ISSN Online: 2377-424X
ISBN Print: 0-89116-559-2
International Heat Transfer Conference 8
HEAT TRANSFER ENHANCEMENT BY DOUBLY AUGMENTED TUBES
要約
The objective of the present paper is to report the heat transfer data taken during the cooling of liquid R-113 inside six double-pipe, counter-flow heat exchangers where R-113 flowed inside the inner tube and the cooling water flowed in the annulus. The inner tubes tested differed in the inside and outside surface conditions. Inner tubes with internal fins on the inside and smooth on the outside, inner tubes with knurls on the outside and smooth on the inside, as well as tubes with internal fins on the inside and knurls on the outside were tested. The overall heat transfer conductances of the different heat exchangers were compared under the same flow rates and same inlet temperatures of both fluids. The conditions under which it is beneficial to use inside or outside surface augmentation alone versus combined inside and outside surface augmentation, were identified. The ratio of R-113 pumping power per unit overall heat transfer rate was used to evaluate the performance of the heat exchangers tested.