Small Radial Swirler Low NOx Combustors for Micro Gas Turbine Applications

2017 ◽  
Author(s):  
Gordon E. Andrews ◽  
Myeong Kim
Keyword(s):  
Heat Release ◽  
Gas Turbines ◽  
Fuel Injection ◽  
Thermal Power ◽  
Inlet Temperature ◽  
Micro Gas Turbine ◽  
Air Inlet ◽  
Primary Zone ◽  
Flame Development ◽  
Scale Down

There is a growing interest in micro-gas turbines for distributed electric power production. This work examines the scale down of a successful low NOx radial swirler from a combustor of 140mm diameter to one of 76mm diameter, suitable for micro-gas turbines in the 30–100kW electric size range. A 40mm outlet eight bladed radial swirler was investigated for four radial swirler vane depths from 30.5mm to 12.2mm and a constant pressure loss of 2.7% at different reference Mach numbers or residence times. For a 740K inlet temperature and 0.6 equivalence ratio, Ø, these gave combustor thermal loadings at atmospheric pressure from 33 to 62 kW and heat release of 7–14 MW/m2bar. The small radial swirlers had lean stable flames with near lean flammability weak extinction. The vane passage single hole fuel injection achieved NOx emissions of 1–5ppm at 15% oxygen, 740K air inlet temperature and 1700K primary zone temperature, with <10ppm CO. The 1ppm NOx was for the smallest vane depth and lowest thermal power. The higher NOx for the larger heat release swirler designs were due to the longer flame development and a greater formation of prompt NOx, due to the high UHC for most of the flame development.

scholarly journals Reduced NOx Emissions Using Low Radial Swirler Vane Angles

1991 ◽  
Author(s):  
H. S. Alkabie ◽  
G. E. Andrews
Keyword(s):  
Gas Turbines ◽  
Fuel Injection ◽  
Combustion Efficiency ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Primary Zone ◽  
Industrial Gas Turbines ◽  
Curved Blade ◽  
Swirl Vane ◽  
Vane Angle

The influence of vane angle and hence swirl number of a radial swirler on the weak extinction, combustion inefficiency and NOx emissions was investigated at lean gas turbine combustor primary zone conditions. A 140mm diameter atmospheric pressure low NOx combustor primary zone was developed with a Mach number simulation of 30% and 43% of the combustor air flow into the primary zone through a curved blade radial swirler. The range of radial swirler vane angles was 0–60 degrees and central radially outward fuel injection was used throughout with a 600K inlet temperature. For zero vane angle radially inward jets were formed that impinged and generated a strong outer recirculation. This was found to have much lower NOx characteristics compared with a 45 degree swirler at the same pressure loss. However, the lean stability and combustion efficiency in the near weak extinction region was not as good. With swirl the central recirculation zone enhanced the combustion efficiency. For all the swirl vane angles there was little difference in combustion inefficiency between the swirlers. However, the NOx emissions were reduced at the lowest swirl angles and vane angles in the range 20–30 degrees were considered to be the optimum for central injection. NOx emissions for central injection as low as 5ppm at 15% oxygen and 1 bar were demonstrated for zero swirl and 20 degree swirler vane angle. This would scale to well under 25 ppm at pressure for all current industrial gas turbines.

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.

The Influence of Coal Slurry Fuel Properties on the Performance of a Bench Scale Two-Stage Slagging Combustor

1992 ◽  
Author(s):  
L. H. Cowell ◽  
C. S. Wen ◽  
R. T. LeCren
Keyword(s):  
Pollutant Emissions ◽  
Test Facility ◽  
Inlet Temperature ◽  
Coal Slurry ◽  
Particulate Emissions ◽  
Two Stage ◽  
Bench Scale ◽  
Air Inlet ◽  
Primary Zone ◽  
Secondary Zone

Fuel specifications for a coal-fueled industrial gas turbine are being determined through bench scale testing of a two-stage slagging combustor with coal water mixtures (CWM) possessing different properties. Twelve CWMs have been formulated with variations in coal loading, ash concentration, fuel additives, coal particle size, and coal type. The test combustor is operated at 7 bars with a 600 K air inlet temperature in a high pressure test facility. The two-stage slagging combustor (TSSC) features a rich burning, slagging primary zone and a lean secondary zone. Combustor performance is characterized by measurements of pollutant emissions, slag capture, particulate emissions, and coal utilization. The combustor has demonstrated a high degree of fuel property flexibility with performance remaining above goals in most tests. The properties of the CWMs and the test results are discussed.

OH* Chemiluminescence and OH-PLIF Measurements in a Micro Gas Turbine Combustor

2010 ◽  
Author(s):  
Martina Hohloch ◽  
Rajesh Sadanandan ◽  
Axel Widenhorn ◽  
Wolfgang Meier ◽  
Manfred Aigner
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Thermal Power ◽  
Gas Turbine Combustor ◽  
Maximum Heat ◽  
Micro Gas Turbine ◽  
Power Load ◽  
Reaction Zones ◽  
Maximum Heat Release

In this work the combustion behavior of the Turbec T100 natural gas/air combustor was analyzed experimentally. For the visualization of the flame structures at various stationary load points OH* chemiluminescence and OH-PLIF measurements were performed in a micro gas turbine test rig equipped with an optically accessible combustion chamber. The OH* chemiluminescence measurements are used to get an impression of the shape and the location of the heat release zones. In addition the OH-PLIF measurements enabled spatially and temporarily resolved information of the reaction zones. Depending on the load point the shape of the flame was seen to vary from cylindrical to conical. With increasing thermal power load the maximum heat release zones shift to a lifted flame. Moreover, the effect of the optically accessible combustion chamber on the performance of the micro gas turbine is evaluated.

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.

High Performance and Cost Effective Recuperator for Micro-Gas Turbines

2002 ◽  
Author(s):  
Gunnar Lagerstro¨m ◽  
Max Xie
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Performance ◽  
Electrical Power ◽  
Cost Effective ◽  
Piping System ◽  
Micro Gas Turbine ◽  
Air Inlet ◽  
Manufacturing Technologies ◽  
Air Cells

Rekuperator Svenska AB owned by VOLVO Technology Transfer Corporation and Avesta Polarit, has successfully developed a completely laser welded recuperator for micro-gas turbine applications. Tests have shown that the thermal performance is very competitive. The recuperator was installed in a 100 kW(e) micro-gas turbine power plant for combined electricity and heat generation by a customer. The recuperator is a primary surface counter flow heat exchanger with cross corrugated duct configuration. The primary heat transfer surface plate patterns are stamped and a pair of the plates are laser welded to form an air cell. The air cells are then stacked and laser welded together to form the recuperator core which is tied between two end beams. Manifolds for air inlet and outlet as well as piping system are welded to the core. Through varying the number of air cells the recuperator core can easily be adapted for micro-gas turbine applications with different output rates of electrical power. The key manufacturing technologies are stamping of the air cell plates and laser welding of the air cells. These processes can be fully automated for mass production at low costs.

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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