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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

NUMERICAL DESIGN OPTIMIZATION FOR THERMAL AND PRESSURE BEHAVIOUR OF MULTIPLE CURVED CHANNEL COOLING PLATES IN ELECTRIC-VEHICLE BATTERY COOLING SYSTEMS

Banks, Benjamin 28 September 2012 (has links)
The effects of climate change along with shifts in social demands have opened up commercial possibilities for new and innovative green technology. At the head of this trend is research into new technologies for Hybrid Electric Vehicles (HEVs) and Battery Electric Vehicles (BEVs). These technologies would provide for more environmentally friendly transportation; however their current performance when compared to Internal Combustion Engine (ICE) Vehicles has led to slow adoption rates. One of the key factors that could help to increase the performance of HEVs and BEVs lies in improvement of the battery systems. Through proper thermal management of the batteries the range and performance of these vehicles can be improved, helping to increase the performance of the vehicles. This study looks at improving the thermal management of the battery system by generating more efficient cooling plates. These cooling plates are set between battery cells and contain channels that coolant is pumped through. Through optimization of these cooling channels, the efficiency of the cooling plates with regards to the average temperature and standard deviation of temperature of the battery cell can both be increased. The power required to run the cooling system can also be reduced by reducing the pressure losses associated with the cooling plate. Numerical optimization on three models of cooling plates was performed. The models were based on multi-inlet and outlet curved channel systems, with one model constructed using arcs and the other two using 90 degree angles. Results showed that improvements of up to 80% could be made depending on the objective functions when compared to an initial design through optimization, with straight channels providing 8% more efficient designs in terms of pressure losses over curved designs, and curved designs providing 6% more efficient designs in terms of average temperature. Analysis on the effects of varying the mass flow rate, heat flux and inlet temperature was also conducted to evaluate their effects on the optimized geometries. This study has practical applications in helping to develop new cooling plates for commercial use through implementation of the generated design features and optimization algorithms. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-09-27 15:09:12.261
2

Multi-Objective Design Optimization of Electric Vehicle Battery Cooling Plates Considering Thermal and Pressure Objective Functions

Jarrett, Anthony 07 September 2011 (has links)
The current stimuli of climate change and rising oil prices have spurred the development of hybrid electric (HEV), and battery electric vehicles (BEV): collectively termed EVs. However, the battery technology needs much development: at the time of writing, the range of a BEV is too low to be practical in many situations. A critical limitation is the sensitivity of batteries to temperature: the heat generated during operation affects their performance and reduces the lifetime. This study investigates battery cooling using cooling plates: thin rectangular fabrications inserted between battery cells. A coolant pumped through internal channels absorbs heat and transports it away from the battery. Previous studies of liquid heat exchangers have indicated that the geometry of the channels plays a significant role in the performance; however, there is a lack of rigorous numerical optimization applied to EV cooling plates. By developing a numerical optimization framework utilizing parametric geometry generation and computational fluid dynamics, this research has investigated the characteristics of optimum cooling plate geometry with respect to three objectives: average temperature, temperature uniformity, and coolant pressure drop. By applying each objective separately, improvements of up to 70% have been made compared to a reference design. The influence of boundary conditions on performance and optimum design has been assessed, and multi-objective optimization has investigated the trade-off between competing objective functions. Although care should be taken when extrapolating the results beyond the geometry and conditions in the study, some general design principles can be proposed. Objectives of average temperature and pressure drop can both be satisfied by a common design with wide cooling channels, but different characteristics are needed for temperature uniformity. Additional assessments have revealed that optimizations of temperature uniformity are especially sensitive to the boundary conditions, whereas the other objective functions are largely insensitive. The optimization process developed in this work can be applied to any potential cooling plate design and will lead to gains in the targeted performance measure. In doing so, the performance of the EV will be incrementally improved, thereby advancing the day when an EV is not only an environmental choice, but also a practical choice. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2011-09-07 16:24:14.6
3

Ventilace tlakové obálky reaktoru GFR / Heat transfer in the pressure cover of the GFR reactor

Koryčanský, Roman January 2014 (has links)
This paper describes the design of the ventilation pressure cover of the demonstrator GFR. The first part is a brief research project GFR and the effects of temperature on the inside structures. In the following part is calculated balance heat losses within the pressure cover for three cases: non-insulated, fully-insulated and partially insulated surface of the reactor. The following is a design of a heat sink for partially insulated surface.

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