P14254: Underwater Thermoelectric Power Generation
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MSD1

Table of Contents

This page contains a summary of the Senior Design I process with links to detailed pages about the design

Problem

Background

The project scope was defined by the PRP (Word). The goal of the project is to create an underwater thermoelectric generator system that could be adapted to a Boeing unmanned underwater vehicle (UUV) to extend the range of the UUV.

Team Structure

The team members are Charles Alexander (Mechanical Engineer), Tom Christen (ME), Kim Maier (ME), Reggie Pierce (ME), Matt Fister (Electrical Engineer), and Zach Mink (EE). Kim was designated Project Manager and Tom, Lead Engineer. As a team, we agreed upon a set of norms and values.

Problem Definition

After a few meetings with Dr. Rob Stevens (the acting customer) and a phone conversation with Kevin Meredith (a Boeing representative), we settled on a formal problem definition and developed requirements. This was concluded by a problem definition review.

System Design

The system design process was started by completing our engineering requirements (PDF) with specification limits. A functional decomposition and Benchmarking & Research established focus areas.

Concepts

Using the information collected from benchmarking and functional decomposition, we developed system concepts and selected a Systems Design.

See also: Systems Design Review

Design

The final design consists of a mechanical system which generates power underwater connected to an electrical system which charges the battery and a computer based data acquisition system, both of which are out of the water.

The mechanical system is basically a heat sink onto which thermoelectrics and a heater are clamped along with thermocouple sensors. The system is covered by a commercial IP68 enclosure and connected to the (above-water) electronics by a liquid-tight electrical conduit. An electrical resistance heater will supply 563W of heat, of which approximately 20W will be lost through the insulation, the rest will be converted to 19.8W of electrical power by three thermoelectric modules. Detailed drawings of mechanical components can be found here.

The electrical system consists of a ZETA converter controlled by an Atmel ATTiny microcontroller which together function as a maximum power point tracker for the thermoelectrics and will charge a 55Whr lithium ion battery. The controller will monitor the battery state to ensure safe charging, and an electronic load will serve to discharge the battery.

Manufacturing and assembly plans have been completed for the mechanical and electrical systems. The manufacturing process will proceed in parallel with the testing process to ensure rapid diagnosis of problems.

Final Design

Bill of Materials

Detailed Drawings