bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioturbation enhances the removal of petroleum hydrocarbons in sediments by bacteria
Authors: Zhao Wenbo , Yan Bo , Zhang Xin , Liu Xianbin 
Published: April 2020

Abstract
A labortatory experiment was designed to study the removal of total petroleum hydrocarbons (TPH) by bacteria-bioturbation in the sediments. TPH were detected on 0, 5, 10, 14, 17, 20, 24 d in different phases and the removal rate in different layers of TPH in sediments was measured. The results showed that there were three results about the fate of TPH in the sediments: transfering to seawater by bioturbation; accumulating in the worms by feeding and degrading by bacteria. The removal rate of TPH in joint repairing group (JRG) was obviously higher than other three groups and reached to 86.01%, 83.58% and 75.56% in upper, middle and lower layers, respectively. The concentration of TPH increased 2.9264 mg/L in seawater and 12.7514 mg/kg in worms, imply that feeding by worms is an effective way to remove TPH in the sediments. The result of orthogonal experiment in the laboratory demonstrated that the best conditions to remove TPH by bacteria-bioturbation is: A. density of worms, 200 ind/m2; B.volume of bacterial fluid vaccination, 25 mL; C. salinity of seawater, 23; D. pH of seawater, 8.5; E. cultivation time, 12 d.
Policy analysis and technical evaluation index of multi-energy complementary projects in China
Authors: Li Yongtian , Zhang Huan , Xiu Kehua , Li Jiao , Li Hai 
Published: April 2020

Abstract
Multi-energy complementary renewable energy system is an efficient energy supply system based on thermoelectric-gas-storage coupling technology to realize full renewable energy supply in local regions, with biomass power generation as the basic energy, wind, light and storage as the supplement. Since 2000, China has promulgated a series of policies related to multi-energy complementarity to promote energy reform and renewable energy development. China supports the construction of multi-energy complementarity, micro-grid and renewable energy projects. By optimizing the process route of “source-network-load-storage” and adopting chain and vertical integrated feedback as auxiliary technical measures, the deficiencies of renewable energy projects in energy production, storage, transportation, conversion, use and recovery can be complete. Intelligent dispatch through “end-pipe-cloud” integrated energy management platform can compensate the characteristics of non-flexible operation, uncertainty and volatility of renewable energy. According to the characteristics of renewable energy in multi-energy complementary projects, technical evaluation index, economic evaluation index and social benefit index are established, and the advantages and disadvantages of renewable energy projects are evaluated by multi-dimensional indicators.
An experimental investigation on the transient heat transfer characteristics using air/water droplets two-phase flow
Authors: Abed A H , Shcheklein S E , Pakhaluev V M 
Published: April 2020

Abstract
The present study focused on evaluating the heat transfer behavior and predicting the surface resulting status during air/water droplets two-phase flow. Transient heat transfer based on the lumped capacitance model (LCM) was investigated experimentally under a range of water droplets concentration, surface temperature, and varying Re number. Compared with a single-phase air cooling, the transient surface temperature decreased with the increase in water droplets concentration and Re number. At the same cooling time, the surface temperature decreases about 13.5%, 47%, and 53.2% for (j = 46.79 – 111.68 kg/m2 hr). It was also noticed that the heat transfer coefficient increased with the increase in water droplets concentration and reach its maximum value at (j = 111.68 kg/m2 hr). Based on the analysis of the experimental results, the heat transfer mechanism due to the impacting of water droplets on the sphere surface was classified into three important physical regimes. Clear convection heat transfer regime corresponds to the dry region (region I); Convection and evaporation regimes correspond to the dry-out and wet regions (region II and III).
Numerical and Experimental Investigation of heat transfer and flow structures around three heated spheres in tandem arrangement
Authors: Abed A H , Shcheklein S E , Pakhaluev V M 
Published: April 2020

Abstract
The objective of this work is to evaluate the convective heat transfer and flow characteristics around three heated spheres in a tandem arrangement. Numerical simulation and Experimental verification were performed using stationary copper spheres located inside a cylindrical channel with constant channel-to-sphere diameter ratio. Numerical simulation is done for three-dimensional steady-state flow using ANSYS-FLUENT by solving the Reynolds-Averaged Navier Stokes (RANS) equations. Over the test range of Reynolds numbers (2500-55000), the numerical results of the average surface temperature and heat transfer coefficient obtained are a reasonably good agreement with those obtained by experimental measurements. The distributions of the heat transfer coefficient, temperature profiles, velocity field and pressure coefficient around the sphere’s surface are calculated and analyzed.
Experimental investigation on the enhancement of heat transfer by using carbon nanotubes CNT taunit m series
Authors: Ali A J , Jaber H J , Habeeb L J , Tugolukov E N 
Published: April 2020

Abstract
The enhancement of heat transfer is considered as one of the important tasks for controlling the energy dissipation and consumption. In order to secure this task, it is intended to increase the efficiency of heat exchanging systems taking into account the economic and environmental considerations. This work aims to test experimentally the effect of nanoparticle concentration functionalized carbon nanotubes (FCNT Taunit M) in water and Reynolds number on the heat transfer coefficient. Three concentrations of 0.01, 0.05, 0.1 vol.% for FCNT taunit have been used. The heat transfer augmentation of the nanofluid was investigated experimentally through a test rig constructed for this purpose under constant heat flux range (16061-22682) W/m2 at the developing region with Reynold number range 5000, 7000 and 9000 have been used. The particle size 12 nm for FCNT Taunit M. The experimental results revealed an augmentation in the Nusselt number as the volume concentration increased. The economic aspect was taken into account in this study. Pressure drop can be neglected because the increases were very small.
Possibility of using associated petroleum gas as a fuel for a production boiler house
Authors: Balzamov D S , Balzamova E Yu , Bronskaya V V , Valitov N V 
Published: April 2020

Abstract
Current legislation of the Russian Federation sets requirements for oil companies for utilization of produced associated petroleum gas (APG) at the level of 95%. Thus limiting its burning in torches in the fields. The most convenient way of APG utilization for oil companies is to pump it back into the reservoir, which sometimes allows to increase oil recovery. APG is also used for commercial generation of electricity and heat in fields by burning in gas turbine and gas-piston installations. Given the cheapness of associated gas in comparison with natural gas (NG), it is promising to replace NG with APG for large production boilers located in the immediate vicinity of the associated petroleum gas pipeline. The article provides a comparative analysis of the parameters of APG and NG, a scheme for preliminary preparation of APG for its subsequent combustion in the boiler room, an analysis of the performance of the boiler house to generate thermal energy, the feasibility of using APG as the main fuel for the production boiler room.
Contribution of heat loss by infiltration to energy saving and microclimate in multi-family residential buildings
Authors: Elistratova Y V , Kireev V M , Seminenko A S 
Published: April 2020

Abstract
The problem of energy performance takes a leading position in world politics today. In the territory of RF a number of regulatory documents have been developed and put in force in construction industry, regulating the activity of design and construction organizations in the field of energy performance, including energy loss issues. The article analyses current methodology of calculating infiltration heat loss in a multi-storey residential building with account of the number of storeys. Calculation results in graphic form have been shown for the determination of infiltration heat loss for a 14-storey typical residential building, and imperfection of the methodology has been shown on the basis of these results. A conclusion has been drawn that infiltration loss calculation using current methodology gives overestimated values leading to unreasonable excess consumption of heat energy, and consequently, to economic losses. The article will be useful for engineers of designers of heating systems, employees of management companies.
Determination of the thermotechnical measures of the condensing water heating boiler’s high-temperature section
Authors: Gubarev A V 
Published: April 2020

Abstract
This paper presents the experimental data processing results, obtained during tests of the fuel-saving condensing water heating boiler, that has been designed by the employees of the Belgorod State Technological University named after V.G. Shukhov. The mentioned boiler can be used in heat supply for residential, industrial and office buildings. The paper presents the justification of the stand-alone systems actuality use for heat supply of consumers with different needs, and also the use of such systems as a heat-generating unit in condensing boiler type as a heat source. It demonstrates the functional diagram and description of the test bench for the condensing water heating boiler specimen with heat production of 250kW, and also gives an operation description of this test bench. The paper presents the heat transfer agent values of flow rates and temperatures, obtained during the boiler’s tests under different loads. It also describes the test result processing methods, presents formulas for calculations. It presents dependences of the energy carrier parameters, and also heat transfer coefficients in the boiler’s high-temperature section elements on its load. The results analysis of the experimental data processing has been conducted. The conclusions about prospective use of the suggested condensing water heating boiler as the heat-generating unit in heat supply stand-alone systems for consumers with different needs have been formulated.
Development of an algorithm for analyzing the causes of increased oxygen content of condensate
Authors: Iglina T V , Popov A I , Krasnova N P , Rakhimova J I , Gorshenin A S 
Published: April 2020

Abstract
To increase the efficiency of condensers, one of the most important methods is to constantly maintain a high hydraulic density, since malfunctions of the condensing unit lead to a significant reduction in electricity generation. The increased air content in the wet vapor in the condenser and the air suction into the turbine, lead to exceeding the standard values of the condensate oxygen content and therefore have a significant impact on the uninterrupted operation of the TPP, causing the pipeline to corrode from the condensation unit to the deaerating unit. In addition, the increased oxygen content makes heat transfer difficult, since an insulating layer is formed between the condensate film on the heated surface and the steam. Currently, there are a number of methods for thermal calculation of a condensation unit. In this work, the most accurate Iglin-Shepelev technique was used. Using the developed algorithm, the work of the Kirov CHPP-4 and Bezymyanskaya CHPP was analyzed. The experimental data with the calculated characteristics plotted on them are also clearly shown at various temperatures of cooling water with an average flow rate of circulating water, and the reasons for the increased oxygen content of the condensing units of the stations under consideration are identified. Based on the calculation results, measures were proposed to eliminate the increased oxygen content.
Use of the PMU Infrastructure to Determine the Location of Short-circuit Power Lines
Authors: Buryanina N , Korolyuk Yu , Koryakina M , Suslov K , Solonina N , Lesnykh E 
Published: April 2020

Abstract
One of the serious problems of the normal operation of power systems is a violation of efficiency of overhead power lines. Short circuits are especially dangerous. The probability of occurrence of faults is reduced, but not reduced to zero, with an increase in the quality of installation, reliability, insulators and conductive materials. The proposed method is based on the fact that the short circuit current at the beginning of the transmission line of power electric system depends on the distance (location) to the fault point. This article discusses the following topics: theoretical possibility of fault location on the time of arrival of the responses to the beginning and end of the line, the development of the algorithm processing of information, the development of the block diagram of additional devices that are not included in the phasor measurement units (PMU). The article gives an example of the application of this technique.
The method of power transformers and autotransformers windings condition determination
Authors: Gayfutdinova E R , Bulatova V M , Ilkevich A R 
Published: April 2020

Abstract
In article advantages and shortcomings of a method of the frequency analysis of a condition of windings of transformers are considered. This control method of a condition of windings of the transformer is based on comparison of the amplitude-frequency characteristics (AFC) of the diagnosed transformer with its amplitude-frequency characteristics in good repair. It is reported that in various frequency ranges it is possible to find manifestations of various defects and bruises of windings of power transformers and autotransformers. Using a pulse frequency analysis method, the amplitude frequency response spectrum is examined in frequency ranges from zero to 2 MHz. Types and places of defects of transformer winding are determined from value and direction of frequency offset of amplitude-frequency characteristic lines. Such types of defects can include changes in the state of windings, violations of the pressing mechanism, displacement of winding turns relative to each other. In order to determine the type and magnitude of the defect, this method creates a mathematical model of the transformer. An important task in the simulation of transformer windings is the connection between strain types and transformer elements.
Electric Grids Technical Evaluation Method based on their Failure Probability
Authors: Kompaneets B S , Boyarkov D A 
Published: April 2020

Abstract
The article provides the substantiation of the necessity to develop a mechanism for determining the electric grid element with the lowest reliability taking into account the equipment operation peculiarities in the Russian Federation. Critical analysis of existing approaches to identifying dilapidated electrical equipment, as well as recommendations of the Ministry of Energy of the Russian Federation on assessing technical condition of electric networks has been carried out. It is proposed to determine the technical condition of electric grids by the value of their failure probability. Failure probabilities mathematical models for large groups of emergency modes are given: insulation failure, failure of current-carrying elements and failure due to mechanical damage, as well as for all electrical equipment on the whole. Criteria and an algorithm for mechanical defects of electric grids elements expert evaluation are presented. The calculation of the failure probabilities for two elements of real electric grid is made. The conclusions is made on the feasibility of replacing one of the considered elements.
Development of an evaluation method for electromechanical systems unification
Authors: Titova L N , Pertsev U A , Samodurova S A , Nuhin P O 
Published: April 2020

Abstract
The paper examines problematic areas of electromechanical systems unification, formulates and presents formal writing of problem for systemic unification of electromechanical systems and its solution procedure, describes general evaluation scheme of technical-and-economic effect from implementation of different variants of electromechanical systems unification. Presents results of the calculation relations that allow to carry out full and thorough formulation of technical specifications with due consideration of possible unification variants that brings out maximum result at the designing and execution project stage, operation and servicing of the electromechanical systems. Method is designed to evaluate values of technicaland-economic outcome from work that is being conducted in the interests of the suggested unification variants implementation for electromechanical system specimens at the development stage. Presented method is the primary way to construct criterial function of system unification problem. Project’s future outlook can be determined at any point of the designing stages with consideration to service life of the product that is being in development, product family, its components, which included in the electromechanical system, as a separate entity and also as a part of an entire system.
Review of technologies for suppressing emissions of benzo(a)pyrene at energy enterprises
Authors: Rikker Yu O , Kobylkin M V 
Published: April 2020

Abstract
Power engineering enterprises have a great impact on the environment. Flue gas emissions contain solid ash particles, sulfur oxides SO2, SO3, nitrogen oxides NOx, carbon monoxide CO (monoxide) CH hydrocarbons; in some cases, there may be a danger of radiation contamination, but the most dangerous substance emitted into the atmosphere is benzo(a)pyrene C20H12, which has a negative effect on human health. Polycyclic aromatic hydrocarbons (PAH), including benzo(a)pyrene contained in flue gas emissions from energy enterprises, have a serious impact on human health. Taking measures to suppress other harmful emissions from thermal power plants (nitrogen oxides and sulfur oxides) can increase the content of benzo(a)pyrene, which poses a serious problem for modern researchers. As part of this study, various technologies for suppressing benzo(a)pyrene emissions at energy enterprises were considered. The main disadvantages of the described methods are highlighted. The possible danger of increasing benzo(a)pyrene emissions when trying to suppress other emissions is noted.
Analysis of the unsteady temperature condition of a building during non-working hours when heating load is decreased
Authors: Svirin M V , Bychikhin S A , Trubaev P A , Seminenko A S 
Published: April 2020

Abstract
This paper examines the issue of fuel and energy resources conservation through the non-working hours heating load decrease. The paper’s objective is the determination of savings when non-working hours heating load is decreased, considering the unsteadiness of the heat transfer processes through the enclosing structures, heating modes determination, which ensure the required microclimate parameters in the building during working hours. The analysis of the unsteady temperature condition has been conducted using systems of differential equations, the heating load decrease method has been suggested with further calculation for the existing building and technical-and-economic evaluation of the suggested energy conservation measure. To solve this problem the mathematical model was constructed, which considers the unsteadi-ness of weather conditions and temperature conditions of the building when the heating load is decreased. The method of heating load decrease was suggested with further savings calculation for the High School № 4 in Belgorod city. The modeling helped to establish that to ensure steady microclimate parameters in the building after period of heating load decrease to 12°C ends, it is necessary to conduct short-duration overheating of the building by increasing inside temperature to 21°C for the period from 5:00 till 9:00, to prevent loss of heat by the enclosing structures. When the room temperature during non-working hours is decreased to 12°C the cal-culated economy is 10%.
The study of ecological impact of fly ash-based geopolymer binders on soil and aquatic biota
Authors: Vasilenko M I , Lebedev M S , Goncharova E N , Kozhukhova N I , Kozhukhova M I 
Published: April 2020

Abstract
Coal power plants represent the large source of environmental pollution in soils, ground and surface water by leaching out toxic compounds from open landfilled and impounded coal combustion residuals (CCR) such as fly ash. The use of fly ash as a main component in geopolymer binder (GB) systems is one of the effective methods of CCR beneficial utilization. The toxicity assessment as well as leachability of harden geopolymers were tested in aqueous media where oat seeds were used as affected test objects. Bio-resistance of the developed geopolymers was evaluated by the resistance to mold fungi growth. The developed geopolymers demonstrated a very low toxicity and leachability to the biota based on the low effect to germinating ability and growth retardation of the exposed oat seeds. Therefore, the studied fly ash products were proved to be environmentally safe when used in GB systems. The absence of fungi growth observed on the surface of geopolymer samples demonstrates high bio-resistance.
Evaluation of the hazardous emissions from different types of RDF combustion in low power boilers
Authors: Kornilova N V , Trubaev P A 
Published: April 2020

Abstract
Content evaluation of the hazardous substance emission from different types of waste combustion in two solid-fuel water heating boilers was carried out. For 100 kW pyrolysis boiler the content in exhaust gases of the following compounds was determined: NO2, NO, CO, CH4, phenol, benzol, SO2, formaldehyde, HCl. For 200 kW stoker grate boiler the content in the exhaust gases of the following compounds was determined: CO, NO2, NH3, mercaptans, H2S, phenol. For the targeted factors, the calculated hazardous substance ground-level concentrations don’t exceed the maximum allowable concentration limit. The hazardous substance emissions in low power boilers are comparable with high power analogs but have lower combustible efficiency. Waste combustion in the pyrolysis boilers creates 2-10 times less hazardous substances than in grate firing. It was established that combustion mode influences only the carbon monoxide content. The content of other hazardous compounds in the exhaust gases doesn’t depend on the combustion parameters. The additive criterion of total emissions was suggested, which presents the sum of the ratio of the calculated ground-level hazardous substance concentrations to maximum allowable concentrations. Unlike the existing dimensionless concentration, the criterion considers hazard class and compound fraction in gases. The highest criterion value of the total emissions was noted during wood waste combustion (windows, doors, furniture) and RDF fuel, which contains a large amount of plastics