Temperature Effects on Fuel Thermal Stability

1992 ◽  
Vol 114 (2) ◽  
pp. 353-358 ◽  
Author(s):  
J. S. Chin ◽  
A. H. Lefebvre ◽  
F. T.-Y. Sun
Keyword(s):  
Thermal Stability ◽  
Wall Temperature ◽  
Tube Wall ◽  
Fuel Temperature ◽  
Deposition Rates ◽  
Heated Tube ◽  
Increase With Increase ◽  
Before And After ◽  
Tube Wall Temperature ◽  
The Impact

The thermal stability characteristics of four kerosine-type fuels are examined using a heated-tube apparatus that allows independent control of fuel pressure, fuel temperature, tube-wall temperature, and fuel flow rate. It is a closed loop system, and fuel flows through the heated tube for periods ranging from 6 to 22 h. The deposition rates of carbon on the tube walls are measured by weighing the tube before and after each test. The results obtained show that tube-wall and fuel temperatures both have a marked influence on deposition rates, the impact of fuel temperature being stronger than that of wall temperature. It is also found that deposition rates increase continuously with increases in tube-wall temperature. This finding contradicts the results of previous studies, which had led to the conclusion that deposition rates increase with increase in wall temperature up to a certain value, beyond which any further increase in wall temperature causes the deposition rate to decline.

scholarly journals Temperature Effects on Fuel Thermal Stability

1991 ◽  
Author(s):  
J. S. Chin ◽  
A. H. Lefebvre ◽  
F. T.-Y. Sun
Keyword(s):  
Thermal Stability ◽  
Wall Temperature ◽  
Tube Wall ◽  
Fuel Temperature ◽  
Deposition Rates ◽  
Heated Tube ◽  
Increase With Increase ◽  
Before And After ◽  
Tube Wall Temperature ◽  
The Impact

The thermal stability characteristics of four kerosine-type fuels are examined using a heated-tube apparatus which allows independent control of fuel pressure, fuel temperature, tube-wall temperature, and fuel flow rate. It is a closed loop system, and fuet flows through the heated tube for periods ranging from 6 to 22 hrs. The deposition rates of carbon on the tube walls are measured by weighing the tube before and after each test. The results obtained show that tube-wall and fuel temperatures both have a marked influence on deposition rates, the impact of fuel temperature being stronger than that of wall temperature. It is also found that deposition rates increase continuously with increases in tube-wall temperature. This finding contradicts the results of previous studies which had led to the conclusion that deposition rates increase with increase in wall temperature up to a certain value beyond which any further increase in wall temperature causes the deposition rate to decline.

Influence of Flow Conditions on Deposits From Heated Hydrocarbon Fuels

1993 ◽  
Vol 115 (3) ◽  
pp. 433-438 ◽  
Author(s):  
J. S. Chin ◽  
A. H. Lefebvre
Keyword(s):  
Wall Temperature ◽  
Liquid Hydrocarbon ◽  
Hydrocarbon Fuels ◽  
Test Duration ◽  
Flow Conditions ◽  
Fuel Temperature ◽  
Deposition Rates ◽  
Pass System ◽  
Heated Tube ◽  
Before And After

The thermal stability characteristics of two liquid hydrocarbon fuels are examined using a single-pass system whereby the fuel under test flows only once through a heated tube which is maintained at constant temperature throughout a test duration of six hours. Deposition rates on the tube walls are measured by weighing the tube before and after each test. The experimental data are used to derive empirical equations for predicting the effects on deposition rates of variation in fuel temperature, wall temperature, and Reynolds number. It is found that deposition rates are enhanced by increases in fuel temperature, wall temperature and flow velocity, and by reductions in tube diameter. Pressure has no effect on deposition rates provided it is high enough to prevent fuel boiling.

scholarly journals Influence of Flow Conditions on Deposits From Heated Hydrocarbon Fuels

1992 ◽  
Author(s):  
J. S. Chin ◽  
A. H. Lefebvre
Keyword(s):  
Wall Temperature ◽  
Liquid Hydrocarbon ◽  
Hydrocarbon Fuels ◽  
Test Duration ◽  
Flow Conditions ◽  
Fuel Temperature ◽  
Deposition Rates ◽  
Pass System ◽  
Heated Tube ◽  
Before And After

The thermal stability characteristics of two liquid hydrocarbon fuels are examined using a single-pass system whereby the fuel under test flows only once through a heated tube which is maintained at constant temperature throughout a test duration of six hours. Deposition rates on the tube walls are measured by weighing the tube before and after each test. The experimental data are used to derive empirical equations for predicting the effects on deposition rates of variation in fuel temperature, wall temperature, and Reynolds number. It is found that deposition rates are enhanced by increases in fuel temperature, wall temperature and flow velocity, and by reductions in tube diameter. Pressure has no effect on deposition rates provided it is high enough to prevent fuel boiling.

An Experimental Investigation of Flow Boiling Characteristics in a Single Transparent Heated Microtube

2009 ◽  
Author(s):  
Osamu Kawanami ◽  
Shih-Che Huang ◽  
Kazunari Kawakami ◽  
Itsuro Honda ◽  
Yousuke Kawashima ◽  
...  
Keyword(s):  
Heat Flux ◽  
Wall Temperature ◽  
Mass Velocity ◽  
Tube Wall ◽  
Flow Boiling ◽  
High Mass ◽  
Test Fluid ◽  
High Heat Flux ◽  
Gold Plating ◽  
Heated Tube

In the present study, flow boiling in a transparent heated microtube having a diameter of 1 mm was investigated in detail. The transparent heated tube was manufactured by the electroless gold plating method. The enclosed gas-liquid interface could be clearly recognized through the tube wall, and the inner wall temperature measurement and direct heating of the film were simultaneously conducted by using the tube. Deaerated and deionized water that was subcooled temperature of 15 K was used as a test fluid, and constant and stable mass velocities of 50, 100, and 200 kg/m2s were provided by using a twin plunger pump. Among our experimental results, a vapor bubble grew up in a direction opposite the flow at a low heat flux and low mass velocities; however, this flow pattern was not observed at a high mass velocity of 200 kg/m2s. Under the conditions of G = 50 kg/m2s and high heat flux, the liquid film surrounding an elongated bubble near the heated tube wall occasionally thickened partially. The inner wall temperature exhibited large random oscillations in this regime; however, the visual observation revealed that dry-patches did not occur. The mass velocity had a negligible effect on the boiling heat transfer except in the counter-growth bubble flow regime.

scholarly journals Fouling in a Steam Cracker Convection Section Part 1: A Hybrid CFD-1D Model to Obtain Accurate Tube Wall Temperature Profiles

2019 ◽  
Vol 41 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Pieter Verhees ◽  
Abdul Rahman Akhras ◽  
Kevin M. Van Geem ◽  
Geraldine J. Heynderickx
Keyword(s):  
Wall Temperature ◽  
Tube Wall ◽  
Temperature Profiles ◽  
Tube Wall Temperature ◽  
1D Model ◽  
Steam Cracker

A Thermal Model for Concentric-Tube Overfire Air Ports

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Larry W. Swanson ◽  
David K. Moyeda
Keyword(s):  
Heat Source ◽  
Wall Temperature ◽  
Tube Wall ◽  
Operating Conditions ◽  
Transfer Model ◽  
Radiation Boundary Condition ◽  
Temperature Distributions ◽  
Airflow Distribution ◽  
Highly Nonlinear ◽  
Tube Wall Temperature

A quasisteady multimode heat-transfer model for boiler concentric-tube overfire air ports has been developed that predicts the effect of geometry, furnace heat source and heat sink temperatures, axial injector wall conduction, and coolant flow rate on the tube wall temperature distributions. The model imposes a radiation boundary condition at the outlet tip of the ports, which acts as a heat source. The model was validated using field data and showed that both the airflow distribution in the ports and tube diameter can be used to control the maximum tube wall temperature. This helps avoid tube overheating and thermal degradation. For nominal operating conditions, highly nonlinear axial temperature distributions were observed in both tubes near the hot outlet end of the port.

Nozzle tube-wall temperature measurement by radiometric techniques.

1966 ◽  
Vol 3 (7) ◽  
pp. 1144-1146
Author(s):  
E. L. GEERY ◽  
W. R. THOMPSON ◽  
J. H. BEVERIDGE ◽  
W. J. HELM
Keyword(s):  
Temperature Measurement ◽  
Wall Temperature ◽  
Tube Wall ◽  
Tube Wall Temperature
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