• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.87-101
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• 2012

In gas industries, the potential risks of serious accidents have been increased due to high technology application and process complexities. Especially, in case of gas-related accidents, the extent of demage is out of control since gas plants handle and produce combustible, flammable, explosive and toxic materials in large amounts. The characteristics of this kind of disaster is that accident frequency is low, while the impact of damage is high, extending to the neighboring residents, environment and related industries as well as employees involved. The hydrogen gases treated important things and it used the basic material of chemical plants and industries. Since 2000, this gas stood in the spotlight the substitution energy for reduction of the global warming in particular however it need to compress high pressure(more than 150 bar.g) and store by using the special cylinders due to their low molecular weight. And this gas led to many times the fire and explosion due to leak of it. To reduce these kinds of risks and accidents, it is necessary to improve the new safety management system through a risk management after technically evaluating potential hazards in this process. This study is to carry out the quantitative risk assesment for hydrogen filling plant which are very dangerous(fire and explosive) and using a basic materials of general industries. As a results of this risk assessment, identified the elements important for safety(EIS) and suggested the practical management tools and verified the reliability of this risk assessment model through case study of accident.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.75-78
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• 2006

With the increasing environmental consideration and stricter regulations waste gasification is considered to be more attractive technology than conventional incineration for energy recovery as well as material recycling. The experiment for combustible waste was performed In the fixed bed gasifier to investigate the gasification behavior with the operating conditions in a 5ton/day fixed bed gasifier The experiments of operation with 10-50 hours were carried out to determine the effects of bed temperature and oxygen/waste rat io on the syngas composition, calorific value and carbon conversion. The calorific values of the produced syngas decreased with an Increase of bed temperature because combust ion reaet ion more act ively happened. The syngas composition of wood waste gasification is CO: 34.4%, $H_2: 10.7%,\;CH_4: 6.0%,\;CO_2: 48.9%$ and that of RPF is CO: 33.9%, $H_2: 26.1%,\;CH_4: 10.7%,\;CO_2: 29.2%$. The average calorific values of produced gas were about $1,933kcal/Nm^3,\;2,863kcal/Nm^3$, respectively

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.3
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• pp.63-71
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• 2006

A downdraft gasifier was made of stainless steel for biomass gasification. Internal reactor had a 300 mm diameter and 8 air intakes. Three thermocouples were installed to measure the temperature inside the reactor. Three different biomass fuels were provided in the experiments to find out the effects of fuel conditions on gasification processes; charcoals, woodchips, and mixture of woodchip and charcoals. Two different experiments were conducted fer charcoal experiments, small and larger sizes of charcoal fuels. It took about 10 minutes after ignition to generate combustible producer gas when charcoal was f9d, but 20 or more minutes for woodchips. When the gasification was stabilized, the highest temperature was observed just below the combustion zone. The air flow rate for woodchip experiment was provided at 25% of a stoichiometric requirement of combustion, which was within the range of typical air flow rate fer woody biomass gasification. Carbon monoxide concentrations were also within the values reported in the previous studies, ranging 20 to 30% depending on fuel types. It could be seen that fuel size and heating value were very important parameters in biomass gasification. These parameters should be taken into account in operating and designing biomass gasifiers.

• Nuclear Engineering and Technology
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• v.21 no.4
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• pp.321-331
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• 1989

A bench scale incineration process for the burnable radwaste has been constructed and operated at KAERI as a self-surpported development of incineration technology. The purposes of operating the process are to get experience in incineration, to analyze the characteristics of combustion and to test the performance of off-gas treatment units. Simulated paper and polyethylene wastes were incinerated. Volume reduction ratio and decontamination factor of the process have been determined to observe the economical efficiency and operational capability of the process. A methodology to estimate the acceptance limit of specific activity to an incineration facility by using a decontamination factor and to calculate the volume reduction ratio of the facility is introduced. The acceptance criteria for different radionuclides in the combustible waste at the bench scale incineration process are suggested using this methodology.

• Journal of the Korean housing association
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• v.23 no.5
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• pp.41-49
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• 2012

As improving our standard of living, demographic change or industrial development, MSW that is closely linked to human behavior has been occurred much change. Notably, we usually have incinerated the combustible waste. In the process, they also emit a large amount of greenhouse gas that has directly affected the global warming and environmental pollution. Therefore, we need to make control system to manage future production and reduce generation of MSW. Thus this study analyzed the generation of MSW according to household members and floor area in apartment housing occupies the highest share. Then, we used both a correlation analysis and a regression analysis to make new estimation model of MSW generation. Based on this study, the results were used to suggest a method to efficiently handle MSW in the case of planning urban environment. Also, build a database to set up the integrated management system of MSW in the future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.75-83
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• 2005

A steady transonic dilute premixed combustion in a diverging channel is investigated by using asymptotic analysis. This model explores the nonlinear interactions between the near-sonic speed of the flow, the small changes in geometry from a straight channel, and the small heat release due to the one-step first-order Arrhenius chemical reaction. The reactive flow is described by a nonhomogeneous transonic small-disturbance (TSD) equation coupled with an ordinary differential equation for the calculation of the reactant mass fraction in the combustible gas. Also the asymptotic analysis reveals the similarity parameters that govern the reacting flow problem. The results show the complicated nonlinear interaction between the convection, reaction, and geometry effects and its effect on the flow behavior.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.32-39
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• 2004

HCCI (Homogeneous Charge Compression Ignition) combustion has a great advantage in reducing NOx (Nitrogen Oxides) and PM (Particulate Matter) by lowering the combustion temperature due to spontaneous ignitions at multiple sites in a very lean combustible mixture. However, it is difficult to make a diesel-fuelled HCCI possible because of a poor vaporability of the fuel. To resolve this problem, the two-stage injection strategy was introduced to promote the ignition of the extremely early injected fuel. The compression ratio and air-fuel ratio were found to affect not only the ignition, but also control the combustion phase without a need for the intake-heating or EGR (Exhaust Gas Recirculation). The ignition timing could be controlled even at a higher compression ratio with increased IMEP (Indicated Mean Effective Pressure). The NOx (Nitrogen Oxides) emission level could be reduced by more than 90 % compared with that in a conventional DI (Direct Injection) diesel combustion mode, but the increase of PM and HC (Hydrocarbon) emissions due to over-penetration of spray still needs to be resolved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05b
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• pp.8-11
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• 2003

We propose that when combustible burn with contain carbon, introduce fire detector with sensor of private-use detectable light energy as infrared and ultraviolet in energy of electromagnetic-wave type radiate from flame, method for correct discrimination to resemble fire produce false alarm of detector such as sun light, hot object radiation, are welding. This research using infrared sensor is pyroelectric infrared sensor based black body radiation theory. Ultraviolet sensor is uv Tron using gas multiplication effect to current discharge and photoelectric effect of metal. To have high sensibility and to gain proper output voltage, it has high responsive performance. This research introduced UV/IR compound type flame detector and proposed method of false alarm reduced to resemble fire. The result propres the prevention and extinction of fire technique degree, certificated operation of detector.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.1
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• pp.21-30
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• 1999

The research for retecting of insulating deterioration in transforrrer has been studied from long ago and the analysis rrethod of combustible gas which is included in insulating oil has been used Recently the spreading effect of the accident is larger than before because of high voltage and large capacity, so on-line detecting system is needed and the study for the estimation of partial discharge signals location has begun. This thesis is the study for the sermating noise signal that is the greatest problem in ultrasonic signal measurement which is one of the method of estimation of partial discharge signals location. Because we can measure the number and location of signal, it is rossible to distinguish between the signal of partial discharge and the external noise. Therefore, we can devolop the credibility of detecting of insulating deterioration in transformer.former.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.5
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• pp.1104-1112
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• 1988

In this study the structure of a two phase detonation has been numerically investigated through the assumption of a steady and one-dimensional flow in the suspension of carbon particles and pure oxygen. The bow shock formation in front of carbon particles has been taken into consideration when the relative velocity of gas flow with respect to the particle exceeds the local speed of sound. But its effect was found to be very limited to the induction zone only. Furthermore the interior particle temperature distribution has been considered in this work. It was found that the inner temperature gradient was very steep in the region of high relative velocity. On the while the temperature distribution inside the particle was almost uniform in the region of low relative velocity. Overall, the effect of the interior particle temperature distribution has been significant in the two phase detonation.