Ammonia is a strong candidate for use as a refrigerant in response to the impending global ban on CFC, and HCFC compounds. There are no heat transfer and fluid flow data available to heat exchanger designers for ammonia in enhanced tubes, or for ammonia with miscible oil. Correlations of the data generated by this research are needed in evaporator modeling and design. The objective of this research project is to investigate basic local two-phase heat transfer and pressure drop during in-tube evaporation of ammonia. The evaporation performance will be quantified for a smooth tube and an enhanced surface micro-fin tube. The study will also investigate the effect miscible lubricants have on evaporation performance. In addition to the experimental study, correlation will be developed that aid in designing evaporators.

Principal Investigator: Don Fenton

Conducted: April 1995 - October 1999

Sponsored by: TC 1.3, Heat Transfer and Fluid Flow