• 제목/요약/키워드: Heating cost

검색결과 576건 처리시간 0.031초

고온가공기법을 이용한 초경소재 가공기술에 관한 연구 (A Study on Cutting Method of Tungsten Carbide Material Using Hot Machining)

  • 정연행;조영갑
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 추계학술대회논문집
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    • pp.315-318
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    • 2004
  • The Advantages of hot machining are the reduction of cutting forces, tool wear, and the increase of material removal rates. In this study, a hot-machining characteristics of milling by CBN tip was exprimentely analyzed, and the influence of the surface temperature and the depth of cut on the tool life were investigated. The selection of a heating method for obtaining ideal temperature of metals in machining is important. Faulty heating methods could induce unwanted structural changes in the workpiece and increase the cost. This study uses gas flame heating. It is obtained that tungsten carbide-alloyed has a recrystallisation temperature range of $800-1000^{\circ}C$ which is the high heating temperature that might induce unwanted structural changes. If it is performed at temperatures higher than $800^{\circ}C$ in machining, the possibility of unwanted structural changes and the increased wear of tool can be shown. Consequently, in hot machining of tungsten carbide-alloy, this study has chosen $400^{\circ}C-600^{\circ}C$ because the heating temperature might be appropriate in view of the cost and workpiece considerations. The results of this study experimentally shows a new machining method for tungsten carbide-alloyed that decreases the wear rate of machining tools

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동적계획법을 이용한 고온수배관의 최적보온설계에 관한 연구 (A study on the optimal design for heat insulation of hot water piping systems using a dynamic programming)

  • 유희한;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • 제11권1호
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    • pp.39-52
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    • 1987
  • Recently, the design problem of heat insulation have been reappraised in the aspect of energy saving due to the rising trend of energy cost. For example, that design problem is increasingly requsted in the fields of accommodation air conditioning systems, hot water supply systems, cargo handling systems, district heating or cooling systems. The rational design of heat insulation of piping systems can not only improve the overall efficiency of energy transfer but also give energy saving. In this paper, the heat insulation problem of district heating systems is therefore modeled as the multi-stage decision processes, suitable for dynamic programming technique. And take the object function as the sum of heat insulation material cost involved construction cost and heat loss cost, and propose the design method to minimize the object function for overall piping systems by dynamic programing. Effectiveness of design method presented here is proved by a computer simulation.

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열병합시스템 경제성 평가 프로그램의 개발 및 적용에 관한 연구 (Development and Application of an Economic Assessment Program of Cogeneration Systems)

  • 박차식;김용찬
    • 대한기계학회논문집B
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    • 제22권11호
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    • pp.1547-1554
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    • 1998
  • The object of this study was to develop an economic assessment program for the optimal design of the cogeneration systems composed of combining engine, generator, waste heat recovery exchanger, absorption chiller, and boiler, etc. The energy demand categorized by electric power, heating, cooling and water supply was determined by statistical data of the existing cogeneration systems. An economic assessment was performed by comparing the total cost of cogeneration system with that of non-cogeneration system. The total cost was evaluated by adding initial investment to operational cost considering efficiency of equipment, cost of equipment, fuel and electricity. To confirm the validity of the developed program, a hotel building with an area of $127,960m^2$ was selected, and the simulated results were compared with the measured data. The difference between the simulated and the measured values for the selected hotel building was approximately 12% for annual electric consumption.

원적외선 난방시스템이 방울토마토 생육에 미치는 영향 (Growth Characteristics of Cherry Tomato in Greenhouse using Far Infrared Heating Systems)

  • 김희준;리혁;강태환;녕효봉;한충수;조성찬
    • Journal of Biosystems Engineering
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    • 제34권3호
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    • pp.161-166
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    • 2009
  • This study was conducted to investigate the growth characteristics of cherry tomatoes in greenhouse using far infrared heating system. The far infrared greenhouse heating systems were installed in two ways on the greenhouse side wall and at the greenhouse ceiling. The heating characteristics of far infrared heating system were analyzed by investigating the heating load, internal temperature, energy consumption, growth characteristics and quality evaluation. The results were compared with heated air heating system using kerosene. The results showed that tomatoes grown in the greenhouse with the far infrared heating system had relatively better plant height, leaf length, leaf width, stem diameter than ones from the greenhouse with hot air heating system and both heating methods had no significant difference on Cherry tomato sugar contents. At the same time, the far infrared heating system reduced heating cost from 34.5 to 41.4% on comparing with hot air heating system.

에너지절약설계기준의 단열 변화에 따른 공동주택 실효성 검토 - 난방 및 급탕에너지 사용금액 분석 - (Review on the Effectiveness of Apartments According to Insulation Reinforcement of Energy Saving Design Standard - Energy Cost Analysis of Space Heating and Domestic Hot Water -)

  • 김지현;임희원;이현승;신우철
    • 대한건축학회논문집:구조계
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    • 제36권1호
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    • pp.173-178
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    • 2020
  • In this study, we analyzed space heating and domestic hot water(DHW) charges from 2017 to 2018 for 151,206 households in 202 apartment complexes built from 1997 to 2016, in order to evaluate the effectiveness of Korea's insulation standards reinforcement. The applied insulation standards were revised three times(in 1987, 2001 and 2010). We used the Anderson-Darling test to review the normality of the space heating and DHW charges. As a result, each p-value was greater than 0.05 and it followed the normal distribution. The annual average space heating charges per unit area of apartments with the 1987 insulation standards were 5,237₩/㎡a in 2017 and 5,328₩/㎡a in 2018. The heating charges with the 2001 standards were 4,827₩/㎡a in 2017 and 4,817₩/㎡a in 2018. Compared to previous standards(1987 standards), heating charges decreased by 7.8% and 9.6%. Also the heating charges with the 2010 standards were 3,683₩/㎡a in 2017 and 3,734₩/㎡a in 2018. Compared to previous standards(2001 standards), heating charges decreased by 24.3% and 21.5%. On the other hand, compared to each previous standards, DHW charges were decreased by 12.2%, 13.6% or increased by 4.6%, 6.9%, which means there's no correlation between insulation standards reinforcement and DHW charges.

미세 임프린팅용 금속몰드의 급속가열을 위한 유도가열기구 개발 (Development of Induction Heating Apparatus for Rapid Heating of Metallic Mold)

  • 홍석관;이성희;허영무;강정진
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2007년도 춘계학술대회 논문집
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    • pp.199-204
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    • 2007
  • Hot embossing, one of Nanoimprint Lithography(NIL) techniques, has been getting attention as an alternative candidate of next generation patterning technologies by the advantages of simplicity and low cost compared to conventional photolithographies. A typical hot embossing usually, however, takes more than ten minutes for one cycle of the process because of a long thermal cycling. Over the last few years a number of studies have been made to reduce the cycle time for hot embossing or similar patterning processes. The target of this research is to develop an induction heating apparatus for heating a metallic micro patterning mold at very high speed with the large-area uniformity of temperature distribution. It was found that a 0.5 mm-thick nickel mold can be heated from $25^{\circ}C$ to $150^{\circ}C$ within 1.5 seconds with the temperature variation of ${\pm}5^{\circ}C$ in 4-inch diameter area, using the induction heating apparatus.

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지역난방의 환경개선효과 측정에 관한 연구 (A Study on the Enviromental Impact of District Heating System)

  • 손양훈;박주헌;조전혁
    • 자원ㆍ환경경제연구
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    • 제10권3호
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    • pp.367-386
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    • 2001
  • In this paper we analyze the environmental advantages of district heating system. We construct three econometric models to analyze the energy consumption and economic cost as well as the emission of the major pollutants like $SO_x$, $NO_x$, DUST, and $CO_2$. As the size of heating supply is larger, the district heating system is evaluated to be better than other heating systems environmentally and costly in the long run. Especially, the district heating reduces $SO_x$ emission significantly when the size of heat production is large. But the advantages of district heating system are very sensitive to the fuel mix and heat source.

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바이오매스를 이용한 농업용 난방계획의 경제성 검토 (Economic Assessment of Biomass Heating for Rural Application)

  • 홍성구
    • 한국농공학회논문집
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    • 제47권2호
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    • pp.45-52
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    • 2005
  • Biomass is one of the most competitive renewable energy resource and can be used for heating for rural applications. A economic assessment was made of biomass heating, using the tool BIOH2000 from $RETScreen^{\circledR}$ International Clean Energy Decision Support Centre. For a 260kW heating system for 50 farm houses, the assessment showed a very promising results. Internal rate of return was $19.7\%$ and year-to-positive cash flow was 5.1 years. Relative price of biomass over fossil fuel significantly affected the economic feasibility of the project. Heating demand was directly related to annual demand of biomass and economic feasibility. Relative cost of distribution pipe over the total initial costs also affected the economic feasibility of the project. The economic feasibility was expected to be improved by the probable greenhouse emission reduction credit and reduction of initial costs through utilizing existing heating system for peak or back up heating system.

선박용 프로펠러 주조시 수축결함 제어용 압탕가열장치 적용 (Application of the Riser Heating Equipment to Control Shrinkage defects for Casting of the Propeller)

  • 문현준;김정섭;박태동;이동조;윤석환
    • 한국주조공학회지
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    • 제28권2호
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    • pp.74-78
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    • 2008
  • An integrated riser heating equipment has been developed to control shrinkage defects originated from casting of a marine propeller. The integrated riser heating equipment is composed of up/down moving parts, heating power source parts and an integrated controller. Heat capacity putting into the riser was calculated quantitatively on the base of a heat transfer analysis, which consisted of the establishment of heating model and the theoretical analysis for heat transfer. The riser heating equipment was evaluated through arc heating and electro-slag heating method. With the results, the arc type heating method was selected by considering high thermal efficiency, inexpensive cost, and convenient workship. This equipment improves the quality of a propeller casting and the poor working environment.