• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.3
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• pp.216-223
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• 2008

Reburning is a useful technology in reducing nitric oxide through injection of a secondary hydrocarbon fuel. In this paper, an experimental study has been conducted to evaluate the effect of fuel lean reburning on $NO_X/CO$ reduction in LPG flame. Experiments were performed in flames stabilized by a co-flow swirl burner, which was mounted at the bottom of the furnace. Tests were conducted using LPG gas as the reburn fuel as well as the main fuel. The effects of reburn fuel fraction and injection location of the reburn fuel were studied when the fuel lean reburning system was applied. The paper reports data on flue gas emissions and temperature distribution in the furnace for a wide range of experimental conditions. At steady state, temperature distribution and emission formation in the furnace have been measured and compared. This paper makes clear that in order to decrease both NOx and CO concentrations in the exhaust when the fuel lean reburning system was adapted, it is important that the control of some factors such as initial equivalence ratio, reburn fuel fraction and temperature of reburn fuel injection region. Also it shows the fuel lean reburning is also effective method to reduce NOx as much as reburning.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1669-1678
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• 1990

The annular and coaxial swirl flows between which LPG is supplied was selected to study the swirling flames in double co-swirl flows. The objective of this study is to research into the effects of double co-swirl flow conditions on the stability limit, the reverse flow boundary, and the time mean temperature distributions of the swirling flames. The increase of swirl intensity of axial flow makes the stability limit decrease, but the annular swirl flow (SM>0.5) makes stability and swirl intensity of axial flow increase, And the existence of axial swirl flow makes flame intensive and small in size, and this may be applicable to the design of high power compact combustor.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.273-281
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• 2006

Singeing has always been equated with meat color alteration through lipid oxidation and microbial population. Singeing method has always been employed far removing duck feathers, however, the effect of singeing on storage characteristic of duck meat has not been investigated extensively. The study was therefore, designed to Investigate the effect of singeing on duck meat during storage extensively. For the purpose, study was categorized into three groups namely A, B, and C, representing 0, 50 and 70 seconds of singeing time. Singeing was performed on 100 birds in each group, however, only 20 singed birds from each treatment groups were further selected to analyse them subsequently during storage. Analysis revealed that with 70 seconds singeing time drip loss was significantly (p<0.05) higher at $6mgf/cm^2$ compared to 50 seconds of singeing. With 70 seconds treatment breast meat apparently appeared black, where as with 50 seconds treatment no change was observed. Breast showed low redness with more duration of treatment compared to less treatment duration. Yellowness increased, springiness declined and no change was observed in cohesiveness and chewiness with high treatment time. There was increase in the TBARS and VBN, freshness did not change for first 5 days, however, K values started to increase later on indicated decline in freshness. Conclusively, it was inferred from the study that 50 seconds singeing does not make much alternation in the quantitative traits and at the same time maintains the microbial level under permissible limit.

• Journal of the Korean Society of Combustion
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• v.1 no.1
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• pp.11-18
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• 1996

The stabilization characteristics of diffusion flame formed behind a bluff body with fuel injection slits was experimentally investigated by varying main fuel injection angles and auxiliary fuel injection conditions. The flame stability limits, temperature and length of recirculation zone, direct and schlieren photographs of flames were measured in order to study the stabilization mechanism of the diffusion flame. The results of this investigation are as follows. The stability limits can be improved by the condition of the kind and quanity of the injected auxiliary fuel. The length and temperature decrease with injection of auxiliary fuel, and these phenomena are remarkable when LPG is injected into the recirculation zone. When the LPG is injected into the recirculation zone, flame remains sooty. Fluctuation of fuel and main stream is generated actively by air injection.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.4
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• pp.518-524
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• 1997

Experimental studies on combustion phenomena within a porous ceramic burner are reported. Main interest of the present work is to investigate fundamental flame behaviors and their effects on the burner operation. Due to high thermal capacity of the porous ceramic materials, the response of flame to burning condition changes is slow and thus to have a stabilized flame is quite difficult and takes much time. It is found that the temperature profile obtained at downstream of the flame zone is not much sensitive to the movement of flame and the speed of flame movement is less than 0.1 mm/sec for the conditions tested. With the premixed LPG/air flame imbedded within the porous ceramic burner, stable combustion regions and unstable combustion regions leading to blowoff or flashback phenomena are observed and mapped on flow velocity versus equivalence ratio diagram. For the development of burner operation technique which is more practical and safe, intermittent burning technique, where the fuel or/and air is supplied to the burner intermittently, is proposed as one of the flame control methods for the porous ceramic burner and tested in this study. Through the experiment, it is realized that the proposed method is acceptable in respect to burner performance and give much flexibility in the operation of porous ceramic burner.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.2
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• pp.328-335
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• 2002

In this study, experiments were performed to investigate the characteristics of flame stabilization of the LFG mixing gas. LFG has merely half heating value compared with liquified natural gas but can be greatly utilized as a commercial fuel. In order to use LFG in practical combustors, Webbe Index and heating value of LFG mixing gas were adjusted by mixing LPG with LFG. The comparisons were conducted between CH$_4$and LFG mixing gas for searching the region of flame stabilization based upon the flame blowout at maximum fuel stream velocity. As a result, the flame stability of LFG mixing gas was not improved with that of CH$_4$in non-swirl and weak swirl diffusion flame. However, LFG mixing gas had wide flame stabilization region rather than CH$_4$with increasing ambient flow rate in strong swirl. It was also found that flame stability was affected by included quantity of inert gas such as CO$_2$in the weak swirl but by heating value of fuel in strong swirl.

• Journal of the Korean Institute of Gas
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• v.15 no.5
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• pp.7-12
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• 2011

LPG(Liquefied Petroluem Gas) Vehicles in metropolitan area being applied to improve air quality and have been proven effective for the reduction of air pollution. These gas stations are required to safe the storage tank because of possibility of causing huge loss of life and property. While storage tanks above ground have potential risk of explosion if fire breaks out and those under-ground are difficult to inspect due to poor accessibility neither above nor under-ground tank can serve us well. This study used the RPS-TRIZ (Rapidly Problem Solving-Teoriya Resheniya Izobretatelskikh Zadatch) technique and suggested the use of under-ground containment storage tank as a solution for safety issues and safety inspection.

• Journal of the Korean Institute of Gas
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• v.16 no.4
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• pp.59-64
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• 2012

The dispersion of gas discharged from the vent pipes of pressure relief valves attached LPG (Liquefied Petroleum Gas) storage tank was studied. In general, vent pipes should be positioned so that they discharge vertically upwards in a safe place, and installed so that, in the event of ignition of discharged gas, flame impingement on any vessel, equipment or piping is avoided[1][2]. In Korea, on the other hand, there are various type of the end of vent pipes because there is no rule for discharge directions from the vent pipes. In this paper, we took 4 types of vent directions from the pipes in to account, such as vertically upward, vertically downward, vertically 4-way and horizontally 2-way direction. A software package, FLACS, was adopted to simulate gas dispersion from the vent pipes. We found that vertically downward, vertically 4-way and horizontally 2-way discharge from vent pipes were undesirable to avoid ignition on near ground. Therefore, it was obvious that vertically upward opening of a vent pipe is the best option to discharge in a safe place.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.7-13
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• 2017

As environmental problems become a problem of survival, interest in eco-friendly energy is increasing to improve the environment. So, demand for eco-friendly fuels such as hydrogen, LPG and CNG is increasing. In particular, Korea, which relies on imports of most fuels, is investing in the development of hydrogen energy, which is favorable in terms of high production volume and energy independence. However, As demand grows every year, a variety of accidents occur in various ways, ranging from small leak incidents to massive fires and explosion, thus research needs to be done. So, in this study, compared and analyzed cases of hydrogen, LPG, CNG accidents occurring at domestic and overseas refueling stations. and various programs were used for assessing risk, estimated the flame length due to gas leakage and evaluated the dangerous distance.

• Journal of the Korean Institute of Gas
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• v.19 no.4
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• pp.22-28
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• 2015

In order to keep the competitiveness of LPG fuel for transportation fuel, the difference in fuel consumption with gasoline and cost for an aftertreatment system should be reduced with continuous development of technology for LPG engine. In the present study, spray-guided type direct injection combustion system, whose configuration is composed of direct injector in the vicinity of spark plug, was employed to realize stable lean combustion. A certain level of nitrogen oxides($NO_x$) emits due to a locally rich mixture regions in the stratified mixture. With the application of EGR system for the reduction of $NO_x$, 15% of $NO_x$ reduction was achieved whereas fuel consumption and hydrocarbon emission increased. By the application of EGR, the combustion speed reduced especially appeared at initial flame development period and peak heat release rates and increasing rates for heat release rate decreased as EGR rate increased due to the dilution effect of intake air.