scholarly journals Experimental Prediction of Lean Blowout Limits for 3kW Micro Gas Turbine Combustor fuelled with LPG

2021 ◽  
Vol 13 (1) ◽  
pp. 89-95
Author(s):  
V. KIRUBAKARAN ◽  
David BHATT
Keyword(s):  
Pressure Drop ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Total Pressure Loss ◽  
Gas Turbine Combustor ◽  
Inlet Velocity ◽  
Lean Blowout ◽  
Micro Gas Turbine ◽  
Experimental Prediction

The Lean Blowout Limit of the combustor is one of the important performance parameters for a gas turbine combustor design. This study aims to predict the total pressure loss and Lean Blowout (LBO) limits of an in-house designed swirl stabilized 3kW can-type micro gas turbine combustor. The experimental prediction of total pressure loss and LBO limits was performed on a designed combustor fuelled with Liquefied Petroleum Gas (LPG) for the combustor inlet velocity ranging from 1.70 m/s to 11 m/s. The results show that the predicted total pressure drop increases with increasing combustor inlet velocity, whereas the LBO equivalence ratio decreases gradually with an increase in combustor inlet velocity. The combustor total pressure drop was found to be negligible; being in the range of 0.002 % to 0.065 % for the measured inlet velocity conditions. These LBO limits predictions will be used to fix the operating boundary conditions of the gas turbine combustor.

Experimental Study of Combustion on a Micro Gas Turbine Combustor

2008 ◽  
Author(s):  
Feng-Shan Wang ◽  
Wen-Jun Kong ◽  
Bao-Rui Wang
Keyword(s):  
Gas Turbine ◽  
Pressure Loss ◽  
Loss Factor ◽  
Total Pressure ◽  
Combustion Efficiency ◽  
Total Pressure Loss ◽  
Test Facility ◽  
Inlet Temperature ◽  
Micro Gas Turbine ◽  
Oil Fuel

A research program is in development in China as a demonstrator of combined cooling, heating and power system (CCHP). In this program, a micro gas turbine with net electrical output around 100kW is designed and developed. The combustor is designed for natural gas operation and oil fuel operation, respectively. In this paper, a prototype can combustor for the oil fuel was studied by the experiments. In this paper, the combustor was tested using the ambient pressure combustor test facility. The sensors were equipped to measure the combustion performance; the exhaust gas was sampled and analyzed by a gas analyzer device. From the tests and experiments, combustion efficiency, pattern factor at the exit, the surface temperature profile of the outer liner wall, the total pressure loss factor of the combustion chamber with and without burning, and the pollutants emission fraction at the combustor exit were obtained. It is also found that with increasing of the inlet temperature, the combustion efficiency and the total pressure loss factor increased, while the exit pattern factor coefficient reduced. The emissions of CO and unburned hydrogen carbon (UHC) significantly reduced, but the emission of NOx significantly increased.

Experimental and numerical prediction of lean blowout limits for micro gas turbine combustor

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kirubakaran V. ◽  
David Bhatt
Keyword(s):  
Gas Turbine ◽  
Numerical Prediction ◽  
Design Stage ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Content Type ◽  
Inlet Velocity ◽  
Lean Blowout ◽  
Micro Gas Turbine ◽  
Testing Stage

Purpose The lean blowout (LBO) limit of the combustor is one of the important performance parameters for any gas turbine combustor design. This study aims to predict the LBO limits of an in-house designed swirl stabilized 3kW can-type micro gas turbine combustor. Design/methodology/approach The experimental prediction of LBO limits was performed on 3kW swirl stabilized combustor fueled with methane for the combustor inlet velocity ranging from 1.70 m/s to 6.80 m/s. The numerical prediction of LBO limits of combustor was performed on two-dimensional axisymmetric model. The blowout limits of combustor were predicted through calculated average exit gas temperature (AEGT) method and compared with experimental predictions. Findings The results show that the predicted LBO equivalence ratio decreases gradually with an increase in combustor inlet velocity. Practical implications This LBO limits predictions will use to fix the operating boundary conditions of 3kW can-type micro gas turbine combustor. This methodology will be used in design stage as well as in the testing stage of the combustor. Originality/value This is a first effort to predict the LBO limits on micro gas turbine combustor through AEGT method. The maximum uncertainty in LBO limit prediction with AEGT is 6 % in comparison with experimental results.

Film Cooling and Aerodynamic Performance on Multi-Cavity Squealer Tip of a Turbine Blade

2021 ◽  
Author(s):  
Feng Li ◽  
Zhao Liu ◽  
Zhenping Feng
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Pressure Loss ◽  
Total Pressure ◽  
Aerodynamic Performance ◽  
Total Pressure Loss ◽  
Cooling Performance ◽  
Pressure Loss Coefficient ◽  
Blade Tip ◽  
Total Pressure Loss Coefficient

Abstract The blade tip region of the shroud-less high-pressure gas turbine is exposed to an extremely operating condition with combined high temperature and high heat transfer coefficient. It is critical to design new tip structures and apply effective cooling method to protect the blade tip. Multi-cavity squealer tip has the potential to reduce the huge thermal loads and improve the aerodynamic performance of the blade tip region. In this paper, numerical simulations were performed to predict the aerothermal performance of the multi-cavity squealer tip in a heavy-duty gas turbine cascade. Different turbulence models were validated by comparing to the experimental data. It was found that results predicted by the shear-stress transport with the γ-Reθ transition model have the best precision. Then, the film cooling performance, the flow field in the tip gap and the leakage losses were presented with several different multi-cavity squealer tip structures, under various coolant to mainstream mass flow ratios (MFR) from 0.05% to 0.15%. The results show that the ribs in the multi-cavity squealer tip could change the flow structure in the tip gap for that they would block the coolant and the leakage flow. In this study, the case with one-cavity (1C) achieves the best film cooling performance under a lower MFR. However, the cases with multi-cavity (2C, 3C, 4C) show higher film cooling effectiveness under a higher MFR of 0.15%, which are 32.6%%, 34.2%% and 41.0% higher than that of the 1C case. For the aerodynamic performance, the case with single-cavity has the largest total pressure loss coefficient in all MFR studied, whereas the case with two-cavity obtains the smallest total pressure loss coefficient, which is 7.6% lower than that of the 1C case.

Probabilistic and Numerical Modelling of a Lobed Mixer at Windmilling Conditions

2013 ◽  
Author(s):  
Maxime Lecoq ◽  
Nicholas Grech ◽  
Pavlos K. Zachos ◽  
Vassilios Pachidis
Keyword(s):  
Flow Field ◽  
Response Surface ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Engine Performance ◽  
Operating Conditions ◽  
Total Pressure Loss ◽  
Operating Point ◽  
Mixing Losses

Aero-gas turbine engines with a mixed exhaust configuration offer significant benefits to the cycle efficiency relative to separate exhaust systems, such as increase in gross thrust and a reduction in fan pressure ratio required. A number of military and civil engines have a single mixed exhaust system designed to mix out the bypass and core streams. To reduce mixing losses, the two streams are designed to have similar total pressures. In design point whole engine performance solvers, a mixed exhaust is modelled using simple assumptions; momentum balance and a percentage total pressure loss. However at far off-design conditions such as windmilling and altitude relights, the bypass and core streams have very dissimilar total pressures and momentum, with the flow preferring to pass through the bypass duct, increasing drastically the bypass ratio. Mixing of highly dissimilar coaxial streams leads to complex turbulent flow fields for which the simple assumptions and models used in current performance solvers cease to be valid. The effect on simulation results is significant since the nozzle pressure affects critical aspects such as the fan operating point, and therefore the windmilling shaft speeds and air mass flow rates. This paper presents a numerical study on the performance of a lobed mixer under windmilling conditions. An analysis of the flow field is carried out at various total mixer pressure ratios, identifying the onset and nature of recirculation, the flow field characteristics, and the total pressure loss along the mixer as a function of the operating conditions. The data generated from the numerical simulations is used together with a probabilistic approach to generate a response surface in terms of the mass averaged percentage total pressure loss across the mixer, as a function of the engine operating point. This study offers an improved understanding on the complex flows that arise from mixing of highly dissimilar coaxial flows within an aero-gas turbine mixer environment. The total pressure response surface generated using this approach can be used as look-up data for the engine performance solver to include the effects of such turbulent mixing losses.

scholarly journals Gas turbine outlets: test results

2020 ◽  
Vol 4 (394) ◽  
pp. 121-128
Author(s):  
Nikolay N. Ponomarev
Keyword(s):  
Experimental Study ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Mutual Influence ◽  
Engineering Calculation ◽  
Total Pressure Loss ◽  
Flow Section ◽  
Pressure Losses ◽  
Flow Parameters

Object and purpose of research. The object of this work is gas turbine outlet consisting of axial-radial diffuser with the struts and the volute. The purpose is to create a methodology for engineering calculations, taking into account the mutual influence of the diffuser and the volute. Materials and methods. Experimental study of the flow in the models of outlets by measuring total and static pressure in characteristic sections. Calculation of integral and averaged flow parameters in measurement sections. Visualization of boundary flows. Based on the experimental results, development of regression models for the correction factors to be applied in the theoretical model, with selection of relevant factors. Main results. An experimental study of 23 variants of models with a total volume of 112 experimental points (modes) was carried out. On the basis of the experiment, methodology and program for engineering calculation of total pressure losses in the outlets were developed. It was found that the installation of guide blades and radial ribs in the diffuser in order to reduce local expansion angles with the ultimate purpose of mitigating total pressure losses actually does not lead to this result due to the because the flow in the diffuser becomes asymmetric due to its interaction with the volute. Visualization of boundary flows in the diffusers and the volutes has been performed, which makes it possible to identify the locations of separations causing increased pressure losses. Conclusion. An engineering method for calculating the total pressure loss in gas turbine outlet has been developed. The technique makes it possible, taking size restrictions into account, to select the geometry of the flow section that ensures minimum total pressure loss.

Effects of Inlet Parameters on Combustion Performance in Gas Turbine Combustor

2018 ◽  
Vol 35 (4) ◽  
pp. 339-350
Author(s):  
Yingwen Yan ◽  
Yunpeng Liu ◽  
Liang Huang ◽  
Jinghua Li
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Combustion Efficiency ◽  
Total Pressure Loss ◽  
Inlet Pressure ◽  
Inlet Temperature ◽  
Gas Turbine Combustor ◽  
Combustion Performance ◽  
Co Emission ◽  
No Emissions

Abstract The effects of different inlet parameters such as inlet temperature and pressure on combustion performance in a single-head combustor were experimentally investigated in this study. The combustion efficiency, total pressure loss, and CO and NO emissions at the outlet of a single-head rectangular combustor with different types of swirlers were separately measured. The experimental results showed that the inlet parameters had obvious effects on the combustion performance, with critical values of 600 K for the inlet temperature and 3.5 bar for the inlet pressure. The combustion efficiency noticeably increased with an increase in the inlet pressure or temperature below these values; however, when either of the inlet parameters was above the critical value, the combustion efficiency was approximately 100 %; that is, the combustion efficiency changed little with an increase in inlet temperate or pressure. When the inlet temperature or pressure increased, NO emission increased but CO emission decreased. By fitting curves to analyze the experimental data, the empirical relationships between the emissions and the inlet temperature were observed to be $CO\; \propto \;{e^{ - T}}, NO\; \propto \;{e^T}$, and those between the emissions and the inlet pressure were $CO\, \propto \,{e^{a + bP + c{P^2}}}, NO\, \propto \,{e^P}$. The total pressure loss increased with the inlet temperature.

Prediction of lean blowout performance on variation of combustor inlet area ratio for micro gas turbine combustor

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kirubakaran V. ◽  
Naren Shankar R.
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Equivalence Ratio ◽  
Area Ratio ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Content Type ◽  
Lean Blowout ◽  
Micro Gas Turbine ◽  
Primary Zone

Purpose This paper aims to predict the effect of combustor inlet area ratio (CIAR) on the lean blowout limit (LBO) of a swirl stabilized can-type micro gas turbine combustor having a thermal capacity of 3 kW. Design/methodology/approach The blowout limits of the combustor were predicted predominantly from numerical simulations by using the average exit gas temperature (AEGT) method. In this method, the blowout limit is determined from characteristics of the average exit gas temperature of the combustion products for varying equivalence. The CIAR value considered in this study ranges from 0.2 to 0.4 and combustor inlet velocities range from 1.70 to 6.80 m/s. Findings The LBO equivalence ratio decreases gradually with an increase in inlet velocity. On the other hand, the LBO equivalence ratio decreases significantly especially at low inlet velocities with a decrease in CIAR. These results were backed by experimental results for a case of CIAR equal to 0.2. Practical implications Gas turbine combustors are vulnerable to operate on lean equivalence ratios at cruise flight to avoid high thermal stresses. A flame blowout is the main issue faced in lean operations. Based on literature and studies, the combustor lean blowout performance significantly depends on the primary zone mass flow rate. By incorporating variable area snout in the combustor will alter the primary zone mass flow rates by which the combustor will experience extended lean blowout limit characteristics. Originality/value This is a first effort to predict the lean blowout performance on the variation of combustor inlet area ratio on gas turbine combustor. This would help to extend the flame stability region for the gas turbine combustor.

Three Dimensional Performance Prediction of Advanced Swirl Vanes for Gas Turbine Airblast Atomizers

1993 ◽  
Author(s):  
Gerald J. Micklow ◽  
Karthikeyan Shivaraman ◽  
H. Lee Nguyen
Keyword(s):  
Velocity Profile ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Three Dimensional ◽  
Total Pressure Loss ◽  
Pollutant Emissions ◽  
Exit Velocity ◽  
Fuel Atomization ◽  
Swirl Vane

The performance of high shear airblast fuel injectors for advanced gas turbine combustors is highly dependent on the design of the swirl vanes. The vanes may be of the straight or curved type. Curved vanes usually exhibit lower losses but straight vanes are also used due to lower cost and ease of manufacture. These type of vanes often operate under highly stalled conditions with high total pressure loss and a highly non-uniform exit velocity profile. This can produce poor fuel atomization with a non-uniform combustor fuel distribution resulting in lowered combustor efficiency and increased pollutant emissions. Constant turning curved vanes can also be easily manufactured. Properly designed vanes result in a greatly reduced total pressure loss. The exit velocity distribution is more uniform and higher in magnitude resulting in improved fuel atomization and distribution in the combustor. The present study compares standard helical flat vane performance with a low loss curved vane designed by the author for idle, takeoff and cruise conditions. The results from a three dimensional viscous numerical flow simulation show the curved swirl vane to be clearly superior to the standard flat helical swirl vane. The curved vane has a much lower total pressure loss with a more uniform exit velocity profile. This will result in improved combustor and engine performance and reduced pollutant emissions.

Numerical and Experimental Analysis of Inlet Non-Uniformity Influence on Intercooler Performance

2012 ◽  
Author(s):  
Wei Dong ◽  
Chun Mao ◽  
Jian-Jun Zhu ◽  
Yong Chen
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Flow Path ◽  
Total Pressure Loss ◽  
Design Calculation ◽  
Flow Area ◽  
Inlet Flow

The inlet flow of intercooler will be not uniform when the air flows through diffuser behind the low-pressure compressor. With the aid of the CFD technology, the flow field and pressure drop of gas turbine intercooler are analyzed. The equivalent flow area and the equivalent heat transfer methods are proposed in numerical simulations, hence the modeling problem of entire intercooler flow path is solved effectively. Three kinds of scheme of flow path are computed and the flow fields and pressure drops are given in this paper. The influence of inlet flow non-uniformity on the performance of intercooler is analyzed. The numerical computation results indicate that the CFD technology is valuable for analyzing the details of the flow field and improving the intercooler flow path design. The combination of the CFD technology and the intercooler design technique can improve the design of the flow path of gas turbine intercooler. The total pressure loss of the intercooler can be effectively reduced by improving the inlet flow non-uniformity. By comparing the experiment results and computation results of intercooler flow and heat transfer with the plate-fin heat exchanger design calculation, inlet flow non-uniformity has less influence on the heat transfer, but has more influence on the total pressure loss. When the intercooler with special flow structure and layout for marine gas turbine is designed, inlet flow non-uniformity should be fully considered and the total pressure loss should be corrected based on experiments.

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