A Detailed Modular Governor-Turbine Model for Multiple-Spool Gas Turbine With Scrutiny of Bleeding Effect

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Hossein Balaghi Enalou ◽  
Eshagh Abbasi Soreshjani ◽  
Mohamed Rashed ◽  
Seang Shen Yeoh ◽  
Serhiy Bozhko
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Control Design ◽  
Electric Utility ◽  
Test Results ◽  
Feedback Control System ◽  
Bleeding Effect ◽  
Power Turbine ◽  
Reliable Model ◽  
Volume Method

Multiple-spool gas turbines are usually utilized for power supply in aircrafts, ships, and terrestrial electric utility plants. As a result, having a reliable model of them can aid with the control design process and stability analysis. Since several interconnected components are coupled both thermodynamically and through shafts, these engines cannot be modeled linearly as single shaft gas turbines. In this paper, intercomponent volume method (ICV) has been implemented for turbine modeling. A switched feedback control system incorporating bump-less transfer and antiwindup functionality is employed as governor for the engine. Validation with test results from a three spool gas turbine highlights high accuracy of turbine-governor model in various maneuvers. Results show that over-speed after load rejection is considerable due to the fact that in this arrangement, the power turbine (PT) is not coupled with the compressor which acts like a damper for single shaft gas turbines. To address this problem, bleed valves (mainly before combustion chamber) are used to arrest the over-speed by 20%. In addition, a switch is employed into the governor system to rapidly shift fuel to permissible minimum flow.

scholarly journals FT8-55 Mechanical Drive Aeroderivative Gas Turbine: Design of Power Turbine and Full-Load Test Results

1994 ◽  
Author(s):  
E. Aschenbruck ◽  
R. Blessing ◽  
L. Turanskyj
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Material Selection ◽  
Measurement Techniques ◽  
Load Test ◽  
Civil Aviation ◽  
Test Results ◽  
Full Load ◽  
Highly Efficient ◽  
Power Turbine

A new, highly efficient 25-MW aero-derivative gas turbine, model FT8-55, has been developed for mechanical drive applications as a member of the FT8 gas turbine family which also includes two generator drive gas turbines, models FT8-30 and FT8-36, with power turbine speeds of 3000 rpm and 3600 rpm, respectively. For the new mechanical drive version FT8-55, the power turbine can be operated up to 5775 rpm at maximum continuous speed. All power turbines are equipped with gas generators, model GG8-1, which are derived from the most popular aero-engine in civil aviation, the JT8D. The first part of this paper describes design features, rotor dynamics, and material selection for the three-stage power turbine PT8-55. Rotor design permits unrestricted operation in the speed range from 2500 rpm up to maximum continuous speed. The first FT8-55 gas turbine was subjected to mechanical and performance workshop tests at different speeds and power outputs up to full-load. The second part of the paper deals with the description of the test stand arrangement for testing complete gas turbine packages as well as measurement techniques and data evaluation. Power was absorbed by a two-stage pipeline compressor, equipped with magnetic bearings and dry gas seals, which was operated in a closed loop. Thermodynamic and mechanical test results at various speeds and loads provide evidence of a highly efficient and mechanically robust gas turbine for mechanical drive applications.

A Control System for a High-Quality Generating Set Equipped With a Two-Shaft Gas Turbine

1991 ◽  
Vol 113 (2) ◽  
pp. 290-295 ◽  
Author(s):  
H. Kumakura ◽  
T. Matsumura ◽  
E. Tsuruta ◽  
A. Watanabe
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Quality ◽  
Constant Frequency ◽  
Generating Set ◽  
Generating Sets ◽  
Power Turbine ◽  
Computer Centers ◽  
Supply Systems

A control system has been developed for a high-quality generating set (150-kW) equipped with a two-shaft gas turbine featuring a variable power turbine nozzle. Because this generating set satisfies stringent frequency stability requirements, it can be employed as the direct electric power source for computer centers without using constant-voltage, constant-frequency power supply systems. Conventional generating sets of this kind have normally been powered by single-shaft gas turbines, which have a larger output shaft inertia than the two-shaft version. Good frequency characteristics have also been realized with the two-shaft gas turbine, which provides superior quick start ability and lower fuel consumption under partial loads.

Development and Fabrication of Silicon Nitride Components for Ceramic Gas Turbine

1997 ◽  
Author(s):  
Keisuke Makino ◽  
Ken-Ichi Mizuno ◽  
Toru Shimamori
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Blades ◽  
High Strength ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Spark Plug ◽  
Power Turbine

NGK Spark Plug Co., Ltd. has been developing various silicon nitride materials, and the technology for fabricating components for ceramic gas turbines (CGT) using theses materials. We are supplying silicon nitride material components for the project to develop 300 kW class CGT for co-generation in Japan. EC-152 was developed for components that require high strength at high temperature, such as turbine blades and turbine nozzles. In order to adapt the increasing of the turbine inlet temperature (TIT) up to 1,350 °C in accordance with the project goals, we developed two silicon nitride materials with further unproved properties: ST-1 and ST-2. ST-1 has a higher strength than EC-152 and is suitable for first stage turbine blades and power turbine blades. ST-2 has higher oxidation resistance than EC-152 and is suitable for power turbine nozzles. In this paper, we report on the properties of these materials, and present the results of evaluations of these materials when they are actually used for CGT components such as first stage turbine blades and power turbine nozzles.

Flow Interactions Between Shrouded Power Turbine and Nonaxisymmetric Exhaust Volute for Marine Gas Turbines

2017 ◽  
Author(s):  
Jie Gao ◽  
Feng Lin ◽  
Xiying Niu ◽  
Qun Zheng ◽  
Guoqiang Yue ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Rotor Blade ◽  
Exhaust System ◽  
Computational Domain ◽  
Local Flow ◽  
Power Turbine ◽  
Flow Interactions ◽  
Shrouded Rotor ◽  
Turbine Exhaust

The marine gas turbine exhaust volute is an important component that connects a power turbine and an exhaust system, and it is of great importance to the overall performance of the gas turbine. Gases exhausted from the power turbine are expanded and deflected 90 degrees in the exhaust volute, and then discharge radially into the exhaust system. The flows in the power turbine and the nonaxisymmetric exhaust volute are closely coupled and inherently unsteady. The flow interactions between the power turbine and the exhaust volute have a significant influence on the shrouded rotor blade aerodynamic forces. However, the interactions have not been taken into account properly in current power turbine design approaches. The present study aims to investigate the flow interactions between the last stage of a shrouded power turbine and the nonaxisymmetric exhaust volute with struts. Special attention is given to the coupled aerodynamics and pressure response studies. This work was carried out using coupled computational fluid dynamics (CFD) simulations with the computational domain including a stator vane, 76 shrouded rotor blades, 9 struts and an exhaust volute. Three-dimensional (3D) unsteady and steady Reynolds-averaged Navier-Stokes (RANS) solutions in conjunction with a Spalart-Allmaras turbulence model are utilized to investigate the aerodynamic characteristics of shrouded rotors and an exhaust volute using a commercial CFD software ANSYS Fluent 14.0. The asymmetric flow fields are analyzed in detail; as are the unsteady pressures on the shrouded rotor blade. In addition, the unsteady total pressures at the volute outlet is also analyzed without consideration of the upstream turbine effects. Results show that the flows in the nonaxisymmetric exhaust volute are inherently unsteady; for the studied turbine-exhaust configuration the nonaxisymmetric back-pressure induced by the downstream volute leads to the local flow varying for each shrouded blade and low frequency fluctuations in the blade force. Detailed results from this investigation are presented and discussed in this paper.

Rolls Royce/Allison 501-K Gas Turbine Anti-Fouling Compressor Coatings Evaluation

2002 ◽  
Author(s):  
Daniel E. Caguiat
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Gas Turbines ◽  
Performance Degradation ◽  
Specific Fuel Consumption ◽  
Inlet Temperature ◽  
Test Results ◽  
Turbine Inlet ◽  
Compressor Performance ◽  
Compressor Efficiency

The Naval Surface Warfare Center, Carderock Division (NSWCCD) Gas Turbine Emerging Technologies Code 9334 was tasked by NSWCCD Shipboard Energy Office Code 859 to research and evaluate fouling resistant compressor coatings for Rolls Royce Allison 501-K Series gas turbines. The objective of these tests was to investigate the feasibility of reducing the rate of compressor fouling degradation and associated rate of specific fuel consumption (SFC) increase through the application of anti-fouling coatings. Code 9334 conducted a market investigation and selected coatings that best fit the test objective. The coatings selected were Sermalon for compressor stages 1 and 2 and Sermaflow S4000 for the remaining 12 compressor stages. Both coatings are manufactured by Sermatech International, are intended to substantially decrease blade surface roughness, have inert top layers, and contain an anti-corrosive aluminum-ceramic base coat. Sermalon contains a Polytetrafluoroethylene (PTFE) topcoat, a substance similar to Teflon, for added fouling resistance. Tests were conducted at the Philadelphia Land Based Engineering Site (LBES). Testing was first performed on the existing LBES 501-K17 gas turbine, which had a non-coated compressor. The compressor was then replaced by a coated compressor and the test was repeated. The test plan consisted of injecting a known amount of salt solution into the gas turbine inlet while gathering compressor performance degradation and fuel economy data for 0, 500, 1000, and 1250 KW generator load levels. This method facilitated a direct comparison of compressor degradation trends for the coated and non-coated compressors operating with the same turbine section, thereby reducing the number of variables involved. The collected data for turbine inlet, temperature, compressor efficiency, and fuel consumption were plotted as a percentage of the baseline conditions for each compressor. The results of each plot show a decrease in the rates of compressor degradation and SFC increase for the coated compressor compared to the non-coated compressor. Overall test results show that it is feasible to utilize anti-fouling compressor coatings to reduce the rate of specific fuel consumption increase associated with compressor performance degradation.

scholarly journals An Empirical Approach to the Preliminary Design of a Closed Cycle Gas Turbine

1998 ◽  
Author(s):  
R. P. op het Veld ◽  
J. P. van Buijtenen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
State Of The Art ◽  
Preliminary Design ◽  
Power Turbine ◽  
Helium Gas ◽  
Source State ◽  
High Temperature Reactor ◽  
The Cost

This paper investigates the layout and achievable efficiencies of rotating components of a Helium gas turbine. This is done by making a preliminary design of the compressor and turbine needed for the power conversion in a combined heat and power plant with a 40 MWth nuclear high temperature reactor as a heat source. State of the art efficiency values of air breathing gas turbines are used for the first calculations. The efficiency level is corrected by comparing various dimensionless data of the Helium turbomachine with an air gas turbine of similar dimensions. A single shaft configuration with a high speed axial turbine will give highest performance and simple construction. If a generator has to be driven at a conventional speed, a free power turbine configuration must be chosen. The choice of the configuration depends among others on the cost and availability of the asynchrone generator and frequency convertor.

Capacity Matching of Aeroderivative Gas Generator With Free Power Turbine: Challenges, Uncertainties, and Opportunities

2019 ◽  
Author(s):  
Deepak Thirumurthy ◽  
Jose Carlos Casado Coca ◽  
Kanishka Suraweera
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Systems Approach ◽  
Gas Generator ◽  
Performance Guarantees ◽  
Design Variables ◽  
Performance Trends ◽  
Power Turbine ◽  
Parameter Matching ◽  
Turbine Capacity

Abstract For gas turbines with free power turbines, the capacity or flow parameter matching is of prime importance. Accurately matched capacity enables the gas turbine to run at its optimum conditions. This ensures maximum component efficiencies, and optimum shaft speeds within mechanical limits. This paper presents the challenges, uncertainties, and opportunities associated with an accurate matching of a generic two-shaft aeroderivative HP-LP gas generator with the free power turbine. Additionally, generic performance trends, uncertainty quantification, and results from the verification program are also discussed. These results are necessary to ensure that the final free power turbine capacity is within the allowable range and hence the product meets the performance guarantees. The sensitivity of free power turbine capacity to various design variables such as the vane throat area, vane trailing edge size, and manufacturing tolerance is presented. In addition, issues that may arise due to not meeting the target capacity are also discussed. To conclude, in addition to design, analysis, and statistical studies, a system-of-systems approach is mandatory to meet the allowed variation in the free power turbine capacity and hence the desired gas turbine performance.

Biomass-Gasifier Steam-Injected Gas Turbine Cogeneration

1990 ◽  
Vol 112 (2) ◽  
pp. 157-163 ◽  
Author(s):  
E. D. Larson ◽  
R. H. Williams
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Sugar Industry ◽  
Low Cost ◽  
Forest Products ◽  
Steam Injection ◽  
Electric Utility ◽  
Cane Sugar ◽  
Commercial Viability ◽  
Potential Applications

Steam injection for power and efficiency augmentation in aeroderivative gas turbines is now commercially established for natural gas-fired cogeneration. Steam-injected gas turbines fired with coal and biomass are being developed. In terms of efficiency, capital cost, and commercial viability, the most promising way to fuel steam-injected gas turbines with biomass is via the biomass-integrated gasifier/steam-injected gas turbine (BIG/STIG). The R&D effort required to commercialize the BIG/STIG is modest because it can build on extensive previous coal-integrated gasifier/gas turbine development efforts. An economic analysis of BIG/STIG cogeneration is presented here for cane sugar factories, where sugar cane residues would be the fuel. A BIG/STIG investment would be attractive for sugar producers, who could sell large quantities of electricity, or for the local electric utility, as a low-cost generating option. Worldwide, the cane sugar industry could support some 50,000 MW of BIG/STIG capacity, and there are many potential applications in the forest products and other biomass-based industries.

scholarly journals Conceptual Mean-Line Design of Single and Twin-Shaft Oxy-Fuel Gas Turbine in a Semiclosed Oxy-Fuel Combustion Combined Cycle

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Majed Sammak ◽  
Egill Thorbergsson ◽  
Tomas Grönstedt ◽  
Magnus Genrup
Keyword(s):  
Mach Number ◽  
Gas Turbine ◽  
Mass Flow ◽  
Rotational Speed ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Fuel Gas ◽  
Power Turbine ◽  
Exit Mach Number ◽  
Line Design

The aim of this study was to compare single- and twin-shaft oxy-fuel gas turbines in a semiclosed oxy-fuel combustion combined cycle (SCOC–CC). This paper discussed the turbomachinery preliminary mean-line design of oxy-fuel compressor and turbine. The conceptual turbine design was performed using the axial through-flow code luax-t, developed at Lund University. A tool for conceptual design of axial compressors developed at Chalmers University was used for the design of the compressor. The modeled SCOC–CC gave a net electrical efficiency of 46% and a net power of 106 MW. The production of 95% pure oxygen and the compression of CO2 reduced the gross efficiency of the SCOC–CC by 10 and 2 percentage points, respectively. The designed oxy-fuel gas turbine had a power of 86 MW. The rotational speed of the single-shaft gas turbine was set to 5200 rpm. The designed turbine had four stages, while the compressor had 18 stages. The turbine exit Mach number was calculated to be 0.6 and the calculated value of AN2 was 40 · 106 rpm2m2. The total calculated cooling mass flow was 25% of the compressor mass flow, or 47 kg/s. The relative tip Mach number of the compressor at the first rotor stage was 1.15. The rotational speed of the twin-shaft gas generator was set to 7200 rpm, while that of the power turbine was set to 4800 rpm. A twin-shaft turbine was designed with five turbine stages to maintain the exit Mach number around 0.5. The twin-shaft turbine required a lower exit Mach number to maintain reasonable diffuser performance. The compressor turbine was designed with two stages while the power turbine had three stages. The study showed that a four-stage twin-shaft turbine produced a high exit Mach number. The calculated value of AN2 was 38 · 106 rpm2m2. The total calculated cooling mass flow was 23% of the compressor mass flow, or 44 kg/s. The compressor was designed with 14 stages. The preliminary design parameters of the turbine and compressor were within established industrial ranges. From the results of this study, it was concluded that both single- and twin-shaft oxy-fuel gas turbines have advantages. The choice of a twin-shaft gas turbine can be motivated by the smaller compressor size and the advantage of greater flexibility in operation, mainly in the off-design mode. However, the advantages of a twin-shaft design must be weighed against the inherent simplicity and low cost of the simple single-shaft design.

Analysis of the Dynamics of Gas Turbines and Their Control Systems

1971 ◽  
Vol 93 (3) ◽  
pp. 300-306 ◽  
Author(s):  
L. B. Sarantsev
Keyword(s):  
Control Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Metallurgical Industry ◽  
Power Turbine ◽  
Protection Systems ◽  
Heat Regeneration ◽  
Complete Set ◽  
Open Cycle

The gas turbine units designed by the Neva Works named after V. I. Lenin (NZL) are intended for driving the gas trunkline compressors and electrical generators, and are also used in chemical and metallurgical industry for heat recovery. By July 1, 1969, 320 gas turbines manufactured by NZL had operated under load more than 4.5 million hr and produced over 20 million MWH. Two-shaft and single-shaft gas turbine units manufactured by the NZL are intended for open cycle operation with heat regeneration. The two-shaft arrangements are designed and built to operate with a free power turbine. The specifications for these gas turbine units are given in Table 1. The modern gas turbine units are equipped with control and protection systems which accomplish the automatic control of the unit at its starting and stopping as well as its operating duties. The hydraulic, pneumatic, and electric instruments and regulators are widely used in these systems. The indication and recording of main parameters of the unit are performed by a complete set of these instruments.

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