Технические науки. Рубрика в журнале - Бюллетень науки и практики
Experimental study on a pulsation-enhanced heat transfer device
Статья научная
The pulsation-enhanced heat transfer technology is introduced, and a volume coil heat exchanger is designed. A pulsation valve is installed at the heat exchanger outlet of the heat exchanger to pulsate the heat medium, and the same heat exchanger is subjected to pulsation and non-pulsation heat transfer tests. Based on the experiments, combined with the theory of pulsation-enhanced heat transfer technology, heat transfer capacity, heat flow, and convective heat transfer coefficient coefficients, the effective temperature difference, heat flow, and convective heat transfer coefficient of the heat exchanger at different pulse frequencies are analyzed. The relationship between the pulsation frequency of the heat transfer effect of the heat exchanger is obtained. The test results show that the heat exchanger has higher heat exchange efficiency when there is pulsation under the test conditions.
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Experimental study on heat transfer and pressure drop in plate heat exchanger using water-water
Статья научная
It would be misguiding to consider only cost in design of a heat exchanger because high maintenance costs increase total cost during heat exchanger’s services life. Therefore, exergy analysis and energy saving are very important parameters in heat exchanger design. In this study, the effects of pate heat exchanger (PHE, Ridan HHN no. 04) on heat transfer, friction factor and exergy loss were investigated experimentally. Experiments were conducted from laminar flow condition to turbulence flow condition under counter flow condition. Reynolds number and Prandtl number were in the range of 220
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Experimental study on heat transfer of pulsating flow enhanced the plate heat exchanger
Статья научная
We conducted two sets of experiments, one is under steady-state conditions and the other under pulsating conditions. We focused on measuring the heat transfer characteristics of plate heat exchangers under different pulsation conditions. In the experiment, we control the mass flow of the hot fluid to circulate at a rate of 0.722 kg/s. The mass flow rate of the cold fluid is 0.05-0.18 kg/s, and the pulsation frequency is 0.45-2.23 Hz. We measured different mass flows at different pulsation frequency. The data analysis shows that when the pulsation frequency is 1.78 Hz, the heat transfer coefficient reaches a maximum of 4415.73 w/(m2·k), and the corresponding cold fluid mass flow rate is 0.155 kg/s, and compared with the heat transfer characteristics of the plate heat exchanger under steady flow, it is found that the average increase in the heat transfer coefficient during the transition to the pulsating mode was 20%.
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Experimental study on unidirectional flow characteristics of flow diode
Статья научная
Flow diode is a kind of control fluid one-way flow of components, it has many advantages, such as simple structure, no rotating parts, no need for external control, power, high reliability, in the medical industry, nuclear industry, petrochemical industry, flow diode has a wide range of applications. By studying relevant literature, combined with the actual situation, based on the experimental study method, using air pump, pressure regulator, 3 d printers and other laboratory equipment, by changing the pump seal the air inlet, simulation of different flow diode under different conditions make the fluid flow through, will pump displacement into displacement, record each air inlet in unit time displacement, and then compared these data, the flow is obtained by carefully analyzing the flow characteristics of diode and the relationship between the fluid flow characteristics diode, it is concluded that: the displacement increases with increase of voltage; when the aperture changes, the flow diode will produce important changes; unstable flow characteristics of variable diameter flow diode.
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Статья научная
The article is devoted to the determination of the optimal parameters of a dielectric fluid as an impregnant in power capacitors. The optimal parameters for the synthesis of the ester are found on the basis of a not clear Mamdani model. The model providing optimization of the chemical process is offered and on the basis of statistical data, the algorithm of training of the fuzzy model is developed. The goal was solved with fuzzy data and a regression model of the three-stage process was obtained. Optimization was carried out and optimum parameters were found. Based on the statistical data, a fuzzy Mamdani model was compiled.
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Hadrian X - автономная роботизированная система для кладки кирпича
Статья обзорная
Рассматривается разработка инновационной системы для автономной кладки кирпича Hadrian X от компании Fastbrick Robotics, которая позволяет выстраивать дома из кирпича в автоматическом режиме без участия человека. Рассмотрены преимущества и недостатки данной разработки, а также области применения и перспективы развития в строительной области. Выявлены направления развития и совершенствования данной системы. Является лучшим способом строить типовое недорогое жилье за очень короткие сроки.
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High power led fish collector heat sink
Статья научная
High-power LED fish collector lamps are small in size and work with high heat flow density, LED chips emit more and more heat, and heat dissipation problems have gradually become a bottleneck limiting the development of LED. In this paper, for a typical power LED, it mainly discusses the LED packaging technology, the heat sink structure and characteristics of the impact on the heat dissipation conditions.
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Hot water heating circuit with impulse cavitator
Статья научная
An effective method of multifactorial influence on a liquid is cavitation, which leads to a change in the physicochemical characteristics of the liquid, its activation and heating. One of the devices, the principle of which is based on cavitation, is a cavitation heat generator. At present, the production of these units has been mastered by many manufacturers, and they appear in large numbers on the world market. Among the numerous designs of cavitation heat generators, a worthy place belongs to jet ones, which have the lowest pressure drop, but their efficiency is relatively low (from 20% to 40%) and does not meet modern requirements. The purpose of this work is to increase the efficiency of water heating in a cavitation heat generator based on the use of a pulsed mode of its operation. To achieve this goal, the following tasks were identified in the work: to develop a laboratory sample of a flow-pulse cavitator; to develop a diagram of a laboratory setup and a cavitator design; conduct hydraulic and thermal tests of the cavitator prototype, obtain the results and evaluate their effectiveness. Thus, the successful implementation of the goal of this work may encourage many industrial enterprises and households to abandon traditional heat supply systems and switch to modern sources of thermal energy, namely jet cavitation heat generators with a pulsed cavitator.
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How to learn and control effective hybrid cars
Краткое сообщение
The article deals with the history of hybrid cars, their types, running principle, parts, characters, advantages and negative features. Hybrid cars combine the efficient features of an electric motor and an internal combustion engine, and the use of hybrid cars in Azerbaijan, as in other countries, is satisfactory.
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Hydrodynamics of Absorption Bubbling Apparatus
Статья научная
The article proposes an improved design of the energy-saving, compact absorption bubbling apparatus, which cleans the particles and gas mixtures in the exhaust gases of industrial enterprises, has a high absorption efficiency. As a result of theoretical research, an equation has been proposed that calculates the value of the height of the gas cushion “h”, which provides equal distribution of purified gas to the mixing sections of the apparatus and operation in a stable hydrodynamic mode. As a result, depending on this value, it is possible to calculate the gas velocities and the gas consumption supplied to the apparatus.
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IPtables для обеспечения безопасности информационных сетей на базе Linux
Статья научная
В статье рассмотрены основные компоненты информационной безопасности: конфиденциальность, целостность и доступность. Пароли, шифрование, аутентификация и защита от проникновения - это методы, предназначенные для обеспечения конфиденциальности. Целостность означает поддержание данных в исходном состоянии и предотвращение их изменения: случайного или злонамеренного. Под обеспечением доступности информации понимают соответствие сетевых и вычислительных ресурсов ожидаемому объему доступа к данным и реализацию политики резервного копирования для целей аварийного восстановления. Для обеспечения безопасности информационных сетей на базе RedOS наилучшим образом показала себя утилита iptables, используемая для настройки брандмауэра ядра Linux. Несмотря на то, что на первый взгляд реализация IP-маршрутизации в Linux может выглядеть довольно сложной, на практике наиболее распространенные варианты использования (NAT и/или базовый брандмауэр Интернета) значительно проще реализуются. Iptables - это пользовательская утилита, позволяющая работать цепочками/правилами. В статье подробно рассмотрены принципы работы iptables, приведено подробное описание таблиц nat, mangle, filter, raw и цепочек. Таблица nat используется для трансляции сетевых адресов, mangle применяется для искажения пакетов, filter дает возможность выполнять фильтрацию пакетов, raw и ее цепочки используются перед любыми другими таблицами в netfilter. Цепочка input применяется для обработки входящих пакетов и подключений, forward - для проходящих пакетов, output - для исходящих пакетов. Показано, что для обеспечения безопасности функционирования компьютерных классов и всей сетевой инфраструктуры в целом, достаточно только двух таблиц: filter и nat. Другие таблицы предназначены для сложных конфигураций, включающих несколько маршрутизаторов и решений по маршрутизации. Приведены результаты использования iptables на основе опыта администрирования информационных сетей на базе RedOS в федеральном государственном бюджетном образовательном учреждении высшего образования «ПГУТИ».
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ISO 9000 quality standards implementation in the petroleum engineering plants of Baku
Статья научная
We carried out a comparative analysis of ISO 9000, API Ql, and the Russian GOST standards currently applied in domestic engineering plants to the manufacture of the oilfield equipment such as “xmas trees”, string heads, and well enclosing equipment.
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Increasing of magnetic devices lifting capacity and its efficience in shut down wells
Статья научная
The effectiveness of the point of application of force for lifting the objects from the bottom of oil and gas wells has been investigated. It the proven, that if the force to lift the deposited objects is applied not at the center of gravity of the object but at one end, then the force required is four times less than the force applied to the center of gravity of the object.
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Influence of at winglets wingtips on the inductive reactance of the wing
Статья научная
In this article by the method of equations of steady horizontal flight the impact of AT winglets wingtips on the inductive reactance of the wing is explored. The total aerodynamic force, created by all four parts of the wingtips is determined. The vector of the total aerodynamic force of the wingtips is represented in the form of components of a linked coordinate system. Equilibrium equations for the steady motion of an aircraft with AT winglets wingtips in a horizontal flight are recorded. From these equations it is obtained that, in the direction of motion, the longitudinal component of the vector of the total aerodynamic force of the tips reduces the inductive drag of the wing, the vertical component is added to the lifting force of the wing, and the lateral component, due to symmetry, is zero. It is shown that the lifting force created by the AT winglets wingtips is larger compared to the same ones created by the upper tips. An important consequence is that the distribution of the lifting force over the wing span with double tips is more even in comparison with the wing without a tip or with a wing with the upper wingtip. The expression for the effective aspect ratio of the wing with the tips is determined, which is greater than the inductive drag of the wing without the tip. An interesting result is obtained: for identical aircraft weights, the product of effective aspect ratio of the wings with double and only upper wingtips on their coefficients of inductive resistance is equal to the product of the wing aspect ratio without a tip on its coefficient of inductive resistance. This law can also be formulated as follows: at the constant weight of the aircraft, the effective aspect ratio of the wing with the tips by its coefficient of inductive resistance is a constant value, independent of the form of wingtips.
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Influence of wingtip type at winglets on the aerodynamic quality of wings
Статья научная
In this article by the method of equations of steady horizontal flight the impact AT winglets wingtips on the wing aerodynamic quality is explored. Determine the total aerodynamic force, created by all four parts of the endings. The vector of the total aerodynamic force of the endings is found in the form of components along the associated coordinate system. Equilibrium equations for the forces acting on the aircraft are recorded, with the linear motion of the aircraft with wing tips of the AT winglets type in a horizontal flight established. From these equations it is obtained that, in the direction of motion, the longitudinal component of the vector of the total aerodynamic force of the tips reduces the drag of the wing, and the vertical component increases the lifting force and this increases the aerodynamic quality of the wing. The components of the vector of the total aerodynamic force in the transverse direction from the left and right ends of the wing counterbalance each other By virtue of symmetry. Naturally, provided that the weight of the aircraft is constant and the speed of a straight horizontal flight, the angle of attack of the aircraft with the wing with endings like AT winglets should be reduced in order to observe the equality of the lift and the weight of the aircraft. A decrease in the angle of attack, in turn, leads to a decrease in the drag force. The effect of the aerodynamic wing tips on the maximum value of aerodynamic quality is studied. The expression for the aerodynamic lift coefficient at the most advantageous angle of attack is found. It is shown that the aerodynamic wing tips reduce the coefficient of lift of the wing without endings at the most advantageous angle of attack.
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Logistic management of environmental safety of passenger transport
Статья научная
Analysis of air samples taken from the dense traffic sections of urban transport of different compositions revealed that the value of NOX, CXHy and CO emitted into the environment by vehicles depend on the traffic flow density and composition. It has been revealed that in those areas of the urban traffic networks where the urban passenger transport prevails in the traffic flow composition, the indicator of traffic-related air pollution is much higher, so the management of the road transport processes by using the logistical arrangements of the traffic flows should be carried out taking into account the environmental safety criteria. The paper dwells on three different levels of management of environmental safety of vehicles as follows: the mega-level of the formation of regional transport; the micro-level of management of passenger routes, and the individual level (driver - vehicle) of traffic management.
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MgH2 insights used for hydrogen storage and catalysis: preparation, characterization and mechanism
Статья научная
Magnesium is a rich element on earth, with high reversible, cycle stability and antitoxicity, low cost, and high-volume hydrogen capacity, its theoretical hydrogen storage capacity up to 7.6 wt %. Magnesium-based hydrogen storage materials are considered as one of the most promising hydrogen storage media. However, due to its high thermodynamic stability and slow hydrogen adsorption kinetics, the high adsorption temperature and long adsorption time limit its practical application. In order to overcome the thermodynamic and kinetic obstacles of magnesium-based hydrogen storage materials in practical application and improve the hydrogen storage performance of MgH2, catalytic modification is a very effective method at present. This review summarizes the preparation methods, characterization methods and reaction basis of various catalysts modified by MgH2. Finally, we analyze the development trend of various catalysts in the future, as well as the application prospects.
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Model of a heat exchanger air heating booster
Статья научная
To solve the problem of energy crisis in today’s world, energy conservation is more and more get the attention of people, heat exchanger occupies an important place in the field of energy saving, however, because of the heat exchanger is a traditional energy-intensive heavy industry, one of the most widely used equipment in it as preheating, mainly in the process of waste heat recovery, refrigeration equipment, made outstanding contributions to energy saving. In this paper, spiral plate heat exchanger as the research object, select the established model, through the analysis of the existing heat transfer enhancement theory, combined with the classical optimization algorithm genetic algorithm spiral plate heat exchanger programming optimization, through iterative calculation to get the optimal spiral plate heat exchanger structure parameters. On this basis, based on the theory of dissipative, puts forward a new physical volume of fire, and established a new heat exchanger performance evaluation standard unit total cost model of heat transfer, and the objective function, analyzes the structural parameters in the spiral plate heat exchanger (cold and hot fluid flow, heat exchanger, plate spacing) and their relationship. Because the total cost per unit heat transfer not only considers the thermodynamic performance of the heat exchanger but also the economic feasibility of the heat exchanger. Finally, combined with the simulation calculation of the performance of the heat exchanger before and after optimization structure parameters, further analysis of its internal flow. The research in this paper provides a theoretical basis for the design, structure optimization and performance prediction of spiral plate heat exchanger.
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Model of a microchannel heat exchanger of a supercharger for heating water
Статья научная
The subject of the research is a model of a microchannel heat exchanger of a supercharger for heating water. The purpose of study is to simulate the heating effect of microchannel heat exchangers for heating water and to evaluate their effectiveness in practice. Research methods: comparison, synthesis, modeling, description, experimentation, graphical analysis. As a result of the study, the prerequisites for the energy conversion of the microchannel heat exchanger, the heating unit, the energy conversion unit, and the biofuel storage unit were considered and put together. The degree of implementation is complete. Efficiency of development - in order to enhance energy use and reduce losses in energy use, thereby protecting the environment and saving energy.
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New method of using mobile robots for moving cargo in warehouse
Статья научная
The new patented method for moving cargo in warehouse is proposed in this article. According to the new method, movement of cargo from the storage area to another warehouse area is carried out by throwing the cargo by the first mobile robot and catching the thrown cargo on fly by the second mobile robot. The parameters of the calculated trajectory of movement, in the free flight phase, of the center of mass of the cargo to be thrown are calculated by numerical methods for solving the Cauchy problem for a system of ordinary differential equations, and by the shooting method for boundary value problems of a system of ordinary differential equations. The first mobile robot throws the cargo at the specified angle to the horizon with the specified initial velocity, at the specified moment of time. In order to catch the thrown cargo on fly by the second mobile robot, the parallel algorithm A1-A2 for catching a thrown cargo on fly by the second mobile robot was created. The method allows the first mobile robot to throw cargoes for large distances, and the created algorithms allow the second mobile robot to catch reliably the thrown cargoes on fly. The proposed method for moving cargo is superior in economic efficiency and reliability to the other methods for moving cargo by implementing tossing of inventory items by robots.
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