Research Project Summary Information
5kWe free-piston Stirling engine(ST10344-1)
When using the gas generated on-site for electricity generation, landfills typically use diesel or internal combustion engines that often require mixing of the biogas with propane or natural gas in order to achieve a fuel quality level that is appropriate for the engines to run. More recently, microturbines have been used in these landfill gas applications, though both these engines and the ones historically used have significant wear and maintenance issues associated with them.
To address this, the Contractor, Foster-Miller, Inc., has designed a 5kWe free-piston Stirling engine that has no mechanical seals and uses external combustion, whereby significantly reducing the required maintenance on the system. The engine has only two moving parts that oscillate in a sealed housing when the engine is supplied with heat, producing AC power. These features make the Contractor’s free-piston Stirling engine an excellent candidate to burn dirty fuels such as landfill off- gases, sewage digester off- gases, and industrial waste gases.
The goal of this 12 month project is to build and test a prototype free-piston Stirling power system suitable for use with digester or landfill gases. The technical goal for this unit is to obtain 5 kW of single phase AC power with 25% overall thermal efficiency.
Tasks involved in this effort include component procurement, system assembly, performance testing and analysis, and a comprehensive market assessment.
Potential benefits of this technology include realization of a portion of the two Billion kWh potential of landfill gas in NYS, reduced contribution of landfill gas to smog and global warming, and the growth of new technical jobs in NY.
Work on procurement and assembly of the engine was completed satisfactorily and the required test facility preparation was completed successfully. However, the multi-step processes required to fabricate the engine’s hot end assembly proved challenging and, in the end, engine performance during testing fell well below expectations.
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R&D -Transport & Power Systems