Heat transfer coefficients for the evaporation of ammonia and ammonia-dimethylether-mixture

摘要

The influence of the solubility of oils in ammonia on the heat transfer coefficients for the evaporation have not been examined so far systematically. This paper reports on measurements of these hat transfer coefficients at ammonia and the azeotropic mixture Ammonia-dimethylether with soluble and insoluble oils. The investigations were carried out at smooth tubes and at evaporator tubes with inner fins. It was stated that the influence of the oil solubility is very high and the rise of the heat transfer coefficients is very much larger with finned tubes, than it would be expected due to the inner surface enlargement.