• Title/Summary/Keyword: Heat load

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Heat Release Characteristics of Typical Live Fire Load in Large Bookstore (대형서점 적재가연물의 초기 연소발열성상)

  • Nam, Dong-Gun
    • Fire Science and Engineering
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    • v.25 no.2
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    • pp.88-94
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    • 2011
  • Heat release characteristics of live fire load are an important parameter for performance oriented fire safety design of a building. While investigations have been carried out on the fire load and its burning behavior in office, residential and commercial buildings and so on, little effort has been paid for the rational treatment of fire load in bookstore. In this report, burning behavior of typical combustible objects in bookstore are studied by measuring heat release rates of bookshelf with book. Based on the results, it has reviewed fire safety when a fire accident occurs on the large bookstore and suggested peak heat release rate per burning surface, fire growth rate, etc of the live fire load required for fire safety design in bookstore.

Thermal load analysis of tank culture system for applying seawater source heat pump (육상 수조식 양식장의 해수 열원 히트펌프 시스템 적용을 위한 열부하 분석)

  • Min-Gi YOON;Tae-Hoon KIM;Seok-Kwon JEONG
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.2
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    • pp.155-163
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    • 2023
  • This study deals with the maximum thermal load analysis and optimal capacity determination method of tank culture system for applying seawater source heat pump to save energy and realize zero energy. The location of the fish farm was divided into four sea areas, and the heat load in summer and winter was analyzed, respectively. In addition, two representative methods, the flow-through aquaculture system and the recirculation aquaculture system were reviewed as water treatment methods for fish farms. In addition, the concept of the exchange rate was introduced to obtain the maximum heat load of the fish farms. Finally, power consumption for heat pumps was analyzed in the view point of sea areas, tank capacity, and exchange rate based on the calculated maximum thermal load.

A Study on the Fire Resistance Performance of Reinforced Concrete Columns according to Axial Load Ratio (축력비 조건에 따른 철근콘크리트기둥의 내화성능에 관한 연구)

  • Hwang, Kyu-Jae;Cho, Bum-Yean;Yeo, In-Hwan
    • Fire Science and Engineering
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    • v.27 no.6
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    • pp.26-31
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    • 2013
  • This study, to evaluate the technology of the fire resistance design of Reinforced Concrete columns based on fire resistance performance design, was suppose to use as basic data for performance design through a measure of temperature and deformation using heat transfer analysis and Heat-load test of the Reinforced Concrete columns as parameter is the axial load ratio. In accordance with axial load without eccentricity, the load ratio of 0.30, 0.35, 0.40 and 0.47 were imposed on columns. As a result of this study, 0.40 or more of axial load ratio can be ensured that the fire resistance performance was considered satisfactory.

Performance Analysis of Water-to-Air Heat Pump System under Water Temperature and Load Ratio (열원 및 부하조건에 따른 물-공기 히트펌프 시스템의 성능분석)

  • Cho, Yong;Lee, Dong Keun
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.05a
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    • pp.194.2-194.2
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    • 2011
  • Heating and cooling performance has been analyzed for the water-source heat pump system using raw water from Daechung reservoir. During heating operation from March to May, water temperature is not good condition for a heat source due to the higher atmospheric temperature. Avearged heating load ratio is only 14.3%, and the averaged unit COP and system COP are estimated to be 2.46 and 2.15 respectively. The COP is affected considerably by the water temperature, and the unit COP is increased from 2.16 at $5^{\circ}C$ to 2.95 at $11^{\circ}C$. Cooling performance is analyzed with the measured data from June to August. During cooling operation, raw water has lower temperature by 4. $5^{\circ}C{\sim}4.7^{\circ}C$ than the atmosphere. The load ratio is 39.2%, and the averaged unit COP and system COP are estimated to be 7.25 and 6.13 respectively. The heating COP is affected by the load ratio rather than water temperature. The COP is increased for 20%~40% load ratio, while is decreased for 40%~60% load ratio. It is estimated that the compressor operation combination for 3 (two constant speed and one inverter) compressors is changed for the load ratio.

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A Preliminary Study on the Analysis Model of Energy System based on Fuel Cell for Apartment Houses (연료전지기반 공동주택 에너지시스템 분석모델에 관한 기초연구)

  • Lee, Hong-Cheol;Hwang, In-Ju
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.396-401
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    • 2003
  • In the present study, preliminary investigation were carried out by analysis of energy system(heat and electricity) based on phosphoric acid fuel-cell of 50 kW for eco-apartment houses. Analysis model were consisted of fuel cell energy system, secondary energy unit and residential building of 5 stories with 20 and 40 households. And the investigation results reviewed under load pattern of heat and electric power of the apartment houses. The results showed mismatch between the needed heat load pattern and output of fuel cell energy system. The mismatch rate were assessed about 10-180% of heat load for apartment houses with season. We found that secondary energy unit are needed in order to supply insufficient heat.

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Heat Transfer above Liquid Helium Surface in Cryostat (극저온용기 액체헬륨 표면 상부의 열전달 특성)

  • Choi, Yeon-Suk;Kim, Dong-Lak;Shin, Dong-Won
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.2
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    • pp.147-152
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    • 2011
  • The cryogenic cooling load from the top plate of cryostat to liquid helium surface, including wall conduction, thermal radiation and current leads, is investigated in a closed cryostat system for superconducting magnet. In general methods of load estimation, individual load is calculated separately, however they are actually coupled each other because of natural convection of helium vapor. Using relevant heat transfer analysis, we calculate cryogenic load with taking into account the effect of natural convection. Cryogenic load is under-estimated approximately 1% when the natural convection is ignored. The difference between actual cooling load and cooling load by individual calculation increases with supplying current.

A Study on Control Method of Thermal Storage Tank for Varying Thermal Load in Heat Pump Water Heater (열펌프 온수기의 부하 대응 축열조 제어에 관한 연구)

  • Nam, Hyun-Kyu;Bai, Cheol-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.4
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    • pp.330-335
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    • 2012
  • A characteristic behavior of the thermal storage tank for varying thermal load in heat pump water heater was studied. The control method was suggested and applied. By measuring the temperature within the storage tank, the heat pump was ON/OFF controlled. The appropriate measuring position and the size of heat exchanger gives the minimized power consumption of heat pump. As the length of heat exchanger increases, the temperature measuring position goes down of the storage tank and the power consumption increases.

ADPI Characteristics of a Line-Diffuser (라인-디퓨저의 ADPI특성에 관한 연구)

  • Lee, Jae-Heon;Cho, Young-Jin;Kang, Seok-Youn;Oh, Myung-Do
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.958-964
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    • 2001
  • It is difficult to apply a conventional selection guide for diffusers when the diffuser is installed in a perimeter zone, because the ADPI(Air Diffusion Performance Index) vs. T/L(Throw/Length) curve listed in conventional guide does not consider the perimetric heating load. The objective of this study is to evaluate the effect of the perimetric heating load on the ADPI and to propose a selection guide for proper diffuser when perimetric heating load exists. The velocity and temperature distributions and the ADPI value are obtained numerically with various heat load ratios and air flow rates. The ADPI values by numerical result were compared with existing experimental data to verify the method for evaluation of ADPI proposed in present study. In case of a high side wall diffuser, the ADPI decreased with increases of the flow rate on every heat load ratio of present study except 0.75. Also, the ADPI vs. T/L curves have been proposed for the heat load ratios of 0.25, 0.5, 0.75 to guarantee comport thermal environment when diffusers are installed in perimeter zone.

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A Study on Estimation of Cooling Load for Effective Control of Ice Thermal Storage System (빙축열 시스템의 효율적인 제어를 위한 냉방부하 예측에 관한 연구)

  • Yoo, Seong-Yeon;Han, Kyu-Hyun;Lee, Je-Myo;Han, Seung-Ho
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.2
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    • pp.128-136
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    • 2008
  • It is necessary to estimate the cooling load of the next day for effective control of ice thermal storage system. In this paper, new methodology is proposed to estimate the cooling load using design parameters of building and predicted weather data. Only six input parameters such as sensible heat coefficient and constant, latent heat coefficient and constant, maximum and minimum temperature are necessary to obtain hourly distribution of cooling load for the next day. Two benchmarking buildings(hospital and research institute) are selected to validate the performance of the proposed method, and the estimated cooling loads in hourly and daily bases are calculated and compared with the measured data for E hospital. The estimated results show fairly good agreement with the measured data for both buildings.

ADPI Characteristics of Line Diffuser in a Room with Perimetric Heating Load (측벽 부하가 존재하는 공간에 설치된 라인 디퓨져의 ADPI 특성에 관한 연구)

  • Cho Young-Jin;Kang Seok-Youn;Moon Jong -Sun;Lee Jae-Heon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.12
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    • pp.1204-1211
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    • 2004
  • It is difficult to apply a conventional selection guide for diffusers when the diffuser is installed in a perimeter zone, because the air diffusion performance index (ADPI) vs. throw/length (T/L) ratio curve listed in conventional guide does not consider the perimetric heating load through the walls. The objective of this study is to evaluate the effect of the perimetric heating load on the ADPI and propose a selection guide for a proper line diffuser when perimetric heating load exists. The velocity and temperature distributions and the ADPI values are obtained numerically with various heat load ratios and air flow rates. The velocity and temperature distributions and the ADPI values are analyzed by CFD in case of various heat load ratios and air flow rates. Also, ADPI was calculated by those results. The ADPI values by numerical results are compared with an existing experimental data to verify the method for the evaluation of ADPI proposed in a present study. In case of a line diffuser installed at the high side wall, the ADPI decreases according to the increases of the flow rate on every heat load ratio of the present study except 0.75. The ADPI vs. T/L ratio curves have been proposed for the heat load ratios of 0.25, 0.5, 0.75 to guarantee the comport thermal environment when diffusers are installed in perimeter zone.