Fuel Cell Hybrid System Research Articles

Sensitivity Study of Design Parameters for a Fuel Cell Powered Multirotor Drone

The use of multirotor drones for industrial applications is accelerating, and fuel cell based propulsion systems are highlighted as a promising approach to improve endurance – one of the current main limitations. Due to multirotor drones’ unique requirements, careful system design is needed to maximize the performance advantage. In this work a sensitivity analysis that quantifies the impact of central system parameters for an X8 multirotor drone with a 2 kW fuel cell hybrid system is presented and discussed. Thrust stand measurements identified a 20–30% efficiency loss from the coaxial configuration, and a ‘single’ configuration can reduce power consumption by 700 W at 25 kg take-off mass. Thus, a smaller fuel cell system can be used, giving an additional 1 kg mass saving and 75–140 W power reduction. Peak endurance is found at a 0.67 energy system weight fraction, and if batteries are improved from 180 Wh/kg to 350 Wh/kg, the energy system mass threshold from where fuel cells are superior rises from 7.4 kg to 8.5 kg. At 700 bar, a 3 L hydrogen cylinder can replace a 6 L at 300 bar, provide a 72-min endurance, and is the preferred option to reach minimum system volume. This work provides guidance in early conceptual stages and insights on how fuel cell based powerplants for multirotors can be improved and optimized to increase their value proposition. Further research can expand the work to cover other system variations and do experimental testing of system performance.

Retraction of "Enhanced Electricity Generation and H2O2 Production in a Photocatalytic Fuel Cell and Fenton Hybrid System Assisted with Reverse Electrodialysis".

[This retracts the article DOI: 10.1021/acsomega.9b00282.].

A Degradation Diagnosis Method for Gas Turbine—Fuel Cell Hybrid Systems Using Bayesian Networks

Abstract This paper aims to develop and test Bayesian belief network-based diagnosis methods, which can be used to predict the most likely degradation levels of turbine, compressor, and fuel cell (FC) in a hybrid system based on different sensors measurements. The capability of the diagnosis systems to understand if an abnormal measurement is caused by a component degradation or by a sensor fault is also investigated. The data used both to train and to test the networks are generated from a deterministic model and later modified to consider noise or bias in the sensors. The application of Bayesian belief networks (BBNs) to fuel cell—gas turbine hybrid systems is novel, thus the results obtained from this analysis could be a significant starting point to understand their potential. The diagnosis systems developed for this work provide essential information regarding levels of degradation and presence of faults in a gas turbine, fuel cell and sensors in a fuel cell—gas turbine hybrid system. The Bayesian belief networks proved to have a good level of accuracy for all the scenarios considered, regarding both steady-state and transient operations. This analysis also suggests that in the future a Bayesian belief network could be integrated with the control system to achieve safer and more efficient operations of these plants.

Methanol to power through high-efficiency hybrid fuel cell system: Thermodynamic, thermo-economic, and techno-economic (3T) analyses in Northwest China

Advanced efficient energy conversion technology using clean alternative fuel contributes to the alleviation of the energy crisis and environmental deterioration. In this situation, a novel methanol utilization technology for power generation based on hybrid fuel cell system is proposed in this work. The hybrid system consists of a solid oxide fuel cell (SOFC), a gas processing unit (GP) and a proton exchange membrane fuel cell (PEMFC). Thermodynamic analysis of the system shows that the energy conversion efficiency and exergy efficiency are both higher than the previously reported standalone or hybrid energy systems using methanol as fuel, which are 66.2% and 54.2% respectively. Besides, no recirculation ratio of anode off-gas and moderate fuel utilization of about 0.5 are suggested for the SOFC component to balance the power distribution and improve the efficiency. Afterwards, this hybrid fuel cell system is also investigated from thermo-economic and techno-economic perspectives. Take Northwest China as a case, the 1 MWe methanol-fed power plant has a specific electric energy cost of 0.5594 CNY/kWh, much lower than the methanol steam reforming-PEMFC power plant (2.4 CNY/kWh). At the same time, the sensitivity analyses reveal that the cost of the hybrid power system is not sensitive to the market price fluctuation. With financial subsidies for existing renewable power plants, the payback period can be shortened to 1.4 year and the annual return on investment is about 3.58%. These results reveal that this two-stage fuel cell hybrid system is a kind of efficient and economically methanol to power conversion technology, especially for small power scale.

A novel ammonia solid oxide fuel cell-based powering system with on-board hydrogen production for clean locomotives

Due to the current limitations in hydrogen storage technologies in heavy-duty vehicles, on-board hydrogen production from alternative fuels comes as a viable solution. Ammonia is one type of fuel that can easily be produced and stored in these vehicles. For this reason, this paper aims at presenting a novel powering system that uses ammonia to produce power and hydrogen simultaneously to drive a passenger locomotive. The novelty of the on-board hydrogen production unit is the use of waste heat from a solid-oxide fuel cell hybrid system to disassociate the hydrogen from ammonia. A thermodynamic model based on energy and exergy analyses, which was developed and validated earlier, is used to assess the present novel system. The results of the thermodynamic assessment show that the overall energy and exergy efficiencies of this novel powering system are 61.2% and 66.3%, respectively. The ammonia disassociation and separation thermal processes have a relatively low exergy destruction rate of 1.05 kW. Also, the parametric studies are conducted in this work and the results show that producing more hydrogen enhances the overall energy and exergy efficiencies by only 0.28% and 0.24%, respectively.

A Study on solid oxide fuel cell hybrid system combined with an existing heavy-duty gas turbine to promote the use of hydrogen

A Study on solid oxide fuel cell hybrid system combined with an existing heavy-duty gas turbine to promote the use of hydrogen

Techno-Economic Analysis of Grid-Connected PV and Fuel Cell Hybrid System Using Different PV Tracking Techniques

Solar energy has attracted the attention of researchers around the world due to its advantages. However, photovoltaic (PV) panels still have not attained the desired efficiency and economic mature. PV tracking techniques can play a vital role in improving the performance of the PV system. The aim of this paper is to evaluate and compare the technical and economic performance of grid-connected hybrid energy systems including PV and fuel cells (FC) by applying major types of PV tracking technique. The topology and design principles and technical description of hybrid system components are proposed in this paper. Moreover, this paper also introduces economic criteria, which are used to evaluate the economy of different PV tracking techniques and seek the optimal configuration of system components. In the case study, the results show that the vertical single axis tracker was ranked 1st in terms of highest PV generation, penetration of renewable energy to the grid, lowest CO2 emission, highest energy sold to the grid and lowest purchased, and lowest net present cost (NPC) and levelized cost of energy (LCOE). The study found that the optimal design of a grid-connected hybrid energy system (PV-FC) was by using a vertical single axis tracker which has the lowest NPC, LCOE.

Adaptive real-time optimal energy management strategy based on equivalent factors optimization for hybrid fuel cell system

Fuel cell, a new kind of energy supply equipment, has several advantages such as high efficiency, low noise, and no emission. Proton exchange membrane fuel cell (PEMFC) is considered to have the potential to take the place of the conventional engine on unmanned underwater vehicle (UUV). Besides the power sources in the hybrid power system, the energy management system (EMS) is crucial to operating performance. In this paper, an on-line adaptive equivalent hydrogen consumption minimization strategy (ECMS) is proposed to solve the problem of prior knowledge demand and poor adaptability of current energy management algorithms. In this presented method, a battery state of charge (SOC) constituted penalty term is designed to calculate the equivalent factor (EF), and then the equivalent factor obtained by optimization is substituted into the original objective equation to realize the real-time energy regulation. In this paper, a typical UUV load curve is used to verify the control effect under different working conditions, and the performance is compared with three conventional algorithms’. Simulation results show that the hydrogen consumption of proposed algorithm is close to the optimal solution obtained in offline environment, and it is reduced by more than 3.79% compared with the traditional online methods.

A hybrid fuel cell system integrated with methanol steam reformer and methanation reactor

In this paper, a hybrid fuel cell system integrated with methanol steam reformer and methanation reactor is demonstrated. Methanol steam reformer employed in this system is to produce hydrogen-rich reformate in connection with a methanation reactor to reduce the carbon monoxide content effectively, and the reformate gas is sent into a low-temperature polymer electrolyte fuel cell for direct electric power generation. The optimum conditions (temperature, water to methanol ratio, and space velocity) for methanol steam reforming (MSR) reaction and methanation (MET) reaction are verified by experiments. A comparison between pure hydrogen, reformate surrogate, and actual reformate is performed. The results show that the power density of this hybrid system achieves 245.2 mW/cm2 while it achieves 268.8 mW/cm2 when employing pure hydrogen as the fuel. An alternative novel method to solve the problem of hydrogen storage and transportation is provided and the in-situ hydrogen production and utilizing through low-temperature fuel cell system is realized, which is helpful to accelerate the commercialization process of the fuel cell.

Coupled inductors design of the bidirectional non‐inverting buck–boost converter for high‐voltage applications

This work analyses the effects on the efficiency of the winding-to-winding capacitance of the coupled-inductor of the bidirectional non-inverting buck–boost converter in high-voltage applications. This converter presents many advantages that make it suitable for low-voltage hard-switching photovoltaic and fuel cell hybrid systems. However, experimental results obtained using the previously reported procedure to implement the coupled inductors show low-efficiency in high-voltage applications. A different implementation procedure of the coupled inductors, with lower winding-to-winding capacitance, is proposed. High-efficiency experimental results from a 400 V 1.6 kW prototype have been achieved over a wide operating voltage range, thanks to the use of SiC devices and the modified coupled inductors, confirming in this way its good potential as a building block also in high-voltage wide-gain-range applications.

A multi-method control strategy for numerically testing a fuel cell-battery-supercapacitor tramway

A fuel cell-battery-supercapacitor powertrain, for railways, is investigated and numerically modelled. Each main powertrain component, such as energy sources, power electronic and drivetrain components, is analysed in detail; electrochemical, logic and physic equations are used to design the models, formalizing and implementing them in Matlab-Simulink. To achieve a proper behaviour and high performance, two control strategies are implemented: an ad-hoc power-sharing system, designed for railways, that connects principles of global drive-cycle knowledge and real-time methods; a motor control, composed of a proportional-integral speed and a direct torque control. Therefore, the controllers can take advantage of the powertrain component peculiarities, selecting a proper role for each energy source, and accurately manage the electric motor. The fuel cell-based powertrain is tested on a real urban route, offering a public service from/to the University of Calabria. The simulation results are investigated on different levels of details: a meticulous energy efficiency and performance analysis is conducted. The output power and hydrogen consumption (approximately 0.3 kg/km) are examined and losses and efficiencies of each component are evaluated, reaching 42.5% overall vehicle efficiency, in order to study the energy flux and form conclusive considerations regarding the pros and cons of fuel cell hybrid systems for railways.

Modelling of Photovoltaic, Fuel Cell and Battery Hybrid System Connected to Non-Linear Load

Modelling of Photovoltaic, Fuel Cell and Battery Hybrid System Connected to Non-Linear Load

Performance analysis of a fuel cell hybrid system subject to technological uncertainties

Nowadays research in energy field is focused on conversion technologies which could achieve higher efficiencies and lower environmental impact. In such a context, fuel cells in general and pressurized solid oxide fuel cell (SOFC) hybrid systems are attractive for their high electric efficiency, potential for cogeneration applications, low carbon emissions and high performance at part-load. The aim of this work is to perform the design under uncertainty of an innovative turbocharged hybrid system, where a turbocharger is used to pressurize the fuel cell, featuring better cost effectiveness than a microturbine-based hybrid system at small scales (<100kWe). In this study, a response surface of the plant steady-state performance is developed considering the main operating parameters (fuel cell area, stack current density and recuperator exchange surface) as factors to create the metamodel, taking into account the uncertainties related to the turbocharger efficiency and to the ohmic losses of the fuel cell stack. The optimal economic design of such a turbocharged hybrid system is then analysed at off-design conditions, to preliminary assess the operating costs and profitability within the Italian market scenario considering the variability of fuel and electricity prices. Finally, the impact of uncertainties both on plant performance and economics are discussed, showing that both payback period and internal rate of return present a significant variability, mostly due to the uncertainties related to the prices, showing that a proper evaluation of the evolution of the prices along the years should be performed for a proper economic feasibility analysis.

Combined biomass gasification, SOFC, IC engine, and waste heat recovery system for power and heat generation: Energy, exergy, exergoeconomic, environmental (4E) evaluations

A novel hybrid system using biomass as fuel for both power and heat generation, which consists of biomass gasification unit, solid oxide fuel cell, homogeneous charge compression ignition engine and waste heat recovery unit, is proposed in this work. Based on the modeling, the system is comprehensively evaluated by multiple approaches including energy, exergy, exergoeconomic and environmental analyses. It is found that the overall energy efficiency and exergy efficiency of the hybrid system could reach up to 68% and 51%, both of which are comparable to those of other reported hybrid fuel cell systems. The exergy destruction of the gasifier is the largest whose relative exergy destruction is up to 21.5%. The component of fuel cell contributes to 71% of the total power but with small relative exergy destruction. On the contrary, the HCCI engine contributes to less power but has larger exergy destruction compared to SOFC. The exergoeconomic analysis showed that the fuel cell component has a high exergoeconomic factor of 98.09% due to the large capital investment cost. By comparison, the component engine has much lower exergoeconomic factors of 5.41%. The cost of exergetic product of the hybrid system is 9.7 $/GJ. Besides, the proposed hybrid system presents a low carbon dioxide emission of about 0.119 to 0.139 t/GJ, which indicates few environmental impacts for the system. These results reveal that the proposed biomass-fueled hybrid system is high-efficiency, low-cost and clean for both power and heat generation, which could be promising candidate as advanced energy conversion technology in practical applications.

Evaluation of design methodology, limitations, and iterations of a hydrogen fuelled hybrid fuel cell mini UAV

Fossil fuels are being depleted day by day. The dependency on fossil fuels must be eliminated in the following years. Also, in the matter of emissions, the cleaner energy generation and usage techniques must be evaluated. The aviation industry is a big energy consumer nowadays. More electric aircraft and All-electric aircraft concepts are being worked on globally to achieve a sustainable aviation industry. Though the electric motors can produce enough thrust force for airliners, due to energy storage technology limitations, the thrust force can’t be sustained for a long duration flight. Battery technologies are being developed to overcome these limitations. Moreover, hybrid energy systems and sustainable onboard energy generation systems are trending to achieve sustainability. Fuel Cell and Hybrid Fuel Cell systems are two of the feasible onboard energy systems. The applications of these systems on UAVs (Unmanned Aerial Vehicle) produce data for later studies. The system’s behavior during flight phases must be examined on platforms like mini UAVs to understand the system capabilities. In this work, the development phases of a mini UAV designed for Hybrid Fuel Cell flight are introduced. Design philosophy and methodology for designing a UAV with a hybrid propulsion system, limitations of such designs and iterations required during the flight tests are explained. Also, the detailed design estimations of power consumption and final power consumption data collected from flight tests of the aircraft were compared to provide valuable data for following power consumption limited aircraft design studies.

Suitability Analysis of Implementing a Fuel Cell on a Multirotor Drone

Increased flight time of multirotor drones is a key enabler for further adoption and industrial use of drones. A model for analyzing the performance of a fuel cell hybrid system for a multirotor drone is presented and applied for a case with an X8 multirotor drone with a maximum take-off mass of 25 kg. Endurance is the main performance parameter, and the model can be used to quantify the relative performance between different power sources. The model aims to determine if a specific hybrid fuel cell system is a viable option for a given multirotor drone and if it will provide better endurance than when powered by batteries. The model can also be used in system optimization and sensitivity analysis. In a case study, a fuel cell hybrid system with a 7.2 L cylinder with hydrogen at 300 bar is found to increase the flight time by 43 minutes (+76%) from the currently used LiPo-batteries. A plot identifies the energy system mass threshold for when the fuel cell hybrid system gives better endurance than batteries to be 7.3 kg. Based on current technology status, the cost of a fuel cell hybrid system is about 12 times that of LiPo-batteries.

Economic performance of multi-energy supply system in a zero-carbon house

Due to the improvement of people's living standards, uptake of multi-functional household appliances, electricity consumption accounts for a rising ratio in the proportion of primary energy usage. Currently, electricity accounts for more than 50% of primary energy usage and city gas is about 21% of total. The aim of this research focus on improving the efficiency of household energy usage and optimizing the economy of residential energy systems. This paper classified the detail electricity consumption and generation for a Japan typical household with Hybrid Fuel cell and Photovoltaic System (HFPS) based on the history monitored data. Then a simulation model of the Hybrid Heat pump and Photovoltaic System (HHPS) was designed under the same user load for analyzing the energy consumption. Finally, the economy of the two systems is compared and optimized by considering the carbon tax, equipment price and energy price fluctuation. In general, by comparing the environmental and economic performances of both two systems, the results showed that HFPS has a better environmental performance than HHPS, but HHPS presented an economic advantage over HFPS. In addition, with the change of equipment price and the development trend of energy price in the future, the economic performance of HFPS is gradually improved, which is better than HHPS and has more development prospects. The results of this work provide policy guidance for the future Japanese government's promotion of residential fuel cell systems, while choosing the optimal path between user energy characteristics and power contract scheme.

Conceptual design analysis for a lightweight aircraft with a fuel cell hybrid propulsion system

ABSTRACT With the ever-growing aviation industry, energy researches on aviation have turned to renewable energy sources providing electric propulsion. Fuel cells are one of the most popular sources of power for electric vehicles terms of being greener, more reliability, and higher efficiency. Among fuel cells, the most attractive option for flight is polymer electrolyte membrane fuel cells (PEMFC). This paper aims to compose of a hybrid propulsion system to a lightweight aircraft Cri-Cri for more electric aircraft concept. For this purpose, first, conceptual a hybrid propulsion system is designed for the prototype aircraft. The fuel-cell hybrid system proposed for this paper consists of electric motor, fuel cell system, battery, DC/AC converter, and DC/DC converter. Second, some analyses are done. These analyses contain required power, hydrogen consumption, energy consumption, etc.. As a result, Cri-cri needs 26 Kw during take-off, 30 Kw during climb, 10 kW during cruise, and 7 kW during descent. It also consumed 0.75 kg of hydrogen in total, including 0.21 kg in the take-off and climb, 0.42 kg in the cruise, and 0.12 in the descent. The remaining 0.25 kg of hydrogen is reserved for use in emergencies. The total amount of energy consumed is 33 kWh.

Multi-Stack Lifetime Improvement through Adapted Power Electronic Architecture in a Fuel Cell Hybrid System

To deal with the intermittency of renewable energy resources, hydrogen as an energy carrier is a good solution. The Polymer Electrolyte Membrane Fuel Cell (PEMFC) as a device that can directly convert hydrogen energy to electricity is an important part of this solution. However, durability and cost are two hurdles that must be overcome to enable the mass deployment of the technology. In this paper, a management system is proposed for the fuel cells that can cope with the durability issue by a suitable distribution of electrical power between cell groups. The proposed power electronics architecture is studied in this paper. A dynamical average model is developed for the proposed system. The validation of the model is verified by simulation and experimental results. Then, this model is used to prove the stability and robustness of the control method. Finally, the energy management system is assessed experimentally in three different conditions. The experimental results validate the effectiveness of the proposed topology for developing a management system with which the instability of cells can be confronted. The experimental results verify that the system can supply the load profile even during the degradation mode of one stack and while trying to cure it.

High-efficiency conversion of natural gas fuel to power by an integrated system of SOFC, HCCI engine, and waste heat recovery: Thermodynamic and thermo-economic analyses

A novel natural gas utilization system for power generation including solid oxide fuel cell (SOFC) and homogeneous charge compression ignition (HCCI) engine is proposed and modeled to evaluate the thermodynamic and thermo-economic performance in this paper. The results show that the SOFC-HCCI engine hybrid system has a net electrical efficiency of approximately 59% and the exergy efficiency of 53.5%, both of which are more than single fuel cell system and comparable to other hybrid fuel cell systems. It is also found that the SOFC contributes to the total power of 80% and has a relatively low exergy destruction. Through the parametric analysis, the power distribution between SOFC and engine can be adjusted by controlling SOFC fuel utilization to optimize the system overall performance. Besides, the specific electric energy cost of the proposed hybrid system is calculated to be 6.91 ¢/kW h, which is comparable to the specific cost of electric power (6.92 ¢/kW h) generating from a biogas-fueled fuel cell hybrid system. The payback period and annual return on investment can reach 1.53 year and about 6.41%. These results reveal that the proposed conversion technology of natural gas fuel to power is efficient and economical, which could be a promising natural gas fuel utilization.