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        검색결과 4

        1.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hydrogen has the very high heating value by comparing with other fuels and its combustion exhausts no carbon. But hydrogen causes the very high adiabatic flame temperature which generates thermal NOx. In this study, two cases of experiments were performed to compare engine characteristics. First and second cases are for only diesel combustion engine and mixed hydrogen diesel engine respectively. To verify the effect of mixed hydrogen-diesel combustion engine, the exhausted gas from modified dual fuel diesel engine was analyzed. In addition, diesel consumption per kWh for each case was estimated to validate its economic feasibility. By mixing hydrogen with 5kW brown(hydrogen-oxygen mixture) gas generator, the amount of CO(carbon mono-oxide) decreased from 330ppm to 210ppm by improving combustion and the amount of NOx increased from 390ppm to 520ppm by higher temperature of combustion chamber. Diesel consumption per kWh decreased from 450cc to 410cc but actually increased until 480cc because of the power of brown gas generator
        4,000원
        2.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        OTEC(Ocean Thermal Energy Conversion) system using the temperature difference between cooler deep and surface ocean waters is one of the renewable energy. But in Korea, OTEC system can not apply except in winter because surface sea water temperature is not enough. C-OTEC(Combined OTEC) system is that utilizes temperature difference between sea water and the condenser of power plants via working fluid. It can be a good alternative in the warm surface sea water for Mid-latitudes region like Korea. In this study, a marine survey using multi-beam echo sounder, single-beam echo sounder and sparker seismic wave is performed and sea water intake pipe line is proposed for the 10kW C-OTEC Pilot Plant.
        4,000원
        3.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Electric night storage heater was introduced and disseminated for power grid balancing and efficient management of power generation facility. But fuel cost for heating has been increased rapidly while the cost of electricity increased slightly. This abnormal rate system caused peak load in winter at last. To solve this problem, application of an air source heat pump was suggested. In the study, the effect of replacing night heater by heat pump and the economics were analysed. In addition the expectation of prospect of heat pump penetration was simulated based on surveyed and investigated data. As a result, fund supporting as well as institutional backing was needed for effective propagation and return of investment.
        4,000원
        4.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The night time electric cost is cheaper due to electric supply and demand policy in Korea from 1985. Currently about 900,000 customers are using night time electric heating boilers and this causes shift of peak demand time to night in winter and increase of deficit spending. To solve this problem, replacing night time electric heating boiler by air-source heat pump using night time electricity has been proposed. An air-source heat pump can provide efficient heating equipment especially in a warm climate. For estimating the night time electric heat pump COP(Coefficient of Performance), Korean Standard KS C 9306:2010 and European Standard EN-14511:2004 is available. SCOP(Seasonal COP) using European weather bin data is also calculated. SCOP is not available yet but European Committee for Standardization will establish a standard in the near future. The evaluation result show that the replacing night time electric heating boiler by heat pump can be possible.
        4,000원