Assumptions
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To make the calculations which need to be performed necessarily simple, several assumptions need to be made as to the nature of the system.
- This is not a closed system, there will be energy flow from one part of the system to the next, with the temperature gradient of the system returning to 0 at time = infinity.
- The external surface of the system is a uniform rectangular prism
with dimensions of 7m X 1.93m X 2.44m , the approximate size of a small
shuttle bus. (1)
- The system has complete, standard over-the-counter fiberglass
insulation with a metric R value of 3.52 m2K/W. (2)
- All liquid and air convection effects are complete and do not have to be accounted for.
- Heat is transferred uniformly through the systems components.
- The majority of operational time for the block will be at just above the melting point of the pariffin in order to take full advantage of the high specific heat of fusion for that material.
- The charging of the thermal reservoir will not be accounted for. The heat transfer will begin after the reservoir is fully charged.
- The system contains only the reservoir and the
rectangular prism. There are no areas without insulation.
- The adapter will have a surface area, but will have a negligible volume and mass, and will have an R value of essentially 0 m2K/W.
- Coefficient will be approximate, and given the nature of paraffin, which can vary in molar mass from 16g/mol to 560g/mol, this seems appropriate.
- Volume effects due to thermal expansion will not be taken into account.
- The thermal block will only be
conducting out of the top surface, due to the practicality of only one
face showing.
