Development of Pem Fuel Cell in Pakistan

2009 ◽  
Vol 20 (4) ◽  
pp. 597-604 ◽  
Author(s):  
R. Raza ◽  
S. A. Hayat ◽  
M. Ashraf Chaudhry ◽  
J. Muhammad

There is a worldwide awareness for finding alternate energy sources. Fuel cells are seen as potential candidates to fill the upcoming energy shortage gap. In line with this global approach, an initiative has been undertaken for developing Fuel Cells in Pakistan. Accordingly, a prototype Fuel Cell was developed. Different experiments were conducted to gauge its performance. The results are presented in the graphical form. The study has also been extended to measure the impact of catalyst on various performance determining parameters of the Fuel Cell.

2021 ◽  
Author(s):  
Jianghui Yin

A detailed non-isothermal computational fluid dynamics (CFD) model for proton electrolyte membrane (PEM) fuel cells is developed in this thesis. This model consists of the equations of continuity, momentum, energy, species concentrations, and electric potentials in different regions of a PEM fuel cell. In particular, the fairly thin catalyst layers of the fuel cell are assigned a finite thickness instead of being treated as nil thickness interfaces in other PEM fuel cell models. Various source/sink terms are presented to associate the conservation equations with the electrochemical reaction kinetics. The water balance in the membrane is modeled by coupling diffusion of water, pressure variation, and the electro-osmotic drag. The membrane swelling effect is explicitly considered the newly derived model, leading to a set of novel water and proton transport equations for a membrane under the partial hydration condition. The electron transport in the catalyst layers, gas diffusion layers and bipolar plates are also described. The PEM fuel cell model developed has been implemented into a commercial CFD software package for simulating various flow and transport phenomena arising in operational PEM fuel cells, analyzing the impact of design and operating parameters on the cell performance, and optimizing the PEM fuel cell design.


2021 ◽  
Author(s):  
Jianghui Yin

A detailed non-isothermal computational fluid dynamics (CFD) model for proton electrolyte membrane (PEM) fuel cells is developed in this thesis. This model consists of the equations of continuity, momentum, energy, species concentrations, and electric potentials in different regions of a PEM fuel cell. In particular, the fairly thin catalyst layers of the fuel cell are assigned a finite thickness instead of being treated as nil thickness interfaces in other PEM fuel cell models. Various source/sink terms are presented to associate the conservation equations with the electrochemical reaction kinetics. The water balance in the membrane is modeled by coupling diffusion of water, pressure variation, and the electro-osmotic drag. The membrane swelling effect is explicitly considered the newly derived model, leading to a set of novel water and proton transport equations for a membrane under the partial hydration condition. The electron transport in the catalyst layers, gas diffusion layers and bipolar plates are also described. The PEM fuel cell model developed has been implemented into a commercial CFD software package for simulating various flow and transport phenomena arising in operational PEM fuel cells, analyzing the impact of design and operating parameters on the cell performance, and optimizing the PEM fuel cell design.


Author(s):  
Praveen Narasimhamurthy ◽  
Zakiul Kabir

UTC Fuel Cells (UTCFC) over the last few years has partnered with leading automotive and bus companies and developed Polymer Electrolyte Membrane (PEM) fuel-cell power plants for various transportation applications, for instance, automotive, buses, and auxiliary power units (APUs). These units are deployed in various parts of the globe and have been gaining field experience under both real world and laboratory environments. The longest running UTC PEM fuel cell stack in a public transport bus has accumulated over 1350 operating hours and 400 start-stop cycles. The longest running APU fuel cell stack has accrued over 3000 operating hours with more than 3200 start-stop cycles. UTCFC PEM fuel-cell systems are low noise and demonstrate excellent steady state, cyclic, and transient capabilities. These near ambient pressure, PEMFC systems operate at high electrical efficiencies at both low and rated power conditions.


2021 ◽  
Vol 66 (1) ◽  
pp. 1-13
Author(s):  
Wanyi Ng ◽  
Mrinalgouda Patil ◽  
Anubhav Datta

The objective of this paper is to study the impact of combining hydrogen fuel cells with lithium-ion batteries through an ideal power-sharing architecture to mitigate the poor range and endurance of battery powered electric vertical takeoff and landing (eVTOL) aircraft. The benefits of combining the two sources is first illustrated by a conceptual sizing of an electric tiltrotor for an urban air taxi mission of 75 mi cruise and 5 min hover. It is shown that an aircraft of 5000–6000 lb gross weight can carry a practical payload of 500 lb (two to three seats) with present levels of battery specific energy (150 Wh/kg) if only a battery–fuel cell hybrid power plant is used, combined in an ideal power-sharing manner, as long as high burst C-rate batteries are available (4–10 C). A power plant using batteries alone can carry less than half the payload; use of fuel cells alone cannot lift off the ground. Next, the operation of such a system is demonstrated using systematic hardware testing. The concepts of unregulated and regulated power-sharing architectures are described. A regulated architecture that can implement ideal power sharing is built up in a step-by-step manner. It is found only two switches and three DC-to-DC converters are necessary, and if placed appropriately, are sufficient to achieve the desired power flow. Finally, a simple power system model is developed, validated with test data and used to gain fundamental understanding of power sharing.


Author(s):  
Jeffrey S. Vipperman ◽  
A. Fatih Ayhan ◽  
William W. Clark ◽  
Jimmy D. Thornton ◽  
Randall S. Gemmen

A novel axial-flow piezoelectric microvalve for fuel cell applications has been designed and analyzed. Microvalves offer to improve flow maldistribution problems that have been identified in fuel cells. This paper will outline the design of an embeddable microvalve that has many novel features, including an axial flow characteristic, piezoelectric trimorph actuation mechanism, unlimited scalability, thermally-insensitive activation, and relative simplicity. Detailed electro-mechanical, thermal, and fluidic analyses of the design are conducted using ANSYS and MATLAB simulation packages. The valve geometry is heuristically optimized based upon the results of the analyses. Fabrication and testing of the valve is currently underway.


2015 ◽  
Vol 12 (1) ◽  
Author(s):  
A. Verma ◽  
R. Pitchumani

Polymer electrolyte membrane (PEM) fuel cells are well suited for automotive applications compared to other types of fuel cells owing to their faster transient response and low-temperature operation. Due to rapid change in loads during automotive applications, study of dynamic behavior is of paramount importance. This study focuses on elucidating the transient response of a PEM fuel cell for specified changes in operating parameters, namely, voltage, pressure, and stoichiometry at the cathode and the anode. Transient numerical simulations are carried out for a single-channel PEM fuel cell to illustrate the response of power as the operating parameters are subjected to specified changes. These parameters are also optimized with an objective to match the power requirements of an automotive drive cycle over a certain period of time.


2005 ◽  
Vol 2 (4) ◽  
pp. 226-233 ◽  
Author(s):  
Shaoduan Ou ◽  
Luke E. K. Achenie

Artificial neural network (ANN) approaches for modeling of proton exchange membrane (PEM) fuel cells have been investigated in this study. This type of data-driven approach is capable of inferring functional relationships among process variables (i.e., cell voltage, current density, feed concentration, airflow rate, etc.) in fuel cell systems. In our simulations, ANN models have shown to be accurate for modeling of fuel cell systems. Specifically, different approaches for ANN, including back-propagation feed-forward networks, and radial basis function networks, were considered. The back-propagation approach with the momentum term gave the best results. A study on the effect of Pt loading on the performance of a PEM fuel cell was conducted, and the simulated results show good agreement with the experimental data. Using the ANN model, an optimization model for determining optimal operating points of a PEM fuel cell has been developed. Results show the ability of the optimizer to capture the optimal operating point. The overall goal is to improve fuel cell system performance through numerical simulations and minimize the trial and error associated with laboratory experiments.


Author(s):  
David A. Berry ◽  
Robert James ◽  
Todd H. Gardner ◽  
Dushyant Shekhawat

The near-term commercial success for many fuel cell technologies will rely on their ability to utilize current infrastructure fuels. Several large ready-markets exist for fuel cell systems that utilize middle distillate petroleum fractions like diesel fuel. One particular application is diesel-based auxiliary power units (APU). Unfortunately, very little research and development has been devoted to this application. Ongoing research at the National Energy Technology Laboratory (NETL) and other organizations is trying to address this need. In order for a fuel cell to utilize diesel fuel, it must be reformed into a synthesis gas containing primarily hydrogen, carbon monoxide, carbon dioxide, steam and possibly methane. Because catalytic reforming of hydrocarbon fuels is conducted at the same relative operating temperatures of technologies like solid oxide fuel cells (800–1000°C) a high degree of thermal integration is possible. Unfortunately, carbon deposition and sulfur poisoning of catalysts in the reformer and fuel cell make system operation potentially complicated and costly. To help understand and quantify the impact of these issues on technology development and component, a number of systems analysis was conducted for a diesel-based fuel cell system. One particular system based on a hybrid combustor/reformer concept allowed for excellent utilization of available heat from the fuel cell and yielded an overall fuel to electric conversion efficiency of nearly 50%. This paper discusses its salient features and compares its characteristics to other possible system configurations.


2019 ◽  
Vol 30 (4) ◽  
pp. 2077-2097 ◽  
Author(s):  
Zhenxiao Chen ◽  
Derek Ingham ◽  
Mohammed Ismail ◽  
Lin Ma ◽  
Kevin J. Hughes ◽  
...  

Purpose The purpose of this paper is to investigate the effects of hydrogen humidity on the performance of air-breathing proton exchange membrane (PEM) fuel cells. Design/methodology/approach An efficient mathematical model for air-breathing PEM fuel cells has been built in MATLAB. The sensitivity of the fuel cell performance to the heat transfer coefficient is investigated first. The effect of hydrogen humidity is also studied. In addition, under different hydrogen humidities, the most appropriate thickness of the gas diffusion layer (GDL) is investigated. Findings The heat transfer coefficient dictates the performance limiting mode of the air-breathing PEM fuel cell, the modelled air-breathing fuel cell is limited by the dry-out of the membrane at high current densities. The performance of the fuel cell is mainly influenced by the hydrogen humidity. Besides, an optimal cathode GDL and relatively thinner anode GDL are favoured to achieve a good performance of the fuel cell. Practical implications The current study improves the understanding of the effect of the hydrogen humidity in air-breathing fuel cells and this new model can be used to investigate different component properties in real designs. Originality/value The hydrogen relative humidity and the GDL thickness can be controlled to improve the performance of air-breathing fuel cells.


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