Component development of the expansion Stirling generator with supercritical fluid as working & lubrication medium

The StirliQ technology has already been researched by 4ward Energy Research together with partners since 2016. The StirliQ engine works neither with a gaseous nor a liquid working medium, but uses a supercritical fluid (CO2).

In the StirliQ preliminary project, laboratory plants were used to demonstrate that the StirliQ engine is superior to conventional Stirling technology - especially in the low-temperature range (< 100°C) - in terms of efficiency. However, the laboratory plants were set up on the basis of a discontinuous process, which proved to be disadvantageous.

The StirliQ+ project is concerned with further development into a continuous cycle. The working medium (CO2) is continuously fed via the heat source and sink and passes through an axial piston machine, which works alternately as a pump and motor. Its flywheel is responsible for transmitting the power to the generator and for maintaining the cycle.

The realization of the StirliQ technology as a CHP plant based on a cyclic process still requires extensive research work. As part of the StirliQ+ project, the cyclic process is being mapped and analyzed in detail using simulation technology, and the technical implementation is being tested using a new laboratory plant.

• Prozess Optimal CAP GmbH
• PK Haustechnik GmbH