Thermal inertia and energy efficiency assessment of Direct Solar Floor system using a switching-linear model

摘要

This study presents a case study of a room equipped with a Direct Solar Floor (DSF) in order to predict the true thermal and energy behaviour. DSF operation during the night by thermal inertia is a complex phenomenon, and its relative impact is proven to be influenced by many factors including the solar radiation and the thermal insulation of the slab. However, current physical models do not show this relationship efficiently. This paper will demonstrate by adopting switching linear models that this relationship can be described formally with a numerical model. In fact, the simulation models developed in literature are represented in a very simplified method and cannot be used for a detailed analysis of thermal operations of DSF. The present study aims to reduce the knowledge gap and resolve the limitations such as (i) a realistic explanation of the thermal behaviour of direct solar floor, (ii) identify the heating mode by thermal inertia in a quick and easy way and (iii) estimate the heating time by thermal inertia for a long period, which can later estimate the gain in energy consumption bring. The switching model has detected three operation modes of the Direct Solar Floor, one of which corresponds to the moment of heating by thermal inertia. The model can also evaluate the duration and the energy provided by the thermal inertia. As a result, it has been estimated at 310 h and 18.6 kWh for a test period of 1110 h, which corresponds to an average of 3.58 h per day.