کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
788661 | 1466415 | 2015 | 12 صفحه PDF | دانلود رایگان |

• Shell and micro-fin tube evaporator model using R1234yf and R134a is presented.
• Several two-phase flow heat transfer correlations for micro-fin tube are used.
• The predicted and experimental data are compared in order to study the accuracy of the model.
• The model using Akhavan–Behabadi correlation obtains the best predictions.
• R1234yf's overall HTC is up to 10% lower compared to R134a.
This paper presents a model of shell and tube evaporator with micro-fin tubes using R1234yf and R134a. The model developed for this evaporator uses the ε-NTU method to predict the evaporating pressure, the refrigerant outlet enthalpy and the outlet temperature of the secondary fluid. The model accuracy is evaluated using different two-phase flow boiling correlations for micro-fin tubes and comparing predicted and experimental data. The experimental tests were carried out for a wide range of operating conditions using R134a and R1234yf as working fluids. The predicted parameter with maximum deviations, between the predicted and experimental data, is the evaporating pressure. The correlation of Akhavan– Behabadi et al. was used to predict flow boiling heat transfer, with an error on cooling capacity prediction below 5%. Simulations, carried out with this validated model, show that the overall heat transfer coefficient of R1234yf has a maximum decrease of 10% compared with R134a.
Journal: International Journal of Refrigeration - Volume 50, February 2015, Pages 32–43