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.

Advances in the Development of a Microturbine Engine

2014 ◽  
Vol 136 (7) ◽  
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 largely exceeds the performance of secondary batteries. To develop such a micro gas turbine engine, experimental and computational work focused on: (1) a 10-mm diameter centrifugal compressor, with the objective to obtain a pressure ratio of about 2.5; (2) a radial inflow turbine; (3) journal and thrust gas bearings (lobe bearings and spiral grooves) and their manufacturing; (4) a small combustor working with hydrogen or hydrocarbon gaseous fuel (propane); (5) a high rotation speed microgenerator; and (6) 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 was performed up to 500,000 rpm and showed that the nominal compression rate at the 840,000 rpm nominal speed should nearly be reached.

Technological Trend of Aircraft Gas Turbines and its Effect on the Development for Ship Propulsion Plants

1970 ◽  
Author(s):  
N. K. H. Scholz
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Gas Turbine Engine ◽  
Design Parameters ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Compression Pressure ◽  
Turbine Engine ◽  
Ship Propulsion

The effect of the main design parameters of the aero gas turbine engine cycle, namely combustion temperature and compression pressure ratio, on the specific performance values is discussed. The resulting development trend has been of essential influence on the technology. Relevant approaches are outlined. The efforts relating to weight and manufacturing expense are also indicated. In the design of aero gas turbine engines increasing consideration is given to the specific flight mission requirements, such as for instance by the introduction of the by-pass principle. Therefore direct application of aero gas turbine engines for ship propulsion without considerable modifications, as has been practiced in the past, is not considered very promising for the future. Nevertheless, there are possibilities to take advantage of aero gas turbine engine developments for ship propulsion systems. Appropriate approaches are discussed. With the experience obtained from aero gas turbine engines that will enter service in the early seventies it should be possible to develop marine gas turbine engines achieving consumptions and lifes that are competitive with those of advanced diesel units.

Coolant Optimization of a Gas Turbine Engine

1993 ◽  
Vol 207 (1) ◽  
pp. 31-47 ◽  
Author(s):  
A Brown ◽  
B A Jubran ◽  
B W Martin
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Gas Turbine Engine ◽  
Heat Extraction ◽  
Optimum Amount ◽  
Turbine Engine ◽  
Compressor Pressure Ratio ◽  
Extraction Parameter ◽  
Overall Efficiency

This paper describes an analysis used to study the performance of the gas turbine engine with particular emphasis on the optimum amount of coolant required for maximum overall efficiency of the engine. The effect of pre-bled air, as well as that drawn from the exit of the compressor, is also studied. The optimum amount of coolant for the engine is found to depend on the effectiveness of the heat extraction parameter A, component efficiencies of the engine and the compressor pressure ratio of the engine.

scholarly journals Development of the AGT101 Regenerator Seals

1987 ◽  
Author(s):  
C. A. Fucinari ◽  
J. K. Vallance ◽  
C. J. Rahnke
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Dynamic Test ◽  
Development Program ◽  
Analytical Techniques ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Turbine Engine ◽  
Seal Design

The design and development of the regenerator seals used in the AGT101 gas turbine engine are described in this paper. The all ceramic AGT101 gas turbine engine was designed for 100 hp at 5:1 pressure ratio with 2500F (1371C) turbine inlet temperature. Six distinct phases of seal design were investigated experimentally and analytically to develop the final design. Static and dynamic test rig results obtained during the seal development program are presented. In addition, analytical techniques are described. The program objectives of reduced seal leakage, without additional diaphragm cooling, to 3.6% of total engine airflow and higher seal operating temperature resulting from the 2000F (1093C) inlet exhaust gas temperature were met.

Performance Analysis of a 50KW Turbogenerator Gas Turbine Engine

1998 ◽  
Author(s):  
S. Y. Kim ◽  
M. R. Park ◽  
S. Y. Cho
Keyword(s):  
Performance Analysis ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Hybrid Vehicle ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Turbine Engine ◽  
Design Point ◽  
Turbine Inlet

This paper describes on/off design performance of a 50KW turbogenerator gas turbine engine for hybrid vehicle application. For optimum design point selection, a relevant pa4rameter study is carried out. The turbogenerator gas turbine engine for a hybrid vehicle is expected to be designed for maximum fuel economy, ultra low emissions, and very low cost. A compressor, combustor, turbine, and a permanent-magnet generator will be mounted on a single high speed (80,000 rpm) shaft that will be supported on air bearings. As the generator is built into the shaft, gearbox and other moving parts become unnecessary and thus will increase the system’s reliability and reduce the manufacturing cost. The engine has a radial compressor and turbine with design point pressure ratio of 4.0. This pressure ratio was set based on calculation of specific fuel consumption and specific power variation with pressure ratio. For the turbine inlet temperature, a rather conservative value of 1100K was selected. Designed mass flow rate was 0.5 kg/sec. Parametric study of the cycle indicates that specific work and efficiency increase at a given pressure ratio and turbine inlet temperature. Off design analysis shows that the gas turbine system reaches self operating condition at about N/NDP = 0.48. Bleeding air for a turbine stator cooling is omitted considering the low TIT in the present engine and to enable the simple geometric configuration for manufacturing purpose. Various engine performance simulations including ambient temperature influence, surging at part load condition; transient analysis were performed to secure the optimum engine operating characteristics. Surge margin throughout the performance analysis were maintained to be over 50% approximately. Present analysis will be compared with performance test result which is scheduled at the end of 1998.

Wave-Rotor Pressure-Gain Combustion Analysis for Power Generation and Gas Turbine Applications

2012 ◽  
Author(s):  
Manikanda Rajagopal ◽  
Abdullah Karimi ◽  
Razi Nalim
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Turbulent Flame ◽  
Pressure Rise ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Specific Power ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Turbine Engine

A wave-rotor pressure-gain combustor (WRPGC) ideally provides constant-volume combustion and enables a gas turbine engine to operate on the Humphrey-Atkinson cycle. It exploits pressure (both compression and expansion) waves and confined propagating combustion to achieve pressure rise inside the combustor. This study first presents thermodynamic cycle analysis to illustrate the improvements of a gas turbine engine possible with a wave rotor combustor. Thereafter, non-steady reacting simulations are used to examine features and characteristics of a combustor rig that reproduces key features of a WRPGC. In the thermodynamic analysis, performance parameters such as thermal efficiency and specific power are estimated for different operating conditions (compressor pressure ratio and turbine inlet temperature). The performance of the WRPGC is compared with the conventional unrecuperated and recuperated engines that operates on the Brayton cycle. Fuel consumption may be reduced substantially with WRPGC introduction, while concomitantly boosting power. Simulations have been performed of the ignition of propane by a hot gas jet and subsequent turbulent flame propagation and shock-flame interaction.

Global Warming Potential Estimations of a Gas Turbine Engine and Effect of Selected Design Parameters

2020 ◽  
Author(s):  
Ali Dinc ◽  
Yousef Gharbia
Keyword(s):  
Global Warming ◽  
Gas Turbine ◽  
Global Warming Potential ◽  
Gas Turbines ◽  
Gas Turbine Engine ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Gas Emissions ◽  
Turbine Engine ◽  
Input Parameters

Abstract Anthropogenic global warming is a result of greenhouse gas emissions from many human activities such as industry, power generation, transportation etc. Burning fossil fuels generates gas emissions and those emissions should be minimized by careful designs and operations for a sustainable world. The gas turbines are typically used in many applications to generate power and propulsion which require burning of liquid fuel, natural gas etc. In this study, Global Warming Potential (GWP) calculations of a 43 MW class gas turbine engine have been performed. Global warming potential values were calculated for a range of selected design parameters such as turbine inlet temperature, compressor pressure ratio, compressor efficiency, turbine efficiency etc. Those design input parameters were changed ± 5% from an assumed baseline to investigate their effects on the total GWP values due to emissions of CO2, H2O and NOx. The results presented a good guide on the selection of design input parameters in order to cut the emissions down from the design perspective of gas turbine engines. A range of reductions in GWP between 0.46% and 5.86% were estimated by the calculations in this study.

scholarly journals The Part-Load Performance of a Gas Turbine Engine With Two Turbines Working in Parallel

1986 ◽  
Author(s):  
Yousef S. H. Najjar ◽  
Taha K. Aldoss
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Pressure Ratio ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Combustion Chambers ◽  
Turbine Engine ◽  
Combustion Gases ◽  
Power Turbine ◽  
In Series

To reduce the inefficiency and the drawbacks incurred by reheat in a gas turbine engine with the two turbines in series, a parallel arrangement is investigated. The combustion gases expand to atmospheric pressure in each turbine. One of the turbines drives the compressor to which it is mechanically coupled while the other develops the power output of the plant. Two methods of control for the reduction of power are considered: a) Varying the fuel supply to the combustion chambers so that the inlet temperature to the turbine driving the compressor is constant, while the inlet temperature to the power turbine is reduced. b) Reducing both temperatures while keeping them equal. The effects of turbines inlet temperatures, pressure ratio and pressure loss in combustion chambers on the cycle efficiency and power output are studied and a sensitivity analysis is carried out, with the aid of a specially constructed computer program. The first method of control proved to be superior.

Demonstration of a Semi-Closed Cycle, Turboshaft Gas Turbine Engine

2000 ◽  
Author(s):  
Peter L. Meitner ◽  
Anthony L. Laganelli ◽  
Paul F. Senick ◽  
William E. Lear
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Gas Turbine Engine ◽  
Exhaust Gas ◽  
Test Results ◽  
Closed Cycle ◽  
Turbine Engine ◽  
The Impact

A semi-closed cycle, turboshaft gas turbine engine was assembled and tested under a cooperative program funded by the NASA Glenn Research Center with support from the U.S. Army. The engine, called HPRTE (High Pressure, Recuperated Turbine Engine), features two distinct cycles operating in parallel; an “inner,” high pressure, recuperated cycle, in which exhaust gas is recirculated, and an “open” through-flow cycle. Recuperation is performed in the “inner,” high pressure loop, which greatly reduces the size of the heat exchanger. An intercooler is used to cool both the recirculated exhaust gas and the fresh inlet air. Because a large portion of the exhaust gas is recirculated, significantly less inlet air is required to produce a desired horsepower level. This reduces the engine inlet and exhaust flows to less than half that required for conventional, open cycle, recuperated gas turbines of equal power. In addition, the reburning of the exhaust gas reduces exhaust pollutants. A two-shaft engine was assembled from existing components to demonstrate concept feasibility. The engine did not represent an optimized system, since most components were oversized, and the overall pressure ratio was much lower than optimum. New cycle analysis codes were developed that are capable of accounting for recirculating exhaust flow. Code predictions agreed with test results. Analyses for a fully developed engine predict almost constant specific fuel consumption over a broad power range. Test results showed significant emissions reductions. This document is the first in a series of papers that arc planned to be presented on semi-closed cycle characteristics, issues, and applications, addressing the impact of recirculating exhaust flow on combustion and engine components.

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