Study of thermal conditions on wall of a pipe during removal of heat by water at a supercritical pressure

The results of an experimental investigation into the thermal conditions existing on the wall of a pipe $10.4$ mm in diameter with a heated length of $500$ to $750$ mm during the removal of heat by water at a pressure of $245$ bars are presented. Measurements are carried out over a period of time during the transition from normal to subnormal conditions of heat transfer and vice versa. Cases are found in which there is a spontaneous rise in wall temperature with time, although the operating conditions remain constant.