Convective boiling of R-134a on enhanced-tube bundles

New High Efficiency R-134a Compressor

Over the last thirty years, few changes have taken place in reciprocating refrigeration and freezer hermetic· compressors. Of course there have been design improvements and many new applications, but the basics have stayed the same. DOE requirements have brought new energy standards for 1993 and, with most of that work behind them, manufacturers of white goods are concentrating on alternate ref...

Flow Patterns During Convective Boiling in Microchannels

Convective heat transfer in foams under laminar flow in pipes and tube bundles.

The present study reports experimental data and scaling analysis for forced convection of foams and microfoams in laminar flow in circular and rectangular tubes as well as in tube bundles. Foams and microfoams are pseudoplastic (shear thinning) two-phase fluids consisting of tightly packed bubbles with diameters ranging from tens of microns to a few millimeters. They have found applications in ...

The Effect of Linear Change of Tube Diameter on Subcooled Flow Boiling and Critical Heat Flux

One of the major industry problems is the flow boiling, where reaching to the critical heat flux (CHF) condition can lead to a temperature jump and damage of the systems. In the present study, the effects of a uniform change in tube diameter on subcooled flow boiling and CHF was numerically investigated. The Euler-Euler model was used to investigate the relationship between the two liquid and v...

Characterization of R-134a superheated droplet detector for neutron detection.

R-134a (C2H2F4) is a low cost, easily available and chlorine free refrigerant, which in its superheated state can be used as an efficient neutron detector. Due to its high solubility in water the R-134a based superheated droplet detectors (SDD) are usually very unstable unless the detector is fabricated using a suitable additive, which stabilizes the detector. The SDD is known to have superheat...