Showing 5 results for Combustion Chamber
Esmaeil Valizadeh, Seyed Mojtaba Mousavi Naeenian, Mohammad Mahdi Heydari, Hamidraza Saadati,
Volume 15, Issue 9 (11-2015)
Abstract
Vortex combustion chamber is the new generation of liquid propellant engines chamber, where with the help of different arrangement of injectors, an inner combustion chamber vortex flow is created. This vortex can extremely help cooling and increasing the amount of propellant components mixing in the combustion chamber so it makes it possible to create a complete combustion in a low- capacity chamber. In this research, a vortex chamber has been designed and manufactured for carrying out cold tests with water as its working fluid, in order to study impact of different parameters, including pressure drop, injector quantity and input angle, chamber diameter and the thickness of the supporting step, on the performance of this type of chambers. The designed chamber, has a great deal of capabilities such as replacement ease, change in pressure drop and injectors’ input angle and studying different supporting step’s thickness to create vortex flow. Since practical investigation of all parameters is not cost-effective, cold test has been conducted for some samples and both simulation and validation have been done for it. The simulation results and chamber performance in the tests could match very well; therefore as a result of simulation assurance, the processes and other parameters in the chamber could be studied. By doing these tests we can move toward design, manufacture and test of the main vortex combustion chamber.
M. Zhaleh Rafati, A. Javadi , M. Taherinezhad, S.f. Chini,
Volume 19, Issue 2 (2-2019)
Abstract
Controlling the gas turbine emissions has led the manufacturers to use new technologies. Nitrogen oxides (NOx) are one of the major pollutants of gas turbines with natural gas as fuel. Thermal NOx is the main cause of NOx formation in gas turbines at high temperatures. So, water injection can be useful in reducing the NOx emission. In addition to NOx reduction, water injection causes an increase in carbon monoxide emission and damage to combustion chamber. Therefore, it is desirable to find the optimum amount of water injected to the combustion chamber to meet the regulations. To find the optimal water mass flow rate, we numerically investigated the combustion inside the chamber for full load and part load before and after water injection. Then, the effect of water injection at different flow rates was studied to obtain optimal water flow rate. The results showed that for the full load, the optimal water flow rate was 100% of the fuel flow rate and the upstream pressure of the feed water system was 24.45 bar. For the part load (fuel flow rate equals to 75% of the full load), the optimum water injection rate is 80% of the fuel flow rate. In this case, the pressure required for water injection is about 16.5 bar. Results also show that the change in water temperature in the range of 10-80˚C has no significant effect on NOx formation and water can be injected at the ambient temperature.
M. Nozari, S. Tabejamaat, M. Aghayari, H. Sadeghzade,
Volume 20, Issue 7 (6-2020)
Abstract
Combustion chamber has a crucial role in gas turbines and has a significant effect on the pollution and efficiency of them. Due to the complicated flow in combustion chambers because of high turbulence intensity, flow mixing, and flame behavior, prediction of the performance of such chambers is very complicated. There is a vital need for experimental investigations to study and understand the flame behavior in combustors. This experimental study was performed using a can type combustion chamber and LPG fuel at atmospheric conditions. First, stability curve, temperature distribution in the combustion chamber, and its exit plane in 6 flow conditions and then flow behavior were evaluated. The pollution at the outlet was obtained in different conditions and equivalence ratios. The results show that the flame tends to go downstream of the combustion chamber when the fuel mass flow rate increases (or in other words, by increasing the equivalence ratio) in constant air mass flow rate and finally exits from the chamber. By increasing the air mass flow rate in constant fuel mass flow rate, CO pollution is increased, and NOx pollution is decreased.
Majid Aghayari, Sadegh Tabejamaat,
Volume 22, Issue 7 (7-2022)
Abstract
In the design of the combustion chamber, various parameters should be considered. These parameters include uniform temperature distribution at the outlet of the chamber, more flame stability, lower pollution, higher combustion efficiency, lower wall temperature, and lower pressure drop in the chamber. Regarding to the complex condition of the flow in the combustion chamber due to the various effects of turbulence and mixing of flows as well as the behavior of turbulent flames, predicting the performance of flow in the combustion chambers is very complicated. In this paper, it is tried to study and optimize the combustion chamber of Amirkabir University of Technology in terms of swirler. It is done by using the numerical method and finally the selected swirler in the numerical method is tested in the experimental setup to investigate optimization method .According to the studies, swirler with an angle of 60 degrees, 12 blades, and a thickness of 0.75 mm is selected as the final case. In the experimental results, the amount of CO pollution has significantly reduced. The output temperature, the pattern factor and unburned hydrocarbon have reduced in the final case. However, the temperature uniformity inside the chamber has increased.
Aref Sohrabi, Seyyed Mahdi Mirsajedi,
Volume 24, Issue 12 (11-2024)
Abstract
This study investigates the combustion of hydrogen-methane mixtures in the annular combustion chamber of a C30 microturbine. The primary objective is to evaluate the impact of premixed methane-hydrogen combustion on pollutant emissions and outlet temperature in an annular combustion chamber. Simulations were performed using a partially premixed combustion model and the k-ε turbulence model, employing the Probability Density Function (PDF) approach for chemical reaction modeling. To ensure a detailed analysis of pollutant emissions, comparisons were conducted at a constant turbine inlet temperature. The results indicate that adding hydrogen to methane increases NOx emissions due to the higher flame temperature compared to pure methane, even at constant turbine inlet temperatures. However, this blend can reduce fuel consumption by up to 35%. Additionally, a fuel mixture of 60% methane and 40% hydrogen results in a 61% reduction in CO2 emissions. The study further revealed that, owing to the premixed nature of the fuel-air mixture, the annular geometry, and the swirling flow pattern within the combustion chamber, a fuel blend containing 30% hydrogen can lower NOx emissions to 16.1 ppm—significantly less than the 46 ppm reported in previous studies. Moreover, increasing the hydrogen fraction in the fuel reduced CO emissions by 16%. These findings demonstrate that annular combustion chambers with premixed flows and hydrogen-methane fuel blends have considerable potential for reducing pollutant emissions and optimizing fuel consumption
