On Thursday, December 20, 2018, Patricia CARBAJO JIMENEZ, a doctoral student in engineering sciences at the Laboratoire d'Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), will submit her thesis "Optimization methodology for a new water-air hybrid solar thermal system concept".
The defense will take place at 10 am, in the Hélios building, room INES academics, in Le Bourget-du-Lac.
Summary of the thesis
In response to changing thermal regulations, buildings are tending to be better insulated and more airtight, reducing their heating requirements. Ventilation, necessary to guarantee indoor air quality, represents a significant energy loss. What's more, domestic hot water (DHW) requirements are becoming more important than heating needs. In this context, solar thermal systems can provide a significant proportion of a building's heating requirements. This study examines a solar water heater for DHW production and ventilation air preheating. This innovative hybrid operation enables solar thermal systems to adapt to the new distribution of energy demand in high-performance buildings.
The aim of this thesis is to develop a methodology for optimizing the management of solar heat, distributed between the energy vectors water and air, with the aim of maximizing the potential of recovered solar energy and, consequently, reducing the use of other energy sources in the building. Firstly, the concept of the hybrid solar system studied was validated and its limitations identified experimentally on a test house. A numerical model of the system was then implemented in the Dymola environment, using the Modelica language, and compared with the experimental data. The interaction of the system with the building requires the coupling of the system model with the EnergyPlus building model, using co-simulation. Numerical simulations thus enable us to analyze the behavior of the hybrid solar system and find a solar heat distribution mechanism suitable for high-performance buildings. With the ultimate aim of minimizing energy consumption, the variables with the greatest influence on the hybrid system's performance were identified using a sensitivity analysis, with the decision variables selected participating in a multi-criteria cost-energy consumption optimization. This work thus proposes a methodology for the optimized management of heat recovered by a solar water-air hybrid system. The integration of indoor air quality and thermal comfort indicators in future work could complete this methodology.