Experimental Flow Boiling Study of R245a at High Reduced Pressures in a Large Diameter Horizontal Tube
نویسندگان
چکیده
Evaporators used in organic Rankine cycles (ORC) are designed using existing flow boiling correlations that mainly based on HVAC&R data. However, the ORC evaporators employed industry typically have larger diameters and operational conditions at higher reduced pressures compared to applications. The present study presents results of heat transfer experiments representative for an industrial waste recovery low-temperature ORC’s evaporator tube, by being performed high a large-diameter horizontal tube with R245fa as working fluid. measurements within range mass flux, saturation temperature flux 83–283 kg/m2s, 85–120 °C (8.9–19.2 bar) 17–29 kW/m2, respectively. Test section is round plain carbon steel 21 mm I.D., 2.5 m length. 513 local two-phase coefficients recorded. experimental each other reveal coefficient trends respect varying conditions. Four distinctive zones observed, namely, nucleate dominant (NBD) zone, weakening dominance (WNBD) zone (FBZ) dry-out (DOZ). Heat vs vapor quality partly resembled CO2 reported literature. Two moderately predicted
منابع مشابه
Experimental Study on the Effect of Magnetic Field on Critical Heat Flux of Ferrofluid Flow Boiling in a Vertical Tube
In the present work, the critical heat flux measurements were performed for the subcooled flow boiling of pure water and magnetic nanofluids (i.e., water + 0.01 and 0.1 vol.% Fe3O4) in a vertical tube. The effect of applying an external magnetic field on the CHF variation was studied experimentally as well. The obtained results indicated that the subcooled flow boiling CHF in the vertical tub...
متن کاملThe 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...
متن کاملeffect of sub-grid scales on large eddy simulation of particle deposition in a turbulent channel flow
چکیده ندارد.
15 صفحه اولFlow 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...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Energies
سال: 2022
ISSN: ['1996-1073']
DOI: https://doi.org/10.3390/en15030864