Development of a low-temperature Stirling cycle engine for an autonomous solar cogeneration plant
摘要
This article presents the design and development of a low-temperature Stirling engine with external heat supply intended for use in autonomous cogeneration power systems. The engine utilizes thermal energy from a solar collector, which heats the working fluid to temperatures ranging from 90 to 100 °C. A key innovation of the proposed system lies in the significantly increased swept volume of the displacer, which exceeds the volume of the power piston by a factor of 20 to 40. This configuration enables stable engine operation under relatively low temperature differentials between the heater and the cooler. Experimental investigations, supported by results of numerical modeling, confirmed the feasibility and efficiency of the proposed design. Under operating conditions with a temperature differential of approximately 65–75 °C and a working fluid pressure of up to 0.3 MPa, the engine demonstrated a mechanical output ranging from 5 to 15 W, with a corresponding thermal efficiency of 2 to 4%. Notable performance improvements were observed when air was replaced by helium as the working medium and a regenerator was incorporated into the system. The cogeneration capability of the system is realized through the recovery and utilization of residual heat from the cooling circuit for space heating and domestic hot water supply. The engine is designed for fully autonomous operation in remote or off-grid areas, including rural settlements, greenhouse complexes, and other energy-demanding infrastructures. When integrated with a solar collector and thermal energy storage unit, the system offers the potential for continuous, around-the-clock electricity and heat generation.