• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.1 no.1
• /
• pp.95-103
• /
• 2001

The purpose of Introducing a combined cycle with gas turbine in power plants is to reduce losses of energy, by effectively using exhaust gases from the gas turbine to produce additional electricity or process. The efficiency of a combined power plant with the gas turbine increases, exceeding 50%, while the efficiency of traditional steam turbine plants is approximately 35% to 40%. Up to the present time, the PID controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain without any experience, since the gain of the PID controller has to be manually tuned by trial and error procedures. This paper focuses on the neural network tuning of the 2-DOF PID controller with a combined 2-DOF parameter (NN-Tuning 2-DOF PID controller), for optimal control of the Gun-san gas turbine generating plant in Seoul, Korea. In order to attain optimal control, transfer function and operating data from start-up, running, and stop procedures of the Gun-san gas turbine have been acquired and a designed controller has been applied to this system. The results of the NN-Tuning 2-DOF PID are compared with the PID controller and the conventional 2-DOF PID controller tuned by the Ziegler-Nichols method through experimentation. The experimental results of the NN-Tuning 2-DOF PID controller represent a more satisfactory response than those of the previously-mentioned two controllers.

• 한국전산유체공학회:학술대회논문집
• /
• 1995.10a
• /
• pp.76-81
• /
• 1995

A numerical procedure for the analysis of transient behavior in a monolithic catalytic converter is presented. The thermal behavior of a monolithic catalytic converter is fully coupled with mass transfer and exothermic reaction between exhaust gases and the catalytic converter. In the present study, all these processes are solved simultaneously. The heat transfer process is approximated by combinging one dimensional convection and conduction and the chemical reaction is also simply modelled by using the concepts of reaction rate and reaction heat. All the partial diffenrential equations for the heat transfer, mass transfer and chemical reactions are appximated by using finite volume method. Resulting algebraic equations are solved using the Newton's method. To see the workability of present numerical method, two well known problems, say step increase and step decrease in the gas inlet temperature, have been calculated. Comparion of present solutions with previous solutions shows a good agreement.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.11
• /
• pp.1578-1584
• /
• 2002

Combustion stability is one of the most important factors that must be considered in burning of heavy fuel oil, especially low-grade oil. This paper describes the combustion characteristics of petrochemical process by- product in the combustion furnace of heavy fuel oil. Main experimental parameters were combustion load, excess 02, fuel preheating temperature and air/fuel ratio. The capacity of CRF(combustion research facility) used in this study was 1.0 ton/hr and the burner is steam jet type suitable far heavy oil combustion and manufactured by UNIGAS in Italy. The fuel used in this experiment were 0.5 B-C, petrochemical process by-product and 3 kinds of 0.5 B-C/process by-product mixtures. The combustion stability was monitored and exhaust gases such as CO, NOx, SOx and particulates were measured with the excess $O_2$ and combustion load. The main purpose of this study is to clarify whether process by-product can be used as a boiler fuel or not in consideration of flame stability and emission properties.

• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.3
• /
• pp.373-377
• /
• 2009

It is well known that SOx and NOx concentration has a considerable influence on the $N_2O$ emission of the greenhouse gas properties. The quantity of SOx generated during combustion, on fuel specific basis, is directly related to the sulfur content of the fuel oil. However, restricting the fuel oil sulfur content is only a partial response to limiting the overall quantity of SOx emissions, as there remains no over control on the fuel oil consumption other than the commercial pressure which have always directed the attention. This study was carried out as a new basic experiment method of emission control, manly targeted to the vessel. In the experiment, where the scrubbing was achieved through spray tower with high alkaline water made from the electrolysis of seawater, the combined action was to neutralize the exhaust gases (SOx, PM, CO etc.), dilute it, and wash it out. The results showed that SOx reduction of around 95 percent or over could be achieved when using in the high alkaline water, and also leaded to a reduction in the stability of the each pollutant components including the PM (Particulate Matter). The results suggest that the seawater electrolysis method has a very effective reduction of emissions without heavy cost, or catalysts particularly on board.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.5
• /
• pp.525-531
• /
• 2011

Recently, the demand of environmentally friendly transportation has increased due to the environmental issues. Electric two-wheeled vehicles do not have the noise pollution nor exhaust gases of vehicles with internal combustion engines. Performance evaluation of an electric two-wheeled vehicle was carried out. A driving test on outdoor roads was performed and a chassis dynamometer was used. The chassis dynamometer simulates the road load of the vehicle. The road load influences the tests using the chassis dynamometer. The differences between the table method and the coasting test for setting the road load was compared and analyzed.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.3 no.3
• /
• pp.53-61
• /
• 1999

Impinging jets are observed when exhaust gases from missiles or V/STOL aircrafts impinge on the ground, flame deflector, ship deck, etc. The flow shows different patterns according to the nozzle geometry, nozzle-to-plate distance, and plate angle, for example. This paper describes experimental works on the phenomena (pressure distribution, occurrence of stagnation bubble, and so on.) when underexpanded supersonic jets impinge on a perpendicular flat plate using a supersonic cold-flow system, and compares the results with those obtained using a shock tunnel. The flow characteristics for the supersonic cold-flow system were also investigated. Surface pressure distribution of supersonic cold-flow system differed from that of shock tunnel because of water and temperature in the low-pressure chamber. Surface pressure distribution as to underexpanded ratio showed similar patterns together.

• Journal of Power System Engineering
• /
• v.18 no.5
• /
• pp.35-41
• /
• 2014

The wood pellet, which is one of the woody biomass energy, has very high economic efficiency and combustion efficiency during their combustion. The existing pellet burner have many problems such as low combustion efficiency, flame stabilization, ash problem and ignition time etc. We developed cyclonic wood pellet burner aim to 20,000kcal/hr boiler and measured temperature profiles and exhaust gases in order to investigate the flame stability and optimum combustion condition at any air flow conditions. As results, we confirmed the reappearance and the isotropy of the experimental results in the burner. At the first air flow inlet condition of excess air ratio ${\alpha}=0.02$, second air flow $490{\ell}/min$ had the best combustion condition when pellet supplied 30g. This result means that we need much air supply only for the swirling of second air flow. So we tested various second air flux at first air excess air ratio ${\alpha}=0.7$ condition. At this condition, we could find out that we don't need much second air and total air flux compared to the former condition. We will continuously test this work of air flow distribution, and swirl effect of first air flow, and ash elimination.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.12
• /
• pp.1722-1728
• /
• 2002

Most researches regarding emulsified fuel were in the areas of emulsifier, emulsified fuel manufacturing and emulsified fuel droplet combustion, but there were little papers published regarding emulsified fuel combustion and boiler efficiency in an industrial boiler. The main purpose of this study is to clarify whether improvements in the boiler efficiency and the reduction of pollutants such as CO, NOx, SOx and smoke exist or not when emulsified fuels are combusted in the commercial boiler. Main experimental parameters were water content in heavy oil , excess $O_2$, and boiler load. The fuels used in this experiment were 0.5 B-C, and 5 kinds of 0.5 B-C/water emulsified fuels. The combustion characteristics of heavy oil and its emulsions with water were investigated in an industrial boiler. The combustion stability was monitored and exhaust gases such as CO, NOx, SOx and smoke were measured with excess $O_2$ and combustion load. In case of emulsified fuel combustion, flame stability was poor and boiler efficiency was lowered by 1.6~5.7%, but emission levels of CO and smoke were improved.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.5
• /
• pp.68-76
• /
• 2007

It is strongly requested to reduce fuel consumption because of high oil price and exhaust gases of road vehicles for environmental preservation. To solve these problems, several types of hybrid vehicles have been developed. Among them, flywheel hybrid vehicle using variable displacement pump/motor was already proposed as one of the feasible hybrid systems in place of hybrid vehicle by the conventional storage battery. The proposed flywheel hybrid vehicle is to keep constant pressure of high pressure line by the control of swash plate angle of flywheel pump/motor as pressure compensator. The efficiency of the overall system depends severely on the efficiency of hydraulic pump/motor in the energy saving hydraulic control system by simulation. According to the control methods of swash plate angle of piston pump/motor, there remain several problems to be solved. In this paper, experimental setup for energy saving is fabricated and the efficiency of energy saving is investigated by experiments with respect to various experimental conditions.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.23 no.2
• /
• pp.169-177
• /
• 2015

In this study we investigated the regeneration methods for the lean $NO_x$ trap (LNT) catalyst in a 2.2L direct injection diesel engine. The regeneration methods were 1) in-cylinder post fuel injection and 2) external fuel injection strategy. The in-cylinder post fuel injection method uses in-cylinder injectors with the addition of the post fuel injection to supply enough reductants such as CO, $H_2$, THC. The external fuel injection method was enabled by installing a fuel injector with a wide spray angle before the LNT catalyst. Through the engine experiment, the $NO_x$ conversion efficiency, the amount of reductant exhaust gases, fuel consumption, and temperature behavior in the LNT catalyst were evaluated and compared for the two regeneration methods.