Enhancement of Nucleate Pool Boiling Heat Transfer in Ammonia/Water Mixtures (Effect of Surface - Active Agent) (2nd Report)

摘要

The boiling curves of ammonia/water mixtures have been measured when a surface-active agent was added into the mixtures. The effect of the concentration of ammonia and the surface-active agent on boiling was experimentally clarified. The experiment has been carried out to enhance the boiling heat transfer coefficients of ammonia/water mixtures on a horizontal heated fine wire at pressure of 0.4 MPa by adding the surface-active agent into the mixtures. As a result, the coefficients were enhanced in lower ammonia mass fraction (C≦0.5) and low heat flux range which is just after onset of boiling. It was also found that the enhancement effect by the surfactant disappears in surfactant concentration over 1000 ppm.