• Journal of the Korean Institute of Gas
• /
• v.12 no.2
• /
• pp.1-6
• /
• 2008

For the safety design and operation of many gas process, it is necessary to know certain explosion limit, flash point, autoignition temperature (AIT) and minimum oxygen concentration of handling substances. Also it is necessary to know explosion limit at high temperature and pressure. In this study for the safe handling of hydrogen, explosion limit and AIT of combustion properties for hydrogen were investigated. By using the literatures data, the lower and upper explosion limits of hydrogen recommended 4.0 vol% and 77.0 vol%. Also the AIT of hydrogen with ignition sources recommended $400^{\circ}C$ at the electrically heated crucible furnace (the whole surface heating) and recommended $640^{\circ}C$ at the local hot surface. The new equations for predicting the temperature and the pressure dependence of the explosion limits of hydrogen are proposed. The values calculated by the proposed equations were a good agreement with the literature data.

• Journal of the Korean Institute of Gas
• /
• v.24 no.4
• /
• pp.32-38
• /
• 2020

Based on the cases of fire and explosion accident in the chemical reactor, thr problems of preventive measures installed in the chemical reactor were analyzed. The chemical reactors produce a variety of chemicals and install rupture disk to relieve the pressure that rises sharply in the event of a runaway reaction. In order to maintain the function of the rupture disk, the emissions was allowed to be discharged into the atmosphere, resulting in fire and explosion accidents. As a way to improve this, safety instrumented system based on the safety integrity level(SIL3) was applied as a preventive measures for chemical reactor. Two emergency shur-off valves are installed in series on pipe dropping raw materials for chemical reactor so that the supply of raw materials can be cut off even if only one of the two emergency shut-off valves is operated during the runaway reaction. The automatic on/off valve is installed in parallel in the supply pipe of the reaction inhibitor so that the reaction inhibitor can be injected even if only one valve is opened at the time of the runaway reaction.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.6
• /
• pp.1207-1213
• /
• 2007

This paper has researched water supply facilities management using real-time water utility monitoring system based on USN(Ubiquitous Sensor Network) which is consisted of wireless sensors transferring waterworks facilities md treatment information about a valve-room and flowmeter-room of water supply installation. In the manholes, it was installed with flowmeter, pressure sensors, vibration sensors, Co-sensors, and hydro-thermograph sensors. These measurement values which are received by PDA are used for facilities operation on the spot safely and conveniently. It has also provided safe installation management via CDMA(Code Division Multiple Access) network which transfers data to remote servers to monitoring at a distance place. With safety management system of water supply facilities on USN technology convenience and safety is increased in real situation, and it is expected that we can supply clean water to people as much safer and more effective water supply installation management.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.457-460
• /
• 2009

u-IT Convergence appliances study and are developed in communication by development of u-IT technology, broadcasting, portal, contents, equipment and all fields of business such as solution. This treatise presents valuation basis of, economic performance, administration sex etc. by temperature, pressure, own, storehouse, gas, justice for humidity sensors and valuation basis that define u-IT Convergence, and sense information u-IT Convergence devices and terminal. Also, studied standardization standard of u-IT Convergence network appliance that follow in valuation basis for u-IT Convergence devices. Is going to contribute establish value as estimation product that equip stability and authoritativeness through correct certification assessment for technological development and appliances on Ubiquitous information-oriented society through this research and accomplish standardization.

• Journal of the Korean Institute of Gas
• /
• v.25 no.1
• /
• pp.40-47
• /
• 2021

In this study, hazards of decomposition and explosion for tert-butylperoxymaleate(TBPM), an organic peroxide, were evaluated by using various equipment to determine the cause of a fire explosion accident. As a result of DSC analysis, the instantaneous power density of TBPM was 26,401 kW/ml, and the NFPA reactive index(Nr) was classified as 4. And the positive value of EP(explosive propagation) and SS(shock sensitivity) showed that the TBPM had a potential hazard of explosion. From the experimental results, the shock sensitivity and friction sensitivity was rated as class 4 and 5, respectively. In the pressure vessel test, TBPM was ranked USA-PVT No.4 and evaluated as a self-reactive substance. In the combustion rate test, TBPM had the combustion rate of 167 mm/sec and was evaluated as the flammable solid classification 2 in GHS.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.2
• /
• pp.355-362
• /
• 2021

To facilitate low-pressure selective catalyst reduction (L.P SCR), a high exhaust-gas temperature of a four-stroke diesel engine for a ship's generator is required. This study aimed at reducing the exhaust-gas temperature by adjusting the valve open-close timing and fuel injection timing to satisfy the operating conditions of L.P SCR and prevent accidents associated with the generator engine due to high temperature. To lower exhaust-gas temperature, the angle of the camshaft was adjusted and the shim of the fuel injection pump was added. As a result, the maximum explosion pressure increased and the average of the turbocharger outlet temperature dropped. Considering the heat loss from the turbocharger outlet to the SCR inlet, the operation condition for L.P SCR was satisfied with 290 ℃. The study demonstrates that safe operation of a diesel generator can be achieved by lowering the exhaust-gas temperature.

• Journal of the Korean Institute of Gas
• /
• v.26 no.4
• /
• pp.36-40
• /
• 2022

Recently, the biggest topic in the industry is the area of industrial safety and health management. Since city gas is flammable gas and has a high risk of fire and explosion, much effort is required to prevent serious industrial and citizenry disasters. As part of city gas safety management, this study attempted to quantitatively predict the scope and degree of damage in the event of an explosion accident caused by city gas leakage through the Consequence Analysis. As a result, there was a difference in the accident result value according to various leakage conditions such as pressure and weather conditions. Through this study, a scenario of explosion due to city gas leakage will be prepared when performing city gas safety management work and used to prepare more effective accident prevention and emergency action plans.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.1
• /
• pp.545-550
• /
• 2023

A pretensioner is a safety device that protects occupants by pulling the seat belt in the event of a vehicle collision. However, since the pretensioner is driven by a explosive method, it is necessary to replace not only the gas generator but also all connecting parts including the manifold after an accident. Therefore, in this paper, we propose an elastic force-based pretensioner that can be used safely and semi-permanently. After analyzing the operating mechanism of the existing pretensioner from a thermodynamic/dynamic point of view, the spring stiffness that can be deployed within an appropriate operating time was determined by converting the gas explosion energy into elastic energy. In addition, the coil spring shape that satisfies the elastic stiffness was designed in consideration of the vehicle interior installation standard. Finally, the operating performance of the pretensioner driven by elastic force was verified through fabrication.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.5
• /
• pp.44-51
• /
• 2022

In this study, 5-axis machining was proposed as a method for manufacturing a nozzle with a curved shape, and flow analysis and structural analysis were used for structural validation of the manufactured geometry. The program used for CFD obtained the internal temperature and pressure distribution of the nozzle using STAR-CCM+ and used it as the boundary condition for structural analysis. For structural analysis, the commercial program NASTRAN was used, and stress was calculated using the von-mises technique. Based on the maximum stress value generated, the safety margin was 0.78 and the safety margin of the bearing stress was 46.8. In addition, the creep life was calculated as 9.97 x 1012 hours using the Larson-Miller parametric method and applying the maximum stress value of 187 MPa and the exhaust gas perfectly mixed temperature of 463 K.

• The Journal of the Acoustical Society of Korea
• /
• v.26 no.5
• /
• pp.220-226
• /
• 2007

The two major objectives of acoustical measurements in a cavitation tunnel are measuring the noise levels generated by rotating propellers behind a hull and localizing possible noise sources in order to reduce noise levels. Propeller noise measurement experiments were performed in MOERI cavitation tunnel at December, 2006. In order to put the propeller into cavitating conditions, a wake-generating dummy body was devised. In addition, ten hydrophones are put inside a wing-shaped casing in order to minimize the unexpected flow induced self noise around hydrophone itself. After measuring both of the noises of the rotating propeller behind the dummy body and signals generated by a virtual source, respectively the data were matched field processed using the frequency incoherent Bartlett processor to localize noises on the propeller plane. In this paper, we presented the measured noise analysis and the localization results.