We apply a modified scaling of viscosity with residual entropy in a manner analogous to that proposed by Rosenfeld (1977). We consider the viscosity-entropy scaling for a reference fluid (refrigerant R124 (1-chloro-1,2,2,2tetrafluoroethane) ), and demonstrate that the viscosity for many other refrigerants scales with residual entropy in a similar manner. Finally, we use a corresponding-states f...

Yuji Yoshida shigeo suzuki Yuji Mukai Kazuo Nakatani Katsuhiko Fujiwara* Matsushita Electric Industrial Co., Ltd. Central Research Laboratory 3 15 Yagumo-Nakamachi Moriguchi, Osaka 570, JAPAN *Air-conditioner Division The use of mixed refrigerants for heat-pump cycles h ave attracted the attention of the International Energy Agency as an important subject of heat-pump technology and its re sear...

The impact of man-made chemicals on the environment, and in particular, the ozone layer, has been investigated over the last 20 years. The phaseout of CFCs under European Regulations and the Montreal Protocol has already taken place and HCFCs are set to follow. A wide range of alternative refrigerants with zero ozone depletion potential have already been developed as replacements for the refrig...

The given paper is aimed at constructing the general circuit of heat processes in a semihermetic reciprocating refrigerant compressor as a basis of application of new ecology-friendly refrigerants as well as optimizing design parameters of compressor. While performing this work the following problems were solved: 1. Experimental research of heat processes in a semihermetic refrigerant reciproca...

Air conditioning control systems are commonly installed in restaurants, commercial buildings, office buildings and institutional buildings in Hong Kong. The systems invariably involve the use of fans for moving the air, filters for cleansing, ducts for air distribution, a control system for regulating the amount of heating or cooling automatically and a refrigerating plant connected to the heat...

There is no single perfect refrigerant for diverse air conditioning, refrigeration, and industrial applications. The predominant halocarbons (CFCs, HCFCs, and HFCs) combine excellent efficiency and safety with acceptable costs. However, they contribute to ozone depletion potential (ODP) and/or global warming potential (GWP). The Montreal Protocol has eliminated ODP by requiring replacement of C...

The world-wide agreement to restrict the use of chlorofluorocarbons (CFCs) and hydrofluorocarbons has prompted recent research exploring the possibilities of replacement refrigerants, particularly those occurring naturally in the environment. One such natural refrigerant, carbon dioxide, has been shown for particular applications to have a COP which is competitive with current refrigerants. How...

Transient simulations of refrigeration cycles are crucial for evaluating new refrigerants. Previously developed transient simulation tool was capable of simulating refrigeration systems using refrigerants R22 and R134a and was validated with experimental data; however, incorporating non-traditional refrigerants such as R744 (carbon dioxide) change the cycle operation beyond the capabilities of ...

In designing of condensers, the prediction of pressure drop is as important as the prediction of heat transfer coefficient. Modeling of two phase flow, particularly liquid – vapor flow under diabatic conditions inside a horizontal tube using CFD analysis is difficult with the available two phase models in FLUENT due to continuously changing flow patterns. In the present analysis, CFD analysis o...

The blends formed mixing hydrofluorocarbons (HFC) and hydrocarbons (HC) can be classified as semi-natural refrigerants since, by optimizing the composition, it is in principle possible to adapt basic features such as GWP, TEWI and flammability to the industrial and environmental requirements. However, the energetic efficiency must be competitive with the traditional refrigerants. To evaluate th...