bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developing and modelling the invert boiler furnace for A-USC steam parameters
Authors: Prokhorov V B , Chernov S L , Kirichkov V S , Fomenko N E 
Published: July 2020

Abstract
Department of Thermal Power Plants of MPEI proposed the concept of a boiler of 1000 MW for advanced ultra-supercritical parameters steam generation with M-shaped profile with invert furnace and output collectors which are located under a sloping gas boiler pass. The feasibility of using ultra super supercritical parameters is associated with the possibility of increasing the unit efficiency by 4.2%. The proposed scheme of coal combustion is a system of vertical-horizontal tangential flames. For the analysis of the scheme it is offered to use physical and mathematical methods of modeling of the boiler furnace. Physical modeling allows determining the trajectories of jets and revealing their ejection capacity. Mathematical modeling is carried out using the ANSYS aerodynamics computing complex and provides an opportunity to validate and verify the results obtained on the physical model. Then with the help of the ANSYS program, the modeling of the combustion process in a full-scale version of the boiler furnace will continue. These methods are used at the Department of Thermal Power Plants of MPEI for solving problems of the organization of aerodynamics and combustion in the boiler furnaces of power boilers with traditional profiles and can be applied to research solutions for boilers of new generations.
Model of fuel spray propagation in direct injecting internal combustion engines under cross-flow conditions
Authors: Zueva T S , Garyaev A B , Weiss L 
Published: July 2020

Abstract
This paper is devoted to modelling of the fuel spray propagation into a cylinder of direct injecting internal combustion engines. A number of experiments were carried out to obtain data for the calculation of velocity profiles inside the spray, as well as its trajectory under cross-flow conditions. A one-hole injector was used in the experiments. The injection pressure varied from 100 till 150 bar and the air cross-flow velocities ranged from 0 till 50 m/s. The semi-empirical model was developed to describe the fuel spray propagation. The results obtained from the model and experiments were compared. The agreement of the results from experiments and the model for low velocities of the cross-flow (0-25 m/s) is significant. However, for high velocities of the cross-flow (30-50 m/s) the agreement is low. Thus, in this paper the improved model of the fuel spray propagation is proposed. A new model is based on splitting spray into parts with different densities. Each part moves with its own velocity and along its own trajectory.
Modelling grain active ventilation process in the silos
Authors: Berezina T S , Vlasenko G P 
Published: July 2020

Abstract
Changes in grain raw material properties in a complex thermophysical process are presented in the article, and a multifactorial mathematical model for developing engineering solutions for active ventilation is obtained. A numerical study of non-stationary changes in temperature and moisture content in a one-dimensional grain layer along with the height of a metal silo depending on environmental conditions is carried out. The simulation of the temperature and moisture fields in siloses is important for assessing the state and determining the parameters of the active ventilation system. The results show a significant air velocity effect on cooling and the speed of the drying process. The overall duration of drying and cooling of the grain top layer depends slightly on the initial parameters of the air such as the temperature and the moisture content. The obtained model is reliable to predict the drying kinetics for different storage conditions and different grain types. With the help of the presented model, it is possible to substantiate the safe grain storage modes in conditions of heterogeneity and temporal variations of standard parameters (temperature, air humidity).
Technology of Thermal Preparation of Coal for Ecologically Pure Combustion of Fuel in Small Boilers
Authors: Maysyuk E P , Kozlov A N 
Published: July 2020

Abstract
The problems of ecologically clean coal combustion are connected with the need to reduce the formation of pollutants to the environment during thermal transformation of fuel. Currently, about 180-190 million tons of coal are burned in Russia to produce heat and electricity, with more than 60% in the eastern regions of the country. Most of the coal (about 80%) is consumed by large thermal stations, which are equipped with pollutant trapping systems. The remaining part is burned in numerous boiler houses that operate in both urban and rural areas to provide heat to social facilities and the population. The analysis shows that the role of boiler houses increases significantly in the territories with a low population or in remote and decentralized areas. In this regard, the coal pretreatment technology before burning including the thermal preparation of coal is important. The use of thermally prepared fuel (semi-coke) will significantly reduce emissions of NOx and SOx, as well as improve the “culture” of thermal energy production at small boilers by switching to fully automated technologies, as well as significantly reducing the financial burden of utilities by reducing the wage fund and emission fees.
Special modes of diffusion mass transfer in isothermal triple gas mixtures
Authors: Kossov V N , Fedorenko O V , Mukamedenkyzy V , Kalimov A 
Published: July 2020

Abstract
In isothermal three-component gas mixtures in quasi-stationary conditions the procedure of numerical solution of Stefan-Maxwell diffusion equations using the software package “MathCad” is considered. It is shown that one of the specific features of multicomponent diffusion is the appearance of nonlinear concentration distributions of components in vertical channels. Due to the difference in the coefficients of mutual diffusion of gases in some systems under certain conditions, nonlinear distributions of component concentrations lead to a non-monotonic distribution of the density of the gas mixture. By the example of hydrogen – nitrogen – methane and methane – n-butane – nitrogen systems at a constant temperature T = 298 K, the influence of the content of the component with the highest molecular weight in the triple gas mixture on the degree of nonlinearity of the density distribution in the diffusion channel is analyzed. It is suggested that the inversion of the density distribution of the mixture may be the cause of convective instability in triple gas systems. The results of calculations are compared with experimental data.
Use of gasifier-based electric power stations for improving the economy of autonomous power supply systems in Russia
Authors: Marchenko O V , Solomin S V , Kozlov A N , Shamansky V A 
Published: July 2020

Abstract
In Russia, significant amounts of waste of logging and woodworking that can be used for energy production are generated. In this paper, we consider an autonomous power supply system, including a wood biomass gasification power plant (BGPP), a diesel power plant (DPP), one or several wind turbines (WT), and electricity consumers with their load schedule. The mathematical formulation of the problem of optimizing the structure and modes of operation of the power supply system is reduced to minimizing the objective function with a number of additional constrains. The objective function is equal to total discounted costs for the construction and operation of the system or the cost of electricity produced. Additional constrains are balances for power, primary, secondary and final energy. The power supply system was modeled for different values of diesel and wood fuels prices, average long-term wind speed, technical and economic indicators of power plants. According to the results of calculations, the zones of technologies efficiency and the cost of electricity produced are determined. It is shown that biomass gasification power plants with gas storage tanks are much more economical than diesel power plants and can displace them at current diesel fuel prices. In areas with high average annual wind speeds, biomass gasification power plants should be used in conjunction with wind turbines.
Numerical simulation of submicron particles formation during the combustion of coals, taking into account coagulation and dust content of combustion products
Authors: Kortsenshteyn N M , Petrov L V 
Published: July 2020

Abstract
Homogeneous-heterogeneous bulk condensation of potassium sulfate vapor has been numerically simulated in a dusty vapor-gas flow of coal combustion products upon their cooling along a technological path. A closed model that we have proposed for the formation of submicron particles in coal combustion products has been employed. Data on the concentration of particles formed at varied parameters of heterogeneous condensation sites have been obtained. Variations in the relative contributions of the homogeneous and heterogeneous mechanisms with variations in flow dustiness have been considered. Data on the influence of coagulation processes on the parameters of submicron particles resulting from coal combustion have been presented.
Physical features of fluid and structure interaction inside power unit pipeline vibration-isolating expansion joints
Authors: Kiryukhin A V , Milman O O , Sereshkin L N , Korljakova M O , Miloserdov V O 
Published: July 2020

Abstract
The calculation and experimental studies of vibration transmission through the pipeline compensators with liquid were carried out. No publications have been found among the scientific papers published on this issue. It has been demonstrated that the influence of structural resonances and the interaction of working medium pulsations with the structure increases vibration transmission through the compensator by two to three orders of magnitude or more with increasing frequency. The physical and mathematical models of this phenomenon are described, and a comparison of calculation and experiment is given. The ways of using the found interaction of medium pulsation and the structure to reduce vibration transmission by ten or more times within a certain frequency range are shown.
A method for calculating the aviation fuel O2 saturation process parameters
Authors: Kitanina E E , Kitanin E L , Bondarenko D A 
Published: July 2020

Abstract
This paper presents and substantiates the method of processing of the experimental data obtained from the experiments related to air sparging through the jet fuel layer. The experimental data was collected by Henshaw and Lam during the study addressed to oxygen re-absorption characteristics of an oxygen depleted, quiescent Jet A-1 fuel when sparged with air. In this study we accepted the hypothesis that the experimental results should be described primarily based on physical knowledge of the process and common techniques used for the description of individual components of the mass transfer process in sparging. The proposed calculation method of sparging mass transfer is valid for sparging through porous surfaces with pores of 1 μm or less, with large groups of small bubbles forming in the fuel. Moreover, the proposed method has been well-tested in the parameter range used in the underlying experiments and needs to be thoroughly checked beyond this range.
The influence of intense preliminary mechanical processing on the slag formation in coal-fired utility boilers
Authors: Chernetskiy M Yu , Butakov E B , Burdukov A P 
Published: July 2020

Abstract
Burdukov et al. [1] showed experimentally that enhancement of coal reactivity when micronized in a high-impact disintegrator mill makes it possible to attain self-igniting and self-sustaining (autothermal) compact-flame combustion in a cold environment. But with intensive grinding of coal, the mineral part of the fuel is also being converted, which can lead to both a decrease and an increase in the intensity of the formation of deposits. The effect of grinding on the mineral matter of coal and the formation of deposits in a 5 MW pilot-scale combustor are presented. The experiments showed a decrease in the intensity of formation of deposits after grinding of coal by disintegrating mill as compared to grinding in the ball-tube mill.
Viscosity and acoustic parameters of suspension based on ethylene glycol with aluminum nanoparticles
Authors: Pryazhnikov M I , Minakov A V , Rudyak V Ya , Platonov D V 
Published: July 2020

Abstract
The study of suspensions with aluminum nanoparticles was carried out. Ethylene glycol was used as the base fluid. The mass concentration of Al nanoparticles varied from 2.5 to 20%. The viscosity coefficient of the suspension at different shear rates was measured. The dependence of the viscosity on the concentration of Al nanoparticles in ethylene glycol was obtained. The attenuation of the suspensions was measured. The dependence of the sound speed in suspension on the nanoparticle concentration was obtained. The acoustic parameters of the suspension, such as adiabatic compressibility, acoustic impedance, intermolecular free length, viscous relaxation time, are calculated.
Numerical and experimental investigation of high temperature steam oxidation of molybdenum cladding specimens applied to accident tolerant fuel
Authors: Bazyuk S S , Kuzma-Kichta Yu A , Parshin N Ya , Polunin K K , Soldatkin D M 
Published: July 2020

Abstract
The results of high temperature steam oxidation tests of cladding specimens made of VCPM at nominal test temperature of 1200 °C and exposure duration of up to 8.5 hours at GASPAR facility are presented. The experimental data were obtained by the steam-molybdenum reaction rate constant in the range of steam mass rates from 10 to 120 mg/s and compared with the calculation results of oxidation process taking into consideration the kinetic and diffusion mechanism.
Compressibility effect on heat transfer intensified by horseshoe vortex structures in turbulent flow past a blunt-body and plate junction
Authors: Kolesnik E V , Smirnovsky A A , Smirnov E M 
Published: July 2020

Abstract
Results of numerical simulation of turbulent heat and mass transfer in the 3D problem of flow past a blunt-body and plate junction are presented. Comparison with the known experimental data is given; solution grid sensitivity is discussed. Numerical solutions obtained for incompressible fluid flows with different Prandtl numbers, and for the compressible gas flow with the Mach number ranging from 0.01 to 0.5 are analyzed. The effect of compressibility on heat transfer intensification in the region occupied by horseshoe-shaped vortex structures is investigated.
Experience in using a synthetic turbulence generator for eddy-resolving simulation of the free convection boundary layer on a vertical plate
Authors: Kolesnik E V , Smirnovsky A A , Tschur N A , Ivanov N G , Smirnov E M 
Published: July 2020

Abstract
The paper presents results of eddy-resolving numerical simulation of the turbulent free convection boundary layer that develops along a vertical isothermally heated plate. The problem of definition of boundary conditions at the computational domain inlet, where a time-varying flow field has to be specified, is considered. Mean characteristics of inflow are defined from results of RANS simulation of a 2D boundary layer, and a synthetic turbulence generator is used to introduce unsteady fluctuations at the inlet. Calculations are performed with an in-house unstructured finite-volume code; results of comparison with known experimental data are presented. The influence of the choice of the turbulence model used for RANS-based calculations of the mean inlet flow profiles is considered.
Rebound effects may jeopardize the resource savings of circular consumption: evidence from household material footprints
Authors: Ottelin Juudit , Cetinay Hale , Behrens Paul 
Published: July 2020

Abstract
The circular economy model aims to reduce the consumption of virgin materials by increasing the time materials remain in use while transitioning economic activities to sectors with lower material intensities. Circular economy concepts have largely been focussed on the role of businesses and institutions, yet consumer changes can have a large impact. In a more circular economy consumers often become users—they purchase access to goods and services rather than physical products. Other consumer engagement includes purchasing renewable energy, recycling and using repair and maintenance services etc. However, there are few studies on whether consumers actually make these sorts of consumption choices at large scale, and what impacts arise from these choices on life-cycle material consumption. Here we examine what types of households exhibit circular consumption habits, and whether such habits are reflected in their material footprints. We link the Eurostat Household Budget Survey 2010 with a global input-output model and assess the material footprints of 189 800 households across 24 European countries, making the results highly generalizable in the European context. Our results reveal that different types of households (young, seniors, families etc) adopt different circular features in their consumption behaviour. Furthermore, we show that due to rebound effects, the circular consumption habits investigated have a weak connection to total material footprint. Our findings highlight the limitations of circular consumption in today’s economic systems, and the need for stronger policy incentives, such as shifting taxation from renewable resources and labour to non-renewable resources.
Evaluation for p-y Method for Offshore Large Diameter Monopile in Sand
Authors: Xu Chengshun , Sun Yilong , Xi Renqiang , Sun Yanguo 
Published: July 2020

Abstract
Large monopile is widely used in offshore wind farm due to their relatively simple installation. Monopiles are customarily designed by applying the p-y method. That being said, there is no detailed and uniform interpretation on the reasons for limitations in the current p-y method. An elaborate study is performed to determine the main reasons of such limitations. In this study, a FLAC3D model is presented to evaluate the current p-y method for piles in sand of three different relative densities under a static load, in which the non-linear modulus is taken into account. The results show that the initial stiffness of the p-y method is overestimated and even more magnified in the large depth. The diameter effect should be taken into account under diameters exceeding 3m in loose and medium sand, as well as diameters more than 5m in dense sand.
Influence of the PTO System on the Power of Wave Energy Generator
Authors: Wan Zhanhong , Song Tianyu , Zheng Honghao 
Published: July 2020

Abstract
Nowadays the global demand for energy is growing rapidly, it is highly urgent to conduct the research and develop the efficient renewable wave energy equipment, wave energy converter (WEC). This paper introduces the PTO (Power Take-Off) system and theory of wave energy generators, which shows that the hydraulic system can transfer energy well. We found the relationship between the pendulum length and the wavelength of the floating pendulum wave energy generator and the relationship between the pendulum height and the wavelength. Through the influence of PTO on the power of different wave periods, the power increases first a then decreases with the increase of PTO and we also found the optimal PTO of different wave periods.
Study on the Characteristics of Tides and Storm Surge in Dongji Islands
Authors: Zhao Junyi , Zhao Xinyu , Yao Yanming , Yuan Jinxiong 
Published: July 2020

Abstract
Storm surge has posed a great threat to the safe development of marine ranch in Dongji Islands. Research on the tidal dynamics and storm surge of Dongji Islands is more and more urgent. For this reason, based on measured data of tidal level in 2012, this paper conducts research on the variations of tidal level and storm surge in Dongji Islands. Main conclusions are: Affected by the topography and tidal waves in the East China Sea, temporal and spatial distribution of tidal level and storm surge is asymmetric. Tidal intensity is strong in the eastern sea and weak in the western. The amplitudes of main semi-diurnal tides (M2, S2, N2) in the western sea have a significant attenuation, with the average tidal range decreased by about 16%. Cycle of the practical storm surge is consistent with the tidal constituents, for the cycle at Daishan station was close to 24 h, while Miaozihu station was about 12 h.
3-D inversion of gravity data to determine the Tulehu geothermal prospect zone, Maluku
Authors: Sulistyo A , Daud Y , Latuconsina N , Yunus F M , Kurniawan A 
Published: July 2020

Abstract
The Gravity method is a geophysical method that is widely used for geothermal exploration. The use of gravity data is commonly limited to interpretation of geological structure using 2-D modeling. In this study, 3-D inversion of gravity data conducted to improve 3-D conceptual model of geothermal system. This method was applied in Tulehu geothermal prospect area, which is located in Maluku Province. In 2019, gravity survey was conducted for geothermal exploration in Tulehu by gridding measurement of 130 stations with 500 m spacing. The geological condition of the area is dominated by quaternary volcanic rocks, limestone, alluvial, and metamorphic rocks. The result of CBA and residual gravity indicate the existence of medium gravity anomaly at the Mt. Eriwakang, the high gravity anomalies are found around several structures obtained from Remote Sensing. In the section of gravity 3-D inversion, it shows that the low-density contrast can be seen at 2000–3500 meter and 4500–7000 meter, while high density contrast can be seen at 0–5000 meters and 6500–8000 meters. The low and high-density contrast is associated with the presence of Huwe Fault, Banda Fault, and Banda Hatuasa Fault in the prospect area which is correlated to the geological condition. 2-D forward modeling has a good correlation to confirm the results of 3-D inversion of gravity data.
Remote sensing of tropical forest biomass: The Malaysian experiences
Authors: Hasmadi I Mohd , Pakhriazad H Z 
Published: July 2020

Abstract
The role of forests as potential sinks of atmospheric carbon has been studied across varying scales. In 2017, Malaysia with a total of 52 % her land is covered by tropical forest is very important not only as a source of national revenues but also as environmental protection and conservation areas. In Malaysia attempts to estimate the Above-Ground Biomass (AGB) biomass density of different forest types have been made actively as an action to meet the UN Framework Convention on Climate Change (UNFCCC). Remote sensing is a constantly evolving technology being regularly introduced where high-resolution space-borne and air-borne satellite data have provided an opportunity to better estimate and map AGB across different spatial and temporal scales. The quantification, mapping, and monitoring of biomass are now central issues due to the importance of biomass as a renewable energy source. However, the estimation of biomass is a challenging task, especially in areas with complex stands and varying environmental conditions. Remote sensing offers the technology to enable rapid assessment of biomass over large areas relatively quickly and at a low cost. This paper highlights a review of tropical forest biomass assessment techniques using remote sensing with special emphasis in Malaysia. The successful studies and key work that has been undertaken has been discussed.