scholarly journals Plasma Gas Temperature Control Performance of Metal 3D-Printed Multi-Gas Temperature-Controllable Plasma Jet

2021 ◽  
Vol 11 (24) ◽  
pp. 11686
Author(s):  
Yuma Suenaga ◽  
Toshihiro Takamatsu ◽  
Toshiki Aizawa ◽  
Shohei Moriya ◽  
Yuriko Matsumura ◽  
...  
Keyword(s):  
Temperature Control ◽  
Plasma Temperature ◽  
Plasma Jet ◽  
Control Performance ◽  
Gas Temperature ◽  
Temperature Plasma ◽  
Gas Channel ◽  
Computational Fluid Dynamics Analysis ◽  
3D Printed ◽  
Control Fluid

The aim of the study was to design and build a multi-gas temperature-controllable plasma jet that can control the gas temperature of plasmas with various gas species, and evaluated its temperature control performance. In this device, a fluid at an arbitrary controlled temperature is circulated through the plasma jet body. The gas exchanges heat with the plasma jet body to control the plasma temperature. Based on this concept, a complex-shaped plasma jet with two channels in the plasma jet body, a temperature control fluid (TCF) channel, and a gas channel was designed. The temperature control performance of nitrogen gas was evaluated using computational fluid dynamics analysis, which found that the gas temperature changed proportionally to the TCF temperature. The designed plasma jet body was fabricated using metal 3D-printer technology. Using the fabricated plasma jet body, stable plasmas of argon, oxygen, carbon dioxide, and nitrogen were generated. By varying the plasma jet body temperature from −30 °C to 90 °C, the gas temperature was successfully controlled linearly in the range of 29–85 °C for all plasma gas species. This is expected to further expand the range of applications of atmospheric low temperature plasma and to improve the plasma treatment effect.

Lowtemperature plasma generator for effective processing of materials

2021 ◽  
Vol 77 (5) ◽  
pp. 587-592
Author(s):  
M. Kh. Gadzhiev ◽  
A. S. Tyuftyaev ◽  
Yu. M. Kulikov ◽  
M. A. Sargsyan ◽  
D. I. Yusupov ◽  
...  
Keyword(s):  
Low Temperature ◽  
Flow Rate ◽  
Gas Flow ◽  
Arc Discharge ◽  
Plasma Jet ◽  
Plasma Generator ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
High Enthalpy ◽  
High Resource

Low-temperature plasma is used in metallurgy for steel alloying by nitrogen, deoxidization of magnetic alloys, obtaining of steels with particularly low carbon content, metal cleaning of nonmetallic inclusions, desulfurization and other refining processes. The wide application of those technologies is restrained by absence of reliable generators of low-temperature plasma (GLP) with sufficient resource of continuous operation. As a result of studies, a universal generator of high-enthalpy plasma jet of various working gases was created. The generator has expanding channel of the output electrode with an efficiency of ~60 % for argon working gas and ~80% for nitrogen and air. It was shown that the developed generator of low-temperature plasma ensures formation of a weakly diverging (2α = 12°) plasma jet with a diameter D = 5–12 mm, an enthalpy of 5–50 kJ/g and a mass average temperature of 5–10 kK, at a full electric power of the arc discharge of 5–50 kW and a plasma-forming gas flow rate of 1–3 g/s. Results of the study of propane additions to the plasma-forming gas effect on the state of cathodes with inserts made of pure tungsten, lanthanum tungsten, and hafnium presented. It was shown that a small propane addition (1%) to the plasma-forming gas, results in reducing effect of the insert material. Study of the GLP operation at arc current 100A with addition to the working gas nitrogen maximum possible volume of propane, which don’t disturb stability of arc showed that for the developed plasma generator at the nitrogen flow rate ~0,45 g/s, the propane flow rate was ~0,33 g/s (not more than ~73 % of the plasma-forming gas). The created high-resource GLP with changeable electrodes enables to obtain at the exit a high-enthalpy plasma flow of various gases (argon, nitrogen, air) and can be a prototype of more powerful plasmotrons of various technological application, in particular for plasma metallurgy.

Liquid dynamics in response to an impinging low-temperature plasma jet

2018 ◽  
Vol 52 (7) ◽  
pp. 075203 ◽  
Author(s):  
T R Brubaker ◽  
K Ishikawa ◽  
H Kondo ◽  
T Tsutsumi ◽  
H Hashizume ◽  
...  
Keyword(s):  
Low Temperature ◽  
Plasma Jet ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Liquid Dynamics

scholarly journals Mathematical modelling of thermal stresses within the borehole walls in terms of plasma action

2021 ◽  
Vol 15 (2) ◽  
pp. 63-69
Author(s):  
Anatolii Bulat ◽  
Valentyn Osіnnii ◽  
Andrii Dreus ◽  
Nataliia Osіnnia
Keyword(s):  
Mathematical Model ◽  
Thermal Stresses ◽  
Plasma Jet ◽  
Rock Breaking ◽  
Heating Time ◽  
Borehole Wall ◽  
Heated Layer ◽  
Rock Layer ◽  
Rock Fracturing ◽  
Temperature Plasma

Purpose is the development of a mathematical model to study and describe thermal processes within the borehole wall in terms of plasma-based rock breaking. Methods. The following has been applied: theoretical analysis in the framework of a theory of brittle thermoelasticity breaking, methods of mathematical modeling, and computational experiment. Findings. Brief information on the results of the development of advanced plasma-based technology for borehole reaming for hard mineral mining has been represented. The results of industrial tests of plasma plant of 150-200 kW·s power with plasma-generating gas in the air for hard rock breaking have been represented. The plant and plasma-based technology of borehole reaming were tested in underground conditions of Kryvbas mines while reaming a perimeter hole to drive a ventilation rise in silicate-magnetite quartzites. A mathematical model has been proposed to analyze heat and mechanical fields in the rock during the plasma-based action on the borehole walls. Numerical studies of the temperature dynamics and thermal stresses within the borehole-surrounding rock layer have been carried out. It has been demonstrated that if low-temperature plasma is used (Т = 3500-4000°С), thermal compressing stresses are induced within the thin rock layer; the stresses may exceed the boundary admissible ones. It has been identified that plasma-based effect on the borehole wall makes it possible to create the conditions for intense rock fracturing and breaking. Originality. Solution of a new problem of thermoelastic state of a borehole wall in terms of plasma action has been obtained. The proposed mathematical model has been formulated in a cylindrical coordinate system and considers convective and radiation heat exchange between a plasma jet and a borehole wall. Practical implications. The obtained results make it possible to assess the rock state depending on the plasma jet parameters. The proposed methods of calculations will help carry out research to evaluate breaking parameters (the required heating time, thickness of the heated layer, and approximate spall dimensions) and develop different methods for the breaking process control.

Synergistic antibacterial effects of treatments with low temperature plasma jet and pulsed electric fields

2014 ◽  
Vol 105 (10) ◽  
pp. 104103 ◽  
Author(s):  
Qian Zhang ◽  
Jie Zhuang ◽  
Thomas von Woedtke ◽  
Juergen F. Kolb ◽  
Jue Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Electric Fields ◽  
Pulsed Electric Fields ◽  
Plasma Jet ◽  
Low Temperature Plasma ◽  
Antibacterial Effects ◽  
Temperature Plasma

Boundary Layer Temperature Profile in Diamond CVD System Using Laser-Induced Fluorescence

1995 ◽  
Vol 416 ◽  
Author(s):  
Qingyu Wang ◽  
Jon L. Lindsay ◽  
David L. Hofeldt
Keyword(s):  
Boundary Layer ◽  
Temperature Profile ◽  
Population Distribution ◽  
Substrate Surface ◽  
Plasma Jet ◽  
Laser Induced Fluorescence ◽  
Diamond Growth ◽  
Oh Radicals ◽  
Measured Temperature ◽  
Gas Temperature

ABSTRACTThe gas temperature of a radio-frequency thermal plasma has been measured by laser-induced fluorescence along the axis of the plasma jet near the substrate surface. The temperature was determined from the rotational population distribution of OH radicals. From the measured temperature profile, the freestream temperature was found to be about 3400 K and the boundary layer thickness was determined to be about 1 mm. A numerical model including carbonhydrogen- argon kinetics was used to predict species concentrations near the surface of the substrate. The results indicate that all CHa radical concentrations increase with freestream temperature for temperatures between 2500-4000 K. Of the C1 radicals, methyl has the highest concentration in this range in our system, which is consistent with other reports that methyl is an important diamond growth species.

A Novel SOFC Thermal Management Strategy of SOFC-GT Hybrid System With Anode and Cathode Control Loops

2020 ◽  
Author(s):  
Jinwei Chen ◽  
Yuanfu Li ◽  
Huisheng Zhang ◽  
Zhenhua Lu
Keyword(s):  
Thermal Management ◽  
Temperature Control ◽  
Management System ◽  
Management Strategy ◽  
Inlet Temperature ◽  
Control Performance ◽  
Control Loop ◽  
Control Loops ◽  
Thermal Management System ◽  
Cathode Temperature

Abstract The SOFC performance and lifetime highly depend on the operation condition, especially the SOFC operation temperature. The temperature fluctuation causes thermal stress in electrodes and electrolyte ceramics. On the other hand, it also needs to maintain a sufficiently high temperature to enable the efficient transport of oxygen ions across the electrolyte. Therefore, it is necessary to design an effective SOFC temperature management system to guarantee safe and efficient operation. In this paper, a two-side temperature control method is proposed to avoid the temperature difference between anode and cathode. Therefore, the SOFC thermal management system includes two control loops. The anode inlet temperature and cathode inlet temperature are controlled by blowers adjusting the recirculated flow rate. In addition, the control performance of the proposed SOFC thermal management system is compared with one-side temperature control systems. The results show that both anode control loop and cathode control loop are essential to get a better control performance. The SOFC would operate with less efficiency with only anode temperature control. On the other hand, the safety problem would occur with only cathode temperature control. The temperature gradient would be more than the upper limit at a part load condition. Therefore, the SOFC thermal management strategy with anode and cathode temperature control loops is feasible for the SOFC-GT system.

Development and Characterization of a Portable Atmospheric-Pressure Argon Plasma Jet for Sterilization

2015 ◽  
Author(s):  
Zhi-Hua Lin ◽  
Jong-Shinn Wu ◽  
Chen-Yon Tobias Tschang ◽  
Chi-Feng Su ◽  
Tuoh Wu ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Argon Plasma ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Gas Temperature ◽  
E Coli ◽  
Bacteria Inactivation ◽  
Argon Plasma Jet ◽  
Absorption Power

In this study, we would like to develop a portable round argon atmospheric-pressure plasma jet (APPJ) which can be applied for general use of bacteria inactivation. The APPJ was characterized electrically and optically, which include measurements of absorption power, gas temperature and optical properties of plasma generated species. Measured OH* number density at 5 mm downstream was estimated to be 5.8 × 1015 cm−3 and the electron density and electron temperature were estimated to be 2.4 × 1015 cm−3 and 0.34 eV, respectively, in the discharge region. This APPJ was demonstrated to effectively inactivate E. coli within seconds of treatment, which shows its great potential in the future use of general bacteria inactivation and sterilization.

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