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Grupo de Investigación para el Desarrollo Socioeconómico - GIDSE

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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.

Numerical study of the physical processes of gas leakage in the compression ring in diesel engines

Pabón León, J A | 2021-09-03

In this research, the construction of a numerical model is proposed for the analysis of the friction processes and the thickness of the lubrication film present in the compression ring of internal combustion engines. The model is built using MATLAB software, and three load conditions are used as reference (2 Nm, 4 Nm, and 6 Nm) with a rotation speed of 3600 rpm, which correspond to a stationary single-cylinder diesel engine. Comparison between model estimates and experimental results show that the development model could predict the actual engine conditions. The deviation between the numerical model and the experimental data was 17%. It was shown that the increase in engine load causes a 16% increase in the friction force of the compression ring, which implies a 50% increase in power loss due to friction processes. In general, the model developed allows the analysis of the friction processes in the compression ring and its effect on the lubrication film, considering the leakage of the combustion gases. In this way, the construction of a more complex mathematical model is achieved, which allows improving the precision in the analyzes related to the interaction between the compression ring and the cylinder liner.

Study of the Kinematics and Dynamics of the Ring Pack of a Diesel Engine by Means of the Construction of CFD Model in Conjunction with Mathematical Models

Orozco Lozano, Wilman | 2021-11-28

The present research aims to analyze the kinematic and dynamic behavior of the piston ring package. The development of the research was carried out through the development of numerical simulation by means of CFD. The analysis involves the three piston rings for the development of simulations that are closer to the real conditions of the engine since most of the investigations tend to focus on the study of the compression ring only. The simulation was reinforced by the incorporation of mathematical models, which allow determining the piston kinematics, the lubrication properties as a function of temperature, contact friction, and gas leakage. For the simulation, the CAD of the piston and the connecting rod—crankshaft mechanism was carried out, taking as a reference the geometry of a diesel engine. From the results obtained, it was possible to show that the first ring exhibits considerably greater radial and axial movement compared to the second and third piston rings. Additionally, it was shown that the first and second rings tend to maintain a negative tilt angle throughout the combustion cycle, which facilitates the advancement of the combustion gases over the piston grooves. Therefore, it is necessary to use strategies so that these rings tend to maintain a positive inclination. The analysis of the pressure conditions in the second ring are 150% and 480% higher compared to the conditions present in the third ring. Due to the above, it is necessary to focus efforts on the design of the profile of this ring. The study of energy losses showed that the combination of leakage gases and friction are responsible for a mechanical loss between 6–16%. In general, the development of the proposed methodology is a novel tool for the joint analysis of the kinematic characteristics, pressure conditions, and energy losses. In this way, integrated analysis of changes caused by piston ring designs is possible.

Analysis of the influence of textured surfaces and lubrication conditions on the tribological performance between the compression ring and cylinder liner

Pardo García, Carlos Eduardo | 2021-05-06

The objective of the present investigation is to analyze the tribological performance between the union of the cylinder liner and the compression ring under the influence of surface texturing and different lubrication boundary conditions. The analysis is carried out by developing a numerical model, which involves hydrodynamic pressure, lubrication film thickness, textured surface, dynamic forces, and lubrication boundary conditions (starved lubrication and fully flooded lubrication). MATLAB® software (The MathWorks Inc., Natick, MA, USA) is used to solve the equations developed. The results show that the application of a textured surface on the cylinder liner allows obtaining a reduction of 20% and 5% in the asperity contact force and in the total friction force. Additionally, the textured surface allows for a 4% increase in MOFT. In this way, it is possible to reduce the power loss. The implementation of a boundary condition of fully flooded lubrication produces an overestimation in the total friction force due to the greater prominence of the lubrication film. Implementing a textured surface in the ring profile is an alternative way to reduce power loss. The results show that this alternative allows an 8% reduction in power loss.

Document details - A numerical model for the analysis of the bearings of a diesel engine subjected to conditions of wear and misalignment

Pardo García, Carlos Eduardo | 2021-04-09

In the present work, a numerical model is developed to investigate the influence of wear and misalignment on the bearings of a stationary diesel engine. The model implemented considers the effects of surface wear on the bearing, cavitation effects, and surface roughness. For the numerical analysis, changes in the surface roughness of σ = 0.75 µm, σ = 1 µm, and σ = 1.25 µm are defined, and changes in the bearing load of 50%, 75%, and 100%. The results demonstrated that increasing the surface roughness intensifies the bearing wear, which represents 18% and 140% of the bearing clearance for the roughness of σ = 1 µm and σ = 1.25 µm, respectively. Additionally, the surface roughness causes a considerable increase in the bearing wear rate. The results described a maximum wear rate of 20 µm/s. In general, increasing the bearing load by 25% doubles the hydrodynamic pressure conditions increases friction force by 33%, and reduces lubrication film thickness by 12%. The analysis of the angle of deflection, φx and φy, shows that the moment and the degree of misalignment tend to increase significantly with the increase in the magnitude of the angle φy. Negative angles of deflection, φx, produce a greater increase in the degree of misalignment and the moment. This implies a greater chance of contact with the bearing surface. In conclusion, the proposed methodology serves as a reliable tool to simultaneously evaluate key parameters on the tribological behavior of bearings that further extend their endurance and minimize wear damage.

Application of neural and bayesian networks in diesel engines under the flaw detection method

Prada Botia, Gaudy Carolina | 2021-05-22

The identification of premature faults in Internal Combustion Engines has become determinant to guarantee suitable operation. Therefore, this study focuses on the implementation of fault diagnostic methodology by using advanced algorithms such as Back Propagation neural networks and Bayesian networks. Results indicated that the proposed methodology serves as a robust tool to identify different fault conditions in a wide operational spectrum with an reliability of nearly 73%. Moreover, the Backpropagation network diagnostic methodology presented an reliability of 18%, which is 3% higher than Bayesian networks. Overall, the implemented methodology counterbalanced interference conditions and noise signals while providing versatility to operate for different types of engines. In conclusion, this study can be extrapolated to different fields of physics to assist in identifying flaws in experimental test benches.

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.

Simulation study of phase change materials operating in thermoelectric devices

Orjuela Abril, Martha Sofia | 2021-06-04

In this paper, a computerized analysis is performed to evaluate the effect of phase change materials on the performance of thermoelectric generators. This study was conducted using commercial OpenFOAM software. Analyze changes in temperature, potential and efficiency due to phase change materials. The study evaluated a variety of geometric and operational conditions, such as changes in material height and heat flux. The results obtained indicate that the presence of phase change material allows a significant increase in the temperature difference between the surfaces. The temperature difference is increased by 35% with a height of 3.25 mm. The temperature difference increases the potential of the thermoelectric generator and increases the maximum output voltage by 21%. Overall, phase change materials have been shown to improve thermoelectric efficiency by 23%. For test conditions, the maximum efficiency is 4.77%. From this result, it can be concluded that the phase change material is a promising alternative for improving the low efficiency of thermoelectric generators due to their heat storage capacity.

Development of a numerical methodology for evaluating physical properties and technical specifications in thermoelectric devices

Prada Botia, Gaudy Carolina | 2021-06-04

Typically, the performance evaluation of thermoelectric devices is done using experimental methods and analytical models, which require detailed information on the thermoelectric properties of the materials that make up the thermoelectric devices. However, this type of information is generally not available. Due to this situation, the present investigation seeks to develop a numerical methodology to determine the performance of thermoelectric devices, using technical reference specifications that are normally provided by the manufacturer, such as maximum current, maximum voltage, maximum temperature difference, and efficiency. The numerical model is made up of a series of equations based on thermoelectric phenomena, which generates a contribution in the area of physics. The results obtained are validated through experimental comparisons and the technical data of the thermoelectric devices. The comparison between the different results shows a maximum error of 5%. Therefore, the developed methodology is considered a robust tool for the realistic analysis of the performance of thermoelectric generators and thermoelectric coolers. The foregoing will allow massive use of this type of device in industrial applications and its commercial accessibility.

Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section

Rojas Suárez, J P | 2022-01-06

In the present investigation, an analysis of the fire resistance of the steel-reinforced concrete-filled steel tubular columns with circular cross-sections was carried out by means of numerical simulation. The development of the study was carried out by means of numerical simulation to predict the behavior of the column against fire. The results of the numerical model are validated by comparing the temperature levels obtained through experimental tests. From the results obtained, it is shown that the increase in the contact area between the steel and the concrete reduces the average temperature of the column, which implies a greater resistance to fire. The fire resistance of the columns with the steel profile designs are between 3.4 - 3.6 times higher compared to the column only made of concrete, which is an indication of the excellent performance of the steel-reinforced concrete-filled steel tubular columns with circular crosssections columns. In general, the methodology proposed in this research allows the analysis of the thermal physical phenomena of the different columns used for the construction of buildings.

Numerical and Experimental Analysis of the Potential Fuel Savings and Reduction in CO Emissions by Implementing Cylinder Bore Coating Materials Applied to Diesel Engines

Orjuela Abril, Martha Sofia | 2021-02-18

Currently, internal combustion engines contribute to the problem of global warming due to their need to use products derived from fossil resources. To mitigate the above problem, this study proposes the use of coatings on the cylinder bore in order to reduce fuel consumption and polluting emissions. Therefore, in the present study a numerical model is developed in which the tribological behavior, heat fluxes, and leakage of the combustion gases in the chamber are considered to evaluate the influence of the coating. Nickel nanocomposite (NNC) and diamond-like carbon (DLC) coatings are considered in the study. The results demonstrate that the NNC coating produces a 32% reduction in the total friction force of the compression ring. The estimated maximum temperatures for the lubricating oil were 214, 202, and 194 ◦C for the DLC, steel, and NNC materials. Increasing the temperature in the DLC coating can cause a reduction in the tribological performance of the lubricant. The estimates made show that the implementation of the NNC coating allows a maximum reduction of 5.28 ton of fuel and 39.30 kg of CO emissions, which are based on the global fleet of diesel engines forecast for the year 2025 (corresponding to one hundred and eighty million engines) and a test time of 1800 s. The proposed numerical model allows future analyses to be carried out for other types of materials used as coatings. Additionally, the model can be expanded and adapted to consider other systems that involve friction processes in the engine.

Thermodynamic study of a supercritical carbon dioxide Brayton cycle based on main compression intercooling configuration

Orjuela Abril, Martha Sofia | 2021-06-09

This study presents detailed thermodynamic modeling of a supercritical Brayton cycle operating with carbon dioxide as a working fluid for electric power generation. The study incorporates a main compression intercooling configuration while elucidating the effect of operational parameters on the overall performance based on energy and exergy perspectives. The model was carefully validated with relevant authors. Moreover, two different optimization methodologies, namely particle swarm optimization and fmincom, are evaluated based on convergence criteria. The results demonstrated that the fmincom reduced the iteration time between 140 s - 180 s. The cycle pressure played a central role in the stability of the thermophysical properties of the working fluid. The energy and exergy efficiencies present a direct relation with the inlet temperature. The air cooling and regenerators represent the biggest contributor to exergy destruction, whereas the compressors featured minimal impact on the exergy degeneration. Overall, the proposed configuration demonstrated robust performance to implement with high-grade heat sources, especially in non-interconnected areas.

Modeling and simulation of an improvement proposal through the method mechanized transplanting

Orjuela Abril, Martha Sofia | 2021-06-09

Rice agriculture in Colombia has high costs and low profitability, compared to rice agriculture in leading countries that are supported in different ways by their governments worldwide. Part of these high costs is due to the deficient technification of the processes, the absence of standardized procedures and the farmers' lack of resources. This article develops modeling and simulation of the implementation of the indirect seeding method by mechanized transplanting; these results are obtained through the study and definition of technologies for the cultivation method, the description of the process, machinery, equipment, and inputs, which determined the necessary capacity of the production plant through modeling and simulation in software Flexsim. Rice cultivation is one of the main incomes of countries with high population density and poor economy, alternatives and improvement actions are of great importance for the growth of the sector. As a result, there is evidence of improved crop productivity, better water consumption efficiencies by physical analysis (comparison of traditional and technician water consumption) and the necessary capacity of a production plant from harvesting to final packaging.

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.