Cooking up a solution to microwave heat distribution

Hydrogen is one of the modern energy carriers, but its storage and practical use of the newest hydrogen technologies in real operation conditions still is a task of future investigations. This work describes the experimental hydrogen hybrid energy system (HHS). HHS is part of a laboratory off-grid system that stores electricity gained from photovoltaic panels (PVs). This system includes hydrogen production and storage units and NEXA Ballard low-temperature proton-exchange membrane fuel cell (PEMFC). Fuel cell (FC) loses a significant part of heat during converting chemical energy into electricity. The main purpose of the study was to explore the heat distribution phenomena across the FC NEXA Ballard stack during load with the next heat transfer optimization. The operation of the FC with insufficient cooling can lead to its overheating or even cell destruction. The cause of this undesirable state is studied with the help of infrared thermography and computational fluid dynamics (CFD) modeling with heat transfer simulation across the stack. The distribution of heat in the stack under various loads was studied, and local points of overheating were determined. Based on the obtained data of the cooling air streamlines and velocity profiles, few ways of the heat distribution optimization along the stack were proposed. This optimization was achieved by changing the original shape of the FC cooling duct. The stable condition of the FC stack at constant load was determined.

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Microwave Energy Pretreated In Situ Transesterification of Jatropha Curcas L in the Presence of Phase Transfer Catalyst

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.625.267 ◽

2014 ◽

Vol 625 ◽

pp. 267-270 ◽

Cited By ~ 1

Author(s):

Sintayehu Mekuria Hailegiorgis ◽

Mahadzir Shuhaimi ◽

Duvvuri Subbarao

Keyword(s):

Statistical Model ◽

Jatropha Curcas ◽

Phase Transfer ◽

Phase Transfer Catalyst ◽

In Situ Transesterification ◽

Heat Pretreatment ◽

Seed Particles ◽

Optimum Reaction ◽

Microwave Heat

In the present work, microwave heat pretreatment of jatropha curcas seed particles and use of phase transfer catalyst (PTC) to enhance in-situ transesterification were utilized together. It was observed that use of alkaline BTMAOH as a PTC and microwave heat pretreatment of jatropha curcas seed particles had substantially increased the reaction rate of in-situ transesterification as compared to the reaction conducted with microwave untreated seeds in the absence of BTMAOH as a PTC. Statistical model equation was developed to investigate the interaction effect of reaction variables and establish optimum reaction condition. At optimum condition, experimentally obtained FAME yield (93.7±1.53% w/w) was in close agreement with statistical model predicted FAME yield (96.75%) at 38°C and 37 minutes of reaction time.

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Complex mathematical model for computer calculation of delivery and heat distribution in pipeline system

Proceedings of the 6th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems ◽

10.1109/idaacs.2011.6072828 ◽

2011 ◽

Cited By ~ 1

Author(s):

I. V. Baranova ◽

Y. V. Parfenenko ◽

V. G. Nenja

Keyword(s):

Mathematical Model ◽

Computer Calculation ◽

Pipeline System ◽

Heat Distribution ◽

Complex Mathematical Model

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Simulation of Heat Stress and Fatigue on Engine Case

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.397-400.413 ◽

2013 ◽

Vol 397-400 ◽

pp. 413-417

Author(s):

Chang Hui Hou ◽

Hong Li Fan ◽

Qian Sang ◽

Ji Ping Lu

Keyword(s):

Heat Stress ◽

Fatigue Life ◽

Working Conditions ◽

Research Result ◽

High Stress ◽

Heat Distribution ◽

Transient Stress ◽

Working Stress ◽

Maximal Stress ◽

Safe Working

In this paper, a model of an engine case is designed in Pro/Engineer for fatigue simulation. The meshing is created by the way of Abaqus. According to the working conditions, the boundary restriction of the simulation is defined. By the simulation, the heat distribution of the engine case is given, the causes of relatively high temperature areas are discussed, and the heat-stress distribution is drawn too. The high stress area in the engine case is discovered. The simulation result shows that the steady working stress is about 60MPa, the transient stress is between 90MPa to 120MPa, and the maximal stress is 136MPa. Based on the heat stress the fatigue life of the engine case is analyzed. The research result is a reference of the engine case safe working.

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