Papers by Hydrogen, Fuel Cell & Energy Storage
Hydrogen, Fuel Cell & Energy Storage, 2023
The present study uses lubricated and non-lubricated stamping processes to fabricate metallic bip... more The present study uses lubricated and non-lubricated stamping processes to fabricate metallic bipolar plates (MBPPs) with a thickness of 0.1 mm from SS3316 with a serpentine flow field. Then, experimental tests, together with the finite element (FE) model, were utilized to define the directional thickness distribution. According to the results, using a friction factor of 0.1 during the FE analysis can provide accurate results in terms of thickness prediction under lubricated conditions. Furthermore, the largest thinning percentages in the modified conditions were found to be 27.02%, 30.40%, and 26.00% in the longitudinal, diagonal, and transverse directions, respectively, indicating that the diagonal direction is the most critical one. Finally, the effect of the lubricating condition on the wrinkling of the sample was investigated. According to the results, using the lubricated condition during the stamping process augments the wrinkling of the bipolar plate, and the wrinkling of the bipolar plate's margin was not symmetrical.
Hydrogen, Fuel Cell & Energy Storage, 2023
One of the parameters that play an important role in the efficiency of polymer electrolyte membra... more One of the parameters that play an important role in the efficiency of polymer electrolyte membrane fuel cells (PEMFCs) is the contact pressure between the bipolar plates and membrane electrode assembly (MEA). Increasing or decreasing the contact pressure between the plates causes ohmic losses and decreases the efficiency of the fuel cell. In this research, the contact pressure distribution over the MEA in the three-cell fuel cell stack with metallic bipolar plates with an active area of 100 cm2 was investigated numerically and experimentally. Abaqus finite element software has been used for finite element simulation. Due to the asymmetry of the flow field of metallic bipolar plates, a full three-dimensional model has been used for simulation. In order to experimentally investigate the contact pressure distribution on the MEA, the pressure sensitive film of Fujifilm was used. Considering that the fuel cell stack includes three cells, pressure sensitive film is used in the middle cell and thin insulating plates are used in the first and third cells. Finally, after disassembling the fuel cell stack and separating the pressure sensitive film, the experimental test results are compared with the simulation results. The simulation results showed that the pressure changes on the active area are less than 0.3 MPa. The average contact pressure on the active area with a press force of 3.7 tons is about 1 MPa. Also, the results of the experimental tests were in good agreement with the simulation results.
Hydrogen, Fuel Cell & Energy Storage, 2023
In this study, a novel multigeneration cycle for hydrogen and freshwater production, including PT... more In this study, a novel multigeneration cycle for hydrogen and freshwater production, including PTC and geothermal as the primary energy sources and Kalina and ORC cycles as the main power production cycles, has been proposed and analyzed from an energy and exergy point of view. The effect of important parameters, including solar irradiation, collector inlet temperature, collector volumetric flow, environment temperature, and geothermal temperature, on the amount of hydrogen production rate, freshwater production rate, and system efficiency have been investigated. The results show that the energy and exergy efficiency of the proposed system is 35.75 % and 18.39 %, respectively. Moreover, the total power produced by the system is 1545 kW, the amount of hydrogen produced is 0.001175 g/s, and the freshwater production rate is 5.216 kg/s. Furthermore, the results indicated that increasing geothermal temperature and solar collector inlet volumetric flow increases hydrogen production rate. In contrast, solar irradiation and environment temperature have no effects on the hydrogen production rate of the cycle. Finally, it was found that geothermal temperature increase and collector volumetric flow show an optimum point for thermal efficiency and freshwater, respectively.
Hydrogen, Fuel Cell & Energy Storage, 2023
Improving the subsea endurance and the power system efficiency of unmanned underwater vehicles (U... more Improving the subsea endurance and the power system efficiency of unmanned underwater vehicles (UUVs) has become more important in recent years as their growing demands in different applications. Integrated electric power systems are commonly applied in UUVs with different types of batteries as power sources. Utilizing fuel cells hybridized with batteries is one of the most efficient ways to increase the UUV's range and overall system efficiency. In this paper, a conceptual design is presented for fuel cell/battery hybrid UUV. To elaborate on the design process, the UUV fuel cell stacks, the commercial fuel cell UUVs, the technologies of the fuel and oxidant storage, and the electrical energy storage subsystems are reviewed. Also, analytical investigations have been presented on the degree of hybridization (DOH) between fuel cells and batteries. The fuel cell/battery hybrid system for UUV is designed and the technologies of its main components are proposed as the final step of the conceptual design process.
Hydrogen, Fuel Cell & Energy Storage, 2023
The main target of this research is to model, analyze, and compare the performance of two hybrid ... more The main target of this research is to model, analyze, and compare the performance of two hybrid systems,, 1. A gas turbine (GT) and steam Turbine (ST) plus a solid oxide fuel cell (SOFC) and 2. a hybrid GT, ORC, and SOFC cycle (SOFC+ GT+ ORC) from the thermodynamic and exergy perspectives. Studies show that the output power of a combined system with a steam cycle is higher than that of a system with an organic Rankine cycle, but this higher output does not necessarily mean that this cycle performs better. Therefore, a steam cycle at a higher power range and turbine inlet gas temperature is more justified. The results show that among the analyzed fluids, the use of toluene fluid in the organic Rankine cycle produces the most power at a condenser temperature of 319 Kelvin.
Hydrogen, Fuel Cell & Energy Storage, 2023
Proton ion conducting nano crystalline yttrium doped barium cerate (YBCO) is synthesized by ethyl... more Proton ion conducting nano crystalline yttrium doped barium cerate (YBCO) is synthesized by ethylene glycol and citric acid assisted sol–gel method. In this paper two different kinds of BaCe 0.9Y0.1O 3-a nano composites were prepared. YBCO (I) have been synthesized by [(Ce2(pydc)4(H2O)4].pyda.H]2.2H2O, {[Ba1.5 (pydc.H) (pydc) (H2O) ]. H2O. 0.5 (pydc.H2)}n, [(Y2 (pydc)4 (H2O)4].pyda.H]2.2H2O]], [pydc (2,6-Pyridinedicarboxylic acid), pyda (2,6-diaminopyridine)] and YBCO (II) was synthesized by by (Y(NO3)2.6H2O, Ba(NO3)2, Ce(NO3).6H2O). The powders of (I) and (II) was calcined for a period of 8 hours at 900 °C to get the fine yttrium doped barium cerate powders and the specifications were compared. Various analytical techniques have been used for characterization of the samples, such as scanning electron microscope (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), thermal analysis TG/DTA and X-ray powder diffraction (XRD) used. The results showed that the powders synthesized by metal complexes containing LH2 ligand as precursors, were denser, more homogeneous with smaller particle sizes. The experimental results showed YBCO (I) effectively improve the electrochemical performance of the electrolyte.
Hydrogen, Fuel Cell & Energy Storage, 2022
Sealants are one of the most important components of proton exchange membrane fuel cells (PEMFCs)... more Sealants are one of the most important components of proton exchange membrane fuel cells (PEMFCs). They play significant roles in fuel cells' safety, energy density, durability, and performance. Thus choosing the proper kind of sealant suitable for PEMFCs is essential for the performance of the fuel cells.. The seal's durability gives it the ability to correctly perform the sealing function in the fuel cell environment for an extended amount of time with only small changes in its physical and chemical properties. In this paper, the mechanical properties of three materials frequently used for fuel cell sealing are assessed in an environment similar to actual fuel cells. These three materials are silicone, EPDM (ethylene propylene dyne monomer) sheet, and molded EPDM. Mechanical properties of the materials were obtained after being used in an environment resembling a fuel cell for a specific time and temperature. The specimens' mechanical and chemical properties, such as hardness, weight changes, tensile strengths, compression set, and spectrometry, were determined in an accelerated durability test in the simulated PEMFC environment. These tests were conducted over a period of 100 days. The results revealed that molded EPDM is the best of the tested sealants based on the obtained properties in fuel cell working conditions.
Hydrogen, Fuel Cell & Energy Storage, 2022
Nowadays, study on alternative sources of fossil fuels for power generation has attracted great a... more Nowadays, study on alternative sources of fossil fuels for power generation has attracted great attention. Polymer electrolyte membrane fuel cells (PEMFCs) have higher energy densities and lower power densities than conventional batteries. Therefore, PEMFCs should be hybridized with a battery to increase the stability without decreasing the maximum power. Typically, DC-DC converters are utilized to combine these systems leading to a significant increase in cost, size, and weight; moreover, using these converters reduces system efficiency. In this paper, a circuit is implemented into the PEMFC and battery hybridization system with a power path controller. The experimental investigations covers the main challenges in the PEM fuel cell power system implementation, i.e., current ripple and electric power changes dynamics. This circuit implementation increases the system efficiency over 95 percent and decreases the cost by at least 50 percent. The hybridization circuit is verified by simulation and experimental results.
Hydrogen, Fuel Cell & Energy Storage, 2022
In this study, nickel oxide-gadolinium doped ceria, NiO-GDC, composite powder was synthesized by ... more In this study, nickel oxide-gadolinium doped ceria, NiO-GDC, composite powder was synthesized by the sol-gel method with a new Ni(II) complex. A new Ni(II) complex, chemical formula [Ni(μ-L)] n (NO 3) 2 , L = N'-(pyridine-2-yl)methylene) isonicotinohydrazide), was used as a new precursor. The new Ni(II) complex was prepared by a reaction between ligand, L, and Ni(NO 3).6H 2 O using the hydrothermal method. Then the NiO-GDC powders were synthesized using Ce(NO 3) 3 .6H 2 O, and Gd(NO 3) 3 .6H 2 O, and the as-synthesized new Ni(II) complex [Ni(μ-L)] n (NO 3) 2 with the sol-gel method. The NiO-GDC powder was modified to increase the performance of solid oxide fuel cells (SOFCs) operating at intermediate temperatures (600-800 ℃) by increasing the three-phase boundary region in the anode. Finally, the NiO-GDC anode powders prepared with the new precursor were compared with the NiO-GDC anode powders synthesized from metal nitrates as a precursor. The results showed that the modified NiO-GDC anode had more three-phase boundaries, TPB, a more uniform microstructure, a higher specific surface area, and a porous structure that effectively improved the electrochemical performance of the electrode. SOFC half-cell resistance with this high-performance anode decreased by 85 % at 800 ℃ compared to conventional half-cells.
Hydrogen, Fuel Cell & Energy Storage, 2022
High step-up DC-DC converters are considered the main components of some lowvoltage and low-power... more High step-up DC-DC converters are considered the main components of some lowvoltage and low-power fuel cell power system applications. A new DC-DC converter topology based on a two-stage switched capacitor-switched inductor multiplier is proposed in this paper. In comparison with other conventional and high step-up DC-DC converters, the proposed converter topology provides higher voltage gain and lower switch voltage stresses for duty cycles in the range of 0.6 or higher, the typical duty cycle of high step-up DC-DC converters. The proposed converter consists of a novel combination of switched capacitors and switched inductors methods that reduce the number of required switches and their duty cycles. The theoretical analysis was confirmed by simulation results in MATLAB/Simulink software environment results. A 100 W laboratory prototype of the proposed converter was implemented to investigate and validate the analytical and simulation results. The prototype DC-DC converter was designed and implemented for use in a commercial 100 W PEM fuel cell stack power system.
Hydrogen, Fuel Cell & Energy Storage, 2022
In this study, the fracture method is used to numerically and experimentally investigate the bend... more In this study, the fracture method is used to numerically and experimentally investigate the bending load of graphite-based composite bipolar plates of polymer electrolyte membrane fuel cells. First, simple and perforated composite bipolar plates were tested and simulated to determine flexural stability under static load. Then, mechanical simulation using the finite element method and Abaqus software was used for the numerical analysis. Next, an experimental three-point bending test was performed on the manufactured samples to validate the simulation results. Finally, the results of the numerical and experimental analyzes of the flexural behavior of composite bipolar plates were compared. The results demonstrated that the numerical results acceptably agreed with the experimental data. In addition, the presence of a high percentage of graphite and high fragility weakened the body due to the molecular bond of graphite, which caused the graphite to slip.
Hydrogen, Fuel Cell & Energy Storage, 2022
One of the most important components of a polymer electrolyte membrane fuel cell is the endplate,... more One of the most important components of a polymer electrolyte membrane fuel cell is the endplate, which must exert uniform contact pressure distribution on the membrane electrode assembly. Since the endplates must be highly rigid, it is essential to consider the flexural modulus parameter when designing these plates. In this study, the production of lighter-weight endplates with a higher flexural modulus is significantly improved by replacing heavy metallic plates with polymer composite plates. The vacuum bag manufacturing technique was used to create these composite plates from epoxy resin, carbon fibers, and glass fibers, making them compatible with the environment of the fuel cell. The flexural modulus and heat deflection temperature of each sample were evaluated before and after a simulated environment test of the fuel cell. Then, the amount of water absorption for each specimen was calculated. Finally, the composite endplates were fabricated using the two different laminations of fibers to find the optimum fiber lamination to maximize the endplate flexural rigidity. The optimum sample contained carbon fibers with an epoxy resin with 0 degrees arrangement. This specimen has a flexural modulus of about 93.17 GPa, heat deflection temperature of about 261 °C, and water absorption of about 0.86%, which are ideal for fuel cell endplates.
Hydrogen, Fuel Cell & Energy Storage, 2022
Among direct alcohol fuel cells, the ethanol fuel cell is considered the most acceptable in terms... more Among direct alcohol fuel cells, the ethanol fuel cell is considered the most acceptable in terms of safety and power density. In this research, a Pt/CNFs-GNPs /GDL electrode was developed using GNPs and CNFs as a supporting medium on carbon paper and the electrodeposition method to deposit Pt catalyst. The morphology and structure features of the prepared film samples were characterized by FESEM and XRD. Pt particles of about 6.53 nm were uniformly deposited on the porous support. Catalytic activities of the prepared electrode for the ethanol oxidation reaction were evaluated through cyclic voltammetry measurements. Based on the electrochemical properties, the as-prepared Pt/CNFs-GNPs/GDL electrocatalyst exhibited a comparable activity for ethanol oxidation reaction for the Pt/C, which may be attributed to the high specific surface area of the CNFs support as well as high conductivity of graphene nanoplates. A notable reduction in the onset and peak potential of ethanol electro-oxidation from 0.55 and 0.81V for Pt/C/ GDL to 0.50 and 0.79V for Pt/CNFs-GNPs/GDL electrodes, as well as a substantial increment in anodic Tafel slope values from 376 mV to 521 mV, indicates that an increase in the activity for EOR is achieved by replacing C with CNFs-GNPs.
Hydrogen, Fuel Cell & Energy Storage, 2022
This study presents the energy, exergy, and economic evaluation of recovering energy from a modif... more This study presents the energy, exergy, and economic evaluation of recovering energy from a modified Kalina power-cooling system to provide heating and hydrogen. An ORC is employed to use the waste heat of the Kalina cycle, and the generated power is transmitted to a PEM electrolyzer for hydrogen production. Furthermore, the waste heat of the separator outlet is recovered through a new heat exchanger to provide heating. The results show that the proposed system can produce 317 kW power, 714.7 kW cooling, 50.3 kW heating, and 4.491 kg/h hydrogen. Moreover, the exergoeconomic analysis indicates that the PEM electrolyzer, the cascade heat exchanger, and the vapor generator have the highest cost rate among the system components. Additionally, a parametric study was performed on the system to investigate the variation of some key parameters, including the maximum operating pressure, separator II pressure, ammonia mass fraction in a basic solution, and pinch point temperature difference in the cascade heat exchanger for the thermodynamic and economic performance of the system.
Hydrogen, Fuel Cell & Energy Storage, 2022
A PEM fuel cell is considered a system with a complex mechanical structure due to a large number ... more A PEM fuel cell is considered a system with a complex mechanical structure due to a large number of components with different dimensions and materials. Understanding this structure is essential to design fuel cells against dynamic loads such as shock and vibration. In this paper, modal analysis of a 500 W fuel cell with an active area of 225 cm 2 has been performed. The fuel cell has been excited in transverse and longitudinal directions, and the outputs of the sensors were recorded at several points. Using the Poly reference least-squares complex frequency-domain method, the first ten transverse and longitudinal natural frequencies and mode shapes of the model were determined. Modal analysis revealed that the lack of structural integrity, the layered structure, and the layer connection type results in the formation of mode shapes that do not match conventional predictions. Comparison of the numerical and experimental results showed a maximum difference of 15%. Furthermore, the results illustrated that changing geometrical and mechanical properties of the membrane by 45% have a negligible effect on the natural frequency of the fuel cell. Allowing for this fact will result in a significant reduction in the computational cost of large-scale fuel cells analysis.
Hydrogen, Fuel Cell & Energy Storage, 2022
Liquid propellant missiles are commonly applied to launch satellites that must be located in uppe... more Liquid propellant missiles are commonly applied to launch satellites that must be located in upper orbits. These systems normally use hydrogen and oxygen propellants that are non-hypergolic mixtures. In this study, the test results of a designed hydrogen/oxygen engine were evaluated, and a designed spark igniter was successfully used to start the engine. Seven hot tests were carried out to determine the performance of the engine. The effect of oxygen to fuel ratio (O/F ratio) at a constant combustion chamber pressure (800 kPa) showed that the maximum value of the specific impulse (Isp) and characteristic velocity (C*) occurs at an O/F ratio of about 2.8. Experimental tests at the constant O/F ratio of 2.8 showed that performance parameters, such as Isp and C*, were enhanced when the chamber pressure was increased. However, the trend was sluggish at pressures higher than 800 kPa.
Hydrogen, Fuel Cell & Energy Storage, 2022
In this paper, the capability of the Computational Fluid Dynamics (CFD) approach to reliably pred... more In this paper, the capability of the Computational Fluid Dynamics (CFD) approach to reliably predict the fluid dynamic and the separation performance of Pd membranes modules for gas mixture separation is evaluated. In this approach, the flow fields of the pressure and velocity for the gas mixture and the species concentration distribution in the selected three-dimensional domains are obtained by the simultaneous, numerical solution of continuity, momentum, and species transport (especially, the gas-through-gas diffusion term derived from the Stefan-Maxwell formulation) equations. Therefore, the calculation of the hydrogen permeation depends on the local determination of the mass transfer resistance caused by the gas phase and membrane, which is modeled as a permeable surface of known characteristics. The applicability of the model to properly predict the separation process under a wide range of pressures, feed flow rates, temperatures, and gas mixtures compositions is assessed through a strict comparison with experimental data. Moreover, in this work, the influence of the inhibitor species on the module performance, which is obtained by implementing the CFD model, is discussed. The results of the simulation showed that increasing the pressure on the feed side increases the molar fraction of hydrogen gas and the feed inlet flow on the shell side, and the hydrogen permeation through the membrane in the tube side. Comparison of simulation results with laboratory data showed good agreement. The model was obtained with an error of less than 3% at 450K and below 6% for 475K and 500K.
Hydrogen, Fuel Cell & Energy Storage, 2022
In this study, the plastic deformation of a metallic bipolar plate with a serpentine flow field w... more In this study, the plastic deformation of a metallic bipolar plate with a serpentine flow field was investigated during the stamping process. The strain path and thickness distribution in 304 stainless steel bipolar plates with a thickness of 0.1 mm were determined. To achieve this purpose, the process was simulated by the ABAQUS commercial finite element code, and the validity of the results was evaluated by experimental tests under simple and lubricated conditions. According to the results, the flow of material has a significant effect on the thickness distribution of the central and lateral channels, and the thickness reduction percentage of the central channel in the longitudinal, diagonal, and transverse directions is higher than the lateral one. The maximum thickness reduction in the central channels is observed in the longitudinal direction, while the diagonal direction is considered as a critical direction for lateral channels. Due to the existence of the equibiaxial tension strain path in the diagonal direction, significant thickness reduction is observed in both the side and the rib zone of the channels. However, using lubricant led to a decrease in the thickness reduction percentage by improving the flow of material into the die cavity. Moreover, under lubricated conditions, the critical area is transferred from the side area of the channel in the longitudinal direction to the rib area in the diagonal direction
Hydrogen, Fuel Cell & Energy Storage, 2021
PEM Fuel cell ORC waste heat recovery hybrid PEMFC/GT One of the most important methods for effic... more PEM Fuel cell ORC waste heat recovery hybrid PEMFC/GT One of the most important methods for efficient hydrogen utilization is the proton exchange membrane fuel cell (PEMFC) because of its low environmental impact and easy maintenance. Depletion of fossil fuels along with global warming is all the more reason for researchers to seek new methods to convert primary energy into power, heating, etc. In the meantime, fuel cells are a promising method to convert energy into usable power. In this study, a proton exchange membrane fuel cell utilizing hydrogen as a fuel is proposed as the main component of a power generation system. The waste heat of the fuel cell is then recovered via two scenarios, using the waste heat as the heat source of an organic Rankin cycle (ORC) or using it to be expanded in the gas turbine. A comprehensive energy and exergy analysis are carried out to find the effectiveness of the system along with the adverse conditions of the components. Results demonstrate that at operation conditions, the system integrated with a gas turbine performs better in terms of energy and exergy efficiencies by 45% and 33%, respectively. Also, Fuel cell, and afterburner has the highest exergy destruction ranks amongst other elements, since they have all three main source of irreversibility. Furthermore, the economic study results show that the PEMFC/GT has a lower Levelized cost of electricity compared to the PEMFC/ORC.
Hydrogen, Fuel Cell & Energy Storage, 2021
A high porous three-dimensional structure of ternary NiPC alloy (3D-NiPC) was prepared with a sim... more A high porous three-dimensional structure of ternary NiPC alloy (3D-NiPC) was prepared with a simple, cheap, and efficient method called dynamic hydrogen bubble template (DHBT) and characterized by means of microstructural and electrochemical techniques with regard to its catalytic effect toward the hydrogen evolution reaction (HER) in an alkaline solution. The electrochemical efficiency of the alloy has been evaluated on the basis of electrochemical data obtained from the steady-state polarization Tafel curves and electrochemical impedance spectroscopy (EIS) in a 1 M NaOH solution at 298 K. The results showed that the three-dimensional structure of NiPC alloy effectively increased its catalytic activity toward the HER. The 3D-NiPC alloy is characterized by low overpotential at practical high current densities, large real surface area, and double-layer capacitance. Also, the 3D-NiPC showed very good physical and electrochemical stability. A high roughness factor (three orders of magnitude; R f =3550), low overpotential at 250 mAcm-2 (η 250 =173.3 mV), and low charge transfer resistance (R ct =100 Ωcm 2) were obtained in the best conditions, in 1 M NaOH at 298 K.
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Papers by Hydrogen, Fuel Cell & Energy Storage