冷媒R410Aのアルミニウム製溝付管内の凝縮・蒸発熱伝達および圧力損失

抄録

  This study experimentally investigated heat transfer and pressure drop on condensation and evaporation flows of R410A inside horizontal aluminum microfin tubes at saturation temperatures of 35°C and 10°C for condensation and evaporation flows, respectively. The test microfin tubes had an outer diameter of 8 mm, helix angles of 0 and 20 degree, 36 fins, and fin heights of 0.3 mm. The effects of mass velocity, quality, and helix angle on the heat transfer and pressure drop characteristics for condensation and evaporation flows were investigated. Furthermore, the effect of heat flux on evaporation heat transfer coefficient was also investigated. The measured heat transfer coefficient and pressure drop on the condensation and evaporation flows were compared with the several previous correlations. The correlation of pressure drop for condensation and boiling flows was developed based on present data. The proposed correlation successfully predicted the experimental frictional pressure drop for condensation and boiling flows inside aluminum microfin tubes.