Технические науки. Рубрика в журнале - Бюллетень науки и практики
New wireless technology for data transmission in chemical systems
Статья научная
New type of wireless computer network in chemical systems is presented in this article. This wireless network uses chemical system as physical media for data transmission, instead of environment. Thus, represented wireless network differs substantially from molecular communication networks and wireless networks covered by IEEE standards, such as radio frequency based wireless networks. This new wireless technology can be used not only in chemical industry for continuous controlling chemical processes in chemical reactions zones but also for medical purposes, and as a new type of wireless body area computer network.
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Статья научная
The spatial distribution of heavy oils and natural bitumen’s depending on their reserves is analyzed. It is shown that due to the deterioration of the structure of the reserve in the direction of increasing the share of hard-to-recover oils, the role of heavy oils and natural bitumen’s in the overall hydrocarbon balance increases. Analysis of reserves showed that most of their world reserves are concentrated in Canada, Venezuela, and Russia. The results of studies of the distribution patterns of heavy oils and natural bitumen’s can be used in improving methods of field search and in solving other problems of the oil industry.
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Статья научная
Baffle heat exchanger is widely used in various production activities because of its simple design and strong adaptability, so the structural optimization of baffle heat exchanger is of great significance to engineering practice. COMSOL software was used to simulate the shell-and-tube heat exchanger with baffles. By comparing and analyzing the simulation results, we find that the temperature field and pressure field of baffle plate are distributed evenly; The existence of baffles leads to the transverse flow of air, which increases the heat exchange area. Another advantage of using baffles is that vibration due to fluid flow can be reduced.
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Numerical simulation research on cavitation flow of different fuels in diesel engine injectors
Статья научная
With the increasingly stringent requirements of diesel engine fuel consumption and pollutant emission, higher requirements are put forward for the performance of diesel engine fuel injection systems. Cavitation flow in diesel fuel injectors is an extremely important factor affecting spray characteristics. In this study, the occurrence of cavitation in the fuel injector nozzle and its impact on mass flow rate and vapor fraction at the outlet of the fuel injection hole are studied numerically for various fuels such as diesel, gasoline, ethanol and methanol. The results show that the mass flow rate of diesel is the highest and that of gasoline is the lowest. Methanol and gasoline have the highest vapor content, followed by ethanol, and then diesel with the lowest vapor phase. For mass flow, the mass flow is inversely proportional to the viscosity of the fuel, and for cavitation, the amount cavitation is inversely related to the viscosity of the fuel. This agrees with many researchers’ findings.
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Статья научная
The accommodation of renewable energy is driving the development of energy storage technology, and shared energy storage has gained widespread attention because of its decentralized nature. In the optimal scheduling of shared energy storage, the problem of benefit distribution among multiple subjects is faced, so a shared energy storage plant operation optimization method based on Nash bargaining theory is proposed. The article constructs a joint model of shared energy storage plants and industrial users, establishes the cooperative operation model of each operator based on Nash bargaining theory, equates this nonconvex nonlinear problem into two subproblems of system revenue maximization and power transaction payment bargaining according to the mean value inequality, and uses the alternating direction multiplier method to solve them in a distributed manner. The algorithm selects three typical industrial users to participate in the joint system of shared energy storage, and through comparative analysis before and after cooperative bargaining, it is concluded that the proposed optimization method can effectively improve the benefits of each subject, while promoting the accommodation of new energy.
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Optimal design of heating boilers
Статья научная
Instead of a regular flywheel, it is possible to install a lightweight, with a variable moment of inertia on the electric unit, which will accelerate faster, which means it is faster to enter the mode of the rated frequency of the generator output voltage. In a mode close to the nominal speed of rotation, the moment of inertia will increase sharply, which will allow more mechanical energy storage, which will not allow to slow down the speed of the internal combustion engine, so it is better to damp (smooth out) the low-frequency external disturbances from the side of the electrical network.
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Статья научная
The integrated energy system (IES) is an effective way to achieve the “carbon neutrality and emission peak” goal. In order to further explore the role of the adjustable potential of demand side on carbon emission reduction, an optimized operation model of IES considering the demand response under the carbon trading mechanism is proposed. Firstly, according to the characteristics of load response, the demand response is divided into two types: price-type and substitution-type. The price-type demand response model is established on the basis of price elasticity matrix, and the substitution-type demand response model is constructed by considering the conversion of electricity and heat. Secondly, base-line method is used to allocate free carbon emission quota for the system and considering the actual carbon emissions of gas turbine and gas boiler, a carbon trading mechanism for the IES is constructed. Finally, a low-carbon optimal operation model of IES is established, whose objective is to minimize the sum cost of energy purchase, cost of carbon transaction and cost of IES operation and maintenance. The effectiveness of the proposed model is verified through four typical scenarios. By analyzing the sensitivity of demand response, heat distribution ratio of gas turbine and the operating state of the system under different carbon trading prices, it is found that reasonable allocation of price-type and substitution-type demand response and heat production ratio of gas turbine is beneficial to improve the operating economy of the system. Making reasonable carbon trading price can realize the coordination of system economy and low carbon.
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Optimal operation of integrated energy systems based on multi-energy complementarity
Статья научная
Complementary multi-energy operation is an inevitable trend in the development of integrated energy systems, and the construction of a fair and reasonable distribution method among multiple stakeholders is the key to realizing complementary multi-energy operation. Integrated energy systems have important applications for achieving sustainable energy development and building a green, low-carbon society, while the complex internal energy structures and equipment coupling relationships pose challenges for their operational optimization. Taking advantage of the interactive and complementary relationship between power and heat on both the supply and demand sides, energy storage devices are used on the supply side to realize the thermo-electrolytic coupling of the combined supply equipment and to enhance the multi-energy supply capacity of the system through each energy conversion device. On the demand side, load types are classified, and the elasticity of electrical loads and the diversity of system heating methods are used to construct a comprehensive energy demand response model with time shifting and curtailment responses of electrical loads and responses of heating load supply methods, and to propose a response compensation mechanism. On this basis, with the objective of minimizing the sum of system operation cost and response compensation cost, the mathematical model for optimal operation of integrated energy systems based on multi-energy complementarity is established, taking into account the equipment operation and dispatchable load resource constraints on both the supply and demand sides. Simulation results and comparative analyses based on arithmetic examples show that: synergistic optimization of both supply and demand, taking into account multi-energy complementarities, can effectively improve the flexibility and operational economy of the system.
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Статья научная
Combined with domestic and foreign literature, the research progress, key parameters and existing problems of flat-panel solar collectors are analyzed. On this basis, the thermal efficiency of flat-panel solar collectors is studied by means of experiments and numerical simulations. This paper introduces and analyzes the structural characteristics of flat-panel solar collectors. Based on the structural characteristics of flat-panel solar energy and research at home and abroad, the influence of the structural parameters of each flat-panel solar collector on the collector performance was studied. According to the heat transfer process and structural characteristics of the collector, the heat energy equation of the collector is established, and the calculation process of the heat loss of the collector is simplified according to the existing research, and the calculation of the heat loss coefficient is an empirical formula. In order to facilitate the experimental study, an efficiency factor and a heat transfer factor are introduced, and the temperature of the fluid at the inlet of the collector is used to replace the surface temperature of the heat-absorbing plate, which is difficult to measure. The calculation program is used to obtain the influence data of each key parameter of the collector on the thermal efficiency and use Origin to process the data to visualize the influence of each parameter on the thermal efficiency. On this basis, a variance analysis method is proposed to optimize the collector. Based on the PYTHON software, the calculation program is written according to the variance analysis method, and the key parameters that will greatly affect the instantaneous efficiency of the collector are combined in pairs, and the optimal collector parameter combination corresponding to the maximum instantaneous efficiency is studied. This research has a certain guiding effect on the utilization of solar energy.
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Optimizing the time costs of passenger transport of people with disabilities
Статья научная
The paper dwells on a mathematical model of the logistical system of transport services for persons with disabilities, and there have been analyzed factors that affect the time spent on their transportation. When developing methodology for optimizing the time costs of passenger transport of persons with disabilities, the following two basic transportation services have been taken into account: “Social Taxi”, which will transport only people with special health; b) vehicle system in combination with urban passenger transport, which will transport representatives of the group of people with restricted mobility together with all other passengers. The study found that in the case of insufficient accessibility to the required environment, by the increase in the demand of disabled people for transportation by “social taxi”, travel costs are increased that results in increasing total costs of the carrier. When determining the expenses of passengers, it is necessary to take into account the additional time, which the disabled persons need for boarding and alighting in buses at the stopping points, on average 2-3.5 minutes.
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Ordering and density amorphous phase of carbon-fiber polymer-matrix PTFE-composites
Статья научная
We studied the application of a mathematical model for calculating the X-ray density of a pure amorphous-crystalline polymer, taking into account the degree of ordering, crystallinity and deformation of a crystalline cell in the amorphous phase, to carbon-fiber PTFE-composites. By comparing the theoretical densities (based on the developed software) of PTFE+CF-composites system with the results of experimental densities and X-ray structural parameters, it was shown that the degree of ordering and density of the amorphous phase of the polymer-matrix PTFE-composites linearly decrease as the content of the carbon-fiber increases. The change in the degree of ordering of the amorphous phase when filler application can be considered as one of the mechanisms of formation of supramolecular structure of composite materials on the basis of amorphous-crystalline polymers.
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Organization of pulsating air flow through a heat exchanger
Статья научная
In recent years, the enhancement of heat transfer by pulsating flow has become a research hotspot. A great deal of work has been done in the past, with remarkable results, to achieve better heat transfer rates. How to improve the efficiency of heat exchanger is always a research topic. In this paper, pulsating air flow is formed by standard ventilation grille and electric actuator, and the pulsating air flow is guided through two-stage heat exchanger to study the influence of pulsating air flow on heat transfer efficiency. The experimental results show that the heat transfer efficiency can be improved by pulsating flow and the heat recovery efficiency can be reduced by increasing the flow rate of the heating medium.
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Overview of research on heat transfer technology for reinforcement of shell and tube heat exchanger
Статья обзорная
The progress made in recent years in the field of reinforced heat transfer technology of shell and tube heat exchangers in China and abroad is reviewed. The energy-saving means and results of improving the heat transfer efficiency of shell and tube heat exchangers are introduced from the experimental research and numerical simulation respectively, and the future research of shell and tube heat exchangers to strengthen the heat transfer technology is also foreseen.
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PLC controlled substation standby power form the input system
Статья научная
This paper introduces the application of Siemens S7-200 PLC in standby power supply. PLC collects the normal running state signal of the primary equipment, which is used as the starting condition and locking condition of the standby power supply automatically input. It realizes different functions through programming to adapt to different running modes. Through PLC and king view in the laboratory, I verified the operation mode. It is also increases the obstacles, enriches the content of the standby self-casting system, and realizes the simulation of the joint adjustment with PLC. It is more obvious to watch the practical application of the stand auto-casting and the diversification of its functions.
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Passive methods analysis of heat transfer intensification of high viscosity fluids
Статья научная
The article analyzes the methods of passive intensification of heat exchange processes. The dependence of hydraulic resistance for fluid flow through the heat exchanger on the value of the temperature head on it is considered. The most effective ways of improvement of heat exchange processes are defined.
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Peculiarities of customs logistics in the case of transportation in the limited space and time
Статья научная
In modern conditions, transport processes encompass not only the movement of goods from suppliers to consumers, but also a large amount of forwarding, information, customs and transactional processing operations on insurance, storage of transported goods. Transport process faces special difficulties, if it is restricted by the scope of border and customs procedures of several countries in the limited space and time. Implementation of modern principles of customs logistics in the practice of customs clearance of transport and goods in the limited space and time will allow us for improving significantly the organizational and economic sustainability of transport processes. The paper examines the trends in the use of customs logistics to simplify customs clearance of vehicles and goods in the case of transportation in the limited space and time.
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Programmable controller based piercing machine system design
Статья научная
The former mainly consists of solenoid valve actuators, sensors, programmable controllers, etc. The core of the hardware design is PLC and related wiring design; the latter is mainly through Protherm V14 to complete the programming, based on the overall architecture of the system to complete the ladder design of subroutines, program flow analysis is the software design is the focus of the final successful design of the electrical control system of the piercing machine. After system debugging and testing, the system has successfully achieved the expected goal and can meet the user's control requirements with simple and clear control logic, which can meet the mechanical piercing process requirements.
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Статья научная
As a representative intrinsic type P inorganic semiconductor material, copper (I) oxide Cu2O has been widely used in photovoltaic, catalysis, chemical industries and other fields, and has an extremely important position. For a long time, the literature on the preparation method and preparation technology of Cu2O is relatively scattered and independent, resulting in a certain degree of obstacles and difficulty in obtaining relevant technical knowledge and understanding its internal principles. Aiming at the progress and innovation of Cu2O preparation methods and technology in recent years, combined with the team’s long-term experience accumulation and research results, this article focuses on the classification, principles and characteristics of Cu2O preparation methods, and the optimization methods and development directions of Cu2O preparation technology. The outlook was carried out. This review aims to provide reference and guidance for the preparation and research of Cu2O and other related inorganic oxide semiconductors.
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Project of building: solar hot water
Статья научная
The rapid development of urbanization in China has led to an increase in high-rise residential buildings, leading to a surge in the construction industry. However, this prosperity has brought about a significant increase in energy consumption, prompting people's demand for alternative energy. As a solution to this problem, solar hot water systems are becoming increasingly popular in China. The following contents need to be considered in the design of solar hot water systems. The general solar hot water system consists of solar collectors, solar water distribution pipes and water storage tanks. The arrangement of the water storage tank and the water distribution pipe is matched with the design of the building, which has great influence on the operation of the solar energy in the building. With the rapid increase in building height and the increase in residents, the roof area has not changed. The architectural layout will have an impact on the absorption performance of solar radiation. Therefore, in order to optimize the use of solar energy, regional planning should be considered. Different solar radiant intensity and different locations of solar collectors will lead to different collection efficiency and hot water supply conditions of solar water heating systems. Throughout the entire process of architectural design, the application of solar energy technology in buildings also requires consideration of the operating area conditions and architectural style, in harmony with the architectural style.
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Among the alternative energy sources, of particular importance is hydrogen energy, which is likely to address the acute environmental problem of large cities in the near future, in terms of pollution of the environment, first of all, of air pollution from vehicles. Among hydrogen-containing raw materials, which can be used in a fuel component, hydrogen sulphide is of particular importance. It is well-known that the Black Sea the largest basin on the planet by the amounts of hydrogen sulphide dissolved in water. In that regard, the Black Sea is the object of the attention of scientists, since its deep waters contain hydrogen sulphide, hydrosuphide and suphide ions in large quantities. The sources of their origin are gases erupted from the volcanic and geological splits existing at the bottom of the sea, as well as organic substances and products of decomposition of microorganisms brought down by the rivers. In this regard, the Black sea may become a potential source of hydrogen energy, and simultaneously that may improve environmental situation in the Black Sea. The paper analyzes the challenges existing in the use of hydrogen obtained from hydrogen sulphide of the Black Sea, as an alternative fuel in the internal combustion engines of vehicles, as well as the prospects for addressing these challenges.
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