• Influence of external mechanical loads on change of electrophysical characteristics of film sensor elements

    pg(s) 121-127

    The materials of the article consider the influence of external mechanical loads of static and dynamic action (pressure force, mechanical impulse, vibration) on the change of electrophysical characteristics (electrical conductivity, specific capacitance) of film sensor elements. It is shown that an increase in the mechanical load on such an element with a simultaneous decrease in the interact ion time with a constant contact area leads to an exponential increase in the power and sensitivity of the reaction pulse, provided that such mechanical load does not exceed the mechanical strength of the sensor element. At the same time, the increase in the mechanical load on the sensor element at constant time and contact area, almost does not change the sensitivity of the reaction pulse (the maximum increase in sensitivity does not exceed 1.8%). In this case, vibrational oscillations in the frequency range 30… 85 Hz at mechanical forces of the order of 20 … 150 mN create response pulses of the order of 12… 45 mV/μs, which are perceived as “false positives” of the sensor elements. A further increase in frequency and mechanical effort leads to the destruction of the base of the sensor element and the detachment of the sensor f ilm from the base. Reducing the frequency and mechanical forces create reaction pulses up to 12 mV/μs, which does not exceed the allowable values of “white noise” (about 25… 35% of the minimum value of the reaction pulse).

  • Technologies for joining dissimilar materials in the automotive industry

    pg(s) 117-120

    The paper presents the results of research aimed at determining the quality of welds in steel and aluminum alloys. Laser welding technology, fusion-pressure welding in combination with adhesive bonding were used for joining. The present research describes a new bonding technology based on the resistance welding process with a combination of adhesive bonding. Its implementation allows the joining of aluminum and steel sheets at extremely short welding times with a high concentration of energy in combination with adhesive bonding. The quality of the joints was determined on the basis of the tensile shear test according to ISO 12996.

  • Improving the Corrosion Resistance of Carbon Steel Cylindrical Pipe by Nano-Materials Coating, Part -1.

    pg(s) 110-116

    Recent research has shown that the Nano coating materials play a vital role in improving performance of corrosion resistance in hostile environment and enhancing the mechanical properties and reducing the dimension changes. Due to the superior capabilities of Nano coating in many benefits which can be achieved, in addition to corrosion resistance, mechanical properties, make it smoother, stronger and improves its adhesive properties. In this work, the effect of anti-corrosive nanomaterials (Cobalt and Zinc) coating on chemical corrosion behavior and mechanical properties of carbon steel cylindrical pipe were studied in detail. The Nano-coating was done with different thicknesses (300nm,600nm,900nm and 10 μm), then analyzed using ANSYS software technology (version .19).The results showed that there is a strong relationship of corrosion improvement with improving mechanical properties, especially surface deformation resistance, elastic strain and stresses reduction of the inner pipe surface which contains a pressurized corrosive fluid. The maximum improvement was with the thickness of the cobalt coating (10 μm. The result of improvement in corrosion resistance of the cobalt-coated surface is approximately (5.165%) compared to the uncoated surface, also, the results showed an improvement in mechanical resistance and corrosion res istance because of deposition of cobalt particles better than zinc particles in all different thicknesses, with a maximum of about (66%) compared to zinc. Therefore, can conclude that the improving corrosion resistance due to coating with nanomaterials is very promising.

  • Studies on bimetallic ingots for armour by the methods of non-destructive testing

    pg(s) 107-109

    We have carried out researches for working out technological electroslag remelting conditions to produce bimetallic ingots. A new plant flow diagram has been developed for the manufacture. Experimental series of melting was performed on a laboratory electroslag remelting installation by developed by us electroslag remelting conditions. Bimetallic ingots for armour were produced of different combinations steel grades. Ingot of X38CrMoV 5 1 (DIN 1.2343; AISI H11) -10G2SF perspective steel grades is investigated. By the method of non-destructive testing the fusion of two steel grades along height of ingot is investigated. Macrostructure of cast transverse templates is investigated. A complete fusion of steels is established.

  • Exergy analysis of base and optimized high pressure feed water heating system from nuclear power plant

    pg(s) 103-106

    In this paper is performed exergy analysis of high pressure feed water heating system and all of its components which operates in nuclear power plant. Four cases are observed: system operation in the base case and system operation in three optimized cases. Exergy analysis show that optimization by using different algorithms has a different influence on the exergy destructions, while all the algorithms increase whole system and its components exergy efficiencies. An increase in the ambient temperature increases exergy destructions and decrease exergy efficiencies of the whole observed system and its components, regardless of operation case. The highest exergy efficiency of the whole analyzed system is 96.12% and is obtained by using an IGSA algorithm at the lowest observed ambient temperature of 5 °C. By observing exergy destructions only, it should be noted that GA and IGSA algorithms give almost identical results.

  • The use of encapsulated sodium ferrate in wastewater treatment in the production of animal feed

    pg(s) 53-55

    The article presents the results of studies devoted to the use of ferrate in wastewater treatment in the production of animal feed. A method of wastewater treatment from various substances is proposed using the example of phenol. The possibility of obtaining of encapsulated sodium ferrate based on hexane, ethylcellulose and paraffin was revealed; its stability in air and in an alkaline solution was established. It has been proven that the reuse of industrial wastewater is a determining direction in preserving the health of animals and birds and the ecological cleanliness of the environment in general.

  • Thermodynamic analysis of a 17.5 MW geothermal power plant operating with binary Organic Rankine Cycle

    pg(s) 49-52

    This article presents the thermodynamic analysis of a 17.5 MW gross electric geothermal power plant based on binary cycle technology with isobutane. The geothermal power plant comprises two separate closed loops: the geothermal fluid flows in one loop and the Organic Rankine Cycle (ORC) fluid flows in the second loop. The geothermal fluid is extracted from a depth of 2500-3000 m with a temperature of 170 °C and a pressure of 25 bar. Two production wells supply geothermal fluid (brine and steam) with a high fraction of noncondensable gases (NCG). A separator extracts NCG from the geothermal fluid. Isobutane is preheated and evaporated before entering the ORC turbine with a temperature of 133 °C and a pressure of 28 bar, where expands to the condenser pressure of 4 bar. Electricity is generated by a 17.5 MW axial ORC turbine and additionally by a 1.5 MW NCG turbine. The analysis revealed that the configuration without NCG turbine achieves a net efficiency of 12.73% and a net electric power of 13.68 MW while the configuration with NCG turbine achieves a net efficiency of 14.04% and a net electric power of 15.16 MW but with much higher CO2 emissions into the atmosphere.

  • Development and analysis of normative teqchnique for designing the small sea port facilities

    pg(s) 46-48

    At present, with rapid growth in maritime transport, the issue of improving the quality and reducing the time of design of marine terminals, ports and related facilities comes to the forefront. To this end, it is necessary to perform design works which are of integrated nature and are distinguished by high level of automation. The problem can be solved by creating a highly efficient automated system of design based on modern methods of engineering analysis and modeling

  • Thermodynamic analysis of a 500 MW ultra-supercritical pulverized coal power plant

    pg(s) 28-31

    This paper analyses the performance of a future planned 500 MW ultra-supercritical pulverized coal power plant. The steam cycle configuration comprises a single-stage reheat, four high pressure feedwater heaters, three low pressure feedwater heaters and the deaerator. The electricity generation unit consists of a high pressure turbine, an intermediate pressure turbine, two double-flow low pressure turbines and the electric generator. The analysis is carried out for live steam temperature of 600 °C and pressure of 300 bar while th e reheat steam temperature is 610 °C and the pressure is 50 bar. The condenser pressure is 0.039 bar. The analysis revealed that the ultra-supercritical power plant achieves a gross thermal efficiency of 47.39% and a net thermal efficiency of 45.14%. The specific CO2 emissions per unit of generated electricity are 733.4 kg/MWh. Relatively to existing subcritical units, the analyzed ultra-supercritical power plant achieves a net efficiency gain of 9%-pts. and a CO2 emission reduction of around 20%.

  • Alternative possibilities for application of foamed silicate materials

    pg(s) 25-27

    In summary form, some trends in the production and application of foamed silicate materials obtained from recycled waste materials are presented. The existing possibilities for the use of different fractions of foam glass granules for the preparation of various products (lightweight concrete, colored decorative panels, etc.) are considered. Experimental samples are prepared in which the average value of the thermal conductivity coefficient =0.24±0.13 W/m. K was established. The main technological factors determining the operational characteristics of the material and the existing potential prospects for their optimization are analyzed.

  • Modeling and experimental evaluation of the possibility of using a radial-shear rolling mill for recycling bar scrap of ferrous metals

    pg(s) 22-24

    This work is devoted to the study of the use of radial-shear rolling mills for recycling bar scrap and some metal products from ferrous and non-ferrous metals that have served their service life to obtain a ready-made commercial product. In particular, the paper presents the results of computer modeling and experimental research of the process of scrap metal rolling in the form of rebar on a radialshear rolling mill into a round cross-section bar, which prove that some metal products that have served their service life after recycling using the proposed technology into finished commercial products in the form of bars can find further use without remelting.

  • Survey of the geometric characteristics of a test specimen before punch sharpenings

    pg(s) 356-359

    This article analyses the widths and thicknesses of the test specimen after operating the punch before sharpening the guillotine blades. The principle of operation of a 3D computer tomograph with an accuracy of 3μm is considered. The analysis will be performed in two ways: by using a micrometer and a caliper and by using a 3D computed tomography for determining the width and thickness