Development of a 3 kW Microturbine for CHP Applications

Combined heat and power (CHP) concepts for small-scale distributed power generation offer significant potential for saving energy and reducing $CO2$ emissions. Microturbines are an interesting candidate for small CHP systems with advantages in terms of performance, size, noise, and costs. MTT is developing a 3 kW recuperated microturbine for micro CHP applications for large households and for truck combined APU-heating systems. To minimize costs, off-the-shelf automotive turbocharger technology has been used for the turbomachinery. During recent years, turbocharger turbomachinery performance and efficiencies have significantly increased, even for very small sizes. At the same time, efficient high-speed motor-generators have become available at relatively low prices. The development of a concept demonstrator started in May 2008. This program phase included a cycle analysis and component selection study around off-the-shelf turbomachinery, design of a custom combustor, recuperator and generator, and a test program. In this paper, results of the cycle definition, conceptual design and component matching study are presented. Next, the development of a detailed performance model is described and performance prediction results are given. Also, results of the test program and test analysis work are presented. Finally, from the conclusion of the demonstrator phase an outlook is given on the prototype design and performance, which will be the next phase of the development program.