An exergy-based multi-objective optimisation model for energy retrofit strategies in non-domestic buildings

Abstract

While the building sector has a significant thermodynamic improvement potential, exergy analysis has been shown to provide new insight for the optimisation of building energy systems. This paper presents an exergy-based multi-objective optimisation tool that aims to assess the impact of a diverse range of retrofit measures with a focus on non-domestic buildings. EnergyPlus was used as a dynamic calculation engine for first law analysis, while a Python add-on was developed to link dynamic exergy analysis and a Genetic Algorithm optimisation process with the aforementioned software. Two UK archetype case studies (an office and a primary school) were used to test the feasibility of the proposed framework. Different measures combinations based on retrofitting the envelope insulation levels and the application of different HVAC configurations were assessed. The objective functions in this study are annual energy use, occupants' thermal comfort, and total building exergy destructions. A large range of optimal solutions was achieved highlighting the framework capabilities. The model achieved improvements of 53% in annual energy use, 51% of exergy destructions and 66% of thermal comfort for the school building, and 50%, 33%, and 80% for the office building. This approach can be extended by using exergoeconomic optimisation.

Thermodynamic and exergoeconomic analysis of a non-domestic Passivhaus retrofit

“…The modelling tool has embedded a comprehensive techno-economic retrofit database, which will be used to assess the economic characteristics of the Passivhaus design. Equations for dynamic exergy analysis and exergoeconomic analysis method have been outlined previously [38,39].…”

“…Thermodynamic assessments typically require an input-output abstraction of all the subsystems interacting in an energy system. To appropriately define exergy streams of buildings and their energy systems, a thermodynamic abstraction of the whole building system should be made [38]. Fig.…”

An exergoeconomic-based parametric study to examine the effects of active and passive energy retrofit strategies for buildings

“…The sources for the archetype development as well as main characteristics have been presented in previous research [37]. The buildings were assumed to be built before first building energy regulations were implemented prior to 1965.…”

“…For this purpose, the expansion of EXRETOpt [37] (a recently developed retrofit-oriented exergy-based dynamic simulation tool) is necessary through the integration of an exergoeconomic analysis module.…”

“…EXRETOpt is a retrofit-oriented exergy-based tool based on EnergyPlus [38], the details of which are discussed in a previous publication by the authors [37]. For this study, a pythonbased model was developed to perform exergoeconomic calculations within it.…”