Conceptual development of constructal theory towards optimum sizing of radiant enclosures

摘要

This paper focuses on a simple method towards optimal sizing of radiant enclosures through thermal resistance analysis and the concept of constructal theory. In this method, a new approach based on constructal theory is presented to optimize the aspect ratio of rectangular radiant enclosures by the aim of maximizing the heat flux on the product surface. Based on constructal theory, the global radiation resistance between all surfaces is minimized by adjusting the aspect ratio of the shape while the volume of the enclosure is fixed. The problem is solved by using a Genetic Algorithm (GA) for delivering the optimal aspect ratio. The performance of the present method is evaluated by solving the problem numerically for a soaking zone in a reheating furnace which is separated from the adjacent zone by a zone divider. It is shown that the maximum of heat flux will occur when the heat transfer area of the zone approaches the square area. Moreover, the optimum size of the soaking zone for various scenarios in terms of retrofit is investigated.