Sung Bin Han

The Effect of Hydrogen Enrichment on Exhaust Emissions and Thermal Efficiency in a LPG fuelled Engine

The concept of hydrogen enriched LPG fuelled engine can be essentially characterized as low emissions and reduction of backfire for hydrogen engine. The purpose of study is obtaining low-emission and high-efficiency in LPG engine with hydrogen enrichment. In order to determine the ideal compression ratio, a variable compression ratio single cylinder engine was developed. The objective of this paper is to clarify the effects of hydrogen enriched LPG fuelled engine on exhaust emission, thermal efficiency and performance. The compression ratio of 8 was selected to minimize abnormal combustion. To maintain equal heating value, the amount of LPG was decreased, and hydrogen was gradually added. In a similar manner, the relative air-fuel ratio was increased from 0.8 to 1.3 in increment of 0.1, and the ignition timing was controlled to be at MBT each case.

A study on the characteristics of combustion with butane and propane in a retrofitted diesel engine

Abstract The purpose of this study was to investigate the characteristics of combustion and exhaust-gas temperature of a liquefied petroleum gas (LPG) engine when using butane and propane as fuel. A conventional diesel engine was modified into a LPG engine that utilized an LPG fuel system instead of a diesel fuel injection pump. The study was performed with different compositions of butane and propane, such as 100 per cent butane, 100 per cent propane, 50 per cent butane—50 per cent propane, 70 per cent butane—30 per cent propane, and 30 per cent butane—70 per cent propane. The major conclusions of this work are as follows: MBT spark ignition timing was similar with different butane/propane fuel blends, except at the 100 per cent butane, 1200 r/min condition; engine torque and power were not influenced by varying butane/propane fuel blends; and exhaust gas temperature was increased at higher engine speeds, and it was decreased by a maximum of 15 with different butane/propane fuel blends.

A study on the effect of operating conditions for the stability at idle

A gasoline engine with an electronically controlled fuel injection system has substantially better fuel economy and lower emissions than a carburetted engine. In general, the stability of engine operation is improved with fuel injector, but the stability of engine operation at idle is not improved compared with a carburetted gasoline engine. In addition, the increase in time that an engine is at idle due to traffic congestion has an effect on the engine stability and vehicle reliability. Therefore, in this research, we will study the influence of fuel injection timing, spark timing, dwell angle, and air-fuel ratio on engine stability at idle.

A numerical study of the effects of swirl chamber passage hole geometry on the flow characteristics of a swirl chamber type diesel engine

Abstract This research simulates the in-cylinder flow of a swirl chamber type diesel engine using a computational fluid dynamics (CFD) code and reveals the generation and distortion of swirling, tumbling vortices and their influence on turbulence kinetic energy depending on the shape, angle, and area of the jet passage. The CFD code was applied to the intake and compression processes. Results show that flow characteristics were affected by inflow velocity, which depends on the change in the jet passage shape. The swirl ratio was increased as a result of a decrease in the jet passage area. Turbulence kinetic energy was generated by mixing effects of the swirling and tumbling vortices.

Comparison study between mixer and liquefied petroleum injection system fuel supply methods in a heavy-duty single cylinder engine

Abstract The purpose of this study is to analyse the combustion and emission characteristics of a heavy-duty single cylinder engine (HDSCE) with a mixer and a liquefied petroleum injection (LPi) system. The mixer and LPi systems provide liquefied petroleum gas (LPG) in vapour and liquid phases throughout the intake manifold. Sensors such as the crankshaft position sensor (CPS) and Hall sensor supply spark and injection timing data to the ignition controller. An HDSCE runs at an engine speed of 800–1400 r/min, a compression ratio (CR) of 8, and a relative air-fuel ratio (Λ) value of 0.8–1.3. The major conclusions of this work include: LPi and mixer systems exhibit similar brake specific fuel consumption (b.s.f.c.) levels of 275g/kWh. Fuel efficiencies of LPi and mixer methods are almost identical. All these methods exhibit generally similar CO emission properties, and LPi wide-open throttle (WOT) and mixer WOT methods exhibit similar NOx emission properties.

An Experimental and Numerical Study of a Miller Cycle for a Gas Engine Converted From a Diesel Engine

Studies on internal combustion engines have made great efforts to develop engines with high efficiency for energy saving and emission gas reduction. The thermal efficiency of an internal combustion engine can be increased by expanding the pressure energy obtained through combustion to the maximum extent to convert the supplied thermal energy into work to the maximum extent. The cycle that can realize this goal is the Miller cycle. This Miller cycle converts the supplied thermal energy into mechanical energy to the maximum extent by making the expansion ratio greater than the compression ratio by changing the intake valve close timing. It is essential that study be performed for the development of the engine with high efficiency for energy saving in this era of rising oil prices. Therefore, this study realized a low compression and high expansion ratio engine by changing the intake valve close timing in order to investigate the characteristics of the Miller cycle. Furthermore, it confirmed that both the compression pressure and maximum combustion pressure increased through thermodynamic analysis. In addition, using the engine analysis program developed by the Ricardo Company known as WAVE, this study obtained the result that the output, torque and break thermal efficiency increased by 2 PS, 1.5kg and 2%, respectively at WOT (Wide Open Throttle) position and ABDC55° through simulation by changing the intake valve close timing.Copyright

Performance and exhaust emissions test results from a liquid propane injected engine with hydrogen enrichment

Abstract This paper investigates the effect of performance and exhaust emissions test results from a liquid propane injected engine with hydrogen enrichment. In order to research this topic, the test engine was run at 1400 rpm with a compression ratio of eight. Relative air—fuel varied between 0.8 and 1.3. CO emissions decreased with the addition of hydrogen, but the oxygen amount decreased around the rich and stoichiometric air—fuel ratio as the hydrogen supplement rate increased. CO emissions decreased with the increase in the hydrogen supplement rate. Total hydrocarbon emissions decreased as hydrogen was added in the rich and around stoichiometic air—fuel ratio. NOx emissions were maximum at around λ = 1.2 and the addition of 20 per cent hydrogen resulted in about a 20 percent increase in the amount of NO x emissions compared to that of pure LPG combustion. Power and thermal efficiency increased with the decrease of the hydrogen supplement rate.

Effect of engine variables on the turbulent flow of a spark ignition engine

The turbulent flow in a spark ignition engine plays an important role in determining its combustion characteristics and thermal efficiency. In order to analyse the combustion process, the turbulent flow and its turbulence intensity must be studied. To study the turbulent flow as varying various factors in a combustion chamber of a spark ignition engine, the L-head with or without squish area are selected. The turbulent as varying flow on the piston speed, inlet flow velocity, and squish velocity are measured by using hot wire anemometer. To examine the characteristics of turbulent flow, the ensemble averaged mean velocity, turbulence intensity, turbulence intensity decrease ratio, production rate of turbulence intensity, production coefficient of turbulence intensity are analysied.

A Study on the Performance and Emission Characteristics According to the Coolant Temperature of Combustion Chamber Head of Spark Ignition Engine Fuelled with Kerosene (Coal Oil)

A Study on the Performance and Emission Characteristics According to the Coolant Temperature of Combustion Chamber Head of Spark Ignition Engine Fuelled with Kerosene (Coal Oil) SUNG BIN HAN, YON JONG CHUNG Induk University, Department of Mechanical & Automotive Engineering, 12 Choansan-ro, Nowon-gu, Seoul 01878, Korea Dongguk University, Gyeongju Campus, Department of Mechanical Parts System Engineering, 123 Dongdae-ro, Gyeongju 38066, Korea

An Experimental Study on the Performance and Emission Characteristics of Diesel Engine Fuelled with a Blend of Ethanol

>> Alcohols are particularly attractive as alternative fuels because they are a renewable resource. This paper describes the performance and emission characteristics of ethanol and diesel blended fuels in a compression ignition engine. This experimental results showed that ethanol diesel blended fuels decreased the torque and brake mean effective pressure. And experimental results indicated that using ethanol-diesel blended fuel, smoke, CO and HC emissions decreased as a result of the ethanol addition.