INFLUENCE OF AL_2O_3 NANOPARTICLE ADDITIVES ON THE THERMOPHYSICAL PROPERTIES OF AQUEOUS SOLUTION OF PROPYLENE GLYCOL AND ON THE HEAT TRANSFER COEFFICIENT IN FORCED CONVECTION FLOW IN A TUBE

摘要

For the moment, coolants that are composed of aqueous solutions of propylene glycol are widely used in chillers. Such coolants have some advantages over brines or ethylene glycol solutions: non-toxicity, low corrosivity, low crystallization temperature. However, aqueous solutions of the propylene glycol have poor heat transfer efficiency in heat exchangers at low temperatures. One of methods to improve the thermophysical properties of the propylene glycol based coolants and also increasing the heat transfer coefficient in forced convection flow in a tube is an addition of the metal or metal oxides nanoparticles.