Energy Conversion Coefficient Research Articles

Analysis of the influence of the ambient temperature on the energy efficiency of solar modules by application of empirical correlations for natural convection

In this paper, the effect of the ambient temperature on photovoltaic (PV) modules for different angles of inclinations and different intensities of the solar radiation on the surface of PV module is considered using empirical correlations for natural convection. The analysis used an analytical model based on the energy balance equilibrium between PV module and the environment. It has been shown that in real conditions of exploitation, the value of the solar conversion coefficient of the solar energy to be determined by the manufacturer, valid for the standard test conditions (STC) for PV module (25 °C -1000 W/m2). The results obtained indicates that in the case a smaller number of PV modules corresponding to the required number for average household. The proposed procedure can be applied in the techno-economic analysis for PV system with uniaxial monitoring of the sun position as well as static PV systems.

Technique for testing small wind turbines by method of acceleration in the wind tunnel and in the field

A technique is proposed for obtaining aerodynamic and mechanical characteristics of wind turbines – the wind energy conversion coefficient and the relative torque of the wind turbine as a function of their speed with respect to the intensity of the wind wheel acceleration from the moment of its start until the synchronous speed at constant wind speed. The proposed technique simplifies and significantly reduces the time for experimental testing of wind turbine wheels.

Impact of spatial structure of urban agglomeration on carbon emissions: An analysis of the Shandong Peninsula, China

Given that carbon emissions continue to contribute to global warming, strategies to achieve reductions in emissions have become a focus for research. The study of the impact of spatial structure of urban agglomeration on carbon emissions has important significance with respect to exploring ways to reduce carbon emissions. The urban agglomeration in the Shandong Peninsula, China was selected as a case study. The spatial structure of urban agglomeration was measured from the perspectives of single-center and multi-center, concentration and diffusion, spatial compactness, and transportation accessibility. Carbon emissions were measured using the standard energy conversion coefficient for coal as well as via coefficients for alternative energy sources. The impact of the spatial structure of urban agglomeration on carbon emissions was assessed via regression analysis. The results revealed that: (1) The impact of multi-center characteristics on carbon emissions was not significant and should be verified using more samples; (2) Concentration and transportation accessibility exerted a positive impact on carbon emissions, therefore, the mode of urban-rural integration and low carbon transportation systems must be taken into account; (3) Spatial compactness exerted a negative impact on carbon emissions, therefore, the patterns of compactness need to be adjusted and optimized.

Mineralogical Analysis of Selective Melting in Partially Coherent Rockslides: Bridging Solid and Molten Friction

AbstractFrictional shearing along the basal slip surface is the main energy dissipation mechanism in coherent landslides, which undergo little internal deformation during runout. Most landslide bodies, however, deform and break down more or less extensively; thus, only a portion of their potential energy is dissipated through basal shearing. The mineral components of rocks and soils have individual melting temperatures. Therefore, as temperature increases, selective melting will occur in a defined sequence. The product of such melting is termed frictionite. Here, we exploited a sliding block model to investigate the role of selective melting in the evolution of the frictional resistance (and hence mobility) of partially coherent landslides. We recognized three frictional stages, characterized by weakening, strengthening, and melt lubrication. As melting proceeds, a gradual transition from solid friction to viscous flow occurs, which can be modeled in terms of the molten mineral fraction. The chemical composition also evolves and so does its viscosity. Rocks with different mineral proportions (e.g., mafic vs. felsic rocks) will exhibit different frictional evolutions. Our model results are consistent with the recognized role of landslide thickness in defining its mobility. Moreover, the frictional strengthening stage is shown to become irrelevant under high confinement, thereby facilitating higher mobility, or sometimes shifting slip surface if weak layer exists. We also discussed the relevance of some strengthening‐upon‐melting behavior observed at the experimental scale, pointing out the role of the energy conversion coefficient, which is a proxy for landslide coherence.

Ultrahigh field-induced strain in lead-free ceramics

Abstract Due to the worldwide concerns of environmental protection and sustainable development, lead-free piezoelectric materials are greatly desired for bridging the electrical energy to the mechanical energy. However, their lower energy conversion coefficient compared to the conventional lead-containing piezoelectric materials significantly limits their device applications. Herein, we introduce a novel strategy to increase the strain of lead-free ferroelectric system via material structure design to create polar nano regions (PNRs) and point defects in the material while retaining the global ferroelectric phase. This added short-range structural heterogeneity in the material will facilitate the field-induced phase transition and reversible domain wall switching to enhance the strain. Following this strategy, we demonstrate an ultrahigh strain induced by an electric field in non-textured lead-free Bi0.5Na0.5TiO3 (BNT)-based ceramics. The strain in unipolar mode (Suni) can reach up to 0.74% at 70 kV/cm, making it the highest value in reported lead-free ceramics so far. This puts forward a good route to design high-performance piezoelectric materials by material structure engineering. It also reveals the promising potential of lead-free piezoelectric materials in practical electromechanical device applications.

ANALYSIS OF A DOUBLE-BEAM e,X-MODE AT AN IDUSTRIAL ACCELERATOR “EPOS”

The main assignment of industrial plant with an accelerator “EPOS” providing the electron energy up to 30 MeV is radiation dyeing of gemstones. At treatment of them, the part of the electron energy is transformed into bremsstrahlung (X-) radiation. The energy characteristics of the electron beam were measured by a dosimetry wedge technique. On the basis of obtained results, the parameters of the mixed e,X-flux (the energy conversion coefficient and the factor of secondary radiation) along the path of radiation formation were calculated using a transport code GEANT4. The conditions for production of X-ray radiation in the state of electronic equilibrium have been determined. The spectrum of the X-ray photons as well as the dose rate and its distribution behind a target device for gemstone irradiation were calculated. A measured dose profile is satisfactory agreed with the data of the simulation. Implementation of a double-beam mode enables to conduct the extra radiation programs in the field of the bremsstrahlung radiation (modification of semiconductors and polymers, radiation tests, photonuclear activation of samples, etc.).

Farm Grain Dryer with a Heat Pump and Its Calculation

The initial premises of using a heat pump are that in winter (a cold period of a year) it is used to heat a farmhouse and in summer (a warm period), when heating the house is not required, it is used as part of a grain dryer. Analysis of the operation of a batch fluidized-bed grain dryer for maize seed grains (loading 75 kg), equipped with a heat pump for heating the drying agent, is performed. It is assumed that the source of low-potential heat in the heat pump is groundwater with a temperature of 6°C at the inlet of the heat exchanger and 8°C at the outlet, and the drying agent (air) is heated in the condenser of the heat pump up to 60°C. Freon R600a was chosen as the working body in the heat pump. It is shown that, under these conditions, the heat pump operated at the refrigeranttemperature in the evaporator of 3°C and its temperature in the condenser of 70°C makes it possible to reduce the consumption of heat for heating the drying agent by ~66% (the energy conversion coefficient is 2,98), and the use of partial recycling of the spent drying agent saves another 25% of energy. The analysis provides evidence for good perspectives of using a heat pump dryer in farms. A technique is developed for kinetic calculation of a batch fluidized-bed dryer for a granular material, taking into account the non-steady-state nature of the drying process. The technique is based on an analytical solution of the problem of mass conductivity for individual grains, makes use of the zonal method of calculation, and takes into account changes in the parameters of the drying agent during the process, both over the height of the fluidized bed and in time. The adequacy of the mathematical model for calculating the drying kinetics to the real process is demonstrated.

БИОЛОГИЧЕСКОЕ ДЕЙСТВИЕ НАНОЧАСТИЦ ОКСИДА КРЕМНИЯ НА ОРГАНИЗМ ЦЫПЛЯТ-БРОЙЛЕРОВ

The aim of the study is to increase the productive qualities of broiler chickens by including ultrafine silicon oxide into main diet. During the experiment, the biological effect of ultrafine silicon oxide on broiler chickens was estab-lished. Use of ultrafine SiO2 particles for poultry feeding contributed to an increase in the number of red blood cells and content of total protein and albumins. By the end of the experiment, the number of red blood cells in birds in-creased by 17.43% (P≤0.001) – in the blood of birds of the first experimental group, 16.51% (P≤0.01) – the second one, 20.80% (P≤0.001) – the third experimental and 21.71% (P≤0.001) – the fourth experimental group, compared with the indicator of the control group. The amount of total protein in blood serum of chickens of the first and the second experimental groups increased by 1.36-1.39 %, in the third and fourth ones there was a significant (P≤0.05) increase by 5.45 and 3.05%, respectively. The blood glucose content of chickens in the experimental groups is higher by 8.04-23.65% compared to this indicator with ones in the control group. During the experiment feed con-sumption per 1 kg gain of live weight decreased: in the first experimental group by 3.00 % in the second by – 0.50 %, the third – 6.00 % the fourth– by 4.50 %, compared to this with the control group. The chicken’s vibrancy of the first the experimental group was higher by 4.77 %, the second – by 6.20 %, the third – by 19.25 % and the fourth– by 11.59% than in the control one. Consequently, when converting the feed energy into the body energy of a broiler chicken, the energy conversion coefficient of the experimental group of poultry is higher than that of the control one by 7.16-21.76 %. Thus, the most optimal dose for further research was determined.

The evolution of magnetic field and spin‐down of young pulsars

AbstractHere, we summarize our recent work on the evolution of magnetic field and spin‐down of young pulsars including high‐B pulsars and magnetars. Our work includes the following three parts: (a) Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of the mean braking indices of eight magnetars with SNRs and find that five magnetars have smaller mean braking indices of 1 < n < 3, and we interpret them within a combination of magnetodipole radiation and wind‐aided braking. (b) The low braking index of n = 0.9(2) for PSR J1734‐3333 could undergo a supercritical accretion soon after its formation in a supernova explosion. The buried multipole magnetic fields will merge into a dipole magnetic field. Retaining the current field growth index ϵ = 1.34, this pulsar will become a magnetar with dBp∼6.2(2) × 1014 G and dBp∼1.06(4) × 1015 G after 50 kyrs and 100 kys, respectively. (c) By introducing a mean rotation energy conversion coefficient and combining the pulsar's high‐energy and timing observations with a reliable nuclear equation of state, we estimate the initial spin period, initial dipole magnetic field, and true age of PSR J1640‐4631. For this source, its measured high braking index n = 3.15(3) is attributed to a long‐term dipole magnetic field decay, and its soft X‐ray emission is attributed to anisotropic heating.

The Efficiency of Using Simmental x Holstein Hybrids of Various Types of Body Composition

In crossbred cows, three exterior and body composition types are distinguished: dense shallow, dense medium, and dense broad. Cows of broad type were superior to their peers of shallow type in height at the withers by 3.98 cm, by chest depth by 3.33 cm, by chest width by 8.25 cm, by chest girth by 5.5 cm, and by the slope body length by 5.37 cm. Cows of the medium type take an intermediate position. The share of the cows of the broad type is 67.5 %, they have a broader body, have an advantage in the indices of the breast width (5.5 – 9.2 %, P ≤ 0.001), and pelvic-thoracic width (7.2 – 13.1 %, P ≤ 0.001), but are inferior in the index of leg length (0.6 – 0.9 %). During the first lactation, heifers of shallow type gave 5,353 kg of milk, which was more by 500 – 539 kg than from heifers of the medium and broad types (P ≥ 0.99). In terms of the live weight, the calves obtained from the mothers of the broad type are superior to their peers at birth by 1.6 – 2.5 kg; at the age of three months, the difference between the groups of animals reached 8.0 – 13.0 kg (P ≤ 0.01, P ≤ 0.001); at the age of six months —15.0 – 25.0 kg (P ≤ 0.001); at the age of nine-months — 17.0 – 28.0 kg (P ≤ 0.001); at the age of twelve months — 25.0 – 44.0 kg (P ≤ 0.001); at the age of fifteen months — 25.0 – 46.0 kg (P ≤ 0.001); and at the age of eighteen months — 30.0 – 52.0 kg (P ≤ 0.001). By the weight of hot carcass, calves of the broad type were superior to their peers of the shallow type by 38.9 kg (P ≤ 0.01), and to those of the medium type — by 23 kg (P ≤ 0.05). The yield of boneless meat per 1 kg of bones in the calves of the shallow type was 3.87 kg, of the medium type — 4.10 kg, and of the broad type — 4.22 kg (P ≤ 0.05). The coefficient of feed protein and energy conversion to the dietary protein in the edible part of the carcass was higher in the calves of the broad type, which was due to the more intensive accumulation of muscle and adipose tissues in their organisms.

Analytical description of the size effect on pyroelectric and electrocaloric properties of ferroelectric nanoparticles

Using Landau-Ginzburg-Devonshire theory and effective medium approximation, we analytically calculate typical dependences of the pyroelectric and electrocaloric coefficients on external electric field, temperature and radius for spherical single-domain ferroelectric nanoparticles. The considered physical model corresponds to the nanocomposite with small fraction of ferroelectric nanoparticles. Within the framework of the analytical model we establish how the size changes determine the temperature and field behavior pyroelectric and electrocaloric coefficients on example of BaTiO3 nanoparticles covered by a semiconducting shell and placed in a dielectric polymer. We show that by changing the particle size one can induce maxima of the pyroelectric coefficient and electrocaloric temperature variation, control their width, height and sign. Obtained analytical expressions allow selecting the interval of particle sizes, voltage, and/or temperature for which pyroelectric energy conversion and electrocaloric coefficient are optimal for applications. The observed size effect opens the possibility to control pyroelectric and electrocaloric properties of ferroelectric nanocomposites that can be important for their advanced applications in energy convertors and cooling systems.

Study of Luminescence in Noble Gases and Binary Kr-Xe Mixture Excited by the Products of 6Li(n,α)T Nuclear Reaction

At the present time the direct nuclear energy conversion into optical radiation is realized in gas media in which filling of energy levels takes place in the low-temperature plasma (nuclear-excited plasma) induced by ionizing radiation. The research of optical radiation of the nuclear-excited plasma induced by products of nuclear reactions is interest for development of an alternative outlet method of energy from the nuclear reactor, creation of control and regulating bodies for parameters of nuclear reactors as well as creation of one of diagnostics of high-temperature plasma in fusion reactors. The purpose of this work was to obtain new experimental data about processes of nuclear energy conversion into optical radiation with the optimal gas media having high coefficient of nuclear energy conversion into optical radiation and also with a possibility of outlet method of energy from the nuclear reactor core. In this article, description of the reactor experimental bench (LIANA) and the experiment scheme, the irradiating ampoule device (AD) with surface source of charged particles is provided, and the procedure of reactor experiment is presented. This paper presents the results of the reactor experiments of studying the spectral-luminescent characteristics of unary noble gases (Ne, Ar, Kr, Xe) and binary Kr-Xe gas mixture in a 200–975 nm spectral range with ionization gaseous media by products of 6Li(n,α)T nuclear reaction under irradiation at research water-cooled heterogeneous reactor (the IVG.1M).

On-farm heat pump - assisted fluidized bed dryer and its kinetics calculation

The expediency of using the heat pump (HP) as a part of the farm drying plant is considered taking drying corn grain in a batch fluidized bed (FB) as an example. Using the HP, it is possible to heat the air supplied to the dryer to a temperature about 60 °C. The refrigerant R600a (isobutаne) is selected as the working medium. According to analysis of a thermodynamic cycle of the HP, it was found that the energy conversion coefficient is equal to 2.98. The use of the HP allows saving 66% of the energy needed for corn drying. A mathematical model has been developed for the kinetic calculation of a drying plant with a batch FB for granular materials, based on the use of an analytical solution to the problem of mass conductivity and taking into account the changes in drying agent parameters over time and the bed height. The adequacy of model to the real process is shown.

Modern Power Engineering in the Light of the New Physical Representations and Technical Realizations. – A brief review

The perspective hypothesizes and elaborations represented in the special science literature and directed on the search of the new sources which are based on the physical principles of the energy extraction from the surrounding space are illuminated in the brief review. The so named “without-fuel” generators as the convertors of the different views of energy of the ether are described. Their elaboration becomes the more and more perspective business for solution of the modern energy problems. Their technical projects are passing to the state of the industrial production. According to the physical signs of the principle effectiveness, heat generators, magnetic dynamic convertors, convertors of gravitational energy and, finally, electrodynamics alternators are distinguished among them. In comparison with heat generators, the class of alternators using permanent magnets is more numerous and diverse. Convertors of gravitational energy are, as a rule, perpetuum mobiles containing structural components in which falling vertically downward weights or water are rotating the wheel, producing useful work. The selected group of the without-fuel generators is the electrodynamics alternators, working as convertors of the electromagnetic energy from the ether of the surrounding space. The most interesting example of electrodynamics alternators is the transformer Tesla known to a wide range of specialists. Its distinctive feature is an unusually high energy conversion coefficient (k>1000), much higher than the transformation ratio due to the inductive coupling between its windings. In conclusion, based on a comparison of analogs, a hypothesis on resonant phenomena as keys of access to ether energy in the surrounding space is formulated.

Handedness-controlled and solvent-driven actuators with twisted fibers

Handedness-controlled actuating systems are constructed from continuous twisted fibers with mirrored handedness, superb flexibility and mechanical robustness, affording impressive start-up torques driven by polar solvents, and controllably outputting rotor kinetic energy, harvesting electrical energy, and delivering mechanical energy with a high energy conversion coefficient.

Development of a control system to cover the demand for heat in a building with algae production in a bioenergy façade

In the present study a control system was developed and tested which allowed to maintain an optimum of both heat and microalgae production in a bioenergy façade and use of the heat to supply a residential building with hot water and heating. The control was developed for and implemented in the residential building BIQ Das Algenhaus, Hamburg, Germany. It automatically operates all system components of the 170 m² bioenergy façade as well as the management utilities which supply the building with heat. During a one-year monitoring in 2017/18, it was shown that the temperature in the culture medium of the bioenergy façade could be kept at the optimal cultivation temperature range between 20 and 35 °C. In addition to the biomass production, the façade produced heat as a result of the solar radiation. This heat has been extracted from the façade and utilized as a heat source for the building's supply system. The ratio between the solar radiation on the façade's surface and the heat produced – called energy conversion coefficient – was 0,38 across the year. The system supplied 59% of the building's annual total heat consumption of 63 MWh/a for hot water and heating. In the months May to August, the bioenergy façade served as the sole primary heat source for the building and the 50% surplus heat were stored in the soil below the building. The heat stored in the soil resulted in a regeneration of the soil temperature and allowed to cover the heat demand during winter.80% of the heat extracted from the façade were used instantaneously and without intermediate storage. This indicates that the control optimally regulates the heat flows for direct use and thus minimizes storage losses.The results show that bioenergy façades can be perfectly integrated into cities to help transfer them from being places of abundant resource consumption to places of production of resources by producing heat and biomass concomitantly.

Energy analysis of broiler chicken production system with darkhouse installation

ABSTRACT The objective of this study was to evaluate the sustainability of a broiler chicken production system, with confinement in Darkhouse sheds, by energetic analysis. Energy flows of a complete production cycle, 56 days, were considered, of which the energy inputs and outputs were computed in direct and indirect forms, by estimating the energy coming from the quantity of feed, water, machinery and equipment, human labor, sheds, silos, among other components of the productive system, multiplied by their respective energetic coefficients. The total energy demand of a system in a production cycle for the production of 1 kg of live chicken and its energy efficiency coefficient were determined. The studied system had energy conversion coefficient of 95%, demonstrating that the production model has high energy conversion efficiency and fits a sustainable model. On average, 37.55 MJ kg-1 of live chicken were necessary. The main limiting point of the system corresponded to the energy consumed in the form of feed, with 75% of the total direct energy.

Research on a Plug-In Hybrid Electric Bus Energy Management Strategy Considering Drivability

Plug-in hybrid electric buses (PHEBs) is some of the most promising products to address air pollution and the energy crisis. Considering the switching between different working modes often bring about sudden changes of the torque and the speed of different power sources, which may lead to the instability of the power output and affect the driving performance and ride comfort, it is of great significance to develop a real-time optimal energy management strategy for PHEBs to achieve the optimization of fuel economy and drivability. In this study, the proposed strategy includes an offline part and an online part. In the offline part, firstly, the energy conversion coefficient s(t) is optimized by linear weight particle swarm optimization algorithm (LinWPSO), then, the optimization results of s(t) are converted into a 2-dimensional look-up table. Secondly, combined with three typical driving cycle conditions, the gear-shifting correction and mode switching boundary parameters that affect the drivability of the vehicle are extracted by dynamic programming (DP) algorithm. In the online part, combined with the s(t), the gear-shifting correction and mode switching boundary parameters which are obtained through offline optimization, the real-time energy management strategy is proposed to solve the trade-off problem between minimizing the fuel consumption and improving the drivability and riding comfort. Finally, the proposed strategy is verified with simulation, the results show that the proposed strategy can guarantee the engine and the electric motor (EM) work in the high-efficiency area with optimal energy distribution while keeping drivability in the variation of driving circle. The overall performance is improved by 18.54% compared with the rule-based control strategy. The proposed strategy may provide theoretical support for the optimal control of PHEB.

Granular flow characteristics and heat generation mechanisms in an agitating drum with sphere particles: Numerical modeling and experiments

This work focuses on mechanism of heat generation in an agitating drum with dense gas-solid flow where particles move at high velocity (30 m/s). Numerical simulations and experiments are used to study the influence of granular flow characteristics, design parameters, process parameters and particle properties in heat generation and energy-conversion coefficient. Heat generates from sliding friction, rolling friction, viscous force of liquid-bridge or the modeled particle deformation. The variable goes to liquid volume due to high temperature (533 K) in wet particle flows. Concerning the velocity and particle motion several thermal transfer models are modified to match particle/particle and particle-wall/blade collisions, which are integrated to DEM-CFD numerical simulation. Experiments detected the temperature of external drum wall, the effect of temperature on liquid phase and the granular motion by visualization tests. The numerical results are verified by experimental data with good agreements. The effects of agitating speed and initial filling degree on temperature increase are not always in positive correlation, which are more significant in wet particles flow. Numerical simulations predicted the dynamic particles characteristic, the heat resources and the thermal conduction to reveal the heat generating mechanisms. Besides, the improved blades design to enhance heat generation is analyzed qualitatively and deduced.

The Means to Improve Water Treatment and to Enhance Power Engineering Performance of the Water Source Heat Pump

The subject matter of the paper is related to scientific-and-theoretical basis of power engineering characteristics of heat pump directly depending on the quality of treated water for reliable and uninterrupted operation of heat pump evaporator and compressor. On the basis of experimental data, energy parameters of the heat pump are calculated. The method of the combined technology of the heat pump “water – air” operation is considеred, the efficiency of which is based on the preliminary improvement of the quality of water softened with the use of a membrane ultrafiltration unit. This solution made it possible to reduce the load on the filters and to exclude the use of chemical reagents used in the classical schemes of water heating facilities. In order to improve the operation of the heat pump compressor, a method based on altering the speed of rotation of the shaft by means of electronic microprocessor devices has been proposed. To regulate the compressor performance, a frequency converter with a wide range of alternating current frequency is used. The intervals of alteration of frequency of the alternating current corresponding to energy-efficient values of coefficient of transformation of energy of the heat pump are investigated. The values of the energy conversion coefficient of the heat pump obtained in the course of experiments and determined by calculation are consistent within the experimental errors with the regulation of the compressor performance. The suggested experimental device made it possible to determine the dependence of the main characteristics of the unit of the heat pump unit on the number of revolutions of the compressor and to find out an effective range of its control (50–180 %). The development of advanced technologies for natural water treatment under conditions of increased anthropogenic loads on natural water sources is a priority one among the fundamental and applied research in the field of water treatment.