| Summary: | 碩士 === 元智大學 === 機械工程學系 === 98 === The electric thermos is a very common home appliance in every family. If there are methods to improve its thermal insulation by using a cheap and simple structure in the electric thermos, they will provide many benefits to the personal life and the environmental protection. This research aims to apply the fundamental principles of heat transfer to reduce the total heat loss from the thermos, and estimates the related heat losses.
Two different materials, aluminum foil and the honeycomb paper, will be used in the experiments to enhance the insulation. With the aluminum foil and the honeycomb paper, the heat loss due to radiative and convective heat transfer can be reduced. In the 24-hour test, the power consumption is found to decrease about 15% by attaching an aluminum foil on the wall of the inside housing of the electric thermos.
The optimal insulation in these modifications is to place the aluminum foil 1cm close to the water tank and to block the gap between the aluminum foil and the housing. The results also show that the honeycomb paper is a great improvement for the convection heat loss, but when the air between the housing and the water tank is almost stagnant, it will cause reverse effect on the corresponding thermal insulation.
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