Electric Heating Furnace Research Articles

Reproduction of decarburization caused by overheating in fire tube boiler material

One of the non-destructive testing methods for analysing fire tubes is the replica technique. This technique allows the investigation of microstructure, cracking, and high-temperature creep under operational circumstances without the cutting of the components. A cellulose-acetate foil was used to make a copy from the topography of the surface, which was suitable for microscopic analysis. In this paper, decarburization was generated in P355N fire tube material. The aim of the reproduction was to investigate the effect of overheating in boilers. The decarburization of the fire tube was made at different temperatures (300 – 900 °C) in an electric heating furnace. General deterioration and decarbonization began at 700 °C. A preliminary step of the decarburization was the transformation of the pearlite, which can be easily detected by scanning electron microscope. Grain growth could not be observed, and the particle size was unrelated to the thickness of the decarbonized layer.

Temperature control in electric furnaces: Methods, applications, and challenges

Temperature control of electric heating furnaces, a common piece of equipment in industrial production, is essential for assuring product quality and enhancing production effectiveness. In order to better understand the similarities and differences in temperature management between various types of electric heating furnaces, this paper first discusses the fundamental concepts and classifications of electric heating furnaces. Following that, it systematically describes the applications of the various temperature control techniques now used for electric heating furnaces, such as PID control, fuzzy logic control, genetic algorithm control, and model predictive control. This paper further analyzes the difficulties in controlling the temperature of electric heating furnaces and identifies potential future development trends in light of the issues that currently used control methods must deal with in practical applications, such as insufficient control accuracy, slow response speed, and poor stability. Finally, it summarizes the information in the entire paper and considers the direction of temperature control research for electric heating furnaces. This research will focus on new control theories and algorithms, furnace body design optimization, control system integration, and intelligent adaptive temperature control. In order to advance the development and advancement of technology in this area, the goal of this article is to provide a thorough theoretical reference and practical advice for the temperature management of electric heating furnaces.

A Temperature Control Method of Electric Heating Furnace Based on Fuzzy PID

The traditional PID control method has a series of problems such as overshoot or static error. This paper takes the electric heating furnace temperature control system as the background, combines the fuzzy algorithm to design the fuzzy PID system, and uses the MATLAB fuzzy control box to set up the fuzzy reasoning system and the fuzzy rule table., and use the Simulink platform to build the temperature control system simulation model of ordinary PID and fuzzy PID, and verify the influence of parameters on the system.

Logic adaptive optimization model for dynamic temperature compensation of heating furnace based on proportion‐integral‐derivative position algorithm

AbstractIn order to improve the adaptive compensation control ability of the furnace dynamic temperature compensation logic, an adaptive optimal control model of the furnace dynamic temperature compensation logic based on proportion‐integral‐derivative (PID) position algorithm is proposed. Firstly, the constraint index model of the dynamic compensation logic control of the heating furnace temperature is constructed, and the target structure analysis of the electric heating furnace temperature control is realized by using the PID control mode. The platinum resistor is used to collect the temperature in the feedback link, and the controlled equipment converts electrical energy into heat energy for release. As the temperature rises, the difference between the two is sent to the fuzzy controller. The model fuzzy controller outputs an analog value, and the PID control system outputs different control parameters, thus realizing the parameter analysis and optimization design of the control law of the heating furnace temperature dynamic compensation logic control. The test results show that the method has good accuracy, with an error of 0.01 to 0.02, and has certain application value.

Analysis on overall energy efficiency and flexibility of thermal integrated energy system

In order to solve the problem of energy consumption, improve the efficiency of energy utilization and develop new energy, the total energy consumption and fluctuation of thermal integrated energy were analyzed. Four suggestions are put forward for the integrated power system of flexible thermal power plant, namely, electric heat storage system, electric heat pump heat storage system, g, heating system and high pressure heating system via steam turbine, which can improve the air energy consumption capacity of the system and reduce the total coal consumption of the system. Among them, in the case of small air conditioning units or small air conditioning units do not use electric heating furnace and electric heat pump furnace. Heat storage technology of thermal power unit is not suitable for daily exhaust. In contrast, the high pressure/IP bypass heating process of steam turbine is more flexible and less restrictive, which is the best method for comparison. Compared with other schemes discussed by the author, this scheme has the highest flexibility and the least restrictions, and is the best one among the four.

Electrified steam cracking for a carbon neutral ethylene production process: Techno-economic analysis, life cycle assessment, and analytic hierarchy process

Electrification is regarded as one of the solutions for decarbonization. To reduce the emissions of carbon dioxide from the steam cracking which is a conventional ethylene production process, the electrical heating furnace can be applied to the steam cracking called the electrified furnace. Here, to determine whether the electrified steam cracking is proper for carbon neutrality, the techno-economic analysis, life cycle assessment, and the analytic hierarchy process were implemented. The analysis was proceeded by the fourteen cases divided according to steam cracking, electrified steam cracking, and seven electricity generation methods. As a result, considering the technology development level, economic feasibility, and environmental impact, the best case was the steam cracking with hydropower, and the electrified steam cracking with hydropower, solar power, and wind power had high potential. As improving the technology development of the electrified furnace, the electrified steam cracking can be expected to become the proper ethylene production process to achieve carbon neutrality.

Operation optimization of a solar collector integrated with phase change material storage heating system

Making full use of renewable energy for building heating is inevitable if energy structures are to be transformed and emissions are to be reduced. A solar collector integrated with a phase change material storage heating (SC-PCM) system is a promising distributed building heating technology. However, the feasibility and economic efficiency of the system in practical applications have rarely been studied. In this study, on-site measurement and model development for a SC-PCM system constructed for a three-storey office building in Tianjin were carried out. The accuracy of a self-developed phase-change heat transfer module, Type 668, and of a TRNSYS simulation model was verified by data from a 45-day on-site measurement. The mean relative error (MRE) of the on-site measurement and simulated data for the heat supply of the phase-change module was 7.8%. The MREs for indoor temperature and total daily heat supply of the entire SC-PCM system were 2.2% and 8.3%, respectively. The verified model was then used for a system-optimization study. Nine control strategies designed by the orthogonal method were compared, and it was proved that the control strategy VI (3-WV conversion condition: T3 < 43 °C close, T3 > 48 °C open; 3-PDV set value: 36 °C; EHF heating period: 23:00–5:00) is the optimal strategy for the current SC-PCM system. The energy consumption of strategy VI was 21,470 kW·h for 28 days, 21.4% less than that of the original strategy. A four-factor, three-level orthogonal design test was conducted to determine the effects of various parameters on a nonspecific SC-PCM system. It was concluded that the area of the solar collector (SC) has the greatest impact on indoor temperature, while the power of the electric heating furnace (EHF) has the greatest impact on the levelized cost of heat (LCOH). The TRNSYS model was used in combination with optimization solution tool GENOPT to obtain the optimal parameters of the system for different cities in China. The LCOHs in Tianjin and Shenyang were 16.4% and 17.5% lower, respectively, than the local flat electricity prices. It was demonstrated that the system has great application potential in areas with high heat demand and a significant peak valley power policy.

Pyrolysis and Oxidation of Waste Tire Oil: Analysis of Evolved Gases.

Valorization of waste such as waste tires offers a way to manage and reduce urban waste while deriving economic benefits. The rubber portion of waste tires has high potential to produce pyrolysis fuels that can be used for energy production or further upgraded for use as blend fuel with diesel. In the preset work, waste tire oil (WTO) was produced from the pyrolysis of waste tires in an electric heating furnace at 500–550 °C in the absence of oxygen. Pyrolysis (in nitrogen) and oxidation (in air) of the obtained WTO sample were then performed in a thermogravimetric (TG) furnace that was connected to a Fourier transform infrared cell where the evolved gases were analyzed. The WTO sample was heated up to 800 °C in the TG furnace where the temperature of the sample was ramped up at three heating rates, namely, 5, 10, and 20 °C/min. The TG mass loss and differential thermogravimetric mass loss plots were used to analyze the thermal degradation pathways. Kinetic analysis was performed using the distributed activation energy model to estimate the activation energies along the various stages of the reaction. The pollutant gases, namely, CO2, CO, NO, and H2O, formed during WTO oxidation were evaluated by means of the characteristic infrared absorbance. The functional groups evolved during pyrolysis, namely, alkanes, alkenes, aromatics, and carbonyl groups, were also analyzed. The obtained information can be used for the better design of gasifiers and combustors, to ensure the formation of high-value gaseous products while reducing the emissions. The utilization of waste tires by producing pyrolysis oils thus offers a way of tackling the menace of waste tires while acting as a potential energy source.

Robust adaptive active disturbance rejection control of an electric furnace using additional continuous sliding mode component

The temperature control process of electric heating furnace (EHF) systems is a quite difficult and changeable task owing to non-linearity, time delay, time-varying parameters, and the harsh environment of the furnace. In this paper, a robust temperature control scheme for an EHF system is developed using an adaptive active disturbance rejection control (AADRC) technique with a continuous sliding-mode based component. First, a comprehensive dynamic model is established by using convection laws, in which the EHF systems can be characterized as an uncertain second order system. Second, an adaptive extended state observer (AESO) is utilized to estimate the states of the EHF system and total disturbances, in which the observer gains are updated online by a non-linear observer bandwidth, that is as a function of the observation errors. Moreover, with the help of disturbance estimation, a novel sliding manifold is constructed with parameters adaptively adjusted by a dynamic nonlinear bandwidth function to reduce the impact of high gain problems, especially noise-sensitivity. A continuous sliding-mode (CSM) based component is also designed to handle disturbance estimation errors. Third, the stability of the closed loop system, including the proposed controller and estimator, is mathematically proved using the Lyapunov theorem. Finally, the comparative simulation results show that the proposed method has superior robustness and temperature tracking performance.

Carbon aerogel electrode for excellent dephosphorization via flow capacitive deionization

Flow-electrode capacitive deionization (FCDI) has emerged as a new method in dephosphorization, for its high efficiency and continuous operation. Using conventional carbon-based materials for fabricating FCDI electrodes have limitations in conductivity, specific surface area, toxicity, and dispersion. In this study, a new carbon aerogel (CA) was synthesized using the resorcinol–formaldehyde resin via an electric heating furnace drying method. N2 adsorption–desorption isotherm and electrochemical impedance spectroscopy shows that the material has high specific surface area and a high conductivity. CA has a faster dephosphorization rate and lower energy consumption (1.74 kWh/kg-P) (1.20 μg·min−1·cm−2) than that of activated carbon (AC) when used in FCDI dephosphorization owing to its good conductivity and dispersibility. This study demonstrates the commercial application potential of CA as an FCDI electrode material for phosphorus recovery.

Effect the hot deformation on austenite structure of the carbon steel

Purpose. Determination influence temperature and degree of hot plastic deformation carbon steel on the development secondary recrystallization of the austenite. M ethodology. The carbon steels with a concentration of carbon by 0.55 and 0.65%, which correspond to the maximum and minimum values within the brand composition for all-rolled railway wheels, were used as material for the research. The number of other chemical elements met requirements of the documentation for railway wheels. The samples for research had the form of cylinders with a diameter of 20 and a height of 40 mm. Different degrees of plastic deformation were obtained during compression with a deformation rate of 10-3 s-1. Chamber-type electric heating furnaces were used to heat the samples to temperatures of the hot pressing. When heating samples, measures are taken to prevent oxidation and a local decrease concentration of the carbon atoms on their surfaces. After heat treatment of the samples and mechanical preparation of the surface, detection of the structure of austenite was carried out using of the etching based on a mixture of solutions hydrochloric and picric acids. The structure of the steels was investigated under a light microscope. The size of the austenite grain was determined by the methods of quantitative metallographic. Findings. The study structure of the carbon steel determined that under conditions of increasing the annealing temperature, the occurrence of structural heterogeneity of the austenite is caused by a change at mechanism of the development secondary recrystallization. Starting from 10% of hot pressing, in proportion to the degree of plastic deformation, development secondary recrystallization by the mechanism of movement of the large-angle boundaries leads to grinding of the austenite grain and the formation of a homogeneous structure. At degrees of hot deformation less than 10%, the density of dislocations is not enough to form a nucleus for the development secondary recrystallization by the mechanism of movement of the large-angle boundaries. As a result, recombination of the dislocations in grains of hot deformed austenite will occur much faster, which will lead to the separation of grains into fragments. Their size will be determined by the density of dislocations introduced during hot pressing. Disorientation angles between fragments have intermediate values between boundaries with large disorientation angles and subboundaries, which determines their low mobility. For such a structure, development of the secondary recrystallization in austenite will occur by the mechanism of grain boundary dissolution. As a result, there is significant heterogeneity structure of the austenite, which is determined by the difference in sizes between neighboring grains up to several times. Originality. Depending on the conditions of hot pressing of the carbon steel, the value of plastic deformation is determined, which separates development the secondary recrystallization of the austenite by qualitatively different mechanisms. At a low value of hot deformation, when the density of dislocations is not sufficient for the formation of a nucleus of the secondary recrystallization by the mechanism movement of the large-angle boundaries, the growth austenite grains occurs by the mechanism of dissolution of the grain boundaries. Practical value. Determining effect temperature and degree of hot plastic deformation on the mechanism of the development secondary recrystallization will allow to the optimize tenology crimping the blank of the all-rolled railway wheel.

Study on early-age thermal field of single-cell box girder concrete cured with electric heating furnaces

In the cold winter, the concrete strength of box girder under steam curing is not enough and early cracks appear because of volume expansion, poor temperature control and other reasons. The electric heating furnace can provide enough temperature for concrete curing and will not produce a lot of water vapor to make the concrete expand. The construction section of the box girder of the long-span prestressed continuous rigid frame bridge is taken as the research object. The early-age thermal field of concrete under the curing of the electric heating furnace in the cold winter is studied by the method of finite element analysis and field test comparison. The comparison shows that the initial temperature growth of box girder mainly depends on the hydration heat in cement. When the temperature reaches the peak value, it is closely linked to the external conditions. The concrete curing by electric heating furnace can achieve better curing effect in the cold winter. The research results provide a cheap and efficient curing method for concrete curing in the cold winter and a scientific basis for concrete curing by electric heating furnace.

An Empirical Model for Carbon Diffusion in Grey Iron/Stainless Steel Bimetallic Composites Incorporating Eutectic Carbides

The mechanism of carbon diffusion in the as-cast and heat-treated grey iron and 304 stainless steel bimetallic composites was investigated in this study. A simplistic empirical model for the interface carbon diffusion was proposed and has been validated against the experimental data. A liquid-solid compound casting technique was used to fabricate the bimetallic composites. For the graphitizing annealing heat treatment, the bimetallic composite specimens were heated to 940 °C and held for 120 min and 240 min in an electric heating furnace. The proposed empirical model is based on the presence of eutectic carbides chill zone near the interface that formed during solidification of the liquid grey iron above the solid stainless steel substrate. It was found that the calculated carbon concentration profiles based on the proposed diffusion model were in good agreement with the experimental results.

Austenite grain growth kinetics and mechanism of grain growth in 12Cr ultra-super-critical rotor steel

ABSTRACT In this paper, the austenite grain growth behaviour of 12Cr ultra-super-critical (USC) rotor steel was investigated by a series of heat treatments. The heat treatments at heating temperatures of 900°C–1250°C and holding time of 1 h–20 h were conducted in an electric box-type heating furnace. Experimental results showed that the sizes of austenite grain were affected by heating temperatures and holding time, and heating temperature was the dominant factor. In addition, the grain growth rate changed significantly before and after the turning points of 1050°C and 1250°C. Meanwhile, an austenite grain growth mathematical model was established at different heating temperature stages, and possession of the capability to accurately predict austenite grain size was confirmed. Furthermore, the microstructure of austenite grain in the heating process was observed by optical microscope (OM) and transmission electron microscopy (TEM), which revealed the mechanism of austenite grain growth. Analysis indicated that the change of quantity of precipitate particles with increasing heating temperature was the main reason for the difference in austenite grain growth.

Field study of PAHs with their derivatives emitted from e-waste dismantling processes and their comprehensive human exposure implications

Extensive electronic waste (e-waste) recycling might be an important emission source of polycyclic aromatic hydrocarbons (PAHs) mixture, which might induce negative effects on the employees. In the present work, atmospheric pollution patterns of PAHs and their derivatives were determined in five different workshops to dismantle waste printed circuit boards (WPCBs) via thermal treatment. The results showed that mass concentrations of PAHs, chlorinated PAHs (ClPAHs), brominated PAHs (BrPAHs), oxy-PAHs (OPAHs) as well as carbazole (CBZ) were ranged from 1.53 × 104–2.02 × 105, 32.3–364, 8.29–1.13 × 103, 923–1.39 × 104 and 225–1.95 × 103 pg·m−3, respectively. Electric heating furnaces (EHF) workshops emitted relatively higher contaminants than other disposal sectors. OPAHs was found to be the most predominant derivatives of PAHs with 9,10-anthraquinone (83.0%) has the absolute superior in EHFTV, while benzo(a)anthracene-7,12-dione (>45.0%) was found to be the highest congener in other workshops, respectively. 9,10-Cl2Phe exhibited the largest contributions to the ΣClPAHs whereas the composition profiles of BrPAHs varied among five workshops. In addition to direct chlorination of parent PAHs, thermal degradation of halogenated flame retardants incorporated into plastic materials might dominate the generation of Cl/BrPAHs from e-waste dismantling activities. The specific isomeric ratios of BrPAHs (3-BrFlu/1-BrPyr and 1-BrPyr/3-BrFlu) might be used to discriminate other emission sources from pyrolysis of WPCBs. However, their specific application as novel tracers for source identification should be further verified with more studies. The emitted PAHs mixture with their derivatives in all dismantling workshops posed carcinogenic risks to these dismantling workers via inhalation, particularly the workshop using electric heating furnaces to treat router. Nevertheless, new loadings of PAHs derivatives observed from e-waste dismantling activities, as well as their comprehensive health risk assessment provides us with a fresh perspective on the source appointment and potential adverse consequences of PAHs. More attention needs to be paid to the potential carcinogenic risks of exposure to PAHs and their derivatives from e-waste dismantling processes.

Design and Research on Temperature Control System of Electric Furnace Based on PLC Touch Screen Integrated Machine

With the development of science and technology in China, temperature control system has been widely used in many fields. The emergence of PLC effectively improves the shortcomings of PID control system, optimizes the performance of PID control system, and plays a very important role in promoting industrial production and construction. In view of the design of temperature control system of heating furnace, configuration software and PLC can be used the combination of technology can achieve the goal of furnace temperature control, and it can also monitor the furnace temperature in real time and comprehensively, and then adjust the furnace temperature according to the application requirements. The investment in the process is less, which can reduce the cost to a certain extent, and also has the application advantage of high accuracy. The temperature control system of electric heating furnace is designed in this paper. PLC is mainly used, and the temperature system is controlled intelligently with touch screen. According to the actual situation and cost budget, the controller of this paper chooses Mitsubishi FX2N- 48MR series PLC. In order to achieve intelligent control, it needs to use digital PID control algorithm, which is convenient for the staff to operate Gt1040-qbbd-c series touch screen is used to realize human-computer interaction. The system can be started and stopped. The touch screen for temperature setting can be very simple to operate. The temperature change can also be visually displayed and monitored, and the whole system can be automatically set.

Integrated Reduction of the Self–Reducing Pellets on the Blast Furnace

The objective of the present work is to research a quantitate ratio of degree direct reduction inside of SRP and degree of indirect reduction outside of SRP on the top of the blast furnace.The reactions of direct and indirect reduction occurring during the heat treatment of self reducing pellets (SRP) have been studied. In this investigation Blast furnace (BF) sludge which contains particles of coke, has been included in the SRP blend as a source of solid reductant and iron bearing oxides. In the SRP as a part ot the blast furnace burden occur the reactions simultaneously: inside of SRP-direct reduction by Csolid; gasification of carbon and indirect reduction by CO; and outside of SRP-indirect reduction of iron bearing oxides by reducing gas coming from the hearth of blast furnace through the column of charged materials. The experimental setup is shown in Fig. 1. It con-sists of a electrical heating furnace, which can be moved up and down. The quartz tube passes through the furnace. The reaction zone is in the middle of the furnace. Neutral argon atmosphere is created and for indirect reduction argon changed - on hydrogen. Gases of argon, hydrogen are introduced into the furnace separately. Wire of nickel alloy chromosome joins the scales test. A thermocouple is located in the tube.The crucible of wire chrome-nickel was permeable.Metohd. The experiments was performed continuously from the start temperature (~200 ˚C) to the experimental temperature (500 ˚C; 700 ˚C; 900 ˚C; 1100 ˚C) in argon free environment. Upon reaching the desired temperature argon was replaced by hydrogen during 30 minutes. After that the reduced probe of SRP was cooled in argon. Results. The integrated degree of reduction is equal 100%, which includes 98,6 % direct reduction by solid carbon under temperatures 1100°C. The chemical analysis of the reduced SRP showed the degree of integrated reduction change from 85,79 % (900 °C) to 92,50 % (1000 °C) and 84,6% (1100°C) and metallization 83,30 % (900 °C), 89,90 % (1000 °C), 80,75 % (1100 °C).These data correspond to results of degree of reduction SRP depends on temperature

Thermodynamic feasibility for molybdenum-based gaseous oxides assisted looping coal gasification and its derived power plant

Coal utilization in chemical looping reactions is a promising approach for fuel conversion with inherent CO2 separation, but is also hindered by kinetic limitations between the solid fuel and conventional oxygen carriers. Molybdenum oxides are considered as alternative oxygen carriers in a “gaseous oxide assisted looping” strategy, which can potentially resolve the problems of slow reaction rate in fuel reactors and the difficulty of separating oxygen carriers from ash in air reactors. For the novel conception, it is necessary to specify the chemical looping process and evaluate the thermodynamic feasibility. So, a molybdenum-based gaseous oxide assisted looping coal gasification (MoCLCG) process is designed in this study. The suitable temperature conditions of individual reactors are determined by analyzing the redox reaction characteristics and physical properties of molybdenum oxides. Furthermore, to verify the systemic feasibility, the MoCLCG technology is integrated with a hybrid solid oxide fuel cell/steam turbine power plant, which obtains energy/exergy efficiencies of 39.38% (LHV) and 36.32%, respectively. The most influence factor in the system performance is the heating efficiency of electric heating furnace. An optimal mass ratio of Mo-based oxygen carrier to coal is obtained as 6.84 and exists to achieve high energy and CO2 emission reduction efficiencies, simultaneously.

Data-Driven Approach to Accommodating Multiple Simultaneous Sensor Faults in Variable-Gain PID Systems

This paper is concerned with the problem of data-driven fault-tolerant control for multiple simultaneous sensor drift faults in variable-gain digital PID systems with very large time constants and long dead time, which are exceedingly common characteristics of process control systems. No existing data-driven residual generation method can allow building (with low computational costs) residual variables independent of the state of these systems, and meanwhile guarantee that each of the sensor faults is mapped uniquely and entirely onto the associated residual variable. To solve the aforementioned technical difficulty, a novel residual generation technique is devised via the dead time as well as the coefficients and state of the variable-gain PID controller. On this basis, a methodology is developed for the purpose of the full-decoupling estimation of several sensor malfunctions from the residual variables. Finally, a resulting data-driven approach to compensate for the aforesaid faults is applied to a dual-chamber electric heating furnace (which is a typical process plant), so that the effectiveness and advantages of the proposed methods are verified by experiment.

Exploration on the Construction of Experimental System of Heating Furnace Based on Advanced Control Algorithm

This paper focuses on the advanced control algorithm in the heating furnace experimental system, and discusses the control of temperature inertia and large hysteresis. It is proposed to analyze the working principle of data acquisition and temperature control of electric heating furnace. As the object of IPC control system for data acquisition, the I/O board adopts the mechanism modeling method to identify the dichotomy method, obtains the analysis structure of the temperature object model of the electric heating circuit, and identifies the temperature control model of the electric heating circuit. The model is finally controlled by PID control, and experiments and simulations are performed using MATLAB.