A methodology for thermal analysis of complex integrated systems: Application to a micro-CHP plant

Thermal analysis and management studies are commonly conducted from early design stages of new products by numerical means. However, the application of three-dimensional tools for evaluating the thermal performance of multi-component systems, exhibiting high geometrical and phenomenological complexities may become unpractical in view of the long computational times. Therefore, a methodology for thermal analysis of complex thermal systems is developed to improve the overall numerical convergence rate. The methodology is based on an iterative two-way coupling procedure between two sets of simulations: simulation set where critical components are individual and fully simulated (component level simulations); and simulation framework where the overall system is considered with hollow components (system-level simulation). A communication strategy between both simulation sets is established. The methodology can be readily applied for performing thermal management studies. A verification procedure for the suggested methodology is firstly carried out. Afterwards, the methodology is applied to investigate the thermal performance at the system-level of a fuel cell based mu-CHP unit, namely regarding the feasibility of components integration. The methodology application allowed the identification of critical hot-spots (with temperatures up to about 400 degrees C) on the surface of the unit internal components, mainly due to an inadequate insulation thickness and shape. (C) 2016 Elsevier Ltd. All rights reserved.