Akademska digitalna zbirka SLovenije - logo
ALL libraries (COBIB.SI union bibliographic/catalogue database)
  • Two-phase heat transfer inside minichannels: experimental measurements of the condensation heat transfer coefficient
    Cavallini, Alberto ...
    This paper presents a new measuring technique for the heat transfer coefficient during condensation inside a 1.4 mm hydraulic diameter multiport minichannel tube. It also reports experimental data ... taken during condensation of R134a. The tube wall temperature is directly measured, so as to obtain the saturation to wall temperature difference and thus the internal heat transfer coefficient in a direct form. The test section presented here is made of threecounter-f1ow heat exchangers. It is realized with one 1.8 m long mu1tiport tube and three separated jackets. The refrigerant condenses in the minichannels against the cooling water flowing in the jackets. The actual measuring sector is the third heat exchanger, considering the refrigerant flowdirection. The other two heat exchangers are only used to achieve the desired value ofvapor quality. The test section has been designed with the purpose of achieving bot~ high water-side heat transfer coefficients and good mixing of the cooling water during tests. The final design is the result of the Finite Volume Method modeling and prototype testing. The tests showed thatthe measured heat transfer coefficient does not depend on the water side coefficient.
    Type of material - conference contribution
    Publish date - 2004
    Language - english
    COBISS.SI-ID - 29128709