Experimental Study of Hot Surface Ignition of Prevaporized Jet-A and Canola Methyl Ester

2016 ◽  
Author(s):  
Alex Spens ◽  
Jesse Harter ◽  
Ramkumar N. Parthasarathy ◽  
Subramanya R. Gollahalli
Keyword(s):  
Methyl Ester ◽  
Combustion Chamber ◽  
Ignition Delay ◽  
High Speed ◽  
Power Input ◽  
Ignition Energy ◽  
Hot Surface Ignition ◽  
Ignition Characteristics ◽  
Set Up ◽  
Hot Surface

In order to understand the ignition characteristics of liquid biofels such as canola methyl ester (CME), a set-up was built and tested. The rectangular combustion chamber (7 cm by 7 cm by 33cm high) had a viewing window in the front. Liquid fuel was injected into a stream of hot air, vaporized and mixed and the fuel/air mixture was passed through the combustion chamber vertically upward. The combustion chamber was filled with mixtures of various equivalence ratios. A 120V dryer heating element was mounted horizontally at the center of the chamber and served as the hot surface. The power input to the hot surface, the temperatures at different locations inside the chamber and images obtained from a high speed camera were recorded simultaneously. The ignition delay, ignition energy and flame velocities were documented over a range of equivalence ratios with Jet-A and CME as fuels. The ignition delay and ignition energy reached minimum values around equivalence ratios of 1.1–1.3. The ignition delay and ignition energy values for CME were comparable to those of Jet A and the flame velocities were 30% lower. This set-up can be used to measure relative ignition characteristics of liquid biofuels and blends of biofuels and petroleum fuels.

Hot Surface Ignition Properties of Jet-A/Canola Methyl Ester Blends in a Constant Volume Chamber

2018 ◽  
Author(s):  
Bach Duong ◽  
Ramkumar N. Parthasarathy ◽  
Subramanya R. Gollahalli
Keyword(s):  
Methyl Ester ◽  
Combustion Chamber ◽  
Flame Front ◽  
Equivalence Ratio ◽  
Ignition Energy ◽  
Hot Surface Ignition ◽  
Surface Ignition ◽  
Constant Volume Chamber ◽  
Hot Surface ◽  
Petroleum Fuels

In recent years, biofuels have emerged as an attractive alternative to traditional petroleum fuels due to their renewable and almost carbon-neutral nature. While the fundamental ignition properties of petroleum fuels are well understood, knowledge of ignition properties of biofuels and their blends with petroleum fuels is limited. Studies of the fundamental ignition properties of biofuels are important for the safety of storage and transportation of these fuels. The objective of this study was to compare the relative hot surface ignition properties of biofuel blends at different equivalence ratios in a constant-volume chamber. Properties that were measured in this study are: ignition energy, time interval for ignition, ignition surface temperature, and flame front velocities. The fuels studied were blends of Jet A (petroleum fuel) and canola methyl ester, CME (biofuel) over an equivalence ratio range of 0.75–2.0. A commercially available silicon carbide dryer ignitor was used as the ignition source and was located in the center of the combustion chamber. A high-speed camera recorded the propagation of the flame following ignition, allowing for the calculation of the flame front velocity. K-type thermocouples measured the temperature of the mixture at selected points inside the combustion chamber. It was found that the ignition temperature of the air-fuel mixture was nearly constant for all fuels at about 630°C (903 K). The ignition energy reached a minimum value around an equivalence ratio of 1.1–1.3 for all the blends.

Combustion and Oxidation of Lube Oils at Gas Turbine Conditions: Experimental Methods

2021 ◽  
Author(s):  
Eric L. Petersen ◽  
Olivier Mathieu ◽  
James C. Thomas ◽  
Sean P. Cooper ◽  
David S. Teitge ◽  
...  
Keyword(s):  
Shock Tube ◽  
Gas Turbine ◽  
Elevated Temperatures ◽  
Hot Surface Ignition ◽  
Autoignition Temperature ◽  
Surface Ignition ◽  
Lubrication Oil ◽  
Set Up ◽  
Lower Temperature ◽  
Hot Surface

Abstract Because of the high temperatures involved, undesirable ignition events can happen during gas turbine operation, often necessitating expensive down time and repairs. The ignition events are frequently linked to the lubricant, a flammable mixture of large hydrocarbons with a very low vapor pressure. To understand better the role of the lubricant in such ignition events, increased understanding of the fundamental thermal and oxidation characteristics of such oils is needed. To this end, a suite of different tests has been set up and demonstrated at the TEES Turbomachinery Laboratory at Texas A&M University (TAMU) to study various aspects of lubrication oil breakdown and oxidation at elevated temperatures, mostly those related to their coking and ignition behaviors. Five types of tests have been implemented: ignition delay time measurements using a shock tube; hot surface ignition (HSI); autoignition temperature (AIT) determination; thermal cook-off under controlled heating; and a high-temperature coking experiment. Such tests can be used both for fundamental understanding of how lube oils burn and for comparing the reactivity of various types and grades of oil. Each technique at TAMU is briefly described in this paper as they pertain to gas turbine lube oils, and sample results are presented for a common lubrication oil, Mobil DTE 732. For this oil, the HSI tests produced a lowest temperature without ignition of 510°C, and in shock-tube measurements, lower-temperature ignition kinetics are observed below about 1300 K, even at 1 atm. Typical AIT values for oils have been found to be around 370°C but do vary amongst brands, types, and level of degradation. The measured temperatures for the exothermic and boiling events were measured as 166±2 °C and 277±4 °C using the cook-off rig.

Experimental Investigation on Combustion and Emission Characteristics of Modified Piston in an IDI Diesel Engine Fueled with Ethyl Alcohol

2014 ◽  
Vol 984-985 ◽  
pp. 873-877 ◽  
Author(s):  
M. Parthasarathy ◽  
J. Isaac Joshua Ramesh Lalvani ◽  
E. Prakash ◽  
S. Jayaraj ◽  
K. Annamalai
Keyword(s):  
Combustion Chamber ◽  
Ethyl Alcohol ◽  
Ignition Temperature ◽  
Flame Temperature ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Hot Surface Ignition ◽  
Compression Ignition Engines ◽  
Surface Ignition ◽  
Hot Surface

Compression ignition engines with ethyl alcohol as a fuel are associated with some problems. Because of ethyl alcohol has high self-ignition temperature. It can be used in compression engine by hot surface ignition method which is used to resolve the ignition of the fuel. The modification of the engine is carried out in such a way that a pre combustion chamber is designed in engine head with a provision for heat plug is made on the pre combustion chamber. A piston with squish plate is designed and thermally analyzed. The squish piston helps for attaining better homogeneous mixture than conventional piston. Thus the better combustion is obtained with the squish piston resulting with higher adiabatic flame temperature than the conventional piston. When air is inducted into the combustion chamber it is exposed to high temperature. Modifications for pure ethyl alcohol made significant improvement in thermal efficiency, torque and reduction in specific fuel consumption of an engine. The results exhibit a path toward ethyl alcohol has an effective alternative to conventional diesel engines.

scholarly journals Improvement in Ignition Delay Characteristics of Diesel Engine Combustion by Varying Combustion Chamber Air Pressure

2020 ◽  
Vol 9 (2) ◽  
pp. 1866-1870
Keyword(s):  
Diesel Engine ◽  
Surface Temperature ◽  
Combustion Chamber ◽  
Experimental Work ◽  
Ignition Delay ◽  
Injection Pressure ◽  
Air Pressure ◽  
Solid Cone ◽  
Engine Combustion ◽  
Hot Surface

Complete and clean combustion is always desirable for better performance of engine and less emissions. An experimental work is carried in constant volume combustion chamber for getting conditions like diesel engine combustion to study the ignition delay characteristics of diesel engine combustion by varying combustion chamber air pressure. In this experimental work, air pressure of combustion chamber varied from 10 to 25 bar, hot surface temperature inside the combustion chamber varied from 350°C to 550°C and fuel injection pressures varied from 100 to 200 bar for hollow cone spray and solid cone spray . For this work a set-up is made in which the flame detection is done by digital storage oscilloscope using an optical method. The findings of the work suggests that combustion chamber air pressure and injection pressure are significantly varies the values of ignition delay at a particular hot surface temperature. It is also find that on increasing the values of combustion chamber air pressure and injection pressure, ignition delay values are decreases although the variation in ignition delay is less at higher injection pressure and combustion chamber air pressure.

scholarly journals The Effects of Electric Fields on Ignition Delay of Combustible Mixtures in Hot Surface Ignition.

1998 ◽  
Vol 64 (617) ◽  
pp. 298-304
Author(s):  
Daisuke SEGAWA ◽  
Harunori NAGATA ◽  
Takeyuki KISHI ◽  
Toshikazu KADOTA ◽  
Mitsuhiro TSUE ◽  
...  
Keyword(s):  
Electric Fields ◽  
Ignition Delay ◽  
Hot Surface Ignition ◽  
Surface Ignition ◽  
Combustible Mixtures ◽  
Hot Surface

scholarly journals The Effects of DC Electric Fields on Ignition Delay of a Hydrogen-Air Mixture in Hot Surface Ignition.

1998 ◽  
Vol 64 (623) ◽  
pp. 2319-2324
Author(s):  
Daisuke SEGAWA ◽  
Harunori NAGATA ◽  
Takeyuki KISHI ◽  
Toshikazu KADOTA ◽  
Mitsuhiro TSUE ◽  
...  
Keyword(s):  
Electric Fields ◽  
Ignition Delay ◽  
Hot Surface Ignition ◽  
Surface Ignition ◽  
Hot Surface ◽  
Dc Electric Fields

scholarly journals A study on the influence of ignition energy on ignition delay time and laminar burning velocity of lean methane/air mixture in a constant volume combustion chamber

2021 ◽  
pp. 1-4
Author(s):  
Nguyen Minh Tien Nguyen
Keyword(s):  
Combustion Chamber ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Burning Velocity ◽  
Constant Volume ◽  
Laminar Burning Velocity ◽  
Ignition Energy ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber

This study presents the effect of ignition energy (Eig) on ignition delay time (tdelay) and uncertainty of laminar burning velocity (Su0) measurement of lean methane/air mixture in a constant volume combustion chamber. The mixture at an equivalence ratio of 0.6 is ignited using a pair of electrodes at the 2-mm spark gap. Eig is measured by integrating the product of voltage V(t) and current I(t) signals during a discharge period. The in-chamber pressure profiles are analyzed using the pressure-rise method to obtain tdelay and Su0. Su0 approximates 8.0 cm/s. Furthermore, the increasing Eig could shorten tdelay, leading to a faster combustion process. However, when Eig is greater than a critical value, called minimum reliable ignition energy (MRIE), the additional elevating Eig has the marginal effect on tdelay and Su0. The existence of MRIE supports to optimize the ignition systems and partly explains why extreme-high Eig>> MRIE has less contribution to engine performance.

Auto-ignition characteristics of diesel fuel in an O2–CO2 mixture

2019 ◽  
Vol 43 (1) ◽  
pp. 1-12
Author(s):  
Yongfeng Liu ◽  
Tianpeng Zhao ◽  
Zhijun Li ◽  
Fang Wang ◽  
Shengzhuo Yao ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Flame Temperature ◽  
Zone Model ◽  
Auto Ignition ◽  
Lift Off ◽  
Ignition Characteristics ◽  
Set Up

To study diesel fuel auto-ignition in an O2–CO2 mixture, a TZ (temperature zone) model is proposed. The effect of O2 and CO2 on reaction rate is considered. The relationship between temperature and ignition delay time is obtained. Different reduced mechanisms based on steady-state assumptions are applied in three temperature zones (T ≤ 800 K, 800 K < T ≤ 1100 K, T > 1100 K). The TZ model is coupled to KIVA-3V code for simulation calculations. To support the simulations, a constant-volume combustion bomb test bench is set up to visualize diesel fuel auto-ignition in air (21%O2–79%N2), a 53%O2–47%CO2 mixture, and a 61%O2–39%CO2 mixture. Ignition delay time and the flame image in these three conditions are compared and analyzed. Then the flame temperature contour and the flame lift-off length in a 53%O2–47%CO2 mixture and a 61%O2–39%CO2 mixture are analyzed. The results show that diesel fuel auto-ignition can be achieved in the tested O2–CO2 mixture. The TZ model can predict the auto-ignition characteristics of diesel fuel in a 53%O2–47%CO2 mixture and a 61%O2–39%CO2, with errors of 12% and 10%, respectively. In these two conditions, the ignition delay time and flame lift-off length are shorter than they are in air.

Study on Electrical Ignition Characteristics of HAN-Based Liquid Propellant Spray

2012 ◽  
Vol 588-589 ◽  
pp. 268-272
Author(s):  
Yong Gang Yu ◽  
Chun Yi Lu ◽  
Na Zhao ◽  
Xin Lu
Keyword(s):  
High Speed ◽  
Ignition Delay Time ◽  
Pulse Discharge ◽  
Digital Camera ◽  
Liquid Propellant ◽  
Camera System ◽  
Droplet Cluster ◽  
The Mean ◽  
Ignition Characteristics ◽  
Set Up

In order to study the electrical ignition method of liquid propellant spray, two experimental devices of liquid propellant spray and alternating current (AC) pulse discharge were designed. By using of high speed digital camera system, the test on electrical ignition of HAN-based liquid propellant LP1846 spray were carried out under different injection pressures. The results show that under 50W AC pulse discharge conditions, LP1846 droplet cluster, with the mean diameter in the range of 20~40μm, can be ignited reliably. Based on above experiments, a simplified model of ignition delay time of LP1846 single droplet was set up, the calculation value is well matched with the experimental data.

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