Short-time heat impulse intensification of heat transfer in liquid nitrogen.

The cryogenic technology deals with fluids produced from gases after liquefaction. Boiling of cryogenic fluids is frequently characterized by a hysteresis of their boiling curve. The present experimental work demonstrates an opportunity to intensify heat transfer in those fluids by means of short-term heat impulsion from a heater. The intensification takes place due to the impulse-induced transition of heat transfer regime from natural convection towards nucleate boiling. The process takes place when the impulse magnitude overcomes certain minimum value that was quantified experimentally. We also propose a theoretical expression for the minimum energy that is in agreement with the experimental data.