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 ...

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...

The examination of available vapor pressure data in the case of the methane, ethane, propane and butane halogenated refrigerants, allowed recommendations of standard equations for this property. In this study, three new models include a general correlation; a substance-dependent correlation and an artificial neural network (ANN) approach have been developed to estimate the saturated vapor press...

REFPROP: A Thermodynamic Properties Software Pro gram for Refrigerants and Their Mixtures

Due to the increased public concern over the role that chlorofluorocarbons CCFCs) play in depleting stratospheric ozone, a landmark international agreement , the Montreal Protocol, was signed in 1987 which regulated the production and consum ption of CFCs. More recently, several nations, most notably Canada, the Federal Rep ublic of Germany, Norway, Sweden, and the United States, have planned o...

The present work is the successful extension of an improved equation of state (EOS) to refrigerant fluids. The objective is the prediction of isothermal and saturated liquid densities of refrigerants. Two temperature-independent parameters appearing in the modified EOS are closely related to critical point properties of refrigerant fluids. Our results showed that, the proposed EOS can predict w...

In low-temperature processes, heat rejected from separation columns is removed by refrigeration systems to heat sinks (reboilers & pre-heaters), process streams, other <span style="font-size: 10pt; col...

This research is aimed to define , (1) the effects of refrigerant to the environment, (2) derive the eco friendly refrigerants by using software REFPROP, (3) describe the properties of refrigerant by mixing them in appropriate percentage, (4) reducing GWP and ODP by providing suitable substitute of CFC’s and HCFC’s refrigerants, (5) reducing the effect of refrigerant to the ODP. This analysis i...

Concerns about the impact on the environment of the refrigerants used in HVAC&R equipment are driving the development of alternative refrigerants with lower global warming potentials (GWPs). This paper reports the performance of DR-55 (now designated as R452B), DR-5A (now designated as R454B), and R32 in comparison to R410A at the component level from tests run on a 4 RT (14 kW) commercial unit...