Dynamic simulation, optimal design and control of pin-fin heat sink processes

This paper considers the dynamic simulation, optimal design and direct adaptive control of cylindrical pin-fin heat sink processes. For dynamic heat-dispersion investigation of the pin-fin heat sinks, a 3D model that includes the heat transfer from the heat source to fins and the forced convective heat transfer by a horizontal air-cooling fan is proposed. To optimize the heat dispersion performance, a real-coded genetic algorithm is applied to search for a set of optimal fin-shape parameters and operation conditions. The objective function to be minimized is the entropy generation rate that is able to account for air resistance as well as the heat transfer resistance simultaneously. The comparisons with existing methods show that the obtained optimal design is much better in performance and at the same time is superior in energy savings. Furthermore, to ensure excellent heat dispersion performance when facing environmental and time-varying disturbances, a direct adaptive control system for the temperature regulation of the pin-fin heat sink processes is implemented. The control system is developed using a single-parameter, nonlinear controller along with a parameter-tuning algorithm. A Lyapunov theorem is applied to ensure the stability of the direct adaptive control system. Additionally, extensive simulation results reveal that the proposed direct adaptive control system outperforms conventional on-off and PI controllers, providing a significantly much better heat dispersion performance despite the existence of unexpected environmental variations and disturbances. (C) 2011 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.