数、压缩机排气温度和功耗等循环性能指标以及除湿能耗比均优于R22，用于木材除湿干燥可以明显提高干燥速度，干燥质量好。     

采用新工质的单元式空调机参数化计算机辅助设计

介绍了采用新工质的单元式空调机参数化计算机辅助设计的方法、特点和内容、同时对采用新工质（R134a)和R22的单元式空气调节机的设计结果进行了分析比较，采用新工质的单元式空气调节机性能会达到或超过采用R11的单元式空气调节机。     

Measurements of Two-Dimensional Distribution of Refrigerant Concentration in EHL Film Using Micro FT-IR and Effect of Variation of Concentration on Oil Film Thickness

The dissolution of refrigerant into a lubricant causes a decrease in viscosity of the oil and it gives a large effect on the lubrication of sliding parts in a refrigerant compressor. This paper describes an application of micro FT-IR to measure the two-dimensional concentration distribution of refrigerant held in solution in the EHL film surrounded by the refrigerant gas and discusses the refrigerant concentration variation in the vicinity of the Hertzian contact area. In order to measure the concentration distribution, an apparatus which can observe the EHL film in a point contact in the refrigerant atmosphere was developed. The refrigerant concentration was measured using micro FT-IR through a CaF₂ window from outside of the apparatus with polyol ester as a base oil in an atmosphere pressurized with HFC-134a refrigerant gas. The results indicate that the concentration of HFC-134a refrigerant reduces in the inlet boost region of EHL contact and the Hertzian contact area but in the side region of Hertzian contact area it is greater than that in the bulk fluid. In addition, the effect of the variation on the oil film thickness is discussed.     

Advantages of CO2 compared to R410a refrigerant of tribologically tested Aluminum 390-T6 surfaces

Carbon dioxide (CO₂) is currently being investigated as a viable alternative refrigerant due to its environmental advantages. Much research is still needed regarding thermodynamic, tribological, and design issues, yet CO₂ is a promising environmentally friendly refrigerant. This study investigates the physical and chemical changes of aluminum alloy disks that occur with increased severity tribotesting in the presence of either R410a or CO₂ refrigerants while submerged in POE lubricant. Visibly and through surface profilometry, this study clearly shows that R410a environment results in increased disk wear compared to CO₂ environment. In addition, Auger Electron Spectroscopy analysis was conducted showing that the oxygen concentration tends to increase with testing duration for both R410a and, to a greater extent, CO₂ tested samples. When Auger data were compared for the R410a submerged in POE, CO₂ submerged in PAG, and CO₂ submerged in POE, the CO₂ tested samples had significantly higher oxygen concentrations. This indicates that CO₂ refrigerant is promoting a strong oxygenated layer, which reduces wear.     

制冷机型式对制冷剂替代的影响

讨论了不同类型制冷机的工作原理、应用场合、优缺点、传统工质、常用替代工质以及选择替代制冷剂时需要考虑因素的侧重点。研究表明:开启式制冷机应着重考虑替代制冷剂的安全性能;而封闭式制冷机应重点考虑替代制冷剂与材料的相容性以及替代制冷剂与润滑油的互溶性;对于活塞式制冷机而言,单位容积制冷量、单位容积耗功量、性能系数和化学稳定性是替代时应着重考虑的因素;对于螺杆式制冷机而言,替代制冷剂的单位容积制冷量、单位容积耗功量、性能系数和安全性能是主要因素;而对于离心式制冷机而言,替代制冷剂的分子质量、粘度、汽化潜热以及变工况性能则是主要因素。     

混合工质变容量调节技术及其应用

介绍了一种新的空调热泵系统容量调节方法——混合工质变容量调节，从原理、结构上分析了国内外提出的各类混合工质变容量系统的特点，指出各类方法能被实际应用所需解决的关键问题，从而为该类产品的实用化提供参考。     

涡旋压缩机研究概述

简述了涡旋压缩机发展历程以及在涡旋型线、平衡机构、热力学分析、工质替代、加工制造等方面的最新研究状况，并指出了在今后一段时间内涡旋压缩机的研究方向。     

可燃制冷工质的爆炸极限研究综述

从爆炸极限的定义、爆炸容器、点火方式、流动状态、选择性扩散等方面,阐述了实验研究的进展;从可燃物的爆炸极限预测方法出发,概述了估算研究的成果.到目前为止,实验测定的方法还没有统一的标准,理论估算的误差也比较大.指出了颇有争议性的问题和亟待研究的空白,并对进一步的研究工作提出了若干建议.     

关于二氧化碳作为低温载冷剂的探讨

大多数传统载冷剂的传热性能较差,低温时压力损失较大,因此系统的制冷性能较低。二氧化碳作为自然工质（ODP=0,GWP=1）,无毒、不易燃,同时,由于具有较好的输运性质,其在管道内的压力损失较小。所以,二氧化碳被选作载冷剂,能很好地改善系统的制冷性能。本文通过分析说明二氧化碳作为载冷剂必将拥有广阔的应用前景。