The purpose of a heat exchanger header box is to act as a high pressure manifold that redistributes process fluid from a central source to a bundle of finned tubes where it can be cooled. Due to the lack of certified cover type header box design codes, industrial manufactures are left to develop their own in-house codes. This paper presents an investigation of an in-house design code and compares its results with those from finite element analyses. After analysing multiple sample designs, it was found that header boxes designed using this method were all over-designed. To address this problem, a new 2D finite element software package was developed, based on an open source platform, and validated to accurately analyse cover type header boxes. The software can be used to validate any existing designs, as well as to provide an optimal design and accurate stress predictions for new header boxes, thus reducing uncertainty in the design process.
The focus of this research is to investigate and improve the methods used to design cover type header boxes for aircooled heat exchangers. An air-cooled heat exchanger is a device that rejects heat from a process fluid directly to ambient air. By construction, it is a vessel that removes heat
from a process fluid by forcing cool ambient air over a collection of finned tubes through which Hot process fluid is pumped into an inlet
header box, which channels the fluid into the finned tubes. Here the fluid flows through the tubes and into an outlet header box before exiting through an outlet nozzle. Simultaneously, cool air is blown over the finned tube bundle by a fan to accelerate the exchange of heat between the air
and the fluid in the tubes.