• 제목/요약/키워드: Heating cost

검색결과 581건 처리시간 0.049초

복수정을 이용한 개방형 지열 시스템의 초기투자비 회수기간 분석 (Analysis of the Initial Cost Payback Period on the Open-loop Geothermal System Using Two Wells)

  • 조정흠;남유진
    • 설비공학논문집
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    • 제29권3호
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    • pp.119-126
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    • 2017
  • Recently, ground source heat pump systems are being used in buildings for cooling and heating to reduce greenhouse gas and save energy. However, ground source heat pump systems mainly use the vertical closed-loop geothermal system design rather than the open-loop geothermal system design. This is due to a lack of knowledge and few research feasibility studies. In this research, a dynamic thermal analysis numerical simulation based on a standard house model was conducted for an open-loop geothermal system. Based on heating load analysis results, the life cycle costs of a standard house using an open two-well geothermal system were analyzed and compared with a vertical closed-loop geothermal system, and a diesel boiler. As a result, it was found that using an open two-well geothermal system shows economic return on investment after three years.

최근 3년간 수입 유연탄 분석 및 연소열성능 해석을 활용한 석탄화력 발전소 탄종 경제성 평가 연구 (Economic Evaluation of Coals Imported in Last 3 Years for Power Plant Based on Thermal Performance Analysis)

  • 백세현;박호영;고성호
    • 한국연소학회지
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    • 제18권3호
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    • pp.44-53
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    • 2013
  • In this study, the economic evaluation for imported coals was conducted for power plant based on thermo-dynamical performance analysis. The number of coal types considered was 1,755 imported by five power generation companies in Korea during the 2010-2012. The higher heating value (HHV) of the coals ranged 4,000-6,500 kcal/kg, mostly sub-bituminous. The 1D thermo-dynamical performance modeling was performed for a 500 MWe standard power plant using PROATES code. It was founded that the low rank coals had negative effects on the plant efficiency mainly due to the increased heat loss by moisture, hydrogen and flue gas. Based on the performance analysis, the economic performance of the coals was evaluated. The apparent price of low-rank coals tended to be significantly lower than design coal; for example, the unit price of coal with a HHV of 4,000 kcal/kg was 57% of the reference coal having 6,080 kcal/kg. Considering the negative effects leading to a decrease in the thermal performance, heating value compensation, and increased parasite load, the corrected unit cost for the coal with 4,000 kcal/kg was 90.7% of the reference coal. Overall, the cost saving by imported coals was not high as expected.

수평형 지중열교환기를 이용한 건물일체형 지열시스템의 도입타당성 분석 (The feasibility study for the building integrated geothermal system using the horizontal heat exchanger)

  • 채호병;남유진;윤성훈
    • 한국태양에너지학회 논문집
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    • 제35권1호
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    • pp.81-87
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    • 2015
  • Recently, in order to prevent increasing energy usages in the international community, many countries have attempted to develop the innovative renewable energy systems. Among the renewable energy systems, Ground source heat pump(GSHP) system which supply the heating, cooling and hot water in the building has been attracted by its stability of heat production and high efficiency. However, the initial drilling costs become very expensive and the construction period takes longer the other systems, because GSHP system needs more than 100 m depth drilling. In this study, in order to reduce initial costs of the GSHP, the building integrated geothermal system using the horizontal heat exchanger was developed. The heating and cooling load in the standard housing model was calculated by a simulation and the system design capacity in the high-rise apartment was decided by the total load. Based on the system design capacity, the high-rise apartments were applied to a BIGS and vertical GSHP system and there are analyzed about initial costs. In the result, the initial cost of BIGS could reduce 24% of the initial cost of the vertical GSHP system.

한국에 있어서의 히이트 펌프계의 최적 설계 조건에 관한 연구 (A Study on Optimum Design Condition for 'HEAT PUMP' System in Korea)

  • 최영배
    • 대한설비공학회지:설비저널
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    • 제10권4호
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    • pp.304-315
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    • 1981
  • This paper presents, the result of the study for the fluctuant temperature of the out-side air adopting the heat pump system in seoul, Taejean, Taegu, Busan and Jejeu among principle cities in korea for the purpose of checking the heating capacity, Heat pump capacity (outlet capacity), Coefficient of performance and running cost in comparison with the supporting the energy for the boiler's operation. According to the supply temperature changes of the out door coil by the out side air-return air mixing ratio, the Coefficient of performance is increased from 3. 1 to 5.0. Particularly, in Taegu, it is necessary to adopt the heat pump system against the supplement heat supply on the full outside air intake in January of the heating period, and it was recognized that the running cost is cheaper than that of the Boiler use. At the same time, if it is able to get $25\%$ of return air of the inside in the Seoul, it could be saved its costs when we use the supplementary boiler. And I think it is necessary to the development.

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6kW급 태양열 온수급탕 시스템의 실증실험 및 분석 (제4보 경제성비교 및 경쟁력강화) (Verification Experiment and Analysis for 6kW Solar Water Heating System (Part 4 : Comparing Economics and Raising Competitiveness))

  • 이봉진;강채동;이상렬;홍희기
    • 설비공학논문집
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    • 제17권3호
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    • pp.232-242
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    • 2005
  • It has been recognized that solar water heating systems are economically inferior to conventional gas water-heaters and boilers using light oil as fuel in spite of having practical possibilities among other alternative energy facilities in Korea. The solar system, however, should be revaluated due to the sharp rise of oil prices recently. We have calculated the energy amount and cost through a series of research projects for the system by experiment and simulation, which lead to analyzing reliable life cycle costs. For the economic analysis, the gas water-heater and light oil boiler were taken as base cases while the solar systems implemented with these facilities were compared as alternatives. As a result, the solar system using the light oil as an auxiliary fuel surpassed the light oil boiler in economics. And a $50\%$ government subsidy for the initial cost is needed to maintain competitiveness with the gas hot-water heater. With this support, the simple payback period of the system can approach 12.8 years under $20\%$ additional curtailment of expenditure.

전동차 출입문에 에어커튼 설치시 객실 온도 변화 연구 (The Study on the Effect of Passenger Coach temperature When Aircurtains Installed At Electrical Rolling Stock At Entrance Door)

  • 안종곤;김철호;박덕신
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.489-496
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    • 2004
  • 전동차 출입문에 에어 커튼을 설치시 객실의 냉난방 효과에는 외부의 찬공기나 더운 공기를 차단하고 외부로부터의 먼지, 배기가스, 냄새, 연기 등의 침입을 방지함으로 위생에 좋으며 항상 쾌적하고 깨끗한 실내를 유지하며, 객실내의 온도 분포가 균일함으로써 건강에도 도움이 된다 냉방시의 냉기 난방시의 온기, 손실을 줄여 냉. 난방 유지비를 대폭 절감 할 수 있으며, (약 86$\%$) 설치 전보다 승객의 출입에 쾌적함을 주며 경영주에게는 경비 절감을 위한 필수품이 되며 예산 절감에 효과가 있다. 출입문 부근의 승객에게도 출입문의 개폐시 냉온의 온도 변동이 없어 승객에게 쾌적감을 느끼게 하며, 객실 온도는 출입문을 열거나 닫을 때 온도 차이가 있다. 연구의 주목적은 외풍 문제에 관계없는 만족스러운 열환경 상태를 유지하는데 있으며 전동차 출입문에 에어 커튼을 설치했을 때 온도의 변화 도를 연구하였다. 그리고 온도는 객실 바닥에서 0.1 0.5 1.3 1.7m 높이에서 측정하였으며 온도 병화의 원인은 외풍에 더 많은 영향을 받는다는 것을 발견하였다.

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사무소 건물 태양열급탕시스템의 LCC 최적화에 따른 에너지성능 변화 분석 (Energy Performance Variation of Solar Water Heating System by LCC Optimization in an Office Building)

  • 고명진;최두성;장재동;김용식
    • 한국태양에너지학회 논문집
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    • 제31권2호
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    • pp.89-98
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    • 2011
  • This study examined the energy performance according to the main design parameters of a solar water heating system for an office building using the life cycle cost (LCC) optimization simulations. The LCC optimization simulations of the system were conducted with TRNSYS and GenOpt employing the Hooke-Jeeves algorithm for cases where water temperature was $60^{\circ}C$ and $50^{\circ}C$. The results showed that for water temperature at $60^{\circ}C$ and $50^{\circ}C$ the global radiation incident on the collector could be decreased by 16.98% and 28.52%, collector useful energy gain could be decreased by 15.04% and 22.59%, energy to load from storage tank could be decreased by 10.86% and 18.06% and AH energy to load could be increased by 16.86% and 38.50% respectively compared to a non-optimized system. The annual average collection efficiency of the collector was increased by 0.88% for $60^{\circ}C$ and 2.78% for $50^{\circ}C$ because of increase of collector slope and decrease of the mass flow rate per collector area. The annual average efficiency of the system was increased by 1.74% and 3.47% compared to the basis system. However, the annual solar fraction of the system was decreased by 6.68% for $60^{\circ}C$ and 11.26% for $50^{\circ}C$ due to decrease of collector area and storage tank volume.

인공신경망 모델을 활용한 저심도 모듈러 지중열교환기의 난방성능 예측에 관한 연구 (Heating Performance Prediction of Low-depth Modular Ground Heat Exchanger based on Artificial Neural Network Model)

  • 오진환;조정흠;배상무;채호병;남유진
    • 한국지열·수열에너지학회논문집
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    • 제18권3호
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    • pp.1-6
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    • 2022
  • Ground source heat pump (GSHP) system is highly efficient and environment-friendly and supplies heating, cooling and hot water to buildings. For an optimal design of the GSHP system, the ground thermal properties should be determined to estimate the heat exchange rate between ground and borehole heat exchangers (BHE) and the system performance during long-term operating periods. However, the process increases the initial cost and construction period, which causes the system to be hindered in distribution. On the other hand, much research has been applied to the artificial neural network (ANN) to solve problems based on data efficiently and stably. This research proposes the predictive performance model utilizing ANN considering local characteristics and weather data for the predictive performance model. The ANN model predicts the entering water temperature (EWT) from the GHEs to the heat pump for the modular GHEs, which were developed to reduce the cost and spatial disadvantages of the vertical-type GHEs. As a result, the temperature error between the data and predicted results was 3.52%. The proposed approach was validated to predict the system performance and EWT of the GSHP system.

큰느타리버섯 재배사의 경제성 분석 (Economic Analysis of Pleurotus Eryngii Cultivation Facilities)

  • 서원명;윤용철
    • 한국농공학회논문집
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    • 제48권6호
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    • pp.31-41
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    • 2006
  • The analysis used in this work was cost-benefit analysis method. All future costs and returns of a given mushroom house were discounted to the time of initial investment (present) by means of 3.5% discount rate. Then the cost of ownership was compared to the return from the system. This analysis method has been developed and coded into a balance sheet for use on a EXCEL program. Using this programmed analysis,a large number of the case studies were examined using different combinations of economic conditions. These results will be very useful to individuals considering investment in a mushroom house, or any similar production system. By the way of the sensitivity analysis for each important parameter, the change of the marginal cost-benefit period could be finally determined. These parameters were typically construction cost of mushroom house, cost of cooling system, required cooling and heating energy amounts, unit price of mushroom media bottle, growing number of media bottles, production weight per unit bottle, sale price of mushroom, and annual number of growing period, etc.

청주시 저소득 가구의 가정 에너지 비용 부담 경험과 인식 (Low-income Households' Experiences and Perception of Home Energy Cost Burdens in Cheongju, South Korea)

  • 이현정
    • 한국주거학회논문집
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    • 제26권5호
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    • pp.79-87
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    • 2015
  • This study explored low-income households' experiences and perception of home energy cost burdens and determinants of the perceived home energy cost burdens. Between March and July 2014, a questionnaire survey was administered in Cheongju, South Korea. Among the 434 useable responses collected, responses from 218 households with monthly income less than 2,500,000 Korean Won (KRW) were compared with those of 216 households with higher incomes. The main findings are as follows. In the past three years, more than 10 percent of low-income households had had their electricity cut off; 5.7 percent had had their city gas cut off. To pay for their home energy expenses, nearly 70 percent of the low-income households had had to limit their heating, cooling or spending for other necessities; 38.3 percent had to borrow money. Low-income households reported more problems paying for home energy than higher-income households did. Households with more negative evaluation of rainwater leak, no one staying at home all day, monthly income less than 1,500,000 KRW and householders in their 40s and 50s tended to perceive a heavier home energy cost burden. Finally, the most popular support programs were fuel assistance and discounts on energy bills.