Boiling of R-134a in horizontal mini tube

Saturated Flow Boiling Heat Transfer in Horizontal Square Tube

ررسی تجربی افت فشار جریان جوششی مبرد R-134a در لوله‌های افقی

The pressure drop of refrigerant R-134a flow boiling inside a horizontal tube has been investigated experimentally. The test set-up which was used in this investigation is a well instrumented vapor compression refrigeration system. These instruments are thermocouples, flow meter, pressure gauges and the pressure drop measuring apparatus. This system consisted of three electrically heated evapor...

Influences of Interfacial Shear in Turbulent Film Boiling on a Horizontal Tube with External Flowing Liquid

The paper presents a theoretical study about turbulent film boiling on a horizontal tube with external flowing liquid. The high velocity flowing liquid is determined by potential flow theory. By using Colburn analogy, the present paper successfully addresses a new model to predict the vaporliquid interfacial shear, applies the interfacial shear into the forced balance equation and then combines...

Flow Boiling Heat Transfer of Binary Mixtures HFO1234yf/R32 in a Smooth Horizontal Tube

HFO1234yf is a promising alternative for automobile air conditioners because of its low GWP of 4 and thermophysical properties similar to those of R134a. However, its performance is inferior to R410A. This makes it difficult to be applied to residential air-conditioners. A mixture of HFO1234yf and R32 is expected to balance both the GWP and COP requirement when applied to residential air-condit...

Water-Heated Pool Boiling of Different Refrigerants on the Outside Surface of a Horizontal Smooth Tube

Pool boiling heat transfer has been extensively studied over decades, but the effect of boundary heating conditions on boiling received little attention. In this work, heat transfer coefficients during pool boiling of five different refrigerants (R123, R245fa, R236fa, R134a, and R22) on the outside surface of a smooth copper tube were measured at the saturation temperature of 6.7 C; water flows...