Overview and discussion on pool boiling heat transfer data and correlations of ammonia

An overview on the heat transfer behaviour of boiling ammonia (R 717) under pool boiling conditions will be given. The influence of surface geometry (smooth, microfin, coated) and oil will be discussed. Experimental results and prediction methods will be presented. In addition to the open English literature, experimental data on pool boiling heat transfer of ammonia published in former German and Russian papers will be analyzed.The experimental pool boiling data investigated cover the following range: ϑs = −40 to +38.7 °C, ps = 0.72 to 15 bar (pr = 0.006–0.13), q = 0.44–2500 kW/m2. Different heater materials have been used: carbon steel, stainless steel, platinum, silver, copper. The experimental data are compared with correlations e.g. by Stephan/Abdelsalam, Stephan/Preuβer, Mostinski, Cooper and Gorenflo. Porous structures and spray evaporation yield enhancement in pool boiling heat transfer. The oil diminishes the heat transfer coefficient strongly.