Fuel Cell

Stringent emission regulations combined with customer demands for improved fuel economy and performance have forced the automotive industry to consider more advanced powertrain configurations than standard port-fuel injected gasoline engines. Modern state-of-the-art powertrain systems may combine several power sources (internal combustion engines, electric motors, fuel cells, etc.) and various exhaust aftertreatment devices (catalytic converters, lean NOx traps, particulate filters, etc.) in addition to conventional engine subsystems such as turbochargers and exhaust gas recirculation. The determination of the way in which these systems need to be operated to meet driver's torque demand, performance and fuel economy expectations while satisfying federal emission regulations is a complex and a multiobjective optimal control problem. This paper reviews some of the approaches to this problem in the context of two case studies

As climate change becomes a more widely recognized global problem, electrical propulsion of vehicles appears to be a promising solution to cut green house gases emissions. While the automotive industry makes rapid strides towards a mature electric car market, very few initiatives have arisen in the maritime sector thus far. Existing recreational electric boats are often powered either by batteries only, photovoltaic panels and batteries, or fuel cell and batteries, with range and performances dependent upon sun radiation and hydrogen storage capacity. This study contemplates an electric propulsion system for a boat, encompassing battery, photovoltaic panels and a hydrogen fuel cell, which provide incomparable range and flexibility of use. This propulsion system has been designed for a 1/8 scale model (2 m long) of the Hidrocat catamaran in order to reach required speed and to offer suitable range. The elements of the propulsion system have been characterized individually in a laboratory and a simulation model has been created based on this testing campaign. It permits simulation of various sailing schemes as well as study and prediction of energy flows and consumptions. Several trials with the catamaran scale model were conducted while monitoring the circuit components. The experimental data acquired during live testing of the scale model were compared to the output of the simulations and both were consistent which confirmed the reliability of the simulator model. The behaviour of the propulsion system encompassing two renewable sources energy was efficient and the technological choices have been validated.

Pt nanoparticles were supported on Sb2O5.SnO2 (ATO), on carbon and on physical mixtures of ATO and carbon by an alcohol-reduction process using ethylene glycol as reducing agent. The obtained materials were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Their performance for ethanol oxidation was investigated at room temperature by chronoamperometry and in a direct ethanol fuel cell (DEFC) at 100 °C. Pt nanoparticles supported on a physical mixture of ATO and carbon showed a significant increase of performance for ethanol oxidation compared to Pt nanoparticles supported on ATO or on carbon.

Recent improvements in fuel cell technology along with an increasing demand for small generator units have led to renewed interest in dispersed generation units. This work demonstrates a methodology for deploying dispersed fuel cell generators throughout a power system to allow for more efficient operation. A detailed study of the system losses and sensitivities on Eastern Washington system as part

This paper describes the RT-LAB real-time simulator implementation of the Hardware-In-the-Loop simulation of a fuel cell hybrid electric vehicle system with several 10 kHz converters. The paper demonstrates the necessity to use special IGBT bridge models that implements interpolation techniques within fixed time step simulation scheme. The paper reports on the latest advances from Opal-RT to simulate this kind of system with a 10 µs sample time. HIL computational time measurement are provided as well as a model fidelity comparison made by Toyota Motor Corp. of the RT-LAB Electrical Drive Simulator versus an actual fuel cell hybrid electric vehicle. In this paper, we describe an the methodology and simulation techniques used to make the real-time simulation of a fuel-cell hybrid vehicle with DC-DC converter and several PMSM inverter drives running with 10 kHz carrier frequency. The paper is organized in the following manner. First, typical problems regarding the real-time simulation ...

The notion of dominant designs deals with dominance in the market and the dominant design is thought to be dominant because of market selection forces. The notion thus ignores the possible selection that takes place in pre-market R&D stages of technological trajectories. In this paper we ask the question whether pre-market selection takes place and if this can lead to

The direct ethanol fuel cell (DEFC) is a promising fuel cell device, which could provide power to portable and microelectronic equipment in the future. In the present investigation, the influence of a pore-former, polytetrafluoroethylene (PTFE) and catalyst loadings in the electrocatalyst of the anode on DEFC performance is studied. The decal transfer method is used to prepare the membrane electrode assembly (MEA) using PtRu/C (40:20% by wt) as the anode catalyst, and Pt/C (40% by wt) as the cathode catalyst, a pore-former, PTFE dispersion and Nafion ionomer. The pore-former used is 10% (by wt) NaHCO3 in the catalyst ink during the preparation of MEA. The voltage-current characteristics of DEFC were monitored at different loadings of the catalyst, PTFE and a pore-former in MEA. The DEFC performance improved with the use of a pore-former and higher loading of PTFE in MEA. Higher DEFC performance is obtained because PTFE, along with the network of pores in the anode side allowed easy removal of reaction species, thereby rendering the catalyst site available for ethanol oxidation. Further, the use of a pore-former and PTFE at the anode allowed higher loading of electrocatalyst resulting in an increase in the performance of DEFC. The DEFC, with 1 mg cm−2 of catalyst loading at the anode and cathode, 10% (by wt) NaHCO3 of a pore-former, 20% (by wt) PTFE loading in catalyst ink gives maximum power density of 8.5 mW cm−2 at a current density of 31.3 mA cm−2. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.

A novel sulfonated diamine monomer, 1,4-bis(4-aminophenoxy)-naphthyl-2,7-disulfonic acid (BAPNDS), was synthesized. A series of sulfonated polyimide copolymers were prepared from BAPNDS, 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) and nonsulfonated diamine 4,4′-diaminodiphenyl ether (ODA). Flexible, transparent, and mechanically strong membranes were obtained. The membranes displayed slightly anisotropic membrane swelling. The dimensional change in thickness direction was larger than that in planar. The novel SPI membranes showed higher conductivity, which was comparable or even higher than Nafion 117. Membranes exhibited methanol permeability from 0.24 × 10−6 to 0.80 × 10−6 cm2/s at room temperature, which was much lower than that of Nafion (2 × 10−6 cm2/s). The copolymers were thermally stable up to 340 °C. These preliminary results have proved its potential availability as proton-exchange membrane for PEMFCs or DMFCs.

Distributed power generation is the future trend due to its ability to accommodate variety of renewable/alternative energy sources, its potential to improve the energy efficiency and power system capability, and its promise for power reliability and security. Many distributed energy sources exists such solar energy, fuel cell, micro turbine, and wind energy. Distributed power generation concept has been implemented in

In this paper, an energy system comprising three energy sources, namely PV, wind and fuel cells, is proposed. Each of the three energy sources is controlled so as to deliver energy at optimum efficiency. Fuzzy logic control is employed to achieve maximum power tracking ...

A 3D numerical study was carried out to analyze flow, heat and mass transfer first in a single half-cell cathode channel of proton exchange membrane (PEM) fuel cell. From practical point of view, it is necessary to put the appropriate number of cells in a stack. Hence, the above study on a single half-cell is extended to a stack of channels. Due to stacking, the assumption of uniform flow distribution would no longer hold true. Therefore, the channel flow-maldistribution is considered. The water formed at the active surface due to the electrochemical reaction diffuses through the porous layer and eventually enters the gas flow duct. The higher gas velocities in the duct result in faster water vapour removal which leads to a lower value of water vapour into the duct and hence a lower Nusselt number.

Distributed power generation is the future trend due to its ability to accommodate variety of renewable/alternative energy sources, its potential to improve the energy efficiency and power system capability, and its promise for power reliability and security. Many distributed energy sources exists such solar energy, fuel cell, micro turbine, and wind energy. Distributed power generation concept has been implemented in

This paper presents a dynamic model of a fuel cell system for residential power generation. The models proposed include a fuel cell stack model, reformer model and DC/AC inverter model. Furthermore a fuzzy logic (FLC) controller is used to control the active power of PEM fuel cell system. The controller modifies the hydrogen flow feedback from the terminal load. Simulation results confirmed the high performance capability of the fuzzy logic controller to control power generation. K e y w o r d s: polymer-electrolyte fuel cell, dynamic model, residential power, fuzzy controller