High-Resolution Thermal Profiling of a Combustor in a Non-Dedicated Test Using Thermal History Coatings

2021 ◽  
Author(s):  
David Peral ◽  
Ahmed Zaid ◽  
Christoph Benninghoven ◽  
Silvia Araguas-Rodríguez ◽  
David Kluß ◽  
...  
Keyword(s):  
High Resolution ◽  
Temperature Profile ◽  
Gas Turbine ◽  
Thermal History ◽  
Cooling System ◽  
Maximum Temperature ◽  
Thermal Testing ◽  
Cooling Hole ◽  
Advanced Analysis ◽  
The Impact

Abstract The requirement for reduced emissions and the growing demand on gas turbine efficiency are in part met through increasing firing temperatures. However, development budgets leave only limited time for dedicated thermal testing. Consequently, manufacturers are seeking novel temperature measurement technologies to validate new engine designs. This paper will demonstrate how a new temperature mapping technology can be utilized for non-dedicated (multi-cycling) testing while still delivering high-resolution temperature data in a non-dedicated test on a combustor of an industrial gas turbine. Typically, thermocouples are used to monitor the temperature during tests, but they only provide one data point. Colour changing thermal paints are used to deliver measurements over complete surfaces, but they require dedicated testing with short-duration exposure, necessitating dismantling and re-assembling the engine for further testing. Thermal History Coatings (THC) present an alternative solution to providing high-density temperature information. This coating permanently changes consistent with the maximum temperature of exposure during test. A laser-based instrumentation technique is then used to obtain temperatures. The maximum temperature profile of the surface can be determined through a customized calibration. Given the complex cooling system of a combustor, the high temperatures and the long-time exposure, this case offers a unique possibility for the testing of the coating under real engine conditions. The coated region covered the external surface of the can. Highly significant is the number of measurement points in excess of 7,000 (2 × 2 mm resolution, which enables advanced analysis. This provides insight into the impact of local features, e.g. the region adjacent to a cooling hole. The temperature profile is compared to a CFD-CHT model and thermocouple measurements for the calibration of cooling pre-design methods.

Validation of Surface Temperature Measurements on a Combustor Liner Under Full-Load Conditions Using a Novel Thermal History Paint

2016 ◽  
Author(s):  
Robert Krewinkel ◽  
Jens Färber ◽  
Martin Lauer ◽  
Dirk Frank ◽  
Ulrich Orth ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal History ◽  
Measurement Techniques ◽  
Combustion Process ◽  
Lanthanide Ions ◽  
Maximum Temperature ◽  
Oxide Ceramic ◽  
Ambient Conditions ◽  
Hot Gas ◽  
Wide Range

The ever-increasing requirements on gas turbine efficiency, which are at least partially met by increasing firing temperatures, and the simultaneous demand for reduced emissions, necessitate much more accurate calculations of the combustion process and combustor wall temperatures. Thermocouples give locally very accurate measurements of these temperatures, but there is a practical limit to the amount of measurement points. Thermal paints are another established measurement technique, but are toxic and at the same time require dedicated, short-duration tests. Thermal History Paints (THPs) provide an innovative alternative to the aforementioned techniques, but so far only a limited number of tests has been conducted under real engine conditions. THPs are similar in their chemical and physical make-up to conventional thermographic phosphors which have been successfully used in gas turbine applications for on-line temperature detection before. A typical THP comprises of oxide ceramic pigments and a water based binder. The ceramic is synthesized to be amorphous and when heated it crystallizes, permanently changing the microstructure. The ceramic is doped with lanthanide ions to make it phosphorescent. The lanthanide ions act as atomic level sensors and as the structure of the material changes, so do the phosphorescent properties of the material. By measuring the phosphorescence the maximum temperature of exposure can be determined through calibration, enabling post operation measurements at ambient conditions. This paper describes a test in which THP was applied to an impingement-cooled front panel from a combustor of an industrial gas turbine. Since this component sees a wide range of temperatures, it is ideally suited for the testing of the measurement techniques under real engine conditions. The panel was instrumented with a thermocouple and thermal paint was applied to the cold side of the impingement plate. THP was applied to the hot-gas side of this plate for validation against the other measurement techniques and to evaluate its resilience against the reacting hot gas environment. The durability and temperature results of the three different measurement techniques are discussed. The results demonstrate the benefits of THPs as a new temperature profiling technique. It is shown that the THP exhibited greater durability compared to the conventional thermal paint. Furthermore, the new technology provided detailed measurements down to millimeters indicating local temperature variations and global variations over the complete component.

Validation of Surface Temperature Measurements on a Combustor Liner Under Full-Load Conditions Using a Novel Thermal History Paint

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Robert Krewinkel ◽  
Jens Färber ◽  
Ulrich Orth ◽  
Dirk Frank ◽  
Martin Lauer ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal History ◽  
New Technology ◽  
Measurement Techniques ◽  
Combustion Process ◽  
Lanthanide Ions ◽  
Maximum Temperature ◽  
Oxide Ceramic ◽  
Ambient Conditions ◽  
Hot Gas

The ever-increasing requirements on gas turbine efficiency and the simultaneous demand for reduced emissions, necessitate much more accurate calculations of the combustion process and combustor wall temperatures. Thermal history paints (THPs) is an innovative alternative to the established measurement techniques, but so far only a limited number of tests have been conducted under real engine conditions. A typical THP comprises oxide ceramic pigments and a water-based binder. The ceramic is synthesized to be amorphous and when heated it crystallizes, permanently changing the microstructure. The ceramic is doped with lanthanide ions to make it phosphorescent and as the structure of the material changes, so do the phosphorescent properties of the material. By measuring the phosphorescence, the maximum temperature of exposure can be determined, enabling postoperation measurements at ambient conditions. This paper describes a test in which THP was applied to an impingement-cooled front panel from a combustor of an industrial gas turbine. The panel was instrumented with a thermocouple (TC), and thermal paint was applied to the cold side of the impingement plate. The THP was applied to the hot-gas side of this plate for validation against the other measurement techniques and to evaluate its resilience against the reacting hot gas environment. The durability and temperature results of the three different measurement techniques are discussed. It is shown that the THP exhibited greater durability compared to the conventional thermal paint. Furthermore, the new technology provided detailed measurements indicating local temperature variations and global variations over the complete component.

Fuel Cell Temperature Control With a Precombustor in SOFC Gas Turbine Hybrids During Load Changes

2017 ◽  
Vol 14 (3) ◽  
Author(s):  
Valentina Zaccaria ◽  
Zachary Branum ◽  
David Tucker
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Real Time ◽  
Gas Turbine ◽  
Maximum Temperature ◽  
Inlet Temperature ◽  
System Efficiency ◽  
Temperature Deviation ◽  
Conservation Of Energy ◽  
The Impact

The use of high temperature fuel cells, such as solid oxide fuel cells (SOFCs), for power generation is considered a very efficient and clean solution for conservation of energy resources. When the SOFC is coupled with a gas turbine, the global system efficiency can go beyond 70% on natural gas lower heating value (LHV). However, durability of the ceramic material and system operability can be significantly penalized by thermal stresses due to temperature fluctuations and noneven temperature distributions. Thermal management of the cell during load following is therefore essential. The purpose of this work is to develop and test a precombustor model for real-time applications in hardware-based simulations, and to implement a control strategy to keep constant cathode inlet temperature during different operative conditions. The real-time model of the precombustor was incorporated into the existing SOFC model and tested in a hybrid system facility, where a physical gas turbine and hardware components were coupled with a cyber-physical fuel cell for flexible, accurate, and cost-reduced simulations. The control of the fuel flow to the precombustor was proven to be effective in maintaining a constant cathode inlet temperature during a step change in fuel cell load. With a 20 A load variation, the maximum temperature deviation from the nominal value was below 0.3% (3 K). Temperature gradients along the cell were maintained below 10 K/cm. An efficiency analysis was performed in order to evaluate the impact of the precombustor on the overall system efficiency.

Study on Relevant Effects Concerning Heat Transfer of a Convection Cooled Gas Turbine Blade Under Realistic Engine Temperature Conditions

2013 ◽  
Author(s):  
Y. Mick ◽  
B. Wörz ◽  
E. Findeisen ◽  
P. Jeschke ◽  
V. Caspary
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Thermal Stresses ◽  
Cooling System ◽  
Gas Turbine Blade ◽  
Temperature Conditions ◽  
The Impact ◽  
Operating Points

This paper presents a study of the temperature distribution of a convection cooled gas turbine blade under realistic operating temperature conditions using experimental and numerical methods. The analysis is performed experimentally in a linear cascade with exhaust gas from a kerosene combustor. Detailed information at different operating points is taken from the experiments for which conjugate heat transfer (CHT) simulations with ANSYS CFX are carried out. By comparing the experimental and numerical results, the required complexity of the simulations is defined. The subject of this study is a gas turbine rotor blade equipped with a state-of-the-art internal convection cooling system. The test rig enables the examination of the blade at temperatures up to 1300K. The temperature distribution of the blade is measured using thermocouples. The calculations are carried out using the SST turbulence model, the Gamma Theta transition model and the discrete transfer radiation model. The influence of hot gas properties and radiation effects are analysed at three different operating points. This paper gives a quantitative overview of the impact of the mentioned parameters on temperature level and distribution as well as thermal stresses in a convection cooled blade under realistic engine temperature conditions.

A Lumped Thermodynamic Model of Gas Turbine Blade Cooling: Prediction of First-Stage Blades Temperature and Cooling Flow Rates

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Roberta Masci ◽  
Enrico Sciubba
Keyword(s):  
Temperature Profile ◽  
Gas Turbine ◽  
Thermodynamic Model ◽  
Cooling System ◽  
Gas Temperature ◽  
Flow Rates ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Computationally Intensive ◽  
Cooling Air Flow

Turbine inlet temperatures (TIT) of 1500–2000 K have become a sort of standard for most modern advanced applications. First-stage blades are obviously the most exposed components to such hot gases, and thus they need proper cooling. In the preliminary design of the blades and their cooling system, designers must rely on simple models that can be further refined at a later stage, in order to have an approximate but valuable set of guidelines and to reach a feasible first-order configuration. In this paper, a simple lumped thermodynamic model of blade cooling is proposed. It is based on mass/energy balances and heat transfer correlations, and it predicts a one-dimensional temperature profile on the blade external surface along the chord for a given gas temperature profile, as well as the required cooling air flow rates to prevent blade material from creep. The greatest advantage of the model is that it can be easily adapted to any operating condition, process parameter, and blade geometry, which makes it well suited to the last technological trends, namely, the investigation of new cooling methods and alternative coolants instead of air. Therefore, the proposed model is expected to be a useful tool in the field of innovative gas turbine cycle analysis, replacing more computationally intensive and very time-consuming models.

Performance improvements of the recuperated gas turbine cycle using absorption inlet cooling and evaporative aftercooling

2002 ◽  
Vol 216 (4) ◽  
pp. 295-306 ◽  
Author(s):  
A. M. Bassily
Keyword(s):  
Gas Turbine ◽  
Parametric Study ◽  
Cooling System ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Temperature Ratio ◽  
Optimum Pressure ◽  
Performance Improvements ◽  
Gas Turbine Cycle ◽  
The Impact

An absorption inlet cooling system is introduced into the recuperated gas turbine cycle. The exhaust gases of the cycle are used to run the system. Five different layouts of the recuperated gas turbine cycle are presented. These include the effects of absorption inlet cooling, evaporative inlet cooling and evaporative cooling of compressor discharge (evaporative aftercooling), and the combined effect of absorption inlet cooling and evaporative aftercooling. A parametric study of the effect of pressure ratio, ambient temperature and relative humidity on the performance of all cycles is carried out. The results indicate that absorption inlet cooling could increase the efficiency of the recuperated cycle by up to 4 per cent, compared with 2.2 per cent for evaporative inlet cooling. Absorption inlet cooling with evaporative aftercooling could increase the optimum per efficiency of the recuperated cycle by up to 5 per cent and its maximum power by up to 65 per cent. Evaporative aftercooling reduces the impact of inlet cooling. Another parametric study of the effect of the turbine compressor inlet temperature ratio on the optimum pressure ratios indicated that cycles with evaporative aftercooling have higher optimum pressure ratios, which could be a function of the inlet temperature ratio and air temperature at the compressor outlet.

An Investigation of an Impingement / Pin-Fin Cooling System for Gas Turbine Combustor Applications

2012 ◽  
Author(s):  
Vivek Savarianandam ◽  
Steven J. Thorpe ◽  
Jon F. Carrotte ◽  
Marco Zedda
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Film Cooling ◽  
Cooling System ◽  
Turbulence Models ◽  
Efficient Design ◽  
Cold Side ◽  
Pin Fin ◽  
Impingement Zone ◽  
The Impact

Pin-fin cooling geometries are used extensively in gas turbine engine components, typically in combination with film-cooling and thermal barrier coatings. The cooling performance of this cold-side arrangement is an important factor in maintaining hot-section components below prescribed life-limiting temperatures. At a time when engine manufacturers are pursuing combustor designs that require a reduced coolant flow, robust aerodynamic and heat transfer correlations, as well as the physical insight provided by a deeper understanding of the flow processes, are essential to efficient design. In this paper both experimental and computational findings are reported for the performance of a combustor pin-fin cooling system that employs a single row of impingement feed-holes. The geometry is representative of that employed in a double-skin combustor cooling system. The data includes spatially resolved end-wall heat transfer measurements, and hot-wire traverse data for the coolant velocity and turbulence parameters. Heat transfer measurements have been obtained for the cold-side of the hot-skin, and include the impact of a gap between the cold-skin and tips of the pin-fins. The flow conditions within the pin-fin geometry can be divided between an impingement zone immediately adjacent to the feed-holes, and a fully-developed zone further downstream. In general, the impingement zone is characterised by strongly varying flow and heat transfer behaviour up to approximately six pin-fin rows from the feed-hole centre-line, and then sensibly repeating conditions within the pin-fin array thereafter downstream. The impact of the cold-skin gap is to redistribute the coolant away from the hot-skin, leading to a reduction in the hot-skin heat transfer coefficient in the developed zone. Reynolds averaged Navier-Stokes (RANS) simulations of the flow within the experimental geometry have been conducted and compared to the experimental results. Various standard turbulence models have been considered. Based on this comparison recommendations are made regarding the most appropriate computational modeling approach.

Heat Transfer Characteristics of a Blade Trailing Edge With Pressure Side Bleed Extraction

2013 ◽  
Author(s):  
H. Saxer-Felici ◽  
S. Naik ◽  
M. Gritsch
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Gas Turbine ◽  
Cooling System ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Transfer Coefficients ◽  
Trailing Edge ◽  
Heat Transfer Coefficients ◽  
The Impact

This paper investigates the heat transfer and pressure loss characteristic in the internal cooling system of the trailing edge of a gas turbine blade. The geometrical profile of the blade trailing edge and the operating conditions considered are representative of that normally found in a heavy-duty gas turbine. The trailing edge geometry consists of two radial passages with inclined turbulators which are connected with a bend. The trailing edge section consists of pins rows and a flow ejection cut-out slot. The impact of a cross-over hole in the web connecting the serpentine passages is also investigated. Both numerical and experimental studies were conducted at several passage Reynolds numbers ranging from 104 to 106. Experiments were conducted in a Perspex model at atmospheric conditions. The internal heat transfer coefficients were measured via the transient liquid crystal method and the pressure drop was measured via pressure taps. The impact of blade rotation on the heat transfer and pressure drop was also assessed numerically. Comparison of the measured and predicted heat transfer coefficients and pressure drops shows a good agreement for several flow conditions. The three-dimensional flow field in the passage and in the downstream pin banks was well captured numerically, with and without coolant injection via cross-over hole.

Development of the Tier 1 Emission Reduction Control Strategy for GE-7FDL High-Power Medium-Speed Locomotive Diesel Engine

2002 ◽  
Author(s):  
Eric R. Dillen ◽  
Shawn M. Gallagher
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Control Strategy ◽  
Cooling System ◽  
Standard Test ◽  
Tier 1 ◽  
Minimal Design ◽  
Advanced Analysis ◽  
The Impact ◽  
Locomotive Diesel

This paper summarizes the technical development of the GE-7FDL series locomotive diesel engine to EPA Tier 1 emissions standards. The goal of the project was to use the existing GE-7FDL Tier 0 engine with minimal design changes and optimize for performance with respect to the Tier 1 limits. The work focused on statistically quantifying the variation seen under standard test conditions, quantifying the impact of cooling system performance, altitude, and ambient temperature on exhaust emissions and fuel consumption, and developing a robust design and control strategy to ensure optimal emissions and fuel consumption throughout the operating range and life of the locomotive. A Tier 1 prototype locomotive was used during the development to characterize the performance trends of the engine. Testing was performed over the range of altitudes required by the EPA and advanced analysis techniques were used to develop control algorithms that meet Tier 1 emissions requirements and exceed fuel consumption commitments. Extensive verification/validation testing was performed to ensure that the design goals and process capability requirements were met.

Comparison of MK-PRISM according to horizontal resolution in South Korea

2020 ◽  
Author(s):  
Maeng-Ki Kim ◽  
Jeong Sang ◽  
Ji-hyun Yun ◽  
Ji-Seon Oh
Keyword(s):  
High Resolution ◽  
Group Performance ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Data Sets ◽  
Grid Data ◽  
The Impact ◽  
Resolution Data

<p>In this study, we produced grid climate data sets of 1km×1km and 5km×5km horizontal resolutions based on MK (Modified Korean)-PRISM (Parameter-elevation Regressions on Independent Slopes Model), a statistical method that can estimate grid data of horizontal high-resolution using observational station data in Korea. To compare the MK-PRISM performance according to resolution, RMSEs of 1km resolution data and 5km resolution data were calculated and analyzed. The RMSEs of the two data sets were similar, but the results classified according to the elevation were different. The 1km high resolution estimated data was shown to better reflect the impact of the terrain for the daily mean temperature and daily maximum temperature, whereas the difference between the two data sets for daily minimum temperature was not statistically significant at each elevation. Furthermore, we also divided the temperature data into 9-classes based on the observed temperatures, and then compared the estimated performance of the two data sets according to elevation. For the low temperature group, performance of the 1 km resolution data at high elevations outperformed that of the 5 km resolution data, regardless of the season. In addition, we have verified the improved PRIDE (PRism based Dynamic downscaling Error correction) model, which can produce future high-resolution scenarios data using the results of RCM and MK-PRISM.</p>

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