Date of Award
Fall 2014
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Mechanical Engineering
First Advisor
Mathison, Margaret
Second Advisor
Bowman, Anthony
Third Advisor
Allen, Casey
Abstract
Nationwide process heating in the manufacturing sector accounts for 7,815 trillion BTU of energy use annually; this is roughly one-third of the sector's total energy consumption [Energetics Incorporated, 2014]. The U.S. Department of Energy estimates that seventy percent of process heating is fueled by the onsite burning of fossil fuels [Energetics Incorporated, 2014]. These fuel-fired process heating applications are prime opportunities for heat recovery projects capable of saving energy and, consequently, reducing operating costs. This thesis evaluates different methods for heat recovery in the Milwaukee manufacturing facility of STRATTEC Security Corporation. As a basis for this work, the overall energy usage of the facility is evaluated and the largest process heating and cooling loads are identified. Systems that will be evaluated include the zinc melt furnace, the low pressure steam system and the chilled water system. The energy recovered can be used to improve the efficiency of the source piece of equipment, to meet other process heating needs in the facility, or to generate electricity. These systems also can benefit from receiving energy recovered from a power generating process. Models of the energy and exergy balances in these systems are developed to predict the potential reduction in operating costs when heat recovery is implemented in the STRATTEC facility. In addition, the models and energy use information are used to identify inefficiencies in the systems that should be addressed before heat recovery is applied. Finally, a thermo-economic analysis is used to compare the various heat recovery options and select the most cost effective plan for implementing heat recovery. This analysis found that, for the existing equipment, heat recovery could not be implemented economically. However, opportunities for cost savings exist in the selection of new equipment to replace aging systems. Specifically, it was found that heat recovery could be implemented economically by replacing the existing chiller with an absorption chiller system that used waste heat from a power generation system.