Comparative Study of the Cooling of a Hot Temperature Surface Using Sprays and Liquid Jet

International audienceAn experimental test-rig was designed to study the cooling of hot surfaces under semi-industrials conditions. Two cooling methods were compared: liquid jet and full cone sprays. The wall is a 175 mm diameter nickel disk heated by electromagnetic induction up to 800 °C. The heat removed during the cooling phase was investigated with the use of infrared thermography while the droplet properties, in the case of sprays, were characterized simultaneously with a Phase Doppler system. In the case of spray cooling, the Phase Doppler technique was mainly applied to study the statiscal properties of the droplets in the vicinity of the heated surface. The influence of the liquid mass flux distribution as well as the droplets properties on the cooling are studied by using five different spray nozzles. The liquid mass flux distribution is also measured with the help of patternator. The main results show that even if higher heat flux can be removed with the liquid jet the efficiency cooling is poor because of its non uniformity. When spray cooling is considered, the results are in qualitative agreement with previous studies performed in similar conditions