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Number of results: 20
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Abstract

Dr. Krzysztof Fic of the Poznań University of Technology discusses energy storage, aesthetic medicine’s quest for immortality, and how much time goes into being a scientist.
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Abstract

The main aim of this article is to present the results of research on energy poverty conducted in Katowice and Bytom, two cities situated in the Silesian voivodeship [region] in Poland. The study attempted to verify whether the energy divide concept elaborated by Bouzarovski and Tirado Herrero (2015) has different undiscovered dimensions which result not only from the differences in energy prices and incomes between various regions, but also from other factors such as consumer behaviours. In discussions about the energy divide, this aspect of energy poverty has so far been rather neglected. The question remains whether the distinction between energy poverty levels of countries, regions, and other territories like cities is determined by consumer behaviours or only by income and energy prices. Katowice and Bytom seem to be perfect places to conduct such. The most important conclusions emerging from the presented research are: (a) low income does not affect the behaviour of people suffering from energy poverty, even though it theoretically should; (b) despite their difficult financial situation, low-income households do little to improve their situation; and (c) public policy should take into account in the spatial distribution of households affected by energy poverty other aspects, including non-income and behavioural factors and patterns of persons affected by energy poverty, which only deepen existing social inequalities rather than reduce them.
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Abstract

The sustainable management of energy production and consumption is one of the main challenges of the 21st century. This results from the threats to the natural environment, including the negative impact of the energy sector on the climate, the limited resources of fossil fuels, as well as the unstability of renewable energy sources – despite the development of technologies for obtaining energy from the: sun, wind, water, etc. In this situation, the efficiency of energy management, both on the micro (dispersed energy) and macro (power system) scale, may be improved by innovative technological solutions enabling energy storage. Their effective implementation enables energy storage during periods of overproduction and its use in the case of energy shortages. These challenges cannot be overestimated. Modern science needs to solve various technological issues in the field of storage, organizational problems of enterprises producing electricity and heat, or issues related to the functioning of energy markets. The article presents the specificity of the operation of a combined heat and power plant with a heat accumulator in the electricity market while taking the parameters affected by uncertainty into account. It was pointed out that the analysis of the risk associated with energy prices and weather conditions is an important element of the decision-making process and management of a heat and power plant equipped with a cold water heat accumulator. The complexity of the issues and the number of variables to be analyzed at a given time are the reason for the use of advanced forecasting methods. The stochastic modeling methods are considered as interesting tools that allow forecasting the operation of an installation with a heat accumulator while taking the influence of numerous variables into account. The analysis has shown that the combined use of Monte Carlo simulations and forecasting using the geometric Brownian motion enables the quantification of the risk of the CHP plant’s operation and the impact of using the energy store on solving uncertainties. The applied methodology can be used at the design stage of systems with energy storage and enables carrying out the risk analysis in the already existing systems; this will allow their efficiency to be improved. The introduction of additional parameters of the planned investments to the analysis will allow the maximum use of energy storage systems in both industrial and dispersed power generation.
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Abstract

Mobile devices have become an integral part of our life and provide dozens of useful services to their users. However, usability of mobile devices is hindered by battery lifetime. Energy conservation can extend battery lifetime, however, any energy management policy requires accurate prediction of energy consumption, which is impossible without reliable energy measurement and estimation methods and tools. We present an analysis of the energy measurement methodologies and describe the implementations of the internal (profiling) software (proprietary, custom) and external software-based (Java API, Sensor API, GSM AT) energy measurement methodologies. The methods are applied to measure energy consumption on a variety of mobile devices (laptop PC, PDA, smart phone). A case study of measuring energy consumption on a mobile computer using 3DMark06 benchmarking software is presented
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Abstract

The aim of the research is to assess and discuss the diversity of energy production and consumption in European Union countries. The time scope covers the years 2007 and 2016. The diversity of EU countries was examined using the cluster analysis. The following diagnostic features were adopted for the analysis: energy dependency rate (in %), gross inland consumption of energy per 10,000 inhabitants (toe/10,000 inhabitants), primary production of energy (all products) per 10,000 inhabitants (toe/10,000 inhabitants), primary production of renewable energies per 10,000 inhabitants (toe/10,000 inhabitants), primary production of energy (without renewable energy) per 10,000 inhabitants (toe/10,000 inhabitants). Comparing the included indicators from 2016 to 2007 for all EU countries, an increase was recorded only for the primary production of renewable energies per 10,000 inhabitants,. Based on the cluster analysis, the examined countries were divided into six groups. According to the results of the research carried out, Northern and Eastern European countries are characterized by low energy dependence. However, according to the analysis carried out, this dependence is guaranteed based on various energy sources. The Scandinavian countries (Sweden, Finland) owe their high independence to the production of large amounts of energy from renewable sources. On the other hand, countries such as the Netherlands, Denmark, Estonia and the whole of Eastern Europe are based on primary energy sources such as: coal, oil and gas. Southern Europe countries (Greece, Spain, Italy, Portugal, Cyprus, Malta) are characterized by high energy dependence, as evidenced by low rates in the area of energy production, both in total and renewable and non-renewable energy production.
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Abstract

The predicted annual growth of energy consumption in ICT by 4% towards 2020, despite improvements and efficiency gains in technology, is challenging our ability to claim that ICT is providing overall gains in energy efficiency and Carbon Imprint as computers and networks are increasingly used in all sectors of activity. Thus we must find means to limit this increase and preserve quality of service (QoS) in computer systems and networks. Since the energy consumed in ICT is related to system load, ]this paper discusses the choice of system load that offers the best trade-off between energy consumption and QoS. We use both simple queueing models and measurements to develop and illustrate the results. A discussion is also provided regarding future research directions.
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Abstract

The paper presents a theoretical analysis of the effect of electric car performance characteristics on vehicle energy consumption and driving range. The test object was a Nissan Leaf electric vehicle. The characteristic curves of basic and additional resistance to motion (sum of rolling resistance and air resistance and inertia resistance or grade resistance, respectively) were applied to the model characteristic curve of electric motor torque of the tested vehicle. Based on that, the graphs describing the relationships between vehicle energy consumption and vehicle speed were made (for specific values of car acceleration / acclivity grade) as well as the relations between vehicle driving range and its traction properties. It was concluded that the use of performance characteristics significantly increased the vehicle’s energy consumption and decreased the available vehicle’s driving range.
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Abstract

This paper presents a study on the effect of cleaning factors on the energy consumption of the cleaning process in a CIP system, and the correlation between single components of electricity necessary to perform this process and the cleanliness degree obtained. Studies were carried out in a laboratory cleaning station, wherein a plate heat exchanger contaminated with hot milk was included. The research program was developed according to a 5-level statistical plan. Based on the results, obtained with Experiment Planner 1.0, a regression function of energy requirement considering variables such as: cleaning time, temperature and flow rate of the cleaning liquid via the cleaned exchanger has been developed. Describing this relationship, linear and quadratic functions with double interactions were used. Significance level for the analysis was established at α = 0.05. Correlation analysis between components of the electricity necessary to perform the cleaning process (pump drive and heating of the cleaning agent) and the resulting degree of cleaning of heat exchanger plates was performed.
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Abstract

The paper presents the simulation analysis determining the effect of tyre energy efficiency class on fuel consumption of a passenger car. Calculations were made assuming the wheel movement on a dry and smooth asphalt road surface. The tests based on a simulation model were performed on 61 types of tyres, being characterised by different sizes and energy efficiency classes. Different values of rolling resistance coefficient were adopted (in accordance with energy efficiency classes), also, the values of basic and additional resistance to motion were determined. Based on them, engine speeds and load torque corresponding to respective specific fuel consumption were estimated. This parameter allowed the relationship between average mileage fuel consumption and tyre energy efficiency class to be determined on the basis of the NEDC test.
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Abstract

This paper proposes an analysis of the effect of vertical position of the pivot point of the inverted pendulum during humanoid walking. We introduce a new feature of the inverted pendulum by taking a pivot point under the ground level allowing a natural trajectory for the center of pressure (CoP), like in human walking. The influence of the vertical position of the pivot point on energy consumption is analyzed here. The evaluation of a 3D Walking gait is based on the energy consumption. A sthenic criterion is used to depict this evaluation. A consequent reduction of joint torques is shown with a pivot point under the ground.
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Abstract

In this article, an outline of the key questions connected with the essential problems of energy-consumption of air-stream moulding machines has been presented. Research results and calculations of requisite parameters appraisable of energy-consumption of air-stream moulding machines have been supplemented also by the data analysis of offer of the moulding machines manufacturers. The attention on constructional and technological factors which are favourable for the diminution of energy-consuming of the moulding process has been paid.
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Abstract

This research presents a 3D FE method for the simulation of the variable reluctance stepper motor dynamics. The proposed model is used to obtain the optimal minimum energy control law that minimizes the energy injected by the controller. The method is based on the strong coupling of field - circuit equations and extended to eddy current, motion and nonlinearity problem. The linearization technique for the coupled problem is presented. Also the lamination of the motor core is considered. In the paper the open - loop control problem is analyzed. The proposed model is validated by the comparison with measurements. Next, to demonstrate the effectiveness of the proposed optimal minimum energy control method is applied. In both cases, the examination of the variable reluctance stepper motor dynamics and the steel loss in the core is presented and compared.
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Abstract

Energy efficiency improvement and ecological safety of heat power plants are urgent problems, which require scientifically grounded approaches and solutions. These problems can be solved partly within the presented heat-and-power cycles by including contact energy exchange equipment in the circuits of existing installations. A significant positive effectis obtained in the contact energy exchange installations, such as gas-steam installation ‘Aquarius’ and the contact hydrogen heat generator that also can use hydrogen as a fuel. In these plants, the efficiency increases approximately by 10–12% in comparison with traditional installations, and the concentration of toxic substances, such as nitrogen oxides and carbon monoxide in flue gas can be reduced to 30 mg/m3and to 5 mg/m3, respectively. Moreover, the plants additionally ‘generate’ the clean water, which can be used for technical purposes.
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Abstract

The article aims to evaluate the Portuguese building stock energy policies and strategy for energy saving in buildings among the EU members. It was found out the average heat transfer coefficients of the main structural elements of Portuguese Buildings and analyzed the U-values of this elements considering different time periods. The fundamentals of this study were funded by the Agency for Development and Innovation (ADI) and co-financed by the European Regional Development Fund (FEDER) through the Operational Program for Competitiveness Factors (POFC) assigned to the Building Physics and Construction Technology Laboratory with the reference SB Tool SPT_2011_4.
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Abstract

This paper presents the Life Cycle Assessment (LCA) analysis concerning the selected options of supercritical coal power units. The investigation covers a pulverized power unit without a CCS (Carbon Capture and Storage) installation, a pulverized unit with a "post-combustion" installation (MEA type) and a pulverized power unit working in the "oxy-combustion" mode. For each variant the net electric power amounts to 600 MW. The energy component of the LCA analysis has been determined. It describes the depletion of non-renewable natural resources. The energy component is determined by the coefficient of cumulative energy consumption in the life cycle. For the calculation of the ecological component of the LCA analysis the cumulative CO2 emission has been applied. At present it is the basic emission factor for the LCA analysis of power plants. The work also presents the sensitivity analysis of calculated energy and ecological factors.
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Abstract

The article presents the results of selected energy parameters calculations, carried out for the recorded values of instantaneous voltages and currents in the three-phase power supply of the model vibratory unit. The parameters were the values of active and apparent power taken from the drive consisting of two electric motors supplied by the inverter for selected frequency settings and directly from the power grid. In addition, calculations of tgφ power factor values were made to evaluate the compensation of reactive power consumption in the tested power systems. Measurements and calculations lead to the conclusion that if the frequency of the inverter output voltage rises, the active and apparent power consumed by the model vibratory drive unit increases. The active and apparent power for setting the output frequency of the inverter from 50 Hz was less than the active and apparent power taken by the model vibratory unit that was powered directly from the power grid. The power factor tgφ in the power supply system was approximately 6, except one case (f = 30 Hz).
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Abstract

Oxy-fuel combustion (OFC) belongs to one of the three commonly known clean coal technologies for power generation sector and other industry sectors responsible for CO2emissions (e.g., steel or cement production). The OFC capture technology is based on using high-purity oxygen in the combustion process instead of atmospheric air. Therefore flue gases have a high concentration of CO2- Due to the limited adiabatic temperature of combustion some part of CO2must be recycled to the boiler in order to maintain a proper flame temperature. An integrated oxy-fuel combustion power plant constitutes a system consisting of the following technological modules: boiler, steam cycle, air separation unit, cooling water and water treatment system, flue gas quality control system and CO2processing unit. Due to the interconnections between technological modules, energy, exergy and ecological analyses require a system approach. The paper present the system approach based on the 'input-output' method to the analysis of the: direct energy and material consumption, cumulative energy and exergy consumption, system (local and cumulative) exergy losses, and thermoecological cost. Other measures like cumulative degree of perfection or index of sustainable development are also proposed. The paper presents a complex example of the system analysis (from direct energy consumption to thermoecological cost) of an advanced integrated OFC power plant.
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Abstract

This paper presents a design of a tracked in-pipe inspection mobile robot with an adaptive drive positioning system. The robot is intended to operate in circular and rectangular pipes and ducts, oriented horizontally and vertically. The paper covers a design process of a virtual prototype, focusing on track adaptation to work environment. A mathematical description of a kinematic model of the robot is presented. Operation of the prototype in pipes with a cross-section greater than 210 mm is described. Laboratory tests that validate the design and enable determination of energy consumption of the robot are presented.
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Abstract

Higher active power of a submerged arc furnace is commonly believed to increase its capacity in the process of ferrosilicon smelting. This is a true statement but only to a limited extent. For a given electrode diameter d, there is a certain limit value of the submerged arc furnace active power. When this value is exceeded, the furnace capacity in the process of ferrosilicon smelting does not increase but the energy loss is higher and the technical and economic indicators become worse. Maximum output regarding the reaction zone volumes is one of parameters that characterize similarities of furnaces with various geometrical parameters. It is proportional to d3 and does not depend on the furnace size. The results of statistical analysis of the ferrosilicon smelting process in the 20 MVA furnace have been presented. In addition to basic electrical parameters, such as active power and electrical load of the electrodes, factors contributing to higher resistance of the furnace bath and resulting lower reactive power Px demonstrate the most significant effect on the electrothermal process of ferrosilicon smelting. These parameters reflect metallurgical conditions of ferrosilicon smelting, such as the reducer fraction, position of the electrodes and temperature conditions of the reaction zones.
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