Effect of Injection Pressure on Performance and Emission Characteristics HCCI Engines

Author(s):  
S. Gowthaman ◽  
G. Balamurugan

Homogeneous Charged Compression Ignition engine (HCCI) is a suitable replacement of conventional diesel engines as it provides higher thermal efficiency and low oxides of emission (NOx) and particulate emissions. In HCCI engine, direct controlling of ignition timing is not possible. But it can be controlled by varying the engine parameters such as fuel injection pressure, inlet air temperature and exhaust gas recirculation. In this study, HCCI engine is controlled with changing the injection pressure of the fuel and analysed for the effect of injection pressure of the fuel for emission and performance of Karanja methyl ester fuel. The experiments were conducted on HCCI engine with fuel injection pressures of 2 bar, 3 bar, 4 bar and 5 bar and the optimum fuel injection pressure is found out. The results show that, the brake thermal efficiency is increased when the injection pressure is increased due to better atomisation and fuel penetration and also resulted in low emissions (NOx, smoke) compared with diesel engine.

The purpose of this study is to investigate the effect of fuelinjection pressure onhomogeneous charge formation and performanceand emission characteristics of Homogeneous charge compression ignition engine. The fuel injection pressure isone of the primary parameter for improvingthe homogeneity of the mixture and governing the power output and emission characteristics of HCCI engine. In this investigation, diesel fuelwasinjected at different injection pressuresas 2bar, 3bar, 4bar and 5bar respectively throughbyport fuel injector. The experimental investigationsshow that increasing the fuel injection pressure will promote the fuel to penetrate with air and creates well pre mixedair/fuel charge.The result shows, the specific fuel consumption (SFC) of HCCI engine isslightlyhigherthan the SFC of conventional diesel engine.The HCCI engine with 3bar injection pressure operated engine has lower SFC values compared to other injection pressure operated HCCI engine.The brake thermal efficiency of HCCI engine, operated with 3barinjection pressure has maximum BTE values over the other injection pressure operated engine.From theresult, it is observed that HCCI engine has lower smoke density values compared to conventional diesel engine andfurther reducedby increasing the fuel injection pressure. The 3bar injection pressure operated HCCI engine has emitted lower smoke densitycompared to other injection pressure operated HCCI engine. The 3bar injection pressureoperated HCCIengine hasemittedmaximum oxides of nitrogen (NOx) emissions than the other injection pressure operated HCCI engine. Other exhaust emissions of carbon monoxide (CO) and hydrocarbon (HC)emissions are increased when compared toconvention diesel engine


2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Prabhakara Rao Ganji ◽  
Rajesh Khana Raju Vysyaraju ◽  
Srinivasa Rao Surapaneni ◽  
B. Karuna Kumar

AbstractIn recent years, engine emissions have been one of the important problems which are of great concern. Hence, there is a growing need to develop engines with reduced emission. In the present study, Variable Compression Ratio diesel engine model has been validated by comparing the simulation results with the experimental. The study is aimed at analyzing the effect of compression ratio, exhaust gas recirculation, fuel injection pressure and start of injection on engine performance and emission characteristics. Using composite desirability technique, the engine parameters have been optimized to achieve lower NOx, soot and ISFC. The optimum combination has been observed at Compression ratio 17.52, Start of injection −30.1 °aTDC, Fuel injection pressure 736.06 bar and Exhaust gas recirculation 28.29%. ISFC, NOx and soot are reduced by 2.37%, 29.11% and 83.81% respectively. Higher Target Fuel Distribution Index indicates the improved mixture homogeneity for the optimized parameters.


2017 ◽  
Vol 19 (3) ◽  
pp. 347-359 ◽  
Author(s):  
Felix Leach ◽  
Richard Stone ◽  
Dave Richardson ◽  
Andrew Lewis ◽  
Sam Akehurst ◽  
...  

Downsized, highly boosted, gasoline direct injection engines are becoming the preferred gasoline engine technology to ensure that increasingly stringent fuel economy and emissions legislation are met. The Ultraboost project engine is a 2.0-L in-line four-cylinder prototype engine, designed to have the same performance as a 5.0-L V8 naturally aspirated engine but with reduced fuel consumption. It is important to examine particle number emissions from such extremely highly boosted engines to ensure that they are capable of meeting current and future emissions legislation. The effect of such high boosting on particle number emissions is reported in this article for a variety of operating points and engine operating parameters. The effect of engine load, air–fuel ratio, fuel injection pressure, fuel injection timing, ignition timing, inlet air temperature, exhaust gas recirculation level, and exhaust back pressure has been investigated. It is shown that particle number emissions increase with increase in cooled, external exhaust gas recirculation and engine load, and decrease with increase in fuel injection pressure and inlet air temperature. Particle number emissions are shown to fall with increased exhaust back pressure, a key parameter for highly boosted engines. The effects of these parameters on the particle size distributions from the engine have also been evaluated. Significant changes to the particle size spectrum emitted from the engine are seen depending on the engine operating point. Operating points with a bias towards very small particle sizes were noted.


2019 ◽  
Vol 8 (3) ◽  
pp. 2383-2387

This Paper shows the effect of port fuel injection pressure of CNG in 3-cylinder SI Engine at Wide Open Throttle position using sequential port fuel injection system. All trials are performed on 4-stroke, 796 cc MPFI S.I engine at injection pressure of 2.0, 2.2, 2.4, 2.6, 2.8 bar for constant speed of 2500, 3000, 3500, 4000 & 4500 rpm. During the trial compression ratio is kept constant at 9.2 with Maximum Brake Torque (MBT) spark timing of 15oBTDC. Optimum torque is obtained for CNG at injection pressure of 2.6 bar and 3000 rpm. Gasoline trials are performed at same compression ratio for comparison with CNG at same injection pressure. Performance and emission characteristics with combustion analysis are performed at optimum injection pressure of 2.6 bar.


Author(s):  
Hoin Kang ◽  
Jerald A. Caton ◽  
Seangwock Lee ◽  
Seokhwan Lee ◽  
Seungmook Oh

LPG (Liquefied Petroleum Gas) has been widely used as an alternative fuel for gasoline and diesel vehicles in light of clean fuel and diversity of energy resources. But conventional LPG vehicles using carburetors or MPI fuel injection systems can’t satisfy the emissions regulations and CO2 targets of the future. Therefore, it is essential to develop LPG engines of spark ignition or compression ignition type such that LPG fuel is directly injected into the combustion chamber under high pressure. A compression ignition engine using LPG is the ideal engine with many advantages of fuel economy, heat efficiency and low CO2, even though it is difficult to develop due to the unique properties of LPG. This paper reports on numerical and experimental studies related to LPG fuel for a compression ignition engine. The numerical analysis is conducted to study the combustion chamber shape with CATIA and to analyze the spray and fluid behaviors with FLUENT for diesel and LPG (n-butane 100%) fuels. In one experimental study, a constant volume chamber is used to observe the spray formation for the chamber pressure 0 to 3MPa and to analyze the flame process, P-V diagram, heat release rate and emissions through the combustion of LPG fuel with the cetane additive DTBP (Di-tert-butyl peroxide) 5 to 15 wt% at 25MPa of fuel injection pressure. In engine bench tests, experiments were performed to find the optimum injection timing, lambda, COV and emissions for the LPG fuel with the cetane additive DTBP 5 to 15 wt% at 25MPa fuel injection pressure and 1500 rpm. The penetration distance of LPG (n-butane 100%) was shorter than that of diesel fuel and LPG was sensitive to the chamber pressure. The ignition delay was in inverse proportion to the ambient pressure linearly. In the engine bench tests, the optimum injection timing of the test engine to the LPG fuel with DTBP 15 wt% was about BTDC 12° CA at all loads and 1500 rpm. An increasing of DTBP blending ratio caused the promotion of flame and fast burn and this lead to reduce HC and CO emissions, on the other hand, to increase NOx and CO2 emissions.


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