• Title/Summary/Keyword: Gas absorption

Search Result 885, Processing Time 0.023 seconds

Fault Analysis of Transformer using Tunable Infrared Gas Sensors (가변 파장형 적외선 센서를 이용한 변압기 결함 진단)

  • Gun-Ho Lee;Seung-Hwan Yi
    • Journal of Sensor Science and Technology
    • /
    • v.32 no.1
    • /
    • pp.55-61
    • /
    • 2023
  • The objective of this study is to determine the concentrations of mixed gases by establishing a diagnosis method of a transformer using tunable-wavelength optical infrared sensors. Absorption of infrared light by methane, acetylene, and ethylene gases injected is measured from the outputs of the infrared sensors. Regression analysis equations of the gas concentrations are acquired from their respective measured absorption. The obtained concentrations are as follows: -3-9 % errors above 600 ppm(methane), 3 % errors above 1200 ppm(acetylene), and 10 % errors above 500 ppm(ethylene). The concentration inference equations obtained using the individual gases are applicable when the absorption wavelength bands do not overlap. The results of the fault analysis of a transformer using the Duval triangle method and the tunable infrared gas sensors are as follows: temperature faults with -1-1% errors and energy faults with -7-7 % errors.

Real-time Analysis of Exhaust Gas Temperature Field in Turbulent Flow Using Laser Absorption Spectroscopy (레이저흡수분광을 이용한 난류유동 배기가스 온도장 실시간 분석 연구)

  • Doo Won Choi
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.37 no.2
    • /
    • pp.73-78
    • /
    • 2024
  • This study presents a real-time method that uses Laser Absorption Spectroscopy (LAS) to measure exhaust gas temperatures in turbulent flow fields. It was possible to measure temperature by passing a laser beam through the exhaust gas in a grid pattern, and obtain a temperature distribution image through time series analysis at 0.1 second intervals. Temperature image resolution has been improved with CT reconstruction algorithms. Estimating maximum temperature values and locations enabled 2D temperature analysis, surpassing single-point methods like thermocouples. The accuracy of LAS measurements was evaluated by comparison with thermocouple measurements. This approach will contribute to automotive technology and environmental protection by providing reliable temperature data for interpreting turbulent temperature distributions.

The Effect of Gas Absorption Induced a Change of Glass Transition Temperature in Microcellular Foamed Plastics (초미세 발포 플라스틱의 유리전이온도를 변화시키는 가스 용해량의 영향)

  • Hwang, Yun-Dong;Cha, Seong-Un
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.25 no.5
    • /
    • pp.816-822
    • /
    • 2001
  • The thermoforming process is widely used in the plastics industry to produce articles for the packaging, automotive, domestic construction and leisure industries. The microcellular foaming process appeared at M.I.T. in 1980s to save a quantity of polymer materials and increase their mechanical properties. The glass transition temperature of polymer materials is one of many important process variables in appling the microcellular foaming process to the conventional thermoforming process. The goal of this research is to evaluate the relation between gas absorption and glass transition temperature in batch process using microcellular foaming process. The weight gain ratio of polymer materials has a conception of gas absorption. Polymers such as acrylonitrile-butadiene-styrene(ABS), polystyrene(PS) have been used in this experiment. According to conventional Chows model and Cha-Yoon model, it was estimated with real experimental result to predict a change of glass transition temperature as a function of the weight gain ratio of polymer materials in batch process to gain microcellular foamed plastic products.

The Study on Corrosion Characteristics of Heat Exchanger Tube for Gas Absorption Refrigeration & Hot Water System (가스흡수식 냉온수기 열교환기용 세관의 부식특성에 관한 연구)

  • Jeong Ki Cheol
    • Journal of the Korean Institute of Gas
    • /
    • v.6 no.1 s.17
    • /
    • pp.92-97
    • /
    • 2002
  • This paper was studied on corrosion characteristics of gas absorption refrigeration & hot water system using $LiBr-H_2O$ working fluids. In the $62\%$ lithium bromide solution at $60^{\circ}C$, polarization test of Cu, $10\%$ cupronickel($90-10\%$ Cu-Ni) and $30\%$ cupronickel($70-30\%$ Cu-Ni) tube was carried out. And polarization behavior, polarization resistance characteristics, open circuit potential, anodic polarization of heat exchanger tube for gas absorption refrigeration & hot water system were considered. The main results are as following: 1) Polarization resistance of heat exchange tubes appears high in order of $30\%$ cupronickel tube > $10\%$ cupronickel tube > Cu tube. B) Open circuit potential of cupronickel tube is more noble than that of Cu tube, and corrosion current density of cupronickel is controlled than Cu tube. 3) Potential of passive region of $30\%$ cupronickel tube is more wide than that of $10\%$ cupronickel tube, and the passivation critical current of $30\%$ cupronickel tube is lower than that of $10\%$ cupronickel tube.

  • PDF

Characteristic analysis of air-cooled absorption refrigeration machine (공냉식 흡수식 냉동기의 특성 해석)

  • Kwon Oh-Kyung;Moon Choon-Geun;Yang Young-Myung;Yu Sun-Il;Yoon Jung-In
    • 한국가스학회:학술대회논문집
    • /
    • 1998.09a
    • /
    • pp.249-254
    • /
    • 1998
  • This paper describes the study of developing air-cooled absorption system which uses a new working solution instead of LiBr solution to improve the performance of system. The absorption chiller-heater considered was an air-cooled, double-effect, $H_2O/LiBr+HO(CH_2)_3$ system of parallel flow type. In this study, we found out the characteristic of new working solution through the cycle simulation and compared the result that of LiBr solution to evaluate. The new working fluid has a wider working range with $8\%$ higher crystallization limit at the saturated refrigerant pressure of 0.8kPa. The optimum designs and operating conditions of air-cooled absorption system were suggested based on this cycle simulation analysis. It was demonstrated that new working fluid substantially improves the performance of the absorption refrigeration machine and is expected to increase the COP by as much as $5\%$.

  • PDF

The Simultaneous absorption of SOX-NOX using aqueous ammonia solution (암모니아수용액을 이용한 SOX-NOX 동시 흡수에 관한 연구)

  • Kim, Jae-Gang;Lee, Ju-Yeol;Park, Byung-Hyun;Choi, Jin-Sik
    • Journal of the Korean Applied Science and Technology
    • /
    • v.32 no.3
    • /
    • pp.372-376
    • /
    • 2015
  • The experiment was performed using the cleaning precipitator To investigate the absorption efficiency of the $SO_X/NO_X$ of the aqueous ammonia solution. Concentration of the cleaning liquid is 0.1, 0.5, and 1.0% with increasing absorption efficiency has improved. However, the reaction shown only a difference in time. Absorption efficiency has improved in accordance with the gas residence time. When the direction of the same gas and the cleaning liquid is determined that there is the effect of increasing the residence time. The relative impact of $SO_X$ and $NO_X$ is this likely to react slower than $SO_X/NO_X$. The yield is determined to require adjustment of the cleaning dust collector according to the concentration of the next gas.

Numerical prediction of hydrogen storaging performance of finned metal hybride beds (휜이 달린 수소저항합금 베드의 수소저장 성능의 수치적 예측)

  • Kim, Myeong-Chan;Lee, Sang-Yong;Gu, Jae-Hak
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.22 no.4
    • /
    • pp.520-529
    • /
    • 1998
  • Heat and mass transfer behaviors of metal hydride beds were predicted by solving a set of volume-averaged equations numerically both for the gas (hydrogen) and the solid(metal hydride) phases. Time variations of temperature and hydrogen concentration ratio distributions were obtained for internally cooled, cylindrical-shaped beds with metal(aluminum) fins imbedded in them. Also, time variations of the space-averaged hydrogen concentration ratio were obtained. Temperature and velocity of the coolant, hydrogen pressure at the gas inlet, and the fin spacing were taken as the parameters. The hydrogen absorption rate increases with the higher velocity and the lower temperature of the coolant, and with the decrease of the fin spacing. Increasing of the hydrogen pressure at the gas inlet also promotes the rate of absorption though the increasing rate gradually slows down. The amount of the hydrogen storage per unit volume of the bed decreases with the tighter fin spacing despite of the higher absorption rate ; therefore, there should be an optimum fin spacing for a given volume of the system and the amount of the hydrogen storage, in which the absorption rate is the highest.

A Study on the Separation of $CO_2$from Flue Gas by Chemical Absorption (화학흡수법에 의한 연소폐가스 중 지구온난화 가스 $CO_2$분리에 관한 연구)

  • 안성우;김영국;송호철;박진원
    • Journal of Energy Engineering
    • /
    • v.6 no.2
    • /
    • pp.203-211
    • /
    • 1997
  • This study is on the separation of Global warming effect gas, CO$_2$by chemical absorption from mixture of CO$_2$-N$_2$which was modeled after flue gas of fire power plant. Investigation of optimum condition for absorbent was carried out by using sparged vessel apparatus. Through packed tower experiments, applicabilities of two absorption models were tested by comparing experimental results with theoretical values. Absorbent used in the experiments was Monoethanolamine (MEA) and gas mixture was made in the mole composition of 15% CO$_2$and 85% N$_2$. Through estimations of CO$_2$loading and CO$_2$removal efficiency, optimum concentration of absorbent was found in the range of 4-5 M. To find a rate of absorption, an enhancement factor was introduced. Values of rate of absorption were calculated by Film model and Higbie model, respectively. Higbie model showed good agreement with experimental results. Therefore, this models is considered to be applicable to the CO$_2$separation process for flue gas from fire power plant.

  • PDF

Study on Improving Environmental Impact Assessment of Carbon Sink in the Greenhouse Gas Evaluation Criteria for Railway Construction Projects for Carbon Neutrality (탄소 중립을 위한 철도 건설 사업 온실가스 평가항목의 탄소흡수원 분야 환경영향평가 개선 방안 연구)

  • Hwang, Jin-hoo;Namuun, Tuvshinjargal;Won, Joo-hee;Kim, Min-jeong;Park, Da-hye;Jeon, Seong-woo
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.26 no.3
    • /
    • pp.43-55
    • /
    • 2023
  • The railway project is an essential green transportation tool that is considered suitable for the domestic and foreign policy direction of carbon neutrality, but there are some limitations, such as damaging important carbon absorption sources during construction. This study analyzed the environmental impact assessment related to carbon absorption sources of greenhouse gas evaluation items conducted during the railway project, and limitations and implications were derived. The analysis of environmental impact assessment guidelines related to railway projects and carbon absorption sources dealt with prediction and reduction methods related to carbon absorption sources, but guidelines, including environmentally friendly railway construction guidelines, lacked descriptions. Since the greenhouse gas environmental impact assessment, 83 railway project environmental impact assessments have been reviewed, but in some cases, carbon absorption-related predictions have not been implemented, or carbon absorption-related reduction measures have been insufficient. In addition, there were cases where there was a limit to calculating emissions and reduction or where the reduction value was insignificant compared to emissions. In order to supplement the environmental impact assessment in the field of carbon absorption sources related to railway construction projects, alternatives such as quantitative emission and low reduction calculation, review of the no net loss system using the total environmental resource system, and linkage with climate change impact assessment are needed.

HCO+ Observations toward Compact Radio Continuum Sources Using the KVN 21-m Telescopes to Trace Dark Molecular Gas

  • Park, Geumsook;Koo, Bon-Chul;Kim, Kee-Tae;Byun, Do-Young;Heiles, Carl
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.2
    • /
    • pp.52.3-53
    • /
    • 2015
  • It has been known that there is "dark gas" invisible either in 21-cm HI or 2.6-mm CO emission which are general tracers of atomic and molecular gas, respectively. Many researchers consider that the dark gas is "Dark Molecular Gas (DMG)" composed of CO-free $H_2$ in the intermediate zone between atomic and full-fledged molecular gas and that HCO+ and OH molecules are good tracers of the DMG since they can form in much lower $H_2$ column densities where CO does not. We have carried out HCO+ J=1-0 absorption observations toward nine bright extragalactic radio continuum sources using the KVN 21-m telescopes as single dishes. We detected HCO+ absorption lines toward two sources. We derive HCO+ and $H_2$ column densities or their limits, and discuss the implications of our results.

  • PDF