scholarly journals Laboratory and Numerical Investigation of Microwave Heating Properties of Asphalt Mixture

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 146 ◽  
Author(s):  
Haopeng Wang ◽  
Yue Zhang ◽  
Yi Zhang ◽  
Shuyin Feng ◽  
Guoyang Lu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Microwave Heating ◽  
Laboratory Tests ◽  
Steel Slag ◽  
Asphalt Mixture ◽  
Electromagnetic Properties ◽  
Heating Process ◽  
Heating Efficiency ◽  
Finite Element Software ◽  
Laboratory Test Results

Microwave heating is an encouraging heating technology for the maintenance, recycling, and deicing of asphalt pavement. To investigate the microwave heating properties of asphalt mixture, laboratory tests and numerical simulations were done and compared. Two types of Stone Mastic Asphalt (SMA) mixture samples (with basalt aggregates and steel slag aggregates) were heated using a microwave oven for different times. Numerical simulation models of microwave heating of asphalt mixture were developed with finite element software COMSOL Multiphysics. The main thermal and electromagnetic properties of asphalt mixture, served as the model input parameters, were measured through a series of laboratory tests. Both laboratory-measured and numerical simulated surface temperatures were recorded and analyzed. Results show that the replacement of basalt aggregates with steel slag aggregates can significantly increase the microwave heating efficiency of asphalt mixture. Numerical simulation results have a good correlation with laboratory test results. It is feasible to use the developed model coupling electromagnetic waves with heat transfer to simulate the microwave heating process of asphalt mixture.

scholarly journals Research on microwave heating performance of modified steel slag asphalt mixture

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402199047
Author(s):  
Yanfang Song ◽  
Zhe Wang ◽  
Yan Zhou ◽  
Rong Hu
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Microwave Heating ◽  
Test Piece ◽  
Steel Slag ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Heating Process ◽  
Heating Performance ◽  
Bending Failure

Aiming at the change law of the flexural and tensile strength of the modified steel slag asphalt mixture during microwave heating, the results of this paper are as follows: the microwave heating process can achieve the recovery of the flexural and tensile properties of the modified steel slag asphalt mixture. The number of point bending failure tests continues to increase, and the recovery rate of bending and tensile properties of beams made of modified steel slag asphalt mixture will slowly decrease until the test piece is completely destroyed. The flexural and tensile strength of beams made by microwave heating asphalt mixture cannot be fully recovered, but different asphalt mixtures have different recovery effects. Compared with the ordinary basalt asphalt mixture, the steel slag asphalt mixture before modification has the same bending and tensile repair effect after microwave heating, while the modified steel slag asphalt mixture has the first bending and tensile repair effect after microwave heating increased by 23%.

scholarly journals Research on Electromagnetic Sensitivity Properties of Sodium Chloride during Microwave Heating

2020 ◽  
Vol 39 (1) ◽  
pp. 54-62
Author(s):  
Hua Chen ◽  
Junjiang Chen ◽  
Weijun Wang ◽  
Huan Lin
Keyword(s):  
Sodium Chloride ◽  
Electric Field ◽  
Water Content ◽  
Heating Rate ◽  
Microwave Heating ◽  
Resonant Cavity ◽  
Relative Dielectric Constant ◽  
Heating System ◽  
Heating Process ◽  
Heating Efficiency

AbstractThe multimode resonant cavity is the most common cavity. The material often shows on selective heating performance during the heating process due to the effect of microwave heating having a closely relationship with the electromagnetism parameters. This paper is based on finite difference time domain method (FDTD) to establish the electromagnetic-thermal model. The electromagnetic sensitivity property parameters of sodium chloride including relative dielectric constant, loss angle tangent and water content of sodium chloride is studied during the heating and drying process. The heating rate and the electric field distribution of sodium chloride, at the different water content, were simulated with the electromagnetic characteristic parameters changing. The results show that with the electromagnetic sensitivity property parameters varying, the electric field strength, heating rate and steady-state temperature of the heating material will all have a variety in the cavity. Some measures are proposed to improve the heating efficiency and ensure the stability of the microwave heating system in the industrial application.

scholarly journals Microwave Heating Characteristics of Emulsified Asphalt Repair Materials Incorporated with Steel Slag

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yongfeng Wei ◽  
Jinyang Huo ◽  
Zhenjun Wang ◽  
Jiangtao Gao
Keyword(s):  
Microwave Heating ◽  
Steel Slag ◽  
Asphalt Mixture ◽  
Maximum Temperature ◽  
Interface Area ◽  
Heating Effects ◽  
Repair Materials ◽  
Three Stages ◽  
Emulsified Asphalt ◽  
Heating Technology

Emulsified asphalt needs to be cured for a certain age after demulsification to produce strength, which seriously affects the traffic opening time. In this work, microwave heating technology was applied for emulsified asphalt repair materials. Steel slag with high microwave activity was adopted to improve the performance of emulsified asphalt repair materials by microwave heating. Effects of steel slag sizes and contents on the heating rate, temperature distribution, and thermal performance of emulsified asphalt repair materials were analyzed by close microwave heating, open microwave heating, and repair simulation tests. Results show that the temperature of emulsified asphalt repair materials presents three different heating stages under microwave irradiation. The “critical point of phase transition” in the three stages is gradually advanced with the increase in steel slag content. The core temperature and maximum temperature of emulsified asphalt repair materials with different steel slag sizes are basically the same; however, the heat distribution of emulsified asphalt repair materials is significantly different. In contrast to conventional asphalt mixture, there exists a smaller temperature difference. The temperature of repairing materials can reach above 80°C. The interface area can form an embedded interface structure. Incorporation of steel slag and adoption of microwave heating are effective to improve the performance of emulsified asphalt repair materials.

scholarly journals Simulation and Analysis of Oleic Acid Pretreatment for Microwave-Assisted Biodiesel Production

Processes ◽  
2018 ◽  
Vol 6 (9) ◽  
pp. 142 ◽  
Author(s):  
Weiquan Ma ◽  
Tao Hong ◽  
Tian Xie ◽  
Fengxia Wang ◽  
Bin Luo ◽  
...  
Keyword(s):  
Porous Media ◽  
Oleic Acid ◽  
Microwave Heating ◽  
Rapid Heating ◽  
Experimental System ◽  
Biodiesel Production ◽  
Heating Process ◽  
Acid Pretreatment ◽  
High Loss ◽  
Heating Efficiency

Oleic acid needs to be heated when it is utilized for biodiesel production, but, as a low-loss solution, oleic acid is difficult to heat by microwave. An efficient heating method for oleic acid is designed. A high loss material porous media is placed in a quartz tube, and a microwave directly heats the porous medium of the high loss material. The oleic acid flows through the pores of porous media so that the oleic acid exchanges heat during this process and rapid heating of oleic acid is achieved. A coupling model, based on the finite element method, is used to analyze the microwave heating process. The multiphysics model is based on a single mode cavity operating at 2450 MHz. An elaborate experimental system is developed to validate the multiphysics model through temperature measurements carried out for different flow velocities of oleic acid and different microwave power levels. The computational results are in good agreement with the experimental data. Based on the validated model, the effects of different sizes, porosities, and materials on microwave heating efficiency are analyzed.

Numerical Simulation of PC Steel Bar Induction Heating Process

2011 ◽  
Vol 228-229 ◽  
pp. 270-275
Author(s):  
Qian Zhe Zhao ◽  
Yi Bing Liu ◽  
Yan Ping Liu ◽  
Wei Song Zhou
Keyword(s):  
Numerical Simulation ◽  
Induction Heating ◽  
Active Power ◽  
Experimental Fact ◽  
Heating Process ◽  
Temperature Uniformity ◽  
Element Analysis ◽  
Heating Efficiency ◽  
Steel Bar ◽  
Main Factors

Based on electromagnetic and temperature field models of nonlinear ferromagnetic materials, this paper conducts a finite element analysis of the induction heating process of PC steel bar, thus obtaining the change curves of temperature, active power, heating efficiency and power density. The main factors and mechanisms affecting the heating efficiency and the temperature uniformity are analyzed systematically by a combination of the simulation result and the experimental fact. This work is expected to contribute significantly for optimizing the key parameters of induction heating production of PC steel bar.

scholarly journals Simulación y pruebas de laboratorio de un aspa de turbina de viento de 600W de acuerdo a la Norma IEC-61400-2

2019 ◽  
pp. 24-31
Author(s):  
Paulina Marin-Tellez ◽  
Víctor López-Garza ◽  
Erick Pérez-Juárez ◽  
Gilberto González-Ávalos
Keyword(s):  
Numerical Simulation ◽  
Laboratory Tests ◽  
Mechanical Tests ◽  
Normal Operation ◽  
Testing Laboratory ◽  
Finite Element Software ◽  
Standard Normal ◽  
Static Mechanical ◽  
Useful Life ◽  
Maximum Thrust

In the present work is shown the numerical simulation performed by means of finite element software (FEA) and the static mechanical tests using extensometric techniques for a wind turbine blade of 600W in accordance with the international standard IEC 61400-2. A NACA 4412 profile was used and the loads applied were selected according to the following load hypotheses described in the standard: normal operation, maximum thrust, immobilization with wind load and maximum exposure. A methodology was developed for both the simulation and for the laboratory tests, the data of the microdeformation measured by extensometry were also analyzed and compared with those obtained by the numerical simulation. Concluding that the analysis of finite elements is a key step prior to manufacturing that allows us to save resources and gives us parameters to perform both manufacturing and testing. Laboratory tests are necessary to ensure safe and reliable functioning of the blade during its useful life.

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