The effect of pressure on burnout in a round tube cooled by FREON-12

Abstract

A resistance heated, uniform wall thickness, stainless steel tube (16 mm i.d. x 2,860 mm long) with an upflow of Freon-12 (dichlorodifluoro-methane), subcooled at the inlet, was used to obtain data of the effect of pressure on burnout heat flux. Values of reduced pressure (ratio of system pressure to the critical pressure of the fluid) at inlet to the test section were in the range 0.2 - 0.4, with mass velocity ranging 0.8 - 4.1 Mg m-2s-1. Data are adequately described by an existing correlation, except at the lowest test pressure (reduced pressure of 0.215) where the experimental values of burnout heat flux were up to 40 per cent higher.