Condensation-induced water hammer in a horizontal pipe

Experiments were conducted for the purpose of investigating the phenomenon of condensation-induced waterhammer in an ammonia refrigeration system. Waterhammer was initiated by introducing hot ammonia gas over static subcooled ammonia liquid placed in a horizontal 146.3 mm diameter carbon steel pipe approximately 6.0 m long. By means of fast response piezoelectric pressure transducers and a high speed data acquisition system rapid dynamic pressures were recorded whenever a condensation-induced event occurred. Moreover, by means of top-mounted diaphragm pressure transducers sensing gas pressure the speed of liquid slugs propagating along the pipe was determined. Based upon careful interpretation of the results criteria for the transition from initial stratified flow to slug flow were established, similar to the so-called Taitel-Dukler correlation in two-phase flow literature.