다공질암에서의 Electric Heating법에 의한 하이드레이트 해리현상 및 가스유동 분석을 위한 실험연구

성원모,이호섭,양호준 한국화학공학회 2004 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.42 No.1

본 연구에서는 유전의 생산정 하부에서 열을 발생시키는 방법으로 적용되어 온 electric heating 법을 이용하여 다공질 저류암에서의 열전달 현상과 이에 따른 하이드레이트 해리현상을 규명할 수 있는 실험장비를 개발하였으며, 이를 이용하여 열주입 실험을 수행하였다. 열주입 실험을 통하여 열주입법에 따른 코어의 열전달, 하이드레이트 해리현상 및 해리된 가스와 물의 생산성을 분석하였다. 실험 결과, 열주입에 의하여 하이드레이트 해리현상이 촉진되고 주입된 열이 하이드레이트 해리뿐만 아니라 해리된 가스와 물의 유출에 의해 손실됨을 알 수 있었다. 열주입법에 따른 가스 생산추이를 분석한 결과, 주입되는 열이 많을수록 유출부족의 해리를 더욱 촉진시켜 초기의 생산성이 향상되는 것으로 측정되었다. 또한 연속열주입법은 초기 생산성은 양호하나 주입된 열량에 비해 생산되는 가스의 양이 작아 에너지 효율성은 낮은 것으로 나타났다. 반면, 예열법에 의한 해리실험시 예열시간에 따라 초기의 가스 생산량에만 크게 차이가 날 뿐 전체적인 가스 생산의 거동양성은 유사한 것으로 나타났다. In this study, an experimental apparatus has been designed and set-up to analyze the dissociating phenomena of hydrate in porous rock using electric heating method supplied at downhole. The electric heat injecting experiments have been performed to investigate the heat transfer within the core, the dissociating phenomena of hydrate, and the productivities of dissociated gas and water. These experiments were under constant heat injecting method as well as preheating methods. From the experimental results, it is seen that dissociation of hydrate is accelerated with heat. The injected heat is consumed for the dissociation and also it is lost together with outflow of the dissociated gas and water. From the investigation of gas producing behavior for various heat injecting methods, as the injected heat is greater dissociation is accelerated faster at outlet and hence the initial gas production becomes higher. Also, it is shown that the initial gas productivity under the constant heating method is better, however, the heat is low because of smaller amount of the produced gas comparing to the amount of heat injected. In the experiments of preheating method, it was seen that gas production only initial stage is different with the preheating time, but the producing behaviors of gas production are similar.

검정 초등과학 교과서에 도입된 액체에서 열의 이동 실험에 대한 교사와 학생의 인식과 선호도 분석

정예진,박일우 한국현장과학교육학회 2023 현장과학교육 Vol.17 No.4

연구에서는 2015 개정 교육과정에 의한 초등 5학년 과학 검정교과서 9종에 소개된 액체에서 열의 이동 실험에 대한 교사와 학생의 인식과 선호도를 분석하였다. 9종의 검정교과서에 제시된 액체에서 열의 이동 실험을 주요 열원과 액체의 종류 및 양에 따라 네 종류로 유형화하였다. 네 종류 실험을 대상으로 관찰의 편의성, 실험의 안전성, 학생의 흥미도, 실험 준비의 편의성 면에서 교사의 인식과 선호도를 조사하고, 교사가 높게 평가한 세 종류의 실험을 선정하였다. 학생들이 선정된 세 종류의 실험을 모두 체험하게 하고, 학생들의 인식과 선호도를 조사하였다. 학생들은 관찰의 편의성과 흥미도 면에서는 가스버너를 이용하여 비커의 가장자리를 가열하는 실험을 선호하였고, 실험의 안전성과 실험 준비의 편의성에서는 작은 플라스틱 용기를 뜨거운 물로 가열하는 실험을 높게 평가하였다. 가열 과정이 포함된 실험에서 교사와 학생 모두 관찰의 편의성을 가장 중요하게 고려하였다. 그러나 두 번째 중요한 요소로 교사는 실험의 안전과 준비의 편리성을, 학생은 실험의 흥미도와 준비의 편리성을 고려하는 것으로 조사되었다. In this study, the perceptions and preferences of teachers and students regarding heat transfer experiments in liquids, as introduced in nine kinds of certified science textbooks for 5th grade elementary school students according to the 2015 revised curriculum, were analyzed. Experiments on heat transfer experiments were categorized into four types according to the primary heat source and the type and amount of liquid. Perceptions and preferences of teachers regarding the convenience of observation, safety of experiments, students' interest, and ease of experiment preparation were surveyed for the four types of experiments. Based on the high ratings given by teachers, three types of experiments were selected. Students were allowed to experience all selected experiments and then their perceptions and preferences were also surveyed. In terms of convenience and interest in observation, students preferred conducting experiments by heating the edges of a beaker using a gas burner. The experiment involving the heating of a small plastic container with hot water received high ratings for safety and ease of experiment preparation. In experiments involving the heating process, both teachers and students considered convenience of observation as the most important factor. However, as the next important factor, it was investigated that teachers considered the safety and convenience of preparation for the experiment, while students considered their interest in the experiment and the convenience of preparation.

‘온도와 열’ 단원의 탐구활동에 참여한 초등학생들의 실험 수행 특성 및 어려움 분석

신정윤(Jung Yun SHIN),박상우(Sangwoo PARK) 한국물리학회 2024 새물리 Vol.74 No.5

이 연구에서는 초등학교 5학년 ‘온도와 열’ 단원의 열의 이동에 관련된 탐구활동에서 초등학생들의 실험수행 과정 특징과 어려움을 분석하였다. 초등학교 4–6학년 학생 12명에게 ‘온도가 다른 두 물질이 접촉할 때 두 물질의 온도 변화’에 관한 탐구활동과 ‘고체에서의 열의 이동’에 관한 탐구활동을 수행하게 한 후, 학생들의 실험 과정 녹화 자료, 연구자 관찰 노트, 학생 활동지, 사후 면담 자료를 수집하여 분석하였다. 연구 결과, 학생들은 ‘온도가 다른 두 물질을 접촉할 때 두 물질의 온도 변화 측정하기’ 실험에서 실험을 정교하게 수행하지 못했고, 실험 결과를 해석하여 개념을 획득하는데 어려움을 나타내었다. 또 ‘고체에서의 열의 이동’ 실험에서는 실험이 어렵지 않고 실험 시간이 부족하지 않았음에도 실험 오류를 나타냈고, 고체에서의 열의 이동에 관한 개념에 도달하지 못한 학생들이 있었다. 연구 결과를 바탕으로 실험 기구의 설치와 조작 과정에서 어려움 해결 방안, 실험 활동에 필요한 세부 과정 서술의 필요성과 서술 방안, 실험 수행 능력 향상을 위한 학습 지도 필요, 그리고 두 탐구활동의 난이도와 과학 개념 이해에서의 문제점과 해결 방안에 대해 논의하였다. This study analyzed the characteristics and difficulties of elementary school students’ experiment processes in inquiry activities related to heat transfer in the ’Temperature and Heat’ unit of the 5th grade elementary school curriculum. After conducting inquiry activities with 12 students from 4th to 6th grade, we collected and analyzed students’ experiment process videos, researcher observation notes, student activity sheets, and post-interview data. The results showed that students encountered difficulties in conducting experiments precisely and interpreting the results to understand the concepts. Additionally, in the experiment on heat transfer in solids, students experienced experimental errors despite the experiment not being particularly difficult or time-constrained, and some students did not fully understand the concept of heat transfer in solids. Based on the research findings, we discussed solutions for addressing difficulties in setting up and operating experimental apparatus, the need for detailed description of experimental procedures for enhancing experimental skills.

흡연경험이 있는 청소년들의 일반담배와 가열담배의 복합흡연경험 영향요인: 제14차 청소년건강행태조사를 기반으로

빈성오 한국학교·지역보건교육학회 2019 한국학교지역보건교육학회지 Vol.20 No.2

Objectives: The purpose of this study is to understand the factors affecting the dual smoking experience of conventional and heat-not-burn tobacco among adolescents with smoking experience. Methods: The study selected 8,691 people with experience in smoking. Data analysis used SPSS 25.0. Logistic regression was performed to identify the factors affecting the dual smoking experience. Results: In this study, the dual smoking experience rate of conventional and heat-not-burn tobacco was 16.3%. The dual smoking experience rate was 5.09 times higher than the number of smokers among friends. The lower the smoking age, the higher the smoking rate, and the longer the smoking days, the higher the dual smoking rate of heat-not-burn cigarettes. Conclusion: We need a peer-to-peer group arbitration program rather than a separate anti-smoking arbitration program for smokers Objectives: The purpose of this study is to understand the factors affecting the dual smoking experience of conventional and heat-not-burn tobacco among adolescents with smoking experience. Methods: The study selected 8,691 people with experience in smoking. Data analysis used SPSS 25.0. Logistic regression was performed to identify the factors affecting the dual smoking experience. Results: In this study, the dual smoking experience rate of conventional and heat-not-burn tobacco was 16.3%. The dual smoking experience rate was 5.09 times higher than the number of smokers among friends. The lower the smoking age, the higher the smoking rate, and the longer the smoking days, the higher the dual smoking rate of heat-not-burn cigarettes. Conclusion: We need a peer-to-peer group arbitration program rather than a separate anti-smoking arbitration program for smokers

실험을 통한 창호시스템에 의한 냉난방부하 및 냉난방에너지 소비 특성 평가

안민철(Ahn, Min-Chul),정창호(Jeong, Chang-Ho),김태현(Kim, Tae-Hyun),김화국(Jin, Hua-Guo),박재성(Park, Jae-Sung),여명식(Yeo, Myoung-Souk),김광우(Kim, Kwang-Woo) 한국건축친환경설비학회 2012 한국건축친환경설비학회 학술발표대회 논문집 Vol.2012 No.10

To predict the thermal performance of the window systems generally is calculated based on the glass U-value. However, there is a limit to predict the thermal performance with a glass because the window system consists of the glass, frame, and other parts. This study analyzes a difference between prediction of theoretical value based on the glass U-value and actual value through window systems experiment. To achieve this purpose of study, we calculated maximum heating and cooling loads based on each window systems glass U-value and we built laboratory to adjust the room temperature conditions. This experiment analyzed moment of maximum heating and cooling loads by window systems and heating and cooling energy consumption reduction effect for loads handling.

태양열 및 보일러이용 온수난방 시스템에 관한 실험적 연구

박윤철(Y. C. Park ),김현석(H. S. Kim ),류남진(N. J. Ryu ) 한국동력기계공학회 2009 한국동력기계공학회 학술대회 논문집 Vol.2009 No.6

The solar energy is limitless and pollution-free natural energy; however, the solar energy has not been utilized extensively due to its low density and restriction of availability. This study was conducted to analyze operating characteristic of a solar assisted heating system for hot water supply and panel heating of a house. The main part of the system is a thermal storage tank which was designed to store energy that obtained from solar collectors and a burner. The heat exchanger is located on bottom of the storage tank which supplies solar energy to the water in the storage tank and is connected directly to the solar collector. As an additional heat source, a burner was inserted to the top of the storage tank and supplies energy to water in the storage tank through indirect contact of the fire frame and stack flue. And also a small tank for hot water heating was attached at inside of the thermal storage tank. The water in the tank is heated by the water in the thermal storage tank. As results, if design temperature of the boiler is increased, the efficiency of system is decreased. When the system uses hot water, system performance is decreased as increasing of the warm water usage. The developed system can be used as main heating equipment to the residential with the panel heating.

Variation in the angular heat flux of the oxide pool with Rayleigh number

Park, Hae-Kyun,Kim, Su-Hyeon,Chung, Bum-Jin Pergamon Press 2017 Annals of nuclear energy Vol. No.

<P><B>Abstract</B></P> <P>The experiments were performed on natural convection heat transfer of an oxide pool using a three-dimensional hemispheric test rig. To achieve a high <I>Ra</I>, mass transfer experiments were conducted based on the analogy between heat and mass transfers. A CuSO<SUB>4</SUB>-H<SUB>2</SUB>SO<SUB>4</SUB> electroplating system was used. The range of modified <I>Ra</I> was from 8.63×10<SUP>12</SUP> to 1.45×10<SUP>15</SUP> with a cooling top plate and from 2.44×10<SUP>12</SUP> to 4.73×10<SUP>14</SUP> with an insulating top plate. The <I>Sc</I> was 2014. The mean and local <I>Nu</I> values of the lower head and top plate were measured and compared with previous reports. The total <I>Nu</I> values agreed well with existing studies, within 10%. The split ratio of the heat fluxes between the lower head and top plate was affected by the difference in the <I>Pr</I>. Heat flux distributions at the lower head and top plate were not affected significantly by the modified <I>Ra</I>, except for the uppermost location of the lower head. The heat flux distribution at the lower head was not affected by the top cooling condition. Heat transfer correlations for mean and local <I>Nu</I> values were developed from the experimental results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Natural convection of oxide pool depending on the Rayleigh number was studied. </LI> <LI> High buoyancy was achieved with compact test rig adopting mass transfer experiment. </LI> <LI> Trends of total Nusselt number were similar to existing studies. </LI> <LI> Split ratio of the heat flux between lower head and top plate was affected by Prandtl number. </LI> <LI> Presence of top cooling did not yield significant change on heat flux distribution. </LI> </UL> </P>

2015 개정 검정교과서에 제시된 기체에서 열의 이동 실험에 대한 초등교사와 초등학생의 선호도 조사

박아영,심예지,박일우 한국현장과학교육학회 2023 현장과학교육 Vol.17 No.3

The 9 types of experiments exploring heat transfer in gases in the 5th grade ‘Temperature and Heat’ chapter of the certified elementary science textbooks according to the 2015 revised curriculum were classified into four types. A survey was conducted on 60 elementary school teachers to find out the teachers' preferences for four types of experiments related to heat movement in gases. Reflecting the survey results, three types of experiments were selected to explore heat movement in gases and were then applied to elementary science classes. After applying it to science classes, students' preferences were also surveyed. As a result, both teachers and students answered that they prefer experiments that the results could be clearly observed. Teachers preferred experiments using color changes of thermochromic stickers as an easy-to-understand experiment about heat movement in gases, but students most preferred experiments that they could observe the movement of incense smoke.

서모 사이펀식 히트파이프를 이용한 건식 바닥난방시스템의 제안 및 성능평가

이정재,김용경,최석용 대한건축학회 2005 대한건축학회논문집 Vol.21 No.3

This research proposes a prefabricated floor heating panel system which is optimized through the real-scale model experiment. This system is alternated Cross Linked Poly-ethylene Pipe (XL pipe) by using thermo siphon type heat pipe that is used for a heat transfer tool in machine field. When applied this system to floor heating, floor surface and room temperature, operation form of boiler etc. are enough scope to apply to floor heating. Merely, the change of temperature of floor surface is serious because of no heat storage layer. This is the point to supplement through the optimization research hereafter. When we examine the data which is gained through the operating for 37days in winter, energy consumption characteristic between two systems turned at below zero 1.5℃. That is, heat pipe system was construed that energy expenditure of XL system is much more in lower than below zero 1.5℃.

온수배관에 의한 온실 내부의 온도변화

윤용철,신익수,배승범,김현태,최진식,서원명 경상대학교 농업생명과학연구원 2012 농업생명과학연구 Vol.46 No.2

본 연구는 유가상승에 따른 온실의 경영비 절감과 적설지역의 적설재해를 경감시키기 위하여 온수배관을 이용한 난방효과 및 온실곡부의 온도 상승효과를 구명하고자 수행되었다. 전체적으로 실험구의 온도가 대비구 보다 약 2.0~6.0℃정도 높게 나타났다. 천창부직포를 개방한 경우, 최저온도가 약 3.0~12.0℃범위로 나타나 적극적인 난방을 하게 되면 적설피해도 어느 정도 예방할 수 있을 것으로 판단되었다. 온실 내부의 높이별 온도 차이는 미미한 것으로 나타났다. 재배작물에 따른 온실의 최대난방부하는 각각 약 37,000 kcal·h-1 및 41,700 kcal·h-1정도이었다. 실험기간동안 최저 외기온 -11.9~4.0℃ 범위에서 설정온도별 발열량은 95,000~322,000 kcal 정도로서 시간당 6,050~20,900 kcal·h-1정도의 범위에 있었고, 최대난방부하와 비교하면 약 15~56%정도의 난방에너지를 공급할 수 있을 것으로 나타났다. 그리고 실험기간동안 전체 발열량과 소비전력량은 각각 2,629,025 kcal 및 677.3 kWh이었다. 화석연료인 경유로 난방 할 경우, 실험기간동안 소요되는 소비량은 291L 정도이었고, 비용은 331,700 won인 것으로 나타났다. 전력사용에 대한 총비용은 24,400 won정도로서 경유 소비 비용의 7.5%정도로 나타났다. 또한 전체 소비전력량을 에너지로 환산하면 약 582,200 kcal이고, 이 에너지는 전체 발열량의 약 22%에 불과하였다. This study was performed to obtain a heat saving effect and enhance the efficiency of a greenhouse by using a hot water piping in order to minimize the operating costs of a greenhouse as oil prices continue to rise. This method also reduces the likelihood of accidents caused by snowdrifts in regions with heavy snowfall. In general, the experimental plot was 2.0~6.0℃ higher than the control plot. When the skylight felt was opened, the minimum temperature was in the range of 3.0~12.0℃. Therefore, we judged that damage caused by snowdrifts may be prevented partly by active heating. The temperature difference inside of the greenhouse by height was insignificant. The maximum heating load of the greenhouse according to crop was respectively about 37,000 kcal·h-1 and 41,700 kcal·h-1. During the experiment, the heat value of each designed temperature in the range of the minimum ambient temperature -11.9~4.0℃ was about 95,000~322,000 kcal and it was in the range of 6,050~20,900 kcal·h-1. If it is compared with the maximum heating load, it can be shown that about 15~56% of the heating energy can be supplied. The total heat value and the amount of power consumption were 2,629,025 kcal and 677.3 kWh respectively during the experiment. If it is heated with diesel, a fossil fuel, the consumption during the experiment was 291 L and the cost was 331,700won. Total cost of using electric power was about 24,400 won and it is shown that it is about 7.5% of the cost of diesel consumption. Also, if the total amount of power consumption is converted into energy, it is approximately 582,200 kcal and the energy was just about 22% of the total heat value.