A comparison of integration solutions for a gas Stirling micro-cogeneration system in residential buildings

Abstract : Micro-Combined Heat and Power (µCHP) is a technology allowing to produce distributed electricity (electrical power below 36 kWel). The main advantage of µCHP is to avoid thermal energy losses while producing and distributing electricity in order to use primary energy rationally. The electricity can be consumed locally in the building or in the neighborhood area while thermal energy can be recovered to satisfy space heating (SH) and domestic hot water (DHW) demands. Stirling Engine (SE) is one of the various µCHP technologies that can be integrated in individual or small multi-family residential buildings. The aim of this paper is to study the impact of storage configurations, hydraulic schemes and control strategies on the performance of a µCHP system. This study is carried out on an individual residential building with various electrical, DHW and SH loads. A dynamic model was developed to represent a 1 kWel gas Stirling µCHP system (producing up to 24 kWth thanks to an auxiliary burner) and has been experimentally calibrated and validated. The model and storage, emitter and distribution network models are implemented in DYMOLA/Modelica environment in order to get a dynamic representation of the whole installation coupled to the building. The comparison between the different cases is shown in terms of primary energy consumption and analysis of operating conditions. The results allow to identify the best SE-µCHP designs according to building conditions.