An Experimental Data-Driven Model of a Micro-Cogeneration Installation for Time-Domain Simulation and System Analysis

Abstract

In this article, an investigation of a free-piston Stirling engine-based micro-cogeneration (μCHP) unit is presented. This work is a step towards making the system calculations more reliable, based on a data-driven model, which enables the time-domain simulation of the μCHP behavior. A laboratory setup was developed that allowed for the measurement of a micro-cogeneration unit during long-term operation with a variable thermal load. The maximum efficiency of electricity generation was equal to 13.2% and the highest overall efficiency was equal to 95.7%. A model of the analyzed μCHP system was developed and validated. The simulation model was based on the device’s characteristics that were obtained from the measurements; it enables time-domain calculations, taking into account the different operating modes of the device. The validation of the system showed satisfactory compliance of the model with the measurements: for the period modeled of 24 h, the error in the heat generation fluctuated in the range 0.31–4.50%, the error in the electricity generation was in the range 2.48–4.70%, the error in the natural gas consumption was in the range 0.26–4.59%, and the engine’s runtime error was in the range 0.14–8.58%. The modelling process is easily applicable to other energy systems for detailed analysis.

Exergy and Exergy-Economic Approach to Evaluate Hybrid Renewable Energy Systems in Buildings

“…The model was validated by experimental results and built into the TRNSYS environment. Uchman et al [19] studied a gas-fired free-piston Stirling engine coupled with thermal storage and built up a data-driven model based on the experimental measurements. González-Pino et al [20] investigated gas-fired Stirling micro-cogeneration as well.…”

Experimental and Numerical Study of a Microcogeneration Stirling Unit under On–Off Cycling Operation

“…Micro-cogeneration Stirling units are a viable option for small-scale residential and commercial applications because of their high total efficiencies, favorable ratios of thermalto-electric power with respect to the loads they must meet, low CO as well as NOx emissions, extended time between maintenances, and reduced vibrations during operation [1,2]. In contrast to the case of large industrial applications where both thermal and electric loads are relatively constant throughout the year, residential and commercial applications are characterized by large fluctuations of electricity, heating, and cooling loads, which are strictly related to climatic conditions and to the end-users' needs.…”

Comparative Study of Electric Machines for Stirling Generator Application

“…Many authors develop some models to increase the efficiency of Stirling generators for different applications. These include cogeneration [2][3][4][5][6], the conversion of exhaust gas heat into electricity [7][8][9], the recovery of biomass [10][11][12][13], the conversion of solar energy into electricity [14][15][16][17], the dual use of heat for cooking and lighting [18]. In references [19] and [20], since the output frequency of the Stirling engine is low, authors develop a model to improve the performance of the regenerator and the hot head of the heat engine to increase the final speed.…”