Effect of Compression Ratio on the Performance Characteristics of a Palm Oil Methyl Ester Run Diesel Engine

Author(s):  
Biplab K. Debnath ◽  
Ujjwal K. Saha ◽  
Niranjan Sahoo

Palm Oil Methyl Ester (POME) is a very promising alternative renewable biofuel. This is because it has a better cetane number and a comparable lower calorific value with respect to its competitors. However, due to difference in molecular composition and hence dissimilar properties, it does not perform proficiently in diesel engine with standard design and operating parameters. Therefore, a study is arranged to realize the effect of compression ratio variation on POME run in diesel engine. The load is varied from ‘no load’ to ‘full load’ with six equal intervals. During this study, standard diesel injection timing is maintained unaffected. The study conveys that at higher compression ratio, POME causes reduction in brake fuel consumption and thereby increases the engine efficiency. The increase in compression ratio also causes smoother combustion, lower ignition delay with early heat release than diesel operation. The detrimental emission quantities in the form of carbon monoxide, oxides of nitrogen and hydrocarbon emissions are also cut down with presence of POME in the diesel engine at high compression ratio. Thus, POME can be regarded as a good alternative fuel for diesel engine for locomotive applications.

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2644 ◽  
Author(s):  
Norhidayah Mat Taib ◽  
Mohd Radzi Abu Mansor ◽  
Wan Mohd Faizal Wan Mahmood

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.


2014 ◽  
Vol 592-594 ◽  
pp. 1632-1637
Author(s):  
Ramalingam Senthil ◽  
C. Paramasivam ◽  
Rajendran Silambarasan

Nerium methyl ester, an esterified biofuel, has an excellent cetane number and a reasonable calorific value. It closely resembles the behaviour of diesel. However, being a fuel of different origin, the standard design limits of a diesel engine is not suitable for Nerium methyl ester (NME). Therefore, in this work, a set of design and operational parameters are studied to find out the optimum performance of Nerium methyl ester run diesel engine. This work targets at finding the effects of the engine design parameter viz. fuel injection pressure (IP) on the performance with regard to specific fuel consumption (SFC), brake thermal efficiency (BTHE) and emissions of CO, CO2, HC, NOxwith N20 as fuel. Comparison of performance and emission was done for different values of injection pressure to find best possible condition for operating engine with NME. For small sized direct injection constant speed engines used for agricultural applications, the optimum injection pressure was found as 240bar.Methyl esters from Nerium, with properties close to diesel; show better performance and emission characteristics. Hence Nerium (N20) blend can be used in existing diesel engines without compromising the engine performance. Diesel (25%) thus saved will greatly help the interests of railways in meeting the demand for fuel,as diesel trains are operated at maximum load condition.


Author(s):  
Yousef Haik ◽  
Mohamed Y. E. Selim ◽  
Taher Abdulrehman

An experimental study has been carried to use raw Algae oil and its methyl esters in an indirect injection diesel engine. Effects of engine speed, engine load output, injection timing of the algae biofuel and engine compression ratio on the engine output torque, combustion noise (maximum pressure rise rate), maximum pressure and maximum heat release rate have been studied. Raw oil extracted from microalgae and its methyl ester have been evaluated in a Ricardo E6 engine. It has been shown that the algae oil methyl ester’s properties are similar to diesel fuel and its use has been successful in running the diesel engine smoothly. However, its use reduced the engine output torque slightly and increased the combustion noise. Nonetheless, the engine output can be increased and the combustion noise can be reduced by controlling the engine design parameters e.g. injection timing and compression ratio.


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