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Low-rigidity thin-walled parts are components of many machines and devices, including high precision electric micro-machines used in control and tracking systems. Unfortunately, traditional machining methods used for machining such types of parts cause a significant reduction in efficiency and in many cases do not allow obtaining the required accuracy parameters. Moreover, they also fail to meet modern automation requirements and are uneconomical and inefficient. Therefore, the aim of provided studies was to investigate the dependency of cutting forces on cutting parameters and flank wear, as well as changes in cutting forces induced by changes in heating current density and machining parameters during the turning of thin-walled parts. The tests were carried out on a specially designed and constructed turning test stand for measuring cutting forces and temperature at specific cutting speed, feed rate, and depth of cut values. As part of the experiments, the effect of cutting parameters and flank wear on cutting forces, and the effect of heating current density and turning parameters on changes in cutting forces were analyzed. Moreover, the effect of cutting parameters (depth of cut, feed rate, and cutting speed) on temperature has been determined. Additionally, a system for controlling electro-contact heating and investigated the relationship between changes in cutting forces and machining time in the operations of turning micro-machine casings with and without the use of the control system was developed. The obtained results show that the application of an electro-contact heating control system allows to machine conical parts and semi-finished products at lower cutting forces and it leads to an increase in the deformation of the thin-walled casings caused by runout of the workpiece.

The specific character of the process of machining of axisymmetric low-rigidity parts makes it difficult to obtain finished products with a required accuracy of shape and dimensions and surface quality. The methods traditionally used to achieve accuracy in the machining of low-rigidity shafts considerably reduce the efficiency of the process, fail to meet modern automation requirements, and are uneconomical and not very productive, which means new methods for controlling the machining of low-rigidity shafts need to be looked for. This article presents a structural and a calculation scheme of a machining system for the turning of low-rigidity parts and a control model based on the second-order Lagrange equation. The first section of this paper presents qualitative relationships among variables in the proposed technological system for machining axisymmetric low-rigidity parts. Moreover, schematic of the machining system for the processing of such parts as well as equations describing the energy state of the machining system is presented. Next, mathematical model of optimal system control during the machining process, which permits to control a system under specific conditions and obtains a higher shape accuracy were introduced. The key stage of the verification process concerns the numerical validation of proposed solutions. Experimental studies confirm that the utilization of the proposed mathematical models describe the properties of the original object with sufficient accuracy and allow to obtain a higher machined shaft shape accuracy.

The creep trend method is used for the analysis of the development of electric car production in three regions: The United States, the European Union and Japan. Based on vehicle registration and population growth data for each year the creep trend method using historical data for the years 2007–2017 is applied for forecasting development up to 2030. Moreover, the original method for calculating the primary energy factor (PEF) was applied to the analysis of power engineering systems in the regions investigated. The assessment of the effects of electromobility development on air quality has been performed, reduction values for pollutant and greenhouse gas emissions have been determined, which was the main objective of this manuscript. Mitigation of air pollutant emissions, i.e., carbon dioxide (CO2), carbon monoxide (CO) and nitrogen oxides (NOx) was estimated and compared to the eventual expected increase of emissions from power plants due to an increase of the demand for electricity. It can be concluded that electricity powered cars along with appropriate choices of energetic resources as well as electricity distribution management will play the important role to achieve the sustainable energy economy. Based on the emission reduction projections resulting from the projected increase in the number of electric cars, (corrected) emissions will be avoided in 2030 in the amount of over 14,908,000 thousand tonnes CO2 in European Union, 3,786,000 thousand tonnes CO2 in United States and 111,683 thousand tonnes CO2 in Japan.

Improvement of the energy efficiency of public buildings appears to be one of the best ways to simultaneously reduce energy consumption as well as the negative impacts on the environment. The work is dedicated to the analysis of modernization process of the energy system in a sports facility in a way leading to design of smart energy system. The proposed solution, being a specific case study, offers optimal use of energy in the facility, significantly reducing the demand for energy derived from fossil fuels (heat providers and conventional power plants). The project, on its first step, consists of recovering energy from sewage that usually is irretrievably lost. This option allows to achieve the assumed goals simultaneously optimizing the investment costs. The proposed solution mitigates air pollution and harmful gas and dust emissions to the atmosphere, and contributes to an increase of both the attractiveness and competitiveness of the area in which the sports facility is located. The next step will be further automation of the system and intelligent synchronization of time-dependencies of the processes.

The efficiency of a gas turbine can be affected by the use of different biofuels usually with a relatively Lower Heating Value (LHV). The paper evaluates the impact of calorific value of fuel on turbine performance and analyzes the possibilities of optimizing turbine construction from the point of view of maximum efficiency for a particular fuel. The several variants of design of small power microturbines dedicated to various biofuels are analyzed. The calculations were carried out for: gas from biomass gasification (LHV = 4.4 MJ/kg), biogas (LHV = 17.5 MJ/kg) and methane (LHV = 50 MJ/kg). It is demonstrated that analyzed solution enables construction of several kW power microturbines that might be used on a local scale. Careful design of such devices allows for achieving high efficiency with appropriate choice of the turbine construction for specific fuel locally available. Such individually created generation systems might be applied in distributed generation systems assuring environmental profits.

The article analyzes the dynamics of the development of the electromobility sector in Poland in the context of the European Union and due to the economic situation and development of the electromobility sector in the contexts of Switzerland and Norway. On the basis of obtained data, a forecast was made which foresees the most likely outlook of the electric car market in the coming years. The forecast was made using the creeping trend method, and extended up to 2030. As part of the analysis of the effect of the impact of electromobility, an original method was proposed for calculating the primary energy factor (PEF) primary energy ratio in the European Union and in its individual countries, which illustrates the conversion efficiency of primary energy into electricity and the overall efficiency of the power system. The original method was also verified, referring to the methods proposed by the Fraunhofer-Institut. On the basis of all previous actions and analyses, an assessment was made of the impact of the development of the electromobility sector on air quality in the countries studied. Carbon dioxide tank-to-wheels emission reductions which result from the conversion of the car fleet from conventional vehicles to electric motors were then calculated. In addition to reducing carbon dioxide emissions, other pollutant emissions were also calculated, such as carbon monoxide (CO), nitrogen oxides (NOx) and particulate matter (PM). The increase in the demand for electricity resulting from the needs of electric vehicles was also estimated. On this basis, and also on the basis of previously calculated primary energy coefficients, the emission reduction values have been adjusted for additional emissions resulting from the generation of electricity in power plants.

Nowadays more and more emphasis is placed on the protection of the natural environment. Scientists notice that global warming is associated with an increase of carbon dioxide emissions, which results inter alia from the combustion of gasoline, oil, and coal. To reduce the problem of pollution from transport, the EU is introducing increasingly stringent emission standards which should correspond to sustainable conditions of the environment during the operation of motor vehicles. The emissivity value of substances, such as nitrogen oxides (NOx), hydrocarbons (HC), carbon monoxide (CO), as well as solid particles, was determined. The aim of this paper was to examine, by means of simulation in the Scilab program, the exhaust emissions generated by the 1.3 MultiJet Fiat Panda diesel engine, and in particular, carbon monoxide and nitrogen oxides (verified on the basis of laboratory tests). The Fiat Panda passenger car was selected for the test. The fuels supplied to the tested engine were diesel and FAME (fatty acid methyl esters). The Scilab program, which simulated the diesel engine operation, was the tool for analyzing the exhaust toxicity test. The combustion of biodiesel does not necessarily mean a smaller amount of exhaust emissions, as could be concluded on the basis of information contained in the subject literature. The obtained results were compared with the currently valid EURO-6 standard, for which the limit value for CO is 0.5 g/km, and for NOx &minus, 0.08 g/km, and it can be seen that the emission of carbon monoxide did not exceed the standards in any case examined. Unfortunately, when analyzing the total emissions of nitrogen oxides, the situation was completely the opposite and the emissions were exceeded by 20&ndash, 30%.

Intensified action aimed at reducing CO2 emissions and striving for energy self-sufficiency of both business entities and individual consumers are forcing the sustainable development of environmentally friendly and renewable energy sources. The development of an appropriate class of equipment and production technology is not without significance in this process. On the basis of a proven design for a combustion burner for ecological fuels, a new biofuel burner, also dedicated to prosumers’ energetics, was built. The aim of the study was to determine the effect of the type of biofuel on a burner’s output parameters, especially gaseous emissions, during the combustion of four types of fuels, including three types of biomass. The combustion temperature was measured for lignite, wood pellets, straw pellets, and sunflower pellets. An analysis of exhaust gas composition was performed for lignite and wood pellets. The results of exhaust emissions and combustion temperatures were compared with the burners currently in use. The use of a new burner might contribute to cleaner combustion and reducing the emissions of some gaseous components.

Biowastes from the food industry can be applied as a usable material after appropriate treatment (i.e., agglomeration). Biowastes are materials that could have better properties if they are mixed. Brewery and oilseed wastes were compressed and evaluated by their quality and microstructure. This article presents the influence of food wastes&rsquo, type on their biodegradable composite properties. Rapeseed cake and brewer&rsquo, s threshing were used separately and mixed in three different proportions: 30:70, 50:50, 70:30. The data were obtained by mechanical testing on the Instron machine with different pressure forces of 30,000 N and 50,000 N. Strength and elasticity parameters, expansion after the test and in 24 h were estimated. The characteristics such as density, relaxation and compaction after the agglomeration process of biomass allows the selection of the best material and method for optimal composite quality. The results show an upward trend in composite density with decreasing content of brewery waste in a sample. Rapeseed cake can be considered as the material more susceptible to the compaction process. In addition to material properties and its lower density, the reason may be due to the granulometric composition of particles, density and particle size which was confirmed by SEM structure observations. Images of composites were analyzed on the basis of morphological plant tissue structures.

The paper aims to evaluate the energy efficiency of a plantation as a function of amounts of energy required by the agricultural production processes. Computations were based on derived mathematical formulas, and the elaborated algorithm was implemented as a macro in an EXCEL spreadsheet. Obtained results applied to rapeseed plantations at various conditions concerning the structure of a plantation and applied agricultural operations. On the basis of the results, the EROEI type of indicators is strongly dependent on the choice of production technology, as well as on several aspects of workflow organisation.

The effect of embodied energy on energetic effectiveness of biodiesel production is studied. Embodied energy, i.e. energy consumed for production of a technical device, is gradually consumed during the life time of that device. The amount of embodied energy consumed during individual agricultural operation affects the energetic effectiveness of that operation, as well as that for the whole production process. The embodied energy in agriculture is associated with the use of machinery , transportation means, fertilizes, etc. The paper estimates the effect of embodied energy in the rapeseed biodiesel production basing on computer modelling.

An analysis was carried out for different thermodynamic cycles of power plants with air turbines. Variants with regeneration and different cogeneration systems were considered. In the paper, we propose a new modification of a gas turbine cycle with the combustion chamber at the turbine outlet. A special air by-pass system of the combustor was applied and, in this way, the efficiency of the turbine cycle was increased by a few points. The proposed cycle equipped with a regenerator can provide higher efficiency than a classical gas turbine cycle with a regenerator. The best arrangements of combined air–steam cycles achieved very high values for overall cycle efficiency—that is, higher than 60%. An increase in efficiency to such degree would decrease fuel consumption, contribute to the mitigation of carbon dioxide emissions, and strengthen the sustainability of the region served by the power plant. This increase in efficiency might also contribute to the economic resilience of the area.

Rapeseed plantation biodiesel production systems require the transportation of goods, like raw materials, machines and tools, and products between various conversion stages of agricultural as well as industrial subsystems. Each transportation step requires the consumption of some energy. This consumption decreases the net amount of energy delivered out of the biofuel production system, and consequently decreases the energetic efficiency of the system. The majority of studies on biofuel sustainability are done by means of the LCA method with the use of a data average for some region and period of time. Such analyses do not reveal the possible causes of the conclusions determined. The present work deals with computer modelling of the influence of the energy consumed on those transport routes on the energetic efficiency of the production system. The model enables determination of the effects caused by changes introduced to technological parameters. The effects caused by variation of fuel consumption, the load capacity of transportation means, size of plantation, distribution and sizes of individual fields, distances between fields, plantation yield, and finally the distance between the plantation and the industrial facility are studied using the numerical model developed earlier. This approach is aimed towards identifying the reasons for the behavior of a system controlled by many somewhat coupled variables.

A number of technologies of biofuel production from various biomass crops are already in use, and many studies on new ones are carried out. Biomass production, like any other production processes, involves a number of necessary processes that facilitate subsequent production steps. Those subsidiary processes (e.g. tillage or logistic operations) are connected with consumption of energy. It is therefore important to assure that the sum of energy inputs into those technological steps does not exceed the energy output from the system. Obviously, large energy gain is desired. The paper is devoted to the estimation of energy inputs made into the subsidiary processes occurring in the agricultural subsystems in which various topological structures of plantations as well as for various technologies of tillage, and different requirements for transportation are allowed. Mathematical model describing above mentioned dependencies is derived, and appropriate algorithm elaborated for numerical computations, that have been performed for rapeseed plantations. The results demonstrate evident effects of the choices of technology, and organization of work onto efficiency of plantation as measured by EROEI - type indicator.

The depletion of conventional energy sources, including crude oil, is one of the cause of the search for alternative carriers and fuels in order to prevent an energy crisis. Due to the progressing climate change, each new solution must comply with the principles of sustainable development. Dynamic development in the transport sector and, as a consequence, the increase in the number of vehicles on the roads negatively affect the atmosphere and the environment, which is why the share of biofuels, which are used to minimize this negative impact, is steadily increasing. This paper analyzes the emissivity (emission capability) of biofuels such as fatty acid methyl esters (FAME), ethanol, dimethyl ether and butanol and compares them with conventional fuels. A computer simulation was used, based on the real parameters of vehicles and fuels. The test procedure was carried out in accordance with the appropriate New European Driving Cycle (NEDC) approval test for such cars. In addition, a life cycle assessment (LCA) for the fuels and vehicles in question was carried out using the SimaPro package. Based on the results obtained from the z computer simulation, it was found that diesel fuel showed lower emissivity than petrol and its alternatives. However, FAME fuel provided more carbon dioxide than conventional diesel. As far as petrol is concerned, it was less emissive than dimethyl ether. Ethanol and butanol reduced emissions by 7% and 15%, respectively. After taking into account CO2 emissions generated in the production process, both FAME and butanol were not very favorable in the context of other fuels. The results might be used for appropriate fuel use management.

The need for finding the replacement for fossil fuels causes several technical and technological problems in the engine construction as well as the fuel production and its standardisation. This particularly concerns biofuels. The variety of biological resources and possible conversion routes leads to the multiplication of fuel properties. The regional dependence of biomass resources might cause interregional incompatibility of fuels, which should be avoided. Our previous studies have shown that computer modelling is capable of providing information on the dependence of engine performance upon the type of the fuel used, also under conditions of simulation of road tests. Based on computer simulations of the given engine cycle, the impact of the use of biofuels on carbon dioxide emissions from a diesel and gasoline engine was analysed. The tested fuels were: gasoline 95, diesel, ethanol, DME dimethyl ether, and FAME fatty acid methyl esters. The differences in CO2 emissions of the tested fuels were large (up to 17%), but none of the analysed fuels exceeded the maximum emission limits allowed by legal regulations. The results of such simulations might be used for planning the development of various types of engines -possibly adjustable to fuels of various origin, as well as for planning the fuel composition assuring the best performance in a wide spectrum of engine constructions.

The use of various biofuels, usually of relatively small Lower Heating Value (LHV), affects the gas turbine efficiency. The present paper shows that applying the proposed air by-pass system of the combustor at the turbine exit causes tan increase of efficiency of the turbine cycle increased by a few points. This solution appears very promising also in combined gas/steam turbine power plants. The comparison of a turbine set operating according to an open cycle with partial bypassing of external combustion chamber at the turbine exit (a new solution) and, for comparison, a turbine set operating according to an open cycle with a regenerator. The calculations were carried out for different fuels: gas from biomass gasification (LHV = 4.4 MJ/kg), biogas (LHV = 17.5 MJ/kg) and methane (LHV = 50 MJ/kg). It is demonstrated that analyzed solution enables construction of several kW power microturbines that might be used on a local scale. Such turbines, operated by prosumer’s type of organizations may change the efficiency of electricity generation on a country-wide scale evidently contributing to the sustainability of power generation, as well as the economy as a whole.

An increase of needs for replacement of fossil fuels, and for mitigation of Carbon Dioxide emissions generated from fossil fuels inspires the search for new fuels based on renewable biological resources. It would be convenient if the biological component of the fuel required as little as possible conversion operations in the production. The obvious response is an attempt to use unconverted, neat plant oils as a fuel for Diesel engines. The present paper is devoted to the experimental studies of the combustion process of neat rapeseed oil, and its mixtures with gasoline and ethanol as additional components of the mixtures. The investigation of combustion was carried out in a fixed volume combustion chamber equipped with a Common Rail injection system. It is shown that the instant of ignition, as well as time-dependence of heat emanation, are strongly dependent upon mixture composition. The results enable the design of mixture compositions that could serve as commercial fuel for Diesel engines. Such fuels are expected to fulfill the requirements for the sustainability of road transport.

Economic progress, development of transport, production of new cars, production of more and more energy, and the combustion of fossil fuels are causing huge changes that are currently occurring in the environment. Ecological problems of the contemporary economy combined with perspectives of resources exhaustion, as well as the need to follow sustainable rules of living, require the search for new fuels. Fuels which can assure their availability and good environmental performance are needed for maintaining sustainable transportation. Knowledge about the behavior of various fuels is necessary for realistic methods of technology management in transportation means and the fuel industry. This paper describes biofuels that can be an addition to petrol or can exist as standalone fuels. A simulation was carried out on an urban vehicle and the tested fuels were petrol 95, ethanol, methanol, and dimethyl ether. For the selected engine a simulation corresponding to that of the New European Driving Cycle (NEDC) test was created using the Scilab package. Based on this simulation, values of carbon dioxide and water vapor emission were determined. The fuel demand for each fuel mixture and the amount of air for the fuels used were also calculated (and verified on the basis of laboratory tests). It was demonstrated that addition of biofuel decreases emission of carbon dioxide, simultaneously increasing emission of water vapor. Biofuel additive also caused an increase in fuel consumption. Unfortunately, in the New European Driving Cycle test being investigated, carbon dioxide emissions in all cases exceeded the permissible level of 130 g CO2/km, which is bad news in the context of the further tightening of norms and standards. The simulation tests confirmed that when using the start/stop system and applying specific additives, the carbon dioxide emission decreases and the consumption of mixtures with the activated start/stop system is smaller. The analyzed problems and results of this analysis become more important in light of the Worldwide Harmonized Light Duty Vehicles Test Procedure (WLTP) standard, which became binding from September 2018 and applies to the sale of cars that had been approved prior (in accordance with the New European Driving Cycle standard). Although the NEDC standard appears obsolete the computer model simulating this type of test will be necessary in many cases. It is, however, needed and possible to develop a similar simulation procedure for WLTP tests.

The power sector is currently experiencing a dynamic transformation, resulting not only from EU directives, but also from current problems, mainly related to ensuring energy security for customers. For this reason, in Poland, it was decided that the model of electricity market operation needed to be changed. A dual market has been created, and a separated segment is the capacity market. This solution operates, in addition to other power mechanisms, in many European Union countries, e.g., in France, Great Britain, and Italy. The experience of these countries indicates the positive impact of the power market on various aspects of the power sector, such as legal, economic, technical and technological, social, and infrastructural aspects, mainly due to technological neutrality and open competition between power suppliers. The creation of the structure of an energy market drastically changes the rules of energy management, which requires investigations concerning the impact of those factors on the energy sector in Poland. The aim of this work is to examine the impact of the power market on the Polish power sector, and to determine the impact of individual consequences on several predefined areas. For this purpose, a questionnaire survey was used. The purpose of a detailed analysis is to develop probable scenarios for the sustainable development of the Polish energy sector.

Rapeseed plantation biodiesel production systems require the transportation of goods, like raw materials, machines and tools, and products between various conversion stages of agricultural as well as industrial subsystems. Each transportation step requires the consumption of some energy. This consumption decreases the net amount of energy delivered out of the biofuel production system, and consequently decreases the energetic efficiency of the system. The majority of studies on biofuel sustainability are done by means of the LCA method with the use of a data average for some region and period of time. Such analyses do not reveal the possible causes of the conclusions determined. The present work deals with computer modelling of the influence of the energy consumed on those transport routes on the energetic efficiency of the production system. The model enables determination of the effects caused by changes introduced to technological parameters. The effects caused by variation of fuel consumption, the load capacity of transportation means, size of plantation, distribution and sizes of individual fields, distances between fields, plantation yield, and finally the distance between the plantation and the industrial facility are studied using the numerical model developed earlier. This approach is aimed towards identifying the reasons for the behavior of a system controlled by many somewhat coupled variables.