BOILING HEAT TRANSFER IN SWIRL FLOW OF SUBCOOLED WATER AT ONE-SIDE HEATING

摘要

The paper presents the results of experimental studies of heat transfer in subcooled water flow boiling at one-side heating. The experiments have been performed in the following range of the parameters: mass flux G velence 340 / 11 000 kg/(m~(2)s), pressure p velence 1.0 and 2.0 MPa, water temperature at the inlet T_(f) velence 20/60 deg C, twist ratio y velence 1.75, 2.38, 4.0, 6.38, infinity (straight tape). At the present work the new method of determination of wall temperature and heat flux on the inner and external wall of the test-section is used. The method is based on direct temperature measurements in a body of the test-section. It was obtained more than 300 points on local heat transfer coefficient at subcooled water swirl flow boiling. An analysis of swirl flow rate effect on heat transfer is made. The boundaries of transition from single-phase convection to boiling are detected. It's shown that at a high mass flux and subcooling boiling starts at the heat flux more than 15 MW/m~(2). The method of boiling heat transfer calculation is developed.