Experimental Installation Research Articles

Automatic water level regulator with flexible working bodies in form of partition structure for trapezoidal channels

To improve the designs of hydraulic automatic water level regulators with flexible working bodies for channels, the object of research was developing and studying an innovative design of an autoregulator of the water level with flexible working bodies in the form of a partition structure for trapezoidal channels. The study℉s main purpose was to create a design for trapezoidal channels that do not allow channel narrowing and provides automatic level control, draining excess water, washing deposits in front of the partition, and determining its throughput. The developed design consists of a gate with flexible working bodies and a water level regulator combined with it. The article presents a theoretical formula for determining the flow rate of lateral water flows through the gate of the water level autoregulator. Experimental studies were carried out on an experimental installation by the method of physical modeling using the criterion of geometric similarity of the model and nature. As a result of these studies, simpler formulas were obtained for determining the flow rate of lateral water flows through the gate and a formula for determining the total flow rate of water passing through the gate of the water level autoregulator with flexible working bodies for trapezoidal channels for use during operation.

Autoregulatory of water level for channels of parabolic section and its capacity

The proposed design of the water level autoregulator with flexible working bodies for the channels of the parabolic section of the irrigation system is made in the form of a gate, which is a container formed by a rigid bottom, a pressure part made of flexible rubberized meliorative fabric, a rigid frame part of the spillway with a non-vacuum type profile covered with flexible meliorative fabric, and soft side elements also made of flexible rubberized meliorative fabric, which are a continuation of the pressure and spillway parts. Regulation of the water level in front of the autoregulator is carried out using a water level regulator. To determine the flow capacity of the gate of the proposed design of the water level autoregulator, a theoretical formula was derived, and experimental studies were carried out to determine the values of the flow coefficient included in this formula. The study was carried out on an experimental installation by the physical modeling method of the model and nature. As a result of the mathematical processing of the results of studies of the shutter model, an empirical formula was obtained for determining the shutter flow rate depending on the ratio of the iridescent water layer's thickness to the shutter's height. At the same time, the difference between the obtained values of the flow coefficients according to this formula and the results of experimental studies was +4...5 percent. This automatic water level regulator performs the function of a partition structure, does not require high costs, and can be portable and stationary; it is not metal-intensive, lightweight, transportable, combines the functions of stabilizing the required water level in the channel, dumping excess water, fin and debris, provides the necessary water enters the outlet openings of the channel.

THE METHOD OF THERMAL ENERGY RECOVERY OF EXHAUST GASES OF INTERNAL COMBUSTION ENGINE

In modern internal combustion engines, the part of the fuel energy that is consumed for useful energy is on average 35 percent. Up to 30 percent is spent during the combustion of fuel, which is removed with the exhaust gases of the engine. There are many ways to increase the efficiency of an internal combustion engine, one of which is a way to increase the efficiency by recuperating heat losses, implying the use of a device for converting thermal energy into electrical energy, operating on the Seebeck effect. (Research purpose) The research purpose is developing an experimental installation for the recovery of thermal energy from exhaust gases of an internal combustion engine into electrical energy and deducing the regularities of the thermoelectric generator in the power supply system in automotive equipment. (Materials and methods) Applied methods of numerical analysis and computer modeling using computer programs ANSYS Thermal Steady State and Solidworks FlowSimulation. A laboratory stand operating from the D-65 engine was used as a power plant (Results and discussion) The dependencies of the generated voltage and current of the thermoelectric generator on the temperature of the exhaust gases and coolant of the internal combustion engine were obtained. The maximum generated power of the developed thermoelectric generator was 54.5 watts. The maximum current of the thermoelectric generator during operation of the experimental installation was 3.7 amperes with an output voltage of 22 volts. (Conclusions) The use of the developed thermoelectric generator for the recovery of the energy of the exhaust gases of the internal combustion engine makes it possible to increase the use of the heat released during the combustion of fuel and provides an additional source of electrical energy.

Autoregulatory of water level with flexible working bodies for partition structures on channels

To improve the existing designs of hydraulic automatic gates with flexible working bodies for partition structures on channels, the object of the study was the development and study of an innovative design of an autoregulator of the water level with flexible working bodies. The study's main objective was to create a structure that provides automatic level control, discharge of excess water, washing of deposits in front of the partition, and determining its throughput. The developed design consists of a gate with flexible working bodies and a water level regulator combined with it. The article provides a theoretical formula for determining the flow rate of lateral water flows through the gate of the water level autoregulator. Experimental studies were carried out on an experimental installation by the method of physical modeling using the criterion of geometric similarity of the model and nature. As a result of these studies, simpler formulas were obtained for determining the flow rate of lateral water flows through the gate and a formula for determining the total flow rate of water passing through the gate of the water level autoregulator with flexible working bodies for use during operation.

Экспериментальное исследование работоспособности газодинамического подшипника

The question of the high-speed turbo machines operability is directly related to the processes occurring in the support structures – gas sliding bearings. The most common structure of such supports is the multi-petal bearing. One of the main research directions in this area is the development of a design ensuring the reliable operation of the bearing. The durability of gas bearings depends directly on the number of start-stop cycles, which is its key difference from liquid bearings. The start-up period of the turbo machine represents the most challenging mode of operation for the petal gas dynamic bearings. A critical feature of this mode is the insufficient formation of a gas layer at low rotational speeds. The load on the working surfaces of the support is assessed as nominal, equal to the rotor's weight. If the start-up mode of the turbo machine is successfully passed, then in future, during the acceleration, it will be operational. The research of the transitional mode during the start-up requires a complex approach, including both theoretical and experimental studies. This paper is a continuation of theoretical studies for multi-petal gas dynamic bearings with overlapping petals. The key parameters ensuring the operability of such supports include the shaft ascent speed at the start-up and the value of the force acting on the support. As part of the research, an experimental installation was developed to obtain values of shaft ascent speed depending on static load force. Series of experiments included different variations of initial loads, up to the critical value. The results of the experiments provide the values of permissible static loads and a range of shaft ascent speed values. This study facilitates further parametric investigations in the mathematical modeling of processes occurring in gas dynamic bearings.

Impact assessment of treated wastewater reuse for irrigation: growth potential and development of lettuce in Al Hoceima province, Morocco

The reuse of treated wastewater for agricultural practices is becoming increasingly important due to the growing demand for the transition to a circular economy. It has the major advantage of providing an alternative resource to the conventional water used for agricultural irrigation. The main objective of this work is to study, through tests on experimental installations, the effect of the type of irrigation water on the growth and development of lettuce. The types of irrigation water were prepared from purified wastewater, treated wastewater plus fertilizer, conventional water, and conventional water plus fertilizer. The physicochemical analyzes of wastewater from the Imzouren-Bni Bouayach WWTP resulted in different values of the parameters measured (pH, temperature, electrical conductivity, oxygen below, suspended matter, BOD5, COD, nitrate, nitrite and phosphorus) which fall within the limited range of direct discharges and comply with Moroccan standards for the quality of water intended for irrigation. The results of the characterization of the soil showed that it is a basic soil (pH= 8.5), unsalted (electrical conductivity = 2.43 ms/cm) and poor in organic and nutrient elements (Carbon 0.8%, organic matter 1.46%, nitrogen 0.06 mg/l, phosphorus 10.5 mg/l, potassium 56.4 mg/l.) The main results of the plant analysis show that the production level of this study crop irrigated with conventional water is similar to that of this study crop irrigated with treated wastewater. In other words, irrigation with treated wastewater allows lettuce to guarantee irrigated production at least at the level of conventional water. Another motivated addition of nitrogen, phosphate and potash mineral supplement in the treated wastewater improves the production potential of lettuce.

Selection and justification of the optimal multifunctional design of the unit for the preparation and distribution of liquid feed mixtures in animal husbandry

The article deals with the problem of using various installations for mixing and preparing liquid feed mixtures in animal husbandry. The analysis of domestic and foreign installations capable of performing this function is carried out. But during the review process, many shortcomings and problems were identified that needed to be solved by developing a new design that would eliminate all the identified problems. Therefore, the design of two installations in horizontal and vertical versions is proposed, while the values of their pressure-energy (hydraulically) characteristics are given. This allowed us to determine their further expansion of functionality. This is how the process of drinking and feeding was considered, using experimental installations. The parameters for each livestock room are analytically calculated, which shows the effectiveness of the use of experimental installations.

Intensification of heat transfer during condensation of water vapor on a vertical tube

A review of the scientific literature on the intensification of the heat exchange process during condensation of water vapor on the surface of a vertical tube is carried out and the main results of the study are presented. The work on the study of heat transfer during laminar condensation of water vapor in the form of a laminar-flowing liquid in the form of a film both inside and on the outer surfaces of vertical tubes with an ascending steam flow is analyzed. The numerical values of Nusselt and Reynolds, which are also known and proposed for the case under consideration, have been studied. Methods of intensification of the heat exchange process are presented by improving the geometric configuration of the heat exchange surface from the side of the heating steam, on which its condensation occurs during heat transfer, which consists in reducing the thermal resistance of the wall molecular layers of the liquid. This method helps to increase the coefficient of heat transfer from steam to the wall surface by increasing the surface area of heat exchange. Based on the study of the results of well-known works, the authors have developed an experimental laboratory installation to study the increase in the efficiency of water vapor condensation processes on the outer surface of a vertical tube. An important scientific problem to be solved is the breakdown of the laminar-flowing liquid of condensed steam from the heat exchange surface, which leads to the admission and contact of steam directly from the cold surface of the tube.

ЕКСПЕРИМЕНТАЛЬНІ ДОСЛІДЖЕННЯ ГІДРОДЕЗІНТЕГРАЦІЇ МАРТИТОВИХ ЗАЛІЗНИХ РУД ОБЕРТОВИМИ СТРУМЕНЯМИ ВОДИ

Purpose. Obtaining the main initial experimental data to establish a set of calculated dependencies for determining the parameters of the process of hydrodisintegration by boreholes of rich martite ore deposits, for further designing an industrial mine site for hydraulic mining by boreholes and a production technological complex for actual mining. Methods. Testing of an experimental hydraulic monitor installation and equipment for the implementation of the technological process of hydrodisintegration of rich martite ores through production wells with a diameter of 105 mm. Refinement of the criterion for the hydrodisintegration of rich martite ores by pressure jets of medium diameter, in the conditions of natural occurrence of the ore deposit. Determination of the influence of the pressure of the working diameter of the jet and the speed of its movement along the exposure of the face on the range and productivity of hydrodisintegration. Determination of the influence of the geological and structural characteristics of the ore deposit on the parameters of the hydrodisintegration process. Establishment of rational regimes for the impact on the ore massif of a rotating jet to obtain a given granulometric composition of the ore mass. Results. Through wells with rotating jets of water, the fundamental possibility of hydrodisintegration of arrays of rich martite ores with an iron content of more than 65%, a porosity of more than 20% and a uniaxial compressive strength of less than 20 MPa has been proved. It has been established that the hydrodisintegration of of rich martite ore massifs begins with the penetration of pressure water into cracks to a depth of 0.10–0.15 m. At the same time, an increase in pressure in the jet nozzle increases the productivity of the hydraulic monitor, and the use of two rotating jet nozzle increases the productivity of the hydraulic monitor by 2.7 times. The process of hydrodisintegration is accompanied by an increase in the mass fraction of iron in the ore from 67.2 to 68.2%, due to the removal of barren particles and sludge from the slurry. Hydrodisintegration provides a high degree of disclosure of ore minerals, 40–60% higher than in the process of mechanical grinding in a grinding mill. Scientific novelty. The dependence of the change in the performance of the hydraulic monitor and the specific water consumption on the water pressure in the jet nozzle has been established. The dependence of the change in the percentage of iron in the disintegration products of martite ore on the class of their size has been obtained. Practical implication. The use of hydrodisintegration by boreholes of deposits of rich martite ore in the course of their underground mining provides an increase (above natural) in the quality of the extracted ore raw materials and and its beneficiation directly at the place of extraction.

Токсичность продуктов термолиза и дымообразующая способность огнезащитных вспучивающихся покрытий для стальных конструкций

PURPOSE. The work considers intumescent fire-proof coatings for steel building structures of various component compositions, as well as the fire-proof action mechanism of intumescent systems. Taking into account the results of previous researches and our own experience in the development of fire-proof materials for steel structures, chemically balanced formulations of intumescent coatings have been formed. Based on the study of smoke-generating ability and thermolysis products toxicity of intumescent fire-proof coatings, the possibility of their participation in changing the general toxicological situation when exposed to high temperatures (fire), as well as in the formation of smoke is noted. The main objective of the work is to study the dynamics of thermolysis toxic products release during thermal decomposition of intumescent coatings, their smoke-generating ability, as well as to establish the possibility of reducing density of the released thermolysis products and the smoke generation coefficient when using combinations of intumescent coatings. METHODS. As part of the work an express assessment of the fire-proof effectiveness of various intumescent coatings has been carried out using an experimental radiant heating installation, as well as dynamics of thermolysis products release under thermal influence on steel samples with fire protection. In addition, to study the smoke-generating ability of intumescent fire-proof systems, a method of experimental determining the smoke generation coefficient of solids and materials has been used. FINDINGS. According to the express assessment results of fire-proof efficiency the time to reach the critical temperature of steel samples with the studied intumescent coatings is at least 30 minutes. It has been found that when using an original type of fire protection(a combination of intumescent coatings), it is possible to reduce the density of the released gaseous thermolysis products, as well as the value of smoke generation coefficient. RESEARCH APPLICATION FIELD. The results of the study can be used to predict the dynamics of hazardous factors development during a fire in a building or a structure, taking into account the contribution of the developed intumescent fire-proof coatings to the general toxicological situation. CONCLUSIONS. As part of the work an original type of fire protection for steel structures, including combinations of intumescent fire-proof coatings, has been proposed. A synergistic effect has been discovered as a result of intumescent systems combination use in comparison with the results obtained for the corresponding individual compositions that are part of these combined coatings layer by layer. The effect of filtration in reducing thermolysis toxic products yield and smoke generation of fire protection, which is based on the filtering effect of the outer intumescent layer of the combined system, has been established.

DESIGN PARAMETERS OF THE HELIO INSTALLATION FOR HERBS DRYING

In order to dehydrated feed production's energy consumption reducing, work is underway aimed, on the one hand the drying modes that the safety of nutrients and vitamins ensure clarifying, and on the other hand the dehydration methods improving, new progressive technologies without the quality of processed feed compromising would dramatically energy costs'reduce creating. From this point of view, a new progressive method of drying feed solar energy use attention deserving. The possibility of using solar energy for herbs' artificial drying is facilitated by the fact that the drying season coincides with the greatest solar radiation period. Based on Turkmenistan climatic conditions analysis, a helio installation that combines the advantages of conveyor and pneumatic drum dryers and works with a coolant having a low temperature (about 70-100 °C), but supplied under pressure has been developed. A method for the solar dryer's thermal and structural parameters calculating is proposed. Based on the calculated data, an experimental helio installation was built, due to experimental studies on drying alfalfa using solar energy were carried out, as a result of which hay with a carotene content of 208 mg/kg at a humidity of 21,4% and grass cutting with a humidity of 12-14% with a carotene content of 224-249 mg/kg was obtained. This helio installation's introduction for herbs drying will reduce feed preparation's fuel consumption, feed production quality and labor production improving.

Условия проведения и баллистическая схема космического эксперимента по беспроводной передаче электрической энергии

The paper discusses conditions for conducting sessions of the Pelican space experiment on wireless transmission of electrical energy in the laser channel between the Russian Segment of the International Space Station and the Progress transport cargo spacecraft. Experiment objectives, composition and installation of the Pelican scientific equipment for its implementation are briefly considered. Ballistic schemes that meet requirements for conducting the space experiment, as well as the safety requirements, are proposed. Feasibility of the experiment sessions is shown from the point of view of compliance between parameters of the Progress spacecraft and the Station relative motion and capabilities of the emitter guidance system elements. Characteristic speed expenditures were evaluated with the Progress spacecraft maneuvering to perform repeated passages of the station. The estimates obtained confirm possibility of at least five sessions of the space experiment with one Progress spacecraft.

INVESTIGATION OF THE OPERATION OF ELECTRICAL EQUIPMENT FOR FEEDING PLANTS WITH CARBON DIOXIDE IN PROTECTED SOIL

Carbon dioxide, along with nutrients, light and water, serves as one of the most important factors for growing plants. But the carbon dioxide contained in the atmosphere may not be enough. In modern crop production, they are increasingly inclined to use additional equipment, with the help of which the CO2 fertilization of plants is carried out. At the same time, control over the processes of vegetation and flowering (fruiting) improves. (Research purpose) The research purpose is creating an experimental setup and conduct experiments. Determine the external parameters that affect the maintenance of the required CO2 level. Find ways to control the concentration of carbon dioxide, independent of external conditions. (Materials and methods) Analyzed domestic and foreign literature, based on their own works on this topic, conducted experiments. An experimental installation for spraying carbon dioxide in a volume simulating the construction of protected soil was installed. (Results and discussion) We performed 4 measurements with a time difference of 2 hours. It was shown that the experimental setup based on the compiled algorithm levels the influence of external factors and keeps the set value of CO2 (600 ppm). Readings were taken from sensors located in the area of carbon dioxide cloud spraying, adjustments were made by affecting the operation of electric nozzles. (Conclusions) It was found that it is possible to solve the problem of lack of carbon dioxide when growing plants in the construction of protected soil. For this purpose, it was proposed to use carbon dioxide supply units directly to plants, capable of taking into account and correcting the movement of gas in the construction of protected soil. The results of the experiments carried out on the operation of electrical equipment for feeding plants of protected soil with CO2 were presented.

Оценка влияния протокола Openflow на производительность сетевых устройств

A very promising area of computer network technologies is the use of Software Defined Network (SDN). The principles of SDN first emerged in the Stanford and Berkeley research laboratories and are currently being developed as part of the Open Network Foundation consortium and the European project OFELIA. The openness of the OpenFlow standard and the introduction of control logic into a separate controller simplifies the software and hardware of active network equipment, which will allow manufacturers to reduce its cost in the future, and therefore reduce the cost of creating computer networks. Therefore, research in this area is very promising. This work is devoted to the study of the performance of SDN, namely, how the implementation of the OpenFlow protocol affects the quality of data transfer between network devices. Using a single stream, the maximum throughput is estimated. To do this, three experimental installations of a network with different network devices, a switch, a router and an OpenFlow device, as well as a dedicated Linux server with support for the OpenFlow protocol, are assembled. The essence of the experiments is to change the size of packets and the size of the forwarding table to assess the performance of SDN with different network devices. The results of the analysis showed that the implementation of OpenFlow on Linux systems is able to offer very good performance. OpenFlow shows good performance with a large number of threads.

Двухэтапная обработка лопаток компрессора ГТД методом сухого электрополирования

The paper considers a two-stage technology of dry electropolishingof GTE blades and an experimental installation for this process. The results of comparative tests of the traditional and developed technologies for polishing parts of complex configura-tion, as well as information about the design of the installation for two-stage polishing of the GTE blades are presented. It is shown that the two-stage processing technology of the blade airfoil can significantly improve the quality and uniformity of the surface of the part

EXPERIMENTAL STUDY OF HEAT EXCHANGE PROCESSES IN HEAT EXCHANGERS OF A NEW DESIGN FOR COOLING SUPPLY AIR IN POULTRY HOUSES WITH WATER FROM UNDERGROUND WELLS

In this work, an experimental installation for cooling air in a poultry house was developed and manufactured using a new design of a heat exchanger-recuperator, in which water from underground wells is used as a cooling medium. The schematic diagram of the heat exchanger installation and device is described, and the characteristics of the measuring instruments are given. Experimental studies of heat exchange processes in the heat exchanger were carried out and the temperature distributions in the cold and hot coolants were determined, the Nusselt number and the heat transfer coefficient on the surface of the tube bundle were found. It is shown that the use of a new design of compact tube bundles makes it possible to increase the heat transfer coefficient by 33 %. Based on the statistical analysis, the results of numerical model calculations are compared with experimental data on the heat transfer of pipe bundles. The error obtained in the results of numerical modeling is slightly more than 5 %.

INTERACTION OF MICROBIOLOGICAL AND MEMBRANE TECHNOLOGIES OF WASTEWATER TREATMENT

The combination of microbiological and membrane technologies for wastewater treatment from organic substances of various origins is considered. An experimental installation of a membrane-distillation bioreactor is proposed. When carrying out the proposed wastewater treatment in one device, the process proceeds in two stages. The first stage is biological treatment under anaerobic conditions of biogas production, and the second stage is post-treatment using membrane distillation on ultrafiltration membranes. We analyze anaerobic wastewater treatment through horizontal channels by passing through media - thin-sheet filter loads (drains), which contain immobilized microorganisms that form a biofilm layer. Anaerobic digestion is accompanied by the production of biogas, which is collected and discharged into a special tank. Under the action of bacteria during the acetogenic phase, acetic acid is additionally produced from the substances formed in the previous phase, which is decomposed into methane, carbon dioxide and water during methanogenesis. It has been shown that ultrafiltration membranes are used as a wastewater treatment. It is proved that wastewater diffuses through the drainage under the influence of a pressure drop of 200 mmHg and at a temperature of 35-38 °C. It is determined that the treated water can have a high content of organic matter from 100 to 104 mg of impurities/liter of water. As a result of the anaerobic process, the biogas yield was found to be from 0.1 to 6 m3 of biogas/(m2∙day), depending on the content of organic matter in the wastewater. A continuous process of wastewater treatment in a closed technological cycle is proposed.

Лабораторное исследование дозирующего устройства для кормовых добавок

The experimental study presented in the article forms the basis for designing a dispenser servicing a robotic feed table on livestock farms. In the introduction, the author analyzes trends in the development of machines for on-farm production of compound feeds using dosing and weighing equipment, and describes the role and key performance indicators of the use of compound feeds of on-farm production for livestock breeding complexes. The articles presents a method for optimizing the design parameters of screw-type feed additive dispensers, a schematic diagram and a photo of an experimental installation. To control the electric motor of the experimental installation, a mathematical model was developed that takes into account the electric motor speed. A second-order mathematical model was used as a mathematical framework for processing experimental data, constructing response surfaces and regression equations. The experiment assumed a fi ve-fold weight measurement of the dosing error of feed additives for each type of the screw design.

Particularities of flue gases from energy installations on the process of continuous flow capture for CO2 by direct methanation

The efficiency of the direct methanation of the flue gases from the energy installations is influenced both by the relatively low participation of the CO2 component and by the presence of water vapor and oxygen from the excess air. The water vapor content reduces the efficiency of the methanation process by a small percentage. The excess air has been analysed in the paper in more detail to determine whether it can lead to the process of self-ignition (explosion) of hydrogen in the phase of its admission to the methanizer. Thus, an analytical calculation was performed for the composition of the flue gases from an energy installation that uses liquid fuel, the excess air being 1.3. At the end of the paper, the objectives of the experimental tests to be performed were presented, and details regarding the complex experimental installation and the already achieved methanizer were provided.

Temperature gradient of the natural water surface thermal radiation

The dependence of the thermal radiation of natural water on its kinetic temperature in the temperature range of 7-70 degrees Celsius was experimentally investigated. The measurements were carried out on an experimental installation FPK-11 with a thermocouple as a receiver of integral thermal radiation. The measurements were carried out outdoors at an ambient temperature of about zero degrees Celsius. The water temperature was measured by a contact thermometer immersed in the water column. In the temperature range of 28-40 degrees Celsius, a decrease in the thermal radiation of water was revealed with an increase in its kinetic temperature. A “hump” of thermal radiation in the range of 7-40 degrees with a drop in thermal radiation of about 10% of the maximum was revealed. The value of the contrast in the studied temperature range makes it possible to detect thermal contrasts of the hydro objects surfaces. It was proposed to use the thermal radiation of pure water as a reference for measurements. The conditions of practical use of temperature dependences of the thermal radiation of water for environmental monitoring of water surfaces are proposed.