|Autors: Phan, T. N., Tran, V. H., Kaloyanov, N. G., Vassilev, M. P.|
Title: Heat transfer performance of R1234yf for convective boiling in horizontal micro-fin and smooth tubes
Keywords: R1234yf, convective boiling, micro-fin tubes, smooth tubes
Abstract: This study analyses the performance of heat transfer process which occurs in the convective boiling of Hydro fluoro Olefin (HFO) refrigerant, R1234yf, in horizontal tube. Heat transfer and pressure drop of R1234yf are analyzed and computed at the same working conditions on the same size of outer diameter of tube do = 9.52 mm with difference of inner surface, one is а smooth surface and microfin for other. The comparison of heat transfer performance between microfin and smooth tube would be evaluated on enhancement factor E, penalty factor P and efficiency index I. With the mass flux on the range G = 111 ÷ 333 kg/m2s for 5°C boiling temperature, the results show that, average value of E is 2.18; 1.45 of P and 1.54 of I. One more impressing thing is that, at the quality “x” larger than 0.8, the dryout phenomenon takes place on smooth tubes while microfin tubes do not have this phenomenon.
Вид: публикация в национален форум с межд. уч., индексирана в Scopus и Web of Science