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Evaporation of R407C and R410A in a horizontal herringbone microfin tube: heat transfer and pressure drop

Sven Wellsandt (Institutionen för energi och miljö, Värmeteknik och maskinlära) ; Lennart Vamling (Institutionen för energi och miljö, Värmeteknik och maskinlära)
International Journal of Refrigeration-Revue Internationale Du Froid Vol. 28 (2005), 6, p. 901-911.
[Artikel, refereegranskad vetenskaplig]

An experimental investigation of in-tube evaporation of R410A and R407C has been carried out for a 4 m long herringbone microfin tube with an outer diameter of 9.53 mm. Measured local heat transfer coefficients and pressure losses are reported for evaporation temperatures for R410A and R407C between −2.2 and 9.5 °C and between −5.5 and 13.8 °C, respectively. Mass flow rates between 162 and 366 kg m−2 s−1 have been investigated. Results from this work are compared to R134a data from an earlier work by the present authors, and also to predicted values from some available helical microfin correlations. Compared to R134a data, heat transfer coefficients for the investigated mixtures are generally lower, especially at low mass flow rates. No major effect of heat flux on heat transfer coefficients was found, with the exception of the high quality region. Predicted heat transfer coefficients from helical microfin correlations strongly overpredict the present data. Global pressure losses are predicted well, even though local deviations are found.

Nyckelord: Evaporation, refrigerant mixtures, heat transfer, pressure drop, R407C, R410A, horisontal tube



Denna post skapades 2007-01-07. Senast ändrad 2015-02-11.
CPL Pubid: 24964

 

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Institutioner (Chalmers)

Institutionen för energi och miljö, Värmeteknik och maskinlära (2005-2014)

Ämnesområden

Termisk energiteknik
Kemisk energiteknik
Strömningsmekanik
Molekylära transportprocesser i kemisk processteknik

Chalmers infrastruktur