Mostrando ítems 1-3 de 3

Combustion and performance study of low-displacement compression ignition engines operating with Diesel–Biodiesel blends

Valencia, Guillermo; Acevedo Peñaloza, Carlos Humberto; Duarte Forero, Jorge (Applied SciencesSuiza, 2020-01-30)

This study investigated the influence of different biodiesel blends produced from residual sunflower oil and palm oil from agroindustry liquid waste on the characteristics of the combustion process, performance, and emissions ...
Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines

Hernández Comas, Brando; Maestre Cambronel, Daniel Esteban; Pardo García, Carlos Eduardo; FONSECA VIGOYA, MARLEN DEL SOCORRO; Pabón León, Jhon (LubricantsSuiza, 2021-03-02)

Internal combustion engines are widely implemented in several applications; however, they still face significant challenges due to the sealing capacity of the compression rings. Gas leakage through the crankcase, also ...
Study of the piston secondary movement on the tribological performance of a single cylinder low-displacement diesel engine

Duarte Forero, Jorge; Valencia, Guillermo; PALACIOS ALVARADO, WLAMYR (LubricantsSuiza, 2020-10-30)

The present study aims to analyze the secondary movement of the piston considering the deformations present in the piston skirt, the hydrodynamic lubrication, and the effects of the clearances in the connecting rod bearings. ...

Envíos recientes

Combustion and performance study of low-displacement compression ignition engines operating with Diesel–Biodiesel blends
...
Valencia, Guillermo | 2020-01-30

This study investigated the influence of different biodiesel blends produced from residual sunflower oil and palm oil from agroindustry liquid waste on the characteristics of the combustion process, performance, and emissions in a single-cylinder diesel engine. For the analysis of the combustion process, a diagnostic model was developed based on the cylinder pressure signal, which allows the calculation of the heat release rate, the accumulated heat rate, and the temperature in the combustion chamber. This is to assess the influence of these parameters on engine emissions. The experiments on the diesel engine were carried out using five types of fuel: conventional diesel, two biodiesel blends of residual palm oil (PB5 and PB10), and two biodiesel blends formed with palm oil and sunflower oil residues (PB5SB5 and PB10SB5). The engine was running in four different modes, which covered its entire operating area. Experimental results show that the in-cylinder pressure curves decrease as the percentage of biodiesel in the fuel increases. Similarly, the results showed a decrease in the heat release rate for biodiesel blends. The diagrams of the accumulated heat release curves were larger for fuels with higher biodiesel content. This effect is reflected in the thermal efficiency of biodiesel blends since the maximum thermal efficiencies were 29.4%, 30%, 30.6%, 31.2%, and 31.8% for PB10SB5, PB5SB5, PB10, PB5, and diesel, respectively. The emission analysis showed that the blends of biodiesel PB5SB5 and PB10SB allowed a greater reduction in the emissions of CO, CO2, HC, and opacity of smoke in all the modes of operation tested, in comparison with the blends of biodiesel PB5 and PB10. However, NOx emissions increased. In general, biodiesel with the percentage of residual sunflower oil does not cause a significant change in the combustion process and engine performance, when compared to biodiesel that includes only residual palm oil.

LEER
Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines
...
Hernández Comas, Brando | 2021-03-02

Internal combustion engines are widely implemented in several applications; however, they still face significant challenges due to the sealing capacity of the compression rings. Gas leakage through the crankcase, also known as blow-by, directly impacts power losses, overall efficiency, and global emissions. Therefore, the present study investigates the influence of parameters such as the ring gap, ring masses, and twist angle of the compression rings on the sealing capacity of the combustion chamber. A mathematical model is proposed to account for geometric, dynamic, and operational characteristics in a single-cylinder diesel engine. The results indicated that the greatest gas losses to the crankcase occur during the compression and combustion stages as a consequence of extreme pressure conditions. Specifically, at least 0.5% of the gases locked in the combustion chamber are released on each cycle, while increasing the mass of the compression rings boosts the gas leakage due to higher inertial forces in the rings. In contrast, a positive twist angle of the compression rings reduced the combustion gases leakage by 7.33 × 10−5 g/cycle. Additionally, a combined reduction in the gap of both compression rings minimized the leakage flows by 37%. In conclusion, the proposed model served as a robust tool to evaluate different parameters on the sealing capacity of the combustion chamber that contribute to minimizing global emissions. Secondary piston motion and ring distortion represent significant opportunities in future studies.

LEER
Study of the piston secondary movement on the tribological performance of a single cylinder low-displacement diesel engine
...
Duarte Forero, Jorge | 2020-10-30

The present study aims to analyze the secondary movement of the piston considering the deformations present in the piston skirt, the hydrodynamic lubrication, and the effects of the clearances in the connecting rod bearings. The analysis of the piston movement is performed by developing a mathematical model, which was used to evaluate the dynamic characteristics of the piston movement, the slap force on the piston skirt, the effect of the secondary piston movement on the connecting rod, and the influence of clearances in the connecting rod bearings and in the piston. For the study, the geometric of the crankshaft-connecting rod–piston system of a single-cylinder diesel engine is taken as a reference. The deformation model of the piston was carried out by means of a symmetric finite element model (FEM), which was integrated into the mathematical model of the piston. MATLAB® software (The MathWorks Inc., Natick, MA, USA) is used for the development of model simulations. The obtained results show that during the combustion cycle, there are six changes of direction in the secondary movement of the piston with lateral and angular velocities that can reach a magnitude of 0.13 m/s and 4 rad/s. The lateral and angular movement of the piston during its travel causes the appearance of impacts on the piston skirt with the cylinder liner, which produces an increase of approximately 500 N in the hydrodynamic forces in the connecting rod bearings. The force analysis shows that the range of the maximum magnitudes of these forces is between 1900 N and 3480 N. The increase in clearance between the cylinder liner and the piston skirt (Cpc) causes a greater lateral displacement and an increase in the angle of inclination of the piston. Analysis of the change in connecting rod bearing clearance shows that there are critical values in relation to clearance Cpc. The model presented allows us to analyze the different characteristics of the secondary movement of the piston, which involve the interaction between the piston skirt and the cylinder liner. Additionally, the influence of this movement on the connecting rod bearings is considered. The foregoing can be used as an analysis tool for the study of designs and/or modifications in the engine in such a way that greater durability of the components, reductions in acoustic emissions, and reduction in friction losses are achieved. View Full-Text

LEER

‹›

Repositorio Digital

Listar por tema "diesel engine"

Combustion and performance study of low-displacement compression ignition engines operating with Diesel–Biodiesel blends

Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines

Study of the piston secondary movement on the tribological performance of a single cylinder low-displacement diesel engine

Envíos recientes

Combustion and performance study of low-displacement compression ignition engines operating with Diesel–Biodiesel blends

Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines

Study of the piston secondary movement on the tribological performance of a single cylinder low-displacement diesel engine

Portales Institucionales

Enlaces de Interés

Contactos

Listar por tema "diesel engine"

Combustion and performance study of low-displacement compression ignition engines operating with Diesel–Biodiesel blends ﻿

Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines ﻿

Study of the piston secondary movement on the tribological performance of a single cylinder low-displacement diesel engine ﻿

Envíos recientes

Combustion and performance study of low-displacement compression ignition engines operating with Diesel–Biodiesel blends

Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines

Study of the piston secondary movement on the tribological performance of a single cylinder low-displacement diesel engine

Portales Institucionales

Combustion and performance study of low-displacement compression ignition engines operating with Diesel–Biodiesel blends

Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines

Study of the piston secondary movement on the tribological performance of a single cylinder low-displacement diesel engine