NANOFLUIDS APPLYING FOR EMERGENCY COOLING OF HIGH LOADED EQUIPMENT

Abstract

Based on these data and a brief literature review we have examined the principled possibility of using nanofluids for emergency cooling of high-energy equipment. With that end in view, the possibility of emergency cooling of an overheated heat transfer surface using nanofluids in the case of a boiling crisis is explored by means of synchronous recording of changes of main heat transfer parameters of boiling water over time. Two nanofluids are tested, which are derived from a mixture of natural aluminosilicates (AlSi-7) and titanium dioxide (NF-8). It is found that the introduction of a small portions of nanofluid into a boiling coolant (distilled water) in a state of film boiling (theater > 500 °C) can dramatically decrease the heat transfer surface temperature to 130–150 °C, which corresponds to a transition to a safe nucleate boiling regime without affecting the specific heat flux. The fact that this regime is kept for a long time at a specific heat load exceeding the critical heat flux for water and theater = 125–130 °C is particularly important. This makes it possible to prevent a potential accident emergency (heater burnout and failure of the heat exchanger) and to ensure the smooth operation of the equipment. It is shown that cooling of energyloaded equipment by using aluminosilicate NFs is quite realistic and cost-effective process. Bibl. 22, Fig. 4, Tab. 1.