Inverse method to estimate air flow rate during free cooling using PCM-air heat exchanger

Free cooling technique using Phase Change Material (PCM) is a promising process to shave the peak load for the cooling system and reduce energy ventilation consumption. However it needs additional energy for the fan. In the way optimize the process we then proposed a first approach to estimate a priori the flow rate required to reach full freezing or thawing of PCM which is a useful indication of the process efficiency. The approach is based on the inverse method associated with sensitivity coefficient. The objective function was defined in terms of air temperature at the exit of the heat exchanger. The model was compared to experimental data, and the validation of numerical results shows the robustness and the consistency of this method. In the worst case, relative error does not exceed 5 × 10−03.