Numerical simulation of combustor temperature performance of a high-temperature high-speed heat-airflow simulation system

2016 ◽  
Vol 13 (5) ◽  
pp. 422-431 ◽  
Author(s):  
Chaozhi Cai ◽  
Leyao Fan ◽  
Bingsheng Wu
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
High Speed ◽  
Simulation System ◽  
Outlet Temperature ◽  
Gas Temperature ◽  
Fuel Gas ◽  
Content Type ◽  
Gas Ratio ◽  
Airflow Simulation

Purpose This paper aims to understand the outlet temperature distribution of the combustor of a high-temperature, high-speed heat-airflow simulation system. Design/methodology/approach The paper uses numerical simulation to study the temperature distribution of the combustor of a high-temperature, high-speed heat-airflow simulation system. First, the geometrical model of the combustor and the combustion model of the fuel are established. Then, the combustion of fuel in the combustor is simulated by using FLUENT under various conditions. Finally, the results are obtained. Findings The paper found three conclusions: when the actual fuel–gas ratio is equal to the theoretical fuel–gas ratio, the temperature in the combustor of the high-temperature, high-speed heat-airflow simulation system (HTSAS) can reach its highest and the distribution is the most uniform. Although increases in the total temperature of the inlet air can increase the highest temperature in the combustor of the HTSAS, the average temperature of the combustor outlet will decrease. At the same time, it will lead to an uneven temperature distribution of the combustor outlet. When the spray angle of the kerosene droplet is at 30 degrees, the outlet temperature field of the combustor is more uniform. Originality/value The paper presents a method to analyze the combustion performance of fuel and the gas temperature distribution in the combustor. The results will lay the foundation for the gas temperature control of a combustor.

Experimental investigation of wall heat transfer due to spray combustion in a high-pressure/high-temperature vessel

2021 ◽  
pp. 146808742110072
Author(s):  
Karri Keskinen ◽  
Walter Vera-Tudela ◽  
Yuri M Wright ◽  
Konstantinos Boulouchos
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
High Temperature ◽  
High Speed ◽  
Transfer Problem ◽  
Wall Heat Transfer ◽  
Gas Temperature ◽  
Reference Case ◽  
High Pressure High Temperature

Combustion chamber wall heat transfer is a major contributor to efficiency losses in diesel engines. In this context, thermal swing materials (adapting to the surrounding gas temperature) have been pinpointed as a promising mitigative solution. In this study, experiments are carried out in a high-pressure/high-temperature vessel to (a) characterise the wall heat transfer process ensuing from wall impingement of a combusting fuel spray, and (b) evaluate insulative improvements provided by a coating that promotes thermal swing. The baseline experimental condition resembles that of Spray A from the Engine Combustion Network, while additional variations are generated by modifying the ambient temperature as well as the injection pressure and duration. Wall heat transfer and wall temperature measurements are time-resolved and accompanied by concurrent high-speed imaging of natural luminosity. An investigation with an uncoated wall is carried out with several sensor locations around the stagnation point, elucidating sensor-to-sensor variability and setup symmetry. Surface heat flux follows three phases: (i) an initial peak, (ii) a slightly lower plateau dependent on the injection duration, and (iii) a slow decline. In addition to the uncoated reference case, the investigation involves a coating made of porous zirconia, an established thermal swing material. With a coated setup, the projection of surface quantities (heat flux and temperature) from the immersed measurement location requires additional numerical analysis of conjugate heat transfer. Starting from the traces measured beneath the coating, the surface quantities are obtained by solving a one-dimensional inverse heat transfer problem. The present measurements are complemented by CFD simulations supplemented with recent rough-wall models. The surface roughness of the coated specimen is indicated to have a significant impact on the wall heat flux, offsetting the expected benefit from the thermal swing material.

scholarly journals Experimental Study of the Temperature Distribution in CRTS-II Ballastless Tracks on a High-Speed Railway Bridge

2020 ◽  
Vol 10 (6) ◽  
pp. 1980 ◽  
Author(s):  
Lei Zhao ◽  
Ling-Yu Zhou ◽  
Guang-Chao Zhang ◽  
Tian-Yu Wei ◽  
Akim D. Mahunon ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
Temperature Gradient ◽  
High Speed ◽  
Railway Track ◽  
Vertical Temperature ◽  
High Speed Railway ◽  
Extreme High Temperature ◽  
Transverse Temperature ◽  
Temperature Test

To study the temperature distribution in the China Railway Track System Type II ballastless slab track on a high-speed railway (HSR) bridge, a 1:4 scaled specimen of a simply-supported concrete box girder bridge with a ballastless track was constructed in laboratory. Through a rapid, extreme high temperature test in winter and a conventional high temperature test in summer, the temperature distribution laws in the track on the HSR bridge were studied, and the vertical and transverse temperature distribution trend was suggested for the track. Firstly, the extreme high temperature test results showed that the vertical temperature and the vertical temperature difference distribution in the track on HSR bridge were all nonlinear with three stages. Secondly, the extreme high temperature test showed that the transverse temperature distribution in the track was of quadratic parabolic nonlinear form, and the transverse temperature gradient in the bottom base was significantly higher than that of the other layers of the track. Thirdly, the three-dimensional temperature distribution in the track on HSR bridge was a nonlinear, three-stage surface. Furthermore, similar regularities were also obtained in the conventional high temperature test, in which the temperature span ranges were different from those of the extreme high temperature test. In addition, the conventional high temperature test also showed that under the natural environment conditions, the internal temperature gradient in the track layers changed periodically (over a period of 24 h).

scholarly journals Numerical Analysis on Effect of Additional Gas Injection on Characteristics around Raceway in Melter Gasifier

2019 ◽  
Vol 38 (2019) ◽  
pp. 837-848
Author(s):  
Du Kaiping ◽  
Gao Xiangzhou ◽  
Sun Haibo
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Gas Injection ◽  
Coke Oven ◽  
Pure Oxygen ◽  
Small Scale ◽  
Gas Temperature ◽  
Fuel Gas ◽  
Hot Air ◽  
Flow Circulation

AbstractThe raceway plays an important role in the mass and heat transportation inside a melter gasifier. Considering that pure oxygen at room temperature instead of hot air is injected into the melter gasifier, a two-dimensional mathematical model at steady state is developed in the current work to describe the effect of the additional gas injection on the characteristics around the raceway in melter gasifier. The results show that a high-speed jet with a highest temperature above 3500 K could be found in front of tuyere. Furthermore, a small scale of gas flow circulation occurs in front of tuyere that results in a more serious thermal damage to tuyere. In order to decrease the gas temperature in the raceway to prevent the blowing-down caused by tuyere damage, the additional gas, including N2, natural gas (NG) and coke oven gas (COG) should be injected through the tuyere. Compared with N2, additional fuel gas injection gives full play to the high temperature reduction advantage of hydrogen. In addition, considering the insufficient hearth heat after injecting NG and the effective utilization of secondary resource, an appropriate amount of COG is recommended to be injected for optimizing blast system.

Study on rheological properties of aviation lubricating oil under conditions of heavy load, high speed, and high temperature

2019 ◽  
Vol 71 (4) ◽  
pp. 525-531 ◽  
Author(s):  
Zhen Li ◽  
Xiaoli Zhao ◽  
Dezhi Zheng ◽  
Tingjian Wang ◽  
Le Gu ◽  
...  
Keyword(s):  
High Temperature ◽  
Rheological Properties ◽  
Rheological Model ◽  
High Speed ◽  
Traction Force ◽  
Lubricating Oil ◽  
Rheological Parameters ◽  
Heavy Load ◽  
Content Type ◽  
Loop Control

Purpose This study aims to evaluate the rheological properties of aviation lubricating oil under conditions of heavy load, high speed and high temperature and the applicability of the classical rheological model under severe conditions. Design/methodology/approach A Chinese aviation lubricating oil was used and its traction curves were obtained using a new two-disk tribotester. Its rheological parameters were calculated based on empirical formulae. Moreover, the traction force was calculated based on the classical Eyring rheological model. Findings The traction curves are obtained with respect to contact pressure, temperature and rolling speed. The rheological parameters are significantly influenced by environmental factors, especially viscosity. The traction force calculated using the Eyring model is consistent with the experimental results. Originality/value A novel two-disk tribotester was designed using a gas bearing and speed–force closed-loop control to ensure measurement accuracy. The mechanism of rheological properties was analyzed and the applicability of the classical rheological model under severe conditions was verified. It provided an experimental and theoretical basis for expanding the application of classical rheological models under extreme conditions.

Study on Temperature Distribution of a Honeycomb Regenerator during Preheating Process

2012 ◽  
Vol 170-173 ◽  
pp. 2699-2702
Author(s):  
Zhen Min Cui
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Temperature ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Three Dimensional ◽  
Combustion Method ◽  
Outlet Temperature ◽  
High Temperature Air Combustion ◽  
Computational Fluid Dynamics Cfd

The HiTAC technology (High Temperature Air Combustion) is a reliable, industry proven combustion method. A three-dimensional numerical model is established which is for unsteady preheating process in honeycomb regenerator. The preheating period of honeycomb was simulated by means of computational fluid dynamics (CFD) software; the outlet temperature, temperature at lengthways of gas, and temperature at lengthways of honeycomb were obtained.

Two-Dimensional Spectroscopic Observation of Nonluminous Flames in a Regenerative Industrial Furnace Using Coal Gas

2004 ◽  
Vol 126 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Y. Hino ◽  
S. Sugiyama ◽  
Y. Suzukawa ◽  
I. Mori ◽  
N. Konishi ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
Emission Intensity ◽  
Premixed Flame ◽  
Band Pass Filter ◽  
Two Dimensional ◽  
Gas Temperature ◽  
Pass Filter ◽  
Soot Particles ◽  
Coal Gas

Thermal and chemical characteristics of the flames obtained from an industrial size regenerative combustion furnace have been obtained spectroscopically. The combustion characteristics of diffusion or premixed flames in the regenerative high-temperature air combustion facility have been examined using coal gas as the fuel. The fuel gas composition consisted of H2, hydrocarbon, CO, and N2. Monochromatic images of the flames have been observed in the emission mode using a CCD camera fitted with an optical band pass filter at the desired wavelength. The two-dimensional temperature distribution in the furnace has been determined using the two-line method by utilizing the Swan emission bands from within the flame. The emission intensity profiles of NO, as well as OH and CH radicals have also been observed spectroscopically. The results showed quite uniform two-dimensional temperature distribution and emission intensity of OH and CH radical species for the diffusion flame case as compared to the premixed case using high-temperature combustion air. The premixed flame case showed high local values and large fluctuations in the combustion zone for both emission intensity and temperature distribution. The temperature distribution of soot particles in the premixed flame was also determined using the two-color optical method. The results showed high local value of temperature, similar to that found for the gas temperature using signatures for C2 species at two different wavelengths. In contrast the distribution of temperature for soot particles was different. The location of the maximum soot temperature shifted to downstream positions of the flame as compared to the maximum gas temperature regions measured from the C2 species. The experimental results are discussed in conjunction with those obtained from the heat simulation analyses.

High Temperature Pulsed Corona Processing of Fuel Gas

2004 ◽  
Vol 7 (2) ◽  
Author(s):  
A. J. M. Pemen ◽  
S. A. Nair ◽  
K. Yan ◽  
E. J. M. van Heesch ◽  
K. J. Ptasinski ◽  
...  
Keyword(s):  
High Temperature ◽  
Aromatic Hydrocarbons ◽  
Biomass Gasification ◽  
Gas Temperature ◽  
Corona Discharges ◽  
Fuel Gas ◽  
Tar Removal ◽  
Pulsed Corona ◽  
Pulsed Corona Discharges

AbstractTo utilize fuel gas obtained from biomass gasification for the production of energy or chemicals, it is necessary to clean the fuel gas. Especially heavy aromatic hydrocarbons (“tars”) must be removed. This paper gives an overview of our work on tar removal from fuel gas by means of pulsed corona discharges. A setup for pulsed corona processing at fuel gas temperatures up to 850 °C will be described. Experiments were done at gas temperatures up to 400 °C. Effects of the gas temperature on the energization of a corona reactor and on tar removal will be discussed.

Investigation on oxidation behaviors of Ti-Si-N coating at high temperature

2018 ◽  
Vol 65 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Q. Wan ◽  
Y.M. Chen ◽  
H.D. Liu ◽  
B. Yang
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Structure Evolution ◽  
Temperature Oxidation ◽  
Arc Ion Plating ◽  
Content Type ◽  
X Ray ◽  
Ion Plating ◽  
Alloy Target ◽  
Cathodic Arc

Purpose Ti-Si-N coating with nanocomposite structure is a promising protective coating for cutting tools which will be subject to high temperature oxidation during service. This study aims to investigate the thermal stability of Ti-Si-N coatings and lays the foundation for its application in high speed dry cutting. Design/methodology/approach Nanocomposite Ti-Si-N coating was deposited on stainless substrate and silicon wafer (100) by Ti90Si10 alloy target by using cathodic arc ion plating. The microstructure of Ti-Si-N coating had been detected by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Findings The results suggested that the coating was TiN nanocrystals with a diameter of 6.3 nm surrounded by amorphous Si3N4. The oxidation test was conducted under 550, 650, 750, 800, 850, 900 and 950°C for 2 h. The structure evolution was observed by Scanning electron microscope (SEM), energy dispersive spectrum (EDS), XRD and XPS. The results indicated that rutile has been formed at 650°C, while Si3N4 began to oxidized at 800°C. The grain size of TiN increased from 6.3 to 13 nm as the samples oxidized from 550 to 800. Micro-crack also formed in samples oxidized over 900°C. Originality/value Ti-Si-N coating, in this study, was deposited by cathodic arc ion plating using alloy target at high-bias voltage. The oxidation temperature ranged from 500 to 950°C with TiN coating as reference.

ALX ALLOY

Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Speed ◽  
Heat Treating ◽  
Temperature Performance ◽  
Cobalt Base

Abstract ALX is a composition of nonferrous materials with a cobalt base containing chromium, tungsten and carbon. This alloy is commonly supplied in the cast-to-shape form, having an as-cast hardness of Rockwell C60-62 and requiring no further heat treatment. ALX is also supplied as cast tool bit material and is useful where conventional high-speed steels or carbides do not function effectively. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, forming, heat treating, and machining. Filing Code: Co-35. Producer or source: Allegheny Ludlum Corporation.

CYCLOPS M4

Alloy Digest ◽  
1978 ◽  
Vol 27 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Abrasion Resistance ◽  
High Speed ◽  
Heat Treating ◽  
Heavy Duty ◽  
Maximum Hardness ◽  
Temperature Performance ◽  
Sharp Edges ◽  
Normal Carbon

Abstract CYCLOPS M4 is a deep-hardening steel that was developed to utilize the excellent abrasion resistance that results from higher-than-normal carbon and vanadium contents in the molybdenum-tungsten family of high-speed steels. It is recommended for heavy-duty cutting operations and for sharp edges for fine cuts. Cyclops M4 should always be used at or near maximum hardness. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-335. Producer or source: Cyclops Corporation.

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