P07441: Thermo-Electric Module Test Stand
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Thermo-Electric Module Test Stand

The creation of this project was motivated by Dr. Robert Stevens' interest in microscale heat transfer, and Mechanical Engineering Department's desire to develop and cultivate internal talent with regards to thermoelectric technology. Thermoelectric technology is not new; however, the field has received relatively less research exposure compared to related concentrations in Mechanical Engineering. Most existing research in this area is related to rating the performance of materials used in thermoelectric modules, engineering new thermoelectric materials, or testing individual modules. This project is interested in creating a thermoelectric test stand to reliably and fully characterize the performance of 10 commercially available thermoelectric modules. This means the performance of each module will be measured and compared over their operating range. Additionally, the construction of the test stand will be fully documented and will be used as reference material by future senior design teams, for forthcoming projects in this family.

Team Members

Team
Team Member Discipline Role / Skills Email Address
Dr. Robert Stevens ME Faculty Guide rjseme@rit.edu
Crisson Jno-Charles ME Project Manager caj6487@rit.edu
Clement Henry ME Structural analysis, Engineering drafting documents cah6988@rit.edu
Erik Herrman EE Data Acquisition, LabVIEW ejh3094@rit.edu
Emil Sandoz-Rosado ME Controls ejs2319@rit.edu
Kevin Smith ME Thermofluids modeling and analysis kds4040@rit.edu

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 Roles & Responsibilities

Planning

A Project Readiness Package has been prepared prior to the launch of this project. This PRP is intended to help get the team started with a first draft needs assessment and work breakdown structure.

Team Documents

This outline for the posting of team created documents follows the general product development process presented in the textbook Product Design and Development by Ulrich and Eppinger.

Senior Design I

Senior Design II

Concept Development

These links provide a basic starting point for your team to prepare a comprehensive web site about your project.

Identify Customer Needs

Establish Target Specifications

Generate Product Concepts

Select Product Concept(s)

System Level Design

 Thermoelectric test stand without insulation & mesh isolation

Thermoelectric test stand without insulation & mesh isolation

 Thermoelectric test stand without insulation, but including mesh isolation

Thermoelectric test stand without insulation, but including mesh isolation

The thermoelectric test stand will feature a wire-mesh insulation around the main structure to isolate users and bystanders from the test stand while it operates. Beyond mitigating burn injuries and combustion, the mesh also serves to improve the repeatability of each test by restricting access to the test stand (and therefore ensuring consistent test conditions), in addition to protecting the test chamber from large particulate.

Detail Design

The system's design was slightly modified after the Design Review to incorporate suggestions from the panel and correct mistakes. The team entered the Design Review with a cooling system requiring a connection to the RIT water system. An electrically controlled valve metered the amount of water flowing through the cooling system. The flow rate of the water was deemed to be high enough to provide adequate cooling for the anticipated heat load; however, the panel indicated that relying upon an electrically controlled valve would not provide sufficient control over the cooling system's temperature.

With this being the case, the team reverted to an older, more complicated idea of including a tank-fed pump controlling water circulating through the cooling system. Heat would be dissipated through a radiator attached to the cooling system. While this solution increases the cost of this part of the project, it also significantly increases controllability and repeatability.

Manufacturing & Assembly

The test stand will be manufactured over the following 8 weeks of Senior Design II. The test stand assembly is separated into three related sections: structural and mechanical assembly, electrical components and system controls, and LabVIEW data acquisition and software control. Each stage will progress concurrently with different team members sharing responsibility within each section.

Return to this section over the coming weeks for manufacturing logs and pictures of team progress.

Manufacturing Log

Pictures of the final test stand are displayed below:

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Testing and Refinement

The test stand and the software controlling its operation underwent significant refinement throughout the previous two months.

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The temperature controllers purchased were able to communicate with our DAQ through an unofficial drive provided by a third party. Through experimentation, the controllers were verified to work as expected. When the temperature controllers were interconnected with the 120V power controllers and supporting electronics (thermocouples), we verified that they could in fact control the temperature at the embedded thermocouple to a satisfactory level of certainty. While the temperature controller produced a steady state condition within the heating block relatively quickly, it did so by undershooting the set point temperature by a non-trivial degree. Autotunning the controller rectified this problem and brings the steady state temperature within an acceptable percentage of the set point temperature in a reasonable amount of time.

The DAQ system experienced significant development throughout the previous two months. The GUI for the DAQ was changed to separate different types of information, incorporating separate configuration, graphical display, and parameter output tabs. The result is a much more intuitive organization. The DAQ provides information about the temperature at various points within the heating block, the temperature of the cold plate, and current and voltage output produced from the thermoelectric generators. Additionally, safety parameters such as a maximum safety temperature are visually represented.

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Performance Curves

Future Improvements