CRITICAL-REGION MODEL FOR BUBBLE CURVES OF AMMONIA-WATER WITH EXTRAPOLATION TO LOW-PRESSURES

A modified Leung-Griffiths correlation for the near-critical phase bou ndary of ammonia-water is extrapolated to low pressure. The extrapolat ion is based on the observation that, on a plot of logarithm of pressu re vs. inverse temperature, dew and bubble isopleths form straight lin es below the critical region. The extrapolation is performed both dire ctly and with additional optimization to a chosen low-pressure data se t. On the bubble side, the method yields a useful baseline calculation against which different experimental measurements can be tested for m utual consistency, but the approach is considerably less successful on the dew side. Published by Elsevier Science B.V.