纳米制冷剂研究进展

纳米制冷剂是指以一定的比例和方式,在制冷剂介质中添加纳米级的金属或者非金属粒子从而形成的纳米流体,在强化换热、提高制冷系统效率等方面具有诱人的应用前景。介绍了以制冷剂为基液的纳米流体的研究现状,从热物性(包括导热系数和黏度)以及传热(包括池沸腾和两相流)方面对纳米制冷剂的研究进行了综述,指出了目前工作的不足以及未来研究的重点。     

重视氨制冷剂在制冷空调上的应用

重视氨制冷剂在制冷空调上的应用中国制冷学会曹德胜ＡｍｍｏｎｉａｔｈｅＣｈａｌｌｅｎｇｅｉｎＡｉｒＣｏｎｄｉｔｉｏｎｉｎｇＲｅｆｒｉｇｅｒａｔｉｏｎ￥ＣａｏＤｅｓｈｅｎｇ氨用作制冷剂在我国历史悠久,亦是用氨作制冷剂的应用大国,特别是冷冻冷藏,在５００余...     

制冷剂R142b热物性计算程序的一种简易可视化

根据国内外有关资料，对制冷工质R142b热物性数据进行了分析，得到了其热力性质简化计算模型；用Visual Basic 6．0对R142b热物性程序作了可视化研究，运算证明计算程序比较简单、实用，计算量小，精度能满足一般使用要求。     

神经网络模型在制冷剂物性参数计算中的应用

介绍采用BP，RBF和Elman神经网络计算制冷剂物性参数的方法。以R11，R134a和近共沸混合制冷剂R410A为研究对象，分别建立三种制冷剂的BP，RBF和Elman网络饱和物性参数计算模型。根据该模型由已知温度求各制冷剂在饱和气和饱和液状态下的其他物性参数值，通过与REFPROP软件计算结果进行对比，证明BP，RBF和Elman神经网络物性计算模型具有很高的精度，可以用于物性参数的计算，是一种新的物性计算方法。     

制冷剂物性参数的神经网络模型计算

建立了BP神经网络模型来计算制冷剂物性参数,并以近共沸混合制冷剂R410A为例计算其饱和和过热状态的物性参数值,得到了满意的结果.     

制冷剂特性数据解析与更新

介绍制冷剂主要的物理特性、安全性、环境特性等方面的数据，这些制冷剂包括过去广泛使用的、当前普遍使用的以及将来使用的。     

自然制冷剂在国外的研究进展

对国外自然制冷剂替代氟里昂的研究进行了综合归纳，根据其理论和实验的研究结果，分析了自然制冷剂的热力特性、安全性、应用前景及有关法规方面的问题。     

HFC32／HFC152a混合工质──热物性及替代CFC12冰箱的研究

选择制冷工质CFC12的替代物时,除厂ODP和GWP值以外,另一个不容忽视的因素是所选工质的热物性与CFC12相接近,从而达到降低制冷系统改造成本,节约能耗之目的。本文选用ODP值为零的 HFC32/HFC152a混合[质作为CFC12的替代物,用 PR状态方程进行了热物性分析,并在冰箱中作以实验,取得良好的结果。     

R290制冷剂在商用制冷柜领域的应用与研究

本文从比较制冷剂的物性参数入手,针对R290和R134a这两种制冷系统性能进行比较研究,分析了系统制冷罐注量影响因素与R290制冷剂的应用情况。     

R32制冷剂

自从1997年京都会议以后, R22和R410a都被认为是需要淘汰的制冷剂,世界各国都在寻找合适的替代制冷剂,并作为重要的任务。 R32被认为是一种有潜力的替代R22与R410a在空调器中使用的制冷剂。本文综述R32替代的可行性和它与R410a的性能比较。     

Literature Survey on Thermophysical Properties of Refrigerants

A bibliographic compilation is given on thermophysical properties of the environmentally acceptable hydrofluorocarbon blends R404A, R407C, and R410A. These refrigerant blends are still under investigation and meant to replace the transitional hydrochlorofluorocarbon R22 and the azeotrope R502. In a second part reliable formulations to calculate thermophysical-property surfaces of some selected well investigated fluids used in refrigeration are recommended. The fluids water, air, carbon dioxide, ammonia, R134a, R123, and R152a are subjects of that part.     

制冷工质热力性质计算及其可视化程序

对工程中常用的10种制冷工质的热力性质进行了分析计算，并采用visual Basic6．0编制出可视化的计算机程序，界面友好，计算结果与已有的图表吻合的相当好，并且在实际中得到应用。为制冷系统研究提供了基础手段。     

常用制冷工质热力性质计算数据库的开发

建立了包括湿空气、R22、R21、R12、Rll、R134a、NH3、H2O的热力性质计算数据库系统，其中热力性质计算包括温度、压力、密度、比焓、比熵、比容、汽化潜热。对R11、R12、R21、NH3、R134a的热力性质计算公式进行了修正，计算结果与文献中的数据进行比较，结果显示：数据库中除R134a和湿空气外，其他丁质的计算误差均小于0．8％，此外R22的热力性质计算程序已在制冷循环仿真模型中得到应用。     

制冷系统仿真中的工质热力性质计算程序

制冷系统仿真中必然用到工质热力性质计算程序,本文针对制冷系统中常用到的9种工质进行了热力性质分析,利用VB6.0编写了其计算程序模块,并在实际的制冷仿真系统中得到了应用,最终通过动力实验平台的测试,证实计算程序是合理的.     

制冷系统仿真中的工质热力性质计算程序

制冷系统仿真中必然用到工质热力性质计算程序,本文针对制冷系统中常用到的9种工质进行了热力性质分析,利用VB6.0编写了其计算程序模块,并在实际的制冷仿真系统中得到了应用,最终通过动力实验平台的测试,证实计算程序是合理的.     

Rapid Measurements of Thermodynamic Properties for Alternative Refrigerants with Vibrating-Tube Densimeter

More than 2000 PVT data in the liquid phase, vapor phase, and at saturation boundaries have been obtained for pure compounds of several alternative refrigerants. In addition, more than 1000 liquid-density data have been obtained for several binary and ternary mixtures. The alternative refrigerants measured in the present study include CF₃OCH₃ (trifluoromethyl methyl ether) and CF₃CF₂OCH₃ (pentafluoroethyl methyl ether), which are hydrofluoroethers developed by RITE (the Research Institute of Innovative Technology for the Earth, Japan), and typical hydrocarbons, such as propane, n-butane, isobutene, and their binary and ternary mixtures. The measurement uncertainties are estimated to be 3 to 7mK for temperature, 0.26kPa or 0.022% whichever is greater for pressure, and 0.07 kg ·m³ or 0.024% whichever is greater for density. The present measurement system took only a few minutes to get one PVT datum, and one or two days to complete all the measurements for a single fluid at temperatures from 240 to 380\,K and at pressures up to 7\,MPa. In addition, an empirical equation of state (EoS) for the liquid phase was developed on the basis of the present data, and the EoS nicely reproduces not only the present data but also existing data reported by other researchers.Paper presented at the Fifteenth Symposium on Thermophysical Properties, June 22–27, 2003, Boulder, Colorado, U.S.A.     

绿色环保混合制冷剂

介绍了环保混合制冷剂R-404A、R-407C、R-410A、R-413A和R-417A的性能、用途及我国目前的研究状况。     

Refrigerants and energy efficiency

Environmental concerns (i.e. ozone depletion and greenhouse warming) are forcing major shifts from traditional choices of refrigerant working fluids for individual systems and for specific applications. Energy efficiency has taken on new urgency to mitigate fossil fuel demands and the associated effects on greenhouse warming while allowing for future growth of refrigerant demand. Energy efficiency has thus become an increasingly important parameter and a key focus in the refrigerant selection process. Efforts to generically rank refrigerants with respect to their inherent thermodynamic efficiencies have thus far not proven to be very productive. Much conflicting information has surfaced as to the true impacts on energy demand of various candidate fluids. It is apparent that much more than a simple thermodynamic cycle efficiency is involved. Other factors may have an equal or even greater impact on the ultimate energy demands associated with any particular working fluid and/or system design. Even calorimeter testing may prove misleading in the absence of appropriate optimization. This paper discusses individual sources of inefficiency inherent in every real system and attempts to define key fluid characteristics associated with optimizing or degrading the effectiveness of individual system components and the overall system. Relative compressor efficiencies, heat transfer effectiveness, pressure drop impacts, etc., will be addressed.     

Solubility of Refrigerants in Various Lubricants

Solubility data of refrigerant/lubricant mixtures have been modeled with cubic equations of state (EOS): van der Waals (vdW), Soave-modified Redlich–Kwong (SRK), or Peng–Robinson (PR) types. The temperature dependence on the a parameter in the EOS is modeled with a common empirical function for pure refrigerants, including oils. For lubricants, a hypothetical oil (UniOIL) has been developed with universal oil EOS constants, and it is valid for any kind of lubricant oil. Only an average molecular weight is required for any type of oil. The mixing rules for the a and b parameters of EOS are more general than the ordinary van der Waals–Berthelot formula, and a justification of such mixing rules is discussed. The refrigerants studied are R-32, R-125, R-134a R-143a, R-152a, R-12, R-22, R-123 and R-13B1. The lubricants are naphthenic mineral (MO), alkylbenzene (AB/HAB), and polyol ester (POE) oils, as well as model compounds with pure component oils (hydrocarbons and POE). They are all analyzed with the UniOIL model. Good quality experimental solubility (PTx) data were selected from the literature and well correlated within their experimental uncertainties. All the cubic EOS (vdW, SRK, and PR) having the same type of mixing forms for the a and b parameters showed excellent fits to the experimental PTx data with essentially the same degree of accuracy. The results in this report are shown with the SRK type EOS.     

碳氢制冷剂在小型商用冷柜上应用分析

碳氢制冷剂作为天然制冷剂的一种,因其热物理性质与环保性能(ODP为0,GWP极低)俱佳而受到国内外学者的广泛关注。本文从碳氢制冷剂的循环热力学性能出发,对碳氢制冷剂应用于小型商用冷柜的理论和实验进展进行论述,并介绍了压缩机、润滑油以及其他相关方面的研究进展。研究表明,相比于小型商用冷柜中使用的传统制冷剂,碳氢制冷剂的单位制冷量和性能系数较高,排气温度较低,实际运行时冷却速度和噪声水平都有较大改善。然而,碳氢类物质具有可燃性。虽然小型商用冷柜中碳氢制冷剂充注量较小,但要使得碳氢制冷剂在小型商用冷柜中大规模应用,需要做相应的泄漏燃爆实验。