• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1043-1048
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• 2009

This paper proposes the new operation control method that let heat source system stop and circulate only hot water at low load, and verified the introduction effect. At first, we constructed simulation model of heat source system and examined the proposing method by using simulation model. At last, we examined the introduction effect of proposing method with actual building. As a result, the primary energy consumption of heat source system was reduced by about 13%.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.82-87
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• 2007

In the present study, the simulation on the annual performance evaluation of a renewable energy systems with fuel cell driven compound source hybrid heat pump systems is applied to the heating and cooling of large community building. The large community building has the economical advantage to apply heat pump cooling and heating systems the long period operation. If air and ground source hybrid heat pump systems are combined, COP of the system can be increased largely. Fuel cell driven compound source hybrid heat pump system can reduced the fuel cost as well as thermal storage tank sharply.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 하계학술발표대회
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• pp.67-67
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• 2005

• 대한설비공학회지:설비저널
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• 제26권3호
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• pp.151-161
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• 1997

• Journal of the Korean Wood Science and Technology
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• 제39권6호
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• pp.512-520
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• 2011

본 연구에서는 탄화과정 중에 탄화로에서 발생되는 폐열을 활용하기 위해서 친환경건조시스템을 개발하여 그 특성을 검토하였다. 친환경건조시스템은 화석연료를 전혀 이용하고 있지 않고, 버려지는 폐열을 이용하기 때문에 환경친화적이다. 친환경건조시스템의 열원으로 이용되는 열수는 3개의 탄화로에 서로 연결되어 폐열을 회수하고 있고, 지속적인 열원의 공급으로 건조기내의 온도와 습도변화는 크지 않았다. 친환경건조시스템 설치가 목탄의 특성에 미치는 영향을 조사하기 위하여 고정탄소, 정련도, 경도, 발열량, pH, 단위중량당 발열량, 수탄율을 분석하였다. 그 결과로부터 친환경건조시스템 설치가 목탄의 특성에 크게 영향을 주지 않는 것으로 나타났다. 따라서 버려지는 폐열을 회수하여 에너지로 이용하는 친환경건조시스템은 에너지절감과 농산물의 건조품질을 향상시켜 농가의 수익을 극대화할 수 있는 효과가 있을 것으로 생각된다.

• 설비공학논문집
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• 제28권5호
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• pp.178-185
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• 2016

This study describes the analysis of a 20 MW chilled water plant used for the IT cooling of a recently constructed data center in Korea. The CFD model was developed with the aim of evaluating the impact of problems such as chiller failure on the water and air temperatures in the cooling system. The numerical model includes the chilled water hydraulic network and individual water-to-air CRAC units. The coupling between the IT server room air temperature levels and the cooling plant has enabled a full assessment of the cooling system design in response to system fault conditions to be performed. The paper examines an emergency situation involving the failure of the cooling plant, and shows how the inherent thermal inertia of the system along with additional inertia achieved through buffer systems allowed a suitable design to be achieved.

• 한국지열·수열에너지학회논문집
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• 제9권1호
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• pp.8-14
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• 2013

HVAC&R systems are the most energy consuming building services representing approximately half of the final energy use in the building sector. Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research, mainly due to the complexity and variety of HVAC&R systems but also to insufficient rigour in their energy analysis. This research reviews energy consumption of HVAC&R systems with the aim of establishing a common idea for the analysis of energy efficiency. The paper focuses on energy flow of the HVAC&R which include air-conditioning, transport and heat generation system for low-energy buildings.

• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.26-31
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• 2013

Use of heat from seawater could be different from the weather conditions of a coastal city and seawater temperatures near the city. It will be a good option to use surface layer water with Heat Pump system for using seawater cooling/heating in Jeju. The study investigates the proper depth for seawater heat gain of Jeju area in Korea. Sampling points are 0, 10, 20, 30m from the surface of the Sea. Seawater temperature does not change significantly according to the depth in winter, while the temperature is quite different according to the depth in summer. In this study, it is analyzed to compare existing system and seawater heat source system for target buildings on Jeju. And this systems are calculated a initial cost.

• 설비공학논문집
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• 제16권12호
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• pp.1175-1182
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• 2004

Installations of vertical boreholes for the ground source heat pump system are expensive to install. One way to reduce the initial cost is to increase the specific heat extraction rate of borehole system. However, as the specific heat extraction rate increases the temperature of borehole fluid decreases with the resultant lower Coefficient Of Performance in Heating(COPH) of heat pump system. The purpose of this study is to provide the basic informations about the performance of heat pump system with the specific heat extraction rate and soil thermal properties such as thermal conductivity and temperature. It is shown that the specific heat extraction rate is the most important parameter for the ground source heat pump system. To obtain the reasonable COPH value (COPH > 3) the heat extraction rate should be about 25 W/m or less. Accurate measurements of soil thermal properties are also very important to design the system properly. The effects of borehole thermal resistances are also examined in this study.

• 한국수소및신에너지학회논문집
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• 제32권1호
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• pp.77-85
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• 2021

In this paper, entransy analysis is carried out for combined heat and power (CHP) generation system driven by low-grade heat source compared with energy and exergy analyses. The system consists of an organic Rankine cycle (ORC) and an additional process heater in a parallel circuit. Special attention is paid to the effects of the source temperature, turbine inlet pressure, and the working fluid on the thermodynamic performance of the system. Results showed that the work efficiency of entransy is higher than that of energy but lower than that of exergy, wheress the process heat efficiency of entransy is lower than that of energy but higher than that of exergy. Entrancy analysis showed the potential to complement the exergy analysis in the optimal design of the energy system.