Wall Temperature fluctuation and self-compensation effect of two phase flow in new condenser-boiler in liquid nitrogen

摘要

A prototype plate-fin condenser-boiler section was constructed with a central condensing channel and two outside boiling channels. Liquid nitrogen is evaporated inside the boiling channel at atmospheric pressure due to electric heating at outside walls of boiling channel. The wall temperature fluctuations were measured with the testing sample in different depth of submerge. At heat flux less than 7000w/m~2, the amplitude of the fluctuation is less than 0.3K. The total temperature difference for heat transfer is only 0.45K at heat flux of 10 kW/m~2. It means that there is a sound self-compensation effect in thermosyphon two phase flow in liquid nitrogen. The effect makes the condenser-boiler in air separation plant operate in a safe condition.