Enhancements to the Load Acceptance and Rejection Capability of a High Pressure Aeroderivative Engine

Author(s):  
Brian Price ◽  
Louis Demers ◽  
Jean-Francois Lebel ◽  
Sylvain Bonneville

This paper describes improvements to the control of a high pressure, aeroderivative industrial gas turbine in order to better accommodate rapid load changes. In such circumstances it is important to maintain the speed of the driven equipment within an acceptable range. This can require the gas turbine to quickly adjust to the new load, to minimize the power imbalance, which is the cause of the speed variation. The paper describes the theory behind control schedules required to achieve this, and how they relate to avoiding surge, flameout or instability, while minimizing speed variations of the driven equipment. A whole engine thermodynamic model coupled to the control software was used to simulate the engine response during these rapid transients. The features of this model are described. The model allowed optimization of the control software in advance of the engine test. Results of whole engine tests are presented and compared to the model; and the types of load steps that remain most challenging are highlighted. The resulting capability remains partly determined by the specifics of the application, for example the inertia of the driven equipment, the nominal speed of operation, and the allowable speed variations. The effects of these can be predicted using the model and are discussed.

1997 ◽  
Vol 119 (3) ◽  
pp. 506-511 ◽  
Author(s):  
I. Yuri ◽  
T. Hisamatsu ◽  
K. Watanabe ◽  
Y. Etori

A ceramic combustor for a 1500°C, 20 MW class industrial gas turbine was developed and tested. This combustor has a hybrid ceramic/metal structure. To improve the durability of the combustor, the ceramic parts were made of silicon carbide (SiC), which has excellent oxidation resistance under high-temperature conditions as compared to silicon nitride (Si3N4), although the fracture toughness of SiC is lower than that of Si3N4. Structural improvements to allow the use of materials with low fracture toughness were made to the fastening structure of the ceramic parts. Also, the combustion design of the combustor was improved. Combustor tests using low-Btu gaseous fuel of a composition that simulated coal gas were carried out under high pressure. The test results demonstrated that the structural improvements were effective because the ceramic parts exhibited no damage even in the fuel cutoff tests from rated load conditions. It also indicated that the combustion efficiency was almost 100 percent even under part-load conditions.


Author(s):  
Koji Terauchi ◽  
Daisuke Kariya ◽  
Seiichirou Maeda ◽  
Kenichirou Yoshiura

Outlined in this paper are the details of redesign of an 11-stage axial compressor for 18MW class industrial gas turbine. Although the design value of adiabatic efficiency is 85%, the efficiency achieved in the prototype engine test was 1 point short of the target. According to the test results and CFD analyses, it was estimated that the stage mismatching due to an excessive work of intermediate stages was a major cause of the losses. To improve the matching, redesign of airfoils were carried out to some blades and vanes. The results of Multistage CFD showed that the matching was improved and the efficiency was increased, which was also confirmed by the engine test.


Author(s):  
I. Yuri ◽  
T. Hisamatsu ◽  
K. Watanabe ◽  
Y. Etori

A ceramic combustor for a 1500°C, 20MW class industrial gas turbine was developed and tested. This combustor has a hybrid ceramic/metal structure. To improve the durability of the combustor, the ceramic parts were made of silicon carbide (SiC), which has excellent oxidation resistance under high temperature conditions as compared to silicon nitride (Si3N4) although the fracture toughness of SiC is lower than that of Si3N4. Structural improvements to allow the use of materials with low fracture toughness, were made to the fastening structure of the ceramic parts. Also the combustion design of the combustor was improved. Combustor tests using low BTU gaseous fuel of a composition that simulated coal gas were carried out under high pressure. The test results demonstrated that the structural improvements were effective because the ceramic parts exhibited no damage even in the fuel cutoff tests from rated load conditions. It also indicated that the combustion efficiency was almost 100% even under part load conditions.


1993 ◽  
Author(s):  
S. Amagasa ◽  
K. Shimomura ◽  
M. Kadowaki ◽  
K. Takeishi ◽  
H. Kawai ◽  
...  

This paper describes the summary of a three year development program for the 1st stage stationary vane and rotating blade for the next generation, 1500°C Class, high efficiency gas turbine. In such a high temperature gas turbine, the 1st turbine vane and blade are the most important hot parts. Full coverage film cooling (FCFC) is adopted for the cooling scheme, and directionally solidified (DS) nickel base super-alloy and thermal barrier coating (TBC) will be used to prolong the creep and thermal fatigue life. The concept of the cooling configuration, fundamental cascade test results and material test results will be presented.


Author(s):  
Girish M. Shejale ◽  
David Ross

The 1st stage buckets in Frame 3002, 10 MW industrial gas turbine experienced premature failures. The buckets failed unexpectedly much earlier than the designed bucket life. Bucket material is Inconel 738, with platinum-aluminized coating on the surface. Failure investigation of the buckets was performed to know the root cause of the failure. The failure investigation primarily comprised of metallurgical investigation. The results of the metallurgical investigation were co-related with the unit operational history. This paper provides an overview of 1st stage buckets investigation. The metallurgical investigation performed concluded prime failure mechanism due to high carbon content of bucket material and improper heat treatment. The bucket coating was initially damaged during the first loading and fracture occurred due to grain boundary embrittlement in short span of service. The metallurgical tests performed included Visual inspection, Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-ray (EDS), Chemical analysis, Tensile test and Hardness survey. The test results, discussions and conclusions are presented in this paper.


1999 ◽  
Vol 121 (3) ◽  
pp. 422-428 ◽  
Author(s):  
Y. Ozawa ◽  
Y. Tochihara ◽  
N. Mori ◽  
I. Yuri ◽  
T. Kanazawa ◽  
...  

A catalytically assisted ceramic combustor for a gas turbine was designed to achieve low NOx emission under 5 ppm at a combustor outlet temperature over 1300°C. This combustor is composed of a burner system and a ceramic liner behind the burner system. The burner system consists of 6 catalytic combustor segments and 6 premixing nozzles, which are arranged in parallel and alternately. The ceramic liner is made up of the layer of outer metal wall, ceramic fiber, and inner ceramic tiles. Fuel flow rates for the catalysts and the premixing nozzles are controlled independently. Catalytic combustion temperature is controlled under 1000°C, premixed gas is injected from the premixing nozzles to the catalytic combustion gas and lean premixed combustion over 1300°C is carried out in the ceramic liner. This system was designed to avoid catalytic deactivation at high temperature and thermal and mechanical shock fracture of the honeycomb monolith of the catalyst. A combustor for a 10 MW class, multican type gas turbine was tested under high pressure conditions using LNG fuel. Measurements of emission, temperature, etc. were made to evaluate combustor performance under various combustion temperatures and pressures. This paper presents the design features and the test results of this combustor.


Author(s):  
Colin Rodgers ◽  
Dan Brown

Three 140mm tip diameter centrifugal compressors were designed and tested to determine the one exhibiting the best performance most suitable for eventual application to a small 60KW radial flow type gas turbine. The design features, and stage test results of these three moderately high pressure ratio impellers are presented, together with a comparison of their respective test and CFD computed performance maps.


Author(s):  
Mohan K. Razdan ◽  
Jacob T. McLeroy ◽  
William E. Weaver

This paper describes progress in the development of a 25 ppm NOx combustor that requires no diluent injection or post-combustion treatment The combustor will be retrofittable in all existing Allison Model 501-K series industrial engines. The approach undertaken is based on lean-premix combustion design incorporating an efficient fuel and air pre-mixing, fuel staging, and advanced wall cooling. Extensive use has been made of Computational Combustor Dynamics (CCD) codes in the design of the low NOx combustor. Experimental work in support of the present effort includes atmospheric bench scale testing and high pressure rig testing. The bench tests have been performed to evaluate several candidate designs, to gain better understanding of general lean pre-mixed combustor behavior, and to verify model predictions. The bench test results have indicated good fuel/air mixing performance of the lean premixing domes. The high pressure simulated engine rig tests of the dry lean pre-mixed low emissions combustors using natural gas have demonstrated NOx levels less than 15 ppm vd (15% O2 corrected), well below the program goals.


Author(s):  
R. C. Petitt

This paper describes the design and development of a new series 3000 two-shaft regenerative and simple cycle gas turbine for mechanical drive applications. Technical advances in the areas of aero-thermal, mechanical, controls, and materials design were combined to produce a machine with a regenerative cycle thermal efficiency of 32%. Increased automation and adaptability to remote control were provided by a new solid state control system and high pressure hydraulics.


1998 ◽  
Vol 120 (3) ◽  
pp. 509-513 ◽  
Author(s):  
T. Fujii ◽  
Y. Ozawa ◽  
S. Kikumoto ◽  
M. Sato ◽  
Y. Yuasa ◽  
...  

Recently, the use of gas turbine systems, such as combined cycle and cogeneration systems, has gradually increased in the world. But even when a clean fuel such as LNG (liquefied natural gas) is used, thermal NOx is generated in the high temperature gas turbine combustion process. The NOx emission from gas turbines is controlled through selective catalytic reduction processes (SCR) in the Japanese electric industry. If catalytic combustion could be applied to the combustor of the gas turbine, it is expected to lower NOx emission more economically. Under such high temperature and high pressure conditions, as in the gas turbine, however, the durability of the catalyst is still insufficient. So it prevents the realization of a high temperature catalytic combustor. To overcome this difficulty, a catalytic combustor combined with premixed combustion for a 1300°C class gas turbine was developed. In this method, catalyst temperature is kept below 1000°C, and a lean premixed gas is injected into the catalytic combustion gas. As a result, the load on the catalyst is reduced and it is possible to prevent the catalyst deactivation. After a preliminary atmospheric test, the design of the combustort was modified and a high pressure combustion test was conducted. As a result, it was confirmed that NOx emission was below 10 ppm (at 16 percent O2) at a combustor outlet gas temperature of 1300°C and that the combustion efficiency was almost 100 percent. This paper presents the design features and test results of the combustor.


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