Single vs. Two Stage High Pressure Turbine Design of Modern Aero Engines

1999 ◽  
Author(s):  
Fathi Ahmad ◽  
Alexander V. Mirzamoghadam
Keyword(s):  
High Reliability ◽  
Pressure Ratio ◽  
Weight Ratio ◽  
Single Stage ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Two Stage ◽  
Cost Weight ◽  
Advantages And Disadvantages ◽  
Secondary Air

In this paper, the two-stage shrouded HPT engine configuration rated at 22000 lbs thrust is used as the baseline from which a single stage HPT unshrouded design is systematically derived to evaluate the potential weight and cost advantage. The baseline thermodynamic cycle at the rated thrust level was modified in order to optimize the turbine inlet temperature, overall pressure ratio, and core flow with a single stage HPT and deliver competitive performance. The comparative study, although preliminary in depth, has led to the advantages and disadvantages associated with an unshrouded single versus a two-stage shrouded HPT design. The results compare design configuration, secondary air system, weight, safety, life, specific fuel consumption (SFC), and future thrust growth capability. The main advantages of the single stage application are reductions in cost and complexity of design, lower turbine gas temperature, and ease of maintenance. The main disadvantages are in reduced turbine polytropic/isentropic efficiency for HPC pressure ratio greater than 9, increased SFC, higher rim speed, higher HPT exit Mach number, higher bypass ratio to achieve the desired thrust level, and possibly higher weight. A quantitative statement on the reduction of engine cost/weight is premature until a detailed design and the associated cost-benefit is performed. The paper concludes by recommending that the design philosophy of the modern unmixed turbofan engine (single or two-stage HPT) leads to a balance between the selected turbine gas temperature versus the by-pass ratio in order to minimize cost and maximize the thrust-to-weight ratio and the cycle efficiency. In either ease, the expected high reliability and reduced engine cost/weight in the context of future thrust-growth capability need to be demonstrated by proven technology which seem to favor the two-stage HPT configuration.

Development of an 8MW-Class High-Efficiency Gas Turbine, M7A-03

2007 ◽  
Author(s):  
Kazuhiko Tanimura ◽  
Naoki Murakami ◽  
Akinori Matsuoka ◽  
Katsuhiko Ishida ◽  
Hiroshi Kato ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
High Reliability ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Gas Temperature ◽  
Turbine Cooling ◽  
Distributed Power Generation

The M7A-03 gas turbine, an 8 MW class, single shaft gas turbine, is the latest model of the Kawasaki M7A series. Because of the high thermal efficiency and the high exhaust gas temperature, it is particularly suitable for distributed power generation, cogeneration and combined-cycle applications. About the development of M7A-03 gas turbine, Kawasaki has taken the experience of the existing M7A-01 and M7A-02 series into consideration, as a baseline. Furthermore, the latest technology of aerodynamics and cooling design, already applied to the 18 MW class Kawasaki L20A, released in 2000, has been applied to the M7A-03. Kawasaki has adopted the design concept for achieving reliability within the shortest possible development period by selecting the same fundamental engine specifications of the existing M7A-02 – mass air flow rate, pressure ratio, TIT, etc. However, the M7A-03 has been attaining a thermal efficiency of greater than 2.5 points higher and an output increment of over 660 kW than the M7A-02, by the improvement in aerodynamic performance of the compressor, turbine and exhaust diffuser, improved turbine cooling, and newer seal technology. In addition, the NOx emission of the combustor is low and the M7A-03 has a long service life. These functions make long-term continuous operation possible under various environmental restraints. Lower life cycle costs are achieved by the engine high performance, and the high-reliability resulting from simple structure. The prototype M7A-03 gas-turbine development test started in the spring of 2006 and it has been confirmed that performance, mechanical characteristics, and emissions have achieved the initial design goals.

Research and Development of 300kW Class Ceramic Gas Turbine (Development of the Static Ceramic Components for CGT303)

1995 ◽  
Author(s):  
Mitsuharu Murota ◽  
Issei Ohhashi ◽  
Yoshiyuki Ito ◽  
Sadao Arakawa
Keyword(s):  
Research And Development ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Important Task ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Turbine Inlet Temperature ◽  
Engine Operation ◽  
Heat Cycle ◽  
Ceramic Components

As the result of setting the low pressure ratio at 4.5, sizes of the static ceramic components forming the gas passage in CGT303 have been increased, and establishing reliability of these components was thought to be the most important task. So, the heat-cycle tests were conducted, in advance of the engine operation, and improvements have been made on their material and constructions. After conducting 600 times of the heat-cycle tests, so far, up to the gas temperature of 1200°C, we have succeeded in the engine operation at the turbine inlet temperature of 1200°C Examples of the problems encountered in the test and of the solutions therefore are introduced in this paper.

scholarly journals Experimental Investigation on the Effect of Varying Purge Flow in a Newly Commissioned Single Stage Turbine Test Facility

2020 ◽  
Author(s):  
Daniel Payne ◽  
Vasudevan Kanjirakkad
Keyword(s):  
Pressure Ratio ◽  
Outer Radius ◽  
Single Stage ◽  
Rotor Blades ◽  
Test Facility ◽  
Rotating Disc ◽  
Radial Temperature ◽  
Turbine Performance ◽  
Purge Flow ◽  
Secondary Air

Abstract In order to produce efficient engines it is essential for gas tur-bine designers to understand the interaction between the primary and secondary air systems in critical parts of the engine. One of these is the first stage turbine, where the ingress of the hot an-nulus air into the rotor stator cavity could be catastrophic due to the increased heat load on the disc posts and on the rotor blades themselves (through reduced cooling). To ensure that this does not happen, contactless seals (rim seals) are built into the outer radius of the rotating disc. Additionally, a secondary air flow rate must be appropriately set in order to ‘purge’ the hot air that could be ingested into the rim seal cavity. However, this purge airflow could cause deterioration of the turbine performance as it re-joins the main annulus flow at the interface between the rim seal cavity and the main annulus. The deterioration in performance is pri-marily due to the difference in kinematic (flow velocity and mass flow) and thermodynamic (density, enthalpy) properties of the two stream of air. It is therefore essential to understand the optimum seal geometry and purge flow rates required to prevent the ingestion of the hot annulus air while maintaining the required turbine performance. In this paper we present experimental test results from a single stage turbine facility, the Rim Seal (RiSe) rig, at the University of Sussex. The turbine stage incorporates a model rotor-stator cavity system that is representative of the first stage turbine in a gas turbine engine. The facility is capable of generating disc cavity rotational Reynolds numbers of the order of 2.2 × 106 and axial Reynolds number of the order of 0.7 × 106, while operating at a pressure ratio of 2.5. The paper will present the salient features of the test facility, the various instrumentation employed, and the operating specifications of the stage. The paper will discuss the effect of varying the purge flow for a fixed operating point of the turbine. Results presented will include typical mission profiles, cavity radial temperature distribution, and the measured cavity sealing effectiveness.

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.

A Methodology for Measuring Turbocharger Adiabatic Maps in a Gas-Stand and its Usage for Calibrating Control Oriented and 1D Models at Early ICE Design Stages

2019 ◽  
Author(s):  
José Ramón Serrano ◽  
Francisco José Arnau ◽  
Luis Miguel García-Cuevas ◽  
Alejandro Gómez-Vilanova ◽  
Stephane Guilain ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Internal Combustion Engines ◽  
Gas Flow ◽  
System Analysis ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Boost Pressure ◽  
Gas Temperature ◽  
Hot Gas ◽  
The Impact

Abstract Turbocharged engines are the standard architecture for designing efficient spark ignition and compression ignition reciprocating internal combustion engines (ICE). Turbochargers characterization and modeling are basic tasks for the analysis and prediction of the whole engine system performance and this information is needed in quite early stages of the engine design. Turbocharger characteristics (efficiency, pressure ratio, mass flow rates...) traditionally rely in maps of pseudo non-dimensional variables called reduced variables. These maps must be used by reciprocating ICE designer and modeler not only for benchmarking of the turbocharger, but for a multiplicity of purposes, i.e: assessing engine back-pressure, boost pressure, load transient response, after-treatment inlet temperature, intercooler inlet temperature, low pressure EGR temperature, ... Maps of reduced variables are measured in gas-stands with steady flow but non-standardized fluids conditioning; neither temperatures nor flows. In concrete: turbine inlet gas temperature; lubrication-oil flow and temperature; water-cooling flow and turbo-machinery external heat transfer are non-standardized variables which have a big impact in assessing said multiplicity of purposes. Moreover, adiabatic efficiency, heat losses and friction losses are important data, hidden in the maps of reduced variables, which depend on the testing conditions as much as on the auxiliary fluids temperature and flow rate. In this work it is proposed a methodology to standardize turbochargers testing based in measuring the maps twice: in close to adiabatic and in diathermal conditions. Along the paper it is discussed with special detail the impact of the procedure followed to achieve said quasi-adiabatic conditions in both the energy balance of the turbocharger and the testing complexity. As a conclusion, the paper proposes a methodology which combines quasi-adiabatic tests (cold and hot gas flow) with diathermal tests (hot gas flow) in order to extract from a turbocharger gas-stand all information needed by engine designers interested in controlling or 1D-modelling the ICE. The methodology is completed with a guide for calibrating said control-oriented turbocharger models in order to separate aerodynamic efficiency (adiabatic) from heat transfer losses and from friction losses in the analysis of the turbocharger performance. The outsourced calibration of the turbocharger model allows avoiding uncertainties in the global ICE model calibration, what is very interesting for turbochargers benchmarking at early ICE-turbo matching stages or for global system analysis at early control design stages.

scholarly journals New Diagram and Equation for Thermodynamic Calculations for Gas Turbines

1984 ◽  
Author(s):  
B. Herrmann
Keyword(s):  
Gas Turbines ◽  
Liquid Fuel ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Iso Standard ◽  
Compressor Pressure Ratio ◽  
German Standard ◽  
Exhaust Gas Temperature ◽  
Acceptance Tests

On basis of ISO-Standard 2314, the German Standard Organisation (DIN) has prepared the German Standard DIN 4341, which deals with acceptance tests for gas turbines. Sample calculations have been included. In connection with the development of the sample calculations a new diagram for thermodynamic properties of air and products of combustion was developed on basis of -humid air as per ISO standard 2314 -standard gaseous fuel -standard liquid fuel This diagram allows exact calculation of performance data. Further, a simplified but relatively acurate formula is presented for calculating the turbine inlet temperature on basis of -compressor pressure ratio -exhaust gas temperature -thermal efficiency Development and limitation of this formula is presented.

Performance Improvement of Small Gas Turbines Through Use of Wave Rotor Topping Cycles

2003 ◽  
Author(s):  
Pezhman Akbari ◽  
Norbert Mu¨ller
Keyword(s):  
Gas Turbines ◽  
Performance Enhancement ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Advantages And Disadvantages ◽  
Turbine Inlet ◽  
Compressor Pressure Ratio ◽  
Significant Performance ◽  
Almost All

Results are presented predicting the significant performance enhancement of two small gas turbines (30 kW and 60 kW) by implementing various wave rotor topping cycles. Five different advantageous implementation cases for a four-port wave rotor into given baseline engines are considered. The compressor and turbine pressure ratios, and the turbine inlet temperatures vary in the thermodynamic calculations, according to the anticipated design objectives of the five cases. Advantages and disadvantages are outlined. Comparison between the theoretic performance (expressed by specific cycle work and overall thermal efficiency) of wave-rotor-topped and baseline engines shows a performance enhancement by up to 33%. The results obtained show that almost all the cases studied benefit from the wave-rotor-topping, but the highest gain is obtained for the case in which the topped engine operates with the same turbine inlet temperature and compressor pressure ratio as the baseline engine. General design maps are generated for the small gas turbines, showing the design space and optima for baseline and topped engines.

scholarly journals Immediate two-stage tissue expander vs single-stage direct-to-implant breast reconstruction: two case reports of identical twins with BRCA 2 mutation

2015 ◽  
Vol 84 (11) ◽  
Author(s):  
Aleš Porčnik ◽  
Uroš Ahčan
Keyword(s):  
Breast Reconstruction ◽  
Case Reports ◽  
Tissue Expander ◽  
Single Stage ◽  
Two Stage ◽  
Aesthetic Result ◽  
Advantages And Disadvantages ◽  
Brca 2 ◽  
Immediate Implant ◽  
Implant Breast Reconstruction

In order to achieve the best aesthetic result after immediate implant-based breast reconstruction, all the advantages and disadvantages of two-stage tissue expander and single-stage direct-to-implant breast reconstruction should be considered. Decision about the type of implant-based reconstruction is based on the consultations outcomes after multidisciplinary team meeting of breast and reconstructive specialist, but patients own wishes should be prioritised.

The Potential of GT Combined Cycles for Ultra High Efficiency

2012 ◽  
Author(s):  
Hans E. Wettstein
Keyword(s):  
High Efficiency ◽  
Pressure Ratio ◽  
Specific Power ◽  
Variable Pressure ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Calculation Results ◽  
Combined Cycles ◽  
Exit Temperature ◽  
Exergy Losses

Gas turbine combined cycles (GTCC) using a steam bottoming cycle are a widely used technology for electric power generation. From [1] it is known that the best current large GTCC’s loose around 25% of the fuel exergy just by combusting the fuel while all other exergy losses sum up to around 15%. For the net efficiency of such plants 60% is remaining. This paper shows thermodynamic calculation results of GTCC’s with variable pressure ratio and turbine inlet temperature (TIT) aimed at understanding the efficiency potential associated with further increases of the TIT thus reducing the exergy loss by combustion. The assumptions of these calculations correspond to published industrial experience and standard assumptions in two different scenarios. The results are curves showing net efficiency and specific power as functions of TIT. Other data like the related pressure ratio and compressor exit temperature are shown too. The conclusion shows that a net efficiency of 63…65% is feasible with a hot gas temperature of around 1750°C based on the two scenarios. The winning cycle arrangement uses an adiabatic compressor. A GTCC with GT-compressor having one intercooling stage is clearly less favorable in several respects.

A Study on Low NOx Combustion in LBG-Fueled 1500°C-Class Gas Turbine

1994 ◽  
Author(s):  
Toshihiko Nakata ◽  
Mikio Sato ◽  
Toru Ninomiya ◽  
Takeharu Hasegawa
Keyword(s):  
Power Generation ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combustion Process ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Secondary Air

Developing integrated coal gasification combined cycle systems ensures cost-effective and environmentally sound options for supplying future power generation needs. The reduction of NOx emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in an Integrated Coal Gasification Combined Cycle (IGCC) power generation systems. The coal gasified fuel, which is produced in a coal gasifier of air-blown entrained-flow type has calorific value as low as 1/10 of natural gas. Furthermore the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. This study is performed in a 1500°C-class gas turbine combustor firing low-Btu coal-gasified fuel in IGCC systems. An advanced rich-lean combustor of 150-MW class gas turbine was designed to hold stable combustion burning low-Btu gas and to reduce fuel NOx emission that is produced from the ammonia in the fuel. The main fuel and the combustion air is supplied into fuel-rich combustion chamber with strong swirl flow and make fuel-rich flame to decompose ammonia into intermediate reactants such as NHi and HCN. The secondary air is mixed with primary combustion gas dilatorily to suppress the oxidization of ammonia reactants in fuel-lean combustion chamber and to promote a reducing process to nitrogen. By testing it under atmospheric pressure conditions, the authors have obtained a very significant result through investigating the effect of combustor exit gas temperature on combustion characteristics. Since we have ascertained the excellent performance of the tested combustor through our extensive investigation, we wish to report on the results.

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