The performance of highly extended surface heat exchangers has been evaluated in two heat pump applications: as the evaporator in a compression heat pump and as the absorber in an absorption heat transformer. Film heat transfer coefficients based on the equivalent plain tube area (p.t.a.), ranged from 200 W m(-2) K-1, for gas-liquid contact, to 3800 W m(-2) K-1, in the evaporation of a liquid stream. Another measure of the heat transfer characteristics of the exchangers were the 'UA(o)' values, which were significantly better than the theoretical values calculated for each operation. The experimental results ranged from 12 W K-1 (gas) to 214 W K-1 (evaporation), while the theoretical values were 1 W K-1 (gas) and 43 K-1 (evaporation).
|Number of pages||10|
|Journal||Applied Thermal Engineering|
|Publication status||Published - Mar 1996|