Gas Turbine Package Research Articles

Assessment of the effectiveness of ventilation for gas turbine generator set safety

Increasing global warming problems appeal to the employment of clean power generation machineries such as gas turbines. Gas turbine is gas-fired engine which is usually enclosed in an acoustic enclosure for higher reliability and lower operating noise. However, it may face the risk of fuel gas accumulation inside the package which can be extremely dangerous. For the safety of a gas turbine generator set, proper ventilation system is crucial to prevent it from danger by diluting the potential leaked gas. Inspired by the significance of ventilation, this paper aims to present and propose study for the assessment of the effectiveness of ventilation for gas turbine packages in worst-case gas leak. A 2 MW ZK2000 gas turbine was chosen for the study. Method of assessment was introduced and numerical studies by Computational Fluid Dynamics (CFD) were adopted, including both transient and steady state analysis. Aiming to figure out the conditions for worst-case gas leak, the location of leak that may cause the most dangerous gas accumulation was obtained by identifying the poorly ventilated regions within the enclosure. After that, the leak rate was estimated that just to trigger the gas detector at the ventilation outlet according to ISO 21789. Worst-case gas leak simulations were performed in cold engine situation because of the possibility analysis of gas leak. The results at standard conditions show great compliance with the limited value in the code thus indicates that the capability of the current ventilation design. Effect of dilution was studied with various ambient temperatures and ventilation flow rates. One of the key findings is that the flow uniformity has the major impact on enhancing dilution of gas cloud. Structures improvements within enclosure and operation instructions were suggested for the safety of gas turbine unit in the event of gas leak.

Prediction of Pressure Rise in a Gas Turbine Exhaust Duct Under Flameout Scenarios While Operating on Hydrogen and Natural Gas Blends

Abstract In recent years, there is a growing interest in blending hydrogen with natural gas fuels to produce low-carbon electricity. It is important to evaluate the safety of gas turbine packages under these conditions, such as late-light off and flameout scenarios. However, the assessment of the safety risks by performing experiments in full-scale exhaust ducts is a very expensive and, potentially, risky endeavor. Computational simulations using a high fidelity CFD model provide a cost-effective way of assessing the safety risk. In this study, a computational model is implemented to perform three-dimensional, compressible, and unsteady simulations of reacting flows in a gas turbine exhaust duct. Computational results were validated against data obtained at the simulated conditions in a representative geometry. Due to the enormous size of the geometry, special attention was given to the discretization of the computational domain and the combustion model. Results show that CFD model predicts the main features of the pressure rise driven by the combustion process. The peak pressures obtained computationally and experimentally differed by 20%. This difference increased up to 45% by reducing the preheated inflow conditions. The effects of rig geometry and flow conditions on the accuracy of the CFD model are discussed.

Development and Integration of the Dual Fuel Combustion System for the MGT Gas Turbine Family

Abstract Industrial gas turbines like the MGT6000 are often operated as power supply or as mechanical drives. In these applications, liquid fuels like “diesel fuel no. 2” can be used either as main fuel or as backup fuel if natural gas is not reliably available. The MAN gas turbines (MGT) operate with the advanced can combustion (ACC) system, which is capable of ultralow NOx emissions for gaseous fuels. This system has been further developed to provide dry dual fuel capability. In this paper, we describe the design and detailed experimental validation process of the liquid fuel injection, and its integration into the gas turbine package. A central lance with an integrated two-stage nozzle is employed as a liquid pilot stage, enabling ignition and startup of the engine on liquid fuel only. The pilot stage is continuously operated, whereas the bulk of the liquid fuel is injected through the premixed combustor stage. The premixed stage comprises a set of four decentralized nozzles based on fluidic oscillator atomizers, wherein atomization of the liquid fuel is achieved through self-induced oscillations. We present results illustrating the spray, hydrodynamic, and emission performance of the injectors. Extensive testing of the burner at atmospheric and full load high-pressure conditions has been performed, before verification within full engine tests. We show the design of the fuel supply and distribution system. Finally, we discuss the integration of the dual fuel system into the standard gas turbine package of the MGT6000.

The CSP (Concentrated Solar Power) Plant with Brayton Cycle: A Third Generation CSP System

The main goal of this study is that electricity unit price is lower than 6 cents (US) producing in a CSP (Concentrated Solar Power) plant. For this goal, the paper suggests an integrated facility with thermal energy storage. The plant includes heliostat area, air cavity receiver, gas turbine package (compressor, combustion chamber and generator), steam turbine and generator, heat exchanger, sensible thermal energy storage system and condenser. The process details are heated air through SIC (Silicon Carbide) air cavity tube receiver will be sent to the gas turbine (Brayton Cycle) and hot air from output of gas turbine will be source to heat exchanger to steam production. Steam from output of the heat exchanger will be supplied to the TES (Thermal Energy Storage) for its charging and second turbine (Rankine Cycle) for to generate electricity. Thus, the total efficiency of the plant reaches 55% during sunshine. Assumptions that is to calculate unit price are several schedules and interest rates for every year and amortization and taxation are ignored. With these assumptions, the paper's aim is achieving the goal with 5.7 US ¢/kWhe for 13 years return time, %3 interest rate without subsidizing.

Implementation of a top-down noise control strategy for a liquefied natural gas peak-shaving facility

ABSTRACTThere have been many previous noise-related studies on liquefied natural gas (LNG) facilities in the United States; however, noise control of these facilities using a top-down approach has not been explored in detail. Most studies have demonstrated noise compliance to applicable standards by focusing on a combination of treatments and specifications, with less consideration on control technology feasibility, ranking, and cost-effectiveness. The Federal Energy Regulatory Commission (FERC) prohibits natural gas facilities from emitting day-night noise levels in excess of 55 dB(A) (equivalent to 24-hr continuous level of 49 dB(A)) at nearby receivers. A case study was conducted to evaluate a top-down approach to reduce noise at a typical LNG peak-shaving facility under normal operating conditions, accounting for technical feasibility, control effectiveness, and cost implications. A modeling approach (International Organization for Standardization standard ISO 9613-2) was used to predict and evaluate the facility’s noise reduction potential. The study found that the strategy could achieve feasible and environmentally effective reductions up to 11 dB(A) at 500 m from the facility by first identifying source groups with highest-emitting sources and then targeting major noise source contributors per group. This approach is cost-effective because the FERC noise goals can still be achieved by avoiding unnecessary control costs associated with lower-ranked sources. The study identified the following four source groups as the highest noise emitters: (1) liquefaction and instrument air, (2) boil-off gas (BOG) compression, (3) glycol water system (air coolers), and (4) pretreatment. Of all the treatments evaluated, installation of enhanced silencers for gas turbine (GT) package—as well as construction of an acoustical building for the BOG compressors and drivers—resulted in the greatest noise reduction at nearby receivers. The study notes that incremental treatment costs presented in this paper are approximate estimates that may vary depending on factors such as facility size and region.Implications: This study assessed potential noise reductions associated with implementing a top–down noise control strategy on a typical LNG peak-shaving facility. The study determined the top–down noise control strategy could achieve feasible and environmentally effective reductions up to 11 decibels at receivers within 500 m from the facility’s center. As LNG suppliers need to support potential supply disruptions, some regions of the US, including New England and Gulf Coast with projected increase in LNG exports and growing needs from power sector, may find information in this study useful with regard to evaluating and prioritizing noise reduction potential of their LNG peak-shaving facilities.

Extension of Fuel Flexibility by Combining Intelligent Control Methods for Siemens SGT-400 Dry Low Emission Combustion System

Extension of gas fuel flexibility of a current production SGT-400 industrial gas turbine combustor system is reported in this paper. A SGT-400 engine with hybrid combustion system configuration to meet a customer's specific requirements was string tested. This engine was tested with the gas turbine package driver unit and the gas compressor-driven unit to operate on and switch between three different fuels with temperature-corrected Wobbe index (TCWI) varying between 45 MJ/m3, 38 MJ/m3, and 30 MJ/m3. The alteration of fuel heating value was achieved by injection or withdrawal of N2 into or from the fuel system. The results show that the engine can maintain stable operation on and switching between these three different fuels with fast changeover rate of the heating value greater than 10% per minute without shutdown or change in load condition. High-pressure rig tests were carried out to demonstrate the capabilities of the combustion system at engine operating conditions across a wide range of ambient conditions. Variations of the fuel heating value, with Wobbe index (WI) of 30 MJ/Sm3, 33 MJ/Sm3, 35 MJ/Sm3, and 45 MJ/Sm3 (natural gas, NG) at standard conditions, were achieved by blending NG with CO2 as diluent. Emissions, combustion dynamics, fuel pressure, and flashback monitoring via measurement of burner metal temperatures, were the main parameters used to evaluate the impact of fuel flexibility on combustor performance. Test results show that NOx emissions decrease as the fuel heating value is reduced. Also note that a decreasing fuel heating value leads to a requirement to increase the fuel supply pressure. Effect of fuel heating value on combustion was investigated, and the reduction in adiabatic flame temperature and laminar flame speed was observed for lower heating value fuels. The successful development program has increased the capability of the SGT-400 standard production dry low emissions (DLE) burner configuration to operate with a range of fuels covering a WI corrected to the normal conditions from 30 MJ/N·m3 to 49 MJ/N·m3. The tests results obtained on the Siemens SGT-400 combustion system provide significant experience for industrial gas turbine burner design for fuel flexibility.

Generalised analysis of compensating balancing sleeves with experimental results from a scaled industrial turbine coupling shaft

The paper furthers the analysis of a recently proposed balancing methodology for high-speed, flexible shafts. This mechanism imparts corrective balancing moments, having the effect of simulating the fixing moments of equivalent double or single encastre mounted shafts. This is shown to theoretically eliminate/nullify the first lateral critical speed, and thereby facilitate safe operation with reduced lateral critical speed margins. The paper extends previously reported research to encompass a more generalised case of multiple, concentrated, residual imbalances, thereby facilitating analysis of any imbalance distribution along the shaft. Solutions provide greater insight of the behaviour of the balancing sleeve concept, and the beneficial implications for engineering design. Specifically, (1) a series of concentrated imbalances can be regarded as an equivalent level of uniform eccentricity, and balance sleeve compensation is equally applicable to a generalised unbalanced distribution, (2) compensation depends on the sum of the applied balancing sleeve moments and can therefore be achieved using a single balancing sleeve (thereby simulating a single encastre shaft), (3) compensation of the second critical speed, and to a lesser extent higher orders, is possible by use of two balancing sleeves, positioned at shaft ends, (4) the concept facilitates on-site commissioning of trim balance, which requires a means of adjustment at only one end of the shaft, (5) the Reaction Ratio, RR, (simply supported/encastre), is independent of residual eccentricity, so that the implied benefits resulting from the ratio (possible reductions in the equivalent level of eccentricity) are additional to any balancing procedures undertaken prior to encastre simulation. Analysis shows that equivalent reductions in the order of 1/25th, are possible. Experimental measurements from a scaled model of a typical drive coupling employed on an industrial gas turbine package, loaded asymmetrically with a concentrated point of imbalance, are used to support the analysis and conclusions.

The results of pre-design studies on the development of a new design of gas turbine compressor package of GPA-C-16 type

The article summarizes the results of analysis of data concerning the operation of turbocompressor packages at compressor stations for the natural gas transmission system of Ukraine. The basic requirements for gas turbine compressor packages used for modernization and reconstruction of compressor stations are considered. Using a 16 MW gas turbine package GPA-C-16S/76-1,44M1 as an example, the results of pre-design studies and some technical solutions that improve the energy efficiency of gas turbine compressor packages and their reliability, as well as its environmental performance are given. In particular, the article deals with the matching of performance characteristics of a centrifugal compressor (hereinafter compressor) and gas turbine drive to reduce fuel gas consumption; as well as application of energy efficient technologies, in particular, exhaust gas heat recovery units and gas-oil heat exchangers in turbocompressor packages oil system; as well as reducing emissions of carbon monoxide into the atmosphere using a catalytic exhaust system. Described technical solutions can be used for development of other types of gas turbine compressor packages.

Evaluation of the Shock Resistance of a Gas Turbine Package

Evaluation of the Shock Resistance of a Gas Turbine Package

Advanced gas turbine packaging

Latest achievements, new procedures and modern methods on the gas turbine packaging and the integration of a gas turbine in a plant are discussed. The goal is an optimum gas turbine package arrangement considering performance, reliability and commercial conditions. The focus is to explain latest technologies and recent methods to obtain the lowest ‘total cost of ownership’ for a gas turbine package. Critical areas related to the gas turbine packaging such as the inlet air filter system, the fuel system, the heat recovery system, the control system, monitoring methods, the lubrication oil system and others are explained. A case study is also presented.

Gas Turbine Modeling for Diagnosis and Control

The supervision of performance in gas turbine applications is crucial in order to achieve: (i) reliable operations, (ii) low heat stress in components, (iii) low fuel consumption, and (iv) efficient overhaul and maintenance. To obtain a good diagnosis of performance it is important to have tests which are based on models with high accuracy. A main contribution is a systematic design procedure to construct a fault detection and isolation (FDI) system for complex nonlinear models. To fulfill the requirement of an automated design procedure, a thermodynamic gas turbine package (GTLib) is developed. Using the GTLib framework, a gas turbine diagnosis model is constructed where component deterioration is introduced. In the design of the test quantities, equations from the developed diagnosis model are carefully selected. These equations are then used to implement a constant gain extended Kalman filter (CGEKF)-based test quantity. The test quantity is used in the FDI-system to supervise the performance and in the controller to estimate the flame temperature. An evaluation is performed using experimental data from a gas turbine site. The case study shows that the designed FDI-system can be used when the decision about a compressor wash is taken. Thus, the proposed model-based design procedure can be considered when an FDI-system of an industrial gas turbine is constructed.

Knowledge Capture, Cross Boundary Communication and Early Validation with Dynamic A3 Architectures

AbstractUnderstanding and extracting systems information is a time consuming, demanding and expensive process. Complicating factors are cross‐boundary communication methods and tools. We combine an informal and formal systems engineering method; Lean manufacturing principles and Model Based systems Engineering (MBSE) resulting in Dynamic A3 architecture. Dynamic A3 Architecture is a hierarchy of overviews from super‐system to sub‐system that the reader can navigate through active links. We applied the method to a lube oil system of a gas turbine package. We found that Dynamic A3 Architecture can ease internal and cross boundary communication, train new employees, facilitate knowledge capture, and share common understanding of the “system of interest”. A functional sequence diagram, which is a hybrid of a state and functional diagram, can assist in early validation of process applications.

200kW급 마이크로 가스터빈 시스템의 설계 변수 민감도 해석

This paper describes the outcome of the design of a 200 kW class micro gas turbine and the sensitivity of its performance(efficiency and power) to the variations in major design parameters. The reference design parameters were set up based on the best available component technologies. The resulting net electricity generation efficiency of the micro gas turbine package was found to be competitive to those of other systems in the market. The sensitivities of power and efficiency to the variations in compressor and turbine efficiencies, pressure ratio, turbine inlet temperature, recuperator effectiveness, secondary air ratio, pressure loss ratios of both the cold and hot sides of the recuperator were estimated. Based on the sensitivity data, a simplified method to predict the variation in system performance responding to the combinations of small changes in all design parameters were set up and validated.

Gas Turbine Optimum Arrangement for Process Plants

The optimum configuration for gas turbine package regarding design, reliability, safety, commercial condition, and performance is addressed. The main concern is finding the solution to obtain optimum fuel consumption, low emission, and reasonable reliability. Gas turbine degradation is outlined to offer optimum condition monitoring practice. Recommendations regarding gas turbine components, arrangement, auxiliaries, performance test, and proper maintenance are also presented to cover both mechanical drive and power generation applications in process units.

Degradation in Gas Turbine Systems

Any prime mover exhibits the effects of wear and tear over time. The problem of predicting the effects of wear and tear on the performance of any engine is still a matter of discussion. Because the function of a gas turbine is the result of the fine-tuned cooperation of many different components, the emphasis of this paper is on the gas turbine and its driven equipment (compressor or pump) as a system, rather than on isolated components. We will discuss the effect of degradation on the package as part of a complex system (e.g., a pipeline, a reinjection station, etc.). Treating the gas turbine package as a system reveals the effects of degradation on the match of the components as well as on the match with the driven equipment. This article will contribute insights into the problem of gas turbine system degradation. Based on some detailed studies on the mechanisms that cause engine degradation, namely, changes in blade surfaces due to erosion or fouling, and the effect on the blade aerodynamics; changes in seal geometries and clearances, and the effect on parasitic flows; and changes in the combustion system (e.g., which result in different pattern factors), the effects of degradation will be discussed. The study includes a methodology to simulate the effects of engine and driven equipment degradation. With a relatively simple set of equations that describe the engine behavior, and a number of linear deviation factors which can easily be obtained from engine maps or test data, the equipment behavior for various degrees of degradation will be studied. A second model, using a stage by stage model for the engine compressor, is used to model the compressor deterioration. The authors have avoided to present figures about the speed of degradation, because it is subject to a variety of operational and design factors that typically cannot be controlled entirely.

Field Demonstration of a 1.5 MW Industrial Gas Turbine With a Low Emissions Catalytic Combustion System

An electric utility grid connected test facility has been established at Silicon Valley Power (SVP) in Santa Clara, California to validate the reliability, availability, maintainability, and durability (RAMD) of a commercial-ready catalytic combustor system (XONON). Installed in the Silicon Valley Test Facility (SVTF) is a 1.5MW Kawasaki MIA-13A gas turbine fitted with a catalytic combustor. The gas turbine package is controlled by a Woodward MicroNet control system. The combustor utilizes a two stage lean premix preburner system to obtain the required catalyst inlet temperatures and low NOx over the operating load range. The fuel-air mixer incorporates counter rotating swirlers to mix the catalyst fuel and air to achieve the desired uniformity. The patented catalyst design is composed of specially coated metal foils. Overall engine performance was measured and the emissions were continuously monitored. As of Dec. 1999, emissions of NOx<2.5 ppmv and CO and UHC<6 ppmv have been maintained at 100 percent load for over 3700 hours of operation on the utility grid. The turbine continues to operated 24 hours a day, 7 days per week with commercial levels of unit availability.

Prediction of Dynamic Voltages During Plant Startup by Computer Techniques

A gas-turbine package power plant was used to provide startup power for a 250-MW steam-generating unit. Performance of the excitation system during startup of large power-station auxiliary motors closely matched that previously calculated by a digital-computer program. Results of the computer study and full- scale verification tests are presented. These results verified that the digital-computer program used accurately simulated the dynamic characteristics of the excitation system, generator, and motor. Based on this verification, it was concluded that further computer studies could be utilized with confidence to predict voltage dips at critical locations in the power system.

パッケージ形ガスタービンの動向

パッケージ形ガスタービンの動向

Sound control for gas turbine package power plants.

Abstract The Gas Turbine Package Power Plant is a self-contained generating unit capable of 11,250 Kw. Designed for emergency, stand-by power it is being installed in residential areas. This article presents results of acoustical measurements before and after treatment for noise control. The breaking down of the complex sound source into individual components and treating each item individually provided a successful solution.