scholarly journals Effects of Some Key Parameters on the Overall Performance of Gas Turbine

2021 ◽  
Vol 10 (2) ◽  
pp. 37
Author(s):  
Pengfei Su ◽  
Jianmin Gao ◽  
Shiquan Zhao ◽  
Xiangling Kong ◽  
Yu Fang
Author(s):  
E. Benvenuti ◽  
B. Innocenti ◽  
R. Modi

This paper outlines parameter selection criteria and major procedures used in the PGT 25 gas turbine power spool aerodynamic design; significant results of the shop full-load tests are also illustrated with reference to both overall performance and internal flow-field measurements. A major aero-design objective was established as that of achieving the highest overall performance levels possible with the matching to latest generation aero-derivative gas generators; therefore, high efficiencies were set as a target both for the design point and for a wide range of operating conditions, to optimize the turbine’s uses in mechanical drive applications. Furthermore, the design was developed to reach the performance targets in conjunction with the availability of a nominal shaft speed optimized for the direct drive of pipeline booster centrifugal compressors. The results of the full-load performance testing of the first unit, equipped with a General Electric LM 2500/30 gas generator, showed full attainment of the design objectives; a maximum overall thermal efficiency exceeding 37% at nominal rating and a wide operating flexibility with regard to both efficiency and power were demonstrated.


Author(s):  
Oanh Nguyen ◽  
Scott Samuelsen

In view of increasingly stringent NOx emissions regulations on stationary gas turbines, lean combustion offers an attractive option to reduce reaction temperatures and thereby decrease NOx production. Under lean operation, however, the reaction is vulnerable to blowout. It is herein postulated that pilot hydrogen dopant injection, discretely located, can enhance the lean blowout performance without sacrificing overall performance. The present study addresses this hypothesis in a research combustor assembly, operated at atmospheric pressure, and fired on natural gas using rapid mixing injection, typical of commercial units. Five hydrogen injector scenarios are investigated. The results show that (1) pilot hydrogen dopant injection, discretely located, leads to improved lean blowout performance and (2) the location of discrete injection has a significant impact on the effectiveness of the doping strategy.


2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Ningbo Zhao ◽  
Xueyou Wen ◽  
Shuying Li

Coolant is one of the important factors affecting the overall performance of the intercooler for the intercooled (IC) cycle marine gas turbine. Conventional coolants, such as water and ethylene glycol, have lower thermal conductivity which can hinder the development of highly effective compact intercooler. Nanofluids that consist of nanoparticles and base fluids have superior properties like extensively higher thermal conductivity and heat transfer performance compared to those of base fluids. This paper focuses on the application of two different water-based nanofluids containing aluminum oxide (Al2O3) and copper (Cu) nanoparticles in IC cycle marine gas turbine intercooler. The effectiveness-number of transfer unit method is used to evaluate the flow and heat transfer performance of intercooler, and the thermophysical properties of nanofluids are obtained from literature. Then, the effects of some important parameters, such as nanoparticle volume concentration, coolant Reynolds number, coolant inlet temperature, and gas side operating parameters on the flow and heat transfer performance of intercooler, are discussed in detail. The results demonstrate that nanofluids have excellent heat transfer performance and need lower pumping power in comparison with base fluids under different gas turbine operating conditions. Under the same heat transfer, Cu–water nanofluids can reduce more pumping power than Al2O3–water nanofluids. It is also concluded that the overall performance of intercooler can be enhanced when increasing the nanoparticle volume concentration and coolant Reynolds number and decreasing the coolant inlet temperature.


Author(s):  
Jens Palsson ◽  
Azra Selimovic ◽  
Peter Hendriksen

Operational temperature around 800°C is desirable for solid oxide fuel cells (SOFC) due to alleviation of many serious problems, associated with high temperature, i.e., high degradation rate and cost of balance of plant components along with the need for expensive ceramic interconnect. This paper is concerned with the performance of hybrid cycles employing the intermedium temperature SOFC and a gas turbine. The calculations are performed with Aspen Plus® for a system in a size of 500 kW, using methane as fuel. The simulation tool is completed by a mathematical model of the fuel cell. Cell geometry is chosen to represent the type of cells developed at Risø National Laboratory. For the stand alone SOFC, introduction of the metallic interconnect gave an overall performance improvement. A maximum electric efficiency of more than 70% for the system was calculated at low pressure ratios.


Author(s):  
Lei Fu ◽  
Yan Shi ◽  
Qinghua Deng ◽  
Zhenping Feng

For millimeter-scale microturbines, the principal challenge is to achieve a design scheme to meet the aerothermodynamics, geometry restriction, structural strength and component functionality requirements while in consideration of the applicable materials, realizable manufacturing and installation technology. This paper mainly presents numerical investigations on the aerothermodynamic design, geometrical design and overall performance prediction of a millimeter-scale radial turbine with rotor diameter of 10mm. Four kinds of turbine rotor profiles were designed, and they were compared with one another in order to select the suitable profile for the micro radial turbine. The leaving velocity loss in micro gas turbines was found to be a large source of inefficiency. The approach of refining the geometric structure of rotor blades and the profile of diffuser were adopted to reduce the exit Mach number thus improving the total-static efficiency. Different from general gas turbines, micro gas turbines are operated in low Reynolds numbers, 104∼105, which has significant effect on flow separation, heat transfer and laminar to turbulent flow transition. Based on the selected rotor profile, several micro gas turbine configurations with different tip clearances of 0.1mm, 0.2mm and 0.3mm, respectively; two different isothermal wall conditions; and two laminar-turbulent transition models were investigated to understand the particular influence of low Reynolds number. These influences on the overall performance of the micro gas turbine were analyzed in details. The results indicate that these configurations should be included and emphasized during the design process of the millimeter-scale micro radial turbines.


Author(s):  
Mirko Morini ◽  
Michele Pinelli ◽  
Pier Ruggero Spina ◽  
Mauro Venturini

Gas turbine performance degradation over time is mainly due to the deterioration of compressor and turbine blades, which, in turn, causes a modification of the compressor and turbine performance maps. Since detailed information about the actual modification of the compressor and turbine performance maps is usually unavailable, component performance can be modeled and investigated (i) by scaling the overall performance map, or (ii) by using stage-by-stage models of the compressor and turbine and by scaling each single stage performance map to account for each stage deterioration, or (iii) by performing 3D numerical simulations, which allow to both highlight the fluid-dynamic phenomena occurring in the faulty component and grasp the effect on the overall performance of the component. In this paper, the authors address the most common and experienced source of loss for a gas turbine, i.e. compressor fouling. With respect to the traditional approach, which mainly aims at the identification of the overall effects of fouling, authors investigate a micro-scale representation of compressor fouling (e.g. blade surface deterioration and flow deviation). This allows (i) a more detailed investigation of the fouling effects (e.g. mechanism, location along blade height, etc.), (ii) a more extensive analysis of the causes of performance deterioration and (iii) the assessment of the effect of fouling on stage performance coefficients and on stage performance maps. The effects of a non-uniform surface roughness on both rotor and stator blades of an axial compressor stage are investigated by using a commercial CFD code. The NASA Stage 37 test case was used as the baseline geometry. The numerical model already validated against experimental data available in literature was used for the simulations. Different non-uniform combinations of surface roughness levels on rotor and stator blades were imposed. This makes it possible to highlight how the localization of fouling on compressor blades affects compressor performance, both at an overall and at a fluid-dynamic level.


Author(s):  
K. Mathioudakis ◽  
A. Stamatis ◽  
E. Bonataki

A method for diagnosing which parts of a Combined Cycle Gas Turbine (CCGT) power plant are responsible for performance deviations is presented. When the overall power output and efficiency deviate from their baseline value, application of the method allows the determination of the component(s) of the plant, responsible for this deviation. The level of depth of this assessment depends on the number of quantities measured. It is demonstrated that a minimal number of measurements can be used to allocate differences between the gas turbine and the steam part of the plant. Additional data can then be used to identify deviating components in more detail. The influence of measurement uncertainty and the exploitation of different measurements in order to check consistency and improve reliability of the results are discussed.


1982 ◽  
Author(s):  
H. Vandermeulen

The basic distinction between the constant volume cycle and the well known constant pressure cycle for gas turbines is the method of heat supply, which necessitates a system of combustion chamber valves to contain the fluid. The object of the proposed cycle analysis, which is mainly based on the fundamental laws of mass and energy, will consider a solution for the discrepancies between the former theory and practice of constant volume gas turbines. The overall performance characteristics which emerge from this analysis show the distinct superiority of the one-valve Karavodine cycle. Evaluation by experiment for this cycle variant shows, however, besides a refinement of the model, a marginal superiority in performance for the Brayton gas turbine at low pressure ratios. Any application could probably be justified by incorporating it in Brayton turbines to diminish starting power and to improve part load performance.


Author(s):  
Shaun Hatcher ◽  
Tom Batory ◽  
Robert Neff ◽  
Pat Kane

This report is a comprehensive document citing the events pertaining to the qualification of the GE LM2500+ gas turbine engine for US Navy Service. The purpose of this report is to serve as documentation of the entire Qualification process that includes the 500-hour Rating Qualification Test and subsequent teardown inspection, High Impact Shock Testing, and the subsequent 100-hour post shock endurance test and teardown inspection. This report includes an assessment of the overall performance of the engine, General Electric’s capacity to meet specified test requirements, any questions or concerns that may have arisen during testing, and a conclusive statement about the outcome of the tests.


Sign in / Sign up

Export Citation Format

Share Document