• Journal of the korean Society of Automotive Engineers
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• v.8 no.1
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• pp.29-39
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• 1986

The purpose of this study is to develop an exhaust gas recirculation valve for reduction of the NOx emission of the gasoline engine. In this study the back pressure modulated(BPM) EGR system was developed and tested for the 1.6$\ell$ gasoline engine. By this system 50% of NOx emission was reduced at 7% EGR rate. Fuel consumption and CO emission were not affected by EGR but HC was increased up to the level of allowable limit. Overall operation was satisfactory. As a result of this study, the technics for developing EGR valve and adjusting the engine for EGR have been established.

• Journal of the korean Society of Automotive Engineers
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• v.12 no.6
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• pp.22-29
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• 1990

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.218-228
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• 1996

The behaviors of the mixture at the downstream of throttle valve in a TBI type gasoline engine plays a greater role in design of intake system. A good mixture has been influencing directly not only on the engine power but also on the pollutant emission. The mixture flow in an intake manifold is very complex, and the flow characteristics are varied with the valve type, valve angle, inlet air flow rate, and the other flow factors. Three kinds of valve are chosen in this study, and the informations of the mixture flow are observed experimentally using a PIV apparatus. Perforate valve has a smaller recirculation zone than the case of solid valve with a lower valve loss coefficient, and iti is verified that the perforated valve is also suitable to control the flow rate in a mixture flow system.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.127-133
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• 2008

Since the 1960's, exhaust gas recirculation(EGR) has been used effectively in spark ignition(SI) engines to control the exhaust emissions of the oxides of nitrogen(NOx). The most important requirements for the application of EGR systems to conventional SI engines are controllable flow rate and good dynamic response. In order to evaluate the characteristics of the electronic EGR valve, a test bench which is consisted of blower, heater, air flow meter and driving unit for electronic EGR valve was set up to simulate engine operating conditions. During the tests, the valve actuation parameters were controlled and the valve lifts and flow rates were measured to infer the characteristics of EGR valve. The results confirmed the capabilities of mathematical analysis and it seems that the correction for the valve lift and potentiometer output is necessary to achieve precise control of EGR rates.

• Journal of the Korean Society of Combustion
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• v.12 no.4
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• pp.22-30
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• 2007

The NOx emission characteristics were studied in an oscillating combustion burner equipped with a specially designed proportioning valve. The effects of various parameters on the NOx emission which are important in oscillating combustion were investigated. Also, the effects of coincident application of flue gas recirculation(FGR) were evaluated. The results show that oscillating combustion is an efficient tool for reducing NOx in the burner. Up to 53% of NOx reduction could be acquired in low frequency and small duty ratio conditions. The coincident application of FGR further reduced the NOx emission up to 74%. Thus, this study assured that oscillating combustion technology with FGR could be a fascinating method for NOx reduction in industrial burners.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.7
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• pp.967-975
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• 2000

Transient characteristics of a boiler and turbine system for a steam power plant are simulated. One-dimensional unsteady models are introduced for each component. An interaction between boiler and turbine and a control of the water level in the drum are taken into account. Transient responses of the system to the variations of main system variables such as fuel and air flow rate, cooling water injection rate at the attemperator, gas recirculation rate at the furnace and opening of the turbine control valve are examined. Effect of fluid inertia and tube wall thermal inertia on predicted dynamic behavior is investigated.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.1
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• pp.110-118
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• 2008

It is essential for the valid design of a marine flow-control valve to exactly know its flow characteristics. The present study has numerically investigated the flow characteristics inside a marine throttle-type globe valve using a kind of commercial CFD code, CFX10.0, with an adoption of the SST (Shear-Stress Transport) turbulence model. To validate the numerical approach, the flow coefficients are compared with the experimental ones. Results show that the globe valve is effective in the control of flow rate according to the opening ratio in case of the forward-direction flow, whereas it is effective in the flow shutoff in case of the reverse-direction flow. Around the inlet of the valve, a recirculation region is formed due to the blunt body shape, the turbulence intensity becomes strengthened and then an abrupt pressure loss occurs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.389-392
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• 2000

This paper presents a performance Analysis of electrically exhaust gas recirculation valve using commercial electromagnetic simulation software, Flux2D. Under the assumption of 2D axi-symmetric magnetic field, the characteristics of EEGR valve by revising the design parameter, has ken investigated by estimating the variation of thrust force with respect to the pintle position. The mode shapes and the frequency response functions were computed by using three dimensional finite element modeling of the whole EEGR valve and their accuracies were verified with experimental FFT analysis technique.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.5
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• pp.390-396
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• 2017

In this paper, an exact mathematical model is derived for an exhaust gas recirculation (EGR) valve actuator driven by an H-bridge converter. Particularly, a spring torque model of the EGR valve is proposed. The spring torque model is proposed by converting spring force and Coulomb frictional force in linear motion into a rotational torque. Moreover, a mechanical end-stop model was proposed by the valve mechanism. The accuracy of the proposed model is verified by comparing the experimental results with the simulated results.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.37-43
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• 2003

The exhaust gas recirculation (EGR) is needed for one of various strategies to reduce NOx emission. But to get the proper EGR rate, the intake and exhaust system become complicated, also application of EGR system is difficult because of the penalty in fuel consumption and the increase in particulate matter. This study is focused on the development of EGR valve using the electrical method. The effects of EGR on the characteristics of NOx, CO, CO2 emissions and particulate mater have been investigated using small-displacement size 0.8-liters engine of diesel passenger car operating at several loads and speeds. After the analysis and comparison between conventional E-EGR valve and developed E-EGR valve performance by test bench, the estimation of vehicle application was executed through the EGR map and CVS-75 test result measured on the chassis dynamometer.