• Title/Summary/Keyword: 대체 에너지

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Consideration about Ozone Generation in the Treatment Room While Treating a Patient (방사선 치료 시 치료실 내에서 발생하는 오존에 관한 고찰)

  • Kwak, Yong-Kuk;Yoon, Il-Kyu;Lee, Jae-Hee;Yoo, Suk-Hyun
    • The Journal of Korean Society for Radiation Therapy
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    • v.21 no.2
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    • pp.75-82
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    • 2009
  • Purpose: Measure the ozone level in the treatment room while treating a patient so want to know the degree of contamination caused by ozone occurrence. Materials and Methods: Use the linear accelerator (Clinac 21EX, Varian, USA) with the ozone meter (series-200, aeroQual, New Zealand) and water phantom (Wellhofer, IBA, Germany) is irradiated the radiation so that measured the ozone generation level according to MU, dose-rate, SSD, field size, energy, delay time and put the ozone meter in the treatment room actually while treating a patient so measured the daily ozone level variation. Results: While irradiating the radiation, degree of ozone contamination wasn't affected by the energy but mostly in case of electron beam, ozone level was higher than photon beam. The higher dose-rate (0.016~0.025 ppm/hr), the farther SSD (0.018~0.030 ppm/hr), the wider field sizes (0.016~0.025 ppm/hr), the more MU (0.018~0.046 ppm/hr), it occurred high ozone level. Ozone decrement according to delay time changed the background level (0.016 ppm/hr) after elapsed time of 10 minutes from irradiating radiation. And daily ozone occurrence level in the treatment room was below ozone standard level 0.1 ppm/hr (average:0.06 ppm/8 hr) but it could confirm that ozone generation level was included the level (max:0.038 ppm/hr) above 0.02 ppm/hr which patient could perceive. Conclusion: Through ozone level according to variation of certain conditions, actually in the treatment room ozone generation level didn't damaged to patients or workers. Commonly peoples think that ozone was harmful gas but it thought that small amount of ozone generation level while treating a patient was beneficial in the treatment room through air purge action of pathogenic germ or virus sterilization.

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Study on the correlation between nutrition knowledge, dietary attitudes of guardians, and nutritional status of infants and toddlers - Nutrition-Plus program in Jeonju (보호자의 영양지식 및 식생활태도와 영유아의 영양상태와의 관계연구 - 전주지역 영양플러스 참여자를 중심으로)

  • Song, Eun Young;Rho, Jeong Ok
    • Journal of Nutrition and Health
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    • v.51 no.3
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    • pp.242-253
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    • 2018
  • Purpose: The purpose of the study was to identify the nutrition knowledge, dietary attitudes of guardians, and nutritional status of infants and toddlers as well as the relationships between these variables. Methods: The participants were selected among applicants for low-income family financing provided by the government and included 115 infants and toddlers as well as their guardians. Demographic data, nutrition knowledge, dietary attitudes, and nutrition intakes were assessed using a self-administered questionnaire, biochemical examination, and 24 Hour-Recall method. Results: The score for guardians' nutrition knowledge was 12.97 points of a possible 15, and the score for dietary attitudes was 53.38 points of a possible 75. The nutrition knowledge and dietary attitudes showed significant differences by education level (p < 0.05) and family structure (p < 0.05). Energy intakes of subjects aged 6 ~ 24 months and over 25 months were lower than the DRI for Koreans. The intakes of carbohydrates, protein, and fat of subjects aged 6 ~ 24 months and over 25 months showed no significant differences by level of nutrition knowledge or dietary attitudes. The intake of Ca of subjects aged over 12 months showed significant differences by level of nutrition knowledge (p < 0.05). The intakes of Thiamin of subjects aged 6 ~ 11 months and P of subjects aged over 12 months showed significant differences by level of dietary attitudes (p < 0.05). There was a small positive correlation between education level and nutrition knowledge as well as between dietary attitudes. Nutrition knowledge showed a positive correlation with dietary attitudes. There was a positive correlation between nutrition knowledge and Ca, Riboflavin, as well as Vit C levels. Conclusion: Therefore, it is necessary to consider an educational program for increasing the practical application of knowledge to nutrition management for improvement of nutrition intake in infants and toddlers.

Use of Numerical Simulation for Water Area Observation by Microwave Radar (마이크로웨이브 레이더를 이용한 수역관측에 있어서의 수치 시뮬레이션 이용)

  • Yoshida, Takero;Rheem, Chang-Kyu
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.15 no.3
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    • pp.208-218
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    • 2012
  • Numerical simulation technique has been developed to calculate microwave backscattering from water surface. The simulation plays a role of a substitute for experiments. Validation of the simulation was shown by comparing with experimental results. Water area observations by microwave radar have been simulated to evaluate algorithms and systems. Furthermore, the simulation can be used to understand microwave scattering mechanism on the water surface. The simulation has applied to the various methods for water area observations, and the utilizations of the simulation are introduced in this paper. In the case of fixed radar, we show following examples, 1. Radar image with a pulse Doppler radar, 2. Effect of microwave irradiation width and 3. River observation (Water level observation). In addition, another application (4.Synthetic aperture radar image) is also described. The details of the applications are as follows. 1. Radar image with a pulse Doppler radar: A new system for the sea surface observation is suggested by the simulation. A pulse Doppler radar is assumed to obtain radar images that display amplitude and frequency modulation of backscattered microwaves. The simulation results show that the radar images of the frequency modulation is useful to measure sea surface waves. 2. Effect of microwave irradiation width: It is reported (Rheem[2008]) that microwave irradiation width on the sea surface affects Doppler spectra measured by a CW (Continuous wave) Doppler radar. Therefore the relation between the microwave irradiation width and the Doppler spectra is evaluated numerically. We have shown the suitable condition for wave height estimation by a Doppler radar. 3. River observation (Water level observation): We have also evaluated algorithms to estimate water current and water level of river. The same algorithms to estimate sea surface current and sea surface level are applied to the river observation. The simulation is conducted to confirm the accuracy of the river observation by using a pulse Doppler radar. 4. Synthetic aperture radar (SAR) image: SAR images are helpful to observe the global sea surface. However, imaging mechanisms are complicated and validation of analytical algorithms by SAR images is quite difficult. In order to deal with the problems, SAR images in oceanic scenes are simulated.

Effect of the Nematode Sterilization of Nursery Medium using QRD Microwave in the Plant Factory (QRD 마이크로파를 이용한 식물공장용 배지의 멸균 효과)

  • Kim, Jin Hyun;Kim, Tae Wook;Lee, Keun Woo;Ha, Yu Shin;Lee, Jae Hyun;Kim, Kyung Min
    • Journal of Bio-Environment Control
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    • v.22 no.2
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    • pp.100-107
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    • 2013
  • Unlike general microwave, QRD (Quadratic Residue Diffusor) Microwave used in this study is known as a new technology that enhances the sterilization effect with low power because it is possible to induce the average sterilization by changing wavelength phase difference. Therefore, basic research was conducted on the function that could sterilize culture media for plant factory by using environmentally friendly and low energy consuming QRD Microwave. The results are as follows: It was confirmed that there was no external deformation in the polyurethane foam and rock wool medium when changing the microwave level between 2 and 8 kW in different water content of culture media. However, PDA solid media at 2 kW were not dissolved in 60 and 180 seconds. All of the media were dissolved in other processing. There was little difference in the microwave irradiation level and surface temperature of the strain according to the processing time between Bacillus sp. and Burkholderia sp. In the sterility test according to the microwave irradiation level and processing time, it was confirmed that both Bacillus sp. and Burkholderia sp. grew in the microwave level 2 kW regardless of time. In the microwave level 6 kW, all experimental groups except the processing of Burkholderia sp. for 60 seconds were sterilized, and all of Bacillus sp. was killed in the all experimental groups. In the microwave level 8 kW, it was confirmed that both Bacillus sp. and Burkholderia sp. were sterilized regardless of time. The temperature in microwave-processed media after contaminating strains to each medium was maintained at more than 100 in polyurethane foam and rock wool medium after 60 seconds. In general, it was shown that it was possible to sterilize after 60 seconds. Therefore, it is considered that Bacillus sp. and Burkholderia sp. which are the biggest problems in the plant factory can be adequately sterilized by QRD Microwave used in this study.

Estimation of Total Allowable Pollutant Loads Using Eco-hydrodynamic Modeling for Water Quality Management on the Southern Coast of Korea (생태계 모델에 의한 총허용 오염부하량 산정을 통한 연안해역의 수질관리)

  • Lee, Dae-In;Kim, Jong-Kyu
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.10 no.1
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    • pp.29-43
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    • 2007
  • For effective management of water quality on the southern coast of korea, a three-dimensional eco-hydrodynamic model is used to predict water quality in summer and to estimate the reduction rate in pollutant loads that would be required to restore water quality. Under the current environmental conditions, in particular, pollutant loadings to the study area were very high, chemical oxygen demand (COD) exceeded seawater quality criteria to comply with current legislation, and water quality was in a eutrophic condition. Therefore, we estimated reduction rates of current pollutant loads by modeling. The model reproduced reasonably the flow field and water quality of the study area. If the terrestrial COD, inorganic nitrogen and phosphorus loads were reduced by 90%, the water quality criteria of Region A were still not satisfied. However, when the nutrient loads from polluted sediment and land were each reduced by 70% simultaneously, COD and $Chl-{\alpha}$ were restored. When we reduced the input COD and nutrient loads from the Nakdong River by 80%, $Chl-{\alpha}$ and COD of Region B decreased below $10\;{\mu}g\;1^{-1}$ and $2\;mg\;1^{-1}$, respectively. The water quality criteria of Region C were satisfied when we reduced the terrestrial COD and nutrient loads by 70%. Total allowable loadings of COD and inorganic nutrients in each region were determined by multiplying the reduction rates by current pollutant loads. Estimated high reduction rates, although difficult to achieve at the present time under the prevailing environmental conditions, suggest that water pollution is very severe in this study area, and pollutant loads must be reduced within total allowable loads by continuous and long-term management. To achieve the reduction in pollutant loads, sustainable countermeasures are necessary, including the expansion of sewage and wastewater facilities, polluted sediment control and limited land use.

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서울지역 중년층의 영양섭취실태와 생활습관

  • 이미숙;김성애;백미향;오세인;곽충실
    • Proceedings of the KSCN Conference
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    • 2003.11a
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    • pp.1070-1071
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    • 2003
  • 노년기의 독립적인 생활유지와 삶의 질을 향상시킬 수 있는 바람직한 영양섭취 방법을 모색하기 위한 종적연구의 대상자로 자원한 서울지역의 건강한 40-64세의 중년 293명(남 121명, 여172명)을 대상으로 생활습관과 영양섭취실태를 조사한 결과는 다음과 같다. 대상자의 평균 연령은 남자 52.0$\pm$7.3세, 여자 519$\pm$6.9세였고, 대부분 부부 중심으로 조사하였다. 교육수준은 남자의 71.9%, 여자의 39.5%가 대학졸업 이상이었으며, 남자의 43.0%가 전문직, 24.8%가 행정ㆍ사무직이었고, 가계의 한 달 평균 수입이 200만원 이상자가 72.5%로써 본 조사의 자원자는 대체적으로 고학력, 전문직종의 중류층이었다. 건강에 대한 염려를 가끔 또는 자주 하는 대상자가 66.9%로 건강에 대한 관심은 높았으나 건강을 지키기 위한 실천은 낮은 것으로 나타났다. 그 예로 지난 1년간 체중이 증가하고 있는 대상자가 37.5%였고, 이들 중 75%가 2kg 이상의 체중이 늘고 있지만 체중을 줄이려고 노력하는 대상자는 37.5%뿐이었다. 음주는 남성의 56.5%가 평균 주 2회 정도 하는 편이었고, 1회 음주량은 소주로 1병 이하가 대부분(88%)이었다. 현재 흡연자는 남자의 40.5%였고, 금연자는 30.6%로 비교적 흡연율이 낮았다. 식사시간은 대부분(83.6%) 규칙적이었다. 식사를 주 2-3회 이상 거르는 대상자가 남자는 23%인 반면 여자는 49%였고, 이들 대부분(60.3%)이 아침을 먹지 않았다. 1주일에 1번 이상 외식하는 대상자는 남자의 84%, 여자의 66%였다. 식사시 식품의 배합에 대하여 별로 관심이 없다는 사람이 50%였지만 실제로 식품군별 섭취 시에는 상당한 관심이 있는 것으로 나타났다. 즉, 육류의 기름기를 대충 또는 거의 다 제거하고 먹는 대상자가 남자의 68%, 여자의 88%였고, 육류를 자주 먹지 않거나 소량씩 먹는 대상자가 94%, 생선.두부 및 콩제품을 하루 1끼 이상 섭취하는 대상자가 87%, 채소를 하루 1번 이상 섭취하는 대상자가 96%인 반면, 인스턴트식품이나 패스트푸드를 주 2-3회 이상 먹는 대상자는 23% 정도였다. 영양지식점수(15.4$\pm$3.1/25)와 영양태도점수(50.5$\pm$4.9/75)는 비교적 양호하였다. 전체적으로 오답률이 높은 문항은 체중조절에 있어서 식사와 운동의 관계, 당뇨병 환자의 흰쌀밥 섭취 문제, 비타민제의 섭취와 감기, 고단백 식사의 문제점 등에 관한 것이었다. 반면 철분 섭취와 빈혈의 관계, 비만의 위험성, 동물성 기름의 섭취와 혈중 콜레스테롤치, 우유가 Ca의 급원이면서 성인에게도 필요하다는 것 등은 잘 인식되고 있었다. 조사 대상자의 평균 에너지 섭취량은 RDA의 77.3 $\pm$ 13.6%였으나, 이들 대부분(80%)의 활동 정도가 가벼운 활동에 속하므로 에너지가 부족하다고 할 수는 없다. 반면 평균 단백질 섭취량은 RDA의 109.9 $\pm$ 23.5%로 충분하였고, 3대 열량영양소 즉, 단백질:지방:탄수화물의 구성비는 16:22:62로 지방의 섭취가 약간 높으나 바람직한 구성비를 보였다. 권장량의 75% 이하를 섭취하고 있는 영양소는 칼슘(70.7$\pm$23.9%)뿐이었다. 과체중자의 비율을 체질량지수(BMI) 25이상으로 구분하면 남자의 45%, 여자의 23%가 과체중자로 나타나나, 23이상으로 구분하면 남자의 71%, 여자의 52%가 과체중자로 분류되었다. 이를 WHR의 기준치로 분류하면 남자의 25%, 여자의 26%가 과체중자로 나타났다. 대부분 대상자의 hemoglobin치(99%), hematocrit치(90%), 혈장 albumin치(99.7%)는 양호하였다. 혈당이 140mg/㎗ 이상인 대상자는 2.7%에 불과하였다. 혈중 총콜레스테롤치가 240mg/㎗ 이상인 대상자는 19%, 중성지방치가 250mg/㎗ 이상인 대상자는 9%, HDL-콜레스테롤치가 35mg/㎗ 이하인 대상자는 2.4%로 혈중 지질 profile은 양호하였다. 이상의 결과로 보아 본 연구 대상자는 영양섭취상태와 생화학적 건강상태가 양호하다고 판단되므로 종적연구의 대상자로 적합하다고 사료된다.

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Development of processed food database using Korea National Health and Nutrition Examination Survey data (국민건강영양조사 자료를 이용한 가공식품 데이터베이스 구축)

  • Yoon, Mi Ock;Lee, Hyun Sook;Kim, Kirang;Shim, Jae Eun;Hwang, Ji-Yun
    • Journal of Nutrition and Health
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    • v.50 no.5
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    • pp.504-518
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    • 2017
  • Purpose: The objective of this study was to develop a processed foods database (DB) for estimation of processed food intake in the Korean population using data from the Korea National Health and Nutrition Survey (KNHANES). Methods: Analytical values of processed foods were collected from food composition tables of national institutions (Development Institute, Rural Development Administration), the US Department of Agriculture, and previously reported scientific journals. Missing or unavailable values were substituted, calculated, or imputed. The nutrient data covered 14 nutrients, including energy, protein, carbohydrates, fat, calcium, phosphorus, iron, sodium, potassium, vitamin A, thiamin, riboflavin, niacin, and vitamin C. The processed food DB covered a total of 4,858 food items used in the KNHANES. Each analytical value per food item was selected systematically based on the priority criteria of data sources. Results: Level 0 DB was developed based on a list of 8,785 registered processed foods with recipes of ready-to-eat processed foods, one food composition table published by the national institution, and nutrition facts obtained directly from manufacturers or indirectly via web search. Level 1 DB included information of 14 nutrients, and missing or unavailable values were substituted, calculated, or imputed at level 2. Level 3 DB evaluated the newly constructed nutrient DB for processed foods using the 2013 KNHANES. Mean intakes of total food and processed food were 1,551.4 g (males 1,761.8 g, females 1,340.8 g) and 129.4 g (males 169.9 g, females 88.8 g), respectively. Processed foods contributed to nutrient intakes from 5.0% (fiber) to 12.3% (protein) in the Korean population. Conclusion: The newly developed nutrient DB for processed foods contributes to accurate estimation of nutrient intakes in the Korean population. Consistent and regular update and quality control of the DB is needed to obtain accurate estimation of usual intakes using data from the KNHANES.

Validation of Load Calculation Method for Greenhouse Heating Design and Analysis of the Influence of Infiltration Loss and Ground Heat Exchange (온실 난방부하 산정방법의 검증 및 틈새환기와 지중전열의 영향 분석)

  • Shin, Hyun-Ho;Nam, Sang-Woon
    • Horticultural Science & Technology
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    • v.33 no.5
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    • pp.647-657
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    • 2015
  • To investigate a method for calculation of the heating load for environmental designs of horticultural facilities, measurements of total heating load, infiltration rate, and floor heat flux in a large-scale plastic greenhouse were analyzed comparatively with the calculation results. Effects of ground heat exchange and infiltration loss on the greenhouse heating load were examined. The ranges of the indoor and outdoor temperatures were $13.3{\pm}1.2^{\circ}C$ and $-9.4{\sim}+7.2^{\circ}C$ respectively during the experimental period. It was confirmed that the outdoor temperatures were valid in the range of the design temperatures for the greenhouse heating design in Korea. Average infiltration rate of the experimental greenhouse measured by a gas tracer method was $0.245h^{-1}$. Applying a constant ventilation heat transfer coefficient to the covering area of the greenhouse was found to have a methodological problem in the case of various sizes of greenhouses. Thus, it was considered that the method of using the volume and the infiltration rate of greenhouses was reasonable for the infiltration loss. Floor heat flux measured in the center of the greenhouse tended to increase toward negative slightly according to the differences between indoor and outdoor temperature. By contrast, floor heat flux measured at the side of the greenhouse tended to increase greatly into plus according to the temperature differences. Based on the measured results, a new calculation method for ground heat exchange was developed by adopting the concept of heat loss through the perimeter of greenhouses. The developed method coincided closely with the experimental result. Average transmission heat loss was shown to be directly proportional to the differences between indoor and outdoor temperature, but the average overall heat transfer coefficient tended to decrease. Thus, in calculating the transmission heat loss, the overall heat transfer coefficient must be selected based on design conditions. The overall heat transfer coefficient of the experimental greenhouse averaged $2.73W{\cdot}m^{-2}{\cdot}C^{-1}$, which represents a 60% heat savings rate compared with plastic greenhouses with a single covering. The total heating load included, transmission heat loss of 84.7~95.4%, infiltration loss of 4.4~9.5%, and ground heat exchange of -0.2~+6.3%. The transmission heat loss accounted for larger proportions in groups with low differences between indoor and outdoor temperature, whereas infiltration heat loss played the larger role in groups with high temperature differences. Ground heat exchange could either heighten or lessen the heating load, depending on the difference between indoor and outdoor temperature. Therefore, the selection of a reference temperature difference is important. Since infiltration loss takes on greater importance than ground heat exchange, measures for lessening the infiltration loss are required to conserve energy.

A Study on the Reinforcement Plan for the Local Government to Respond to the Climate Change through the Survey of Residents Consciousness - Focused on the Gangnam-gu - (주민 의식 조사를 통한 지자체 기후변화 대응 강화 방안에 관한 연구 - 강남구를 중심으로 -)

  • Choi, Bong Seok;Park, Kyung Eun;Jeon, Eui Chan
    • Journal of Climate Change Research
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    • v.5 no.1
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    • pp.83-94
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    • 2014
  • Gangnam-gu, where the survey of residents' consciousness has been made in this study, is the district shows the highest rate of the energy consumption and greenhouse gas emission per unit area except some industrial districts such as Gwangyang, Ulsan, and Pohang. The greenhouse gas emission amount of Gangnam-gu is 4,863,765 $tCO_2$ which accounts for 10 % of the total discharging amount of Seoul, 50,330,356 $tCO_2$, which is ranked the top greenhouse gas emission rate in the commercial category and the 2nd place in the household category. The average recognition rate for the 5 subjects of the global warming phenomenons has indicated to be 83.58%. A survey questioning about the main agent to reduce the greenhouse gas, in all age groups except 20s have replied that it should be done by themselves, the residents of Gangnam-gu. For the question of the role of local government to respond to the climate change, the necessity of establishing infrastructure which is suitable for walking and biking. For the other question about the educational facilities to cope with the climate change, many answered the relevant education should be processed from the middle and high schools. For the practical activities in daily life to respond to the climate change, many replies have shown that the energy and resource conservation has been practiced pretty well broadly, but the ecomileage (former carbon mileage) has not been practiced well. Also, many replies have pointed that there were no benefits or rewards for the people who practiced the eco-mileage in their daily lives, which indicates that a kind of incentive is necessary for the efforts to respond to the climate change from the local government to execute the policy substantially and effectively. This study has the purpose to search the political countermeasures to improve the potentiality to reduce the green house gas emission rate through the residents conscious survey about climate change and the political solution by the local government to improve the certain items which showed the lower awareness rate.

A basic study on explosion pressure of hydrogen tank for hydrogen fueled vehicles in road tunnels (도로터널에서 수소 연료차 수소탱크 폭발시 폭발압력에 대한 기초적 연구)

  • Ryu, Ji-Oh;Ahn, Sang-Ho;Lee, Hu-Yeong
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.6
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    • pp.517-534
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    • 2021
  • Hydrogen fuel is emerging as an new energy source to replace fossil fuels in that it can solve environmental pollution problems and reduce energy imbalance and cost. Since hydrogen is eco-friendly but highly explosive, there is a high concern about fire and explosion accidents of hydrogen fueled vehicles. In particular, in semi-enclosed spaces such as tunnels, the risk is predicted to increase. Therefore, this study was conducted on the applicability of the equivalent TNT model and the numerical analysis method to evaluate the hydrogen explosion pressure in the tunnel. In comparison and review of the explosion pressure of 6 equivalent TNT models and Weyandt's experimental results, the Henrych equation was found to be the closest with a deviation of 13.6%. As a result of examining the effect of hydrogen tank capacity (52, 72, 156 L) and tunnel cross-section (40.5, 54, 72, 95 m2) on the explosion pressure using numerical analysis, the explosion pressure wave in the tunnel initially it propagates in a hemispherical shape as in open space. Furthermore, when it passes the certain distance it is transformed a plane wave and propagates at a very gradual decay rate. The Henrych equation agrees well with the numerical analysis results in the section where the explosion pressure is rapidly decreasing, but it is significantly underestimated after the explosion pressure wave is transformed into a plane wave. In case of same hydrogen tank capacity, an explosion pressure decreases as the tunnel cross-sectional area increases, and in case of the same cross-sectional area, the explosion pressure increases by about 2.5 times if the hydrogen tank capacity increases from 52 L to 156 L. As a result of the evaluation of the limiting distance affecting the human body, when a 52 L hydrogen tank explodes, the limiting distance to death was estimated to be about 3 m, and the limiting distance to serious injury was estimated to be 28.5~35.8 m.