Thermal Model for Temperature Control of Building Subjected to Variable Solar Radiation

摘要

A one-dimensional numerical model is developed to control the room temperature inside the building during summer days. Three layers are considered for the analysis. A layer of phase change material (PCM) is taken between the two layers of concrete for the roof of the building. The rooftop is subjected to variable solar radiation during a summer day which is varying during the sunshine period. Thus, the PCM gets heated and melts by absorbing the heat from the heated roof which helps in controlling the temperature inside the building. Finite Volume Method (FVM) is used to discretise the energy equation. The algebraic equations obtained from discretisation is solved using the Tri-Diagonal Matrix Algorithm (TDMA) to get the temperature distribution across the width of the roof. The solid-liquid interface during melting of PCM is captured using enthalpy-porosity technique. Heat loss by natural convection is taken into account at the roof as well as ceiling. Appreciable reduction in room ceiling temperature is noted by using PCM during the study which is helpful in maintaining the room at comparatively lower temperature on a hot day. This numerical model provides the direction to develop further advanced model to analyse the role of PCM in controlling the temperature inside the room of the building and hence to improve the design of the building for effective human comfort.