scholarly journals Low-pressure-ratio regenerative exhaust-heated gas turbine

1991 ◽  
Author(s):  
L.A. Tampe ◽  
R.G. Frenkel ◽  
D.J. Kowalick ◽  
H.M. Nahatis ◽  
S.M. Silverstein ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Low Pressure

scholarly journals Low-pressure-ratio regenerative exhaust-heated gas turbine. Final report

1991 ◽  
Author(s):  
L.A. Tampe ◽  
R.G. Frenkel ◽  
D.J. Kowalick ◽  
H.M. Nahatis ◽  
S.M. Silverstein ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Final Report

Proe 90™ Recuperator for Microturbine Applications

2002 ◽  
Author(s):  
Richard A. Proeschel
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Performance ◽  
Low Cost ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Tube Length ◽  
Distributed Power ◽  
Parametric Data

Microturbines are becoming increasingly important in the distributed power generation market. These machines are typically low pressure ratio gas turbines that require a recuperator to achieve the high, 30% or more, efficiency needed to compete in this market. However, the additional efficiency gained by a recuperator can easily be offset by its high initial cost. In response to this challenge, Proe Power Systems has developed, and has a U.S. patent pending on, the Proe 90™ gas turbine recuperator. The principal feature of the Proe 90™ recuperator is that it allows a high performance (high temperature, high effectiveness, low pressure drop) gas turbine recuperator to be manufactured by simply welding, brazing, or otherwise joining standard commercial tubing without the need for special tooling or manufacturing processes. The objective in developing the Proe 90™ recuperator was to provide a recuperator for gas turbine and related applications that can attain a minimum of 90% effectiveness with reasonable size and minimal cost. It meets those objectives by: having linear, counterflow, annular flow paths that avoid any thermal “short circuits”; by having sufficient margin to accommodate potential exhaust gas fouling of the low pressure flow passages; by having all surfaces either curved or stayed by flow tubes so that they can be made from commercially available tube and sheet stock while maintaining high margins of strength and creep resistance; and by avoiding thermal gradient stresses by having all non-isothermal portions of the recuperator able to freely expand and contract. The simple manufacturing process, design modeling techniques and predicted performance of the Proe 90™ recuperator are presented. Effects of tube length, diameter, and numbers of tubes on effectiveness and pressure losses are quantified. Additional parametric data show the effectiveness losses caused by axial conduction, flow misdistribution, manufacturing tolerances, and insulation losses. The Proe 90™ recuperator is ideally suited for microturbine distributed power applications in the 20–50 kW range. With properly sized tubes, the flow regime is laminar and results in a very small pressure loss while still producing very high heat exchanger effectiveness in a low cost, compact package.

scholarly journals Analysis and Improvement of a Two-Stage Centrifugal Compressor Used in an MW-Level Gas Turbine

2018 ◽  
Vol 8 (8) ◽  
pp. 1347 ◽  
Author(s):  
Wei Zhu ◽  
Xiao-Dong Ren ◽  
Xue-Song Li ◽  
Chun-Wei Gu
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Two Stage ◽  
Vaned Diffuser ◽  
Pressure Stage ◽  
Optimization System ◽  
High Pressure Stage

The performance of a low/high-pressure-stage centrifugal compressor in a land-use MW-level gas turbine with a pressure ratio of approximately 11 is analyzed and optimized with a 1D aerodynamic design and modeling optimization system. 1D optimization results indicate that the diameter ratio of the low-pressure-stage centrifugal compressor with a vane-less diffuser, and the divergent angle of the high-pressure-stage centrifugal compressor with a vaned diffuser, are extremely large and result in low efficiency. Through modeling design and optimization system analysis, a tandem vaned diffuser is used in the low-pressure stage, and a tandem vaned diffuser with splitter vanes is adopted in the high-pressure stage. Computational fluid dynamics (CFD) results show that the pressure ratio and efficiency of the optimized low/high-pressure-stage centrifugal compressor are significantly improved. Coupling calculations of the low/high-pressure stage of the original and optimized designs are conducted based on the results of MW-level gas turbine cycles. CFD results show that the pressure ratio and efficiency of the optimized two-stage centrifugal compressor increase by approximately 8% and 4%, respectively, under three typical load conditions of 100%, 90%, and 60%.

Numerical assessment of the performance of a heat exchanger for a low pressure ratio gas turbine

Energy ◽  
2018 ◽  
Vol 164 ◽  
pp. 171-182 ◽  
Author(s):  
Christina Salpingidou ◽  
Dimitrios Misirlis ◽  
Zinon Vlahostergios ◽  
Michael Flouros ◽  
Stefan Donnerhack ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Numerical Assessment

scholarly journals Blade Roughness Effects on Compressor and Engine Performance—A CFD and Thermodynamic Study

Aerospace ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 330
Author(s):  
Jasem Alqallaf ◽  
Joao A. Teixeira
Keyword(s):  
Surface Roughness ◽  
Gas Turbine ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Low Pressure ◽  
Performance Degradation ◽  
Simulation Software ◽  
Operating Conditions ◽  
Blade Surface ◽  
Pressure Compressor

Degradation of compressors is a common concern for operators of gas turbine engines (GTEs). Surface roughness, due to erosion or fouling, is considered one of the major factors of the degradation phenomenon in compressors that can negatively affect the designed pressure rise, efficiency, and, therefore, the engine aero/thermodynamic performance. The understanding of the aerodynamic implications of varying the blade surface roughness plays a significant role in establishing the magnitude of performance degradation. The present work investigates the implications due to the degradation of the compressor caused by the operation in eroding environments on the gas turbine cycle performance linking, thereby, the compressor aerodynamics with a thermodynamic cycle. At the core of the present study is the numerical assessment of the effect of surface roughness on compressor performance employing the Computational Fluid Dynamics (CFD) tools. The research engine test case employed in the study comprised a fan, bypass, and two stages of the low pressure compressor (booster). Three operating conditions on the 100% speed-line, including the design point, were investigated. Five roughness cases, in addition to the smooth case, with equivalent sand-grain roughness (Ks) of 15, 30, 45, 60, and 150 µm were simulated. Turbomatch the Cranfield in-house gas turbine performance simulation software, was employed to model the degraded engine performance. The study showed that the increase in the uniform roughness is associated with sizable drops in efficiency, booster pressure ratio (PR), non-dimensional mass flow (NDMF), and overall engine pressure ratio (EPR) together with rises in turbine entry temperature (TET) and specific fuel consumption (SFC). The performance degradation evaluation employed variables such as isentropic efficiency (ηis), low pressure compressor (LPC) PR, NDMF, TET, SFC, andEPR. The variation in these quantities showed, for the maximum blade surface degradation case, drops of 7.68%, 2.62% and 3.53%, rises of 1.14% and 0.69%, and a drop of 0.86%, respectively.

Modeling and Performance Analysis of a Dual-Shaft Counter-Rotating Gas Turbine

2018 ◽  
Author(s):  
Qiao Zhou ◽  
Zhao Yin ◽  
Chun-qing Tan ◽  
Qing Gao ◽  
Yong-sheng Tian
Keyword(s):  
High Pressure ◽  
Performance Analysis ◽  
Gas Turbine ◽  
Rotational Speed ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Modeling Method ◽  
Speed Ratio ◽  
Shaft Speed ◽  
Wide Range

This paper proposes a modeling method for the 1+1/2 vaneless counter rotating turbine (VCRT) and carries out performance analysis of a micro gas turbine (MGT) with VCRT at off design conditions. The first task of this paper is to obtain performance characteristics maps and develop a characteristics modeling method of VCRT. The VCRT characteristics maps are obtained through 3-D CFD calculation. High pressure turbine (HPT) corrected rotational speed, shaft rotating speed ratio defined as the high pressure (HP) shaft rotational speed divided by low pressure (LP) shaft rotational speed, and the VCRT total expansion pressure ratio are selected to model a 3-D low pressure turbine (LPT) characteristics maps. However, the HPT characteristics map modeling method remains the same as the conventional one. An overall performance simulation model is established in Matlab/Simulink and validated by software GasTurb. The VCRT engine consumes fuel at a higher rate when delivering same power compared with the conventional gas turbine due to LPT performance degradation. When the relative LP shaft speed ranges from 100% to 96%, the performance of the VCRT engine and conventional engine is almost equivalent. As the LP shaft speed continues to drop off, however, the VCRT engine performance degrades considerably. The results indicate that it is crucial to design VCRT with a wide range of efficiency, especially the LPT. The VCRT engine control law also must be effectively optimized to ensure the engine performs well at part load working conditions.

scholarly journals 5 MW Closed Cycle Gas Turbine

1984 ◽  
Author(s):  
John L. Mason ◽  
Anthony Pietsch ◽  
Theodore R. Wilson ◽  
Allen D. Harper
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Oil Recovery ◽  
Low Cost ◽  
Pressure Ratio ◽  
Commercial Application ◽  
Solid Fuels ◽  
Closed Cycle ◽  
Emission Standards ◽  
Fluidized Bed Combustor

A novel closed-cycle gas turbine power system is now under development by the GWF Power Systems Company for cogeneration applications. Nominally the system produces 5 megawatts (MW) of electric power and 80,000 lb/hr (36,287 kg/hr) of 1000 psig (6895 kPa) steam. The heat source is an atmospheric fluidized bed combustor (AFBC) capable of using low-cost solid fuels while meeting applicable emission standards. A simple, low-pressure ratio, single spool, turbomachine is utilized. This paper describes the system and related performance, as well as the development and test efforts now being conducted. The initial commercial application of the system will be for Enhanced Oil Recovery (EOR) of the heavy crudes produced in California.

scholarly journals Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Low Noise ◽  
Closed Cycle ◽  
Propulsion Systems ◽  
Component Design ◽  
Readiness Level ◽  
Aerial Vehicle ◽  
Turbine Design

When selecting a design for an unmanned aerial vehicle, the choice of the propulsion system is vital in terms of mission requirements, sustainability, usability, noise, controllability, reliability and technology readiness level (TRL). This study analyses the various propulsion systems used in unmanned aerial vehicles (UAVs), paying particular focus on the closed-cycle propulsion systems. The study also investigates the feasibility of using helium closed-cycle gas turbines for UAV propulsion, highlighting the merits and demerits of helium closed-cycle gas turbines. Some of the advantages mentioned include high payload, low noise and high altitude mission ability; while the major drawbacks include a heat sink, nuclear hazard radiation and the shield weight. A preliminary assessment of the cycle showed that a pressure ratio of 4, turbine entry temperature (TET) of 800 °C and mass flow of 50 kg/s could be used to achieve a lightweight helium closed-cycle gas turbine design for UAV mission considering component design constraints.

scholarly journals A Proper Shape of the Trailing Edge Modification to Solve a Housing Damage Problem in a Gas Turbine Power Plant

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 705
Author(s):  
Thodsaphon Jansaengsuk ◽  
Mongkol Kaewbumrung ◽  
Wutthikrai Busayaporn ◽  
Jatuporn Thongsri
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Structural Dynamics ◽  
Pressure Ratio ◽  
Equivalent Stress ◽  
Total Deformation ◽  
Trailing Edge ◽  
Housing Damage ◽  
The Difference ◽  
Gas Turbine Power Plant

To solve the housing damage problem of a fractured compressor blade (CB) caused by an impact on the inner casing of a gas turbine in the seventh stage (from 15 stages), modifications of the trailing edge (TE) of the CB have been proposed, namely 6.5 mm curved cutting and a combination of 4 mm straight cutting with 6.5 mm curved cutting. The simulation results of the modifications in both aerodynamics variables Cl and Cd and the pressure ratio, including structural dynamics such as a normalized power spectrum, frequency, total deformation, equivalent stress, and the safety factor, found that 6.5 mm curved cutting could deliver the aerodynamics and structural dynamics similar to the original CB. This result also overcomes the previous work that proposed 5.0 mm straight cutting. This work also indicates that the operation of a CB gives uneven pressure and temperature, which get higher in the TE area. The slightly modified CB can present the difference in the properties of both the aerodynamics and the structural dynamics. Therefore, any modifications of the TE should be investigated for both properties simultaneously. Finally, the results from this work can be very useful information for the modification of the CB in the housing damage problem of the other rotating types of machinery in a gas turbine power plant.

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