Systems Analysis of Diesel Based Fuel Cells for Auxiliary Power Units

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.

Author(s):  
Shafini Mohd Shafie ◽  
A Harits Nu'man ◽  
Nik Nurul Anis Nik Yusuf

Due to the emerging development in the energy industry, the demand for electricity consumption has sharply increased for each country. Therefore, a new recovery of energy resources is needed in consequence of the decreasing dependency on conventional energy resources, while sustaining energy security in the aspect of energy supply and climate change issues. The fuel cell is one of the most potential resources to be explored in order to overcome the constraints of the current energy generation. The aim of this paper is to discuss the entire cycle of the fuel cell system. It is starting from biogas production up to the recent studies related to life cycle assessment on fuel cell studies. Most of the researchers focused on the technical part of fuel cells; however, a comprehensive environmental assessment is essential to fully recognize the impact of fuel cells. Furthermore, this conceptual paper provided an idea on understanding the concept of fuel cell and referred to recently published articles related to life cycle assessment. Hopefully, this study can provide the guideline in determining the future energy for this country, in order to be less dependent on the current resources of energy supply.


2003 ◽  
Vol 1842 (1) ◽  
pp. 118-126 ◽  
Author(s):  
Nicholas Lutsey ◽  
Christie-Joy Brodrick ◽  
Daniel Sperling ◽  
Harry A. Dwyer

Fuel cells are widely expected to replace internal combustion engines in vehicles. However, their high initial costs preclude their introduction into the mass market for some time. A new approach is needed that focuses on niche markets. The potential use of fuel cells in auxiliary power units (APUs) on board various types of automobiles and trucks— in luxury passenger automobiles, law enforcement vehicles, contractor trucks, specialized utility trucks, recreational vehicles, refrigerated trucks, and line-haul heavy-duty trucks—is explored. Power requirements, volume and weight targets, costs, market sizes, and potential benefits for several fuel cell technologies and fuels are analyzed. The attributes of market applications are matched with fuel cell attributes to assess the market potential of fuel-cell APUs. Although data are insufficient and more analysis is needed, several market applications apparently could play key roles in introducing fuel cell technologies to the transportation sector.


2005 ◽  
Vol 139 (1-2) ◽  
pp. 205-213 ◽  
Author(s):  
Francesco Baratto ◽  
Urmila M. Diwekar ◽  
Davide Manca

2001 ◽  
Author(s):  
Herbert H. Dobbs ◽  
Erik T. Kallio ◽  
James M. Pechacek

2008 ◽  
Vol 176 (1) ◽  
pp. 90-95 ◽  
Author(s):  
Zhenwei Wang ◽  
Jörg Oberste Berghaus ◽  
Sing Yick ◽  
Cyrille Decès-Petit ◽  
Wei Qu ◽  
...  

2006 ◽  
Vol 3 (4) ◽  
pp. 492-494 ◽  
Author(s):  
Sari Tasa ◽  
Teppo Aapro

Mobile device manufacturers would like to provide totally wireless solutions—including charging. Future multimedia devices need to have longer operation times as simultaneously they require more power. Device miniaturization leaves less volumetric space available also for the energy source. The energy density of the Li-ion batteries is high, and continuously developed, but not at the same speed as the demand from devices. Fuel cells can be one possible solution to power mobile devices without connection to the mains grid, but they will not fit to all use cases. The fuel cell system includes a core unit, fuel system, controls, and battery to level out peaks. The total energy efficiency is the sum of the performance of the whole system. The environmental performance of the fuel cell system cannot be determined yet. Regulatory and standardization work is on-going and driving the fuel cell technology development. The main target is in safety, which is very important aspect for energy technologies. The outcomes will also have an effect on efficiency, cost, design, and environmental performance. Proper water, thermal, airflow, and fuel management of the fuel cell system combined with mechanical durability and reliability are the crucial enablers for stable operation required from the integrated power source of a mobile device. Reliability must be on the same level as the reliability of the device the energy source is powering; this means years of continuous operation time. Typically, the end-users are not interested of the enabling technologies nor understand the usage limits. They are looking for easy to use devices to enhance their daily life. Fuel cell technology looks promising but there are many practical issues to be solved.


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.


2017 ◽  
Vol 4 ◽  
pp. 76-86 ◽  
Author(s):  
Reece Cohen Woodley ◽  
Kane Yang ◽  
Geoffrey Bruce Tanner ◽  
Dennis Tran

This meta-study focuses on the research regarding the use of nanotechnology in traditional fuel cells in order to increase thermodynamic efficiency through the exploitation of various thermodynamic systems and theories. The use of nanofilters and nano-structured catalysts improve the fuel cell system through the means of filtering molecules from protons and electrons significantly increases the possible output of the fuel cell and the use of nano-platinum catalysts to lower the activation energy of the fuel cell chemical reaction a notable amount resulting in a more efficient system and smaller entropy in comparison to the use of macro sized catalysts.


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