Journal of Siberian Federal University: Engineering & Technologies最新文献

{"title":"An Application of CO₂ as a Refrigerant for Medium Temperature Heat Pumps","authors":"V. Karnaukh","doi":"10.17516/1999-494x-0344","DOIUrl":"https://doi.org/10.17516/1999-494x-0344","url":null,"abstract":"This paper presents the energetic and exergetic analysis of a transcritical carbon dioxide based heat pump cycle for heating. Recycled water (tw=25…40 °C) of food production enterprises is taken into account as a source of low potential heat. The theoretical and real CO₂ trans-critical cycles were analysed. Parameters, which characterize cycles from energy and exergy point of view were obtained. The exergy flow diagram (Grassmann diagram) shows that all the components except the internal heat exchanger contribute significantly to the irreversibilities of the system","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"138 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76022238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermogravimetric Analysis of the Combustion of Khakassia Coal, Pine Sawdust and their Blends","authors":"A. V. Zhuikov, A. Matiushenko, P. N. Kuznetsov, O. P. Stebeleva, A. Samoilo","doi":"10.17516/1999-494x-0338","DOIUrl":"https://doi.org/10.17516/1999-494x-0338","url":null,"abstract":"A thermogravimetric analysis (TGA) of the combustion of two long-flame hard coals from the Republic of Khakassia, pine sawdust and their blends in the air stream, depending on the chemical composition and thermal characteristics of the samples, was carried out. The ignition temperature and the burn-out temperature of the coke residue of the studied samples were determined by extrapolation using the TG and DTG curves. The indices of ignition, burnout and combustion are calculated taking into account the time parameters. The ignition temperature of pine sawdust was Ti = 308 °C, the burnout temperature was Tb = 490 °C. When sawdust was added to the coals, the combustion process of the blend shifted to lower temperatures, and the ignition temperature decreased by more than 100 °C compared to the ignition temperature of the coals. The energy -efficient compositions of blends that ensure their high combustion characteristics are determined","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87536635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Studies of Creep of Unidirectional Composite Material of Composite Overwrapped Pressure Vessel","authors":"N. V. Eremin, E. Moskvichev, K. A. Pasechnik","doi":"10.17516/1999-494x-0354","DOIUrl":"https://doi.org/10.17516/1999-494x-0354","url":null,"abstract":"Experimental studies of creep of a composite material of a composite overwrapped pressure vessel are presented. Composite material was an unidirectional tape based on IMS60 carbon fibers and epoxy resin. Creep tests were carried out at various loads and temperatures, taking into account the stress level in structure and measured glass transition temperature of the material. For testing, special equipment was used to install specimens in the grips of the testing machine. According to the test results, the creep curves were obtained. Creep curves according to Findlay's model are presented. For the stage of steady-state creep, the variation of the creep rate at different temperatures were determined, and the average value of the creep rate was calculated for all tested specimens. The results of the obtained data can be used in numerical models for predicting strains of a composite overwrapped pressure vessel under creep conditions","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83175886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Autocompensation of Reactive Power in Electric Networks","authors":"V. D. Pavlov","doi":"10.17516/1999-494x-0342","DOIUrl":"https://doi.org/10.17516/1999-494x-0342","url":null,"abstract":"The aim of this work is to assess the influence of a cascade of transformers and shunt reactors on the reactive power in the network at a symmetrical load. It has been established that any phase is a source of reactive power for the other two phases. Conversely, any two phases are the source of the third phase reactive power. Thus, with a symmetrical load, self--compensation of reactive power occurs. A cascade of transformers is represented by their simplified equivalent circuits (excluding scattering). If the transformers are identical, then the reactive power flow from the load is divided between them into equal parts. Therefore, the reactive power flow in the outer section is three times less than in the inner section. In accordance with this, in a real network, with an increase in the number of transformer substations and shunt reactors, the reactive power flow significantly decreases with distance from the load","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"111 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80659466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-Dimensional Model of Heat and Mass Transfer in Closed-Type Cryogenic Gasifiers","authors":"S. V. Borodkin, I. Bataronov, A. Ivanov, V. Ryazhskikh","doi":"10.17516/1999-494x-0315","DOIUrl":"https://doi.org/10.17516/1999-494x-0315","url":null,"abstract":"A one-dimensional energy transfer equation is formulated in terms of the average mass temperature of a supercritical fluid (SCF), determined by the average mass enthalpy of the flow. The kinetic equation for the heat flow of heat exchange between the SCF and the coolant is used in the form of the Newton-Richman law in the flows of liquid media and thermal resistances for a multilayer heat exchanger tube, taking into account the possibility of icing of the tube from the coolant side. The thickness of the icing layer is found in a self-consistent way when solving the model equations, similar to the Stefan problem. For the proposed model, the thermophysical conditions of heat exchange in the SCF and the coolant are analyzed and the criteria equations for calculating the heat transfer coefficients in the coolant and the environment are selected. The model was tested in various heat exchange schemes","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"211 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88060870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Design of Solar Energy Tracker System","authors":"Oloka Reagan Otieno, M. Abdulhamid","doi":"10.17516/1999-494x-0343","DOIUrl":"https://doi.org/10.17516/1999-494x-0343","url":null,"abstract":"Solar energy is a very important means of renewable energy resource. With solar tracking, it will become possible to generate more energy since the solar panel can maintain a perpendicular profile to the rays of the sun. Even though the initial cost of setting up the tracking system is considerably high, there are cheaper options that have been proposed over time. This paper discusses the design and construction of a prototype for solar tracking system that has a single axis of freedom. Light dependent resistors (LDRs) are used for sunlight detection. The control circuit is based on an ATMega328P microcontroller. It was programmed to detect sunlight via the LDRs before actuating the servo to position the solar panel. The solar panel is positioned where it is able to receive maximum light. As compared to other motors, the servo motors are able to maintain their torque at high speed. They are also more efficient with efficiencies in the range of 80–90 %. Servos can supply roughly twice their rated torque for short periods. They are also quiet and do not vibrate or suffer resonance issues. Performance and characteristics of solar panels are analyzed experimentally","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"107 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77015459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Study of the Influence of the Characteristics of Fuel Injectors on the Ecological Parameters of a Diesel-Generator","authors":"D. Guzei, V. Panteleev, A. Minakov, V. Zhigarev","doi":"10.17516/1999-494x-0353","DOIUrl":"https://doi.org/10.17516/1999-494x-0353","url":null,"abstract":"The paper presents the results of a systematic computational study to optimize the operation of diesel generator fuel injectors. The influence of the diameter of the outlet nozzle of the nozzle and the inclination of its axis, the taper angle of the spray and the injection advance angle on the local and integral characteristics of the operation of the diesel generator, as well as the values of emissions of soot, nitrogen oxides and underburning of fuel, has been investigated. It is shown that even with a slight optimization of the performance of the fuel injectors, it is possible to significantly reduce harmful emissions during the operation of a diesel generator","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74595710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technique of Hydrothermal Power System Balance Calculation with Allowance for the Regime Features of a Hydropower Station Based on the Cost of a Hydraulic Resource","authors":"Yuri I. Sekretarev, Tatiana V. Myatezh","doi":"10.17516/1999-494x-0340","DOIUrl":"https://doi.org/10.17516/1999-494x-0340","url":null,"abstract":"The present paper proposes a universal method for analyzing the efficiency of technical systems using the combination of an optimization method and a method of marginal utility evaluation. At present, the problem of optimal load distribution in the power system between a hydropower plant (HPP) and thermal power plants (TPP) is solved using the equality of the differential incremental rate characteristics of fuel consumption at TPP and water consumption at HPP by the Lagrangian multiplier method. In this case, the number of iterations can be five or more. The proposed approach is based, first of all, on the correct representation of the differential characteristics and calculation of a hydro resource price for the operational control of the HPP. Based on the comparison of water volume at a HPP and fuel amount at combined heat and power plants (CHPP) used for generation of 1 kW power, it is possible to determine a water price for a HPP. Using the examples of Novosibirsk HPP and CHPP, it is expected to develop an estimation of economic effect from the implementation of the developed criteria, the proposed method of determination of a water price at HPP. As a result of implementing the developed method for the HPP, a price of sold electricity in the flexible energy market will be comparable with the price for sold electricity produced at CHPPs, being equal to approximately 12 rubles/kW∙h","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82061065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research of Influence of Substitution of Renewable Energy Sources as a Part of the Scheme of Supply of Own Needs of Small and Micro-HPPS","authors":"A. Achitaev, A. Zhidkov, N. S. Naumkin","doi":"10.17516/1999-494x-0341","DOIUrl":"https://doi.org/10.17516/1999-494x-0341","url":null,"abstract":"One of the directions of modern development of renewable energy technologies in Russia is associated with the expansion of their application as part of the own needs of power plants. This article examines the study of the connection of renewable energy sources (RES) as part of the own needs of micro--hydroelectric power plants. The analysis of possibility of power supply of own needs of micro-HPP by wind power installation with use of the frequency Converter for the purposes of regulation of tension of own needs of station was carried out. The first part of the article is devoted to the analysis of publications on the current problem of the use of small and micro--hydroelectric power plants, as well as the description of the purpose and objectives of the study. The second section of the article presents mathematical models describing the connection of the wind turbine with a frequency Converter to work together with consumers of the station's own needs, for which the function of voltage regulation in the network is supposed to be performed. The law was formulated and an algorithm was constructed for the operation of the wind turbine with a load as part of the station's own needs. Note that this algorithm assumes continuous operation of the wind turbine without switching it according to the scheme of automatic reserve input, which leads to an increase in the installed capacity utilization factor. In the third part of the article the oscillograms of transient processes in the mode with and without wind turbines are considered. The short-circuit mode on the load and the influence of the wind turbine on the value of the recharge current are also considered. And in conclusion, the main conclusions on this work are formulated","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84348983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Chemically Modified Ultra-High Molecular Weight Polyethylene on the Properties of Butadiene Nitrile Rubber","authors":"N. V. Shadrinov, V. D. Gogolev, T. Isakova","doi":"10.17516/1999-494x-0323","DOIUrl":"https://doi.org/10.17516/1999-494x-0323","url":null,"abstract":"For the manufacture of frost-resistant oil and petrol-resistant rubber products, one of the most widely used rubbers is nitrile-butadiene rubber (NBR) with a low acrylonitrile content of 17–20 %. However, the technical properties of its vulcanizates do not always meet all high performance requirements. Therefore, the study of the possibility of improving the technical characteristics of vulcanizates based on frost-resistant NBR is an urgent task. This paper presents the results of studying nitrile-butadiene rubber BNKS‑18AMN filled with ultra-high molecular weight polyethylene (UHMWPE). A feature of this work is the study of the possibility of increasing the technical properties of the obtained elastomeric composites by increasing the interaction between chemically inert UHMWPE and BNKS‑18AMN using the chemical modification of UHMWPE. The modification of UHMWPE was carried out by chemical etching in a solution of chromic acid for 3 and 20 hours. A complex of laboratory studies of the obtained samples was carried out. The influence of the duration of chemical etching of UHMWPE on the rheological and vulcanization properties has been studied on the analyzer of the processing of rubber. It is shown that the filling of UHMWPE into BNKS‑18AMN, in general, leads to an increase in the viscosity of the rubber compound. Chemical etching of UHMWPE leads to a decrease in the rate of vulcanization and the density of the three-dimensional spatial structure of the vulcanizate. The study of the physical and mechanical properties in tension, wear resistance during abrasion and swelling in standard hydrocarbon liquid for testing rubbers SZR‑3 showed that chemical etching of UHMWPE leads to a decrease in strength characteristics, but at the same time leads to an increase in resistance to abrasion and has no significant effect on swelling. The study of changes in the properties of samples after heat exposure showed that chemical etching of UHMWPE significantly reduces the resistance to thermal oxidative destruction in the presence of atmospheric oxygen, but does not affect the resistance to thermal aging in the SZR‑3 hydrocarbon environment","PeriodicalId":17206,"journal":{"name":"Journal of Siberian Federal University: Engineering & Technologies","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75816690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}