Furnace Space Research Articles

TREATMENT OF COPPER FLUE DUST FROM FLASH FURNACE WASTE HEAT BOILER FOR IMPURITIES CONTROL

During the pyrometallurgical processing of copper sulphide raw materials, part of the charge leaves the furnace space together with the exhaust gases in the form of dust entrainment. Volatile components also pass into the dust-gas flow, due to which it is enriched with impurities, some of which are harmful to the technological process. The formed dust-gas flow passes through dust collection equipment, where the main part of it is captured. Most often, the captured dust is recirculated, which leads to a decrease in the productivity of the furnace unit and a gradual increase in the content of impurities in the condensed products of the smelting. To overcome these disadvantages, it is necessary to take part or all the recirculating dust out of the melting cycle and process it independently to extract the valuable metals and dispose of the harmful substances. In metallurgical practice, industrial application for the processing of recirculating dust entrainment has mainly been accomplished by hydrometallurgical methods based on treating the flue dust in aqueous solutions of acid or alkaline reagents. In the present research work, laboratory results on hydrometallurgical leaching of flue dust from a flash furnace waste heat boiler (FF-WHB) are presented. The effect of the main technological parameters affecting the degrees of recovery of the main metals in solution was studied. Based on the experimental results, the optimal conditionsfor hydrometallurgical treatment of the FF-WHB flue dust were determined. By treating the dust under optimal conditions, the main tasks of the research are achieved - removal of impurities harmful to the technological process and reduction of the amount of flue dust processed in the flash furnace.

Analysis of the influence of the type of heat transfer on the dynamics of the ignition processes of wood biomass particles under complex heating conditions

The article presents the results of theoretical and experimental studies of the processes of wood particles ignition under heating conditions typical for furnace devices operating using the circulating fluidized bed technology. The characteristics and conditions of ignition processes under radiation, radiation-convective and radiation-convective-microwave heating are compared. According to the results of the experiments, it was found that the use of microwave energy to accelerate the ignition of wood biomass particles is most effective at moderate temperatures of the combustion medium (at Tg≤870 K). Such conditions, as a rule, are formed in furnace devices that operate using boiling and circulating layer technologies. Based on the results of the analysis of the regularities established in the experiments, a mathematical model of the processes of ignition of a particle of wood biomass under conditions of complex radiation-convective-microwave heating has been developed. Using the method of quasi-stationary "thermal" approximation developed by the authors, an approximate analytical solution of the essentially nonlinear problem of ignition of wood biomass particles under conditions of complex heating is obtained. A comparative analysis of the theoretical and experimental values of the ignition delay time showed their good agreement. The results of the performed studies illustrate the possibility of a sufficiently significant reduction in the ignition delay times of wood biomass particles when using microwave radiation in addition to "conventional" sources of heating fuel particles in the furnace space in the temperature range at which the minimum concentration of anthropogenic nitrogen oxides in fuel combustion products is ensured.

IMPROVED LEVEL OF TECHNOGENIC SAFETY IN PLANTS INTENDED MUNICIPAL SOLID WASTE INCINERATION

Solid municipal waste can be an alternative and renewable type of fuel. Waste incineration provides effective disposal, significant volume reduction and utilization of the energy potential of the carbon waste part. In order to protect the components of the biosphere and service personnel from harmful substances that are formed in the furnace space, it is first necessary to assess the chemical composition and volume of emissions. The purpose of the work is to study the process of burning municipal waste, determine the heat energy obtained, determine the amount of air required for the complete combustion reaction, and determine the volume of flue gases produced as a result of combustion. To achieve the goal of the research, a complex of methods of system analysis and the method of data analysis was applied. An analysis of modern international literary sources, an analysis of the morphological composition of the combustible part of solid household waste, and an analysis of the interaction of chemical substances was carried out. For the research, several components of waste were collected, which were conditionally divided into two main groups - paper and plastic. The first group includes waste, which includes wood, cardboard, and paper. The second group (plastic) includes waste, which includes plastic in the form of scraps of polyethylene film, disposable dishes. As a result of the research, a theoretical volume of combustion products was obtained for the further design of the system of protection of the environment and service personnel from emissions of thermal disposal of solid household waste. Research results can be used in the design of municipal waste incineration equipment. The system of using the heat of flue gases generated after burning waste to dry the waste before feeding it to the furnace is of great importance for saving additional fuel.

Experimental methods for assessing the materials quality of lining for the ship boilers combustion chambers

Autonomous boilers, the most important element of which is the combustion chamber, are widely used in ship power plants. A necessary condition for a high resource of boilers and their trouble-free operation is the high quality of the lining of the furnace space, operating under variable thermal conditions. The quality of the material from which it is made has a decisive influence on the reliability of the lining. The methods of experimental research that can be used to assess the quality of materials for lining the furnace spaces of autonomous boilers are described in the paper. The methodology of conducting research using the method of equivalent materials is presented, laboratory installations for conducting vibroacoustic studies and modal analysis of spectrograms and thermal imaging studies of samples of lining materials are described. As a result of the research, information on the influence of conditions for the formation of equivalent materials samples on their thermophysical properties, spectrograms of the state of brickwork bricks made of various materials, thermal images of lining elements in a stationary temperature field at different locations on the heater is obtained. The results obtained indicate the expediency of using the proposed methods at all stages of the life cycle of autonomous boilers: when designing for a rational choice of lining materials taking into account operational factors, during manufacture and repair during operation to control the quality of materials used and detect hidden defects. In order to increase the effectiveness of the proposed experimental methods for assessing the quality of lining materials of boiler combustion chambers, it is necessary to expand the practice of their use, the accumulation of the results obtained and their statistical processing, which allows us to determine the error of the methods and improve laboratory installations.

ENVIRONMENTALLY SAFE OPERATION OF MUNICIPAL WASTE INCINERATION

The technology of waste incineration makes it possible to solve the issue of obtaining an alternative type of fuel and eliminate the problem of the excess waste in landfills. A multi-stage emission cleaning technology has been proposed to protect the environment and service personnel. The chemical processes that take place in the furnace space have been considered.
 The purpose of the research is to develop the concept of control systems for the technological cycle of the installation of thermal disposal of solid household waste to protection of the environment from these toxic substances: dioxins, carcinogenic hydrocarbons, products of incomplete combustion, in particular, polycyclic aromatic hydrocarbons, nitrogen and sulfur oxides. A complex of methods of system analysis and the method of data analysis was applied to achieve the goal of the research. An analysis of modern international literary sources, an analysis of the morphological composition of solid household waste, an analysis of the interaction of chemical substances, and experimental studies at a research and industrial facility were carried out. As a result of the research, the scientific and applied task of improving the system of protection of the environment and service personnel from emissions of thermal disposal of solid household waste was formulated and substantiated.
 Research results might apply to designing equipment for waste incineration, for choosing rational parameters of the furnace, location of fuel supply burners. General recommendations for the use of chemical properties of harmful substances in the design of cleaning equipment have been provided. The effectiveness of the method of supplying an inert medium (flue gases) to the combustion zone at a temperature below the flame temperature was evaluated. Effective thermal destruction of dioxins is possible in modern waste incineration plants, provided high temperatures, excess air and sufficient residence time followed by a catalytic cleaning. Homogeneous and heterogeneous formation of polychlorinated dibenzodioxins and polychlorinated dibenzofurans formed and released in zones with relatively low temperatures.

OPERATION FEATURES OF ENVIRONMENTALLY EFFICIENT BOILER PLANTS OF MUNICIPAL THERMAL POWER ENGINEERING

The work is devoted to research on the improvement of thermal energy production technologies in gas-consuming heating boiler installations while improving their environmental performance and increasing the operation reliability. The work purpose is to study the heat and humidity modes of the air-supply ducts of boiler plants with exhaust gases recirculation systems into the blown air. The main objectives of the study are: to determine the thermal parameters of a heating boiler with a 2 MW heating capacity with a exhaust gases recirculation system mixed with blown air into its furnace space under conditions of using heat recovery technologies and without them; determination and analysis the heat and humidity parameters of this mixture in different operating modes of boiler plants. Known thermal calculation methods of boiler plants and data from our own experimental studies of heat transfer during deep cooling of boiler plant exhaust gases were used. The thermal calculation results of the heating boiler with a system for exhaust gas recirculation into its furnace space mixed with blown air are presented. The regularities of changes in the adiabatic combustion temperature and heat-humidity characteristics of the above mixture depending on the boiler heat load in different its operation modes during the heating period and the share of flue gas recirculation from 10 to 20 % were established. The research results show that the introduction of recirculation gases leads to a decrease by 150 – 250 °С of the adiabatic combustion temperature tad due to the need to consume fuel heat for heating the introduced ballast and the greater of the recirculation share s the lower the level of the indicated temperature. The research results also showed that gas recirculation causes insignificant (in the range of 0.5 – 4.7 °С) changes in the temperature of the boiler exhaust gases. Based on the data obtained, the change regularities in the heat-humidity characteristics (temperature and dew point) of the mixture of recirculated gases and air in different boiler operating modes during the heating period and under the studied recirculation shares were established. It is shown that recirculation causes condensate formation on the surfaces of air ducts in all operating modes of boiler and in some modes their icing is possible. To prevent these negative phenomena, it is necessary to apply measures to increase the temperature of the gas-air mixture by a value not less than Δtsum = 15 – 35 °С.

Influence of Grinding Methodology and Particle Size on Coal and Wood Co-Combustion via Injection Flame Opening Angle

Today, more than 61% of the world’s electricity is generated by burning fossil fuels. The search for reducing the negative impact of such thermal power plants on the environment does not stop for a minute, one of the solutions to this problem is the partial replacement of coal with biomass. This method has proven itself most effective over the past five years. Co-pulverized combustion of coal and biomass has not found wide practical application, since the processes of grinding, mixing and subsequent spraying of such mixed fuels have not been fully studied. This study compares the influence of the method of grinding, mixing coal and biomass on the processes of spraying mixtures with a change in the pressure of the atomizing air. The results of the research showed that the joint grinding of coal and biomass contributes to the achievement of the minimum size of coal and wood and, as a result, leads to an increase in the opening angle of the torch, which will significantly improve the efficiency of flame combustion in the furnace space at the station. The most effective spray pressure of the mixed fuels was established, which was 3 bar. An analysis of the results obtained during the course of the research allows us to conclude that the mixing of coal and sawmill waste, followed by joint grinding in a ball mill, contributes to the effective grinding of biomass and coal particles to a finely dispersed state, which subsequently leads to a significant increase in the opening angle of the torch at any concentration of the mixture composition fuels.

Energy-ecological assessment of the boiler equipment modernized with the jet-niche technology

The results devoted to the issues of energy-ecological assessment of industrial boiler equipment with jet-niche combustion technology are given in the paper. The basic principles underlying this technology include: rational distribution of fuel in the oxidant stream; stable adjustable structure of fuel, oxidant and combustion products; self-regulation of the fuel mixture composition in the zone of the torch stabilization when the unit load changes. As of today, a large number of industrial gas-burning equipment has been modernized by jet-niche technology, including: boilers, furnaces, dryers, metallurgical facilities, etc. The results of industrial implementation of the technology allowed to accumulate a significant amount of technical information and gave the possibility of preliminary environmental assessment during the modernization of gas combustion equipment. As practice shows, at the present stage the main direction of the technology improvement is to enhance its environmental performance. The influence of the main regime and technical parameters of fire equipment on its emission indicators is established in the paper. Possibilities for reducing nitrogen oxides by primary technological methods, the simplest and most effective of which is the introduction of recirculation gases into the furnace space, have been identified. According to the results of the analysis of emission indicators of the modernized fire equipment with a capacity of 0.5–60 MW, data to estimate the emission indicators of low and medium power boilers depending on the main influencing factors, namely, unit size, excess air ratio and boiler load were obtained. The influence of the introduction of recirculation gases into the furnace space on the level of nitrogen oxides concentration is also taken into account. The efficiency of application of the recirculation gases introduction scheme into the primary air flow in comparison with combustion technologies based on vortex burners is shown. According to the results of the industrial experiment, the energy efficiency of the proposed measures was established on the example of the dependences of efficiency on the load of boilers PTVM-50 and KVGM-20.

Experimental Study to Replicate Wood Fuel Conversion in a Downdraft Gasifier: Features and Mechanism of Single Particle Combustion in an Inert Channel

Downdraft gasification is a promising process of energy conversion of wood biomass. There are such fuel conversion conditions that differ favorably from conventional conditions. In such conditions, there is no pyrolysis zone in the fuel bed, which precedes the oxidation zone. Fuel is supplied into the oxidizing zone without charring, where it reacts with the intensive cold air flow from tuyeres. The study aims to replicate the conversion of particles in a gasifier close to tuyeres. For this purpose, the individual particles are burned in the muffle furnace space and the quartz channel replicating presence of other bed particles at a first approximation. In the experiment, the furnace temperature was varied, as well as the velocity of air supplied to the particle. Two-stage and single-stage mechanisms of particle combustion were identified. A two-stage process is observed in the range of tuyere velocities below 20 m s−1. The two-stage mechanism is characterized by a stage of devolatilization and volatiles combustion, followed by a stage of char residue combustion. The stages are predominantly separate from each other, and their degree of overlapping is low, amounting to 24%. At the tuyere velocities above 125 m s−1 combustion of particles is realized primarily as a single-stage process. The intensive air flow reaches the fuel particle surface and initiates combustion of the surface char layer. In this case, the stages of devolatilization and char residue combustion run concurrently for the most part. In the single-stage mechanism, the degree of stage overlapping is significantly higher and amounts to 60–95%. For the two-stage combustion mechanism, the effect of cyclic movement of the flame across the particle surface is evident. The number of cycles can reach eight. This effect is due to the change of conversion stages. At air velocity above 95 m s−1, fragmentation of fuel particles commences. A layer of char formed at an initial stage of burning heats up in the intensive air flow and is separated from the particle surface. The heated walls of the quartz channel contribute to the intensification of particle combustion. This effect is probably due to the swirling of the flame between the wall and the particle surface.

Analysis of modern theoretical and technlogcal methods and equipment and prospects for the development of loading of blast furnaces

The current state of analytical support of blast furnace technology is considered. The main methods developed by leading research and design organizations in metallurgy, which are used for effective management of blast furnace smelting, are analyzed. It is shown that the loading technology of the blast furnace is of crucial importance for the efficiency of iron production. Monitoring equipment for modern blast furnaces allows you to obtain a wide range of information that can be used for prompt and effective correction of blast furnace smelting. The use of the specified information provides ample opportunities to ensure the most rational technical and economic indicators of the iron smelting process. In this regard, considerable attention was paid to the features of equipment and technology for loading batch materials into the furnace. The main operating characteristics for the equipment of blast furnaces, which ensure the loading of charge materials in the angle of ensuring the rational circumferential and radial distribution of the charge on the blast furnace, are considered. This, in turn, makes it possible to adhere to the specified loading program and ore loads. A description of how to load using a coneless tray-type loading device is provided. The process of movement of the flow of charge materials along the paths of the coneless loading device is analyzed. Sections of the guide shafts, section of the movement of the charge in the blast furnace space are considered separately. Disadvantages and advantages of the existing methods of calculating the dynamic parameters of charge materials at the relevant sites are revealed. The description of the sequence of operation of the equipment, which ensures the charging of the blast furnace charge, and recommendations for increasing the efficiency of the algorithms of the aggregates are given. The methods for determining the geometric and dynamic parameters of the movement of charge materials in the case of their release from the storage hoppers of the loading device of the blast furnace are considered separately. Analytical dependences are given for determining the flow of charge materials from the outlet and the charge leakage rate. The process of formation of a charge column in a blast furnace is considered. Among the main factors affecting the formation of the necessary ore load along the radius of the blast furnace, the loading program and the granulometric composition of the charge materials supplied to the blast furnace are highlighted. It is also shown that the most effective loading of the blast furnace with charge materials is considered to be the following method, when used, the optimal value of the ore load is ensured while ensuring the necessary gas permeability of the column of charge materials. In thisway, the main directions of effective improvement of the blast furnace smelting technology to ensure the best technical and economic indicators and a significant reduction in the specific consumption of raw materials have been determined.

Research of thermotechnical characteristics of domestic boiler with a mechanical pellet burner

An experimental study of technologies for direct combustion of pellets in a domestic boiler was conducted. Experimental studies to determine the thermophysical characteristics of the process of burning pellet fuel in the bulk layer were performed using a pellet burner Pelletron-15.To determine the patterns of the process of burning pellets in the burner and the thermal characteristics of the domestic boiler with a pellet burner, studies of the temperature of the boiler volume at different modes of operation of the burner were performed. Temperature measurement was performed using HA-thermocouples with open junction, located in the furnace space at different heights and different distances from the initial cross section of the burner. The analysis of the chemical composition of flue gases, which was determined using a gas analyzer TESTO 330-2LL, namely determined the temperature of the flue gases at the measurement point, as well as the concentration of oxygen (O2), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx) and other parameters.According to the results of experiments, the temperature distribution in the furnace space of the solid fuel boiler Viadrus with a thermal capacity of up to 24 kW with a mechanized burner Pelletron-15 with a pellet feed hopper built into the front panel was determined.In addition, based on the results of some experimental studies, the heat of combustion, humidity and ash content of pellets were determined. The dependences on the time change of the boiler temperature at the stage of quasi-stationary mode of wood pellet combustion are obtained: at the minimum and maximum fuel supply from the hopper, as well as at the maximum fuel supply mode after the supply of additional air from the fan and in the pellet combustion process.The influence of speed and temperature of air introduced into the combustion chamber was determined. According to the research results, measures are proposed to improve the design characteristics of the pellet burner in low-power boilers (10…30 kW).

FEATURES OF ALUMINUM DISC PRODUCTION TECHNOLOGY

The technology features of cast aluminum discs production in the conditions of «Vector» LLP are presented. Aluminum alloy AK-12 smelting process in induction crucible furnaces is described in detail. Results of industrial experiments conducted to reduce the melting time are presented. Initially, the task was set to find the optimal permissible metal residue (swamp) in the furnace after the melting was drained. Based on the results obtained, the optimal mass of the swamp was revealed to be 100 kg. A series of experimental melting was also carried out in order to identify the difference in the melting duration of the heated billet and the billet at room temperature. In the conditions of production of the enterprise «Vector» LLP, a reduction in the duration of melting by 25 minutes was achieved by using the melting method «in the swamp». Also, the preheating of charge materials in the space of the heating furnace contributed to the reduction of the melting time by 10–15 minutes. Before making changes to the technology, a maximum of 12 melts were carried out per day, taking into account the time for cleaning the furnace crucible and the process of draining metal from the furnace space. After the changes were made, the melts number and volume being metal smelted increased almost twice. This allowed the company to simultaneously put into operation four casting machines, which are supplied with metal by only one induction furnace with a capacity of 700 kg.

Аналіз газодинамічної роботи колошникового простору та тракту «доменна піч – пиловловлювач» при зміні конструкції газоходів

Аналіз газодинамічної роботи колошникового простору та тракту «доменна піч – пиловловлювач» при зміні конструкції газоходів

Study of selected properties of the 98W-1.4Ni-0.6Fe heavy tungsten alloy

The aim of the work was to determine the density and tensile strength Rm of the sintered rod measured in selected places along its axis. The test rod with the composition of 98W-1.4Ni-0.6Fe was produced by powder metallurgy and sintering with the participation of the liquid phase. The performed measurements showed that the density of the samples depends on the place where the sample was taken from the bar and the amount of the outer layer removed by rolling. The densities of samples taken from the ends of the bar are higher than those taken from the center of the bar. The lowest density was obtained for ready-made strength samples. The performed measurements showed that for several samples the results of density and strength Rm are correlated. Gradually decreasing sample density translates into a decrease in their tensile strength. The lower density of samples from the central part of the bar can be related both to the linear shrinkage occurring during the process, as well as to the non-uniform temperature distribution in the sintering furnace space.

ТЕХНІКО-ЕКОНОМІЧНЕ ОБГРУНТУВАННЯ ДОЦІЛЬНОСТІ РЕКОНСТРУКЦІЇ ТРИФАЗНОЇ ДУГОВОЇ СТАЛЕВАРНОЇ ЕЛЕКТРОПЕЧІ

The technological units of electric arc steel remelting are among the most energy-intensive consumers for whom the problem of energy saving is extremely urgent. The proposed reconstruction of the electric-arc steel furnace is aimed at reducing the amount of electricity consumption. The feasibility study makes it possible to assess the technical and economic parameters of project of an electric-arc steel furnace reconstruction. The simulation results of the reconstructed electric furnace showed that due to the optimal placement of electric arcs in the electric furnace space, the duration of the metal melting stage can be reduced by approximately 19 min. Cost-effectiveness calculations for the implementation of the innovative solution showed that reducing the duration of steel remelting in a reconstructed furnace reduces the electricity consumption by approximately 28% per process. The article takes into account only the reduction of electricity consumption, but does not take into account the possibility of improving the productivity of the furnace by increasing the number of technological processes per shift. References 7, figures 3, table 1.

Damage analysis and assessment of the impact of damage on the operation of supporting structures of oil refining tube furnaces

Relevance. Due to the widespread use in practice, tubular furnaces were chosen as the object of study of this work. The article provides an analysis of damage to the supporting structures of oil refining tubular furnaces. The causes of damage and the physical nature of the development of damage are established. According to the results of field surveys, it was found that about 10% of the furnaces are operated with damage in the form of significant curvature of the supporting structures that developed as a result of the explosion of the gas-air mixture and the technological product inside the furnace space. The aim of the work is to analyze the damage and assess the impact of damage on the operation of the supporting structures of furnaces. Methods. The main research results were obtained by static numerical analysis of spatial models of furnace frameworks in the LIRA-SAPR software package. This complex belongs to the class of software products that implement the finite element method. Results. According to the results of calculating a series of models of structures, the effect of damage on the operation of the supporting structures of the furnace is determined. Based on the analysis of calculation data for models of tube furnaces with damage and comparison of calculation results for furnace models with structural damage identified during the survey, ways to optimize the design decisions of an industrial furnace are determined. Studies have shown the need to improve the design of tube furnaces in the direction of improving technology and improving the structural form of the supporting frame of the furnace.

Effect of concentration and relative position of wood and coal particles on the characteristics of the mixture ignition process

This article presents the results of experimental studies of the ignition of composite wood/coal fuel particles under high-temperature heating, corresponding to the internal furnace space of boiler units of thermal power plants. The ignition of a wood-coal mixture was studied based on coal and wood waste widely used in energy.For the first time in world practice, the basic regularities of the joint ignition of a group of wood and coal particles located at a certain distance from one another have been experimentally established. The ignition delay times (tign) of each fuel particle in the group are determined. The influence of the concentration of wood and the relative position of the fuel particles relative to each other on the characteristics and conditions of ignition is analyzed. It was shown that in the temperature range Tg = 873–1273 K, the gaseous products of wood pyrolysis begin to burn first, the coal particles burn second. In this case, the time interval between the ignition of wood and coal does not exceed 1 s, with a distance between particles of up to 10 mm.According to the results of experiments, it was also found that the optimal component ratio in the wood/coal system lies in the range from 30/70 to 35/65. It is shown that at a high concentration of coal in the wood-coal mixture, coal particles act as a kind of screen that blocks thermal radiation from the external environment to the wood particles.

Investigation of the movement of charge materials in the tray-distributor of the cone-free loading device of the blast furnace

Objective.Determine the analytical dependence of the profile of granular materials moving on the tray-distributor of the cone-free loading device on the length coordinate. Method. Kinematic and geometrical regularities of movement of charge materials on the distributive body of the cone - free loading device of tray type are considered. It is shown that the dynamics of the flow of charge materials is significantly influenced by such factors as the value of the average particle diameter of the loaded material, physical and mechanical characteristics of the charge, its flow rate, angular velocity of the distributor tray and its angle. Results. The analysis of the obtained results makes it possible to calculate with sufficient accuracy the rate of charge rise from the tray-distributor in the furnace space of the blast furnace. This makes it possible to calculate the trajectory of the charge flow in the furnace space and to obtain the coordinate of the intersection of the trajectory with the surface of the charge backfill on the blast furnace grate. The obtained equation of the profile of the movement of charge materials on the tray-distributor makes it possible to recommend the position of the tray when loading the blast furnace, which prevents the transfer of the charge through the edge of the tray. Scientific novelty. A new method for solving the Cauchy problem for a differential equation describing the flow of a charge through a distributor tray is proposed. It is established that the change in the flow rate of charge materials passing through the tray-distributor significantly affects the configuration of the surface of the charge on the tray, and this, in turn, causes a change in the rate of flow into the furnace space. Studies have shown that the motion parameters are significantly affected by the initial height of the charge materials on the tray. Practical significance. The obtained results allow analytical calculation of the change in the dynamics of the charge movement under the condition of a constant angle of inclination of the tray of the loading device of the blast furnace. This makes it possible to expand the possibilities of automatic correction of the gas dynamics of the blast furnace zone in specific charge conditions.

Numerical study of residential Smart Dual Fuel Switching System (SDFSS) with on-site solar photovoltaic system

Building energy consumption accounts for approximately 36% of total energy consumption in the world. Since buildings are capable of on-site electricity generation and exhibiting predictive pattern of heating and cooling, the focus of this study is to investigate the Smart Dual Fuel Switching System (SDFSS), comprising a natural gas furnace and an air-source heat pump (ASHP), working in conjunction with on-site solar photovoltaic system. Base-case scenario using 1.5-ton rated capacity ASHP with 8.5 heating seasonal performance factor (HSPF) yielded only 4% cost savings and 15% greenhouse gas (GHG) emission reduction when compared to natural gas furnace space heating scenario. With an ASHP of 2-ton rated capacity and HSPF of 10 working in conjunction with solar photovoltaic (PV) system of 4.08 kWp, the cost savings of SDFSS increased to 12% and the GHG emissions reduction of 45%. SDFSS integrated with the grid is expected to yield significant benefits. It can help avoid situation of buildings drawing electricity all at once and reduce the overload on the grid. Also, it can redirect electricity generated from the solar PV system of a building for which using natural gas furnace is more economical to a building whose space heating demands can be met with this excess electricity. Higher ASHP performance and capacity, higher carbon pricing, and higher solar PV electricity generation will lead to the design of a more economical and sustainable SDFSS.

Influence of filtration heat transfer on parameters and conditions for ignition of coal-water fuel particles

The paper describes a theoretical study on the influence of filtration of a mixture of gaseous products of pyrolysis and water vapor on the dynamic of ignition of coal-water fuel particles under conditions of high temperature heating. The developed mathematical model offers simulation of the process of ignition of coal-water fuel droplets under conditions close to the furnace space (characterized by intense radiation-convective heating) in typical boilers. Comparisons of experimental data (found previously) and simulation data on the ignition delay time (tign) demonstrate good compliance. Simulation results show that filtration of water vapor and volatiles is a significant factor (influence up to 40 %) affecting the characteristics and conditions of ignition of coal-water fuel droplets. The higher velocity of the vapor-gas mixture flow through the porous structure of the fuel particle results in a longer ignition delay. The effect of using the “simplified” model of filtration heat transfer on the prognostic estimates of coal-water fuel ignition is analyzed. It is demonstrated that using of rather simple models for filtration heat transfer does not bring any significant errors in calculating the ignition delay time.