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Jung, Hee-Suk;Eom, Chang-Deuk;So, Bum-Joon
- Journal of the Korean Wood Science and Technology
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- v.32 no.4
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- pp.18-26
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- 2004
Timbers of 14 by 14 cm, 2.4 m long, were dried in a vacuum kiln to investigate vacuum drying characteristics using three types of heating methods, conduction heating with hot plate, the radio frequency (RF) heating and the combination of both (hybrid heating). Average drying rate is the highest for the hybrid heating and the lowest for the RF heating. Average specific energy is the highest for the RF heating and the lowest for conduction heating. Transverse moisture content distribution of dried timber revealed the convex profile for both conduction and the hybrid heating and moisture content increased from one face to the opposite face for the RF heating. Moisture content distribution along the length of timber increased from the end to the middle of timber length for conduction and the hybrid heating and decreased from the end to the middle of timber length for the RF heating. End- and surface checks for conduction heating were severer than the other heating methods. No internal check occurred in any heating methods. Drying characteristics of conduction heating showed in-between trend of the RF and the hybrid heating.
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Kim, Sung-Bum;Oh, Byung-Chil;Shin, U-Cheul
- Journal of the Korean Solar Energy Society
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- v.36 no.6
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- pp.61-69
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- 2016
In this study, we analyzed five-year(2011~2015) data for D high school in Seoul area to analyze energy consumption characteristics in high school. The results are summarized as follows. (1) In the result of comparison analysis about 2015 energy consumption by usage, based on primary energy, 18% of energy was consumed in cafeteria, and 82% was consumed in main building. In the case of main building, base and constant load excepting hot water supply in restroom took 40%, heating including freeze protection took 20%, hot water supply in restroom took 14%, and cooling took 8% in order. (2) In the 2015 total energy consumption in D high school based on primary energy, heating energy takes 28%. The range and limit of energy savings coming from the reinforcement of insulation and window performance could be estimated. (3) To introduce new & renewable energy system in high school, electricity-based system is suitable than heat-based system because usage of electric energy is larger than that of heat energy in high school. (4) Five-year energy consumption unit according to heating degree-day showed a linearly increasing trend, and the coefficient of determination(R2) was 0.9763, which means high correlation.
https://doi.org/10.7836/kses.2016.36.6.061 인용 PDF KSCI