• 한국식품저장유통학회지
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• 제14권5호
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• pp.487-491
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• 2007

새싹 채소 중 무순의 위생적인 재배 조건을 위한 종자에 대한 이산화염소수와 열수처리 효과를 조사하였다. 이산화염소수와 열처리를 단독처리 또는 복합처리를 통하여 무종자의 발아율과 미생물의 감소를 조사한 결과, 단독처리시 100 ppm 농도 이상의 이산화염소수로 10분 이상 처리시 대조구와 비교하여 1 log cycle이상 감소하였으나, 열수처리 온도 $45^{\circ}C{\sim}55^{\circ}C$에서는 미생물의 감소가 1 log cycle 이하의 미미한 감소효과를 나타내었다. 발아율은 이산화염소수의 처리에 의한 영향은 없었으며 열처리 온도 $45^{\circ}C{\sim}50^{\circ}C$에서는 열처리에 의한 발아율이 증가한 반면, $55^{\circ}C$/10분 이상 처리구에서 발아율이 감소하여 $55^{\circ}C$/20분 처리 시 대조구에 비하여 발아율 약 10% 이상 감소하였다. 이산화염소수 50 ppm, 100 ppm과 열수 온도 $45^{\circ}C,\;50^{\circ}C$간의 복합처리는 발아율의 증가와 미생물의 감소효과를 나타내었으며, 특히, 100 ppm의 농도에서 병행 처리 시 약 2 log cycle의 미생물 감소효과와 발아율이 $97.0{\sim}97.7%$로 증가하는 경향을 나타내었다. 결론적으로, 이산화염소수와 열수의 복합처리는 무 새싹채소의 종자에 미생물적 안전성을 증가 시킴과 동시에 발아율을 증가시키는 것으로 판단된다.

• 설비공학논문집
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• 제22권5호
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• pp.296-303
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• 2010

An experimental study was carried out to investigate performance characteristics of the hybrid solar system during spring season. The system operating condition, each load, and heat pump performance were analyzed with the cloud cover. As a results, the collector heat, solar fraction, and hot water load were decreased with a rise of the cloud. The heating load was considerably effected by the ambient temperature regardless of the cloud cover. Besides, the temperature of hot water increased with the solar radiation. The COP of the heat pump was significantly influenced by the ambient temperature, that was 2.09~2.46 for gray day and 1.94~2.71 for fair day, respectively.

• 설비공학논문집
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• 제21권12호
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• pp.695-702
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• 2009

Dynamic behavior of Libr-water absorption system using low-temperature hot water was investigated numerically. Thermal-hydraulic model of single-effect/double-lift 100 RT chiller was developed by applying transient conservation equations of total mass, Libr mass, energy and momentum to each component. Transient variations of system properties and transport variables were analysed during start-up operation. Numerical analysis were performed to quantify the effects of bulk concentration and part-load operation on the system performance in terms of cooling capacity, coefficient of performance, and time constant of system. For an absorption chiller considered in the present study, optimum bulk concentration was found to exist, which resulted in the minimum time constant with stable cooling capacity. COP and time constant increased as the load decreased down to 40%, below which the time constant increased abruptly and COP decreased as the load decreased further.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1037-1042
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• 2009

In connection with a recent research project dealing with heating system in apartment buildings by district heating, it was realised that in general very little information on the actual performance of heating and hot water systems in apartment buildings has been documented. In order to improve of district heating systems, a prediction of the heat demand first needs to be determined before a production plan. this is hot water heat system developed in this paper. this is also analyzed relation heat load with preheat load in hot water heating exchanger system.

• 한국태양에너지학회 논문집
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• 제32권6호
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• pp.53-59
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• 2012

This study was carried out to evaluate thermal performance of the renewable hybrid heat supply system with solar thermal system and wood pellet boiler for Zero Carbon Green home of apartment houses. The hybrid heat supply system was set up at Korea Institute Energy Research in 2011. The system was comprised of the wood pellet boiler unit with heat capacity designed as 20,000kcal/hr, a $0.15m^3$ hot water storage tank for space heating, a evacuated tubular solar collector $3.74m^2$ of aperture area at the $20^{\circ}$ install angle, a $0.3m^3$ hot water storage tank. Thermal performance tests for one-house of apartment house were carried out by hot water load and heating load in winter season through the hybrid heat supply system. As a result, hot water energy supplied by the hybrid heat supply system was 11kWh in a day. Solar thermal energy portion was 2.99kWh which is 27% of the total hot water energy supply. wood pellet boiler supply portion was 8.017kWh which is 73% of the total hot water energy supply.

• 대한건축학회논문집:구조계
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• 제34권11호
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• pp.55-62
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• 2018

To receive financial support for the Green Remodeling, applicants must submit an energy simulation report. However, many of the applicants are not green remodeling specialist and energy simulation services are too expensive for them. For this reason, this study was to develop an energy simulation program to enhance green remodeling for the non-specialist such as housewives. Firstly, to enhance understanding and accessibility improvement energy simulation, simulation process was designed four steps and reducing input data. Specifically, input data was reduced by categorizing the following for the area, plan type, hot water load, electricity load, statistical inference. And then, to accurately verify the calculation result, the heat and hot water demand were derived and compared with ECO2 and Energy # program. Lastly, the calculation shows that there is a difference of 4% for the heat load and 15% to 33% for the hot water load respectively.

• 한국태양에너지학회 논문집
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• 제29권5호
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• pp.1-7
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• 2009

Energy demands for offices in Korea are surveyed and analyzed to generate communicational models for simulations. Daily energy loads of 13 office buildings scattered in the 6 largest cities in the country are surveyed and analyzed based on energy consumption log sheets. Detailed hourly loads that are frequently required when a detailed operation simulation is performed are measured using remote data acquisition processes for 3 offices. The complete load demand models of electricity, cooling, heating and hot water are established by combining the daily and hourly patterns based on the statistical behavior of the hourly patterns.

• 한국유체기계학회 논문집
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• 제18권1호
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• pp.29-36
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• 2015

Recently, Stirling engines are emerging as a key device for power conversion of renewable energy or waste energy. This study develops a LTDSE(Low Temperature Differential Stirling Engine) using a water spray for higher heat transfer and performs load performance tests for various flow rates and temperatures of hot water spray for variable engine loads emulated by a mechanical friction device. Internal temperature and pressure, working frequency and inlet and outlet temperature of the supply water are measured. As a result, the increases in flow rate and temperature of hot water respectively enhance the power output, efficiency and the working frequency, while the increasing engine load leads to decreases in working frequency but increases in the pressure amplitude. Eventually, it is revealed there exists a maximum shaft power of the test engine.

• 에너지공학
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• 제21권4호
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• pp.435-443
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• 2012

세계는 원유재고 감소와 국제 정세의 불안정으로 인해 지속적으로 상승하고 있는 유가와 화석연료 사용으로 인한 환경오염에 관심이 고조되고 있다. 국내의 경우 원유를 100% 수입하고 있으며, 사용되고 있는 에너지의 에너지원 중 97%를 수입에 의존하고 있기 때문에 유가 상승에 따른 영향은 더욱 민감하게 나타난다. 국내에 수입되고 유통되는 에너지의 97% 중 1/3 이상이 사무소나 주거용 난방, 급탕 및 취사용으로 사용되고 있다. 이에 따라 정부는 물론 산업체, 연구소 등에서 사무소 및 주거용 에너지 소비패턴으로 인한 경제적인 부담을 줄이고, 고효율 저에너지 기술개발을 통해 소비에너지를 절약함과 동시에 탄소배출을 억제하는 신기술에 대한 연구가 활발하게 이루어지고 있다. 우리나라는 국토가 좁은 반면 인구밀도가 높고, 인구의 도시집중화로 공동주택의 주거비율이 높은 추세이기 때문에 최근 공동주택단지는 초고층화, 대형화가 되고 있으며, 이로 인해 급수 급탕에 대한 사용패턴도 변화하고 있다. 하지만 현재 급수 급탕에 대한 설계 자료는 대부분 외국의 설계 기준과 현장 경험치에 의해 산출된 데이터에 의존하고 있으며, 사용실태에 대한 기초자료가 부족한 실정이며, 이로 인해 급수 급탕 설비 설계 시 과대 또는 과소 설계가 되는 문제가 발생하고 있다. 본 연구에서는 공동주택의 공급자 측 급탕 열 공급환경과 사용자측 열사용량을 측정하여, 급탕부하가 발생하는 시간과 사용 실태 및 패턴을 파악함으로써, 효율적인 공급자 측 급탕설비 설계와 관리를 위한 기초자료를 제시하고자 한다.

• 한국태양에너지학회 논문집
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• 제26권2호
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• pp.103-109
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• 2006

The Purpose of this work is to investigate a long-term thermal performance of active solar hot water heating system for the dormitory of university. For this, monitering system including temperature sensors, flow-meters was installed in this system. Measurement was continued for 13 months between April 1st 2004 and May 31th 2005. As results, hot water demand, daily and monthly hot water load distribution which are necessary for the solar system design were suggested. Also thermal stratification in solar buffer tank was observed in the point of increasement of system efficiency. The yearly solar fraction and system efficiency of this system are about 29.5% and 44.9% respectively.