Abstract:

Compact heat exchanger surfaces are frequently used in transportation, refrigeration and other industries.The heat transfer coefficient and pressure drop data are essential for design and operation.In this paper a new wavy-perforated plate-and-fin surface is developed and tested by using the single blow technique.A one-dimensional transient heat conduction method is proposed to estimate the effect of non-uniform heat capacity distribution.The calculation shows that the effective mass of bars is very small.The experiments are then performed in the range of Re =350—4000 and the results are compared with those of wavy surface type 11.5-3/8w in literature.It is found that the wavy-perforated heat transfer surface shows 20%-40% higher heat transfer coefficients in the whole test range.For Re <2000,the friction factors of the wavy-perforated surface are lower than or equal to those of the wavy surface in literature.But if Re >2000,a higher pressure drop is necessary for the test unit.So it is concluded that when Re is low, the wavy-perforated surface is a very good choice for compact heat exchangers.