Exploring the Impact of Elevated Turbine Blade Cooling Effectiveness and Turbine Material Temperatures on Gas Turbine Engine Performance and Cost

2015 ◽  
Author(s):  
Aaron R. Byerley ◽  
August J. Rolling
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Turbine Blade ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Cooling Effectiveness ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Turbine Inlet ◽  
The Impact

Since the 1950’s, the turbine inlet temperatures of gas turbine engines have been steadily increasing as engine designers have sought to increase engine thrust-to-weight and reduce fuel consumption. In turbojets and low-bypass turbofan engines, increasing the turbine inlet temperature boosts specific thrust, which in some cases can support supersonic flight without the use of an afterburner. In high-bypass gas turbine engines, increasing the turbine inlet temperature makes possible higher bypass ratios and overall pressure ratios, both of which reduce specific fuel consumption. Increased turbine inlet temperatures, without sacrificing blade life, have been made possible through advances in blade cooling effectiveness and high-temperature turbine blade materials. Investigating the impact of higher turbine inlet temperatures and the corresponding cooling air flow rates on specific thrust, specific fuel consumption, and engine development cost is the subject of this paper. A physics-based cooling effectiveness correlation is presented for linking turbine inlet temperature to cooling flow fraction. Two cases are considered: 1) a low-bypass, mixed-exhaust, non-afterburning turbofan engine intended to support supercruising at Mach 1.5 and 2) a high-bypass, unmixed-exhaust turbofan engine intended to support highly efficient, long range flight at Mach 0.8. For each of these two cases, both baseline and enhanced cooling effectiveness values as well as both baseline and elevated turbine blade material temperatures are considered. Comparing these cases will ensure that students taking courses in preliminary engine design understand why huge research investments continue to be made in turbine blade cooling and advanced, high-temperature turbine blade material development.

Comparative Thermodynamic Analysis of Gas Turbine Systems with Turbine Blade Film Cooling

2012 ◽  
Vol 505 ◽  
pp. 539-543
Author(s):  
Kyoung Hoon Kim ◽  
Kyoung Jin Kim ◽  
Chul Ho Han
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Thermodynamic Analysis ◽  
Film Cooling ◽  
Pressure Ratio ◽  
Turbine Blades ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Blade Cooling ◽  
Turbine Inlet

Since the gas turbine systems require active cooling to maintain high operating temperature while avoiding a reduction in the system operating life, turbine blade cooling is very important and essential but it may cause the performance losses in gas turbine. This paper deals with the comparative thermodynamic analysis of gas turbine system with and without regeneration by using the recently developed blade-cooling model when the turbine blades are cooled by the method of film cooling. Special attention is paid to investigating the effects of system parameters such as pressure ratio and turbine inlet temperature on the thermodynamic performance of the systems. In both systems the thermal efficiency increases with turbine inlet temperature, but its effect is less sensitive in simpler system

scholarly journals Comprehensive Review on Leading Edge Turbine Blade Cooling Technologies

2021 ◽  
Vol 39 (2) ◽  
pp. 403-416
Author(s):  
Chirag Sharma ◽  
Siddhant Kumar ◽  
Aanya Singh ◽  
Kartik R. Bhat Hire ◽  
Vedant Karnatak ◽  
...  
Keyword(s):  
Turbine Blade ◽  
Turbine Blades ◽  
Leading Edge ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Entire Surface ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Advantages And Disadvantages ◽  
Turbine Inlet

Developments in the gas turbine technology have caused widespread usage of the Turbomachines for power generation. With increase in the power demand and a drop in the availability of fuel, usage of turbines with higher efficiencies has become imperative. This is only possible with an increase in the turbine inlet temperature (TIT) of the gas. However, the higher limit of TIT is governed by the metallurgical boundary conditions set by the material used to manufacture the turbine blades. Hence, turbine blade cooling helps in drastically controlling the blade temperature of the turbine and allows a higher turbine inlet temperature. The blade could be cooled from the leading edge, from the entire surface of the blade or from the trailing edge. The various methods of blade cooling from leading edge and its comparative study were reviewed and summarized along with their advantages and disadvantages.

scholarly journals Cooling Process of Gas Turbine Blade: A Comparison Study

2020 ◽  
Vol 13 (3) ◽  
pp. 215-222
Author(s):  
Akram Luaibi Ballaoot ◽  
Naseer Hamza
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Power Output ◽  
Film Cooling ◽  
Aviation Industry ◽  
Inlet Temperature ◽  
Internal Cooling ◽  
Gas Turbine Blade ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet

The gas turbine engines are occupied an important sector in the energy production and aviation industry and this important increase day after day for their features. One of the most important parameters that limit the gas turbine engine power output is the turbine inlet temperature. The higher is the turbine inlet temperature, the higher is the power output or thrust but this increases of risks of blade thermal failure due to metallurgical limits. Thus the need for a good and efficient process of blade cooling can lead to the best compromise between a powerful engine and safe operation. There are two major methods: film or external cooling and internal cooling inside the blade itself. . In the past number of years there has been considerable progress in turbine cooling research and this paper is limited to review a few selected publications to reflect recent development in turbine blade film cooling. The maximum drop in the surface temperature of the gas turbine blade and associated thermal stress – due to incorporating cooling systems- were 735 ˚C, 1217 N/mm2 respectively.

A 2000-HP Military Vehicle Gas Turbine: A Study of Significant Thermodynamic and Mechanical Parameters

1968 ◽  
Author(s):  
A. F. Carter
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Overall Design ◽  
Blade Cooling ◽  
Turbine Inlet ◽  
Military Vehicle ◽  
Compressor Pressure Ratio ◽  
Selection Of

During a study of possible gas turbine cycles for a 2000-hp unit for tank propulsion, it has been established that the level of achievable specific fuel consumption (sfc) is principally determined by the combustor inlet temperature. If a regenerative cycle is selected, a particular value of combustor inlet temperature (and hence sfc) can be produced by an extremely large number of combinations of compressor pressure ratio, turbine inlet temperature, and heat exchanger effectiveness. This paper outlines the overall design considerations which led to the selection of a relatively low pressure ratio engine in which the turbine inlet temperature was sufficiently low that blade cooling was not necessary.

scholarly journals Optimum Power Boosting of Gas Turbine Cycles With Refrigerated Inlet Air and Compressor Intercooling

1996 ◽  
Author(s):  
Mohand A. Ait-Ali
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Turbine Blade Cooling ◽  
High Pressure Ratio ◽  
Blade Cooling ◽  
Air Inlet ◽  
Turbine Inlet ◽  
Compressor Work

With or without turbine blade cooling, gas turbine cycles have consistently higher turbine inlet temperatures than steam turbine cycles. But this advantage is more than offset by the excessive compressor work induced by warm inlet temperatures, particularly during operation on hot summer days. Instead of seeking still higher turbine inlet temperatures by means of sophisticated blade cooling technology and high temperature-resistant blade materials, it is proposed to greatly increase the cycle net work and also improve thermal efficiency by decreasing the compressor work. This is obtained by using refrigerated inlet air and compressor intercooling to an extent which optimizes the refrigerated air inlet temperature and consequently the gas turbine compression ratio with respect to maximum specific net power. The cost effectiveness of this conceptual cycle, which also includes regeneration, has not been examined in this paper as it requires unusually high pressure ratio gas turbines and compressors, as well as high volumetric air flow rate and low temperature refrigeration equipment for which reliable cost data is not easily available.

Impact on Cycle Efficiency of Small Combined Heat and Power Plants From Increasing Firing Temperature Enabled by Additive Manufacturing of Turbine Blades and Vanes

2021 ◽  
Author(s):  
Selcuk Can Uysal ◽  
Douglas Straub ◽  
James B. Black
Keyword(s):  
Gas Turbine ◽  
Firing Temperature ◽  
Turbine Blades ◽  
Internal Cooling ◽  
Cooling Effectiveness ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Percentage Points ◽  
Cycle Efficiency ◽  
The Impact

Abstract Using an analytical cooled gas turbine model and a steam cycle model, this study estimates the impact on combined heat and power (CHP) cycle performance from increasing the turbine firing temperature by 180°F (100°C) and improving the turbine blade cooling for a 6-MW scale gas turbine. A sensitivity analysis was performed to understand the impact of increasing the internal cooling effectiveness, thermal barrier coating performance, and blade material upgrades on gas turbine and CHP cycle efficiency. The impacts of turbine blade cooling improvements were studied for three common CHP cycle configurations identified from the literature. Various definitions for CHP cycle efficiency from the literature are used in the comparisons. The results show that a 180°F (100°C) increase in firing temperature can increase the gas turbine efficiency by 1 percentage point without improving cooling effectiveness and add 2 additional percentage points in efficiency by using advanced turbine blades with higher internal cooling efficiency. The engine upgrades evaluated in this study show potential for increasing the CHP cycle efficiency by 3 percentage points while increasing the steam generation rate by 8%.

Measured Effects of Flow Leakage on the Performance of the GT-225 Automotive Gas Turbine Engine

1980 ◽  
Vol 102 (1) ◽  
pp. 14-18 ◽  
Author(s):  
C. C. Matthews
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Performance Data ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Cold Surface ◽  
Turbine Engine ◽  
Turbine Inlet ◽  
Hot Surface

A GT-225 regenerative gas turbine engine was used to obtain engine performance data with varied rates of simulated internal leakage. Regenerator hot surface rim and crossarm seal leaks as well as regenerator cold surface seal leaks were simulated. Instrumentation was included in external ducting to measure the leakage rates. Data were taken at three gasifier turbine speeds with turbine inlet temperature held constant by means of the variable power turbine nozzle and also with varied turbine inlet temperatures resulting from operation with the nozzle fixed at the design area. Component performance data were calculated from the engine measurements to determine the loss mechanisms associated with the leakage. The GT-225 was most sensitive to hot surface rim seal leakage, followed closely by the hot surface crossarm seal leakage, and then the cold surface leakage. Performance was degraded much more when turbine inlet temperature was fixed (by about a factor of three for specific fuel consumption) than for the fixed geometry mode. The effects of leakage became less severe as gasifier turbine speed was increased. The engine performance deterioration due simply to the flow bypass is compounded by induced losses in regenerator and compressor performance leading to very large changes in engine performance, e.g., specific fuel consumption increased up to 80 percent and power decreased as much as 40 percent with 8 percent additional leakage.

Performance evaluation of a transpiration-cooled gas turbine for different coolants and permissible blade temperatures considering the effect of radiation

2011 ◽  
Vol 225 (8) ◽  
pp. 1156-1165 ◽  
Author(s):  
S Kumar ◽  
O Singh
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Radiation Effect ◽  
Turbine Blades ◽  
Cycle Performance ◽  
Inlet Temperature ◽  
Thermodynamic Evaluation ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Gas Turbine Cycle

Successful gas turbine technology is based significantly upon the introduction of new blade materials with increased permissible temperature for gas turbine blades and/or the use of efficient means and methods of turbine blade cooling in order to achieve the highest possible turbine inlet temperature. The gas turbine blade cooling models found in literature indicate that the effect of radiation from elevated temperature gases is generally not considered. However, the radiative heat transfer always occurs owing to the presence of mainly carbon dioxide and water vapour in the combustion products. The present paper deals with the comparative study of transpiration-cooled gas turbine cycle performance with and without taking radiation effect for different coolants and permissible blade temperature. The thermodynamic evaluation shows that, with consideration of the radiation effect, the theoretical coolant requirement increases so as to be close to the actual requirement and hence the cycle performance is affected accordingly. The transpiration-cooled gas turbine cycle performance parameter variations are presented to exemplify the role of cooling technology, cooling means, and material development, taking the radiation effect into account.

scholarly journals A Study on the Effect of Angle in Diffused Hole Film Cooling Effectiveness at Different Blowing Ratios

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nishant Gandhi ◽  
Suresh Sivan
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Cylindrical Hole ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Blowing Ratio ◽  
Turbine Inlet ◽  
Grid Independence

AbstractHigher the turbine inlet temperature of a gas turbine, higher will be the efficiency, however the increase in the turbine inlet temperature is limited to the materials and the cooling strategies employed. This article presents a study on the effect of blowing ratio on film cooling effectiveness for a cylindrical hole and a diffused hole at different angles. The analysis was done for blowing ratios of 0.5, 1.0, 1.5 and 2.0 while the angle in the diffused hole was varied as 5°, 10° and 15°. A grid independence study was performed and the simulation was validated. The results of cylindrical and different angles of diffused holes were compared. For a cylindrical hole as well as diffused hole, a blowing ratio of 1.0 was found to have an optimal effectiveness. The diffused hole was found to improve the near hole and downstream effectiveness at higher blowing ratios.

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