Overview
Two of the fuel-cell (FC) technologies most suitable for heavy-duty transport applications are polymer electrolyte fuel cells (PEFC) and solid oxide fuel cells (SOFC). Currently neither technology is capable of meeting the wide-ranging needs of heavy-duty transport because of either low efficiencies (PEFC) or poor transient performance (SOFC). FELICITAS proposed the development of high-power fuel-cell clusters (FCC), which group FC systems with other technologies, including batteries, thermal energy and energy recuperation.
The FELICITAS consortium was the first that undertook the definition of the requirements on FC powertrains for the different heavy-duty transport modes. This contributed to the development of FC powertrain concepts, which, through the use of advanced multiple simulations, undertook evaluations of technical parameters, reliability and life-cycle costs. Alongside the development of appropriate FC powertrains, the consortium undertook fundamental research to adapt and improve existing FC and other technologies, including gas turbines, diesel reforming and sensor systems for their successful deployment in the demanding heavy-duty transport modes.
This research work will combine with the FC powertrains design and simulation work to provide improved components and systems, together with prototypes and field testing where appropriate. The FELICITAS consortium approach substantially improved European FC and associated technology knowledge and expertise in the field of heavy-duty transport.
The objectives defined for FELICITAS were the development of fuel cell drive trains capable to meet the demands of heavy-duty transport for road, rail and marine applications. To achieve these objectives the following parameters were chosen:
- Powerful units of more then 200kW electrical output,
- High reliability and long system durability – >10 000 hours operation time,
- High system efficiency > 60%,
- Operating with different hydrocarbon fuels as well as hydrogen.
As a response to the needs of a range of Heavy-Duty Applications two technologies were included in the Project, SOFC and PEFC technologies. At the start of FELICITAS in 2005 neither technology had demonstrated the ability to meet the objectives above.
FELICITAS focused on:
- SOFC technology – given its comparative immaturity appraisal and feasibility of the technology rather than demonstration in real applications,
- Proton Exchange Membrane (PEM) technology – had began demonstration on a larger scale to be feasible for powering passenger and heavy-duty vehicles such as inner city buses, but degradation mechanisms in operation and durable system technologies were required.
Thus FELICITAS was structured to focus on the most important questions and technological developments to cover the requirements of the different modes of heavy-duty transport.
The FELICITAS project comprised four sub-projects, each focusing on a main topic of fuel cell system and drive train development.
- Subproject I (Application Requirements and System Design) was structured into two work packages:
- WP1: Specification, defining of application requirements and standardisation.
- WP2: System design and simulation.
- Subproject II (Mobile Hybrid SOFC) was structured into four work packages:
- Development and marinization of a 250kW SOFC unit.
- Testing of marinised 60kW sub-system and stationary power 250kW generator module.
- Fuel processing.
- SOFC power management, controller design, and simulation.
- Subproject III (PEFC-Cluster) was broken into three work packages.
- WP III.1 included investigations and configuration activities for fuel cell clusters. This included both the fuel cell system itself and the auxiliaries, the connection to an electrical architecture as well as safety related considerations and finally the design of such a prototype system.
- WP III.2 concentrated on the test activities including investigations and preparation of a close to reality drive cycle and load profile of an inner city transit bus as well as investigations and measures taken to improve operation conditions of the fuel cell systems in a hybrid environment.
- WP III.3 included the integration of the Fuel Cell Cluster into a research vehicle of the Fraunhofer Institute and test operation to verify the function of the overall system.
- Subproject IV (Power Management and Hybridisation) consisted of three work packages:
- Processing of thermal energy.
- Controller design for PEFC-Clusters.
- Components for SOFCPEFC coupling.
The project had been broken down into several phases.
- In the initial phase of the project the partners worked on the theoretical aspects of using the selected fuel cell technologies in heavy-duty applications. This included the definition of application requirements for different transport modes, the principal layout and design for the fuel cell modules and power trains - including on board reforming and turbo machinery for the marine SOFC, as well as system simulations at various stages in such power trains.
- In the development phase, these investigations were evaluated against the available technologies
Funding
Results
Not all the objectives of FELICITAS were achieved due to technical complexity, an unforeseen incident as well as resource and timing issues.
The main objective defined for FELICITAS was the development of fuel cell drive trains capable of meeting the demands of heavy-duty transport for road, rail and marine applications.
In summary:
- The hybrid PEFC clusters were well suited to public transport applications such as buses, light rail or trams in city / town operations.
- The Rolls-Royce hybrid SOFC design would require substantive modification before it could be successfully used in a marine environment.
- Neither hybrid SOFC nor PEFC clusters technologies developed within FELICITAS met the requirements defined for FC systems in heavy rail or tram applications.
- Neither hybrid SOFC nor PEFC clusters technologies developed within FELICITAS met the requirements defined for a FC based main propulsion of heavy-duty trucks.
- Low power SOFC technology in combination with new reformer techniques developed in FELICITAS was well placed for highly efficient APUs in heavy trucks.
The FELICITAS Project achieved the following outcomes:
- A much improved and detailed understanding of the impact of the marine environment, operation and application on a Rolls-Royce SOFC technology, notably a yacht, was achieved.
- Testing of Rolls-Royce SOFC materials and components in marine relevant conditions was successfully undertaken, and the results have substantially increased the appreciation of the marinization challenges for fuel cells.
- Testing of cathode materials and other materials was achieved and results fed back into the knowledge base.
- The Rolls-Royce stack concept and system showed a high mechanical integrity in marine motion conditions.
- A high system efficiency (> 60 %) of hybrid SOFC configurations were verified by detailed simulations and partly by experiments.
- High advanced reformer technologies especially for Diesel and Liquefied Petroleum Gas (LPG) were developed and tested.
- By means of the hybrid PEFC cluster concepts developed in FELICITAS, powerful units of more than 200 kW electrical output are feasible.
- The functionality and the advantages of hybrid PEFC clusters were demonstrated in first test runs of the Fraunhofer AutoTram test vehicle.
- A remarkable increase (doubling) of lifetime could be reached for single PEFC systems in hybrid config
Technical Implications
The FELICITAS Project identified a number of challenges facing the Rolls-Royce SOFC system in the marine environment, the principal electro-chemical issues being potential or actual contamination by sodium chloride and chromium together with possible fuel contaminants where clean fuels are not used. Such challenges require further investigation and probable re-design of the system prior to demonstrating in a marine environment. As such the initial approach of a minimal redesign and modification of the RR SOFC System for stationary power was not feasible, and could not be undertaken within the resources or time frame of the FELICITAS project.