Influence of the Control Logic on Gas Turbine Operation

1997 ◽  
Author(s):  
R. Bettocchi ◽  
P. R. Spina
Keyword(s):  
Gas Turbine ◽  
Thermal Power ◽  
Maximum Efficiency ◽  
Outlet Temperature ◽  
Control Parameters ◽  
Control Logic ◽  
Surge Margin ◽  
Power Turbine ◽  
Variable Power ◽  
And Control

This paper presents an analysis of the influence of control logic on gas turbine operation, when machine load adjustments are carried out. An examination is made of the control logics that are possible for a two-shaft gas turbine with variable power turbine nozzle in order to reach the following objectives: - operation in maximum efficiency conditions; - operation in the conditions of maximum thermal power of exhaust gases at the turbine outlet; - operation at constant turbine outlet temperature; - operation with the maximum Surge Margin. The control logics necessary for reaching the predetermined objectives in the part-load operation are provided by the map of gas turbine’s main performance, thermodynamic and control parameters.

Intercooled/Recuperated Shipboard Generator Drive Engine

1986 ◽  
Author(s):  
R. G. Mills ◽  
K. W. Karstensen
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Gas Turbines ◽  
Electrical Power ◽  
Specific Fuel Consumption ◽  
Fire Control ◽  
Load Range ◽  
Light Load ◽  
Power Turbine ◽  
Variable Power

Adverse consequences of losing electrical power to complex electronic and fire control equipment, or of the sudden variations of shore power, cause naval combatants to operate two generators most of the time, each at light load where specific fuel consumption of simple-cycle gas turbines is particularly high. The recuperated gas turbine with variable power-turbine nozzles has a much better specific fuel consumption, especially at part load. Herein described is a compact recuperated gas turbine with variable power-turbine nozzles designed for marine and industrial use, suitable with or without intercooling. These features yield a specific fuel consumption that is comparable to marine diesels used for generator drive, and essentially flat across the entire usable load range.

Simulation of startup operation of an industrial twin-shaft gas turbine based on geometry and control logic

Energy ◽  
2019 ◽  
Vol 183 ◽  
pp. 1295-1313 ◽  
Author(s):  
Poorya Keshavarz Mohammadian ◽  
Mohammad Hassan Saidi
Keyword(s):  
Gas Turbine ◽  
Control Logic ◽  
And Control

Simulation of an Innovative Startup Phase for SOFC Hybrid Systems Based on Recompression Technology: Emulator Test Rig

2015 ◽  
Vol 12 (4) ◽  
Author(s):  
U. M. Damo ◽  
M. L. Ferrari ◽  
A. Turan ◽  
A. F. Massardo
Keyword(s):  
Fuel Cell ◽  
Hybrid Systems ◽  
Outlet Temperature ◽  
Test Rig ◽  
Control Logic ◽  
Transient Model ◽  
Fuel Flow ◽  
Research Activities ◽  
Surge Margin ◽  
Efficiency Increase

This paper presents a novel startup approach for solid oxide fuel cell (SOFC) hybrid systems (HSs) based on recompression technology. This startup approach shows a novel method of managing a complete plant to obtain better performance, which is always also a difficult task for equipment manufactures. The research activities were carried out using the HS emulator rig located in Savona (Italy) and developed by the Thermochemical Power Group (TPG) of the University of Genoa. The test rig consists of three integrated technologies: a 100 kWe recuperated microturbine modified for external connections, a high temperature modular vessel necessary to emulate the dimensions of an SOFC stack, and, for air recompression, a turbocharger necessary to increase fuel cell pressure (using part of the recuperator outlet flow) as required for efficiency increase and to manage the cathodic recirculation. It was necessary to develop a theoretical model in order to prevent abnormal plant startup conditions as well as motivated by economic considerations. This transient model of the emulator rig was developed using Matlab®-Simulink® environment to study the time-dependent (including the control system aspects) behavior during the entire system (emulator equipped with the turbocharger) startup condition. The results obtained were able to demonstrate that the HS startup phase can be safely managed with better performance developing a new control logic. In detail, the startup phase reported in this paper shows that all important parameters were always inside acceptable operating zones (surge margin kept above 1.1, turbine outlet temperature (TOT), and fuel flow maintained lower than 918.15 K and 7.7 g/s, respectively).

Off-Design Performance Investigation of a Low Calorific Gas Fired Two-Shaft Gas Turbine

2009 ◽  
Author(s):  
Pontus Eriksson ◽  
Magnus Genrup ◽  
Klas Jonshagen ◽  
Jens Klingmann
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Gas Generator ◽  
Dimensional Parameter ◽  
Gaseous Fuels ◽  
Surge Margin ◽  
Power Turbine ◽  
Lean Premixed ◽  
Wobbe Index ◽  
Compressor Map

Gas turbine systems are predominantly designed to be fuelled with gaseous fuels within a limited Wobbe index range (typically HHV = 45–55 MJ/Nm3 or 1200–1480 Btu/scf). When low calorific fuel gases are fired, the engine will be forced to operate outside its design envelope. The added mass flow will typically raise the cycle pressure ratio and in two-shaft designs also raise the gas generator shaft speed. Typical constraints to be considered due to the altered fuel composition are pressure loads, shaft torques, shaft overspeeds, centrifugal overloading of disks and blades, combustor flameout, surge and flutter limits for the turbomachinery. This poses limitations to usable fuel choices. In this study, the response of a natural gas fired simple cycle two-shaft gas turbine is investigated. A lean premixed combustor is also included in the model. Emphasis has been put on predicting the turbomachinery and combustor behavior as different amounts of N2 or CO2 are added to the fuel path. These two inerts are typically found in large quantities in medium and low calorific fuels. The fuels lower heating value is thus gradually changed from 50 MJ/kg (21.5 kBtu/lb) to 5MJ/kg (2.15 kBtu/lb). A model, based on the Volvo Aero Corp. VT4400 gas turbine (originally Dresser Rand DR990) characterized by one compressor and two expander maps is considered. The free turbine is operated at fixed physical speed. The operating point is plotted in the compressor map and the turbine maps at three distinct firing temperatures representing turndown from full load to bleed opening point. Gas generator speed and shaft power are shown. Surge margin and power turbine power is plotted. Overall efficiency is computed. The behavior of the Volvo lean premixed combustor is also discussed. Air split, primary zone equivalence ratio and temperature is plotted. Combustor loading, combustion intensity and pressure drop is graphed. Results are, as far as possible, given as non-dimensional parameter groups for easy comparison with other machines.

Impact of Fuel Flexibility Needs on a Selected GT Performance in IGCC Application

2012 ◽  
Author(s):  
Mohammad Mansouri Majoumerd ◽  
Peter Breuhaus ◽  
Jure Smrekar ◽  
Mohsen Assadi ◽  
Carmine Basilicata ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Parameter Study ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Lumped Model ◽  
Surge Margin ◽  
Fuel Flexibility ◽  
Compressor Inlet ◽  
The Impact

As part of a European Union (EU) funded H2-IGCC project, a baseline IGCC power plant was established; this was presented at the ASME Turbo Expo 2011 (GT2011-45701). The current paper focuses on a detailed investigation of the impact of using various fuels considering different operating conditions on the gas turbine performance, and the identification of technical solutions for the realization of the targeted fuel flexibility. Using a lumped model, based on real engine data, compressor and turbine maps of the targeted engine were generated and implemented into the detailed GT model made in the commercial heat and mass balance program, IPSEpro. The implementation was done in terms of look-up tables. The impact of fuel change on the gas turbine island has been investigated and reported in this paper. Calculation results show that for the given boundary conditions, the surge margin of the compressor was slightly reduced when natural gas was replaced by hydrogen-rich syngas. The use of cleaned syngas instead of hydrogen-rich syngas resulted in a considerable reduction of the surge margin and elevation of the turbine outlet temperature (TOT) at design point conditions, when keeping the turbine inlet temperature (TIT) and compressor inlet mass flow unchanged. To maintain the TOT and improve the surge margin, when operating the engine with cleaned syngas, a combination of adjustment of variable inlet guide vanes (VIGV) and reduced TIT was considered. A parameter study was carried out to provide better understanding of the current limitations of the engine and to identify possible modifications to improve fuel flexibility.

Continued Enhancement of SGT-600 Gas Turbine Design and Maintenance

2008 ◽  
Author(s):  
Vladimir Navrotsky ◽  
Mats Blomstedt ◽  
Niklas Lundin ◽  
Claes Uebel
Keyword(s):  
Life Cycle ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
High Reliability ◽  
Medium Size ◽  
Power Turbine ◽  
History Of ◽  
And Control ◽  
Reliability And Availability

Current power generation and oil & gas markets are dynamic with continuously growing requirements on gas turbines for high reliability and availability and low emissions and life cycle cost. In order to meet these growing requirements on the gas turbines, the OEM should sustain continued product improvement and employment of innovative solutions and technologies in the area of design, operation and maintenance. This paper describes the successful development and operation experiences of SGT-600 Siemens’ medium size gas turbine and in particular the latest achievements in maintenance and life cycle improvements. High reliability and availability of SGT-600 gas turbine were enabled by further improvements and modifications of the combustor, compressor turbine blade 1 and vane 1, power turbine diffuser and control system. The developed modifications enable operators to utilize the opportunity: • to extend the life cycle of the engine beyond 120,000 EOH (Equivalent Operating Hours), up to 180,000 EOH, depending on the previous operation profile and history of the installation; • to extend the maintenance intervals from 20,000 EOH to 30,000 EOH and that to increase the availability of the engine by up to 1%; • to reduce the emission level to the latest SGT-600 standards.

Static and Dynamic Analysis of 2.5 MW Power Generation Gas Turbine Unit

2008 ◽  
Author(s):  
SooYong Kim ◽  
SeungJoo Choe ◽  
Valeri P. Kovalevskiy ◽  
Dong Hwa Kim
Keyword(s):  
Mathematical Model ◽  
Gas Turbine ◽  
Rotation Speed ◽  
Static Characteristic ◽  
Inlet Temperature ◽  
Gas Generator ◽  
Channel Calculation ◽  
Static And Dynamic Analysis ◽  
Surge Margin ◽  
Power Turbine

Development of a numerical mathematical model to calculate both the static and dynamic characteristics of a multi-shaft gas turbine consisting of a single combustion chamber with advanced cycle components such as intercooler and regenerator is presented in the paper. The numerical mathematical model is based on simplified assumptions such that quasi-static characteristic in turbo-machine and injector is used, pressure loss and heat transfer relation for static calculation neglecting fuel transport time delay can be employed. For study of static and dynamic regime, a control algorithm with following assumptions was made. When the inlet temperature of HPT exceeds the preset value, a signal to stop or open the fuel valve is issued and with a surge margin coefficient Ks<1.1, signal to open the compressor anti surge valve with proportional deflection is issued. At Ks<1.18 or as in starting, a maximum control signal will be issued. Static characteristic of the gas turbine engine in terms of rotation speed ω at ambient temperature of ta = 15°C is carried out. The rotation speed of power turbine is decreased from 20,000 to 4500 rpm, that means 4.4 times, whereas the rotation speed of gas generator is decreased only 2 ∼ 2.5 times. The air flow rate at this time decreased about 3 times. HPC had enough surge margins at all operation ranges. LPC starts to operate with the power turbine speed of 15,000 rpm (approximately 1 MW power output, that means, 40% of the nominal power) and reaches minimal permissible surge margin for safe operation bypassing the air through supercharging channel. Calculation of heat balance showed the difference did not exceed more than 0.06%, validating the accuracy of the applied method. The accuracy of each calculation is confirmed by monitoring mass and energy balance for different time steps of integration.

scholarly journals Variable Power Turbine Nozzle System Mechanical Development

1977 ◽  
Author(s):  
D. L. Carriere ◽  
V. D. Rao ◽  
M. R. Vaughen
Keyword(s):  
Power Plant ◽  
Response Time ◽  
Gas Turbine ◽  
Power Turbine ◽  
Variable Power ◽  
Industrial Gas Turbine ◽  
Gas Turbine Power Plant ◽  
Cycle Temperature

Mechanical, material, thermal, and actuator response time problems encountered and resolved during the development of a variable power turbine nozzle system for a nominal 400-hp (300-kw), 1950 F (1339 K) maximum cycle temperature truck industrial gas turbine power plant are described in this paper.

Transient Analysis of and Control System for Advanced Cycles Based on Micro Gas Turbine Technology

2005 ◽  
Vol 127 (2) ◽  
pp. 340-347 ◽  
Author(s):  
Alberto Traverso ◽  
Federico Calzolari ◽  
Aristide Massardo
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Rotational Speed ◽  
Gas Turbines ◽  
Thermal Stresses ◽  
Maximum Efficiency ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Micro Gas Turbine ◽  
Advanced Cycles

Microturbines have a less complex mechanical design than large-size gas turbines that should make it possible to fit them with a more straightforward control system. However, these systems have very low shaft mechanical inertia and a fast response to external disturbances, such as load trip, that make this very difficult to do. Furthermore, the presence of the recuperator requires smooth variations to the Turbine Outlet Temperature (TOT), when possible, to ensure reduced thermal stresses to the metallic matrix. This paper, after a brief overview of microturbine control systems and typical transients, presents the expected transient behavior of two advanced cycles: the Externally Fired micro Gas Turbine (EFmGT) cycle, where the aim is to develop a proper control system set-up to manage safe part-load operations at constant rotational speed, and a solar Closed Brayton Cycle (CBC), whose control system has to ensure the maximum efficiency at constant rotational speed and constant Turbine Inlet Temperature (TIT).

U. S. Navy Ship Service Gas Turbine Generator Thermocouple Logic Enhancements to Improve Reliability

2014 ◽  
Author(s):  
John Viercinski ◽  
Matthew Hoffman ◽  
Ivan Pineiro ◽  
Dennis Russom ◽  
Helen Kozuhowski ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Temperature Monitoring ◽  
The Other ◽  
Monitoring And Control ◽  
Control Logic ◽  
Turbine Generator ◽  
The Individual ◽  
And Control ◽  
Improve Reliability

The U. S. Navy uses Rolls-Royce gas turbines for ship service power on the DDG-51 class destroyer and the CG-47 class cruiser. Both engines have duplex thermocouples (T/Cs) and redundant T/C harnesses for turbine temperature monitoring and control. One harness provides an average of all the installed T/Cs, while the other provides the full authority digital control (FADC) with an individual signal from each. The legacy FADC algorithm allows up to four T/Cs to be out of average on the individual harness. Any additional T/C failures will cause the control to ignore the entire individual harness and rely on the averaging harness alone. This logic has inadvertently led to multiple over-temp conditions and subsequent engine removals. A change to control logic has been developed that aims to prevent these over-temp scenarios and is currently being introduced to the fleet. This paper will discuss in depth the cause of the over-temp, the examination of the control logic and the correction that is designed to prevent it from recurring.

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