• Title/Summary/Keyword: GHP

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Effect of Greenhouse Cooling and Transplant Quality Using Geothermal Heat Pump System (지열-열펌프 시스템의 온실냉방 및 육묘 효과)

  • Lee, Jae-Han;Lee, Yong-Beom;Kwon, Joon-Kook;Kang, Nam-Jun;Kim, Hak-Joo;Choi, Young-Hah;Park, Jin-Myeon;Rhee, Han-Cheol
    • Journal of Bio-Environment Control
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    • v.15 no.3
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    • pp.211-216
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    • 2006
  • This study was carried out to investigate the effect of greenhouse cooling by a geothermal heat pump system on greenhouse temperature and growth of vegetable transplants in summer season. Greenhouse air temperature in day time was $3-4^{\circ}C$ lower in fog plus shading system than in shading, while in night time that was $5-7^{\circ}C$ lower in geothermal heat pump (GHP) plus shading system compared to shading or fogplus shading. system. Plant height of cucumber, tomato and hot pepper transplants was shortened in GHP plus shading compared to shading or fog plus shading system. And Leaf area and dry weight were slightly decreased in GHP plus shading compared to the other systems. Therefore, healthy transplant index on cucumber, tomato and hot pepper was higher in GHP plusshading than in shading or fogplusshading system.

The Economics of GHP and EHP and the Countermeasures to Alleviate Winter Electricity Peaks (GHP와 EHP의 경제성 및 동계 전력피크 대응방안)

  • Yun, Won-Cheol;Sonn, Yang-Hoon
    • Environmental and Resource Economics Review
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    • v.20 no.2
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    • pp.381-398
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    • 2011
  • Recently, electricity peaks have frequently occurred in winter, and the concerns about failure in power supply are soaring. One of reasons is due to the increase in industrial demand with economic recovery, and the increases in household and commercial demand with unusual cold waves are spotted as a primary cause. Especially, the diffusion of electricity heat pumps (EHP) has led to the rapid increase in commercial electricity demand. The EHP diffusion is mainly associated with low electricity tariff and cheaper heating and cooling costs compared to those of gas-engine heat pumps (GHP). The problem is that distorted electricity tariff and herd behaviour toward heating and cooling devices could bring about nation-wide inefficiencies in resource allocation. The key countermeasures are as follows. The electricity tariff should be readjusted to a realistic level. The tariff scheme should be so modified that consumers rationally respond to the tariff. In addition, one should find ways to effectively manage electricity demand.

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A Study on the Energy Consumption of Elementary Schools in Daejeon Metropolitan City (대전광역시 초등학교의 에너지 사용에 관한 조사연구)

  • Lee, Sang Hyeok;Park, Seung Ik
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.14 no.1
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    • pp.8-15
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    • 2018
  • The purpose of this study was to analyze the energy consumption according to the HVAC systems in 122 elementary schools. To do this, we classified schools according to the HVAC systems. Selected schools were classified to the following groups by the HVAC equipments: EHP, EHP and GHP together and GHP. In addition we divided schools by the number of classes. The main results are as follow: 1) Annual average energy consumption at schools was about 300~900(kWh/students), $30{\sim}50(kWh/m^2)$, 9,000~29,000((kWh/class) 2) The smaller schools, the higher the energy consumption per class; energy usage of 10~19 classes's schools were approximately 3 times higher than 40 classes's schools. 3) Schools where the EHP was installed had the lowest energy costs and energy usage. The difference in energy costs was lower than the difference in energy usage because of the fuel price and the ratio of energy sources.