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Klasični proces plinske turbine karakterizira kompresija zraka iz okoline, koji se u komorama izgaranja zagrijava izgaranjem goriva te tako stvoreni dimni plinovi ekspandiraju u turbini i proizvode mehanički rad. Performanse plinske turbine ovise o svemu što mijenja gustoću i/ili maseni protok zraka na usisu kompresora. Najočitije promjene u performansama plinske turbine su smanjenje snage i povećanje specifične potrošnje goriva s porastom temperature okoliša, pri čemu nastaju značajna odstupanja od vrijednosti garantiranih (i postignutih) pri ISO uvjetima. Hlađenjem zraka na usisu kompresora pri povišenim temperaturama okoliša postiže se povećanje masenog protoka i kompresijskog omjera, te se sprječava smanjenje snage i povećanje specifične potrošnje goriva. Primjenom plinskih turbina u kombikogeneracijskim postrojenjima za proizvodnju električne i toplinske energije, povećanje masenog protoka kroz plinsku turbinu dovodi do povećanja energije koju dimni plinovi odvode na ispuhu turbine, a koja se kod kombi postrojenja u kotlu utilizatoru predaje ciklusu parne turbine. Time je kod kombi postrojenja efekt smanjenja specifične potrošnje goriva još značajniji. U radu je na primjeru turbine GE-PG6101FA prikazana ovisnost o okolišnim klimatskim uvjetima, te način na koji se ta ovisnost može smanjiti ili otkloniti., The classical gas turbine process is characterised by air compression from its surroundings, heating fuel in the combustion chambers, hence causing the created flue gases to expand in the turbine and thus induce mechanical action. The performance of gas turbine depends on anything that affects the airflow density and/or mass at the compressor inlet. The most obvious changes in gas turbine performance is a reduction in power and an increase in specific fuel consumption following an increase in the ambient temperature, resulting in significant deviations of the guaranteed (and achieved) values at ISO conditions. In cooling air at the compressor inlet at increased ambient temperatures, an increase in the mass flow and compression ratio is achieved, thus preventing a reduction in power and an increase in specific fuel consumption. When using gas turbines in combined cycle cogeneration power plants for the production of electrical and thermal power, increasing mass flow through gas turbines leads to an increase in power transferred by the flue gases to the turbine exhaust, and which in the waste heat recovery boiler at the combined cycle plant transfers to the steam turbine cycle. Consequently, the effect at the combined cycle plant is a more significant reduction in specific fuel consumption. The work has used the example of the GE-PG610FA turbine to show the dependency on surrounding climatic conditions, and the manner in which this dependency can be reduced or removed.

The amount of heat transferred from the combustion chamber directly affects the combustion efficiency. Increasing the amount of heat transfer reduces the combustion efficiency. With thermal coating methods in engines, the amount of heat transfer is reduced and the combustion efficiency is increased. However, covering the entire combustion chamber with thermal material causes an increase in the knocking tendency and worsening of emission values in spark ignition engines. With the water injection method, emission values can be reduced significantly without worsening engine performance parameters. In the study, the upper surface of the piston was partially covered with MgOZrO2 ceramic material with high heat reserve in order to increase the engine efficiency. The coated engine was sprayed with water into the intake manifold at 10%, 20% and 30% by mass of instantaneous fuel consumption. By using the two methods at the same time, improvements in performance parameters and exhaust emissions have been achieved. In the TBL piston engine, power, torque, specific fuel consumption, effective efficiency and HC emissions improve, while NOx emissions increase. In the case of water injection into the intake manifold, the increased NOx emissions decrease without any deterioration in performance parameters. Improvements were found in engine torque and effective power by 4.1%, specific fuel consumption by 3.8% and effective efficiency by 3.9% at 20% water injection rate. Compared to standard engine data, a 20% reduction was achieved in NOx emissions at 30% water injection rate. In addition, reductions of up to 33% were detected in HC emissions at 20% water spraying rate. © 2023 Gazi Universitesi Muhendislik-Mimarlik. All rights reserved.

The purpose of the study is to evaluate the thermal performance of the gas turbine unit represented by (K3) under actual weather conditions by applying the first and second laws of thermodynamics, the design production of the unit (283.6 MW) at standard conditions (1 bar) and temperature (15) Celsius, which included the analysis of the unit energy and available energy. Hence, to find out the weaknesses and losses in the system ChemCad simulation has been used to estimate the effects of external factors (ambient temperature, compression ratio and relative humidity) for a whole year on the performance of the turbine unit. Overall results showed that the maximum exergy efficiency was obtained in November; it was ~37% when Ta was 19.39°C. The maximum efficiency obtained at Ta equal to 19.39°C, which was ~37.67%. Higher ambient temperature increases specific fuel consumption (SFC). The results show that the SFC for the practical and program calculations increases with the increase in the temperature of the external environment and reached the maximum rate in the practical calculations in September (0.224) at 33.27°C. Thus, it economically affects the price of power production. Moreover, the results showed that the combustion chamber occupied the first place for the destruction of available energy, and the results of energy efficiency and available energy were 39.20% and 30.83%, respectively.

Currently, many countries are promoting B100 as the main fuel for diesel engines towards the transition to 100% renewable energy applications. However, due to its properties, B100 has both advantages and disadvantages to replace diesel oil. Therefore, a bibliometric analysis was carried out to evaluate the performance and emissions of a diesel engine with the B100 being tested on a multi-cylinder diesel engine for cars. Unfortunately, only 12 of the 127 selected articles are eligible to be reviewed in detail and none of them discusses all the key performance of diesel engines which include Brake Thermal Efficiency (BTE), Specific Fuel Consumption (SFC), Cylinder Pressure (CPs), Heat Release Rate (HRR), NOx, and smoke. Through data synthesis, we found that the use of B100 provides advantages in engine noise, thermal efficiency, specific fuel consumption, and emissions under certain engine loads. On the other hand, it also has the potential to result in poorer performance, if there is no modification to engine components and the addition of additives. As a recommendation, the results of this analysis provide a guide for further research to examine the use of B100 with all diesel engine performance variables. Research paths can be developed with the wider potential to provide new arguments on various diesel engine technologies, engine capacities, B100 raw materials, and test environments.

The energy crisis and depleting fossil fuel resources have always been the focus of researchers. Fuel consumption of agricultural tractors is not an exception. Researchers have used different methods to predict fuel consumption. With the development of artificial intelligence in the last decade, all re-searchers’ attention has been directed towards it. Deep learning is a subset of machine learning, which was inspired by the data processing patterns in the human brain. The deep learning method has been used in research due to the advantages of high accuracy and generalization. So far, no research has used this method to predict fuel consumption. In this research, field experiments were carried out in sandy clay loam and clay soils to model the temporal fuel consumption and specific fuel consumption of an agricultural tractor using a convolutional neural network (CNN), while having some parameters such as the soil type, soil conditions, tool parameters, and operation pa-rameters. The experiments were conducted within each soil texture in a factorial manner based on the randomized complete block design (RCBD) with three replicates. For each soil texture, various moisture levels (8–17% for dry and 18–40% for moist soils), tractor forward speeds (1.2, 1.6, 1.8, and 2.2 km h−1), working depths (30 and 50 cm), the number of passes (2 and 6), and tire inflation pressure (20 and 25 psi) were selected, and cone index, dynamic load, and moisture content were measured in each experimental section. The designed networks used to predict the instant fuel consumption were of a CNN type. The results indicated that the network developed based on the Sgdm algorithm outperformed the others, and thus it was selected for modeling purposes. The network was evaluated based on R2 and MSE criteria. For the temporal fuel consumption, the best results were obtained while using 8-510-510-1 architecture with R2 = 0.9729 and MSE = 0.0049. The 8-100-95-1 architecture also led to the best prediction of the specific fuel consumption with R2 of 0.9737 and MSE of 0.0054. The high prediction accuracy and low error in this research compared to previous studies indicate the superiority of this method in order to predict fuel consumption. It was also observed from the results that the input parameters, which include soil, tool, and operational parameters, are all effective on fuel consumption. Proper management of some parameters, such as working depth, tire inflation pressure, and forward speed, can help to optimize fuel consumption.

One of the ways to improve the technology of limestone roasting in shaft furnaces is associated with improvement of conditions of combustion with natural gas when burning it directly in the layer. To implement this technology, it is necessary to ensure the development of two parallel processes: preparatory, in which the initial gas-air mixture is formed and heated to the ignition temperature, and the main one, during which a layer of combustion of gaseous fuel occurs. At air-blast tuyere feed and at coaxial jet supply of gaseous fuel under increased pressure when there are gas permeable nozzles in the path, a more powerful gas flow (natural gas) flows out of the nozzle at high speed into the external environment. It creates conditions for air flow ejection. Inside the annular space between the streams, a combustion zone is formed, on the inner and outer side of which there are circulating vortices directed along the axis of the jet to the nozzle. It improves stability of the gas-air mixture ignition. The considerable range of turbulent jets (at elevated pressures of the gaseous medium), as well as the possibility of sufficient complete mixing in the boundary layer, opens up the possibility of forming a gas-air mixture of a given composition along the front of the flare process, the movement of gas jets. To ignite the gas flow in the layer, it is necessary to ensure its preheating at least to a temperature of 800-1050 °C using a heat source located near its entrance. Energy efficiency of this direction is confirmed by experimental studies on a shaft furnace with a working space with diameter of 3 m. According to the results of experimental sounding of the heated zone of a limestone shaft furnace (in the mode of layer burning of natural gas), regularities were established in changing the temperature field of the burning layer with the formation of maximum temperature of 1200 °C at a distance of 200mm from the nozzle section. The depth of formation of the combustion zone was limited to the level of 110mm with the spread of the region of high temperatures over a distance of up to 1000 mm. Technological possibility of forming a region of high temperatures of 1100-1600 °C with a length of the high-temperature zone up to 2000mm was established. © 2020 National University of Science and Technology MISIS. All rights reserved.

The reduction in environment pollutant emissions is one of the main challenges regarding ground transportation. Internal combustion engines, used especially in hybrid propulsion systems, may be a solution in the transition to fully electric cars. Therefore, more efficient engines in terms of fuel consumption, emission generation and power density must be developed. This paper presents research regarding the architecture of the combustion chamber of an internal combustion engine with opposed pistons. The aim of this research was to find a combustion chamber architecture that would enable the engine to perform close to the program target of: NOx < 3.5 g/kWh, smoke (FSN) < 1, specific fuel consumption (bsfc) < 198 g/kWh. Three variants of the combustion chamber’s architecture have been studied. After the experimental research, the conclusion was that none of them fully reached the target; however, significant improvements have been achieved compared with the starting point. As a result, further research needs to be carried out in order to reach and even exceed the target.

The current development trend of global civil aviation is the growth of passenger and freight traffic, which entails the consumption of jet fuel. Under these conditions, increasing the efficiency of jet fuel used is of great importance. Global energy consumption is constantly growing, and, first of all, the question of diversification of oil resources arises, resources from which the bulk of motor fuels is produced. Other types of raw energy sources (natural gas, coal, bio-mass) currently account for only a small part. However, an analysis of the development of jet fuels indicates that work is underway to obtain these from other sources of raw materials, especially bio-fuels. Much attention is given to obtaining bio-fuels from renewable sources – such as algae. The issue of the mass transition of civil aviation to alternative fuels is complex and requires the solution of intricate technical as well as economic issues. One of these is the assessment of the impact of new fuels on GTE performance. It is important to give an objective and quick assessment of the use of various types of fuels on the main characteristics of the engine – i.e., throttle and high-speed characteristics. In this case, it is necessary to take into account chemical processes in the chemical composition of new types of fuel. To assess the effect of fuels on the characteristics of a gas turbine engine, it is proposed to use a mathematical model that would take into account the main characteristics of the fuel itself. Therefore, the work proposes a mathematical model for calculating the characteristics of a gas turbine engine taking into account changes in the properties of the fuel itself. A comparison is made of the percentage of a mixture of biofuels and JetA1 kerosene, as well as pure JetA1 and TC-1 kerosene. The calculations, according to the proposed model, are consistent with the obtained characteristics of a gas turbine engine in operation when using JetA1 and TC-1 kerosene. Especially valuable are the obtained characteristics of a gas turbine engine depending on a mixture of biofuel and kerosene. It was found that a mixture of biofuel and kerosene changes the physicochemical characteristics of fuel and affects the change in engine thrust and specific fuel consumption. It is shown that depending on the obtained physicochemical properties of a mixture of biofuel and kerosene, it is possible to increase the fuel efficiency and environmental friendliness of the gas turbine engines used.

One of the promising ways in environmentalizing marine internal combustion engines is the neutralization of harmful substances in exhaust gases through particular gas recirculation (EGR-technology). However, the use of such techniques conflicts with the engine's energy efficiency. In the work presented, the scheme-design solution of the exhaust gas recirculation system with using the heat of recirculation gases by an ejector refrigeration machine for cooling the air at the intake of ship's main engine is proposed. The effect of using the heat of recirculation gases for cooling the air at the intake of the engine is analyzed taking into account the changing climatic conditions for a particular vessel's route line. It is shown that the use of an ejector refrigeration machine reduces the air temperature at the entrance of the main engine by 5-15 ° С, which reduces the specific fuel consumption by 0.5-1.5 g/(kW∙h). This reduces emissions of harmful substances when the engine is running with recirculation of gases, in particular, NOx by 30-35%; SOx by 10-12%.

This paper describes the simulative approach to calibrate an already extremely highly turbocharged industrial diesel engine for higher low-speed torque. The engine, which is already operating at its cylinder-pressure maximum, is to achieve close to 30 bar effective mean pressure through suitable calibration between the compression ratio, piston-bowl shape and injection strategy. The basic idea of the study is to lower the compression ratio for even higher injection masses and boost pressures, with the resulting disadvantages in the area of emissions and fuel consumption being partially compensated for by optimizations in the areas of piston shape and injection strategy. The simulations primarily involve the use of the 3D CFD software Converge CFD for in-cylinder calibration and a fully predictive 1D full-engine model in GT Suite. The simulations are based on a two-stage turbocharged 1950 cc four-cylinder industrial diesel engine, which is used for validation of the initial simulation. With the maximum increase in fuel mass and boost pressure, the effective mean pressure could be increased up to 28 bar, while specific consumption increased only slightly. Depending on the geometry, NOx or CO and UHC emissions could be reduced.

В статье рассмотрен вариант установки треугольного гусеничного движителя на колёсный трактор класса 1.4 вместо ведущих колёс. Расчёты и испытания показали, что постановка треугольного гусеничного движителя позволяет существенно повысить сцепные свойства трактора класса 1.4., The article considers the option of installing a triangular caterpillar drive on a class 1.4 wheeled tractor instead of driving wheels. Calculations and tests have shown that the setting of a triangular caterpillar drive can significantly increase the adhesion properties of a tractor of class 1.4.

This study performed the performance and emission effects of adding Jet-A1 aviation fuel to diesel fuel in a direct injection, single-cylinder diesel engine. In addition, the response surface method was used to investigate combustion, performance, and emissions of the test fuel obtained by mixing Jet-A1 with diesel blends fuel under various engine conditions. Central Composite Design was used to create a design matrix. The input parameters were selected as brake torque and fuel type. On the other hand, the responses were selected as ignition delay time, specific fuel consumption, exhaust gas temperature, COVIMEP, CA50, CA10-90, CO, NOx, and soot emission. In order to determine the optimum operating range of the diesel engine, a desirability function was used. The optimum operating range of the diesel engine was found as brake torque of 11.25 Nm and Fuel Type of A25 by using the response surface method. Besides, response parameters were determined under optimum operating conditions as the specific fuel consumption of 0.257 kg/kWh, the ignition delay time of 1.296 ms, exhaust gas temperature of 367.53 °C, COVIMEP of 8.751%, CA50 of 14,984 °CA, CA10-90 of 95.319 °CA, CO of 264.06 ppm, soot emission of 0.715 (k factor (m-1)), and NOx of 132.279 ppm, respectively. © 2021 Elsevier Ltd

The increasing number of passenger cars worldwide and the consequent increasing rate of global oil consumption have raised the attention on fuel prices and have caused serious problems to the environment. Nowadays, the demand for reducing fuel consumption and pollutant emissions has paved the way to the development of more efficient power generation systems for the transportation sector. The lower fuel burning and pollutant emissions of hybrid electric vehicles give a strong motivation and encourage further investigations in this field. This research aims to investigate novel configurations, which could achieve further performance benefits for vehicle powertrain. Automakers claim that the employment of a gas turbine operating as range extender in a series hybrid configuration is the most efficiency solution in the coming years. In particular, a Micro Gas Turbine (MGT) can be considered as an alternative to the internal combustion engine (ICE) as a range extender for electric vehicles. The MGT produces less raw exhaust gaseous emissions such as HC and CO and static applications compared to the ICE. In addition, the MGT weight is lower than an equivalent ICE and potentially can reduce the level of CO2 especially in a vehicle application. This study presents a parametric study of MGT applications for Range-Extended Electric Vehicle (REEV). The main objective is to examine the MGT performance to meet the requirements for a REEV that could become competitive, in terms of fuel consumption and pollutant emissions, to equivalent diesel or gasoline hybrid propulsion units or to conventional diesel vehicle.

Determining the optimal structure of the tillage combine for working in a particular company is a very difficult task due to many factors. While searching for the optimal choice, it is necessary to strive for having fewer combines in operation, reduce the fuel costs and compensate damages due to changes in agrotechnical terms and soil compaction during the combines’ operation. In this article it is proposed to apply the Monte Carlo simulation for solving this issue. As a result of the analysis of models, it was observed that all combines can be divided into separate efficiency groups and form certain tillage complexes. After the analysis of these complexes, it was proposed to replace the tillage tools, which led to further reduction in total costs. So the transition to non-mouldboard technology in both high-efficiency and low-efficiency combines will lead to cost savings by 45%, and the introduction of new tools will reduce the fuel consumption by 61-64%. For high-efficiency machine complexes, non-mouldboard technology allows the reduction of the optimal number of aggregates by 25-32%. At the same time, the introduction of new tillage combines will reduce the number of operating combines by 50-58% due to reduced resistance and the combination of technological operations.

Introduction: Specific fuel consumption (SFC) for the boiler is the most important performance indicators of the work, both in the current and projected periods. The technical installation of metering stations of thermal energy from the boiler made it possible to evaluate the actual SFC over the period of interest with sufficient accuracy. However, the problem of controlling modes for operation of boiler units, which allows obtaining the minimum SFS remained unresolved. This paper presents the algorithm of finding the optimal group SFC for the boiler depending on the outside temperature. This approach is based on the linear programming method. Materials and Methods: The study of the group specific fuel consumption was carried out using the results of technological audit in Ruzaevka (Republic of Mordovia) in 2016–2017. For analysis we selected two district boiler with loads more 10 Gcal/hour. We used the general scientific methods and methods of linear programming. Results: To reveal the dependence of the effect of the order of operation of boiler units in their group SFC we developed an algorithm and a program. This problem can be solved by linear programming methods. The algorithm for finding the optimal group SFC represents a sequence of steps. The algorithm is implemented using a spreadsheet program in two boilers in Ruzaevka. We presented the calculated minimum, maximum and average SFC for the production of thermal energy from each of the boiler depending on the outdoor temperature. Discussion and Conclusions: One of the most effective and low-cost measures to reduce SFC for the heat energy from the boiler is to increase the accuracy of the compliance regimes of burning and strict compliance with the order of the boilers. The problem of determining the optimal order of operation of boiler units with a variety of individual SFC for the production of thermal energy from boilers is solved by linear programming. The findings of this study have a number of practical implications in the heating systems.

Stricter requirements for power in engines and difficulties in fueling gasoline engines at the airport make aircraft engine manufac-turers design new engines capable of combusting fuel derived from JET-A1. New materials used in compression-ignition engines enable weight reduction, whereas the technologies of a Common Rail system, supercharging and 2-stroke working cycle enable us to increasethe power generated by an engine of a given displacement. The paper discusses the parameters of about 40 types of aircraft compression ignition engines. The parameters of these engines are compared to the spark-ignition Rotax 912 and the turboprop. The paper also shows trends in developing aircraft compression-ignition engines.

The increase of the power density, improvement of fuel efficiency and minimization of the environmental impact of modern internal combustion engines form the main trend of the engine development. Turbocharging is pivotal to ensure the thermodynamical as well as commercial competitiveness of modern large diesel and gas engines. The optimization of the gas-dynamic and heat transfer characteristics of the gas flow in the intake system targeting the optimization of the gas exchange process is an important task in engine building. Numerical simulation of working process of the 8-cylinder 21/21 diesel-motor (Russia, Ekaterinburg) was performed with the ACTUS simulation software (Switzerland, Baden, ABB Turbo Systems Ltd). The numerical study showed that the geometric dimensions of the intake pipe significantly impact the flow dynamics. In particular, it is shown that the use of inlet pipe with a larger diameter (on the 8DM-21 engine) leads to the average 0.5% increase in the filling ratio. This leads to an up to 0.7 % increase in engine power and reduces the effective specific fuel consumption by about 0.50-0.75. © 2017 The Authors. Published by Elsevier Ltd.

Biodiesel attracts most of the researchers and automotive industries in recent years as an alternative fuel for diesel engines, because of its better lubricity property, higher cetane number, and less greenhouse gas emissions. The use of bio diesel leads to reduction in hydro carbons, carbon monoxide, and particulate matter, but increase in NOx emissions. Increase in biodiesel blends in standard diesel leads to increase in NOx emission. In this study, an attempt is made to reduce the NOx emis-sions of a diesel engine fueled with pure soy methyl ester (B100) with low pressure steam injection. Experiments were carried out and studied for both standard diesel and pure biodiesel of soy methyl ester with steam injection ratio of 5, 10, and 15% on mass ratio basis of air in the inlet manifold. The present study has shown that around 30% reduction in NOx can be achieved for the steam injection rate of 10% and considerable reduction for all other steam injection rates when compared to standard diesel and B100. It is also observed that steam injection having signifi-cant impact on reduction of other emissions such as HC, CO, and CO2. The study also noted marginal improvement in the engine brake power, brake thermal effi-ciency and reduction in specific fuel consumption at part loads and minor increase during peak load operation for the low pressure steam injection on B100.

Fuel catalytic additives have been tested for many years. Herein, their influence on the overall efficiency of combustion engines is investigated, and their pro-ecological impact is assessed. The majority of this research concerns diesel engines. Despite many advantages, to this day, the use of catalytic additives has not become widespread. Wishing to clarify the situation, a research group from the Wroclaw University of Science and Technology decided to investigate this matter, starting with verification tests. This article presents the methodology and results of testing an actual diesel engine, and evaluates the effects of the use of a fuel catalytic additive. The focus was on the analysis of fuel consumption and exhaust gas emissions from a Doosan MD196TI engine. The tested additive was a commercial fuel performance catalyst (FAMAX) with up to 5% ferric chloride as an organometallic compound. The proportion of the mixture with the fuel was 1:2000. These studies provide an energy and ecological assessment of propulsion in inland vehicles relative to current exhaust emission standards. The tests were carried out in accordance with the ISO 8178 standard, albeit on a much broader scale regarding engine operation than required by the standard. In this way, a set of previously published data was more than doubled in scope. Detailed conclusions indicate the positive effect of the tested fuel additive. The emission values decreased, on average by 16.7% for particulate matter (PM), 10.1% for carbon monoxide (CO), and 7.9% for total hydrocarbons (THC). Unfortunately, the amount of nitrogen oxides (NOx) increased by 1.2%. The average difference in specific fuel consumption (BSFC) between the fuel with additive and pure diesel fuel was 0.5%, i.e. below the level of measurement error. The authors formulated the following scientific relationship between the thermal efficiency of the engine and the operation of the catalyst: the effect of the catalyst on the combustion process decreases with the increase of the thermodynamic efficiency of the engine. This conclusion indicates that despite the proven positive effect of catalysts on the combustion process, they can only be used in markets where engines with low thermal efficiency are used, i.e., older generation engines.

Steam power plants have a considerable potential to meet the growing energy demand, but its dependence on conventional fossil fuels has hampered its viability. One of the ways to minimize fuel consumption and upgrade the performance of a Rankine cycle is by incorporating closed feedwater heaters(FWHs). The datasets contained in this paper are thermodynamic performance analysis carried out on reheat – regenerative steam power plant with FWHs using CyclePad V2.0 software. The thermodynamic performance indices assessed are thermal efficiency, network output, heat rate, fuel consumption, boiler efficiency and specific steam consumption. Result obtained show that an increase in the number of FWHs decreases the fuel consumption, heat rate, heat rejected in condenser and heat input to the cycle. This effect invariably can lead to a reduction in operating cost and environmental impacts.

Improving the exploitative and environmental performance of piston engines (PICE) is an urgent task for many engineers and scientists. The article presents the results of the upgrade of a gas-and-air system of a diesel PICE, carried out through changing the turbocharging system's configuration and modernizing the design of the admittance collector. The authors present a review of studies on the given subject and a description of the object of the research. The study was conducted on the basis of bench tests at a manufacturing plant and mathematical modeling using ACTUS program. The results of experimental studies on the main indicators of a basic and upgraded PICEs are presented. The gas exchange processes in the PICE under examination were studied in detail using mathematical modeling. For the given diesel PICE, improvement of the gas-and-air system leads to a growth in charging efficiency by 2.45-3.92%, a decrease in scavenging factor by 3.11-6.31% and a reduction of specific fuel consumption up to 3.33%. In the conclusion, new directions for increasing the efficiency of the given PICE are offered. © The Authors, published by EDP Sciences, 2020. Russian Science Foundation, RSF: 18-79-10003 The work has been supported by the Russian Science Foundation (grant No. 18-79-10003).

An evaluation was made to determine the effect of the glycerides presence resulting from the incomplete conversion of soybean biodiesel produced via alkaline catalysis and ethylic route on engine performance, and emissions in formulations containing 10 and 20% (m/m) of biodiesel used as additives in base diesel with low sulfur content and cetane ratings of 45 and 50. By way of comparison, similar formulations were used with soybean biodiesel methyl route with low concentration of glycerides. Tests on a diesel cycle engine with a mechanical fuel injection system indicated that the presence of glycerides decreases the volatility of biodiesel and increase the cetane number of fuels. The higher the cetane number, the higher the particulate matter emissions and the lower the unburned hydrocarbon emissions. Formulations with cetane number 50 showed higher emissions of particulate matter. The presence of glycerides in biodiesel reduces the fuel's vapor pressure, thereby increasing the cetane number and emissions of particulate matter and lower emissions of unburned hydrocarbons. The specific consumption of fuels formulated with biodiesel increases due to its lower enthalpy of combustion and to the presence of glycerides in fuels formulated with soybean biodiesel produced via the ethanol route.

The objective of this paper is to demonstrate possibilities how to reduce consumption of Diesel fuel on the one hand and to increase the performance of tractor aggregates on the other. Measurings were performed on a field with clayey-loamy soil, after the harvest of spring barley as forecrop and treatment of soil surface with disc harrowing. At the moment of measuring, the upper soil layer (till 10 cm) contained 16.5 % of humidity. Measured were the following parameters: consumption of Diesel fuel, engine revolutions, total time of ploughing, time of turning, depth of ploughing, and the swath of tractor aggregate. The specific consumption of diesel fuel Qm,1 and the efficiency (performance) of the aggregate W1 were calculated using the aforementioned parameters. The experimental tractor operated always with the full dose of fuel. Measurings were performed within zones A – economic revolutions of the engine (1 580–1 800 min−1) and B – maximum working revolutions of the engine (1 800–2 000 min−1). Basing on measured values it was found out that in zones A and B, the ploughing aggregate Case Magnum MX 285 plus a combined cultivator Köckerling Exaktgrubber – Vario showed 9.1 % of fuel saving. Values of efficiency increased by 11.5%. For the ploughing aggregate Case Magnum MX 285 plus the disc harrow Väderstad Excellent XT 620 the corresponding fuel saving was 17.2 %) while the value of efficiency increased by 7.2 %).

The object of this paper is to analyze the effect of setup of three point linkage on energetic and performance parameters of tractor aggregate. For this purpose were made two series of measurements. The first series was realized with the tractor NewHolland T7050 aggregate with 5-furrow reversible plough plough KUHN HUARD VM 150 5 NS. Data such as engine load, engine revolution, diesel fuel consumption, diesel fuel temperature, were got from CAN Bus network during the measurement. Then were measured following parameters total time of ploughing, dephth of ploughing, time of turning and swath of the tractor aggregate. The specific consumption of diesel fuel and the efficiency of the aggregate were calculated using the aforementioned parameters.The second series of measurements was realized with the tractor Zetor Proxima Plus 115 aggregate with four-furrow plough Kverneland 150 B. During the measurement the data such theoretical and actual speed of the tractor and force in the top link of three point hitch were recorded in the computer. Then were measured following parameters such as main time of ploughing, dephth of ploughing and swath of the tractor aggregate. By the first and second tractor aggregate were approved linear dependence of slip, performance and fuel consumption on the force in top link of three point linkage.

R ESU M O O estudo de fontes alternativas de energia ao oleo diesel mineral, como o biodiesel, com origem renovavel, e importante para o meio-ambiente e diversificacao da matriz energetica. Neste estudo foram levantados o consumo especifico de combustivel, o valor calorico do combustivel e a eficiencia do conjunto motor gerador da marca BRANCO em funcao de cargas resistivas, sob as seguintes proporcoes volumetricas entre o oleo diesel mineral com biodiesel: 0% (B0), 20% (B20), 40% (B40), 60% (B60) e 100% de biodiesel (B100). Para o ensaio utilizou-se motor de 7,36 kW, com gerador eletrico acoplado de 5,5 kW. As cargas utilizadas, 0,5 kW; 1,0 kW; 1,5 kW e 2,0 kW foram elevadas ate 5,0 kW, oriundas de um dinamometro de cargas resistentes. Assim, o desempenho do conjunto para cargas abaixo de 1,5 kW mostrou-se menor, pelo maior consumo especifico de combustivel (CEC), e reducao na eficiencia do conjunto motor gerador para a faixa de potencia. Para as proporcoes de biodiesel B40, B60 e B100 os resultados descreveram reducao no valor calorico e aumento do CEC. Portanto, realizando comparacao das proporcoes de biodiesel com o oleo diesel, a proporcao B20 substitui parcialmente o oleo diesel, sem perdas significativas do desempenho do motor gerador. Palavras-chave: consumo especifico de combustivel, valor calorico, eficiencia do conjunto motor gerador Engine-generator diesel cycle under five proportions of biodiesel and diesel A B ST R A C T The study of mineral diesel alternatives, such as biodiesel, a renewable fuel, is important for the environment and to diversify energy sources. This study evaluated an engine-generator BRANCO brand. Specific fuel consumption, calorific value and the overall efficiency as a function of the system load was measured, using diesel oil and biodiesel blends. The biodiesel proportions in the composition were 0% (B0), 20% (B20), 40% (B40), 60% (B60), and 100% (B100). The engine that was used during the test has a power of 7.36 kW, and the electric generator was 5.5 kW. The group was submitted to resistive loading, in the range: 0.5 kW, 1.0 kW, 1.5 kW; growing up to 5.0 kW. The results have shown that, when operating at lower loads (less than 1.5 kW), the engine-generator performance decreased, while the specific consumption increased, leading to an efficiency reduction. The biodiesel proportions B40, B60 and B100 described reduction in caloric value and increased the specific fuel consumption. Therefore, comparing the proportions of biodiesel with diesel oil, the proportion B20 replaced diesel oil without significant losses in engine-generator performance.

Ambient conditions have significant effect on combined cycle power plants (CCPPs). Parameters-like efficiencies, fuel consumption, power production and even operation cost differ according to the ambient conditions that depend on the climate that cannot be changed. Therefore, deciding the location of the plant wisely would bring more efficient and profitable. In this paper, exergy analysis based on the second law of thermodynamics, considering environmental temperature variations, are performed for a cogeneration power plant. Mathematical model of analyse is introduced. Magnitudes of the variation of irreversibility, reversible power, power production and specific fuel consumption (SFC) are evaluated for the combined cycle. The results indicated that, decrease of environmental temperature augments the energy performance of the combined cycle form about 53% to 56% and improves the exergetic performance from about 51% to 56%. However, the augmentation via temperature decrease is not continuous. It is shown that the environmental temperature decrease causes a reduction about 5% in the SFC.

Bu tez çalışmasında, bir dizel motorun piston çanak geometrisi özgül yakıt tüketimi açısından Hesaplamalı Akışkanlar Dinamiği (HAD) kullanılarak optimize edilmiştir. Bir boyutlu gaz değişim analizi yardımıyla motor performans karakteristiği incelenmiştir. AVL Boost programı, bir boyutlu gaz değişim analizi ve motor performans karakteristiklerini belirlemek için kullanılmıştır. HAD analizlerinde öncelikle hava akış karakteristiği incelenmiştir. İki emme portuna sahip motorun döngü analizleri çalışılmıştır. Ticari HAD programı STAR-CD döngü analizleri için kullanılmıştır. Öncelikle, döngü analizleri kötü, orta ve iyi ağ yapılarında çalışılmıştır. Orta ve iyi ağ sonuçları birbirine oldukça yakın çıktığından, geri kalan HAD simülasyonları orta ağ yapısında gerçekleştirilmiştir. Türbülans modelinin döngü sayısı üzerindeki etkilerini görmek için Standard k-e, Realizable k-e ve RNG k-e türbülans modelleri kullanılmıştır. Motor valf hareketleri ve silindir bölgesindeki pistonun yukarı ve aşağı hareketi sonucu hücrelerin, katmanların eklendiği ve silindiği piston olayları için STAR-CD alt modülü olan ES-ICE programı kullanılmıştır. Reaktif Hesaplamalı Akışkanlar Dinamiği (RHAD) simülasyonları, periyodik sınır koşulu kullanan ve bir yakıt enjektör deliğine karşılık gelen 45 derecelik sektör geometrisinde gerçekleşmiştir. Hesaplamalar, emme ve egzoz valfleri kapalı olduğu 600-800° krank açıları (KA) arasında 200° KA süresince gerçekleştirilmiştir. ECFM-3Z, Extenden Coherent Flame Model -3 Zone, yanma modeli olarak kullanılmıştır. Sıvı Dizel yakıtın iki fazlı modeli için Lagrangian yaklaşımı kullanılmıştır. Sprey oluşum ve atomizasyonunu simüle etmek için Bag Break-Up ve Stripping Break-Up modellerinin oluşturduğu Reitz ve Diwakar ayrışma modeli kullanılmıştır. Uzaysal ve zamansal ayrıştırma ve türbülans modelleme etkileri dikkatle incelenmiştir. Sonuçların doğruluğu, HAD tahminleri ile ölçüm verileri silindir içi basınç ve açığa çıkan ısı yayılımı karşılaştırılarak gösterilmiştir. 0.1° krank açısına karşılık gelen zaman adımı ile orta hesaplama ağ yapısını kullanan reaktif HAD tahminleri, ölçülen verilere kıyasla %2.3'lik bir tutarsızlık göstermektedir. Tahminlerin doğruluğu gösterildikten sonra, optimizasyon çalışması için piston çanak geometri parametreleri belirlenmiştir. Seçilen 9 parametre HEEDs programının SHERPA algoritması kullanılarak, Özgül Yakıt Tüketimini (ÖYT) göre optimize edilmiştir. 92 farklı geometrinin analizi sonucunda güç açısından %5.8, özgül yakıt tüketimi açısından %5.5 oranında iyileşme sağlanmıştır. Fakat optimize edilmiş yeni piston çanak geometrisinin mevcut tasarıma göre NOx emisyonunda %15 artışa sebep olduğu gözlemlenmiştir., In this thesis, the piston of a Diesel engine has been optimized using Computational Fluid Dynamics (CFD) with respect to Specific Fuel Consumption. With the help of one-dimensional gas exchange analysis, the engine performance characteristic was examined. The AVL BOOST program was used for one dimensional gas exchange analysis and to identify the engine performance characteristics. Swirl analysis of the engine with double suction manifold was studied. The commercial CFD software STAR-CD was used for engine swirl investigations. First, a detailed coarse, medium and fine mesh study were carried out for the swirl computations. It was observed that the results of fine and medium mesh were quite similar such that the rest of the CFD simulations could be carried out on the medium computational mesh. Standard k-e, Realizable k-e and RNG k-e turbulence models were used to see the effects of turbulence modelling on the engine swirl number. A sub module of STAR-CD, ES- ICE is used for the engine moving valve and piston events where cell-layer addition and deletion is employed in the cylinder domain while piston moves down and up respectively. Reacting Computational Fluid Dynamics (RCFD) simulations have been vii performed for a 45 degree sector geometry that corresponds to one fuel injector hole making use of the periodicity boundary condition. Computations are carried out for the duration of 200° crank angle (CA) between 600° – 800° CA while the intake and exhaust valves are closed. ECFM-3Z, Extended Coherent Flame Model - 3 Zone is used as combustion model. A lagrangian approach is used for two phase modelling of the liquid Diesel fuel. Reitz and Diwakar primary break-up modelling coupled with either Bag Break-Up or Stripping Break-Up modelling are used to simulate the spray formation and atomization. Spatial and temporal discretization and turbulence modelling effects have been carefully studied. The CFD predictions of the in-cylinder pressure and Apparent Heat Release are compared with the measurement data to validate the fidelity of the results. The reactive CFD predictions using the medium computational mesh with the temporal time step that corresponds to 0.1° Crank Angle shows a discrepancy of 2.3% compared to the measured data. After the validation of the predictions the geometrical parameters of the piston bowl were determined for optimization study. The SHERPA algorithm of the HEEDs program was used to optimize the chosen 9 geometrical parameters with respect to Specific Fuel Consumption (SFC). As a result of the analysis of 92 different geometries, an improvement of 5.8% in terms of power and 5.5% in terms of specific fuel consumption was achieved. However, there was one penalty of the optimized geometry in terms of NOx emission that the optimized newly designed piston bowl geometry yields a 15% increase in NOx emissions compared to the current baseline geometry.