Development of a Micro-Hybrid Gas/ORC Turbine

MiHyT

This project aims to develop and demonstrate an advantageous and innovative alternative to combined heat and power (CHP) plants: the combustion of gases in a micro gas turbine (mGT) and the use of the high exhaust gas temperatures in a following organic Rankine cycle (ORC). The efficiency can match that of a CHP and offers decisive advantages of the mGT over conventional combustion. These are primarily very low-emission combustion (especially NOx) and high fuel flexibility. A central component and, at the same time, a challenge in such a combination are high-temperature -resistant ceramic heat exchangers and other components that are being developed in the project. Two system variants are being built and tested in the project. A new feature is the combination of mGT and ORC on a common drive shaft to form a micro hybrid turbine (“MiHyT”) with a ceramic coaxial heat exchanger. Various manufacturing options and designs are being tested and compared in the development of the ceramic heat exchangers and turbine components. As an alternative to the use of gas combustion, the economic feasibility of “solar firing” of the mGT using solar tower technology is being investigated. Further applications of the technologies developed are being evaluated in the project.

In particular for larger power classes, it is also possible to decouple mGT and ORC and operate them in parallel, for which an ORC system with a turbine for utilizing temperatures up to 200-300°C based on a commercial ORC unit is being developed.

3D-Entwurf einer möglichen Lösung für die integrierte Mikrohybridturbine »MiHyT« mit Gasturbine und ORC-Turbine auf einer Welle.
© h_da
3D concept of a possible implementation of the integrated micro hybid turbine “MiHyT” including a micro-gasturbine and an ORC-turbine on one shaft.

Initial Situation

Small and medium-sized CHP units are widely used to convert gases into electricity and heat, for example for residual gas combustion in the Chemical Industry, for synthesis gases or for biogenic gases. In these units, a classic combustion engine driving a power generator is ideally combined with the use of waste heat. The innovative micro hybrid turbine can replace classic CHP units and promises lower-emission combustion and greater fuel flexibility with comparable efficiency for the provision of electricity and heat. 

The project partner Orcan Energy is currently building ORC units up to 100 kWel for the conversion of waste heat up to approx. 130°C into electricity. For larger power classes up to the MW range and higher waste heat temperatures, not only upscaling is required, but also a technology change from screw expanders to turbines, which is being developed, prototyped, and tested in the project. In addition, the use of higher temperatures also allows for the operation as combined heat and power generation unit due to the higher waste heat temperatures.

100 kWel-ORC-Aggregat der Firma Orcan Energy AG, auf das aufbauend das neue System der MWel-Leistungsklasse entwickelt wird.
© Orcan Energy AG
100kWel-ORC-Aggregate of Orcan Energy AG, based on which the new system in the MWel power range will be developed.

Objective

The overall objective of the joint research project is to develop an innovative combination of a micro gas turbine (mGT) and an organic Rankine cycle (ORC) in a micro hybrid turbine “MiHyT” using novel ceramic parts for recuperators and turbine components for efficient and low-emission combustion, e.g., of residual gases in the Chemical Industry, and the construction of prototypes of a “MiHyT” in the power class up to approx. 80 kWel, as well as of an ORC unit for waste heat utilization at 200-300°C in the MW power class.

The objectives of the Fraunhofer ISE subproject are to coordinate the joint research project, test the ORC unit in the MW power class, develop and optimize a “coaxial” heat exchanger, evaluate heat exchangers in simulation, construct and test model systems made of plastic, and evaluate the possibilities of using 3D printing of ceramics to manufacture the heat exchanger. Fraunhofer ISE is contributing to the development of use cases for the “MiHyT”, where also a solar firing of the micro hybrid turbine will be evaluated in terms of its techno-economic viability. For the variants investigated at ISE, we are participating in the exploitation planning.

The consortium partner Orcan Energy is developing and building the ORC prototype in the MW power class, while Hochschule Darmstadt is developing, building, and testing the “MiHyT” micro hybrid turbine. Rauschert is developing and manufacturing ceramic components for the “MiHyT”, and CeraFib is developing and manufacturing fiber-reinforced ceramic components.

© h_da
Block diagram of the microhybridturbine „MiHyT“.

Funding

The "MiHyT" project is funded by the Federal Ministry for Economic Affairs and Energy (BMWE) under grant number FKZ 03EE5171A. The project parts of the consortium partners are funded under grant numbers FKZ 03EE5171B, C, D, E.

Sustainable Development Goals

The "MiHyT" research project contributes to achieving the sustainability goals in these areas:

 

Geschäftsfeldthema

Energiesystemanalysen

 

Geschäftsfeldthema

Energiesystemanalysen

Further Information on this Topic

Research Topic

Climate-Neutral Industry

Business Area

System Integration

Key Topic

Climate-Neutral Industry

Business Area

Cooling Technology