scholarly journals Automated Auto-Ignition Temperature Measurement with Optical Flame Detection

2006 ◽  
Vol 60 (12) ◽  
pp. 856-857
Author(s):  
Pierre Schulz ◽  
Anne Dimitrov ◽  
Béatrice Mermillon ◽  
Alexander Smitha ◽  
Franco Ferregutti ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Ignition Temperature ◽  
Auto Ignition ◽  
Flame Detection

Pressure Sensitivity of HCCI Auto-Ignition Temperature for Oxygenated Reference Fuels

2012 ◽  
Author(s):  
Ida Truedsson ◽  
Martin Tuner ◽  
Bengt Johansson ◽  
William Cannella
Keyword(s):  
Compression Ratio ◽  
Ignition Temperature ◽  
Equivalence Ratio ◽  
Engine Speed ◽  
Pressure Sensitivity ◽  
Hcci Combustion ◽  
Air Temperatures ◽  
Auto Ignition ◽  
Temperature Heat ◽  
Pressure Trace

The current research focuses on creating an HCCI fuel index suitable for comparing different fuels for HCCI operation. One way to characterize a fuel is to use the Auto-Ignition Temperature (AIT). The AIT can be extracted from the pressure trace. Another potentially interesting parameter is the amount of Low Temperature Heat Release (LTHR) that is closely connected to the ignition properties of the fuel. The purpose of this study was to map the AIT and amount of LTHR of different oxygenated reference fuels in HCCI combustion at different cylinder pressures. Blends of n-heptane, iso-octane and ethanol were tested in a CFR engine with variable compression ratio. Five different inlet air temperatures ranging from 50°C to 150°C were used to achieve different cylinder pressures and the compression ratio was changed accordingly to keep a constant combustion phasing, CA50, of 3±1° after TDC. The experiments were carried out in lean operation with a constant equivalence ratio of 0.33 and with a constant engine speed of 600 rpm. The amount of ethanol needed to suppress LTHR from different PRFs was evaluated. The AIT and the amount of LTHR for different combinations of n-heptane, iso-octane and ethanol were charted.

The effects of coal dust concentrations and particle sizes on the minimum auto-ignition temperature of a coal dust cloud

2017 ◽  
Vol 41 (7) ◽  
pp. 908-915 ◽  
Author(s):  
Mohammed Jabbar Ajrash ◽  
Jafar Zanganeh ◽  
Behdad Moghtaderi
Keyword(s):  
Ignition Temperature ◽  
Coal Dust ◽  
Dust Cloud ◽  
Particle Sizes ◽  
Auto Ignition

DME as a Potential Alternative Fuel for Gas Turbines: A Numerical Approach to Combustion and Oxidation Kinetics

2011 ◽  
Author(s):  
Pierre A. Glaude ◽  
Rene´ Fournet ◽  
Roda Bounaceur ◽  
Michel Molie`re
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Heat Input ◽  
Ignition Delay ◽  
Gas Turbines ◽  
Ignition Temperature ◽  
Alternative Fuels ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times

Many investigations are currently carried out in order to reduce CO2 emissions in power generation. Among alternative fuels to natural gas and gasoil in gas turbine applications, dimethyl ether (DME; formula: CH3-O-CH3) represents a possible candidate in the next years. This chemical compound can be produced from natural gas or coal/biomass gasification. DME is a good substitute for gasoil in diesel engine. Its Lower Heating Value is close to that of ethanol but it offers some advantages compared to alcohols in terms of stability and miscibility with hydrocarbons. While numerous studies have been devoted to the combustion of DME in diesel engines, results are scarce as far as boilers and gas turbines are concerned. Some safety aspects must be addressed before feeding a combustion device with DME because of its low flash point (as low as −83°C), its low auto-ignition temperature and large domain of explosivity in air. As far as emissions are concerned, the existing literature shows that in non premixed flames, DME produces less NOx than ethane taken as parent molecular structure, based on an equivalent heat input to the burner. During a field test performed in a gas turbine, a change-over from methane to DME led to a higher fuel nozzle temperature but to a lower exhaust gas temperature. NOx emissions decreased over the whole range of heat input studied but a dramatic increase of CO emissions was observed. This work aims to study the combustion behavior of DME in gas turbine conditions with the help of a detailed kinetic modeling. Several important combustion parameters, such as the auto-ignition temperature (AIT), ignition delay times, laminar burning velocities of premixed flames, adiabatic flame temperatures, and the formation of pollutants like CO and NOx have been investigated. These data have been compared with those calculated in the case of methane combustion. The model was built starting from a well validated mechanism taken from the literature and already used to predict the behavior of other alternative fuels. In flame conditions, DME forms formaldehyde as the major intermediate, the consumption of which leads in few steps to CO then CO2. The lower amount of CH2 radicals in comparison with methane flames seems to decrease the possibility of prompt-NO formation. This paper covers the low temperature oxidation chemistry of DME which is necessary to properly predict ignition temperatures and auto-ignition delay times that are important parameters for safety.

Pressure dependence of the auto-ignition temperature of methane/air mixtures

1999 ◽  
Vol 65 (3) ◽  
pp. 233-244 ◽  
Author(s):  
M Caron ◽  
M Goethals ◽  
G De Smedt ◽  
J Berghmans ◽  
S Vliegen ◽  
...  
Keyword(s):  
Pressure Dependence ◽  
Ignition Temperature ◽  
Auto Ignition

Numerical Investigation of Auto-Ignition Characteristics in Microstructured Catalytic Honeycomb Reactor for CH4–Air and CH4–H2–Air Mixtures

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
H. Kayed ◽  
A. Mohamed ◽  
M. Yehia ◽  
M. A. Nemitallah ◽  
M. A. Habib
Keyword(s):  
Flow Rate ◽  
Ignition Temperature ◽  
Reaction Front ◽  
Equivalence Ratio ◽  
Thermal Conditions ◽  
Flammability Limits ◽  
Transient Conditions ◽  
Auto Ignition ◽  
Transient Simulations ◽  
Ignition Characteristics

Stable ranges of auto-ignition for the microcombustion of CH4 and CH4–H2 mixtures are identified numerically in a platinum-coated microcatalytic honeycomb reactor. Steady and transient simulations under pseudo-auto-thermal conditions were performed to investigate the coupling phenomenon between combustion and heat transfer in such microburner using ANSYS 17.2 coupled with a detailed chemkin reaction mechanism. The model was validated utilizing the available data in the literature on a similar microreactor, and the results showed good agreements. A certain amount of heat is furnished from outside at constant temperature from an external electric furnace to investigate the variations of localized self-ignition temperature while changing the flow rate and mixture strength. It was found that the ignition temperature for CH4–air mixtures is not affected by the mass flow rate. However, the ignition temperature of CH4–H2 air mixtures decreases while increasing the flow rate. The effect of equivalence ratio was studied to demonstrate the variations of flammability limits of the present microreactor. The equivalence ratio required for auto-ignition of CH4–air mixtures was found to be in the range from 0.4 up to 0.85 at a flow rate of 9.5 g/s. The reaction front moved from upstream to downstream under transient conditions matching with the reported experimental behavior in the literature.

Auto-Ignition Control in Spark-Ignition Engines Using Internal Model Control Structure

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Jorge Duarte ◽  
Jesús Garcia ◽  
Javier Jiménez ◽  
Marco E. Sanjuan ◽  
Antonio Bula ◽  
...  
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Ignition Temperature ◽  
Control Strategies ◽  
Spark Ignition ◽  
Internal Model Control ◽  
Operating Conditions ◽  
Ignition Point ◽  
Single Output ◽  
Auto Ignition

This paper analyzes the feasibility of applying model predictive control strategies for mitigation of the auto-ignition phenomenon, which affects the performance of spark-ignition internal combustion engines. The first part of this paper shows the implementation and experimental validation of a two-dimensional model, based on thermodynamic equations, to simulate operating conditions in engines fueled with natural gas. Over this validated model, several control strategies are studied in order to evaluate, through simulation analysis, which of these offer the best handling capacity of the auto-ignition phenomenon. In order to achieve this goal, multivariate control strategies are implemented for a simultaneous manipulation of the fuel/air ratio, the crank angle at ignition, and the inlet pressure. The controlled variable in this research is the temperature at the ignition point. This temperature is obtained through an estimation based on pressure in the combustion chamber at that point, which is located toward the end zone of the compression stroke. If the ignition temperature of the fuel–air mixture is reached during the compression process, then auto-ignition takes place. Proposed control strategies consist of maintaining the temperature in the ignition point below the fuel–air mixture auto-ignition temperature. The results show that auto-ignition is difficult to avoid using a single input–single output (SISO) strategy. However, a multiple input–single output (MISO) approach avoids the influence of the phenomenon without a significant impact over the engine's performance. Among the developed strategies, an approach based on model predictive control and feedforward control strategy shows the best performance, measured through the integral absolute error (IAE) index. These results open the possibility of new ways for improving the control capacity of auto-ignition phenomenon in engines compared to currently available feedback control systems.

Sign in / Sign up

Export Citation Format

Share Document