Critical heat flux in a multi-minichannel heat sink. Effect of the heated length-on-diameter ratio

34th UIT Heat Transfer Conference 2016

Mastrullo, R.^1 ; Mauro, A.W.^1 ; Viscito, L.^1

Department of Industrial Engineering, Federico II University of Naples, P.le Tecchio 80, Naples

80125, Italy^1

关键词: Diameter ratio;    Experimental values;    Heated lengths;    Mini channels;    R1234yf;    Rectangular ducts;    Reduced pressure;    Saturation temperature;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/796/1/012037/pdf
DOI  :  10.1088/1742-6596/796/1/012037

来源: IOP

【 摘 要 】

This paper exhibits saturated CHF experimental values obtained with R134a and R1234yf, working at saturation temperatures from 25 °C up to 65 °C (i.e. reduced pressures from 0.16, 0.20 and up to 0.46, 0.54, respectively). The mass flux was let to vary from 150 up to 350 kg/m2s. All tests were performed with an aluminum multi-minichannel heat sink, made up of seven rectangular ducts, each of them 2 mm wide, 1 mm high and 35 mm long. Two heated lengths of 25 and 35 mm were structured, in order to study two different Lh/Deqratios. The results show that critical heat flux is enhanced with increasing the mass flux and decreasing the saturation temperature. A greater Lh/Deqratio leads instead to lower CHF values.