Librería Samer Atenea
Librería Aciertas (Toledo)
Kálamo Books
Librería Perelló (Valencia)
Librería Elías (Asturias)
Donde los libros
Librería Kolima (Madrid)
Librería Proteo (Málaga)
The phase-out of ozone-depleting refrigerants, suchas R-12 and R-22,according to the Montreal Protocol of 1987, hasprovided the incentiveto increase the thermal efficiency of current heating andrefrigeration systems. The purpose of this study wasto increase theaccuracy of the predictions of both theheat transfer and pressure drop correlations forcondensing refrigerants in the Intermittent flowregime. This was doneutilizing a novel method involving the temporal andspectral analysisof the light intensity of the local flow regime, asseen through asight glass. An experimental setup was designed,built and commissionedspecifically for this purpose using refrigerant R-22and a smoothtube. It was found that the accuracy of themean heat transfer coefficient predictions increasedsubstantiallycompared to other leadingcorrelations, particularly at low mass fluxes. Interms of the pressure drop, the predictions alsoincreased inaccuracy, and it was found that the time fractionmethod allows for continuouspredictions over flow regime transitions when usinglocal flow pattern-based pressure drop models.
