Parametric analysis of a beta Stirling engine - A prime mover for distributed generation

In this article, a multi-parameter analysis of a beta-Stirling engine has been presented. The calculations have considered the utilization of helium, hydrogen and air as the working media. The analysis was focused on the influence of the frequency (f) and the phase angle ((phi), which were controlled in a wide range of values, on the operational parameters of the device i.e. output power and efficiency. The input parameters (f, phi) were selected as there are mechanical solutions to implement their change in real engines. The possibility of the regulation of the engine might significantly increase its application potential. Precise control and regulation of the engine is of great importance, especially in distributed generation technologies where the ability to operate under partial load is crucial. A mathematical model of the engine was presented and then validated using available data from the literature, including experimental studies for two types of working gas - hydrogen and helium. The maximum output power varied within the range of 2.71-8.8 kW and the efficiency was in the range of 31.7-43.2% depending on the working gas and the controlled parameters: frequency and phase angle.