Model for evaluation of technical and economic indicators of offshore wind farms

THE PURPOSE. An urgent problem in the development of offshore wind energy is the high cost of generating electricity, which is due to large capital investments. The solution to this problem is possible by increasing efficiency while reducing costs as much as possible, which requires optimal design of offshore wind farms.GOAL. Development of model for the technical and economic indicators of offshore wind farms based on configuration data, taking into account the factors of climatic conditions and the topography of the seabed at the site of the planned wind farm location.METHODS. Mathematical modeling using Matlab software environment.RESULTS. The model evaluates the impact of wake and electrical losses in the main components of the electrical system on the operation of an offshore wind farm, and also allows to take into account the influence of the seabed relief on the economic characteristics of wind turbine foundations. The model was tested on the example of calculating two existing offshore wind farms «Horns Rev 1» and «Horn Rev 2» by comparing the calculated indicators of the average annual electricity generation, capacity factor, capital expenditures and normalized cost of electricity with the actual indicators obtained during their operation. The comparison results show slight deviations within 5% of the actual values.CONCLUSION. The model for assessing the technical and economic indicators of offshore wind farms was developed and tested on the basis of data on the wind farm configuration and layout, as well as factors of climatic conditions and terrain. Evaluation of the computational speed showed a sufficiently high efficiency of the algorithm, which allows the model to be applied to optimize large offshore wind farms.

Implementation of the optimal construction of a combination device and evaluation of reliability by output voltage

The theoretical propositions of the algebra of logic are considered. It is noted that the current microcircuitry based on the algebra of logic contains logical statements: true (yes) is a logical unit, false (no) is a logical zero. Based on the given logical function: ((ABC)×D + A×(BCD) + A×(BC)×D + (AB)×(CD), frontal, minimal, transformed minimal variants of the combination device are implemented, as well as minimized variants in the bases "AND-NOT" and "OR-NOT". A combination device based on import-substituting chips of 155, 176 series has been designed. The analysis of the obtained devices is made from the standpoint of technical and economic indicators, in particular, an assessment of the number of logic elements used, an assessment of the symmetry of the structure, as a result, a reduction in energy consumption, an increase in performance, improvements in parameters for reliability of functioning, a decrease in weight and size characteristics. Assuming that the law of change of the information parameter U1 is close to linear, taking into account the effect of temperature as boundary values for the elements of the applied microcircuits, taking the values -60 °C and +120°. Accordingly, the parametric reliability of the optimal implementation of the device according to the output voltage parameter is calculated. The conclusion is made about the inverse dependence of parametric reliability on temperature growth. A recommendation is given when evaluating parametric reliability for a number of other information parameters about the need to take into account both the number of chips used and the type of their interconnections.

Smelting options for carbon ferrochrome based on ore raw materials, middlings and their technological evaluation

The article presents the results of large-scale laboratory tests carried out in the conditions of the Chemical and Metallurgical Institute named after V.I. Zh. Abishev on the use of briquetted mono-charge in the smelting of carbon ferrochrome on a 250 kVA furnace. The purpose of these studies was to determine the technological parameters of the use of briquetted mono-charge containing in its composition chrome ore, wastes from the production of high-carbon ferrochrome, middlings and various carbonaceous reducing agents. The main idea of using these briquettes was to multiply the contact surface of the reductant and ore, which should speed up the technological process. The principal possibility of smelting a standard alloy using briquetted mono-charge is shown. The alloy for individual charge options meets the requirements of the standards. In comparison with the technology without the use of briquettes, the mono-charge technology has shown advantages in all main parameters. The technology with the use of briquettes from the dust of the AktZF gas cleaning system is distinguished by a low yield of non-standard metal and slag, the bulk of the material goes into the gas collection system. Technologies from briquettes from fines pellet production area of Donskoy ore mining and processing plant and flash have very low specific technical and economic indicators and cannot be recommended for industrial use. Improvement of briquetting modes and technology of their smelting is required. The technical and economic indicators were higher than the current one, showed briquettes from ore and coke of the People's Republic of China, briquettes of ore from borlin and shubarkol coals of Kazakhstan.

REMOVAL OF TECHNICAL AND ECONOMIC INDICATORS OF THE D-240 ENGINE WHEN USING BIOFUELS BY APPLYING THE DIESEL-RK SOFTWARE COMPLEX

Ukraine is one of the energy-deficient countries because it covers its needs in fuel and energy resources from domestic reserves by only 53% (imports 75% of the required natural gas and 85% of crude oil and petroleum products). Dependence on oil imports is seen by most developed countries as a matter of national and energy security, and the use of petroleum products as energy sources poses a significant environmental risk. According to the analysis of the state of the world engine industry, the most effective measures to improve the design of the engine are: development and implementation of a new workflow with effective methods of mixing and combustion; development and creation of the design of the system of automatic regulation of diesel rotation. frequency to improve fuel economy And to reduce toxicity in partial load mode, some cylinders are switched off at idle. To strengthen the requirements for fuel consumption standards and the level of toxicity of exhaust gases, as well as to increase the reliability and efficiency of agricultural power engines, it is necessary to formulate measures to improve its design. The choice of a fuel should be determined by the optimal combination of environmental and economic performance of the engine. Prospects for the use of a particular fuel of plant origin are noted. If for fuels of petroleum origin the improvement of its properties is determined by special processing, then oils with the set characteristics can be received already in "field" by selection of the corresponding grades of plants, use of fertilizers, agronomic actions, etc. The problem of reducing the consumption of diesel fuel at idle and low load can be solved by excluding from its operation part of the cylinders (this method is widely used) and closing the cycle of one cylinder. A comparative analysis of the main technical and environmental performance of the D-240 diesel engine when working on traditional and alternative fuels using the computer program Diesel-RK.

Technical and economic calculation of a solar-powered charging station for electric vehicles

Problem. Development and implementation of green technologies is both an urgent and a cost-effective scientific and engineering task. Therefore, the issues related to the study of renewable energy sources, which are used as the main sources of energy for electric vehicles, are quite relevant and promising. At the same time, an equally important question is how profitable is building solar charging stations in terms of both ecology and economy. Goal. The aim is calculation and analysis of technical and economic indicators of a solar charging station for electric vehicles (EV). Methodology. The analytical methods of studying the development and application of the ways and devices to transform the energy of the sun into electricity are used, as well as the methods of experimental research and mathematical methods of processing and modulation of the received results; methods of calculating technical and economic indicators. Results. The review of the literature on the development of renewable energy sources, in particular, solar power plants, and the spread of electric vehicles with the gradual displacement (replacement) of traditional cars working on internal combustion engines with electric vehicles (BEV and PHEV) was made. The main parameters and technical characteristics of the solar-powered charging station (SPCS) were studied. For the analysis and calculation of technical and economic indicators of SPCS for EV it is offered to take a SPP with a capacity of 20 kW as a basis. The calculation of SPCS electricity generation both for own consumption and for power supply of EV and the sale of surplus electricity to the general network at the “green tariff” was carried out. Originality. The technical and economic calculation of SCS was made taking into account the rise of electricity prices in Kharkiv region (Ukraine). Practical value. According to the analysis of the obtained results, it can be said that the payback period of SPCS for EV is about 7.9 years. If we consider the constant increase in the cost of electricity (approximately 15% per year), we can expect the payback after 6.8 years of operation.

STUDY OF PERFORMANCE INDICATORS OF TRANSPORT MACHINE-BUILDING AND RAILWAY INDUSTRY ENTERPRISES IN A PANDEMIC CONDITION COVID-19

The article analyzes the impact of the consequences of the quarantine measures introduction to counter the pandemic COVID-19 on the economy of Ukraine in general and the domestic transport machine-building sector in particular. It has been established that one of the most affected sectors of the economy is transport and mechanical engineering, in particular the railway transport sector. It is determined that at present a very relevant issue for the further development of domestic enterprises of transport machine-building and railway industry is the assessment of the impact of the COVID-19 pandemic on the activities and financial and economic performance of these enterprises. The financial and economic indicators of such domestic enterprises of transport machine-building and railway industry, such as JSC "Ukrzaliznytsia", PJSC "KVBZ", SE "UkrNDIV", LLC "LEMTRANS" and LLC "KERNEL-TRADE", TDV "Popasnyansky Car Repair Plant" are analyzed. It was determined that the most affected of the studied domestic enterprises under the conditions of quarantine measures were JSC "Ukrzaliznytsia", PJSC "KVBZ", TDV "Popasnyansky Car Repair Plant". The main reasons for the decrease in technical and economic indicators at domestic enterprises of transport machine-building and the railway industry are studied by the method of expert evaluation. According to the analysis of expert evaluation data, the most important reason for the deterioration of technical and economic indicators of enterprises is the lack of state support and incentives for the development of transport machine-building and the railway industry in the country (19.6%). Experts estimate the impact of the consequences of the introduction of quarantine measures to counter the COVID-19 pandemic at 8.1%. Measures are proposed to improve the technical and economic performance of the most affected domestic enterprises of the transport machine-building and railway industries in the context of the COVID-19 pandemic.

Technical indicators of modern trawlers

The article identifies the problem of the lack of up-to-date publicly available statistical information on the technical and economic performance of modern fishing vessels, including foreign mining vessels, which entails serious restrictions on the choice of a prototype, from which domestic authors are forced to use outdated indicators of ship designs built in the second half of the XX century. The methods of obtaining the necessary information using the open databases of the Global Fishing Watch organization are presented. The methods of the organization's work with information and the characteristics of some databases are described. The data has been processed for further use. According to one of the fishing criteria, the most effective trawlers of 2020 were selected. Thanks to the obtained statistics on the operation of trawlers, it was possible to obtain many technical indicators of the vessels ' operation: the operating mode, the structure and duration of the fishing voyage, the form of fishing organization, the balance of calendar time. As the statistics are processed, the results are analyzed. The observations made are described: about the round-the-clock operation mode; about the duration of storming; about the associated fishing. The obtained indicators were compared with the indicators of trawler factories in 1969. The necessity of continuing the study of the main technical and economic indicators of modern fishing vessels: income, expenses, profit is justified.

ENERGY EFFICIENT EQUIPMENT FOR MODERNIZATION OF THE GAS BOILERS POWER 0.1-30 MW

The possibility of modernization of boilers TVH-8M, TVH-8 and NYYSTU-5, operated in Ukraine, with the increasing of their technical and economic indicators to the modern European level is shown. Projects of modernization of boilers have been developed, which consist in redesign of heating surfaces in convective shafts of existing boilers without increasing their overall dimensions with using convective part of pipes diameter 32 x 3 mm and replacement of burner devices by developed new type MPIG-3. It is shown that the results of industrial implementations achieved efficiency of boilers type TVH-8M (TVH-8) 94-96% in the operating range of their load and obtained the calculated efficiency for boilers NYYSTU-5 92-94%. It is experimentally proven that when installing special calibrated nozzle, instead of drilled holes in the collectors of gas burners, it is possible to keep the nozzle geometry (natural gas burner consumption depending on pressure) unchanged throughout the service life. The technical possibility of combustion of biogas and mixtures of natural gas and hydrogen in the slot bottom diffusion burners of the MPIG-3 type, when replacing only the nozzle apparatus is shown. Bibl. 17, Fig. 6, Table 1.

OPTIMAL CONSTRUCTION AND TECHNOLOGICAL SOLUTION FOR RECONSTRUCTION OF A CITY PIPELINE AND THE RESULTS OF ITS TESTS

Purpose. To once again draw the attention of bridge owners and bridge experts to the problems of reconstruction of long-term bridges and on a concrete example of reconstruction of a rather problematic city overpass operated for more than 60 years to shows that with the optimal structural and technological solutions of the reconstruction received a restored bridge, and its operational and technical and economic indicators which according to the requirements of the National Building Norms completely correspond to the new bridge, but the reconstruction cost and the lead time are greatly reduced. Methodology. To achieve this purpose over the past ten years of operation of the overpass conducted three inspections and full-scale static tests. It is determined that most of the existing reinforced concrete structures, although defective and in need of repair, can be used for further operation after reconstruction, provided they are reinforced. Worn out non-repairable structures that needed to be replaced were also found. Results. According to these initial data, a reconstruction project was developed using scientific and technological structure developments of the Branch Research Laboratory 88 of Lviv Polytechnic National University for the reconstruction of bridges. The span structure has been expanded to 4 lanes from the size G-10.5 + 2 × 0.9 m to the new G-16.5 + 2 × 1.5 m in a combined way – symmetrical completion of two new beams with their support on the extended support and installation of a reinforced concrete extension board with cantilever overhangs 2.7 m long. The most damaged boundary beams were replaced with new ones, designed for normalized temporary loads A15 and NK-100. For further operation the other existing beams are reinforced in one of the least expensive ways – by changing the static scheme from the existing split to the new clamped on the supports frame-inseparable. A set of repair works is provided to ensure the normalized durability of the reconstructed overpass. The scientific novelty is to develop a method for determining the experimental Coefficients of Transverse Distribution of Bending Moments (CTDM) and external loads (CTD) based on the results of tests of the span structure. The possibility of applying the method of elastic supports for the spatial calculation of span structures with beams of different stiffness is confirmed. Practical significance. The use of optimal design solutions for the reconstruction of existing span structures: reinforced concrete billboard with large cantilever overhangs to expand and change the static scheme to strengthen the beams of span structures.

Complex feed additive for broiler fattening of ducklings

The purpose of the research is to develop an effective feed additive with an optimal content of raw protein in combination with flavoring additives for ducklings, which allows to increase zoo technical and economic indicators with broiler technology of fattening young animals. Research methods. A scientific and production experiment was conducted on three groups of analog ducklings from a daily age to 49 days old. The studied indicators are: the dynamics of live weight by fattening phases, absolute and average daily growth, the safety of young animals, feed conversion, slaughter indicators, the European fattening efficiency indicator, the profitability of meat production. Results. The use of compound feeds with an optimal level of protein content in combination with flavoring additives prepared on the basis of developed feed additives intended for fattening broiler ducklings in the fattening phases contributes to an increase in: live weight by 11.4 %, the safety of young animals by 3 %, feed consumption and conversion by 3.9 and 7.6 %, slaughter yield of 1.1 %, the European fattening efficiency indicator from 246 to 308 units and the profitability of meat production by 24.5 %. Scientific novelty. For the first time, a complex feed additive has been developed, which, according to the age periods of fattening, includes three varieties: “Prestart”, intended for intensive fattening of young animals from daily to 10 days of age inclusive, “Start” for ducklings from 11 to 21 days and “Finish” from 22 to 49 days. The rate of introduction of the additive is 30 % of the mass of mixed feed. The composition of the supplement includes high-protein feeds, premixes, amino acids and flavoring substances (monosodium glutamate, acetic and citric acids, a mixture of phytogenics: oregano, cinnamon, red pepper).