A Study on the Effects of a Higher Compression Ratio in the Combustion Chamber on Diesel Engine Performance

2016 ◽  
Author(s):  
Yoshihiro Funayama ◽  
Hiroshi Nakajima ◽  
Kiyohiro Shimokawa
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Compression Ratio ◽  
Engine Performance

scholarly journals Comparison of the Emissions, Noise, and Fuel Consumption Comparison of Direct and Indirect Piezoelectric and Solenoid Injectors in a Low-Compression-Ratio Diesel Engine

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4023 ◽  
Author(s):  
Stefano d’Ambrosio ◽  
Alessandro Ferrari ◽  
Alessandro Mancarella ◽  
Salvatore Mancò ◽  
Antonio Mittica
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Injection ◽  
Engine Performance ◽  
Combustion Noise ◽  
Driving System ◽  
Performance And Emissions ◽  
Direct Acting ◽  
Engine Performance And Emissions

An experimental investigation has been carried out to compare the performance and emissions of a low-compression-ratio Euro 5 diesel engine featuring high EGR rates, equipped with different injector technologies, i.e., solenoid, indirect-acting, and direct-acting piezoelectric. The comparisons, performed with reference to a state-of-the-art double fuel injection calibration, i.e., pilot-Main (pM), are presented in terms of engine-out exhaust emissions, combustion noise (CN), and fuel consumption, at low–medium engine speeds and loads. The differences in engine performance and emissions of the solenoidal, indirect-acting, and direct-acting piezoelectric injector setups have been found on the basis of experimental results to mainly depend on the specific features of their hydraulic circuits rather than on the considered injector driving system.

scholarly journals Modification of a Direct Injection Diesel Engine in Improving the Ignitability and Emissions of Diesel–Ethanol–Palm Oil Methyl Ester Blends

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2644 ◽  
Author(s):  
Norhidayah Mat Taib ◽  
Mohd Radzi Abu Mansor ◽  
Wan Mohd Faizal Wan Mahmood
Keyword(s):  
Diesel Engine ◽  
Methyl Ester ◽  
Ambient Temperature ◽  
Palm Oil ◽  
Compression Ratio ◽  
Direct Injection ◽  
Cetane Number ◽  
Engine Performance ◽  
Injection Timing ◽  
Injection Strategies

Blending diesel with biofuels, such as ethanol and palm oil methyl ester (PME), enhances the fuel properties and produces improved engine performance and low emissions. However, the presence of ethanol, which has a small cetane number and low heating value, reduces the fuel ignitability. This work aimed to study the effect of injection strategies, compression ratio (CR), and air intake temperature (Ti) modification on blend ignitability, combustion characteristics, and emissions. Moreover, the best composition of diesel–ethanol–PME blends and engine modification was selected. A simulation was also conducted using Converge CFD software based on a single-cylinder direct injection compression ignition Yanmar TF90 engine parameter. Diesel–ethanol–PME blends that consist of 10% ethanol with 40% PME (D50E10B40), D50E25B25, and D50E40B10 were selected and conducted on different injection strategies, compression ratios, and intake temperatures. The results show that shortening the injection duration and increasing the injected mass has no significant effect on ignition. Meanwhile, advancing the injection timing improves the ignitability but with weak ignition energy. Therefore, increasing the compression ratio and ambient temperature helps ignite the non-combustible blends due to the high temperature and pressure. This modification allowed the mixture to ignite with a minimum CR of 20 and Ti of 350 K. Thus, blending high ethanol contents in a diesel engine can be applied by advancing the injection, increasing the CR, and increasing the ambient temperature. From the emission comparison, the most suitable mixtures that can be operated in the engine without modification is D50E25B25, and the most appropriate modification on the engine is by increasing the ambient temperature at 350 K.

Variable Compression Ratio Diesel Engine Performance Analysis

2015 ◽  
Vol 28 (1) ◽  
pp. 6-12 ◽  
Author(s):  
K.Satya narayana ◽  
◽  
Vinodh Kumar Padala ◽  
T.V.Hanumantha Rao ◽  
S.V.Umamahe swararao
Keyword(s):  
Diesel Engine ◽  
Performance Analysis ◽  
Compression Ratio ◽  
Engine Performance ◽  
Variable Compression Ratio ◽  
Variable Compression

A Theoretical Study of a Variable Compression Ratio Turbocharged Diesel Engine

1992 ◽  
Vol 206 (4) ◽  
pp. 227-238 ◽  
Author(s):  
T J Rychter ◽  
A Teodorczyk ◽  
C R Stone ◽  
H J Leonard ◽  
N Ladommatos ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Compression Ratio ◽  
Engine Performance ◽  
Expansion Ratio ◽  
Combustion Noise ◽  
Connecting Rod ◽  
Turbocharged Diesel Engine ◽  
Variable Compression Ratio ◽  
Engine Simulation ◽  
Variable Compression

A variable compression ratio concept that can give a different expansion ratio to the compression ratio has been evaluated by means of a simulation of a turbocharged diesel engine. The compression ratio is controlled by varying the ratio of the connecting rod length to the crank throw, hence the name variable crank radius/connecting rod length engine (VR/LE). The VR/LE mechanism kinematics have been defined and described, and the compression ratio and expansion ratio have been presented as a function of the eccentric phase angle (αo). A zero-dimensional engine simulation that has been the subject of comprehensive validation has been used as the basis of the VR/LE study. The effect of the compression ratio on the engine performance at fixed loads is presented. The principal benefits are a reduction in fuel consumption at part load of about 2 per cent and a reduction in ignition delay that leads to an estimated 6 dB reduction in combustion noise. The study has been conducted within the assumption of a maximum cylinder pressure of 160 bar.

scholarly journals Injection and Combustion of RME with Water Emulsions in a Diesel Engine

10.14311/1169 ◽  
2010 ◽  
Vol 50 (2) ◽  
Author(s):  
J. Cisek
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Flow Reactor ◽  
Flame Temperature ◽  
Pressure Rise ◽  
Engine Performance ◽  
Exponential Relationship ◽  
Water Fraction

This paper presents ways of using the fully-digitised triggerable AVL VideoScope 513D video system for analysing the injection and combustion inside a diesel engine cylinder fuelled by RME with water emulsions.The research objects were: standard diesel fuel, rapeseed methyl ester (RME) and RME – water emulsions. With the aid of a helical flow reactor, stable emulsions with the water fraction up to 30 % weight were obtained, using an additive to prevent the water from separating out of the emulsion.An investigation was made of the effect of the emulsions on exhaust gas emissions (NOX, CO and HC), particulate matter emissions, smoke and the fuel consumption of a one-cylinder HD diesel engine with direct injection. Additionally, the maximum cylinder pressure rise was calculated from the indicator diagram. The test engine was operated at a constant speed of 1 600 rpm and 4 bar BMEP load conditions. The fuel injection and combustion processes were observed and analysed using endoscopes and a digital camera. The temperature distribution in the combustion chamber was analysed quantitatively using the two-colour method. The injection and combustion phenomena were described and compared.A way to reduce NOX formation in the combustion chamber of diesel engines by adding water in the combustion zone was presented. Evaporating water efficiently lowers the peak flame temperature and the temperature in the post-flame zone. For diesel engines, there is an exponential relationship between NOX emissions and peak combustion temperatures. The energy needed to vaporize the water results in lower peak temperatures of the combusted gases, with a consequent reduction in nitrogen oxide formation. The experimental results show up to 50 % NOX emission reduction with the use of 30% water in an RME emulsion, with unchanged engine performance.

Air supply system design of a Diesel–Brayton combined cycle engine

2018 ◽  
Vol 233 (4) ◽  
pp. 545-555
Author(s):  
Yuzhi Jin ◽  
Yuping Qian ◽  
Yangjun Zhang ◽  
Weilin Zhuge
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Operation Mode ◽  
Three Dimensional ◽  
Engine Performance ◽  
Supply System ◽  
Combined Cycle ◽  
Air Supply ◽  
Startup Performance

The Diesel–Brayton combined cycle engine was proposed previously to achieve the goal of lower fuel consumption, higher power density and good startup performance under low-temperature conditions. The prototype engine was designed and tested based on an off-the-shelf gas turbine and a diesel engine. To achieve a more compact and lighter design, the air supply system was designed based on the centrifugal compressor of the gas turbine. In the coupling operation mode aiming to generate the maximum power, a large amount of compressed air must be extracted into the diesel engine. The present paper presents the design methodology of the compact air supply system. The bleeding slot configuration was selected based on a parametric study and proven by systematic experiments. Three-dimensional simulations were conducted to investigate the performance and flow field of the compressor. Backflow appeared in several passages of the axial diffuser caused by air bleeding, which further distorted the air flow in the combustion chamber. Such distortion may cause compressor and combustion instabilities. In the future, the combustion chamber and the axial diffuser must be designed in combination with an air bleeding system to improve the engine performance.

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