Validated dynamic energy model for a Stirling engine μ-CHP unit using field trial data from a domestic dwelling

This paper presents the development and validation of a dynamic energy performance model for a WhisperGen Stirling engine micro-CHP (μ-CHP) Mk 4 unit. The model is based on empirical equations for different system characteristics (start-up, continuous operation and shutdown) developed using measured performance data. The model was implemented using MatLab program and its validation was undertaken against measured performance data from a unit installed in a dwelling under field trial in Northern Ireland. Given a heat demand profile for a domestic dwelling, the model can be used to predict the heat and electricity output. Using heat and electricity data for a dwelling over a period of 1 month, the model over-predicted the total electrical and thermal energy output from the μ-CHP unit by 1.4% and 4.2% respectively. The model predicted the electrical power output with a mean absolute error of 7.4% and a cumulative over-prediction of 4.7%. The thermal power output was predicted with a mean absolute error of 7.2% and a cumulative under-prediction of 3.7%.