• 제목/요약/키워드: R-245fa

검색결과 47건 처리시간 0.024초

20kW급 폐열회수 시스템 공정 설계에 관한 연구 (A Study on the Engineering Design for 20kW-Grade Waste Gas Heat Recovery)

  • 김경수;방세경;정은익;이중섭
    • 한국기계가공학회지
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    • 제17권4호
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    • pp.91-96
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    • 2018
  • This study is collects design data through the process design of the organic Rankine cycle, which can produce 20kW of electric power through the recovery of waste heat. In this study, the simulation was conducted by using APSEN HYSYS in order to make the model for the process design of the 20kW class waste heat recovery system. For the thermodynamic model, the test was conducted with hot water as the heat source, with the water steam used as the cooling water for the cooler and the refrigerant R245fa in the cycle. In Case 1 and Case 2, it was expected and found that the cycle efficiency was 10.6% and that 36.86kw was produced, considering the margin of 84% of 20kW. In Case 3 and Case 4, it was expected and found from the simulation that the cycle efficiency was 12% and that 30.0kw was produced, considering the margin of 84% of 20kW.

신재생에너지 가변열원의 효율적 이용을 위한 유기랭킨 사이클 최적작동점에 관한 연구 (Optimal Operating Points on the Organic Rankine Cycle to Efficiently Regenerate Renewable Fluctuating Heat Sources)

  • 조수용;조종현
    • 신재생에너지
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    • 제10권1호
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    • pp.6-19
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    • 2014
  • Organic Rankine cycle (ORC) has been widely used to convert renewable energy such as solar energy, geothermal energy, or waste energy etc., to electric power. For a small scale output power less than 10 kW, turbo-expander is not widely used than positive displacement expander. However, the turbo-expander has merits that it can operate well at off-design points. Usually, the available thermal energy for a small scale ORC is not supplied continuously. So, the mass flowrate should be adjusted in the expander to maintain the cycle. In this study, nozzles was adopted as stator to control the mass flowrate, and radial-type turbine was used as expander. The turbine operated at partial admission. R245fa was adopted as working fluid, and supersonic nozzle was designed to get the supersonic flow at the nozzle exit. When the inlet operating condition of the working fluid was varied corresponding to the fluctuation of the available thermal energy, optimal operating condition was investigated at off-design due to the variation of mass flowrate.

엔진 배기열 회수 증발기 설계를 위한 유기랭킨사이클 분석 (Analysis of organic rankine cycle for designing evaporator of engine exhaust heat recovery system)

  • 고제현;최병철;박권하
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권5호
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    • pp.446-452
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    • 2013
  • 탄소저감 기술과 함께 에너지 효율 향상에 대한 관심이 증가하고 있다. 엔진에서 대기로 방출되는 배기에너지는 전체에너지의 30%가 넘는 많은 양이며 배기열을 회수하기 위한 많은 연구가 진행되고 있다. 본 연구에서는 선행연구를 통하여 제시한 디젤엔진에서의 최적 열 회수 조건에 대한 랭킨사이클을 분석하였다. 그 결과 질량유량비와 압력비가 각각 0.6, 0.7 일 때 엑서지 효율과 출력은 0.53, 1.43 kW을 나타내었다.

250kW급 폐열회수 시스템 공정설계에 관한 연구 (A Study on the Engineering Design for 250kW-Grade Waste Gas Heat Recovery)

  • 김경수;방세경;서인호;이상윤;정은익;이중섭
    • 한국기계가공학회지
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    • 제18권5호
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    • pp.90-95
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    • 2019
  • This study aims to gain the design data through the process design of the organic Rankine cycle, which can produce 250kW of electric power through waste heat recovery. In this study, a simulation was conducted using APSEN HYSYS to make the model for the process design of the 250kW-class waste heat recovery system. For the thermodynamic model, the test was conducted with hot water as the heat source, the water steam as the cooling water for the cooler, and the refrigerant R245FA in the cycle. In the final design, it was expected and found from the simulation that the cycle efficiency was 12.62% and that 250kW of power was produced considering the margin of 80%.

120℃ 스팀 생성을 위한 100 kW급 히트펌프의 실험적 연구 (Experimental Study on Heating Performance Characteristic of 100 kW Heat Pump to Generate ℃ Steam)

  • 왕은석;나선익;이길봉;백영진;이영수;이범준
    • 설비공학논문집
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    • 제30권2호
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    • pp.100-106
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    • 2018
  • Recently, the development of a heat pump technology to recover process waste heat and to generate steam of $120^{\circ}C$ or higher required for industrial processes, has attracted attention. The research of conventional heat pump utilizing the available energy is used primarily for air conditioning, and the production temperature is about $60^{\circ}C$, so it is difficult to utilize it for industrial use. Therefore, in this study, we developed a steam heat pump (SGHP) which recovers the waste heat of process and generates steam at $120^{\circ}C$. The low-pressure refrigerant R245fa, considered to be an eco-friendly refrigerant, has been selected as the refrigerant for SGHP in this study since its Ozone Depletion Potential (ODP) is zero and the Global Warming Potential (GWP) is relatively low. A flash tank functioning as a phase separator was installed in the rear stage of the condenser, and the saturated water of high temperature was decompressed to generate steam. It was started at the initial temperature of $70^{\circ}C$, and it was confirmed that $120^{\circ}C$ steam was produced after the system stabilized. We have conducted experiments by modifying the system, and ultimately achieved a heating capacity of 101.4 kW and a COP of 3.05.

중온 배기열을 이용한 유기랭킨사이클 작동유체별 성능특성 (Performance Characteristics of Organic Rankine Cycle Using Medium Temperature Waste Heat with Different Working Fluids)

  • 권동욱;허기무;윤성훈;문윤재;유호선;이재헌
    • 플랜트 저널
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    • 제10권2호
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    • pp.38-47
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    • 2014
  • 2012년부터 신재생에너지 의무공급제도가 국내에 도입되고, 전 세계적인 에너지 절약과 환경보존 측면에서 미활용 및 신재생에너지원에 대한 관심이 날로 증가하고 있다. 특히, 중저온 열원의 활용방안에 대하여 많은 관심과 연구가 활발하게 진행되면서 고부가가치의 전력생산이 가능한 유기랭킨사이클이 그 대안으로 떠오르고 있다. 따라서 본 연구에서는 유기랭킨사이클 발전시스템을 하수 처리장 1,500 kW 바이오가스엔진 배기열을 열원으로 하부 사이클을 구성하여 성능해석 상용 프로그램으로 성능특성을 예측하였다. 바이오가스엔진 배열의 실제 운전조건은 $460^{\circ}C$의 온도와 매 초당 2.7 kg의 유량으로 운전되고 있었다. 이러한 열원 온도에 적합한 작동유체를 다수 선정하여 작동유체 종류별 성능해석을 수행하였으며, 최고의 성능이 나타나는 이소펜탄의 경우 163.1 kW의 발전출력과 13.66%의 효율을 얻을 수 있었다.

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설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제29권6호
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    • pp.327-340
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    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.