Date of Award

Summer 1998

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)


Mechanical and Industrial Engineering

First Advisor

Gaggioli, Richard A.

Second Advisor

Dunbar, William R.

Third Advisor

Sekulic, D. P.


The simulation of energy systems is an effective way of predicting the performance of the system without actually constructing the system. With memory and processor speed improvements on personal computers, the study of energy systems by computer simulation is more practical now than it has been in the past. One industry more concerned with system performance than ever before is the refrigeration industry. Due to environmental concerns and regulations it is often not economically feasible to keep an existing system operating in its current condition. Therefore, many refrigeration systems are undergoing changes in hardware components, the system's working fluid(s) or both. These systems are candidates for either replacement of retrofit. Computer simulations of the system's performance after retrofit can offer valuable insight comparing retrofit costs (both capital and operating) to replacement costs. The implementation of an energy system simulation involves the development of both mathematical models for hardware components and a thermophysical property library of the fluids involved in the system. This thesis attempts to aid the engineer that may be new and unfamiliar with the simulation of energy systems by investigating the methodology for the development of a thermophysical property library, as well as the development of a mathematical model for the overall performance of an existing hardware component, specifically a positive displacement compressor (a common hardware component of the refrigeration industry). Along with these relationships for thermophysical properties and overall compressor performance this thesis also addresses the development of mathematical models for simulation overall system performance, under variable load conditions. This simulation, though, employs simplistic, provisional models for the other components of a refrigeration system, namely the heat exchangers and expansion valve. Included are the Mathematica notebooks used to develop and implement the thermophysical property library as well as the system simulation components and program. It is the hope of the author, that the notebooks will serve not only as functioning tools, but also as a demonstration of the power that Mathematica possesses for handling the problems that energy system problem solving and energy system simulation may present.



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