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Torrefaction is considered as a method for producing biofuels with improved characteristics compared to those of the “raw” biomass (higher calorific value, moisture resistance, better grindability). The torrefaction process is an endothermic process that is usually carried out in a gaseous atmosphere in the absence of oxygen. To reduce the required heat input, it is proposed to employ the oxidative torrefaction and conduct the process in a fluidized bed agitated with flue gases containing less than 6% oxygen. Preliminary studies of the oxidative torrefaction of sunflower husks, including thermogravimetric analysis of the treated material, have shown that the heat treatment time for the biomass should be at least 5 min. A fluidized bed is a reactor with ideal mixing of the treated material where uniform treatment of raw material particles cannot generally be attained. To overcome this disadvantage of the fluidization technique and achieve the required residence time for biomass in a fluidized bed during a continuous torrefaction process, it was proposed to equip a torrefaction reactor with a series of vertical baffles spaced at 50 mm. These baffles induce a loop-like flow of the processed biomass from the inlet to the outlet of the reactor. To investigate the residence time for husk particles in the reactor, a tracer, which was colored to husk particles' color with a water-soluble dye which did not change the weight and size of the particles, was injected into the bed of uncolored particles. Tracer samples were taken every 30 s at the outlet of the reactor and were analyzed using a special procedure to determine the fraction of colored particles in each sample. This enabled us to gauge the time during which the colored particles injected into the fluidized bed reached the point of their discharge from the bed. Studies performed in a “cold” model of the reactor showed that a series of vertical baffles in the bed can provide the required residence time for biomass in a reactor including commercial reactors. Plates can provide the necessary biomass residence time in the reactor.

Abstract An ideal tracker which follows the sun both north-south and east-west is designed and constructed. It is suitable for mounting a linear concentrator, focusing parabolic concentrator or photovoltaic array of aperture area 2 m2. The apparatus is built with two axes equational mount and controlled by a microprocessor system. The tracking is carried out by utilizing the astronomical coordinates of the sun. As such the present system gives improved tracking capability over the conventional sensor controlled tracker systems. The performance of the tracking system was studied with photovoltaic array mounted on it and tracking error of less than one degree was achieved. This tracking error can be reduced further by proper software.

The Internet of Things (IoT) provides opportunities to control interconnected smart devices via pre-designed scenarios with littleor no human involvement. Due to the need for systematic improvement of industrial energy efficiency, the relevance of IoT-based energy management systems (EMS) is constantly increasing. Industrial IoT (IIoT)-enhanced EMS are created to support the digital transformation of enterprises. They increase the transparency of energy consumption statistics, enhance the personnel awareness of energy losses, provide predictive analytics tools for forecasting potential industrial accidents and future energy demand. This paper hence provides a system architecture of the energy management assistant that can be used at enterprises to archive the aforementioned aims. Authors identify the relevance of EMS, list the conditions at modern enterprises that define the requirements for the energy management assistant, demonstrate the identified requirements in the UML diagrams. Specification of energy planning and energy monitoring stages demonstrate the possibilities of the designed system architecture. For demonstration purposes, authors present examples of linear and nonlinear regression models implemented to specify energy consumption target functions based on real data. Finally, future research directions and open energy management problems are presented. The analysis has been carried out within the priority area of scientific development established in the National Research University Higher School of Economics - "Research on control methods in Cyber-Physical Systems".

Special linking circuits are required for the design of safe railway automation and remote control of trackside objects. They are usually based on devices with an asymmetrical failure rate, mainly first reliability class electromagnetic relays. The development of railway automation and remote control devices requires the use of state-of-the-art contactless semiconductor components. In this case, the use of functional converters or periodic testing of semiconductor switches and disconnection of the power supply from control objects in case of faults are needed. This article describes the use of a three-phase induction motor as the solution of the problem. They are used for the design of functional converters for railway automation electric motors control. It is proposed to use the low-frequency mode of power switch operation (switch frequency is 50 Hz) and to abandon the pulse-width modulation. The suggested technical solution is used in a CBI-MPC system for train traffic control at stations developed at the Center for Computer Railway Technologies of St. Petersburg State Transport University.

AbstractNowadays, researchers are focusing on the methods of using recycled industrial/agricultural wastes as raw materials, which are not only economically but also environmentally useful. In the recent years, many scholars have conducted research on the rational use of rice husks (RHs) and found that RHs are rich in inorganic/organic components and used in combination with the certain building materials to produce new green composite building materials. This paper studies the method of using RH processed products and the sodium silicate solution (liquid glass) made from RH ash to produce cheap wood substitute composite materials, which can be improved the insulation performance of the wall greatly. Obtained results are determined by comparing with the properties of standard polymer composite materials such as particleboards, chipboards, and medium‐density fiberboards (MDF). The significance of the work is pointing out by solving the problem of recycling large‐tonnage agricultural waste and reproduce products with the consumer's value.

Abstract This study presents and evaluates the feasibility of a novel hybridization of modified Kalina cycle, reverse osmosis desalination, and low-temperature water electrolysis utilizing geothermal energy to yield power, distilled water, and hydrogen, respectively. The scientific impact of the current work has been improved considering the features of Sabalan flash-binary geothermal wells in Iran as a real model through a case study. In addition to designing a novel setup, the smart use of multi-heat recovery technique, modifying the base cycle, and utilizing a part of generated distilled water to produce hydrogen by the electrolyzer are the other structural originalities, distinguishing the current work from the previous studies. The suggested system is scrutinized via a parametric study and optimized based on a genetic algorithm. The parametric study demonstrated that the highest sensitivity of varying the performance criteria of the whole system is attributed to the change in flash tank pressure. Moreover, the multi-objective optimization led to achieving the exergy efficiency and trigeneration gain output ratio as 51.3% and 1.7 for the system, respectively. Furthermore, the system was able to produce 4795 kW of power, 5.3 kg/h of hydrogen, and 19.9 kg/s of distilled water.

A numerical method of calculating the neutron yield of accelerator neutron generators using the nuclear reactions D(d, n)3He and T(d, n)4He and results are presented. For a generator with a titanium target, the neutron yield is presented for different accelerating voltages and ratios of the ion-flux components and approximate relations suitable for real-time evaluation of the neutron yield are obtained.

Abstract Electronic properties of benzothiadiazole (BTD) unit containing dyes adsorbed on TiO2 nano-particles have been estimated using Quantum Theory of Atoms in Molecules (QTAIM). We found that short circuit photocurrent density Jsc and open circuit photovoltage Voc of the studied DSSCs are well related to the electronic properties of dyes, namely charges of BTD atomic basins of nitrogens, summary isodensity surface area and summary volume of hydrogen basins. Analysis of deviations of predicted and observed photovoltaic properties allowed to reveal device fabrication details influencing positively and negatively on device efficiency. Found relationships have been used for design of new promising dyes and recommendation of the better fabrication details of DSSCs with significantly higher photovoltaic properties as compared to the studied and published. For newly designed metal-free BTD-unit containing dyes, Jsc is expected to reach 20.7–25.8 mA/cm2, Voc – 0.858–1.029 V and power conversion efficiency η – 10.6–16.3%.

Abstract One factor that significantly limits blade service life and reliability in GT-100 power turbines is sulphide-oxide metal corrosion of guide and rotating blades. Application of coatings is the most efficient method to prevent corrosion failure. An electron beam physical vapour deposition CoCrAlY coating is used for high and low pressure turbine first-stage rotating blades made from E1 893 alloy. Studies of CoCrAlY-coated blades after different service periods (from 390 to 5900 h) showed that this coating most efficiently protects rotating blades in turbines which operate in northern regions of the country. Because of low temperature hot corrosion leakage, corrosion failure is observed in turbines operating in southern regions of the country. In order to improve corrosion resistance, a ceramic coating has been developed. These coatings increase the endurance of equipment and make it possible to save energy.