A two-dimensional computational model of a loaded used nuclear fuel canister filled with helium gas was constructed to predict the cladding temperature during vacuum drying conditions. It includes distinct regions for the fuel pellets, cladding and helium within each basket opening. Symmetry boundary conditions are employed so that only one-eighth of the package cross-section is included, and t...

Hydrogen is seen as one of the important energy carriers of the future with potential to reduce local as well as global warming. The main by-product of the combustion of hydrogen in air is water vapor and trace quantities of oxides of nitrogen. An experiment was conducted to study the impact of hydrogen/natural gas blends on performance, thermodynamic efficiency and exhaust gas emissions in ...

As an alternative or supplement to small batteries, the much-anticipated micro-direct methanol fuel cell ( DMFC) faces several key technical issues such as methanol crossover, reactant delivery, and byproduct release. This paper addresses two of the issues, removal of CO2 bubbles and delivery ofmethanol fuel, in a non-prohibitiveway for systemminiaturization. A recently reported bubble-driven p...

Fuel cells are receiving widespread attention as an alternate source for clean energy, and one of the most important developments are proton-exchange membrane fuel cells (PEMFC) which operate using hydrogen at low temperatures. In the U.S., there is a considerable effort underway to develop H2 as the preferred fuel due to the potential for decreasing our dependence on imported oil, and the envi...

The purpose of this paper is to provide an expected cost comparison for operating a transit-bus fleet on three different alternative fuels-biodiesel, compressed natural gas (CNG), and methanol. Petroleum diesel is the base fuel. Infrastructure, refueling, and maintenance costs are all part of running an urban transit bus. Additional expenditures would be needed to change fuel storage and delive...

In this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (GDL) of PEM fuel cell is modeled. The governing equations including energy, mass and momentum conservation equations are solved by numerical methods. Also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (GDL) thickness and inlet relative humidity are calculated...

The dual fuel engines at part loads inevitably suffer from lower thermal efficiency and higher carbon monoxide and unburned fuel emission. This work is carried out to investigate combustion characteristics of a dual fuel (dieselgas) engine at part loads, using a single zone combustion model with detailed chemical kinetics for combustion of natural gas fuel. The authors developed software in ...

The usage of lean-burn engines is a promising strategy for improving the fuel economy of vehicles and reducing the emission of greenhouse gas CO2. The most complex challenge for leanburn engines is the need to find a solution for the increased levels of NOx emissions. Lean NOx trap (LNT) or NOx storage-reduction (NSR) catalysts provide a very effective method for NOx removal in lean-burn gasoli...

A fuel cell can be thought of as a cold-combustion power source that generates electrical energy directly from (stored) chemical energy. Due to minimal heat transfers, it is unfettered by conversion-efficiency limitations characteristic of hot-combustion devices. Unlike batteries, but similar to internal combustion engines, a fuel cell is a continuous-flow system in which fuel and oxidant are e...

The paper presents an analysis on small systems for converting biomass/wastes into power using Micro Gas Turbines (MGT) fed with gaseous bio-fuels produced by airgasification. The MGT is designed for burning various fossil liquid and gas fuels, having catalogue data related to natural gas use. Fuel switch changes their performances. The present work is focused on adapting the MGT for burning al...