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.

Adaptive Control of Microgas Turbine for Engine Degradation Compensation

2020 ◽  
Vol 142 (4) ◽  
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 ◽  
Industrial Gas Turbines

Abstract Microgas turbine (MGT) 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-combined heat and power (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 (TIT) 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 the 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.

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.

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.

Flameholding Tendencies of Natural Gas and Hydrogen Flames at Gas Turbine Premixer Conditions

2014 ◽  
Author(s):  
Elliot Sullivan-Lewis ◽  
Vincent McDonell
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
High Reliability ◽  
Elevated Pressure ◽  
Inlet Temperature ◽  
Increased Risk ◽  
Wide Range ◽  
Lean Premixed

Ground based gas turbines are responsible for generating a significant amount of electric power as well as providing mechanical power for a variety of applications. This is due to their high efficiency, high power density, high reliability, and ability to operate on a wide range of fuels. Due to increasingly stringent air quality requirements, stationary power gas turbines have moved to lean-premixed operation. Lean-premixed operation maintains low combustion temperatures for a given turbine inlet temperature, resulting in low NOx emissions while minimizing emissions of CO and hydrocarbons. In addition, to increase overall cycle efficiency, engines are being operated at higher pressure ratios and/or higher combustor inlet temperatures. Increasing combustor inlet temperatures and pressures in combination with lean-premixed operation leads to increased reactivity of the fuel/air mixture, leading to increased risk of potentially damaging flashback. Curtailing flashback on engines operated on hydrocarbon fuels requires care in design of the premixer. Curtailing flashback becomes more challenging when fuels with reactive components such as hydrogen are considered. Such fuels are gaining interest because they can be generated from both conventional and renewable sources and can be blended with natural gas as a means for storage of renewably generated hydrogen. The two main approaches for coping with flashback are either to design a combustor that is resistant to flashback, or to design one that will not anchor a flame if a flashback occurs. An experiment was constructed to determine the flameholding tendencies of various fuels on typical features found in premixer passage ways (spokes, steps, etc.) at conditions representative of a gas turbine premixer passage way. In the present work tests were conducted for natural gas and hydrogen between 3 and 9 atm, between 530 K and 650K, and free stream velocities from 40 to 100 m/s. Features considered in the present study include a spoke in the center of the channel and a step at the wall. The results are used in conjunction with existing blowoff correlations to evaluate flameholding propensity of these physical features over the range of conditions studied. The results illustrate that correlations that collapse data obtained at atmospheric pressure do not capture trends observed for spoke and wall step features at elevated pressure conditions. Also, a notable fuel compositional effect is observed.

scholarly journals Diagnostics-Oriented Modelling of Micro Gas Turbines for Fleet Monitoring and Maintenance Optimization

Processes ◽  
2018 ◽  
Vol 6 (11) ◽  
pp. 216 ◽  
Author(s):  
Moksadur Rahman ◽  
Valentina Zaccaria ◽  
Xin Zhao ◽  
Konstantinos Kyprianidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Monitoring ◽  
High Reliability ◽  
Small Scale ◽  
Power Generators ◽  
Micro Gas Turbine ◽  
Commercial Off The Shelf ◽  
And Performance ◽  
The Cost

The market for the small-scale micro gas turbine is expected to grow rapidly in the coming years. Especially, utilization of commercial off-the-shelf components is rapidly reducing the cost of ownership and maintenance, which is paving the way for vast adoption of such units. However, to meet the high-reliability requirements of power generators, there is an acute need of a real-time monitoring system that will be able to detect faults and performance degradation, and thus allow preventive maintenance of these units to decrease downtime. In this paper, a micro gas turbine based combined heat and power system is modelled and used for development of physics-based diagnostic approaches. Different diagnostic schemes for performance monitoring of micro gas turbines are investigated.

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.

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 Review of Recuperator used in Micro Gas Turbine

2021 ◽  
Vol 9 (VIII) ◽  
pp. 634-637
Author(s):  
Yastuti Rao Gautam
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Unit ◽  
High Reliability ◽  
Compressed Air ◽  
Exhaust Gas ◽  
Gas Turbine Unit ◽  
Micro Gas Turbine

Micro gas turbines are an auspicious technology for power generation because of their small size, low pollution, low maintenance, high reliability and natural fuel used. Recuperator is vital requirement in micro gas turbine unit for improve the efficiency of micro turbine unit . Heat transfer and pressure drop characteristics are important for designing an efficient recuperator. Recuperators preheat compressed air by transfer heat from exhaust gas of turbines, thus reducing fuel consumption and improving the thermal efficiency of micro gas turbine unit from 16–20% to 30%. The fundamental principles for optimization design of PSR are light weight, low pressure loss and high heat-transfer between exhaust gas to compressed air. There is many type of recuperator used in micro gas turbine like Annular CWPS recuperator , recuperator with involute-profile element , honey well , swiss-Roll etc . In this review paper is doing study of Heat transfer and pressure drop characteristics of many types recuperator.

Advances in the Development of a Micro-Gas Turbine Engine at Onera

2013 ◽  
Author(s):  
O. Dessornes ◽  
S. Landais ◽  
R. Valle ◽  
A. Fourmaux ◽  
S. Burguburu ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Portable Devices ◽  
Good Efficiency ◽  
Turbine Engine ◽  
Micro Gas Turbine ◽  
Overall Efficiency

To reduce the size and weight of power generation machines for portable devices, several systems to replace the currently used heavy batteries are being investigated worldwide. As micro gas turbines are expected to offer the highest power density, several research groups launched programs to develop ultra micro gas turbines: IHI firm (Japan), PowerMEMS Consortium (Belgium). At Onera, a research program called DecaWatt is under development in order to realize a demonstrator of a micro gas turbine engine in the 50 to 100 Watts electrical power range. A single-stage gas turbine is currently being studied. First of all, a calculation of the overall efficiency of the micro gas turbine engine has been carried out according to the pressure ratio, the turbine inlet temperature and the compressor and turbine efficiencies. With realistic hypotheses, we could obtain an overall efficiency of about 5% to 10% which leads to around 200 W/kg when taking into account the mass of the micro gas turbine engine, its electronics, fuel and packaging. Moreover, the specific energy could be in the range 300 to 600 Wh/kg which exceeds largely the performance of secondary batteries. To develop such a micro gas turbine engine, experimental and computational work focused on: • a 10 mm in diameter centrifugal compressor, with the objective to obtain a pressure ratio of about 2.5 • a radial inflow turbine • journal and thrust gas bearings (lobe bearings and spiral grooves) and their manufacturing • a small combustor working with hydrogen or hydrocarbon gaseous fuel (propane) • a high rotation speed micro-generator • the choice of materials Components of this tiny engine were tested prior to the test with all the parts assembled together. Tests of the generator at 700,000 rpm showed a very good efficiency of this component. In the same way, compressor testing has been performed up to 500,000 rpm and has shown that the nominal compression rate at the 840,000 rpm nominal speed should be nearly reached.

Micro Gas Turbine With Ceramic Rotor

2004 ◽  
Author(s):  
Hiro Yoshida ◽  
Takayuki Matsunuma ◽  
Norihiko Iki ◽  
Yoshio Akimune ◽  
Hiroshi Hoya
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Elevated Temperatures ◽  
Rotation Speed ◽  
Turbine Rotor ◽  
Bench Test ◽  
Inlet Temperature ◽  
Micro Gas Turbine ◽  
Basic Performance ◽  
Inconel 713C

A series of operation tests by using a desktop size gas turbine has been successfully carried out. In the first step of the tests, we have concentrated ourselves on the operation at elevated temperatures. Thus the duration of the bench test at each rotation speed was set to be 1 minute. The baseline machine is J-850 (Sophia Precision, Co., Ltd.) originally made for model airplanes. In this study, we replaced an INCONEL 713C alloy turbine rotor with 5.5 cm diameter into a type SN235 ceramic rotor (Kyocera Corporation). Mixture of 70% white kerosene and 30% gasoline was used as the fuel. The running test was made at the rotational speeds up to 140,000 r.p.m. in the atmospheric air. The basic performance of the small gas turbine was found as follows: At 140,000 r.p.m., 1) the turbine inlet temperature was estimated to be higher than 1,200. This estimation was supported by the observation of the partially melted INCONEL alloy nozzle located before the ceramic rotor. But the ceramic rotor revealed no damages. 2) The compression ratio and the thrust of the ceramic rotor turbine attained at 140,000 r.p.m. were 3 and 100 N, respectively. 3) Total energy level of the exhaust gas jet was 240 kW at the same rotation speed. Experiences learned from the present running tests suggest that the small gas turbine system employed in this study could be a useful tool to quicken the cycle of R & D of micro ceramic gas turbines with reasonable costs.

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