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Gerencia y Escenarios Para El Desarrollo - GEDES

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Study of performance and emissions in diesel engines operating with biodiesel from soybean oil and water emulsions

Orjuela Abril, Martha Sofia | 2021-01-01

Este estudio evalúa la influencia en el proceso de combustión, consumo de combustible y emisiones contaminantes en un motor diesel, que opera con biodiesel a partir de aceite de soja y emulsiones de agua con porcentajes de 4% y 8%. Para este estudio, se utiliza un motor diesel estacionario que opera en cuatro condiciones de par diferentes y una velocidad de rotación fija de 3400 rpm. Los combustibles de prueba son diésel, biodiésel de aceite de soja y emulsiones de agua SB4W y SB8W. Los resultados indican que SB4W y SB8W provocan una reducción del 6% en el poder calorífico y un aumento del 18% y del 1% en la viscosidad y densidad. Sin embargo, la presencia de agua en el biodiésel puede ayudar a reducir el BSFC del motor en un 8%. El SB4W y SB8W permiten una reducción del 23% en las emisiones de NOx. Con el uso de combustible SB4W se obtiene una reducción del 16%, 29% y 14% en CO, HC y opacidad del humo en comparación con el biodiésel de aceite de soja. Se recomienda la inclusión máxima de 8% de agua en el biodiesel de aceite de soja ya que un porcentaje mayor puede provocar la presencia de combustiones incompletas.

Analysis of performance, emissions, and lubrication in a spark-ignition engine fueled with hydrogen gas mixtures

Pardo García, Carlos Eduardo | 2022-10-26

Hydrogen is one of the main alternative fuels with the greatest potential to replace fossil fuels due to its renewable and environmentally friendly nature. Due to this, the present investigation aims to evaluate the combustion characteristics, performance parameters, emissions, and variations in the characteristics of the lubricating oil. The investigation was conducted in a spark-ignition engine fueled by gasoline and hydrogen gas. Four engine load conditions (25%, 50%, 75%, and 100%) and three hydrogen gas mass concentration conditions (3%, 6%, and 9%) were defined for the study. The investigation results allowed to demonstrate that the injection of hydrogen gas in the gasoline engine causes an increase of 3.2% and 4.0% in the maximum values of combustion pressure and heat release rates. Additionally, hydrogen causes a 2.9% increase in engine BTE. Hydrogen’s more efficient combustion process allowed for reducing CO, HC, and smoke opacity emissions. However, hydrogen gas causes an additional increase of 14.5% and 30.4% in reducing the kinematic viscosity and the total base number of the lubricating oil. In addition, there was evidence of an increase in the concentration of wear debris, such as Fe and Cu, which implies higher rates of wear in the engine’s internal components.

Innovative Technology Strategies for the Sustainable Development of Self-Produced Energy in the Colombian Industry

Orjuela Abril, Martha Sofia | 2023-03-24

This research studies the current state of the Colombian industrial sector, which is focused on self-generation processes. The study’s objective is to search for viable technological strategies that strengthen this particular sector’s competitiveness and sustainable development. The analysis shows that internal combustion engines represent 49% of the technologies used for self-generation. The main fuel used in the sector is natural gas, with a percentage of 56%. The lack of strategies for the use of residual heat and technological inefficiencies caused a loss of 36% in the energy used in the Colombian industrial sector. Thermoelectric generators are a feasible way to recover energy from exhaust gases in engines used for self-generation. Additionally, they allow a 4% reduction in fuel consumption and an improvement in the engine’s energy efficiency. The use of hydrogen as fuel allows a 30% reduction in polluting emissions, such as CO2 , CO, HC, and particulate matter. Hydrogen production processes, such as water electrolysis, allow the participation of Colombia’s solar energy potential, leading to sustainable hydrogen production, efficiency (60–80%), and a lower economic cost. In general, the application of thermoelectric generators and the use of hydrogen gas allow the improvement of the Colombian industrial sector’s environmental, social, and economic aspects due to greater competitiveness and the reduction in emissions and operating costs.

Renewable Energies Resources Evaluation using a Geographic Information Systems in the Colombian Caribbean Region

Romero-Garcia , Gonzalo | 2021-08

This manuscript presents an integral evaluation of the use of wind and solar resources in the Colombian Caribbean region. For the use of solar and wind energy sources, spatial restrictions according to topography, natural parks, water reserves, indigenous and sacred reserves were taken into account. In addition, studies of the energy potential of wind and solar radiation were carried out through geostatistical analysis of different points in meteorological stations located in the region. Finally, areas with wind and solar potential were determined using the Geographic Information System for Renewable Energies (SIGER). The results show that the department of Guajira has the highest values of solar brightness (229-240 Month day), while the departments of Valledupar, Cesar, and part of Magdalena decrease in the range of 229 to 207 Month day. In terms of solar radiation, the departments of Guajira and Atlántico showed global solar radiation values of up to 6,015 W/m2. The departments of Cesar, Magdalena, and part of Bolivar showed values close to 5,259 W/m2; while Sucre, and Cordoba showed low solar radiation values of 4,502 W/m2. It is concluded that the departments of Atlántico and Guajira are excellent candidates for solar and wind energy projects due to their characteristics. The results of this manuscript are a fundamental basis for future technical-economic feasibility studies of renewable energy in the Colombian Caribbean region. In addition, it allows the elaboration of energy policies that encourage the execution of this type of study at a real level

Performance, Emission, and Economic Perspectives of a Diesel Engine Fueled with a Mixture of Hydroxy Gas and Biodiesel from Waste Palm Cooking Oil

Pardo García, Carlos Eduardo | 2021

This investigation experimentally examines the influence of hydroxy gas fumigation in a diesel engine fueled with a biodiesel blend derived from waste palm cooking oil (B10). For the experimental tests, a fixed rotation speed of 2000 rpm and a load condition of 50%, 75%, and 100% have been established. Hydroxy gas (HHO) has been added through the engine's air intake system at a flow of 0.5 lpm, 0.75 lpm, and 1 lpm. Results have demonstrated the positive effect of HHO fumigation on the combustion performance of the B10 blend. Moreover, a reduction of 4.3% in the BSFC and a 2.64% increase in peak pressure in B10 due to the presence of HHO have been observed. On the other hand, a decrease of 8.7%, 9.9%, and 22.8% in CO2, HC, and smoke opacity emissions has been evidenced with the addition of HHO in B10. B10 implementation has promoted NOx emission escalation. However, this increase has been only 1.23% compared to pure diesel. In conclusion, HHO enrichment favors combustion performance and emissions minimization, which represents a significant opportunity to mitigate the negative effect of the lower calorific power of these types of fuels.

Evaluation of Performance Parameters and Emissions of a Diesel Engine Fueled with Preheated Palm Oil Mill Effluent Biodiesel Blends

Pardo García, Carlos Eduardo | 2021

The current research analyzes the effect of fuel preheating on performance parameters and emission characteristics in a stationary diesel engine fuelled with palm oil mill effluent biodiesel blends. The investigation has been carried out on an experimental test bench under four-engine load conditions. The fuel injection temperature range is set between 35-75 °C. From the results obtained, it has been possible to demonstrate that the preheating process allows the reduction of fuel consumption and an increase in the efficiency of the engine powered with POME 5 and POME 10 blends. The preheating process has the potential to reduce by 14 % BSFC and increase by 17% the BTE of the engine. Additionally, the results have showed a reduction potential of 17.2%, 16.5%, and 15.6% in CO2, HC, and smoke opacity emissions when preheating processes are used in POME biodiesel blends. In general, this type of strategy is a promising solution to incentivize the use of biodiesel blends from palm oil mill effluent.

Evaluation of Energy Losses in Auxiliary Systems and Mechanisms Subject to Friction in a Stationary Diesel Engine

Pardo García, Carlos Eduardo | 2021

This research has developed a methodology to estimate energy losses associated with auxiliary systems and mechanisms subject to friction in a stationary diesel engine. The study methodology is based on mathematical models used to calculate engine friction forces and power losses. The analysis involves the cooling, the lubrication, the fuel injection system, and the engine's valve train, bearings, and piston mechanism. A stationary diesel engine with four load conditions and three rotational speed conditions has been taken as a reference for the study. The analysis of the results has showed that fuel injection is the auxiliary system with the highest energy consumption. In general, the cooling system, the lubrication, and the injection represent loss energy equivalent to 0.3%, 0.5%, and 0.9% of the chemical energy of the fuel. The interaction between the cylinder liner and the piston skirt is the main source of energy loss associated with friction processes. For valve train mechanisms, bearings and pistons it has been evidenced that these represent 1.25%, 1.91%, and 5.26% of the chemical energy of the fuel. In general, the methodology proposed in this research is a tool that allows diagnosing energy losses in auxiliary systems and engine mechanisms, which is useful for evaluating future strategies focused on energy improvement.

Analysis of the Tribological and Dynamic Characteristics of the Piston Compression Ring Under Different Engine Operating Conditions

Pardo García, Carlos Eduardo | 2021

In this investigation, a study of the tribological and dynamic characteristics present in the compression ring is executed for different engine conditions. A series of numerical simulations has been carried out using the OpenFOAM software for the study. The simulation conditions have been based on the parameters measured on a diesel engine test bench. Different ranges of rotation speed, load, and lubrication oil temperature have been established for the analysis. The results show that the parameters of rotation speed and engine load significantly influence the tribological and dynamic conditions of the piston compression ring. An increase of 425 rpm and 136 Nm in the rotational speed and load of the engine causes an increase of 13% and 34% in the power loss due to friction. The Top Dead Center and the Bottom Dead Center are the locations most prone to experience critical wear and tear. Increasing the lubricating oil temperature increases the maximum friction force by 9%. In general, the proposed methodology allows for establishing a direct relationship between the operating conditions and the tribological characteristics in the compression ring that directly affect the efficiency and useful life of the engine.

Study of the detonation wave in a rotating detonation combustor using hydrogen and mixtures ethylene-acetylene

Pardo García, Carlos Eduardo | 2021-04

In this study, a comparison between the use of hydrogen and a mixture of ethylene-hydrogen-acetylene as fuels is made in order to evaluate the characteristics of the detonation wave in a rotating detonation combustor. For the experimental development, an annular combustor, which has been connected to a supply of air, fuel, and hydrogen, has been used. The air and the type of fuel have been injected separately into the combustion chamber. The measurement of key parameters involves the use of ionization probes and pressure sensors, which have been located in the body of the combustion chamber. The results obtained indicate that hydrogen can reach an average pressure in the detonation wave 37% higher compared to the fuel mixture (ethylene-hydrogen-acetylene). For hydrogen, the equivalency ratio range is 38% higher compared to the fuel mixture. Therefore, the use of fuel mixtures is in a more limited operating range. The study of the detonation wave velocity indicates that the mixture of fuel and hydrogen can reach 68% and 93% of its ideal wave detonation velocity. However, in terms of height, both types of fuels reach a wave height of 30 mm. In general, hydrogen has characteristics that are more favourable in its detonation wave.

Study of the benefit of solar energy through the management of photovoltaic systems in Colombia

Orjuela Abril, Martha Sofia | 2021

One of the biggest problems in energy management is the impact on the environment. For this, it is necessary to propose new techniques and strategies which reduce pollution. Examples such as carbon dioxide and other greenhouse gas emissions promote an increase in the carbon footprint. This carries the search for resources from renewable sources as sunlight, wind, rain, waves, etc. From these sources, solar energy could be used in Colombia, especially the Atlantic Coast, due to high solar radiation in this region. This study is going to collect information about the advantages and disadvantages of using photovoltaic systems (PV systems) for solar energy management with a good cost-efficiency ratio. On the other hand, the development of solar energy will be studied and compared with other energy sources. In Colombia, there is a set of energy and regulatory policies around small self-generators with renewable energy sources, which can be natural or legal persons, that is, self-generators could be civilians, merchants, or small industries. Finally, it will be discussed about the energy plans as a proposal for improved energy management in the future.

Analysis of the characteristics of combustion, emissions, and energy efficiency of blends of heptanol with pure diesel fuel in compression ignition engine(Article)

García, C.P | 2021-09

The objective of this research is to study the influence of the heptanol content in conventional diesel fuel in different proportions for the evaluation of the combustion parameters, emissions, and energy efficiency. For the above, three heptanol blends identified as HP4%, HP8%, and HP16% have been used with a percentage of heptanol of 4%, 8%, and 16%, respectively. The tests have beencarried out on a single-cylinder stationary diesel engine at a constant load (9 Nm) and a rotational speed of 2800 rpm, 3200 rpm, and 3600 rpm. The results show that the percentage of heptanol causes an increase in the maximum values of the pressure in the combustion chamber and the heat release rate. In general, the presence of heptanol in conventional diesel produces an increase of 3.9% and 4.8% in the maximum values of these parameters. Additionally, the HP4%, HP8%, and HP16% heptanol blends allow reducing CO2, NOx, and smoke opacity emissions by 11.7%, 6.7%, and 37.1%, respectively. Due to the closeness of the physicochemical properties between the blends of heptanol and conventional diesel, a similarity between the energy and exergy performance between both fuels has been obtained. The above demonstrates the potential of heptanol to be used as a renewable fuel without the need for modifications to the engine. In addition, they have the ability to reduce NOx emissions, which is a problem in various types of biodiesel.

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.

Numerical simulation to analyze the physical behavior of centrifugal pumps as a turbine

Prada Botia, Gaudy Carolina | 2021-05

In this research, a methodology based on the development of numerical simulations is proposed to analyze the physical behavior of centrifugal pumps such as a turbine. Numerical simulations were carried out using OpenFOAM software. For the validation of the numerical model, the construction of an experimental test bench was carried out. The analysis carried out involves the evaluation of performance parameters of the pump as a turbine, such as head, power, and efficiency. Additionally, the effect of the rotation speed on the previous parameters is evaluated. From the results obtained, it was shown that the maximum relative error was 4%, 3.4%, and 3.8% for the head, power, and efficiency parameters, respectively. In general, it was evidenced that the proposed numerical simulation has the ability to describe the real trends of the pump as a turbine for different flow conditions. In addition, an 11% increase in rotational speed was shown to cause a 12%, 1.9%, and 3% increase in head, power, and maximum efficiency. The proposed methodology is considered an adequate tool to analyze performance and identify the best efficiency point of pump systems such as a turbine. In this way, greater energy use is guaranteed.

Study of the Cylinder Deactivation on Tribological Parameters and Emissions in an Internal Combustion Engine

Orjuela Abril, Martha Sofia | 2022-04-07

In the present investigation, a study is carried out using numerical simulation on the effects of cylinder deactivation on tribological parameters and emissions in an internal combustion engine. For the development of the research, a tribological model was used to predict the characteristics of the lubrication film, friction conditions, blow-by gas, and deformation of the piston rings. Additionally, the construction of a CFD model was carried out to describe the kinematic movement of the engine piston. The analysis of results allowed for the demonstration of the active cylinders presenting an increase of 21.53% and 7.65% in the pressure and temperature in the cylinder wall. Additionally, the active cylinders present a reduction of 11.33% in the minimum thickness of the lubrication film and an increase in the friction force due to asperities, which implies an increase of 33% in power losses due to friction. The implementation of technologies such as cylinder deactivation causes an increase in combustion gas leaks caused by the increase in pressure of the active cylinders. However, the use of this technology allows reducing 9.09%, 8.26%, and 7.41% in CO, HC, and NO emissions. Although the use of technologies such as cylinder deactivation allows significant fuel savings, it is necessary to consider the negative effects caused by this technology, such as the increase in combustion gas leaks and the increase in power loss by the greatest frictional forces.

CFD Analysis of the Effect of Dimples and Cylinder Liner Honing Groove on the Tribological Characteristics of a Low Displacement Engine

Orjuela Abril, Martha Sofia | 2022-04-07

The contact between the piston rings and the cylinder liner is an interface with a strong influence on the tribological behavior and, therefore, directly affects the useful life of the engine components and fuel consumption. Due to this importance, the present investigation carried out an analysis of the effects of dimples and the honing groove in the cylinder liner on the tribological characteristics. A tribological model was developed to study the friction forces, minimum film thickness, and friction coefficient for the present investigation. Similarly, a computational fluid dynamics model was built to determine the dynamic movement of the piston. The validation of the numerical model showed a close similarity with the real behavior of the engine, obtaining an average relative error of 14%. The analysis of the results showed that a 3% increase in dimples’ density leads to a 3.79% increase in the minimum lubricant film and a 2.76% decrease in friction force. Additionally, it was shown that doubling the radius and depth of the dimple produces an increase of 3.86% and 1.91% in the thickness of the lubrication film. The most suitable distribution of the dimples on the surface of the cylinder liner corresponds to a square array. In general, the application of dimples and honing grooves in the cylinder liner are promising alternatives to reduce energy losses and minimize wear of engine components.

Los negocios en la frontera entre Colombia y Venezuela del intercambio comercial a un conflicto social

Pabón León, Jhon Antuny | 2015-08-21

Border relations in the «living borders» have been an object of study due to the conditions under which the economy of the borders is developed. Investigations carried out between North Santander and Táchira State border are analyzed, comparing them with the principles of the German (the state-nation) and French (the border area) Schools. Studies of the Chamber of Commerce of Cúcuta are analyzed and discussed. It is concluded that the economy of North Santander is affected more by political and ideological positions than by international trade. Governments continue to ignore the reality of two peoples who share a border region, as it is exposed by the principles of the French School

Ergonomic assessment of the work place of the footwear assembly line. Case: city of Cúcuta - Colombia

Orjuela Abril, Martha Sofia | 2018-08-20

A quantitative diagnosis of the ergonomic valuation is presented for people who work as fitters in the footwear sector due to the use of chairs that are not related to the users' anthropometric measurements. To estimate the inconvenience, a population of 24 people working as fitters was taken, and a survey was carried out divided into three parts: analysis of the activity, ergonomics of the workplace and information on the chair, in which it was found that the dimensions of the chair are 21% below the recommended measurements, according to the anthropometric measurements of the user. Similarly, based on the General Shackel Comfort Scale, it was found that there is discomfort in the lower back, mid back, buttocks and neck mainly. Subsequently, a sample of 15 fitters with an average experience of 33.4 years was taken from a specialized company to carry out an osteomuscular valuation. It was found that the most representative conditions are carpal tunnel syndrome, musculoskeletal disorder, lowered shoulder and lordosis, with 80%, 73%, 60% and 60% of people affected, respectively, given the positions they adopt, the use of a non-ergonomic chair and repetitive movements that the work requires. It is concluded from the information collected, the perception of the users and the osteomuscular valuation that the seats used for the task are not adequate to the anthropometric dimensions of the fitters and generate effects on the health of the worker that impact on their comfort, quality of life and productivity.

Evaluación financiera ocasionada por la deserción estudiantil en la Universidad Libre Seccional Cúcuta

BERNAL CIFUENTES, OMAR OSWALDO | 2018-04-02

Objetivo. Por las necesidades financieras de la institución universitaria, así como por los requerimientos de las entidades gubernativas se define el objetivo de evaluar financieramente las incidencias de la deserción universitaria en la Universidad Libre Seccional Cúcuta, teniendo en cuenta que la información disponible en las organizaciones del mismo orden es incipiente, por efectos de la confidencialidad propia de cada ente. Método. La información y datos disponibles del tema en el campo financiero fueron pertinente unilateralmente; por tal razón se procedió a la modelización de algoritmos, que, apoyados con la ingeniería económica, recogen y procesan información financiera en función de valores razonables. El Método de desarrollo del estudio, inicia con el suministro de información de la deserción universitaria en los últimos cuatro años, clasificado por carrera universitaria, número de estudiantes en cada semestre o año lectivo según el caso, identificación cuantitativa de los estudiantes que por alguna razón no se matricularon, clasificación del excedente académico de no estudio que se calcula a valor presente, sopesado al valor de la matrícula del momento. Resultados. El resultado del proceso es un valor monetario que permite conocer que cantidad de recursos dejaron de ingresar a las arcas de la institución universitaria, que posteriormente se presupuestaría en estrategias, políticas y programas que contribuyan a disminuir la deserción y en consecuencia optimizar sus beneficios. Conclusión. El modelo se puede implementar en las diferentes instituciones educativas, con los debidos ajustes que se requieran. Se recomienda implementar el modelo desarrollado en esta investigación para períodos futuros, porque le permitiría tomar decisiones a la administración sobre las políticas y metas a proponer para reducir la deserción en la Universidad Libre Seccional Cúcuta.

Study of Furniture in Public Education in Relation to the User's Anthropometric Measurements. Case: UFPS Colombia

Orjuela Abril, Martha Sofia | 2018-10-15

A study is presented on the ergonomic criteria associated with the university chair and the anthropometric measurements of the users. For this purpose, a study was carried out with a simple random sample of 376 students from the University Francisco de Paula Santander, two instruments were designed to collect the information, a perception survey that would show the discomfort and difficulties generated by the furniture, and an anthropometric study of the seated position; In addition, the dimensions of a random specimen were taken to make a typological evaluation in contrast with the NTC 4734, according to the results it was demonstrated that 100% of those surveyed said they suffer at least one discomfort due to the posture and materials of the university chair, the most significant pain is present in the buttocks, the current chairs are 9.09% smaller than allowed by the norm and according to the anthropometric requirements, the dimensions of the university chair should increase in proportion 14.2%. It is concluded from the information collected that the university chairs do not meet the ergonomic requirements of comfort and functionality.

Computer technique for the suitability of digital evidence in attacking an information system: Forensic analysis for the digital custody chain

JACOME , NAYDU J | 2019-11-19

This article presents results of a research project that attempted to create a model of forensics in an information system; since forensic analysis allows to establish the causes of security commitment information system. The aim of the study was to determine the software tools to be used in the management of security incidents in an information system; required for the design of computer art for extracting digital evidence to anchor the chain of custody items. The research methodology was descriptive and applied document type, by analyzing the different tools technique that allows maintenance of digital evidence was designed, preserving the integrity of this as a test mechanism in a judicial process. In this way, the procedures to be performed to store information were established without being altered chain of custody solving the above questions: What is the chronological order in which the events of alteration, transmission or access occurred? What evidence have to believe you are a victim?, what are the damages incurred?, who do responsible for the incident?, what people are suspicious of the event?, who has investigated the incident and which actions has taken to preserve, identify, collect and analyze the data involved?; ensuring this way through technical steps and tools to be used for the preservation of the chain of custody, as an evidence in a court case.