150 kW Class Two-Stage Radial Inflow Condensing Steam Turbine System

2011 ◽  
Author(s):  
Kazutaka Hayashi ◽  
Hiroyuki Shiraiwa ◽  
Hiroyuki Yamada ◽  
Susumu Nakano ◽  
Kuniyoshi Tsubouchi
Keyword(s):  
High Pressure ◽  
Steam Turbine ◽  
Output Power ◽  
Power Output ◽  
Thermal Efficiency ◽  
Rotational Speed ◽  
High Pressure Turbine ◽  
Two Stage ◽  
Electrical Efficiency ◽  
Design Value

A prototype machine for a 150 kW class two-stage radial inflow condensing steam turbine system has been constructed. This turbine system was proposed for use in the bottoming cycle for 2.4 MW class gas engine systems, increasing the total electrical efficiency of the system by more than 2%. The gross power output of the prototype machine on the generator end was 150kW, and the net power output on the grid end which includes electrical consumption of the auxiliaries was 135kW. Then, the total electrical efficiency of the system was increased from 41.6% to 43.9%. The two-stage inflow condensing turbine system was applied to increase output power under the supplied steam conditions from the exhaust heat of the gas engines. This is the first application of the two-stage condensing turbine system for radial inflow steam turbines. The blade profiles of both high- and low-pressure turbines were designed with the consideration that the thrust does not exceed 300 N at the rated rotational speed. Load tests were carried out to demonstrate the performance of the prototype machine and stable output of 150 kW on the generator end was obtained at the rated rotational speed of 51,000 rpm. Measurement results showed that adiabatic efficiency of the high-pressure turbine was less than the design value, and that of the low-pressure turbine was about 80% which was almost the same as the design value. Thrust acting on the generator rotor at the rated output power was lower than 300 N. Despite a lack of high-pressure turbine efficiency, total thermal efficiency was 10.5% and this value would be enough to improve the total thermal efficiency of a distributed power system combined with this turbine system.

Large-Scale Simulation of the Clocking Impact of 2D Combustor Profile on a Two Stage High Pressure Turbine

2014 ◽  
Author(s):  
Thomas E. Dyson ◽  
David B. Helmer ◽  
James A. Tallman
Keyword(s):  
High Pressure ◽  
Large Scale ◽  
High Pressure Turbine ◽  
Cfd Simulations ◽  
Two Stage ◽  
Substantial Impact ◽  
Sliding Mesh ◽  
Wall Flow ◽  
End Wall ◽  
Film Flows

This paper presents sliding-mesh unsteady CFD simulations of high-pressure turbine sections of a modern aviation engine in an extension of previously presented work [1]. The simulation included both the first and second stages of a two-stage high-pressure turbine. Half-wheel domains were used, with source terms representing purge and film flows. The end-wall flow-path cavities were incorporated in the domain to a limited extent. The passage-to-passage variation in thermal predictions was compared for a 1D and 2D turbine inlet boundary condition. Substantial impact was observed on both first and second stage vanes despite the mixing from the first stage blade. Qualitative and quantitative differences in surface temperature distributions were observed due to different ratios between airfoil counts in the two domains.

Aerodynamic Optimization of High Pressure Turbine and Interstage Duct in a Two-Stage Air System for a Heavy-Duty Diesel Engine

2017 ◽  
Author(s):  
Uswah Khairuddin ◽  
Aaron W. Costall
Keyword(s):  
High Pressure ◽  
Diesel Engine ◽  
Operating Point ◽  
Heavy Duty ◽  
Aerodynamic Optimization ◽  
High Pressure Turbine ◽  
Two Stage ◽  
Turbine Wheel ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

Turbochargers are a key technology for reducing the fuel consumption and CO2 emissions of heavy-duty internal combustion engines by enabling greater power density, which is essential for engine downsizing and downspeeding. This in turn raises turbine expansion ratio levels and drives the shift to air systems with multiple stages, which also implies the need for interconnecting ducting, all of which is subject to tight packaging constraints. This paper considers the challenges in the aerodynamic optimization of the exhaust side of a two-stage air system for a Caterpillar 4.4-litre heavy-duty diesel engine, focusing on the high pressure turbine wheel and interstage duct. Using the current production designs as a baseline, a genetic algorithm-based aerodynamic optimization process was carried out separately for the wheel and duct components in order to minimize the computational effort required to evaluate seven key operating points. While efficiency was a clear choice for the cost function for turbine wheel optimization, the most appropriate objective for interstage duct optimization was less certain, and so this paper also explores the resulting effect of optimizing the duct design for different objectives. Results of the optimization generated differing turbine wheel and interstage duct designs depending on the corresponding operating point, thus it was important to check the performance of these components at every other operating point, in order to determine the most appropriate designs to carry forward. Once the best compromise high pressure turbine wheel and interstage duct designs were chosen, prototypes of both were manufactured and then tested together against the baseline designs to validate the CFD predictions. The best performing high pressure turbine design, wheel A, was predicted to show an efficiency improvement of 2.15 percentage points, for on-design operation. Meanwhile, the optimized interstage duct contributed a 0.2 and 0.5 percentage-point efficiency increase for the high and low pressure turbines, respectively.

Unsteady Simulation of a Two-Stage Cooled High Pressure Turbine Using an Efficient Non-Linear Harmonic Balance Method

2013 ◽  
Author(s):  
Venkataramanan Subramanian ◽  
Chad H. Custer ◽  
Jonathan M. Weiss ◽  
Kenneth C. Hall
Keyword(s):  
High Pressure ◽  
Harmonic Balance ◽  
Nearest Neighbor ◽  
Harmonic Balance Method ◽  
Balance Method ◽  
High Pressure Turbine ◽  
Two Stage ◽  
Nearest Neighbor Algorithm ◽  
Blade Row ◽  
Unsteady Simulation

The harmonic balance method is a mixed time domain and frequency domain approach for efficiently solving periodic unsteady flows. The implementation described in this paper is designed to efficiently handle the multiple frequencies that arise within a multistage turbomachine due to differing blade counts in each blade row. We present two alternative algorithms that can be used to determine which unique set of frequencies to consider in each blade row. The first, an all blade row algorithm, retains the complete set of frequencies produced by a given blade row’s interaction with all other blade rows. The second, a nearest neighbor algorithm, retains only the dominant frequencies in a given blade row that arise from direct interaction with the adjacent rows. A comparison of results from a multiple blade row simulation based on these two approaches is presented. We will demonstrate that unsteady blade row interactions are accurately captured with the reduced frequency set of the nearest neighbor algorithm, and at a lower computational cost compared to the all blade row algorithm. An unsteady simulation of a two-stage, cooled, high pressure turbine cascade is achieved using the present harmonic balance method and the nearest neighbor algorithm. The unsteady results obtained are compared to steady simulation results to demonstrate the value of performing an unsteady analysis. Considering an unsteady flow through a single blade row turbine blade passage, it is further shown that unsteady effects are important even if the objective is to obtain accurate time-averaged integrated values, such as efficiency.

Performance of a Novel Semiclosed Gas-Turbine Refrigeration Combined Cycle

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Joseph J. Boza ◽  
William E. Lear ◽  
S. A. Sherif
Keyword(s):  
High Pressure ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Combined Cycle ◽  
Water Mixture ◽  
Absorption Refrigeration ◽  
Ambient Conditions ◽  
Large Engine

A thermodynamic performance analysis was performed on a novel cooling and power cycle that combines a semiclosed gas turbine called the high-pressure regenerative turbine engine (HPRTE) with an absorption refrigeration unit. Waste heat from the recirculated combustion gas of the HPRTE is used to power the absorption refrigeration cycle, which cools the high-pressure compressor inlet of the HPRTE to below ambient conditions and also produces excess refrigeration depending on ambient conditions. Two cases were considered: a small engine with a nominal power output of 100kW and a large engine with a nominal power output of 40MW. The cycle was modeled using traditional one-dimensional steady-state thermodynamics, with state-of-the-art polytropic efficiencies and pressure drops for the turbomachinery and heat exchangers, and curve fits for properties of the LiBr-water mixture and the combustion products. The small engine was shown to operate with a thermal efficiency approaching 43% while producing 50% as much 5°C refrigeration as its nominal power output (roughly 50tons) at 30°C ambient conditions. The large engine was shown to operate with a thermal efficiency approaching 62% while producing 25% as much 5°C refrigeration as its nominal power output (roughly 20,000tons) at 30°C ambient conditions. Thermal efficiency stayed relatively constant with respect to ambient temperature for both the large and small engines. It decreased by only 3–4% as the ambient temperature was increased from 10°Cto35°C in each case. The amount of external refrigeration produced by the engine sharply decreased in both engines at around 35°C, eventually reaching zero at roughly 45°C in each case for 5°C refrigeration. However, the evaporator temperature could be raised to 10°C (or higher) to produce external refrigeration in ambient temperatures as high as 50°C.

Experimental Characterisation of a Humidified T100 Micro Gas Turbine

2016 ◽  
Author(s):  
Marina Montero Carrero ◽  
Ward De Paepe ◽  
Jan Magnusson ◽  
Alessandro Parente ◽  
Svend Bram ◽  
...  
Keyword(s):  
Power Output ◽  
Rotational Speed ◽  
Gas Turbines ◽  
Electrical Power ◽  
Water Injection ◽  
Hot Water ◽  
Electrical Efficiency ◽  
Exhaust Gases ◽  
Heat Demand ◽  
Experimental Characterisation

Despite the potential of micro Gas Turbines (mGTs) for Combined Heat and Power (CHP), this technology still poses limitations that curb its widespread adoption, especially for applications with a variable heat demand. In fact, whenever the user heat demand is low, mGTs are generally shut down. Otherwise, the high temperature exhaust gases have to be blown off and the resulting electrical efficiency is not high enough to sustain a profitable operation. If, instead of released, the heat in the exhaust gases is re-inserted in the cycle — by injecting hot water and transforming the mGT into a micro Humid Air Turbine (mHAT) — the electrical efficiency can be increased during periods of reduced heat demand, thus improving the economics of the technology. Although the enhanced performance of the mHAT cycle has been thoroughly investigated from a numerical point of view, results regarding the experimental behaviour of this technology remain scarce. In this paper, we present the experimental characterisation of the mHAT located at the Vrije Universiteit Brussel (VUB): based on the T100 mGT and equipped with a spray saturation tower. These are the first experimental results of such an engine working at nominal load with water injection. In addition, the control system of the unit has been modified so that it can operate either at constant electrical power output (the default setting) or at constant rotational speed. The latter option allowed to better assess the effect of water injection. Eperimental results demonstrate the patent benefits of water injection on mGT performance: at fixed rotational speed, the power output of the mHAT increases by more than 30%while the fuel consumption rises only by 11%. Overall, the electrical efficiency in wet operation increases by up to 4.2% absolute points. Future work will involve further optimising the current facility to reduce pressure losses in the air and water circuits. In addition, we will carry out transient simulations and experiments in order to further characterise the facility.

Disc Design and Air System Comparison Between a Single and a Two Stage High Pressure Turbine Aero Engine

2000 ◽  
Author(s):  
Fathi Ahmad ◽  
Alexander V. Mirzamoghadam
Keyword(s):  
High Pressure ◽  
Boundary Conditions ◽  
Cover Plate ◽  
High Pressure Turbine ◽  
Two Stage ◽  
Know How ◽  
Aero Engine ◽  
Structural Tests ◽  
Cooling Air ◽  
Effective Design

The design of the high pressure turbine (HPT) module of an aero engine and the method used to predict disc life and burst margin are different among the manufactures. In this paper, two different disc design methods are presented and compared, namely, the strain instability and the Chambers methods. The results of the disc study show that the strain instability method introduces low disc weight compared to the Chambers method. Both methods satisfy the burst speed requirement of 125% of the red line limit speed. The strain instability method was applied to design the disc of a single stage (SS) and of a two stage (TS) HPT configuration. The design philosophy of the SS is to run the HPT with a high rpm and a low SOT, whereas the TS design is based on low rpm and high SOT. The disc preliminary design considered the mechanical boundary conditions only without a temperature gradient. The total boundary conditions (thermal and mechanical) were then applied to the detailed disc design. A comparison between the two applied air systems of the SS and the TS design configuration was also performed. In comparing the two, the SS presents a design with low cooling air consumption, and it is also found that a cover plate is necessary for the front side of the SS configuration. The results of this study could be useful for the design engineer to know how and what is needed to accomplish a safe and effective design. Complementary thermal and structural tests should be performed to identify the limits and benefits of each approach.

Creep Deformation of High Pressure Steam Turbine Part

2015 ◽  
Vol 732 ◽  
pp. 187-190
Author(s):  
František Straka ◽  
Pavel Albl ◽  
Pavel Pánek
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Steam Turbine ◽  
Creep Deformation ◽  
Steam Turbines ◽  
High Pressure Turbine ◽  
High Pressure Steam ◽  
Pressure Steam ◽  
Temperature Levels ◽  
Steam Parameters

Steam turbines are complex rotating machines working at high pressure and high temperature levels. Their high-pressure parts, which are subjected to the highest steam parameters, are most affected by these conditions and may suffer from creep deformation. Permanent changes in geometry become visible in high-pressure turbine casings when they are disassembled after certain time in operation.

Microturbine Rotational Speed Selection

2013 ◽  
Author(s):  
C. Rodgers
Keyword(s):  
Permanent Magnet ◽  
Output Power ◽  
Thermal Efficiency ◽  
Rotational Speed ◽  
High Speed ◽  
Mechanical Design ◽  
Pressure Ratio ◽  
Direct Drive ◽  
Power Turbine ◽  
Speed Selection

This paper delves upon the Aero-Thermodynamic performance and Mechanical design aspects of microturbines comprising a single shaft radial compressor driven by a single stage radial inflow turbine with a combustor and recuperator sized to directly drive a permanent magnet type high speed generator with an output power in the 5–10KW bracket and commensurate rotational speeds in the 100–200 krpm range. It is initially shown that stipulation of a cycle design point output power, turbine inlet or exit temperatures, and compressor pressure ratio delivering optimum thermal efficiency inherently confines rotational speed selection, and that independent rotational speed choice away from those identified optimum speed regimes may result in cycle thermal efficiency compromises. Confining the cycle analysis within temperature limits of cost competitive superalloys and foil materials reveals that the achievement of optimum thermal efficiency is more dependent on temperature at the turbine exit rather than at inlet. Albeit the choice of rotational speed is of particular importance in the compressor and turbine design it moreover is dominant in the mechanical design of the rotating assembly in terms of high speed bearing life and shaft dynamic stability. As a consequence rotating assembly and bearing design options suitable for direct drive permanent magnet generators are reviewed and recommendations offered as to the prime candidate assemblies for future microturbines in the 5.0 to 10.0 kW power output range.

CFD Aerodynamic Performance Validation of a Two-Stage High Pressure Turbine

2011 ◽  
Author(s):  
Murari Sridhar ◽  
Sathish Sunnam ◽  
Shraman Goswami ◽  
Jong S. Liu
Keyword(s):  
High Pressure ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Aerodynamic Performance ◽  
High Pressure Turbine ◽  
Two Stage ◽  
Design Point ◽  
Analysis And Design ◽  
Improve Analysis ◽  
Performance Validation

In the continual effort to improve analysis and design techniques, Honeywell is investigating on the use of CFD to predict the aerodynamic performance of a high pressure turbine. The present study has a two fold objective. The first objective is to validate the commercially available CFD codes for aerodynamic performance prediction of a two-stage high pressure turbine at design and off-design points. The other objective is to establish guidelines to help the designer to successfully.set-up and execute the suitable CFD model analysis. The validation to model the stage interfaces is performed with three different types of approaches such as Mixing Plane approach, Frozen Rotor approach and NonLinear Harmonic approach. The film holes on the blade surface, hub and the shroud walls are modeled by using source term cooling and actual film hole modeling techniques for all the analysis. The validation is accomplished with the test results of a two-stage high pressure turbine, Energy Efficient Engine (E3). The aerodynamic performance data at a design point and typical off-design point are taken as test cases for the validation study. One dimensional performance parameters such as corrected mass flow rate, total pressure ratio, cycle efficiency along with two dimensional spanwise distribution of total pressure, total temperature which are obtained from CFD results are compared with test data. Flow field results are presented to understand the aerodynamic behavior.

Adapting Gas Turbines to Zero Emission Oxy-Fuel Power Plants

2008 ◽  
Author(s):  
Roger E. Anderson ◽  
Scott MacAdam ◽  
Fermin Viteri ◽  
Daniel O. Davies ◽  
James P. Downs ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Natural Gas ◽  
Steam Turbine ◽  
Output Power ◽  
Gas Turbines ◽  
Power Plants ◽  
Low Pressure ◽  
Inlet Temperature ◽  
Zero Emission

Future power plants will require some type of carbon capture and storage (CCS) system to mitigate carbon dioxide (CO2) emissions. The most promising technologies for CCS are: oxy-fuel (O-F) combustion, pre-combustion capture, and post-combustion capture. This paper discusses the recent work conducted by Siemens Power Generation, Florida Turbine Technologies, Inc. (FTT) and Clean Energy Systems, Inc. (CES) in adapting high temperature gas turbines to use CES’s drive gases in high-efficiency O-F zero emission power plants (ZEPPs). CES’s O-F cycle features high-pressure combustion of fuel with oxygen (O2) in the presence of recycled coolant (water, steam or CO2) to produce drive gases composed predominantly of steam and CO2. This cycle provides the unique capability to capture nearly pure CO2 and trace by-products by simple condensation of the steam. An attractive O-F power cycle uses high, intermediate and low pressure turbines (HPT, IPT and LPT, respectively). The HPT may be based on either current commercial or advanced steam turbine technology. Low pressure steam turbine technology is readily applicable to the LPT. To achieve high efficiencies, an IPT is necessary and efficiency increases with inlet temperature. The high-temperature IPT’s necessitate advanced turbine materials and cooling technology. O-F plants have an abundance of water, cool steam ∼200°C (400°F) and CO2 that can be used as cooling fluids within the combustor and IPT systems. For the “First Generation” ZEPP, a General Electric J79 turbine, minus the compressor, to be driven directly by CES’s 170 MWt high-pressure oxy-fuel combustor (gas generator), has been adapted. A modest inlet gas temperature of 760°C (1400°F) was selected to eliminate the need for turbine cooling. The J79 turbine operating on natural gas delivers 32 MWe and incorporates a single-stage free-turbine that generates an additional 11 MWe. When an HPT and an LPT are added, the net output power (accounting for losses) becomes 60 MWe at 30% efficiency based on lower heating value (LHV), including the parasitic loads for O2 separation and compression and for CO2 capture and compression to 151.5 bar (2200 psia). For an inlet temperature of 927°C (1700°F), the nominal value, the net output power is 70 MWe at 34% efficiency (LHV). FTT and CES are evaluating a “Second Generation” IPT with a gas inlet temperature of 1260°C (2300°F). Predicted performance values for these plants incorporating the HPT, IPT and the LPT are: output power of approximately 100–200 MWe with an efficiency of 40 to 45%. The “Third Generation” IPT for 2015+ power plants will be based on the development of very high temperature turbines having an inlet temperature goal of 1760°C (3200°F). Recent DOE/CES studies project such plants will have LHV efficiencies in the 50% range for natural gas and HHV efficiencies near 40% for gasified coal.

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