• 월간 기계설비
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• s.67
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• pp.76-95
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• 1996

• 보일러설비
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• s.83
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• pp.89-95
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• 2000

• 보일러설비
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• s.72
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• pp.109-117
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• 2000

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.43 no.10
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• pp.44-51
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• 2014

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.99-104
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• 2017

This study evaluated the heating performance of a hybrid heat pump system. The system was installed in a $100-m^2$ greenhouse to utilize surplus solar energy. A hybrid heat pump system was installed at Jocheon-ri, Jeju Island, for an empirical evaluation of the performance. The system consists of a heat storage tank and plate heat exchangers for several heat exchanges between the greenhouse and heat pump or storage tank. The system uses R410a as the working fluid and is controlled automatically by a defined set temperature of the greenhouse. This system incorporates two kinds of heat sources: outdoor air and a storage tank that collects heat from the topside of the greenhouse. The results showed that the heating capacity was 19.9 kW in the outdoor air source mode and 21.4 kW with direct heating from hot water in the thermal storage tank. These results are very similar to those of a previous study.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.24 no.4
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• pp.437-449
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• 1995

• Korea Journal of Geothermal Energy
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• v.2 no.2
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• pp.5-13
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• 2006

• Korea Journal of Geothermal Energy
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• v.2 no.2
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• pp.14-22
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• 2006

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.3
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• pp.130-142
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• 2018

We use heat pumps with thermal storage system to reduce peak usage of electric power during winters and summers. A heat pump stores thermal energy in a thermal storage tank during the night, to meet load requirements during the day. This system stabilizes the supply and demand of electric power; moreover by utilizing the inexpensive midnight electric power, thus making it cost effective. In this study, we propose a system wherein the thermal storage tank and heat pump are modeled using the TRNSYS, whereas the control simulations are performed by (i) conventional control methods (i.e., thermal storage priority method and heat pump priority method); (ii) region control method, which operates at the optimal part load ratio of the heat pump; (iii) load response control method, which minimizes operating cost responding to load; and (iv) dynamic programming method, which runs the system by following the minimum cost path. We observed that the electricity cost using the region control method, load response control approach, and dynamic programing method was lower compared to using conventional control techniques. According to the annual simulation results, the electricity cost utilizing the load response control method is 43% and 4.4% lower than those obtained by the conventional techniques. We can note that the result related to the power cost was similar to that obtained by the dynamic programming method based on the load prediction. We can, therefore, conclude that the load response control method turned out to be more advantageous when compared to the conventional techniques regarding power consumption and electricity costs.

• The Magazine for Energy Service Companies
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• s.53
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• pp.62-69
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• 2008