01-11-2014, 03:08 PM
Abstracts: This paper work presents a theoretical and experimental analysis of the effect of condenser sub cooling on the performance of vapour-compression systems. It is shown that, as condenser sub cooling increases, the COP reaches a maximum as a result of a trade-off between increasing refrigerating effect and specific compression work. The thermodynamic properties associated with the relative increase in refrigerating effect, i.e. liquid specific heat and latent heat of vaporization, are dominant to determine the maximum COP improvement with condenser sub cooling. Refrigerants with large latent heat of vaporization tend to benefit less from condenser sub cooling. On the other hand, the value of COP maximizing sub cooling does not seem to be a strong function of thermodynamic properties. Experimental results R134a confirmed the trends observed during the numerical study. For a given operating condition, the system COP increased up to only 9% for R134a.