Falling film evaporation heat transfer performance of R404A outside horizontal Y-type fin tubes

In order to explore the falling film evaporation heat transfer performance of R404A outside the enhanced horizontal Y-type fin tube, carries out the falling film evaporation experiment, under the experimental conditions of the spray density Γ=0.039~0.056 kg/(m·s), evaporation temperature t=5~20 ℃, and heat flux density q=15~35 kW/m2. Applies the thermal resistance separation method and the modified Wilson-Gnielinski graphic method to process the experimental data to obtain the heat transfer coefficient outside the tube, and investigates the influence of various parameters on the heat transfer performance. According to the experimental results, designs the orthogonal test. The results indicate that the heat flux density has the greatest influence on the heat transfer coefficient of the falling film of the tube, followed by the spray density and the evaporation temperature. Under the condition of Γ=0.046 5 kg/(m·s), t=20 ℃, q=20 kW/m2, the corresponding falling film evaporation heat transfer coefficient is the highest. Uses the dimensionless analysis and multivariate nonlinear regression methods to fit the falling film evaporation heat transfer correlation equation of the tube.