Fuel Cell Based System Research Articles

Hydrogen consumption prediction of a fuel cell based system with a hybrid intelligent approach

Energy storage is one of the challenges of the electric sector. There are several different technologies available for facing it, from the traditional ones to the most advanced. With the current trend, it is mandatory to develop new energy storage systems that allow optimal efficiency, something that does not happen with traditional ones. Another feature that new systems must meet is to envisage the behaviour of energy generation and consumption. With this aim, the present research deals the hydrogen consumption prediction of a fuel cell based system thanks a hybrid intelligent approach implementation. The work is based on a real testing plant. Two steps have been followed to create a hybrid model. First, the real dataset has been divided into groups whose elements have similar characteristics. The second step, carry out the regression using different techniques. Very satisfactory results have been achieved during the validation of the model.

A Techno-economic comparison of micro-cogeneration systems based on polymer electrolyte membrane fuel cell for residential applications

This work, developed within the Italian project MICROGEN 30, aims at investigating the benefits of 10kWel Proton Exchange Membrane fuel cell based system with an innovative membrane reformer when applied to a residential application. Results are compared to solutions where a steam reformer is coupled with low temperature or high temperature Proton Exchange Membrane fuel cell stacks. The three cogenerator systems are integrated in a distributed generation scenario, working as suppliers of electricity and heat to two or more residential users. Micro-cogenerators energy and economic balance is evaluated using an in-house software, based on an heuristic algorithm that explores and defines the optimal system operating strategy versus defined load and tariff profiles. The innovative configuration achieves the highest micro-cogeneration economic saving on an yearly basis. The economic analysis also sets the maximum investment cost of the innovative cogenerator system being economically competitive with respect to centralized power generation and conventional boilers.

Investigation of a 5 kW micro-CHP PEM fuel cell based system integrated with membrane reactor under diverse EU natural gas quality

This work investigates the techno-economic assessment of a 5 kW micro-cogeneration system based on membrane reactor and PEM fuel cell flexible towards different natural gas qualities. The flexibility of the system is evaluated for four typical natural gas compositions from different European countries featuring an average condition and three extreme cases. The optimal system design conditions are determined together with performance variation as function of NG composition and load. The sweep gas and vacuum pump are explored as options to reduce the membrane surface area, outlining the efficiency advantages of the former (41.21% vs. 39.24%). Simulations at partial load show that the electric efficiency increases until 60–70% of the load in both cases, then quickly drops. Micro-CHP performance are used as input to determine the specific system target cost (€/kW) based on a yearly energy and economic analysis. The first reveals that the primary energy savings is always positive outlining the environmental benefit of FERRET system application respect to the reference separated production. The target cost considering its application to two dwellings is around 2000 €/kW.

Hybrid energy fuel cell based system for household applications in a Mediterranean climate

In this paper, a specific hybrid energy system was proposed for household applications. The hybrid energy system was assembled from a HT-PEM fuel cell stack supplied by hydrogen via a steam reformer, where finally the majority of produced electricity is used to drive a modified split heat pump system with heat recovery (that is enabled via standard modified accumulation boilers). The system is able to produce both high and low temperature heat output (in the form of hot water), cooling thermal output and electricity. Performance analysis was conducted and the specific hybrid energy system showed high value for overall energy efficiency, for the specific case examined it reached 250%. Levelized Cost of Energy (LCOE) analysis was also carried out and the proposed hybrid energy system’s cost is expected to be between 0.09€/kWh and 0.16€/kWh, which is certainly competitive with the current retail electricity price for households on the EU market. Additionally, the system also has environmental benefits in relation to reduced CO2 emissions, as estimated CO2 emissions from the proposed hybrid energy system are expected to be at around 9.0gCO2/kWh or 2.6 times less than the emissions released from the utilization of grid electricity.

Simulation of Fuzzy Logic Controller for PEM Fuel Cell Based Hybrid Cascaded Multilevel Inverter

The power generated in a proton exchange membrane fuel cell based system depends on the hydrogen and oxygen flows, the regulation of pressure and management of water and heat .One of the important operating variable is the reactant utilization which is directly proportional to fuel cell stack current. When a load is connected to the fuel cell system, the control system must control the flow rate of hydrogen in order to avoid degradation of fuel cell (FC) voltage. Therefore, the objective of the paper is to regulate the input fuel flow to achieve the desired output power. Various control strategies proposed in the literature do not consider the dynamic model of fuel cell system and fuel flow controller. This paper presents the development of fuzzy logic controller for fuel cell based Hybrid Cascaded MultiLevel Inverter(MLI). A MATLAB/SIMULINK control structure for the overall FC based system has been presented which includes the local fuzzy controllers for Interleaved Boost Converter (IBC), HCMLI and the fuel cell. The performance has been compared with PI controller.

Experimental results applying second order sliding mode control to a PEM fuel cell based system

A robust control solution is proposed to solve the air supply control problem in autonomous polymer electrolyte membrane fuel cells (PEMFC) based systems. A Super Twisting controller is designed using a nonlinear model of a laboratory fuel cell test station, even a Lyapunov based stability discussion is included. Subsequently, the proposed control strategy is successfully implemented in the laboratory test bench. Highly satisfactory results are obtained, regarding dynamic behaviour, oxygen stoichiometry regulation and robustness against uncertainty.

Modeling of a 5 kWe tubular solid oxide fuel cell based system operating on desulfurized JP-8 fuel for auxiliary and mobile power applications

An onboard autothermal reformer (ATR) integrated with a SOFC stack offers potential for high energy efficiency and utilization, low emission and quiet operation avoiding cost associated with hydrogen storage and infrastructure. Such a system can be a viable and attractive option especially for military's need for quiet and less pollutant Auxiliary Power Unit (APU) and Mobile Electric Power (MEP) units in temporary and permanent base camps [1,2]. A 5 kWe Solid Oxide Fuel Cell (SOFC) system operating on desulfurized JP-8 fuel was modeled using Aspen Plus process simulation software to examine the effects of oxygen to carbon ratio (O2/C) and steam to carbon ratio (H2O/C) at different ATR operating temperatures (700–850 °C), while keeping the SOFC stack temperature constant at 910 °C. Anode recycle steam and heat have been used to reform the desulfurized JP-8 fuel which would make the system lighter and compact for mobile application. The system modeling revealed a maximum net AC efficiency of 39.5% at 700 °C and a minimum of 32.6% at 850 °C ATR operating temperatures, respectively. Sensitivity analysis with respect to fuel utilization factor (Uf) and current density (j) were also conducted to identify the optimum operating window.

A Fuel Cell Based Propulsion System for General Aviation Aircraft: The ENFICA-FC Experience

The hydrogen and fuel cell power based technologies that are rapidly emerging can be exploited to start a new generation of propulsion systems for light aircraft and small commuter aircraft. Different studies were undertaken in recent years on fuel cells in aeronautics. Boeing Research & Technology Centre (Madrid) successfully flew its converted Super Dimona in 2008 relying on a fuel cell based system. DLR flew in July 2009 with the motor-glider Antares powered by fuel cells. The goal of the ENFICA-FC project (ENvironmentally Friendly Inter City Aircraft powered by Fuel Cells -European Commission funded project coordinated by Prof.Giulio Romeo) was to develop and validate new concepts of fuel cell based power systems for more/all electric aircrafts belonging to a inter-city segment of the market. As a result of the project, a technology demonstrator was designed, manufactured and tested: a new proton exchange membrane (PEM) fuel cell based power system was installed in the Skyleader RAPID200 that had its demonstrative flights in 2010. One of the most critical, if not the most critical, aspect of the all-electric power system adopted for demonstrator is undoubtedly prediction of fuel cell behaviour, specifically in terms of temperature control since reduced volumes and low weights (needed for the aeronautical applications) are not beneficial from a heat-management point of view. Moreover temperature control of PEM fuel cell is extremely important for a correct employment of the cell itself and, since the fuel cell is the main power generating device on the aircraft (batteries are however present as emergency back-up), temperature control becomes a very important safety issue too. In particular, as the ionic conduction of the polymeric membrane is a function of its degree of humidification, the stack temperature has to be carefully controlled to avoid phenomena of water evaporation causing an increase of ohmic drop and a decrease of stack performances. The output power of the fuel cells system is affected considerably by the change of the stack temperature. The paper will report a description of the research activity that lead to the fuel cell based power system developed for the ENFICA-FC project: the main topics will regard the design phase, including numerical and theoretical modelling (validated by flight tests) of the fuel cell system and its cooling, the results of ground testing and installation and, finally, the results of flight testing

Dynamic analysis of PEMFC-based CHP systems for domestic application

Fuel cell-based CHP systems for distributed residential power generation represent an interesting alternative to traditional thermoelectric plants. This is mainly due to the high efficiency obtainable in the production of electricity and heat in a decentralised, quiet and environmental friendly way. The current paper focuses on the development, in Matlab®Simulink environment, of a complete dynamic model of a residential cogenerative (CHP) energy system consisting of the Proton Exchange Membrane fuel cell (PEMFC), fuel processor, heat exchangers, humidifier and auxiliary hot water boiler. The target of the study is the investigation through such a model of the behavior of CHP systems based on fuel cell (FC) at variable electrical and thermal load, in reference to typical load curves of residential users. With the aim to evaluate the system performance (efficiency, fuel consumption, hot water production, response time) and then to characterize its better operating conditions with particular attention to air relative humidity, suitable simulations were carried out. They are characterized by the following of a typical electrical load trend and in relation to two different thermal load profiles. The dynamic model presented in this paper has allowed to observe the fully functioning of the FC based system under variable loads and it has permitted to design appropriate control logics for this system.

An assessment of the energetic flows in a commercial PEM fuel-cell system

Some primary issues have not yet been fully investigated on the way towards the commercialization of fuel-cell-based systems (FCS), e.g., their actual efficiency, reliability, safety, degradation, maintainability, etc. This article deals with an estimation of the real energetic flows and the corresponding electrical efficiency of a commercial proton-exchange-membrane fuel-cell hydrogen-fed generator set (PEMFCS). The fuel-cell power system considered here is planned to be the source of both electrical and thermal energy in a mobile dwelling container unit with in-built fuel-cell-based cogeneration system, and for the design of a cogeneration unit the actual amount of disposable energy from the PEMFC unit should be estimated. The assessment of the actual energetic flows, the disposable energy and the consequent electrical efficiency of the case-study PEMFCS is carried out using commercial technical data for the PEMFCS.

Prospects for hydrogen use in decentralized power and heat supply systems

Possible uses of hydrogen produced from natural gas in fuel cells in decentralized power and heat supply systems are considered. Conditions for the competitiveness of the new technology compared to centralized and decentralized systems based on heat-and-power miniplants with gas-turbine and gas-piston engines are defined. Fuel cell-based systems that use natural gas as fuel are shown to be not energy-saving technologies, although they help reduce the discharges of carbon dioxide and other contaminants to the environment. Large-scale application of fuel cells in decentralized energy-saving systems is only possible if their cost is reduced below $100 per kilowatt.

Hydrogen permeability of multiphase V–Ti–Ni metallic membranes

Development of advanced hydrogen separation membranes in support of hydrogen production processes such as coal gasification and as front end gas purifiers for fuel cell based system is paramount to the successful implementation of a national hydrogen economy. Current generation metallic hydrogen separation membranes are based on Pd-alloys. Although the technology has proven to be successful, at issue is the high cost of palladium. Evaluation of non-noble metal based dense metallic separation membranes is currently receiving national and international attention. The focal point of the reported work was to evaluate a Group 5A-Ta, Nb, V-based alloy with respect to microstructural features and hydrogen permeability. Electrochemical hydrogen permeation testing of the V–Ti–Ni alloy is reported herein and compared to pure Pd measurements recorded as part of this same study. The V–Ti–Ni was demonstrated to have a steady-state hydrogen permeation rate an order of magnitude higher than the pure Pd material in testing conducted at 22 °C.

Testing of a De Nora polymer electrolyte fuel cell stack of 1 kW for naval applications

In a previous study calculations were carried out for a navy frigate with respect to the energy consumption of a propulsion/electricity generation system based on fuel cells. The fuel consumption for the ‘all-fuel cell’ ship was compared with the consumption of the current propulsion/electricity generation system based on gas turbines and diesel engines; it showed potential energy savings of a fuel cell based system amounting from 25 to 30%. On the basis of these results and taking into account various military aspects it was decided to start tests with a polymer electrolyte fuel cell (PEFC) stack. For this purpose a De Nora 1 kW PEFC was chosen. Results of the first tests after installation are satisfying.