Experimental Analysis on the Formation of CO-NO-HC in Swirling Flow Combustion Chamber

2015 ◽  
Vol 72 (4) ◽  
Author(s):  
Mohamad Shaiful Ashrul Ishak ◽  
Mohammad Nazri Mohd. Jaafar ◽  
Wan Zaidi Wan Omar

The main purpose of this paper is to evaluate the production of CO-NO-HC emissions while varying the swirl angle of curve vane radial swirler. Swirling flow generates central recirculation region (CRZ) which is necessary for flame stability and enhances fuel air mixing. Therefore designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion inside burner system. Four radial curved vane swirlers with 30o, 40o, 50o and 60o vane angles corresponding to swirl numbers of 0.366, 0.630, 0.978 and 1.427 respectively were used in this experiment to measure the vane angles effect on emission production in the combustion chamber. Emission measurements were conducted at 5 axial distances from the burner throat, and at 5 locations along the radius starting the central axis at each section. It was found that at the core near the throat, CO and HC concentrations are low due to high available O2 and high fuel mixing rate producing efficient combustion. This is due to the high shear region created the high swirl flow.

2014 ◽  
Vol 69 (2) ◽  
Author(s):  
Mohamad Shaiful Ashrul Ishak ◽  
Mohammad Nazri Mohd Jaafar

The main purpose of this paper is to evaluate the production of CO-NO-HC emissions while varying the swirl angle of curve vane radial swirler. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and fuel air mixing enhancement. Therefore designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion inside a burner system. Four radial curve vane swirlers with 30o, 40o, 50o and 60o vane angle corresponding to swirl number of 0.366, 0.630, 0.978 and 1.427 respectively were used in this analysis to show the effect of vane angle on emission production at end of combustion chamber. Pollutant NO reduction of more than 10 percent was obtained for the swirl number of 1.427 compared to 0.366. CO emissions were reduced by 20 percent, 25 percent and 38 percent reduction in carbon monoxide (CO) emission for swirl number of 0.630, 0.978 and 1.427 compared to swirl number of 0.366 respectively. Meanwhile, there was a small decrease in unburned HC emissions when increasing the swirl number for the whole range of equivalence ratios.  Results show that the swirling action is augmented with the increase in the vane angle, which leads to better performance of CO-NO-HC emission production inside liquid fuel burner system.


2014 ◽  
Vol 69 (2) ◽  
Author(s):  
Mohamad Shaiful Ashrul Ishak ◽  
Mohammad Nazri Mohd Jaafar

The main purpose of this paper is to study the Computational Fluid Dynamics (CFD) prediction on CO-NO formation production inside the combustor close to burner throat while varying the swirl angle of the radial swirler. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and fuel air mixing enhancement. Therefore, designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion with low pressure losses. A liquid fuel burner system with different radial air swirler with 280 mm inside diameter combustor of 1000 mm length has been investigated. Analysis were carried out using four different radial air swirlers having 30°, 40°, 50° and 60° vane angles. The flow behavior was investigated numerically using CFD solver Ansys Fluent. This study has provided characteristic insight into the formation and production of CO and pollutant NO inside the combustion chamber. Results show that the swirling action is augmented with the increase in the swirl angle, which leads to increase in the center core reverse flow, therefore reducing the CO and pollutant NO formation. The outcome of this work will help in finding out the optimum swirling angle which will lead to less emission.  


2013 ◽  
Vol 712-715 ◽  
pp. 1330-1334
Author(s):  
Yin Dong Song ◽  
Yin Nan Yuan ◽  
Chun Ping Wu ◽  
Yong Wang Li ◽  
Peng Zhe Qi ◽  
...  

Three dimensional transient numerical simulation on cylinder flow field of 4B26 diesel was done by AVL FIRE. Detailed flow field structure of diesel cylinder was calculated. The typical swirl flow and squish flow were established in 4B26 diesel engine chamber. swirl flow and squish flow can increase the fuel and air mixing rate, and can improve diesel combustion and can reduce emissions of pollutants. Oil beam could accelerate the air around it.


2015 ◽  
Vol 72 (4) ◽  
Author(s):  
Mohamad Shaiful Ashrul Ishak ◽  
Mohammad Nazri Mohd. Jaafar ◽  
Wan Zaidi Wan Omar

The main purpose of this paper is to study the Computational Fluid Dynamics (CFD) prediction on temperature distribution inside the canister burner with inlet air pre-heating of 100K and 250K while varying the swirl angle of the radial swirler. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and fuel air mixing enhancement. Therefore, designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion with low pressure losses. A liquid fuel burner system with different radial air swirler with 280 mm inside diameter combustor of 1000 mm length has been investigated. Analysis were carried out using four different radial air swirlers having 30°, 40°, 50° and 60° vane angles. The flow behavior was investigated numerically using CFD solver Ansys Fluent. This study has provided characteristic insight into the distribution of temperature inside the combustion chamber. Results show that with the inlet air preheat before the combustion, the temperature distribution inside the canister would stabilize early into the chamber with higher swirl number (SN) compared without inlet air preheat. As for the inlet air preheat, the main effects are the resulting temperatures in the canister are higher, but there is a smaller hot-spot in the flame. This means that the temperature profile in the chamber is well distributed.


2014 ◽  
Vol 71 (2) ◽  
Author(s):  
Mohamad Shaiful Ashrul Ishak ◽  
Mohammad Nazri Mohd Jaafar ◽  
Wan Zaidi Wan Omar

The main purpose of this paper is to study the Computational Fluid Dynamics (CFD) prediction on the formation of carbon monoxide and oxide of nitrogen (CO-NO) inside the canister burner with inlet air pre-heating of 100 K and 250 K while varying the swirl angle of the radial swirler. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and fuel air mixing enhancement. Therefore, designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion with low pressure losses. A liquid fuel burner system with different radial air swirler with 280 mm inside diameter combustor of 1000 mm length was investigated. Analyses were carried out using four different radial air swirlers having 30°, 40°, 50° and 60° vane angles. The flow behavior was also investigated numerically using CFD solver Ansys Fluent. Overall results show that inlet air preheat quickens the completion of combustion such that the CO and NO production stabilized at a point nearer to fuel injection point, and reduced the CO and NO concentrations due to the combustion. 


1990 ◽  
Vol 112 (4) ◽  
pp. 786-791 ◽  
Author(s):  
C. Gau ◽  
W. B. Hwang

Experiments have been performed in a large circular pipe to study and obtain the film cooling effectivenesses with the presence of weak swirling flow in the mainstream. The swirling flow is generated by a flat vane swirler situated upstream. Cooling film is injected from an annular slot formed by the pipe wall and the circular cover plate. The radial temperature distribution measurements at several axial locations were used to infer the rate of mixing of film jet with swirling flow. The swirl number, which increases with turbulence intensity and swirl velocity in the mainstream, can significantly increase the mixing rate of film jet with swirl flow and decrease the film cooling effectiveness. During the course of the experiments, the blowing ratio ranged from 0.5 to 1.75 and the swirl number ranged from 0 to 0.6. Correlation equations for the film cooling effectiveness, which account for the effect of swirling flow, are obtained.


Author(s):  
Hardial Singh ◽  
◽  
Arora B.B ◽  

In the present work, the parallel hub axial flow annular diffuser's performance characteristics with divergent casing varying between equivalent cone angle (10°, 15°, and 20°) with area ratio 3 have been evaluated computationally as well as experimentally. The performance of three diffusers were tested at different inlet swirl angles (from 0° to 25°) for swirling and non-swirling flow. Simulations have been carried out on a fully developed flow at Reynolds number 2.5×105. The results were analyzed based on the velocity profiles, static pressure recovery coefficient, and the total pressure loss coefficient. The result analysis shows that the inlet swirl flow improves the recovery of pressure and also delays the flow separation on the casing. Moreover,the findings also show that the best performance was achieved in equivalent cone angle 10° at the inlet swirl angle of 7.5° compared to other diffusers.


2021 ◽  
Vol 18 (2) ◽  
pp. 47-55
Author(s):  
K.M. Moiseeva ◽  

The article is devoted to the numerical solution of the problem of the combustion of powder metal fuel in a combustion chamber with swirling flow. A physico-mathematical model of the flow of an air suspension of aluminum powder in a swirling flow in a cylindrical combustion chamber with a sudden expansion is presented. The physical and mathematical formulation of the problem is based on the approaches of the mechanics of two-phase reacting media. The solution was carried out using the arbitrary discontinuity decay method. The results of a numerical parametric study of the features of the combustion of an air suspension of aluminum powder depending on its composition, the axial flow rate of the mixture at the entrance to the combustion chamber, and the value of the swirl speed are shown.


The world’s energy demand has increased drastically in the past and is likely to increase even more in the upcoming years. The fossil fuels are non-renewable energy, depleted at fast rate and this fact intensifies the need to look for alternative fuels to meet our day to day energy needs in all power sectors. The consumption rate of energy has increased tremendously and it necessitates increased supply of energy in all forms. The conventional energy resources like diesel, petroleum, gas and coal will soon be depleted. Hence there is a dire requirement to generate alternative sources of the fuel. Biodiesel is one of the best alternative and renewable fuel. It is oxygenate, Sulphur free and biodegradable. Oxygen content in biodiesel helps to improve the efficiency of the engine. Combustion chamber in compression ignition engine is one of the most important roles to enhance the fuel – air mixing rate (swirl) in short possible time. The turbulence is guided by the shape of the combustion chamber. The air swirl is created in combustion chamber, when the fuel air mixing rate increases. Hence the time duration of air fuel mixing rate decreases. The overall duration of the combustion process to shorten as swirl has leads to increases mechanical efficiency. In this work, in which biodiesel is prepared by transesterification process and engine performance is optimized by different parameters such as Piston shape, Load and Blend ratio and analyzed by Analysis of Variance.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Shuhn-Shyurng Hou ◽  
Ching-Hung Chou

The objective of this study is to investigate the influence of three significant parameters, namely, swirl flow, loading height, and semi-confined combustion flame, on thermal efficiency andCOemissions of a swirl flow gas burner. We focus particularly on the effects of swirl angle and inclination angle on the performance of the swirl flow burner. The results showed that the swirl flow burner yields higher thermal efficiency and emits lowerCOconcentration than those of the conventional radial flow burner. A greater swirl angle results in higher thermal efficiency andCOemission. With increasing loading height, the thermal efficiency increases but theCOemission decreases. For a lower loading height (2 or 3 cm), the highest efficiency occurs at the inclination angle 15°. On the other hand, at a higher loading height, 4 cm, thermal efficiency increases with the inclination angle. Moreover, the addition of a shield can achieve a great increase in thermal efficiency, about 4-5%, and a decrease inCOemissions for the same burner (swirl flow or radial flow).


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