Development of a Generic and Simplified Mathematical Model of a Building Space in MATLAB/ Simulink

Authors:

VSKV Harish (Indian Institute of Technology Roorkee, Roorkee)

Arun Kumar (Indian Institute of Technology Roorkee, Roorkee)

Abstract:

MATLAB/Simulink has been widely used for modeling and implementation of advanced control techniques for heating, ventilation and air conditioning (hvac) systems and building spaces. A mathematical thermal model of a building space has been developed in MATLAB/ Simulink. Building space under study is influenced by the hvac systems and occupancy schedules are also incorporated into the model to add practical cases. A simple mathematical equation has been formulated for the building space under study using the energy conservation principle. A first order differential equation depicting the net heat gain in the building space has been modeled in simulink. The building model is fed with climate data (Outdoor temperature profile), hvac plant and internal gains. Ventilation component of hvac system has been modeled using a time schedule technique and a look up table block available in Simulink is used for interpolating number of air changes per hour according to the room’s indoor temperature. Internal gain block has been used for time scheduled ventilation. Heater subsystem has a set point block with the desired room temperature and the corrected control signal is then fed to the saturation block to limit the control signal within the specified value. Developed model has been simulated for outdoor temperature climate data and as per the desired set point temperature variations in the indoor room temperature and costs incurred by operating the hvac system has been obtained.

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