Periodic Reporting for period 3 - Bio-HyPP (Biogas-fired Combined Hybrid Heat and Power Plant)
Reporting period: 2017-12-01 to 2019-12-31
The Bio-HyPP project has aimed at generating and publishing knowledge about hybrid power plants fed by biogas blended with natural gas, consistently improving the efficiency of CHP systems while simultaneously widening the biomass feedstock base as well as increasing operational flexibility. A combined hybrid heat and power plant combines a micro gas turbine (MGT) and a solid oxide fuel cell (SOFC). The hybrid power plant is characterized by high system efficiency with respect to fuel flexibility and optimized subsystems and subcomponents. It is a technology solution for a biogas-fired combined heat and power (CHP) system addressing effectively requirements for highly-efficient, highly load- and fuel-flexible CHP systems with lowest emissions.
The goal of the project has been to demonstrate the Hybrid Power Plant concept as a reliable, cost-effective and fuel-flexible micro-combined heat and power system. The technical objectives of this project have been followed in terms of controllable measures of electric and thermal efficiencies, operating range, operational flexibility, exhaust gas emissions and market and cost reduction potentials of the hybrid power plant.
The focus of the project has been the experimental demonstration of the technology to prove the functional capability of the plant concept, followed by detailed characterization and optimization of the integration of both subsystems MGT and SOFC.
The goal of the project has been to demonstrate the Hybrid Power Plant concept as a reliable, cost-effective and fuel-flexible micro-combined heat and power system. The technical objectives of this project have been followed in terms of controllable measures of electric and thermal efficiencies, operating range, operational flexibility, exhaust gas emissions and market and cost reduction potentials of the hybrid power plant.
The focus of the project has been the experimental demonstration of the technology to prove the functional capability of the plant concept, followed by detailed characterization and optimization of the integration of both subsystems MGT and SOFC.
A life cycle cost analysis (LCCA) has been done on the manufacturing and use phases of a system composed by Bio-HyPP system components. The analyses take into account the production and use phases.
Steady-state thermodynamic simulation models of the top-performance and top-economic layouts have been used to define the specifications. The thermodynamic models have been validated and used for further detailed analysis of the operating range, operation strategies and for defining components’ input conditions for further optimization.
A combustion system, which meets the needs for both SOFC off-gas combustion and biogas/natural-gas-fired combustion has been developed, manufactured, tested under atmospheric conditions and analyzed concerning the operating range. To widen the operating range, adding excess fuel has been analyzed. The combustor for the MGT hybrid test rig has been designed and manufactured. The combustion system and its interfaces have been adapted constructively and have been integrated into the hybrid emulation test and it has been tested on the test rig. Analysis of the combustor in the test rig conditions has been done.
Performance and robustness of the micro gas turbine (MGT) have been improved by efficiency improvements of the turbomachinery components and by power density improvement of the turbine generator.
A significant performance improvement has been obtained, mainly as a result of the combination of small optimisations on the turbomachinery components (introduction of compressor pre-whirl vanes, compressor diffuser vanes, compressor scroll cooling, compressor leading edge modification and modification of turbine heat shield), leading to an 840 W electrical power output increase for the 3 kW MGT.
Designs for the two recuperators for the top-efficiency and the top-economic power plant have been defined. The recuperator effectiveness has been improved as significantly lower costs.
A model predictive control based on multiple tools has been developed for control optimization of the top-economic hybrid power plant. Fluctuations / oscillations could be reduced, so the thermal stress to the SOFC could be decreased. Compressor surge under large variable volumes has been analysed to identify surge precursors. The impact of transient operations (e.g. operations on the cold bypass valve) on the compressor stability have been identified and tested SOFC degradation has been investigated and analysed.
The existing emulation facilities have been upgraded and used for experiments to define necessary valve control and investigation of surge. Models including model predictive controller have been connected to the experimental plant. Different control strategies considering degradation have been evaluated.
Two real subsystems with emulation have been set-up and assembled in the lab: the SOFC test rig and MGT test rig (each emulating the counterpart). Two control systems derived from a joint control concept (for the real coupling) have been developed, commissioned and iteratively adapted.
The top-economic layout has been set up and tested from both theoretical and experimental point of views. Control approaches for the different valves and for part-load operations have been analysed with the simulation tools. Components like recuperator and burner have been designed. Risk mitigation solutions and a plan to involve fire managers have been defined.
The results achieved were disseminated to a wide range of interested audience and stakeholders, thought a Newsletter (8 issues released twice a year), the participation of consortium members at a number of national and international events targeting both the scientific as well as the industrial community, through the publication of scientific articles and publications on the results achieved and the activities carried out and finally throught the website, countinuosly updated during the project with the latest results and news about the project.
Steady-state thermodynamic simulation models of the top-performance and top-economic layouts have been used to define the specifications. The thermodynamic models have been validated and used for further detailed analysis of the operating range, operation strategies and for defining components’ input conditions for further optimization.
A combustion system, which meets the needs for both SOFC off-gas combustion and biogas/natural-gas-fired combustion has been developed, manufactured, tested under atmospheric conditions and analyzed concerning the operating range. To widen the operating range, adding excess fuel has been analyzed. The combustor for the MGT hybrid test rig has been designed and manufactured. The combustion system and its interfaces have been adapted constructively and have been integrated into the hybrid emulation test and it has been tested on the test rig. Analysis of the combustor in the test rig conditions has been done.
Performance and robustness of the micro gas turbine (MGT) have been improved by efficiency improvements of the turbomachinery components and by power density improvement of the turbine generator.
A significant performance improvement has been obtained, mainly as a result of the combination of small optimisations on the turbomachinery components (introduction of compressor pre-whirl vanes, compressor diffuser vanes, compressor scroll cooling, compressor leading edge modification and modification of turbine heat shield), leading to an 840 W electrical power output increase for the 3 kW MGT.
Designs for the two recuperators for the top-efficiency and the top-economic power plant have been defined. The recuperator effectiveness has been improved as significantly lower costs.
A model predictive control based on multiple tools has been developed for control optimization of the top-economic hybrid power plant. Fluctuations / oscillations could be reduced, so the thermal stress to the SOFC could be decreased. Compressor surge under large variable volumes has been analysed to identify surge precursors. The impact of transient operations (e.g. operations on the cold bypass valve) on the compressor stability have been identified and tested SOFC degradation has been investigated and analysed.
The existing emulation facilities have been upgraded and used for experiments to define necessary valve control and investigation of surge. Models including model predictive controller have been connected to the experimental plant. Different control strategies considering degradation have been evaluated.
Two real subsystems with emulation have been set-up and assembled in the lab: the SOFC test rig and MGT test rig (each emulating the counterpart). Two control systems derived from a joint control concept (for the real coupling) have been developed, commissioned and iteratively adapted.
The top-economic layout has been set up and tested from both theoretical and experimental point of views. Control approaches for the different valves and for part-load operations have been analysed with the simulation tools. Components like recuperator and burner have been designed. Risk mitigation solutions and a plan to involve fire managers have been defined.
The results achieved were disseminated to a wide range of interested audience and stakeholders, thought a Newsletter (8 issues released twice a year), the participation of consortium members at a number of national and international events targeting both the scientific as well as the industrial community, through the publication of scientific articles and publications on the results achieved and the activities carried out and finally throught the website, countinuosly updated during the project with the latest results and news about the project.
Within Bio-HyPP, three complementary emulation test rigs have been set up and tested. With these test rigs the interactions of the components solid oxide fuel cell (SOFC) and micro gas turbine (MGT) have been analyzed and a coupling concept has been adapted, verified and published.
Concerning market impact of the project, Bio-HyPP has improved the following MGT components efficiency- and cost-wise: turbomachinery, generator, recuperator and combustion chamber. Experimental investigation showed more than 2%-points efficiency increase of the micro gas turbine. This supports to keep a solid leadership of the EU in advanced energy technologies and increases the competitiveness of the MGT technology.
Concerning energy and environmental impact, the project has moved forward the CO2 friendly technology by developing components and also thermodynamic performance models to find ideal matching for power plant components. With the models including real components’ boundary conditions, it could be shown that 60% efficiency is achieved in certain load points. It also provides the operational area and the tested controller concept for a biogas fired hybrid power plant. The investigations of biogas contribute to the exploitation of this fuel in power generation technology.
The wider societal implications are based on findings around the compressor surge with large cathodic volumes, impacting on the whole international scientific community. Also the redesign of the recuperator has a big impact on knowledge about heat exchangers in so far unknown Reynolds-regions.
Concerning market impact of the project, Bio-HyPP has improved the following MGT components efficiency- and cost-wise: turbomachinery, generator, recuperator and combustion chamber. Experimental investigation showed more than 2%-points efficiency increase of the micro gas turbine. This supports to keep a solid leadership of the EU in advanced energy technologies and increases the competitiveness of the MGT technology.
Concerning energy and environmental impact, the project has moved forward the CO2 friendly technology by developing components and also thermodynamic performance models to find ideal matching for power plant components. With the models including real components’ boundary conditions, it could be shown that 60% efficiency is achieved in certain load points. It also provides the operational area and the tested controller concept for a biogas fired hybrid power plant. The investigations of biogas contribute to the exploitation of this fuel in power generation technology.
The wider societal implications are based on findings around the compressor surge with large cathodic volumes, impacting on the whole international scientific community. Also the redesign of the recuperator has a big impact on knowledge about heat exchangers in so far unknown Reynolds-regions.