Vol 66, No 4 (2019)

Analysis of the state and trends of the world market of lithium-ion batteries (LIB) is carried out, and the main development trends are identified. Until recently, the growth basis of the global LIB market was built on requests related to portable electronics, but the saturation of this market and the formation of new needs in the emerging areas of the automotive industry, industrial generation, and network power distribution have changed the development vector of the entire industry. New needs have made adjustments to key requirements for battery systems and determined new technological barriers. The present work describes and classifies the main LIB electrode components as well as their applicability depending on the field of use of the final product. The state of the Russian market of both final products and main electrode materials is considered. Despite optimistic forecasts for the development of the LIB market in Russia and the expected significant economic effect, the current level of competences, technologies, and production volumes in the Russian Federation does not meet the needs of modern and future markets. In 2017, LIB import to Russia amounted to $85.1 million USD with an annual consumption growth rate of approximately 15–25%. The structure of the battery import is dominated by batteries for consumer electronics. The share of domestic manufacturers in the civil sector is less than 3%, and domestic manufacturers are mainly represented in the special equipment sector. The work presents a list of the main manufacturers of lithium-ion batteries dominating the Russian market. The tendencies to reduce the cost of existing solutions and the possibility of switching to alternative lithium-free metal-ion batteries are considered.

The article presents an anisotropic porous body model in which the transfer anisotropy is taken into account through determining—by means of tensor analysis techniques—the drag force, effective viscosity, and thermal conductivity. The model is intended for describing heat-and-mass transfer in fuel assemblies and tube bundles. For closing the system of anisotropic porous body equations, the integral turbulence model developed by the authors is used. To verify how correctly the hydrodynamics and heat transfer are described, a few hydrodynamic and thermal–hydraulic processes in water- and liquid-metal-cooled fuel rod assemblies are simulated in the anisotropic porous body approximation. The results from simulating the flow patterns of lead–bismuth eutectics in the experimental 19-rod assembly and water in a 61-rod nonheated assembly with its flow cross-section locally blocked in the central and corner parts are presented. The thermal–hydraulic processes in the BREST reactor fuel assembly’s heated 19-rod fragment with its flow cross-section locally blocked in the central part were also simulated using the CONV-3D DNS code in the framework of model cross-verification activities. The numerical analysis was carried out using the developed APMod software module implementing the anisotropic porous body model jointly with the integral turbulence model. It was demonstrated from a comparison of the numerical analysis results with both experimental data and simulation results obtained using the CONV-3D computer code that the APMod software module adequately describes the 3D fields of coolant velocities, pressure, and temperature arising in fuel rod assemblies with a locally blocked part of their flow section. The obtained results testify that the anisotropic porous body model can be used for simulating thermal–hydraulic processes in the cores and heat-transfer equipment of prospective reactors.

The experimental investigation of local hydrodynamic characteristics of the coolant flow downstream of a mixing spacer grid (MSG) in characteristic regions of a Kvadrat fuel assembly in PWRs was performed. The importance of this investigation is due to the fact that MSGs of interest can enhance heat-and-mass transfer. Finding the best design of the grid is required for corroboration of the thermal engineering reliability and operability of the PWR core. The paper presents a description of the test facility and a model of a fuel assembly fragment, the investigation procedure, and discussion of the results. The experiments were performed in the aerodynamic test facility on a scaled model of a fragment of a Kvadrat fuel assembly by simulating the water coolant flow using an air flow according to the hydrodynamic similarity theory. Within the scope of the investigation, the transverse velocity fields in the coolant flow were studied in the characteristic cross-sections of the fuel assembly. The transverse velocity distribution was measured with a five-channel pneumometric probe that can determine the module and direction of a flow velocity vector at an investigated point. The experimental results are presented in the form of distribution of relative transverse velocity downstream of MSG in the characteristic regions of the fuel assembly, such as standard cells, guide channel, and a gap between fuel rods. Based on the experimental data, the coolant flow features have been revealed, and the regularities in the development of transverse velocity field downstream of the mixing spacer grid under investigation have been determined. These experimental data are required for assessment of the mixing spacer grid effectiveness, verification of 3D CFD-programs, and applicable cell-by-cell codes for calculation of a PWR core with a Kvadrat fuel assembly.

The article describes an automated technology put into practice for switching power-generating unit no. 5 at Hrazdan Thermal Power Plant from the combined-cycle plant (CCP) mode to the steam power plant or gas-turbine unit (SPP and GTU, respectively) modes upon an emergency shutdown of the gas or steam turbine. The layout of the power unit based on the waste-gas heat utilization scheme enables the thermal power plant to operate with a partial mix of the equipment, viz., without the gas turbine or steam turbine. However, the initial project did not provide for changing the operational mode without the total shutdown of the power unit. During a sudden shutdown, the considerable unit output of the power unit results in considerable disturbances in the entire electric power system of the Republic of Armenia. The maintenance of a partial capacity of the power unit under emergency shutdown of the equipment reduces unwanted consequences for both the power plant and the electric power system as a whole. A great scope of urgent switching operations and changes in the automatic regulator settings upon sudden shutdown of the gas or steam turbine makes successful actions of the operator under the manual changeover from the CPP mode to the SPP or GTU modes unlikely. Such a changeover can be performed only by the automatics with the operator performing fine correction of the mode upon completion of first-priority switching operations if necessary. The appropriate algorithms for automatic change of the mode when shutting down the gas or steam turbine were implemented in the Automated Process Control System (APCS) of the power unit. In the article, the basic scope and the sequence of actions performed by the automatic devices upon shutting down the gas or steam turbine, as well as the principles of automatic adjustment of the circuits for automated control of the fuel-to-water and fuel-to-air ratios and the temperature conditions of the boiler, are set forth. The article also provides the results of full-scale tests and an example of the behavior of the basic parameters upon shutting down the gas turbine and switching the power unit over to the SPP mode.

Difficulties in implementing methods for unification of design solutions for power-generating boilers of different capacities are considered. The unification of the designs could result in cost reduction at all stages of boiler manufacturing. Approaches are described that were used to search for solutions for two groups of drum-type gas-fired boilers with capacities of 75–150 and 200–320 t/h that function at different values of the superheated steam pressure and temperature. The selection of the design solutions for the boiler-flow diagrams and the method for the arrangement of the burning process common for all boilers, as well as the evaluation of the efficiency and reasonability of the adopted solutions, have been validated. Considering the experience of manufacturing and operating the boilers and the reliability and efficiency of the heating surfaces, the design solutions are set forth and justified, which include the selection of the material of the tubes and their diameters and wall thickness, the number of parallel coils from one cross section, the coil spacing, and the arrangement of the coils. The criteria for determining the geometry of the heating surfaces for the basic boilers of each group have been established. The possibility of extending the geometric parameters on the boilers of other capacities is considered. The variants of the thermal designs for the boilers operating at 100, 50, and 30% loads calculated using the Boiler Designer and Furnace software programs are provided. The causes as to why the required superheated steam temperature cannot be achieved in all boilers at low loads at the excess air coefficients at the furnace exist specified in the current normative documents have been analyzed. Depending on the parameters that determine the arrangement of swirl burners in the furnace, two different but stable burning process patterns are possible.

Federal Law no. 219-FZ of July 21, 2014, “On Amendments to the Federal Law ‘On Environmental Protection’ and certain Acts of the Russian Federation” establishes new principles of environmental policy aimed at significantly reducing the negative anthropogenic environmental impact. Currently, efforts are underway to change over to a system for technological regulation of negative environmental impacts using the best available technologies (BAT). For this purpose, industry-specific technical reference regulations (TRR) on BATs have been developed, the purposes of which are to determine a list of marker (polluting) substances, technological indicators of their emissions, and a BAT list recommended for implementation. In this case, the values of technological parameters for marker substances are determined for various types of fuels depending on the year of the boiler plant commissioning and its capacity. To reduce the emission of TPP marker (polluting) substances, regulation ITS 38-2017 recommends to introduce one or several different practically tested BATs, the total amount of which is pretty large, and their introduction on existing equipment is determined by such factors as fuel type, equipment capacity, required degree of hazardous emission reduction, design features of a boiler plant, etc. When introducing BATs at existing thermal power plants, a real problem arises of choosing efficient air-protection measures with allowance for various interrelated factors, performance characteristics, and specific design and operational parameters of the operating equipment. In this regard, the purpose of this work is to develop an algorithm for the optimal choice of BATs with allowance for a particular TPP. As a result, the algorithm should form a list of BATs recommended for implementation at a particular power unit based on the corresponding initial parameters and select a technology from those proposed by a certain regulation. The developed algorithm will allow environmental and technical services to take into account the variety of factors influencing the choice of BATs as well as to reduce decision-making time, reduce the cost, and improve the efficiency of air-protection measures subject to introduction.

The results of a 20-year-long longevity bench testing of nineteen full-size thermosyphons (TSs) made of steel 20 at a steam-water medium temperature of 240–265°C are presented. For the manufacture of TSs, various methods for processing the inner surface and different compositions of filling aqueous solutions have been used. The thermosyphons were periodically removed from the tests and cooled for monitoring the conditional relative vacuum \({{p}_{{{\text{vac}}}}} = 1 - {{{{p}_{0}}} \mathord{\left/ {\vphantom {{{{p}_{0}}} {{{p}_{{{\text{atm}}}}}}}} \right. \kern-0em} {{{p}_{{{\text{atm}}}}}}},\) where \({{p}_{0}}\) and \({{p}_{{{\text{atm}}}}}\) are the absolute pressure in the steam-gas volume of the thermosyphon and the atmospheric pressure, respectively. The value of \({{p}_{0}}\) was determined using a thermal method described in this paper, which does not require thermosyphon depressurization. After the last inspection of p_vac, four TSs were removed from the tests. The solution contained therein was taken for the chemical analysis of its composition. For the inspection of the inner surface, samples were cut out of the pipes. For the samples of one thermosyphon, metallographic studies were performed to assess changes in the structure and mechanical properties of the pipe metal in the course of hydrogen diffusion through the pipe wall. It was revealed that 16 of 19 TSs exhibit a decrease in p_vac less than 6% during the test period. A high performance was also obtained for TSs manufactured according to the economical technology reported in this paper. The oxygen-free environment inherent in the thermosyphons provide self-passivation of the thermosyphon internal surface with the formation of a protective layer of magnetite. This layer reduces the corrosion rate with releasing hydrogen up to the rate of hydrogen removal via diffusion through the wall of a carbon steel pipe. Retaining the initial vacuum, reducing the wall thickness of the thermosyphon less than by 0.1 mm, and the positive results of metallographic studies confirmed the potentialities of long-term thermosyphon operation with retaining high heat-transfer characteristics and with the absence of hydrogen influence on the structure and mechanical properties of the thermosyphon metal.

A matrix approach to the calculation of heat-and-mass exchangers is used to develop mathematical models of heat-and-mass transfer between water and steam and of dissolved-oxygen desorption from water in jet- or bubbling-type deaeration elements. The area of interfacial surface in the considered elements is determined using well-known methods for calculating hydrodynamic characteristics adapted on a case by case basis considering other influencing factors. The results of the experimental investigation into water deaeration in standard DA-300m and DSA-300 deaerators performed with water sampling from internal elements were used for identification models of heat-and-mass transfer and desorption of dissolved oxygen and development of their empirical support in the form of dimensionless equations for prediction of heat-and-mass transfer coefficients averaged over the interfacial area in an element. Statistical analysis methods were used to find the accuracy characteristics for the derived closed mathematical description of thermal water deaeration in the deaeration elements of interest. The proposed matrix approach to the calculation of heat-and-mass exchangers by creation of a mathematical model of individual deaeration elements was used to construct mathematical models for differently designed deaerators intended for practical important applications. The developed models were used in setting the operating conditions and improving the design of industrial deaerators. The investigations have revealed that the developed mathematical models, together with the empirical correlations as applicable, enable us to determine with an acceptable accuracy the efficiency of water deaeration in designing new or operating existing deaeration units at thermal power stations (TPS) and industrial plants.