HEAT-TRANSFER IN BUBBLE LAYERS AT HIGH-PRESSURES

We have performed the first experimental investigation of heat transfe r accompanying condensation of water vapor on the surface of a cooled horizontal pipe in a bubble layer. The experiments were conducted at p ressures of 0.72-3.8 MPa, volume vapor content of 0-0.18, reduced vapo r velocities of 0-0.085 m/sec, and liquid-wall temperature drops of 38 -106 K. It is shown that the well-known computational relations, propo sed for the case of bubbling of air at atmospheric pressure, systemati cally underestimate the heat emission. In the course of this work we a lso obtained data on heat transfer with film condensation of saturated vapor and natural convection of underheated water under conditions of large temperature heads, outside the previously studied range.