Date of Award

Fall 2001

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)


Mechanical Engineering

First Advisor

Dunbar, William R.

Second Advisor

Gaggioli, Richard A.

Third Advisor

Park, Hyunjae


The increasing trend of fuel energy conversion and the quick consumption of nonrenewable fuels such as natural gas have been the motivating factors of this work. Several more efficient energy systems have been developed to help alleviate the natural source consumption and environmental impacts. The incorporation of several system components such as fuel cell, Direct Contact Water Heater, Jet Pump, Heat Pump, and steam turbine have been employed to increase the "conceivable" energy systems overall performance. Different combinations of them and different ways to integrate them have improved the "conventional" energy systems (boiler). If the reader has little interest on economic and environmental issues, it is suggested that the reader skip Chapters 2 and 3 and proceed to Chapters 4, 5, and 6 which covers the engineering issues. In Chapter 2, historical data of fuel energy conversion is presented, and the existing problem of "Electrical Energy Losses" is revealed. In Chapter 3, several economic models are presented to reveal the trend of fuel energy conversion in a more mathematical way. Environmental impacts are also presented to prove the urgency of slow down fuel consumption. In Chapter 4, system simulation and analysis techniques employed in this work are presented. It needs to be emphasized that a proper evaluation of an energy system performance requires not only First Law analysis but also Second Law analysis, which has been shown through past literature and research work. By doing so, two "conventional" energy systems are modeled and analyzed. The existing problems related to mismatch between "source" (fuel) and "receiver", "Electrical Energy Losses", fuel savings, heat transfer surface area within the boiler are discussed. To solve these problems, Chapter 6 presents twelve alternate, "conceivable" energy systems. By employing Direct Contact Water Heater, "conceivable" energy systems try to achieve the system performance limit in the view of First Law analysis. In the other way, fuel cells are employed to decrease the irreversibilities associated with the uncontrolled combustion and heat transfer processes within the conventional boiler. The modeling and simulation of individual system components is also presented in Chapter 6. The research work presented in this thesis is made based on both existing technology and assumptions. Some assumptions, even not currently practical, still point out some topics for future research work. Incorporating the research ideas of this work, more system components and new energy conversion technologies are going to be explored to develop the next-generation energy systems.



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