Paper Conference

Proceedings of BauSim Conference 2010: 3rd Conference of IBPSA-Germany and Austria


Dynamische exergetische Analyse von Gebäuden anhand der Gesamtsystemsimulation in der objekt-orientierten Programmiersprache Modelica

Azadeh Badakhshani, Dirk Müller

Abstract: In an exergy analysis not only the system itself but also its surroundings are considered. It is common to determine the exergy demand of a building using a constant reference temperature. However, the mean value of outside temperature as a constant reference temperature can lead to wrong exergy demand estimates because of transient effects in buildings with changing room temperatures (Seifert et al., 2009). In this work a building with a certain exergy demand has been simulated for different cases with different supply and heat delivery systems. Our simulation considers two different supply systems: a normal boiler and a heat pump and two heat delivery systems: a radiator and floor heating. Based on the simulated exergy losses due to transmission and ventilation, the exergy demand of a building can be determined and compared to the transferred exergy of the heat delivery system and installation. The exergy losses in distribution, generation and delivery have been determined and compared with each other. Finally, the exergy demand, and the exergy of generation and distribution have been used to define the characteristic figures of the entire system. This simulation approach can be used as an evaluation measure for exergy efficiency in buildings and their installation. The hydraulic and thermal behaviour of the building is simulated via the object oriented programming language Modelica. The HVAC and building components used in the models were developed in our institute.
Pages: 409 - 413