The threshold value of heat flux for thermosyphon microfilm heat transfer with the testing sample partially immersed in liquid nitrogen

Abstract To simulate the performance of condenser-boiler in an air separation plant, the boiling section formed by 1m long plate-fin narrow channel is only partially immersed in liquid nitrogen. When the heating power supplied to whole section of the testing sample is maintained constant the boiling temperature difference is increased by 0.19K only with reduction in immersion depth of 40cm. It is concluded that the condenser-boiler will be operated in a safe condition even when the immersion reduced by 40% as long as the heat flux is maintained above a threshold value.