Energy-saving Conditions Research Articles

Towards High Surface Area α-Al2O3-Mn-Assisted Low Temperature Transformation.

When impregnated with manganiferous precursors, γ-Al2O3 may be converted into α-Al2O3 under relatively mild and energy-saving conditions. In this work, a manganese assisted conversion to corundum at temperatures as low as 800 °C is investigated. To observe the alumina phase transition, XRD and solid-state 27Al-MAS-NMR are applied. By post-synthetical treatment in concentrated HCl, residual manganese is removed up to 3 wt.-%. Thereby, α-Al2O3 with a high specific surface area of 56 m2 g-1 is obtained after complete conversion. Just as for transition alumina, thermal stability is an important issue for corundum. Long-term stability tests were performed at 750 °C for 7 days. Although highly porous corundum was synthesized, the porosity decreased with time at common process temperatures.

Analysis of Energy-Saving Transport Conditions of Light-Particle Slurry

Ice slurry, as a new environmentally friendly cold storage medium, is widely used in the field of cold storage and air conditioning because of its excellent flow and heat transfer characteristics. Based on experimental data of slurry flow, the rheological properties of light-particle slurries composed of polyethylene particles and water were analyzed using the response surface method. Using the yield stress and viscosity as the responses and considering three key influencing factors (solid-phase content, particle size, and pipe diameter) simultaneously, the order and law influencing the rheological factors were found. This was a new attempt to find energy-saving conditions for light slurry particle transport using the response surface method. The results showed that the response surface method can select the minimum working condition of mixed slurry viscosity and yield stress to ensure the safe and energy-saving transport of slurry. Moreover, it was also found that the main factor influencing slurry yield stress is the pipe diameter, and the yield stress increases with increasing pipe diameter. The main factor influencing slurry viscosity is particle size, and the viscosity increases with increasing particle size.

Design Method of Combined Gradient Dimming Structures for Highway Tunnels

The notable brightness difference between the inside and outside of a tunnel is a major issue restricting the safe driving and energy-saving conditions of highway tunnels. The installation of a shading structure at the entrance of a highway tunnel could resolve this problem. This method is equivalent to moving the entrance zone outside so that light is smoothly transmitted into the tunnel, which is called pretunnel lighting. In this research, the shading structure is selected as the research object. First, the shading effects of pergolas and sunshades of different cross-sectional forms are analyzed. Second, choosing the Jiulongpo Tunnel in Chongqing as an example, through DIALux software modeling and analysis, the tunnel sunshade is selected as the primary shading structure, which is better than the pergola in terms of the average luminance value and uniformity of luminance. Third, based on the idea of gradient dimming outside the tunnel, three kinds of combined gradient dimming sunshades are designed. Considering the influence of the season, weather and orientation, the optimal design scheme is determined in detail. Finally, the energy-saving benefits are calculated of the installation of a tunnel sunshade to replace the enhanced lighting in Threshold zone 1 (TH1) combined with gradient dimming lighting in Threshold zone 2 (TH2). The results show that the combined gradient dimming sunshade in Scheme 3 (70% + 40% + 20% + 10%) is optimal. The combined gradient dimming sunshade could decrease the variation in luminance inside and outside the tunnel and reduce the artificial lighting intensity in the entrance zone, which could facilitate safe driving and energy savings.

Using population algorithms to optimize the temperature regime of roasting phosphorite pellets

The problem of rational energy resource use is especially acute for energy- intensive industries, which include high-temperature processing of mining chemical raw materials (for example, the production of phosphorite pellets from apatite-nepheline ore waste by drying and roasting). In this regard, the temperature modes of roasting conveyor machine should ensure not only the completion of the ongoing chemical-technological processes and the required product quality, but also energy and resource saving. Thus, there is an urgent scientific and practical task of optimizing charge heating modes based on the results of modeling heat and mass transfer processes occurring in various zones of the roasting conveyor machine. The impossibility of carrying out expensive full-scale experiments leads to the need to use computer simulation methods. Nonlinearity, large dimension of the search space, high computational complexity make it difficult to use traditional deterministic search methods. Under these conditions, the stochastic methods that deliberately introduce an element of randomness into the search algorithm show good results. Today, population algorithms based on modeling the collective behavior of living organisms and characterized by the ability to simultaneously process several options have become widespread. To solve the optimization problem, it is proposed to use a modified Cuckoo search algorithm (by introducing fuzzy elements), which provides a comprehensive account of a huge number of parameters set for each vacuum chamber of the roasting conveyor machine. The control of the chemical-energy-technological system for the processing of apatite-nepheline ores waste, taking into account the obtained data and based on the existing neural network model of the high-temperature process, will make it possible to minimize the amount of return and provide energy-saving conditions for the operation of roasting units.

An environmentally stable supramolecular biosolvent: Characterization and study of its potential for the elimination of polar toxic substances in water

Supramolecular solvents (SUPRASs), which are nanostructured liquids made up of non-covalent self-assembled amphiphilic aggregates, are highly promising for the development of engineered green solutions for elimination/reduction of toxic substances in water. However, the reversible and dynamic character of these aggregates have so far prevented the development of cost-effective and scalable strategies. Here, bioSUPRASs made up of non-dynamic assemblies were synthesized from the acid-induced coacervation of rhamnolipids (RLs). These bioamphiphiles contain multiple –COOH and –OH groups, which resulted in RL assemblies with a high intermolecular cohesive force. The synthesis occurred spontaneously, at concentrations of hydrochloric acid as low as 0.01 M, and it took place with high atom-economy (more than 99% of the RL was incorporated into the bioSUPRAS) and under energy-saving conditions (e.g. room temperature). The bioSUPRAS, made up of RL (80 ± 4%, w/w) and water (27 ± 2%, w/w), was environmentally stable, which allowed their direct application to water bodies. This feature, along with the high concentration of RL in the bioSUPRAS (∼840 g L−1) and the mixed-mode mechanisms offered for solute solubilisation, enabled its application to the efficient extraction of highly water-soluble toxic substances (recoveries for ionic dyes were in the range ∼70–100% at fractional bioSUPRAS phase volumes between 0.008 and 0.018). This research shows that highly stable bioSUPRASs can be produced by proper selection of amphiphiles, which should enable the eco-efficient and cost-effective elimination of toxic substances from water bodies.

Synthesis of scheme-cycle designs of absorption water-ammonia thermotransformers with extended degazation zone

The search for new and improvement of existing technical design of energy converter systems for specific consumers requires a reasonable choice of the most rational design for these objects. Thermotransformers that operate on the reverse and mixed thermodynamic cycles, in combination with power plants utilizing renewable and non-traditional primary energy (fuel), are considered to be of interest for small-scale power generation (trigeneration systems), which is consistent with the concept of distributed energy generation. Cold in trigeneration systems is provided by heat-using thermotransformers. This paper reports a method for synthesizing a scheme-cycle designs of absorption water-ammonia thermotransformers that utilize renewable heat sources with a low-temperature potential of 90–250 °С. A "cycle method" was applied to perform the thermodynamic analysis of the cycle of simple absorption thermotransformers with the expansion of the degazation zone with an increase in the temperature of the heating source; the technological schemes for the corresponding cycles have been substantiated. The influence of changing the degazation zone on the energy efficiency of the machine has been established. A scheme-cycle designs of the thermochemical compressor for a thermotransformer with a return supply of solutions to the generator and absorber at " excess temperatures" has been proposed, as a way to improve the cycle energy efficiency. A comparative analysis of the degree of thermodynamic perfection of the considered cycles has been performed using a specific example. The thermodynamic analysis demonstrated that the practical implementation of the scheme-cycle designs "with excess temperatures" could provide energy-saving conditions in small-scale trigeneration systems.

Energy-efficient photothermal catalysis of rubber seed oil for the preparation of biofuel compounds

Fuel components were prepared in this study using rubber seed oil via photothermal catalysis under energy-saving conditions. Modified TiO2 was employed as the catalyst in the catalytic reactions. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray fluorescence (XRF), hydrogen temperature-programmed desorbtion (H2-TPD), CO pulse chemisorption analysis, and UV–vis spectroscopy were employed to examine the microstructure and chemical properties of the modified catalysts. The loading of the catalysts with different active metals considerably reduced the bandgap, leading to enhancements in the absorption of visible light. Temperature, H2 pressure, and reaction time were optimised for the photothermal catalytic reaction via the single factor test. The Pt/TiO2 catalyst realised the highest conversion and selectivity among the tested samples at 120 °C and a H2 pressure of 0.4 MPa for 12 h. Additionally, photo-decarboxylation was confirmed via probing with oleic acid to be the predominant process in the catalytic reaction. This research provides an energy-saving strategy for the preparation of biofuels.

A comparison of PSO and Fmincon methods for finding optimum operating speed and time values in trams

All the studies in urban railways gained importance with the requirement of developing in this area. However, not only technological development but also energy-saving conditions have great importance. One of these efficiency conditions is to know the optimum operating conditions. There are two electronic drive-warning systems. These warning systems are Driver Advisory System (DAS) and Automatic Train Operation (ATO), which are algorithm-based. To enrich these algorithms with meta-heuristic methods provides that it can be adapted to the changing operating conditions. Thus, flexible management can be achieved.
 In this study, the Particle Swarm meta-heuristic and Fmincon which is a nonlinear programming solver in MATLAB methods are used to calculate optimum driving speed, acceleration, cruising, coasting, and full braking times under different operating conditions. Comparative optimization results of these selected methods are presented. Thus, attention is drawn to the efficiency in driving technique with different optimization methods. Specific speed-specific driving time matches obtained can be used to develop innovative driving warning systems.

Bioinspired Electrocatalyst for Electrochemical Reduction of N2 to NH3 in Ambient Conditions.

Industrial ammonia production depends heavily on the traditional Haber-Bosch method at the expense of CO2 emissions and large energy consumptions. Artificial fixation of nitrogen to ammonia is therefore regarded as a promising path to yield ammonia in energy-saving conditions. However, a competent electrocatalyst is highly desired, owing to the extremely stable bond of N≡N. In this work, we report Fe2(MoO4)3 nanoparticles as a non-noble-metal electrocatalyst, inspired by nitrogenase enzymes for electrochemically converting nitrogen into ammonia, which achieves a Faradic efficiency of 9.1% and an excellent NH3 yield of 18.16 μg h-1 mg-1 cat in 0.1M sodium sulfate at -0.6 V vs reversible hydrogen electrode. Also, it has a better ammonia yield rate of 20.09 μg h-1 mg-1 cat in 0.1 M hydrochloric acid. Moreover, this noble-metal-free catalyst exhibits a unique reaction process selectivity and stability compared with the other catalysts working in harsh conditions. The specific reaction processes are analyzed by density functional theoretical calculations to gain insights into the nitrogen reduction reaction (NRR) by this catalyst.

О РАЗРАБОТКЕ ЭНЕРГОСБЕРЕГАЮЩИХ РЕЖИМОВ ВОЛОЧЕНИЯ КРУГЛОГО СПЛОШНОГО ПРОФИЛЯ

О РАЗРАБОТКЕ ЭНЕРГОСБЕРЕГАЮЩИХ РЕЖИМОВ ВОЛОЧЕНИЯ КРУГЛОГО СПЛОШНОГО ПРОФИЛЯ

Application of Phase-Change Materials in Building Energy- Saving and Its Simulation Experiment

This paper simply introduces different phase-change materials according to phase-change ways and phase- change temperature of phase-change materials, such as low-temperature phase-change materials, like water and salts, briefly describes paraffin phase-change materials, such as composition and thermal physical properties of paraffin, analyzes application of insulation materials in building envelope, energy-saving conditions of the building, thermal insulation way of composite wall and energy-saving mechanism of phase- change wall etc. ANSYS is used for numerical simulation of phase-change materials and simulating temperature field of plain concrete slab. After plain concrete slab is heated by heat flow with a stable intensity for a certain time, corresponding charts are given for temperature and heat flow in different time periods. Through numerical simulation by ANSYS, it can know that phase-change materials have good thermal storage effect. In case of usage in the building, phase-change materials are featured in energy-saving and good insulation.

Melting of pellets during arc heating with an analysis of the metal loss in the subelectrode space in a steelmaking bath

The problems of increasing the efficiency of electrosmelting of steel using a system of supplying prereduced pellets through tube (hollow) electrodes are considered. The application of the energy-saving conditions based on the new developed technology is shown to intensify the processes of slag formation and metal heating and decarburization. It is experimentally found that the local supply of iron-ore prereduced pellets under electric arcs into a foamed slag favors a substantial decrease in the dust loss and the metal loss upon melting.

Energy-saving conditions for electric melting of prereduced pellets in the bath of an arc furnace

The problems of increasing the efficiency of electric steelmaking under the application of tubular (hollow) electrodes for supplying iron ore prereduced pellets directly to the high-temperature zone on the surface of a liquid metal are considered. It is shown that the use of an energy-saving regime based on the developed algorithm for the new method of charging pellets makes it possible to decrease the metal losses and to increase the energy efficiency of electric steelmaking.

Strategy of Green Design on Intelligent Energy-Saving Product under Eco-Design Requirements for Energy-Using Product (EuP)

With the threat of global warming nowadays in the 21st century, the European Union has set the standard “Eco-Design Requirements for Energy-using Product(EuP)” for controlling the development of consumptive electronic machinery and products. Therefore, the trend of green design sees the instruction of EuP as the main direction for energy-saving. Considering the factors, undergoing the comprehensive evaluation and development process, the industry needs to draw up the corresponding design strategy in response to the new situation. Therefore, to optimize the green design strategy, the designers can replace hardware with the intelligent system to develop more optimal energy-saving products. Following the ecological instructions of energy-saving of EuP as direction, this study combined the advantage of the intelligent system and green design in order to optimize strategy of green design on intelligent energy-saving product under eco-design requirements for energy-using product (EuP). The evaluation factors were included in the strategies of intelligent energy-saving product design by analyzing the product users’ cognition, needs, habit and etc. Furthermore, through the Fuzzy Analytic Hierarchy Process (FAHP), the priority and the important factors of green design were analyzed. By examining the green design strategy on energy-using product, industry needs to think the energy-saving conditions and the key factors on deciding process. Eventually, the efficiency of product design for environment can be fulfilled successfully.

Motion Tests on a Levitated Body Using a Magnetic Levitation System for Three-Dimensional Motion with Partial Zero Power Control

This paper proposes a partial zero-power controller to move a levitated body under energy-saving conditions using a magnetic levitation device that allows three-dimensional motion. Modeling was specifically performed to control the feedback of each independent x-, y-, and z-direction in a controlled system. The z-direction was controlled by using voltage integration with zero power while the x- and y- directions were manipulated with positioning control. After doing experiments on horizontal displacement on the three points on the x-z plane, we verified that the levitated body smoothly shifted to its required value for the x- and y- directions and it moved with zero-power input voltage toward the z-direction.

Automatic control system for spinning and winding of synthetic fibres

An automatic control system for spinning and winding of synthetic fibres that provides for operation of the electric drive of the metering pumps in conditions of stabilization of the melt pressure and rotation rate of the winder drive was proposed. A laboratory bench that simulates operation of the device for controlling spinning and winding of synthetic fibres based on software provided in a microcomputer was created. A parametric, adjustable, asynchronous electric drive from the KPE series which provides for energy-saving conditions was used for the extruder drive.