Build, Test, Document
Table of Contents
The build, test, and document phase of the conductive heat transfer apparatus project includes the entirety of MSDII project activities. This section shall include documents related to the planning, redesigning, building, testing, and final product documentation for the fall semester 2013.
PlanningA project schedule was developed in the first weeks of MSDII. The chart below shows the original schedule and the actual time frame of task completion. The blue squares show the original project schedule, while the red squares show actual completion; overlap is shown in purple.
Early MSDII Issues
Cold Side Addition:
It was anticipated based on feedback from the detailed design review that the heavy cold side piping could cause torque on the specimen causing misalignment of thermocouples or other testing components. Therefore, time was dedicated to developing backup countermeasures. However, in testing, it was determined that no action was necessary.
Most materials had a reasonable lead time from suppliers, however, cartridge heaters were on backorder therefore the thermocouples and heater took over a month to arrive. Since both of these pieces were critical to testing, the lead time disrupted the original project schedule leading to the amended schedule above.
The sheet of rigid calcium silicate insulation originally designed to support and thermally insulate the length of the specimen arrived damaged from the supplier. Time used to ship the material back also caused project delays. As there was a possibility of the sheet coming damaged again and the incident revealed the potential brittleness of the material, modifications were made to the design to avoid complications.
Most of the length of the apparatus that was originally designed to be rigid calcium silicate insulation has been replaced by a protected air pocket. Structured mineral wool insulation covered by high temperature silicon fabric lines the inside of the wooden box. The cartridge heater "hot side" is supported by a smaller block of machined calcium silicate. Finally, the insulation is no longer used as a lip to seal the apparatus, but rather a hinge has been installed for easy assembly.
|Final Apparatus Design||Left: Hot Side, Right: Cold Side|
The system is designed to interact with a LabView interface that shows the temperature readout for each of the four thermocouples over time. As the four transient temperature lines begin to flatten and level out, the system has reached steady state.
At that point, the data can be exported to an Excel spreadsheet that is programmed with VBA to generate relevant information and graphs to analyze the conductive heat transfer data. The programmed VBA Excel file can be downloaded from the Final Documentation section below.
Component and apparatus testing plans and procedures are outlined in the Test Plan. Results and raw data from this testing can be found in the senior design testing data sheet. Key results are displayed below:
Each thermocouple was tested for repeatability of measurement by taking ten measurements of boiling water. Average measured temperatures and standard deviation of trials is shown in the chart.
A power curve was generated for the power supply in order to quantify heat input from the cartridge heater. The specific procedure and raw data can be found in the test plan and results data sheet. The data was then fit to an equation as shown below.
The following chart is a summary of overall apparatus testing results including steady state times and accuracy results.