• Title/Summary/Keyword: New Effective temperature

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An Experimental Study on the Thermal Performance Measurement of Standing Column Well type Borehole Heat Exchanger (스탠딩컬럼웰형(SCW) 지중열교환기의 열성능 측정에 관한 실험적 연구)

  • Lee, Sanghoon;Choe, Yongseok;An, Kunmuk
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.122.2-122.2
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    • 2010
  • Knowledge of ground thermal properties is most important for the proper design of BHE(borehole heat exchanger) systems. The configure type, pipe size and thermal performance of the BHE is highly dependent on the ground source heatpump system-efficiency and instruction cost. Thermal response tests with mobile measurement devices were developed primarily for in-situ determination of design data for Standing Column Well apply. The main purpose has been to determine in-situ values of effective ground thermal conductivity and thermal resistance, including the effect of ground-water flow and natural convection in the boreholes. The test rig is set up on a some trailer, and contains a sub-circulation pump, a boiler, temperature sensors, flow meter and a data logger for recording the temperature and circulation fluid flow data. A constant heating power is injected into the SCW through the test rig and the resulting temperature change in the SCW is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective in-situ values of rock thermal conductivity and thermal resistance of SCW.

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An Experimental Study on the Thermal Performance Measurement of Large Diameter Borehole Heat Exchanger(LD-BHE) for Tripe-U Pipes Spacer Apply (3중관용 스페이서를 적용한 대구경 지중열교환기의 성능측정에 관한 연구)

  • Lee, Sang-Hoon;Park, Jong-Woo;Lim, Kyoung-Bin
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.581-586
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    • 2009
  • Knowledge of ground thermal properties is most important for the proper design of large scale BHE(borehole heat exchanger) systems. The type, pipe size and thermal performance of the BHE is highly dependent on the ground source heatpump system-efficiency and instruction cost. Thermal response tests with mobile measurement devices were developed primarily for insitu determination of design data for large diameter BHE for triple-U spacer apply. The main purpose has been to determine insitu values of effective ground thermal conductivity and thermal resistance, including the effect of ground-water flow and natural convection in the boreholes. The test rig is set up on a some trailer, and contains a circulation pump, a inline heater, temperature sensors, flow meter, power analysis meter and a data logger for recording the temperature, fluid flow data. A constant heat power is injected into the borehole through the tripl-U pipes system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance of large diameter BHE for spacer apply.

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Study on Economic analysis and Dessemination Policy of Unused Energy (미활용에너지의 경제적 효과 및 보급지원방안 연구)

  • An, Hyung-Jun;Baek, Sung-Kwon;Heo, Eunn-Yeong
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.95-98
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    • 2008
  • Temperature difference energy is a good energy source replacing the fossil fuels. In the study, we classified the temperature difference energy as 4 types by the source & using method. For the understanding economic property of temperature difference energy, we tried simle economic analysis. As the result, Pay back period of 4 case of the temperature difference energy are from 1.23 to 12.65 years. Major factors influenced economic effect are operation time and energy user distance from the temperature difference energy source. If we can select optimal capacity and look for more effient energy users, Temperature difference energy play a important role of replacing fossil energy. So, for dess emination of temperature difference energy, we suggest that temperature difference energy must be included in renewable energy. Applying the effective methods among various promotion program of renewable energy policy, utilization of temperature difference energy could be activated.

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Reconstruction of Thermodynamics by the Concept of Available Energy (II) - Thermodynamics of Real World - (가용 에너지에 의한 열역학의 재구성 (II) - 실제세계 열역학 -)

  • Jung, Pyung-Suk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.12
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    • pp.1573-1581
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    • 2004
  • Thermodynamic principles are described with a new point of view. In present study, the interaction between two systems is focused instead of the behavior of a system in conventional thermodynamics. The state change of a system cannot occur by itself but it is the result of the interaction between systems. However, the interaction itself is also the result of another kind of interaction, the interaction between two interactions. To reconstruct thermodynamics with such a point of view, the reversible world is imagined, in which conservations and measurements are discussed. There exists a conserved quantity for each mode of reversible interaction. The conserved transferring quantity in the interaction between interactions is the effective work, which is supposed to be measurable and conserved in reversible world. Effective work is the primary concepts of energy. It is the key factor to explain measurements, energy conservation and energy dissipation. The concepts developed in reversible world are applied to the real world in which irreversible phenomena may occur. Irreversibility is the result of effective energy dissipation, in which effective work irreversibly changes into entropy. A quantitative relation between the disappearing effective work and the generated entropy is dissipation equation which is given by experiments. A special temperature scale to give a very simple type of the dissipation equation is the absolute temperature scale, which gives the conventional conservation of energy.

The Effect of the Materials of an Outer Wall and the Paved Street on Human Thermal Comfort in a Housing Complex in Pohang City (포항시의 집합 주거공간에 있어서 외장재 및 도로 구성재료가 인체 온열 쾌적성에 미치는 영향)

  • Jeong, Chang-Won;Kim, Kyung-Dae;Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.3
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    • pp.319-327
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    • 2001
  • The objective of this study is to clarify the effect of thermal radiation environments on human thermal comfort, depending on different canyon types and surface materials on the human thermal comfort in a housing complex in Pohang city, Korea. For this purpose, the operative temperature and new effective temperature were calculated based on the modified mean radiant temperature of canyon models variated by the existence of direct radiation existence, surface materials, and the width and length of the street spaces in a housing complex. These indices for the canyon have been calculated from the meteorological data of Pohang city, which include air temperature, relative humidity, air velocity, global solar radiation and cloud. And the monthly averages of these climate factors measured at noon have been used. The results are as follows: (1) It is revealed that the short-wave radiosity reached the human body is affected by direct solar radiation and surface materials, and the long-wave radiosity by canyon types. (2) The existence of direct solar radiation, the kinds of surface materials and canyon types affect operative temperature($OT_n$) and new effective temperature($ET^*{_n}$). (3) The analysis of the human heat balance in the canyon indicates that the influence of radiation on human body is marc likely to be affected by the existence of direct solar radiation on human model.

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Field Measurements of Indoor Air Quality in Apartment Units at Medium-size Cities (중소도시 공동주택의 실내공기질(새집증후군) 실측에 관한 연구)

  • Yoon, JaeOck
    • KIEAE Journal
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    • v.10 no.4
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    • pp.81-86
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    • 2010
  • The main sources of the new house syndrome(sometimes it called sick building syndrome) are a concentration of formaldehyde (HCHO) and a concentration of total volatile organic compounds(TVOC). I had field measurements of indoor air quality in the apartment unit at medium-size cities(Y city, C city). I measured indoor air temperature, HCHO concentration in 16 units, TVOC concentration in 6 units and air tightness in 7 units. And I measured outdoor air quality, HCHO concentration and TVOC concentration. Mean concentration of HCHO was $357{\mu}g/m^3$(2006 standard=$120{\mu}g/m^3$), mean concentration of TVOC was $3,092{\mu}g/m^3$ and mean effective air leakage area was 193 cm2. There was a close relation between the indoor air temperature and HCHO concentration, between the indoor air temperature and TVOC concentration. Air tightness also had relation.

Experimental device for studying natural GH-bearing specimens (GH 함유 자연시료 실험 연구 셀 제작 및 활용사례)

  • Lee, Joo-Yong;Lee, Jae-Hyung;Lee, Min-Hui
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.703-704
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    • 2009
  • Natural gas Hydrate is an ice-like crystal containing natural gas it. Natural gas hydrate is studied as a new energy resource and a factor for seafloor slope stability and global warming. The unique pressure and temperature stability conditions of natural gas hydrate have challenged the research efforts. In this study, a new tool to study hydrate-bearing sediments and the preliminary results are introduced. The device can sustain 20MPa of the fluid pressure and apply 5MPa of the vertical effective stress under the temperature control. Cell can be scanned by X-ray CT scanner and also has the capability of multi-sensor data acquisition. Preliminary results suggests various application of the cell to hydrate-bearing research.

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Simulation of aquifer temperature variation in a groundwater source heat pump system with the effect of groundwater flow (지하수 유동 영향에 따른 지하수 이용 열펌프 시스템의 대수층 온도 변화 예측 모델링)

  • Shim, Byoung-Ohan;Song, Yoon-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.701-704
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    • 2005
  • Aquifer Thermal Energy Storage (ATES) can be a cost-effective and renewable geothermal energy source, depending on site-specific and thermohydraulic conditions. To design an effective ATES system having influenced by groundwater movement, understanding of thermo hydraulic processes is necessary. The heat transfer phenomena for an aquifer heat storage are simulated using FEFLOW with the scenario of heat pump operation with pumping and waste water reinjection in a two layered confined aquifer model. Temperature distribution of the aquifer model is generated, and hydraulic heads and temperature variations are monitored at the both wells during 365 days. The average groundwater velocities are determined with two hydraulic gradient sets according to boundary conditions, and the effect of groundwater flow are shown at the generated thermal distributions of three different depth slices. The generated temperature contour lines at the hydraulic gradient of 0.00 1 are shaped circular, and the center is moved less than 5m to the groundwater flow direction in 365 days simulation period. However at the hydraulic gradient of 0.01, the contour center of the temperature are moved to the end of boundary at each slice and the largest movement is at bottom slice. By the analysis of thermal interference data between two wells the efficiency of the heat pump system model is validated, and the variation of heads is monitored at injection, pumping and no operation mode.

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The Effect of Gasoline Engine Oil Degradation and Piston Temperature on Carbon Deposit Formation; Part I-Characteristics of deposit formation on gasoline engine (엔진 오일 열화와 피스톤 온도가 카본 디포짓 형성에 미치는 영향 Part I-가솔린 엔진의 디포짓 형성 특성)

  • 김중수;민병순;이두순;오대윤;최재권
    • Tribology and Lubricants
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    • v.13 no.4
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    • pp.33-39
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    • 1997
  • In order to establish a new temperature criterion to prevent the pistons from ring sticking due to deposit formation, bench test and engine test were performed. The effects of oil degradation and temperature on deposit formation was studied by a modified panel coking test. Oil degradation was analyzed by FTIR. Oil oxidation and nitration were selected as a factors to evaluate oil degradation. Bench test results show that oil oxidation is more effective to the deposit formation than oil nitration. And the temperature increase accelerates deposit formation and deposit formation increase rapidly above 26$0^{\circ}C$. Especially, in case of degraded oil, the deposit formation increases so rapidly that ring sticking can occur. The effect of piston temperature on the deposit formation was confirmed by engine test.

Clinical study about 62 cases of psoriasis patient using pyretotherapy (피레토세라피를 이용(利用)한 건선환자(乾癬患者) 62명(名)에 대(對)한 임상보고(臨床報告))

  • Kang, Jae-Chun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.25 no.4
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    • pp.35-44
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    • 2012
  • Objectives : This study was aimed to evaluate the treatment effect of psoriasis patient using pyretotherapy. Methods : The clinical study was performed using retrospective observational research method. Treatment method was pyretotherapy that optimized core temperature through herbs therapy, food therapy, excercise and life style change. In other aspects, pyretotherapy is skin cure therapy that rise core temperature, down skin temperature and open sweat gland. Results : 1. 40s years showed the most coming of clinic in the distribution of age of psoriasis patient. 2. Board type showed the most number in the classification of psoriasis. 3. Pyretotherapy was very effective results in psoriasis patient treatment. 4. Pyretotherapy showed effects of rising axillary temperature and moving facial high skin temperature toward abdominal portion. Conclusions : The author is able to say that it is possible for pyretotherapy to become new skin therapy for many skin disease, especially psoriasis.