Effects of Boost Pressure on Piston Lubrication of Diesel Engine

Author(s):  
Masaaki Takiguchi ◽  
Yohei Yoshiga ◽  
Mohd Sofwam bin Lukman

The state of piston lubrication-has been determined with reference to piston friction force measured by our developed single-cylinder supercharged small bore diesel engine with a boost pressure of up to 150kPa. The result is that the state of lubrication deteriorates markedly immediately before the compression top dead center due to increased boost pressure and immediately after the compression top dead center due to increased engine load. Moreover, the crankshaft offset, piston pin offset and multi-grade oil further deteriorate piston lubrication with a boost pressure.

Author(s):  
Wei Fang ◽  
David B. Kittelson ◽  
William F. Northrop ◽  
Junhua Fang

Dual-fuel reactivity-controlled compression ignition (RCCI) combustion using port injection of a less reactive fuel and early-cycle direct injection of a more reactive fuel has been shown to yield both high thermal efficiency and low NOX and soot emissions over a wide engine operating range. Conventional and alternative fuels such as gasoline, natural gas and E85 as the lower reactivity fuel in RCCI have been studied by many researchers; however, published experimental investigations of hydrous ethanol use in RCCI are scarce. Making greater use of hydrous ethanol in internal combustion engines has the potential to dramatically improve the economics and life cycle carbon dioxide emissions of using bio-ethanol. In this work, an experimental investigation was conducted using 150 proof hydrous ethanol as the low reactivity fuel and commercially-available diesel as the high reactivity fuel in an RCCI combustion mode at various load conditions. A modified single-cylinder diesel engine was used for the experiments. Based on previous studies on RCCI combustion by other researchers, early-cycle split-injection strategy of diesel fuel was used to create an in-cylinder fuel reactivity distribution to maintain high thermal efficiency and low NOX and soot emissions. At each load condition, timing and mass fraction of the first diesel injection was held constant, while timing of the second diesel injection was swept over a range where stable combustion could be maintained. Since hydrous ethanol is highly resistant to auto-ignition and has large heat of vaporization, intake air heating was needed to obtain stable operations of the engine. The study shows that 150 proof hydrous ethanol can be used as the low reactivity fuel in RCCI through 8.6 bar IMEP and with ethanol energy fraction up to 75% while achieving simultaneously low levels of NOX and soot emissions. With increasing engine load, less intake heating is needed and EGR is required to maintain low NOX emissions. Future work will look at stability of hydrous ethanol RCCI at higher engine load.


2019 ◽  
Vol 179 (4) ◽  
pp. 32-39
Author(s):  
Yuzo AOYAGI

To reduce exhaust NOx and smoke, it is important to measure flame temperature and soot amount in combustion chamber. In diesel combustion it is effective to use the two-color method for the measurement of the flame temperature and KL factor, which is related with soot concentration. The diesel flame was directly and continuously observed from the combustion chamber at running engine condition by using a bore scope and a high-speed video camera. The experimental single cylinder engine has 2.0-liter displacement and has the ability with up to five times of the boost pressure than the naturally aspirated engine by external super-charger. The devices of High Boost, Wide Range and High EGR rate at keeping a relatively high excess air ratio were installed in this research engine in order to reduce exhaust NOx emission without smoke deterioration from diesel engines. The video camera nac GX-1 was used in this study. From observed data under the changing EGR rates, the flame temperature and KL factor were obtained by the software of two-color method analysis. The diesel combustion processes are understood well by analyzing high-speed movies of the diesel flame motion and its temperature. The NOx and smoke are mutually related to maximum flame temperature and also it is possible to reduce simultaneously both NOx and soot emissions by high EGR rate in a single cylinder diesel engine.


2012 ◽  
Vol 588-589 ◽  
pp. 344-348
Author(s):  
Pankaj N. Shrirao ◽  
Parvezalam I. Shaikh ◽  
Farazuddin Zafaruddin ◽  
A.N. Pawar

Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al2O3.2SiO2(mullite) (Al2O3= 60%, SiO2= 40%) over a 150 µm thickness of NiCrAlY bond coat. The working conditions for the conventional engine (without coating) and LHR (mullite coated) engine were kept exactly same to ensure a comparison between the two configurations of the engine. This paper is intended to emphasis on emission characteristics of diesel engine with and without mullite coating under identical conditions. Tests were carried out at same operational constraints i.e. air-fuel ratio and engine speed conditions for both conventional engine (without coating) and LHR (mullite coated) engines. The results showed that, there was as much as29.41% and 24.35% decreasing on CO and HC emissions respectively for LHR (mullite coated) engine compared to conventional engine (without coating) at full load. The average decrease in smoke density in the LHR engine compared with the conventional engine was 13.82 % for full engine load. However, there was as much as 20% increasing on NOx emission for LHR engine compared to conventional engine at full load. Also the results revealed that, there was as much as 22% increasing on exhaust gas temperature for LHR engine compared to conventional engine at full engine load.


2021 ◽  
pp. 146808742110667
Author(s):  
Jayaraman Ramkumar ◽  
Anand Krishnasamy ◽  
A Ramesh

Single-cylinder diesel engines are generally not turbocharged because of highly pulsating exhaust gas flow, resulting in increased speed fluctuations and reduced turbine performance. In the present work, a novel and simple method is proposed wherein an exhaust plenum is placed before the turbine to reduce the flow fluctuations. A production light-duty naturally aspirated (NA) diesel engine modified into the turbocharged version was incorporated with an exhaust plenum. Steady-state experiments were performed with the base naturally aspirated engine, the turbocharged version without an exhaust plenum (conventional pulse turbocharging), and the turbocharged version with the exhaust plenum. The present work attempts to establish the limitations of conventional pulse turbocharging in a single-cylinder diesel engine unavailable in the existing literature. Though the conventional pulse turbocharged version could deliver a boost pressure of about 2 bar (absolute), a brake power reduction of 40% and the associated drop in brake mean effective pressure was observed compared to the base NA engine due to high exhaust back pressures. The pumping work was four times higher in conventional pulse turbocharging than the NA engine, thus reducing the performance. After validating the simulation models, a one-dimensional simulation tool was used to evaluate the effect of incorporating exhaust plenum before the turbine. Simulated results predicted the brake power output within a 3% error for the NA and plenum turbocharging configurations. An optimal plenum volume was arrived at using the validated simulation model. Subsequent experiments on the turbocharged engine with the plenum in place showed a significant improvement in the engine performance and reduced exhaust emissions compared to the NA version. Brake power output was enhanced by 25%, which indicated improved thermal efficiency of 2%. Compared to the NA version, the soot, carbon monoxide (CO) and unburned hydrocarbon HC emissions were reduced by 93%, 88%, and 53%, respectively. However, an increase in oxides of nitrogen (NOx) emissions was seen, which can be controlled with suitable mitigation methods taking advantage of the significantly lower soot levels. Thus, the proposed method of placing an exhaust plenum before the turbine makes turbocharging viable on single-cylinder diesel engines with performance improvement and emission reduction when suitable NOx mitigation measures are adopted.


2021 ◽  
Vol 2 (1) ◽  
pp. 15-24
Author(s):  
Ishwar Joshi ◽  
Surya Prasad Adhikari

 In this study, biodiesel from the stem of Pinus roxburghii was prepared by steam distillation process. Consequently, the physical and thermal properties of pine biodiesel (P100), and 20 % pine-biodiesel and 80 % diesel (P20) were tested on American Society for Testing and Materials (ASTM) standards. The test results confirmed that the thermophysical properties of pine biodiesel and its blend were suitable for the fuel in diesel engine without any modification in the test engine. Eventually, the engine performance and combustion parameters were evaluated for pine-biodiesel blend for 5 % biodiesel and 95 % diesel (P5), 10 % biodiesel and 90 % diesel (P10), 15 % biodiesel and 85 % diesel (P15) and P20, and compared with diesel on Kirloskar Single Cylinder Compression Ignition Engine for a compression ratio of 15:1. In the midst of those in different blends evaluated, P15 showed the better brake specific fuel consumption (BSFC) i.e 18.75 % lower than diesel fuel particularly up to 50 % of the engine load. However, at higher load, decrease rate in BSFC of P15 fuel is lower than engine load up to 50 %. Similarly, brake thermal efficiency (BTE) of P15 increases to 13.5% mainly on 50 % loading condition of the engine. At above, increment rate of BTE of pine oil biodiesel compared to diesel decreases. The brake power (BP) and brake mean effective pressure (BMEP) of P15 also found nearer to diesel. However, the BP of P15 found higher compared to diesel in all loading conditions. Thus, from the experimental investigations, P15 blend of pine oil biodiesel was found to be amenable for its use in compression ignition (CI) engine without any modification, as the BTE and SFC were found to better and, BP, indicated power (IP) and BMEP were also found nearer to diesel fuel.


Author(s):  
Erdiwansyah ◽  
Mahidin ◽  
Ahmad Fitri Yusop ◽  
Muhammad Zaki ◽  
Rizalman Mamat ◽  
...  

Energy demand from the community, which continues to increase has resulted in depletion of petroleum (fossil) energy in recent years. Many researchers have sought to find alternative fuels to replace dependence on conventional energy. The mixing of alcohol into diesel fuel has also been carried out by several previous researchers. The main focus of this research is to investigate the combustion performance of diesel engines using a mixture of biodiesel-butanol-water and diesel (B5Bu5W5). This research experiment used a single-cylinder diesel engine with different speeds at 25% and 50% engine load. The experimental results show that the maximum cylinder pressure reaches 72.32 bar when the engine load reaches 50%. While at 25% engine load press the maximum cylinder 33.62 bar. The heat dissipation for 50% engine load is also higher than the engine load 25% respectively 34.39% and 33.62%. Overall results show that cylinder pressure increases when the load and engine speed increase. However, the combustion time is a little slower than when using pure diesel fuel.


Author(s):  
M. A. Adzmi ◽  
A. Abdullah ◽  
Z. Abdullah ◽  
A. G. Mrwan

Evaluation of combustion characteristic, engine performances and exhaust emissions of nanoparticles blended in palm oil methyl ester (POME) was conducted in this experiment using a single-cylinder diesel engine. Nanoparticles used was aluminium oxide (Al2O3) and silicon dioxide (SiO2) with a portion of 50 ppm and 100 ppm. SiO2 and Al2O3 were blended in POME and labelled as PS50, PS100 and PA50, PA100, respectively. The data results for PS and PA fuel were compared to POME test fuel. Single cylinder diesel engine YANMAR TF120M attached with DEWESoft data acquisition module (DAQ) model SIRIUSi-HS was used in this experiment. Various engine loads of zero, 7 N.m, 14 Nm, 21 N.m and 28 N.m at a constant engine speed of 1800 rpm were applied during engine testing. Results for each fuel were obtained by calculating the average three times repetition of engine testing. Findings show that the highest maximum pressure of nanoparticles fuel increase by 16.3% compared to POME test fuel. Other than that, the engine peak torque and engine power show a significant increase by 43% and 44%, respectively, recorded during the PS50 fuel test. Meanwhile, emissions of nanoparticles fuel show a large decrease by 10% of oxide of nitrogen (NOx), 6.3% reduction of carbon dioxide (CO2) and a slight decrease of 0.02% on carbon monoxide (CO). Addition of nanoparticles in biodiesel show positive improvements when used in diesel engines and further details were discussed.  


2021 ◽  
Vol 11 (15) ◽  
pp. 6749
Author(s):  
Zhifeng Xie ◽  
Ao Wang ◽  
Zhuoran Liu

The cooling system is an important subsystem of an internal combustion engine, which plays a vital role in the engine’s dynamical characteristic, the fuel economy, and emission output performance at each speed and load. This paper proposes an economical and precise model for an electric cooling system, including the modeling of engine heat rejection, water jacket temperature, and other parts of the cooling system. This model ensures that the engine operates precisely at the designated temperature and the total power consumption of the cooling system takes the minimum value at some power proportion of fan and pump. Speed maps for the cooling fan and pump at different speeds and loads of engine are predicted, which can be stored in the electronic control unit (ECU). This model was validated on a single-cylinder diesel engine, called the DK32. Furthermore, it was used to tune the temperature of the water jacket precisely. The results show that in the common use case, the electric cooling system can save the power of 255 W in contrast with the mechanical cooling system, which is about 1.9% of the engine’s power output. In addition, the validation results of the DK32 engine meet the non-road mobile machinery China-IV emission standards.


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