Title of Document: INVESTIGATION OF HOUSEHOLD REFRIGERATOR WITH ALTERNATIVE LOW GLOBAL WARMING POTENTIAL REFRIGERANTS Daniel Thomas Leighton, Master of Science, 2011 Directed By: Professor Reinhard Radermacher, Mechanical Engineering Steady-state and transient thermodynamic models of the refrigeration system were created in order to predict the performance of household refrigerators using diffe...

The observation of a giant magnetocaloric effect in Gd5Ge1.9Si2Fe0.1 has stimulated the magnetocaloric research in the last two decades. However, the high price of Gd and its proclivity to corrosion of these compounds have prevented their commercial use. To reduce raw materials cost, transition metal-based alloys are investigated to replace rare earth-based materials. Environmental consideratio...

Many fluids of hydrocarbon derivatives were used as working fluids in refrigeration and air conditioning during the past few decades. The phase out of chlorofluorocarbons and hydrochlorofluorocarbons has initiated research on finding an alternative working fluid for the existing. In this article, some working fluids with zero ozone depletion potential have been assessed for their suitability as...

Fluorinated hydrocarbon refrigerants have especially in Europe been drawn into the focus of the public debate concerning the background of reducing greenhouse active substances. This debate concentrates mainly on the GWP (Global Warming Potentials) properties of the substances. To step forward from a material based discussion to a useful dialogue about substances in their respective application...

Performance of a reciprocating refrigerator compressor with mixed-refrigerants (MR) was investigated experimentally. The current, standard methods of testing compressors and presenting performance data were found unsuitable for MR, and a new experimental apparatus was designed for a ·direct flowrate measurement with MR. Representative test data for Refrigerant R-12 and for a mixture of R-22/R-1...

Recent interest in natural refrigerants has created a new impetus for studies of CO2 as a working fluid in vapour compression systems for refrigeration and air conditioning. Two major drawbacks to its use are the very high pressure differences required across the compressor and the large efficiency losses associated with the throttling process. To overcome the throttle losses, a number of propo...

A study on the degradation of both halogenated and non-halogenated polymers has been made by x-ray photoelectron spectroscopy two different types common place spectrometer. The results herein are compared with index Beamson Briggs, a notable difference was observed. effects neutraliser spot size kinetics explored lead to simple recommendations for successful analysis damage-susceptible polymers.

Compression of pure refrigerants in the two-phase flow region has a number of advantages for the performance of vapor compression systems. Compressors may be lubricated by liquid refrigerant so that the process side of the cycle is not contaminated by lubricant. The compression process can be realized in the two-phase region preventing superheating with its associated irreversibility losses. Th...

The present paper summarizes the activities at LTT-Erlangen on the field of thermophysical properties research for pure refrigerants and refrigerant mixtures. For the characterization of their thermophysical properties dynamic light scattering (DLS) has been intensively applied as a key tool during the past two decades. Beside a representation of the essential features of DLS for the determinat...

Two phase flow in a horizontal tube has widespread applications, particularly in the condensers of refrigeration and air conditioning systems. Pressure drop prediction is especially important for condensers because the local condensing temperature is a function of local pressure, affecting the mean temperature difference in the heat exchanger. In the present analysis, two phase flow is treated ...