Fig. 3 shows that the fluid flow maldistribution is very
serious in the y direction of header for the conventional
header used in industry, so the improvement of header
configuration has become more and more exigent. Based
on the knowledge of the flow distribution obtained
above, a second header configuration with a two-stagedistributing
structure (Fig. 7) is brought forward. The
proposed header is composed of the first and second
header configurations, through which the fluid can be
distributed two times before entering the heat exchanger
core. In order to describe the characteristics of the first
and second header configurations, the equivalent diameter
of the cross-section area and the ratio of equivalent
diameters were introduced here.