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).

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

2003 ◽  
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).

Micro Gas Turbine With Ceramic Nozzle and Rotor

2005 ◽  
Author(s):  
Takayuki Matsunuma ◽  
Hiro Yoshida ◽  
Norihiko Iki ◽  
Takumi Ebara ◽  
Satoshi Sodeoka ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Rotor ◽  
Total Power ◽  
Inlet Temperature ◽  
Present System ◽  
Outlet Temperature ◽  
Micro Gas Turbine ◽  
Buffer Material ◽  
Inconel 713C

A series of operation tests of a ceramic micro gas turbine has been successfully carried out. The baseline machine is a small single-shaft turbojet engine (J-850, Sophia Precision Corp.) with a centrifugal compressor, an annular type combustor, and a radial turbine. As a first step, an Inconel 713C alloy turbine rotor of 55 mm in diameter was replaced with a ceramic rotor (SN-235, Kyocera Corporation). A running test was conducted at rotational speeds of up to 140,000 rpm in atmospheric air. At this rotor speed, the compression pressure ratio and the thrust were 3 and 100 N, respectively. The total energy level (enthalpy and kinetic energy) of the exhaust gas jet was 240 kW. If, for example, it is assumed that 10% of the total power of the exhaust jet gas was converted into electricity, the present system would correspond to a generator with 24 kW output power. The measured turbine outlet temperature was 950°C (1,740°F) and the turbine inlet temperature was estimated to be 1,280°C (2,340°F). Although the ceramic rotor showed no evidence of degradation, the Inconel nozzle immediately in front of the turbine rotor partially melted in this rotor condition. As a second step, the Inconel turbine nozzle and casing were replaced with ceramic parts (SN-01, Ohtsuka Ceramics Inc.). The ceramic nozzle and case were supported by metal parts. Through tests with the ceramic nozzle, it became evident that one of the key technologies for the development of ceramic gas turbines is the design of the interface between the ceramic components and the metallic components, because the difference between the coefficients of linear thermal expansion of the ceramic and metal produces large thermal stress at their interface in the high-temperature condition. A buffer material made of alumina fiber was therefore introduced at the interface between the ceramic and metal.

scholarly journals Cycle-Tempo Simulation of Ultra-Micro Gas Turbine Fueled by Producer Gas Resulting from Leaf Waste Gasification

2021 ◽  
Vol 24 (3) ◽  
pp. 14-20
Author(s):  
Fajri Vidian ◽  
◽  
Putra Anugrah Peranginangin ◽  
Muhamad Yulianto ◽  
◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Producer Gas ◽  
Turbine Inlet Temperature ◽  
Micro Gas Turbine ◽  
Fuel Ratio ◽  
Waste Gasification

Leaf waste has the potential to be converted into energy because of its high availability both in the world and Indonesia. Gasification is a conversion technology that can be used to convert leaves into producer gas. This gas can be used for various applications, one of which is using it as fuel for gas turbines, including ultra-micro gas ones, which are among the most popular micro generators of electric power at the time. To minimize the risk of failure in the experiment and cost, simulation is used. To simulate the performance of gas turbines, the thermodynamic analysis tool called Cycle-Tempo is used. In this study, Cycle-Tempo was used for the zero-dimensional thermodynamic simulation of an ultra-micro gas turbine operated using producer gas as fuel. Our research contributions are the simulation of an ultra-micro gas turbine at a lower power output of about 1 kWe and the use of producer gas from leaf waste gasification as fuel in a gas turbine. The aim of the simulation is to determine the influence of air-fuel ratio on compressor power, turbine power, generator power, thermal efficiency, turbine inlet temperature and turbine outlet temperature. The simulation was carried out on condition that the fuel flow rate of 0.005 kg/s is constant, the maximum air flow rate is 0.02705 kg/s, and the air-fuel ratio is in the range of 1.55 to 5.41. The leaf waste gasification was simulated before, by using an equilibrium constant to get the composition of producer gas. The producer gas that was used as fuel had the following molar fractions: about 22.62% of CO, 18.98% of H2, 3.28% of CH4, 10.67% of CO2 and 44.4% of N2. The simulation results show that an increase in air-fuel ratio resulted in turbine power increase from 1.23 kW to 1.94 kW. The generator power, thermal efficiency, turbine inlet temperature and turbine outlet temperature decreased respectively from 0.89 kWe to 0.77 kWe; 3.17% to 2.76%; 782 °C to 379 °C and 705°C to 304 °C. The maximums of the generator power and thermal efficiency of 0.89 kWe and 3.17%, respectively, were obtained at the 1.55 air-fuel ratio. The generator power and thermal efficiency are 0.8 kWe and 2.88%, respectively, with the 4.64 air-fuel ratio or 200% excess air. The result of the simulation matches that of the experiment described in the literature.

scholarly journals Combustion of LCV Coal Derived Fuel Gas for High Temperature, Low Emissions Gas Turbines in the British Coal Topping Cycle

1991 ◽  
Author(s):  
G. J. Kelsall ◽  
M. A. Smith ◽  
H. Todd ◽  
M. J. Burrows
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Calorific Value ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Combustion System ◽  
Fuel Gas ◽  
Gas Turbine Combustion ◽  
Topping Cycle

Advanced coal based power generation systems such as the British Coal Topping Cycle offer the potential for high efficiency electricity generation with minimum environmental impact. An important component of the Topping Cycle programme is the development of a gas turbine combustion system to burn low calorific value (3.5–4.0 MJ/m3 wet gross) coal derived fuel gas, at a turbine inlet temperature of 1260°C, with minimum pollutant emissions. The paper gives an overview of the British Coal approach to the provision of a gas turbine combustion system for the British Coal Topping Cycle, which includes both experimental and modelling aspects. The first phase of this programme is described, including the design and operation of a low-NOx turbine combustor, operating at an outlet temperature of 1360°C and burning a synthetic low calorific value (LCV) fuel gas, containing 0 to 1000 ppmv of ammonia. Test results up to a pressure of 8 bar are presented and the requirements for further combustor development outlined.

A Steam-Augmented Gas Turbine With Reheat Combustor for Surface Ships

1997 ◽  
Author(s):  
Herman B. Urbach ◽  
Donald T. Knauss ◽  
Richard W. Garman ◽  
Ashwani K. Gupta ◽  
Michael R. Sexton
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Air Flow ◽  
Flame Temperature ◽  
Engine Performance ◽  
Low Pressure ◽  
Steam Flow ◽  
Maximum Efficiency ◽  
Inlet Temperature ◽  
Full Throttle

The steam-augmented gas turbine (SAGT) differs from commercial steam-injected gas turbines where steam flow may be considerably less than 15% of air flow. SAGT combustors may operate near stoichiometric combustion conditions with steam flow as high as 50% of air flow, thus achieving specific powers exceeding 555 hp-sec/lb. A previous simulation study of the steam-augmented gas turbine, which did not include compressor and turbine maps, examined the applicability of the concept in the Navy’s DDG-51-class ship environment. In this re-examination, component maps were employed to establish credible off-design engine performance, and to confirm estimates of overall ship fuel requirements based solely on anticipated component efficiencies. Also, the present simulation employs a heat-exchanger sub-program fully integrated into the main software program. The re-examination has led to several revisions and refinements of previous conclusions, which are discussed in the text. The SAGT engine concept described herein, dispenses with intercoolers, but adds a low-pressure reheat combustor. The low-pressure combustor flame temperature exceeds 2700° F, which analyses show to be stable. Exhaust gas temperatures are not permitted to fall below 450° F, and the heat recovery steam generator is designed to hold feedwater temperatures close to 300° F to avoid the gas-side acid dewpoint. At the most efficient operating points, the efficiency of this new reheat SAGT engine exceeds 44.5% with a 2200° F turbine inlet temperature, at an ambient 100°-F temperature. Moreover, it exhibits a 23% reduction in overall system volume. Simulation data show that the maximum efficiency of the SAGT engine peaks at engine powers required for cruising speeds, in contrast to the efficiency of the LM2500, which peaks at full-throttle. Since Navy ships operate near cruise conditions for the majority of their mission time, a SAGT plant uses 29% less fuel than the baseline LM2500 plant. Moreover, employing conservative cost estimates, the SAGT plant is quite competitive on a first-acquisition cost basis with gas turbines currently in the fleet.

Development of a Low NOx Combustor for 300kW-Class Ceramic Gas Turbine (CGT302)

1998 ◽  
Author(s):  
A. Okuto ◽  
T. Kimura ◽  
I. Takehara ◽  
T. Nakashima ◽  
Y. Ichikawa ◽  
...  
Keyword(s):  
Research And Development ◽  
Gas Turbine ◽  
Flow Rate ◽  
Gas Turbines ◽  
Combustion Efficiency ◽  
Development Project ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Nox Emissions

Research and development project of ceramic gas turbines (CGT) was started in 1988 promoted by the Ministry of International Trade and Industry (MITI) in Japan. The target of the CGT project is development of a 300kW-class ceramic gas turbine with a 42 % thermal efficiency and a turbine inlet temperature (TIT) of 1350°C. Three types of CGT engines are developed in this project. One of the CGT engines, which is called CGT302, is a recuperated two-shaft gas turbine for co-generation use. In this paper, we describe the research and development of a combustor for the CGT302. The project requires a combustor to exhaust lower pollutant emissions than the Japanese regulation level. In order to reduce NOx emissions and achieve high combustion efficiency, lean premixed combustion technology is adopted. Combustion rig tests were carried out using this combustor. In these tests we measured the combustor performance such as pollutant emissions, combustion efficiency, combustor inlet/outlet temperature, combustor inlet pressure and pressure loss through combustor. Of course air flow rate and fuel flow rate are controlled and measured, respectively. The targets for the combustor such as NOx emissions and combustion efficiency were accomplished with sufficient margin in these combustion rig tests. In addition, we report the results of the tests which were carried out to examine effects of inlet air pressure on NOx emissions here.

Conceptual Investigation of a Small Reheat Gas Turbine System

2003 ◽  
Author(s):  
Norihiko Iki ◽  
Hirohide Furutani ◽  
Sanyo Takahashi
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Water Injection ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Micro Gas Turbine ◽  
Thermal Generator ◽  
Process Simulator ◽  
Characteristic Component

The mirror gas turbine proposed by Tsujikawa and Fujii extends the applications of turbo machinery. The characteristic component of a mirror gas turbine is a thermal generator, which is a kind of “inverted Brayton cycle”. The operating sequence of the thermal generator is reverse that of an ordinary gas turbine, namely, the hot working fluid is first expanded, and then cooled, compressed, and finally exhausted. In this work, we investigated the theoretical feasibility of inserting a thermal generator to a small reheat gas turbine of 30–100kW classes. Using process simulator software, we calculated and compared the thermal efficiency of this reheat gas turbine to that of a micro gas turbine under several conditions, turbine inlet temperature. This comparison showed that the performances of the both gas turbines are significantly influenced by the performance of the heat exchanger used for the recuperator. The efficiency of the micro gas turbine is also improved by using water injection into the compressor to cool the inlet gas. The resulting thermal efficiency of this reheat gas turbine is about 7% higher than that of a micro gas turbine with the same power unit.

Adaptive Control of Micro Gas Turbine for Engine Degradation Compensation

2019 ◽  
Author(s):  
Valentina Zaccaria ◽  
Mario L. Ferrari ◽  
Konstantinos Kyprianidis
Keyword(s):  
Adaptive Control ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Reliability ◽  
Energy Conversion Efficiency ◽  
Health Condition ◽  
Effective Control ◽  
Inlet Temperature ◽  
Or Efficiency ◽  
Micro Gas Turbine

Abstract Micro gas turbine engines in the range of 1–100 kW are playing a key role in distributed generation applications, due to the high reliability and quick load following that favor their integration with intermittent renewable sources. Micro-CHP systems based on gas turbine technology are obtaining a higher share in the market and are aiming at reducing the costs and increasing energy conversion efficiency. An effective control of system operating parameters during the whole engine lifetime is essential to maintain desired performance and at the same time guarantee safe operations. Because of the necessity to reduce the costs, fewer sensors are usually available than in standard industrial gas turbines, limiting the choice of control parameters. This aspect is aggravated by engine aging and deterioration phenomena that change operating performance from the expected one. In this situation, a control architecture designed for healthy operations may not be adequate anymore, because the relationship between measured parameters and unmeasured variables (e.g. turbine inlet temperature or efficiency) varies depending on the level of engine deterioration. In this work, an adaptive control scheme is proposed to compensate the effects of engine degradation over the lifetime. Component degradation level is monitored by a diagnostic tool that estimates performance variations from available measurements; then, the information on the gas turbine health condition is used by an observer-based model predictive controller to maintain the machine in a safe range of operation and limit the reduction in system efficiency.

Experimental Results and Transient Model Validation of an Externally Fired Micro Gas Turbine

2005 ◽  
Author(s):  
Alberto Traverso ◽  
Riccardo Scarpellini ◽  
Aristide Massardo
Keyword(s):  
Control System ◽  
Gas Turbine ◽  
Control Point ◽  
Point Of View ◽  
Experimental Results ◽  
Inlet Temperature ◽  
Transient Model ◽  
Micro Gas Turbine ◽  
Plant Behavior ◽  
Plant Configuration

This paper presents the performance of the world’s first Externally Fired micro Gas Turbine (EFmGT) demonstration plant based on micro gas turbine technology. The plant was designed by Ansaldo Ricerche (ARI) s.r.l. and the Thermochemical Power Group (TPG) of the Universita` di Genova, using the in-house TPG codes TEMP (Thermoeconomic Modular Program) and TRANSEO. The plant was based on a recuperated 80 kW micro gas turbine (Elliott TA-80R), which was integrated with the externally fired cycle at the ARI laboratory. The first goal of the plant construction was the demonstration of the EFmGT system at full and part-load operations, mainly from the control point of view. The performance obtained in the field can be improved in the near future using high-temperature heat exchangers and apt external combustors, which should allow the system to operate at the actual micro gas turbine inlet temperature (900–950 °C). This paper presents the plant layout and the control system employed for regulating the microturbine power and rotational speed. The experimental results obtained by the pilot plant in early 2004 are shown: the feasibility of such a plant configuration has been demonstrated, and the control system has successfully regulated the shaft speed in all the tests performed. Finally, the plant model in TRANSEO, which was formerly used to design the control system, is shown to accurately simulate the plant behavior both at steady-state and transient conditions.

scholarly journals AMBIENT TEMPERATURE IMPACT ON MICRO GAS TURBINES: EXPERIMENTAL CHARACTERIZATION

2018 ◽  
Vol 20 ◽  
pp. 78-85 ◽  
Author(s):  
Iacopo Rossi ◽  
Alberto Traverso
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Combined Cycle ◽  
Active Management ◽  
Small Scale ◽  
Inlet Temperature ◽  
Large Power ◽  
Micro Gas Turbine

In the panorama of gas turbines for energy production, a great relevance is given to performance impact of the ambient conditions. Under the influence of ambient temperature, humidity and other factors, the engine performance is subject to consistent variations. This is true for large power plants as well as small engines. In Combined Cycle configuration, variation in performance are mitigated by the HRSG and the bottoming steam cycle. In a small scale system, such as a micro gas turbine, the influence on the electric and thermal power productions is strong as well, and is not mitigated by a bottoming cycle. This work focuses on the Turbec T100 micro gas turbine and its performance through a series of operations with different ambient temperatures. The goal is to characterize the engine performance deriving simple correlations for the influence of ambient temperature on performance, at different electrical loads. The newly obtained experimental data are compared with previous performance curves on a modified machine, to capture the differences due to hardware degradation in time. An active management of the compressor inlet temperature may be developed in the future, basing on the analysis reported here.

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