Experimental study of forced convective boiling for non-azeotropic refrigerant mixtures R-22/R-124 in horizontal smooth tube

2009 ◽  
Vol 29 (8-9) ◽  
pp. 1864-1871 ◽  
Author(s):  
C.B. Chiou ◽  
D.C. Lu ◽  
C.Y. Liao ◽  
Y.Y. Su
Keyword(s):  
Experimental Study ◽  
Smooth Tube ◽  
Convective Boiling ◽  
Refrigerant Mixtures

scholarly journals Heat transfer performance of R1234yf for convective boiling in horizontal micro-fin and smooth tubes

2020 ◽  
Vol 207 ◽  
pp. 01009
Author(s):  
Thanh Nhan Phan ◽  
Van Hung Tran ◽  
Nikola Kaloyanov ◽  
Momchil Vassilev
Keyword(s):  
Heat Transfer ◽  
Flow Pattern ◽  
Mass Flux ◽  
Heat Transfer Performance ◽  
Smooth Tube ◽  
Outer Diameter ◽  
Transfer Performance ◽  
Convective Boiling ◽  
Penalty Factor ◽  
Smooth Tubes

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 a smooth surface and microfin for other. The flow pattern maps were built at 5°C saturation temperature with 8.62 kW/m2 of heat flux, it is presented that flow pattern of helix flow occurs at very low mass flux and low quality, while at that condition on smooth tube the flow is still stratified wavy flow. 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.

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