| Popis: |
The air cooled automotive condensers under study are of brazed aluminium tube and center, consisting of one row array of horizontal parallel multi-port flat tubes with louver fins on air side. Each tube is with a number of smooth parallel minichannels for internal flow of refrigerant. The analysis uses decomposition of the condenser along refrigerant flow path into specific different zones as follows: two single phase zones, namely: superheated and subcooled, and a few zones of two phase flow that can appear along some specific condensation paths to be: annular/intermittent/bubble or annular/annular-wavy/intermittent/bubble or annular/wavy/stratified. The approach presented is based on experimental correlations for heat transfer and pressure drop. The heat transfer prediction is performed using ε – NTUo methodology. The results of the analysis refer to overall heat transfer rate, heat transfer in particular zones, pressure gradients heat transfer coefficients, vapour quality, condensation paths. |
