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Guixin Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Measurements Of Gas Temperature In Microwave Plasma At Atmospheric Pressure By Molecular Emission Spectrometry
    2017 IEEE International Conference on Plasma Science (ICOPS), 2017
    Co-Authors: Lei Deng, Guixin Zhang
    Abstract:

    In this study, gas temperature measurements of argon, nitrogen, and air Microwave Plasma are achieved by the molecular emission spectrometry of the A2Σ+→X2Πr electronic system of OH radical[1,2], and the gas temperatures at different Microwave power and gas flow rate are explored, the axial temperature distributions of nitrogen and air Microwave Plasma plume are measured. The experimental results show that the Microwave Plasma core temperature is higher than 2000 K at different working conditions, even up to over 6000 K in air Microwave Plasma. At the same working condition, the three kind of Microwave Plasma gas temperature meet TAr

  • Measurements Of Gas Temperature In Microwave Plasma At Atmospheric Pressure By Molecular Emission Spectrometry
    2017 IEEE International Conference on Plasma Science (ICOPS), 2017
    Co-Authors: Lei Deng, Guixin Zhang
    Abstract:

    In this study, gas temperature measurements of argon, nitrogen, and air Microwave Plasma are achieved by the molecular emission spectrometry of the $A^{2} \sum ^{+} \rightarrow X^{2} \prod _{r}$ electronic system of OH radical[1, 2], and the gas temperatures at different Microwave power and gas flow rate are explored, the axial temperature distributions of nitrogen and air Microwave Plasma plume are measured. The experimental results show that the Microwave Plasma core temperature is higher than 2000 K at different working conditions, even up to over 6000 K in air Microwave Plasma. At the same working condition, the three kind of Microwave Plasma gas temperature meet $T_{Ar}\, \lt T_{N2}\, \lt T_{Air}$. The gas temperature increases slightly with the increase of Microwave power, decreases slightly with the decrease of gas flow overall. The gas temperature of nitrogen and air Microwave Plasma plume reduces quickly along the axial direction. In order to verify the accuracy of molecular emission spectrometry, the thermocouple is used as a comparison to measure the temperature of the DBD argon Plasma. Experiments show that the temperature measurement results of molecular emission spectrometry and thermocouple are very consistent.

  • Experimental study on the emission spectra of Microwave Plasma at atmospheric pressure
    Journal of Applied Physics, 2014
    Co-Authors: B. Zhang, Guixin Zhang, Qiang Wang, Shanshan Liao
    Abstract:

    An experimental study on Microwave Plasma at atmospheric pressure was conducted by employing optical emission spectroscopy. Based on a Microwave Plasma generation device developed for nanoparticle synthesis, we studied the influence of input Microwave power and gas flow rate on the optical emission behaviors and electron temperature of Plasma using Ar, He, and N2 as working gas, respectively. The physics behind these behaviors was discussed. The results are useful in characterizing Microwave Plasma at atmospheric pressure and can be used for improving nanoparticle synthesis system for commercial use in the future.

  • A Large-Volume Stable Atmospheric Air Microwave Plasma Based on Inductive Coupling Window—Rectangular Resonator
    IEEE Transactions on Plasma Science, 2014
    Co-Authors: Zhong Wang, Guixin Zhang
    Abstract:

    This paper introduces a novel Microwave Plasma source based on inductive coupling window-rectangular resonator. It consists of a WR430 waveguide, an inductive coupling window, a rectangular resonator, a closed cuboid quartz cavity, and a sliding short-circuit plunger. This Microwave Plasma source can produce a large-volume stable atmospheric air Microwave Plasma, and the Plasma size is at the smallest 63 mm × (40-50) mm × 30 mm. The Microwave reflectance ratio of the Microwave Plasma source exactly at higher power is roughly unrelated to the input Microwave power before the Plasma is produced. After the Plasma is generated, the reflectance ratio increases with the increase in the input Microwave power and the ratio at lower power is even smaller than that before the Plasma is produced. The gas temperature of the atmospheric air Microwave Plasma is approximately changeless with the input Microwave power. The atmospheric air Microwave Plasma cuts off the Microwave with the frequency of 2450 MHz.

  • Microwave Plasma ignition process of methane and air mixture under high pressure
    2013 Abstracts IEEE International Conference on Plasma Science (ICOPS), 2013
    Co-Authors: Q. Wang, Guixin Zhang
    Abstract:

    Summary form only given. Since the 21st century, searching for new ways and approaches to improve efficiency and to reduce exhaust gases of internal combustion engines has never been ceased. One of these innovation technologies is Microwave Plasma ignition. And this paper describes an applicable method for Microwave Plasma ignition. This method was realized in a metal closed cavity which imitates the combustion chamber in an internal combustion engine. The mixture of methane and air was successfully ignited by Microwave Plasma under 5~10 bar. The igniting process was recorded by a high-speed CCD camera and the curve of pressure was synchronously measured. These results were compared with the ignition process excited by a spark plug. The results show that the combustion ignited by Microwave Plasma is much more vigorous than by spark plug. The peak of pressure is higher in Microwave Plasma ignition. But the time characteristics of pressure curves show little difference between Microwave Plasma ignition and spark plug ignition.

Jae Goo Lee - One of the best experts on this subject based on the ideXlab platform.

  • Hydrogen and syngas production from glycerol through Microwave Plasma gasification
    International Journal of Hydrogen Energy, 2013
    Co-Authors: Sang Jun Yoon, Young Min Yun, Yong Ku Kim, Myung Won Seo, Ho Won Ra, Jae Goo Lee
    Abstract:

    Glycerol which is a byproduct of biodiesel production is considered as a potential feedstock for syngas production with the increase of biodiesel demand. In this study, the characteristics of glycerol gasification under a Microwave Plasma torch with varying oxygen and steam supply conditions were investigated. The experimental results demonstrated that the gasification efficiency and syngas heating value increased with the supplied Microwave power while the increase of oxygen and steam led to a lower gasification performance. In order to achieve high carbon conversion and cold gas efficiency in the Microwave Plasma gasification of glycerol, the O2/fuel ratio should be maintained at 0-0.4. It was revealed that the fuel droplet size and the mixing effect and retention time inside the Plasma flames are critical factors that influence the product gas yield and gasification efficiency. This study verified that syngas with a high content of H2and CO could be effectively produced from glycerol through Microwave Plasma gasification. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Y.c. Hong - One of the best experts on this subject based on the ideXlab platform.

  • Simple Microwave Plasma source at atmospheric pressure
    Journal of the Korean Physical Society, 2020
    Co-Authors: Y.c. Hong
    Abstract:

    We have developed a thermal Plasma source operating without electrodes. One electrodeless torch is the Microwave Plasma-torch, which can produce Plasmas in large quantities. We can generate Plasma at an atmospheric pressure by making use of the same magnetrons used as commercial Microwave ovens. Most of the magnetrons are operated at the frequency of 2.45 GHz; the magnetron power Microwave is about 1 kW. Electromagnetic waves from the magnetrons propagate through a shorted waveguide. Plasma was generated under a resonant condition, by an auxiliary ignition system. The Plasma is stabilized by vortex stabilization. Also, a high-power and high-efficiency Microwave Plasma-torch has been operated in air by combining two Microwave Plasma sources with 1 kW, 2.45 GHz. They are arranged in series to generate a high-power Plasma flame. The second torch adds all its power to the Plasma flame of the first torch. Basically, electromagnetic waves in the waveguide were studied by a High Frequency Structure Simulator (HFSS) code and preliminary experiments were conducted.

  • Optical and Structural Properties of ZnO Nanoparticles Synthesized by CO2 Microwave Plasma at Atmospheric Pressure
    Journal of Nanoparticles, 2014
    Co-Authors: Min Chun, Dae Hyun Choi, Jong Bae Park, Y.c. Hong
    Abstract:

    The results of carbon-doped zinc oxide nanoparticles synthesized by CO2 Microwave Plasma at atmospheric pressure are presented. The 2.45-GHz Microwave Plasma torch and feeder for injecting Zn granules are used in the synthesis of zinc oxide nanoparticles. The Zn granules (13.5 g/min) were introduced into the Microwave Plasma by CO2 (5 l/min) swirl gas. The Microwave power delivered to the CO2 Microwave Plasma was 1 kW. The synthesis of carbon-doped zinc oxide nanoparticles was carried out in accordance with CO2

  • Plasma Burner Enlarged by Coal Injection Into Microwave Plasma
    IEEE Transactions on Plasma Science, 2011
    Co-Authors: Y.c. Hong, Dong Hun Shin, Yong Uck Shin
    Abstract:

    An apparatus for generating a flame and, more particularly, a Microwave Plasma burner for obtaining a large-volume high-temperature Plasma flame are designed using a coal injection into the Microwave Plasma. The Plasma burner was mainly composed of a coal feeder and a stainless steel tube, as the exit for the Plasma flame, in series with a 2.45-GHz Microwave Plasma torch, in which a mixture of air and oxygen could immediately burn the powdered coal, with the help of a high atomic-oxygen density and the high-temperature Plasma. In order to examine the possibility of implementing Microwave Plasma burners at power plants, a feasibility test was conducted using the coal Plasma burner, with information obtained on the optical emission lines of the Plasma torch, the coal Plasma flames, the temperature profile along the axis of the flame, gas compositions at different coal-injection rates, etc.

  • Microwave Plasma torch operating at a low pressure for material processing
    Thin Solid Films, 2009
    Co-Authors: Y.c. Hong
    Abstract:

    Most operations involving the use of a Microwave Plasma torch are carried out at atmospheric pressure as an open system. A Microwave Plasma torch operated in a closed and isolated environment may provide an opportunity for the mass production of chemically active radicals for various chemical and biological processes. This study presents a Microwave Plasma torch operating at a low pressure in an isolated chamber. A Microwave torch operating at a low pressure may be economical in terms of capital costs, maintenance costs, and operational costs compared to other Plasma devices used in material processing operations. The properties of the torch Plasma at a low pressure were investigated. It is found that the Plasma profile at a low pressure is asymmetric with higher density on the incoming side of the Microwaves. This behavior of the torch inhibits high-power operation of the Microwave Plasma torch at a low pressure. However, the asymmetry of the Plasma profile disappears under a high gas flow rate. It was also found that a Microwave Plasma torch used at a low pressure can efficiently produce an abundance of chemical radicals.

  • Microwave Plasma torch operating in a chamber at a low pressure
    Applied Physics Letters, 2008
    Co-Authors: Y.c. Hong
    Abstract:

    A Microwave Plasma torch was operated in a chamber at a reduced pressure, and the properties of the torch Plasma were investigated. The argon torch Plasma at a reduced pressure of 150Torr was observed to be well diffused in the discharge tube instead of the filamentary structures at the atmospheric pressure. The typical torch Plasma density and electron temperature are measured to be ne=2×1014∕cm3 and Te=1.5eV, respectively, for argon Plasmas at 150Torr. It was also found that the Microwave Plasma torch at a low pressure may efficiently produce chemical radicals.

Sang Jun Yoon - One of the best experts on this subject based on the ideXlab platform.

  • Hydrogen and syngas production from glycerol through Microwave Plasma gasification
    International Journal of Hydrogen Energy, 2013
    Co-Authors: Sang Jun Yoon, Young Min Yun, Yong Ku Kim, Myung Won Seo, Ho Won Ra, Jae Goo Lee
    Abstract:

    Glycerol which is a byproduct of biodiesel production is considered as a potential feedstock for syngas production with the increase of biodiesel demand. In this study, the characteristics of glycerol gasification under a Microwave Plasma torch with varying oxygen and steam supply conditions were investigated. The experimental results demonstrated that the gasification efficiency and syngas heating value increased with the supplied Microwave power while the increase of oxygen and steam led to a lower gasification performance. In order to achieve high carbon conversion and cold gas efficiency in the Microwave Plasma gasification of glycerol, the O2/fuel ratio should be maintained at 0-0.4. It was revealed that the fuel droplet size and the mixing effect and retention time inside the Plasma flames are critical factors that influence the product gas yield and gasification efficiency. This study verified that syngas with a high content of H2and CO could be effectively produced from glycerol through Microwave Plasma gasification. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Zhu Shouzheng - One of the best experts on this subject based on the ideXlab platform.