Analysis of heater-wall temperature distributions during the saturated pool boiling of water

This paper investigates transient temperature fields of thin metal foil heaters recorded with high-speed infra-red thermography during saturated pool boiling of water at atmospheric pressure. Three different thin heaters were tested: stainless steel (SS316), titanium (Ti) and copper with oxidized superhydrophilic surface (CuO). Experimentally acquired temperature fields were analysed using statistical approach. Samples with lower values of wall-temperature standard deviation and skewness and high values of kurtosis are found to perform better during nucleate boiling regime by providing higher heat transfer coefficient. The same samples had narrower heater-wall temperature distributions with higher peaks. The stainless steel sample exhibited bimodal temperature distributions, which resulted from occurrence of bubbles with relatively large contact diameters and long growth times. In addition to that, it was confirmed that wall temperature distributions are effective tool to distinguish between active nucleation sites and non-active single-phase convection area and also to qualify different bubble evolution cycles.