Throughout our research and development work, starting in 2001, we have dealt with alpha, beta, and gamma engines and respectively developed and manufactured prototypes. We have taken up the state of the art and implemented several improvements. We developed new concepts and have secured this new ideas with a number of patent applications.
At first, we mostly dealt with trivial issues, for example, manufacturing a sophisticated, completely sealed housing for process gas like helium or hydrogen. We set our focus on the development and production methods of coolers, regenerators, and high temperature heat exchangers, the latter for a temperature range up to 800 degrees Celsius. We have invested considerable resources in this field and the products have proven themselves in the most diverse designs. We can also list outstanding results in the field of dry sleeves between the piston and cylinder liner. After many years of attempts, we have developed durable and extremely tight piston rings, which constitute a new state of the art. We have also developed reliable components in valve technology, for example for pressure control or for the Emergency Stop unit. We also dedicated a longer period of time to generator technology in order to achieve the necessary high efficiencies in asynchronous motors.
The A600 Engine
The research culminates in a first proven engine of the alpha design. This is a ready-to-connect Stirling module with an integrated asynchronous generator, which is directly connected to the three-phase 400-volt mains. The expansion swept volume is nearly 600 ccm, the mechanical output is 5.5 kW, and the electrical output by the six-pole generator at a speed of 1000 RPM is 5 kWel. The process gas, helium, is at moderate 30 bar average process pressure in the entirely enclosed machine. This relatively low process pressure ensures an extremely low load of the moving parts for the benefit of a long service life. The module runs oil-free and therefore can be used in any mounting orientation. Because we learned to adapt the high temperature heat exchangers to the respective requirements of our customers, this results in a number of possible applications. The A600 Stirling module is released for R&D applications.
Heat Exchanger Variations
The series of images shows an overview of already designed high temperature heat exchangers, with which the A600 engine can be equipped. They are adapted to the respective type of heating gas, the dust load, and the emission impact. As an interface to the heating gas, the heat exchangers constitute one of the most stressed components of the engine. The design has a significant impact on the overall efficiency as well as on the service life.