• Title/Summary/Keyword: Temperature condition

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Effects of decay heat and cooling condition on the reactor pool natural circulation under RVACS operation in a water 2-D slab model

  • Min Ho Lee ;Dong Wook Jerng ;In Cheol Bang
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1821-1829
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    • 2023
  • The temperature distribution of the reactor pool under natural circulation induced by the RVACS operation was experimentally studied. According to the Bo' based similarity law, which could reproduce the temperature distribution of the working fluid under natural circulation, SINCRO-2D facility was designed based on the PGSFR. It was reduced to 1 : 25 in length scale, having water as a simulant of the sodium, which is the original working fluid. In general, temperature was stratified, however, effect of the natural circulation flow could be observed by the entrainment of the stratified temperature. Relative cooling contribution of the upper plenum (narrow gap) and lower plenum was approximately 0.2 and 0.8, respectively. In the range of decay heat from 0.2% to 1.0%, only the magnitude of the temperature was changed, while the normalized temperature maintained. Boundary temperature distribution change made a global temperature offset of the pool, without a significant local change. Therefore, the decay heat and cooling boundary condition had no significant effect on temperature distribution characteristics of the pool within the given range of the decay heat and boundary temperature distribution.

Application of 5678SMRT Real-time Monitoring system (도시철도 실시간 모니터링 시스템 적용 사례)

  • Yoon, Jae-Kwan;Park, Jong-Hun;Kim, Ki-Chun
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.737-747
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    • 2011
  • 5678SMRT has installed various sensor for operating conditions(field of electric, facilities, signal, communication equipment and track) and environment of Every Function Room for remotely detecting and monitoring. Installed sound sensor for analyzed after remotely heard the noise of every equipment at Every Function Room and temperature sensor for check the temperature condition of Every Function Room. Additional installed voltage sensor in signal equipment room for monitoring RF track-circuit's voltage condition. Installed displacement sensor at The Chungdam bridge's railway for measuring and monitoring track displacement caused by temperature change and Pan/Tilt camera at sub-station and drainage for remotely field monitoring. Installed sensor for each equipment's operating condition and failure at Every Function Room then periodic check of workforce turned to around-the-clock surveillance by sensor therefore improvement of operating equipment. SMRT is lots of prevent a failure by Immediately detect of precondition of equipment failure by analyzed the sensor data. If the occurrence of an failure, become detected Immediately so possibility correct diagnosis and order by remotely field check by installed camera and sound sensor at field.

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Operation Condition and Characteristics for Treatment of Piggery Slurry using Thermophilic Aerobic Oxidation System (축산분뇨 처리에 적용된 급속액상부숙기술(TAO system)의 운전특성과 운전조건)

  • 이명규;이원일
    • Journal of Animal Environmental Science
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    • v.6 no.3
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    • pp.161-168
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    • 2000
  • The study exploited TAO system for the treatment of piggery slurry and aimed to draw characteristics and conditions of the reactor by differentiating the number of air input pump and foam cutter. The results are: 1. Under different operation condition, Run-3 with three air input pumps and four foam cutters showed the highest efficiency in the change of water level and temperature; 40-70cm and 45-55$^{\circ}C$, respectively. 2. Evaporation volume in Run-3 was the highest; 55.5l/$m^2$ . day in Run-1, 75.0/$m^2$ . day in Run-2, and 120.3/$m^2$ . day in Run-3. 3. Throughout the experimental period, temperature inside the reactor was maintained at around 5$0^{\circ}C$, regardless of seasonal temperature changes.

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A Study on the Thermal Shock Characteristics of the Rocket Nozzle Material (로켓 노즐 재료의 열충격특성에 관한 연구)

  • Lee, Jang-Won;Lee, Young-Shin;Kim, Jae-Hoon;Kim, Seung-Joong
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.562-566
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    • 2004
  • Thermal shock is a physical phenomenon that occurs in the condition of the exposure of a rapidly large temperature and pressure change of in the quenching condition of material. The rocket nozzle is exposed to high temperature combustion gas, it may have failure and erosion deformation. So, it is important to select a suitable material having excellent thermal shock properties and evaluate these materials in rocket design. In this study, the temperature gradient and crack initiation of rocket nozzle material is investigated using by FEM under thermal shock condition. This is very important information in the design process of thermal structure.

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The Analysis of Volatile Organic Compounds in Water by Using the Purge-and-Trap and the Gas Chromatography/Mass Selective Detector with Modified Indirect Coupling (퍼지-트랩장치와 변형된 간접 결합기를 부착한 기체크로마토그래피/질량 선택성 검출기를 이용한 물중의 휘발성 유기화합물의 분석)

  • 정영자
    • The Korean Journal of Food And Nutrition
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    • v.12 no.2
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    • pp.191-191
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    • 1999
  • A Purge & Trap Concentrator was used to analyze various volatile organic compounds(VOCs) in wat-er. The object of this study was to observe the purge efficiency of 40 VOCs in water according to the change of parameters (purge time drypurge time sample temperature) and to determine the optimum condition for VOCs using the purge & Trap concentrator interfaced with a narrow capillary connected to a gas chromatography/mass spectrometry. The optimum condition of purge and trap is as follows: purge time at 11min drypurge time at 5min sample temperature at 6$0^{\circ}C$ at constant purge flow (40mol/min) constant desorption flow(20ml/min) desorption temperature(2$25^{\circ}C$) and desorption time (1min) At this analytical condition the detection limits of VOCs was in the range of 0.1~0.5$\mu$g/ml and the purge efficiency of each compound was over 70%.

Frozen and Melting Characteristics of Urea-aqueous Solution for Urea-SCR System by Circulation of Engine Coolant (엔진 냉각수 순환에 의한 urea-SCR 시스템용 요소수의 동결 및 해동 특성)

  • Choi, B.C.;Kim, Y.K.;Kim, H.N.
    • Journal of Power System Engineering
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    • v.15 no.4
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    • pp.42-47
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    • 2011
  • The purpose of this study is to investigate the best melting condition with various winding number of a heating pipe, supplying quantity of engine coolant and coolant temperature at the inlet of the heating pipe. Also, it is to suggest getting method of an appropriate quantity of the agent for the urea-SCR system within 10 minutes. For this matter, this study identifies the temperature distribution of inside of urea-tank while it is frozen at the low temperature condition, and suggests the best melting condition of the frozen urea within 10 minutes. From the results, it was found that 2L of melted urea was obtained by the coolant flow rate of 200L/hr at $70^{\circ}C$ for 10 minutes from the start of engine operating.

Feasibility study of ground source heat pump system according to the local climate condition (지역 기후 특성에 따른 지열시스템의 도입경제성 차이에 관한 연구)

  • Nam, Yujin
    • KIEAE Journal
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    • v.14 no.4
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    • pp.127-131
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    • 2014
  • The ground source heat pump (GSHP) system is a kind of the temperature differential energy system using relatively stable underground temperature as heat source of space heating and cooling. This system can achieve higher performance of system than it of conventional air source heat pump systems. However, its superiority of the system performance is different according to installation location or local climate, because the system performance depends on the underground condition which is decided by annual average air temperature. In this study, in order to estimate the feasibility of the ground source heat pump system according to the local climate, numerical simulation was conducted using the ground heat transfer model and the surface heat balance model. The case study was conducted in the condition of Seoul, Daejeon, and Busan, In the result, the heat exchange rate of Busan was 34.33 W/m as the largest in heating season and it of Seoul was 40.61 W/m as the largest in cooling.

A Study on Thermal Stress in T/G Wall of Containment Building (격납건물 텐던갤러리 벽체의 온도응력에 대한 연구)

  • 김진근;양은익;박영진;송영철;방기성
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04a
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    • pp.193-198
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    • 1998
  • In this study, the change of concrete temperature, strain and thermal stress were measured by using the embedded type concrete gauges in tendon gallery wall of containment building. A finite element analysis was performed to clarify the thermal behavior of concrete. The analytic and test results were investigated to improve the validity of analytic method. According to the test results, concrete temperature, strain and thermal stress were strongly affected by measuring point and environment condition of member. And the thermal stress was developed in the member which was not demoulded at early ages. This is caused by the change of internal temperature and restrained condition. A finite element effectively interpreted the test results by estimating the concrete properties and the site condition.

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Study on frost Generation and Defrosting Mechanism on Evaporating Tubes for Refrigerator and Air condition industries (냉동공조용 관군에서의 서리발생 및 제상 메커니즘에 관한 연구)

  • Jee, Jae-Hoon;Kim, Chang-Bok;Mun, Sung-Bae;Oh, Cheol
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.11a
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    • pp.234-235
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    • 2005
  • In this experiment study, to acquire elementary data for explaining to generate frost layer in the fin - tube evaporator. the experiment condition is to supply air on 0.3m/s, 0.6m/s, 0.9m/s and inlet air temperature is 15$^{circ}C$, 20$^{circ}C$, 25$^{circ}C$ , supplied air relative humidity is 70%, 80, 90%. And brine temperature in the copper tube was kept -15$^{circ}C$ because, generally cooling temperature range is constantly -15$^{circ}C$ in the heat exchanger for air conditioning system. in conclusion, through this experiment, we did compare with frost layer and frost thickness in each condition and examine these data

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Thermal Environment Analysis of a Room in Accordance with Ventilation Condition with Multi-Heat Sources (다수의 열원을 가지는 공간에서의 환기 조건에 따른 열환경 해석)

  • Kim, Jae-Jung;Son, Young-Gap;Chang, Seog-Weon;Ryu, Dong-Su
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.199-204
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    • 2000
  • This paper reports a thermal environmental analysis of a room in accommodated with multi-heat sources according to ventilation condition. Two case modification have been investigated to obtain the lower temperature distribution in the room. The temperature distribution of the original room were found about $25{\sim}35^{\circ}C$. As a result, the use of, three ventilating fans and two electric fans are useful for room ventilation respectively, and using two electric fan is more recommendable in side of economical efficiency.

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