Effects of New International Formulation on Turbine-Generator Performance Calculations

1968 ◽  
Vol 90 (1) ◽  
pp. 15-20
Author(s):  
K. C. Cotton ◽  
N. R. Deming ◽  
E. H. Garbinski

For the pressure-temperature range of steam turbine operation the new International Formulation properties differ from those in Keenan and Keyes Steam Tables primarily in the values of enthalpy and entropy around 1000 deg F. The deviation is significant at pressures above 2400 psi and diminishes as temperature is both increased and decreased. This paper presents the effect of this deviation in steam properties on steam turbine-generator heat rate and high pressure turbine efficiency. Some test data is presented which indicates the new Formulation is more correct at 1000 deg F.

1962 ◽  
Vol 84 (3) ◽  
pp. 295-304 ◽  
Author(s):  
G. A. Maneatis ◽  
W. H. Barr

This paper describes a digital computer program which processes rapidly all of the data taken during a steam turbine-generator acceptance test. Specifically, it determines all thermodynamic properties of steam and water, computes corrected test heat rate, and finally develops a contract heat rate for purposes of comparison with manufacturer’s guarantees. The application of this program on two 330-megawatt units is discussed. The thinking leading to certain key decisions involving the ultimate approach taken is presented for the benefit of those contemplating a similar effort.


Author(s):  
Thomas P. Winterberger ◽  
Robert A. Ransom

The publication of ASME Performance Test Code 6.2-2004 provided the industry with a Code document dedicated to calculating the performance of a steam turbine in a combined cycle power plant. Power output at specified steam flows and conditions was chosen as the Code’s primary performance parameter. That choice was based on the operating and cycle characteristics of a combined cycle plant operating, where the steam turbine is part of the bottoming cycle operating in a sliding pressure mode that follows ambient conditions and the gas turbine operating profile. This steam turbine generator output, corrected to reference heat consumption, is called Output Performance and is a measurement of steam turbine efficiency. Accompanying this new Code was a new correction methodology that focused on correcting the steam turbine generator output to the reference heat consumption of the cycle. In the development of the overall correction methodology, the corrections associated with high-pressure (HP) steam inlet conditions were given careful attention. The committee developing the Code and methodology concluded that three correction formulations were required to accurately and fairly correct back to the reference heat input of the high-pressure turbine inlet, and to account for changes in the as-built flow capacity versus the design flow capacity. The new correction formulations chosen were: • HP Steam Flow; • HP Steam Temperature; • HP Turbine Flow Capacity. Applying these three corrections on a sliding pressure steam turbine ensures that the output performance is corrected to the true reference high pressure steam heat input to the cycle. If any of these three corrections is excluded the calculated output performance will not be a true representation of the steam turbine efficiency.


Author(s):  
Kazutaka Hayashi ◽  
Hiroyuki Shiraiwa ◽  
Hiroyuki Yamada ◽  
Susumu Nakano ◽  
Kuniyoshi Tsubouchi

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.


1964 ◽  
Vol 179 (1) ◽  
pp. 307-342
Author(s):  
R. U. McCrae ◽  
A. Montague ◽  
M. Douglass

This paper describes a number of programmes for digital computers that have been developed by the authors' firm to eliminate many of the tedious hand calculations which are encountered in the preliminary stages of steam-turbine and condenser design. By their use a considerable amount of the designers' time is saved and fatigue is reduced. These programmes also eliminate mistakes and inaccuracies which may occur in long calculations made by hand. The programmes described have been chosen as being representative of the range of programmes used in preliminary turbine design and optimization and are as follows: a programme to enable steam properties to be calculated, based on the formulae given in the Keenan and Keyes Steam Tables; a programme which can be used to determine the efficiency of small industrial turbines; a feed-heating programme which will carry out the calculations necessary to determine the preliminary energy balance for a feed-heating cycle; a detailed energy-balance programme incorporating turbine-efficiency calculations; a condenser-optimization programme for determination of the ideal parameters to be used in the design of a condenser. The programmes are arranged so that unskilled operators can run them on the computer without the help of an experienced programmer. Facilities are also made available for writing programmes in a simplified form called ‘autocode’ which can be used by an engineer after the briefest of trainings. Some programmes are described in considerable detail to assist others who may wish to write a similar programme or to compare them with programmes of their own. All these programmes have been in regular use for more than three years and have greatly enlarged the scope of investigations which may be carried out in the project stage of the design of a steam-turbine generator and associated power-station equipment.


Author(s):  
Fabien Wlassow ◽  
Francis Leboeuf ◽  
Gilles Leroy ◽  
Nicolas Gourdain ◽  
Ghislaine Ngo Boum

Aerothermal prediction for the high-pressure turbine is challenging because of the complex environment that interacts with the turbine: hot-streak migration, unsteady flow phenomena, fluid/solid thermal coupling and technological details (squealer tip, coolant ejections, fillets, etc.). There is a need to compare their relative impacts on the blade temperature and turbine efficiency prediction. This is the main purpose of this paper. URANS simulations of the flow have been performed with a structured flow solver in a one stage high-pressure turbine. The baseline simulation takes into account the squealer tip and an inlet condition representative of a hot streak generated by the combustion chamber. Other technological details (coolant ejections and fillets) and fluid/solid thermal coupling on the rotor blade are alternatively considered in the simulation in order to quantify their relative contribution. The Chimera technique is used to ease the integration of technological details. The conjugate heat transfer (CHT) problem is solved by means of a code coupling where fluxes and temperatures are exchanged at the blade surface between the fluid dynamics solver and the solid thermal code. Results shows that rotor blade fillets have a little impact on both the blade temperature and the turbine efficiency (less than 1%). On the contrary, taking into account external cooling leads to a modification of radial distribution of loss and loading coefficients and reduces the efficiency by 2%. The blade temperature is also impacted, mainly on the suction side where differences of several per cent with the baseline case are observed. Fluid/solid coupling mainly affects the blade temperature prediction by homogenizing it which induces differences around 3% with the baseline case. To complete the analysis, a post-processing that includes a computation of local entropy production terms is used. It shows that the entropy production is mainly due to turbulent dissipation and allows to identify the reduction of efficiency of the case with cooling as an additional production of entropy where the cooling flow mixes with the main flow.


Author(s):  
Masashi Arai ◽  
Kiyomi Teshima ◽  
Sunao Aoki ◽  
Hiroyuki Yamao

An experimental investigation was conducted through the use of a High Temperature Turbine Developing Unit (HTDU) having the same two stage turbine as the high pressure turbine (HPT) of the AGTJ-100A, to ascertain the aerodynamic performance, cooling characteristics and mechanical reliability. The test was performed in three phases, and the maximum turbine inlet temperature was about 1,573 K. The test results showed that turbine efficiency was 90.2 %, the level of metal temperature for nozzles and blades was as expected, and there was little trouble with the hot parts. This paper will present these test results.


Author(s):  
Steve Ingistov

This paper describes efforts that were implemented in modifying two Steam Turbine Generators (STG) that are presently operating in Watson Cogeneration Company (WCC) Plant. WCC Plant is comprised of four identical GE made Gas Turbine Generators (GTG) and four Heat Recovery Steam Generators (HRSG) designed and fabricated by Vogt. Portion of high pressure steam is expanded inside two Dresser-Rand-made Steam Turbine Generators (STG). The modifications presented in this paper include replacement of six original stages of expansion, introduction of shaft retractable labyrinths/packing and installation of the spill strips around shrouded blades. The modifications of high pressure steam path (except 1st stage blading) were completed in 1992 and modification of rotor steam sealing elements such as shaft labyrinths were completed in April and May 2001. The steam path modification uprated STG from original 34.50MW to present 40MW each. The upgrades of the rotor sealing elements resulted in 2.80% Heat Rate (HR) reduction.


2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Paul F. Beard ◽  
Andy D. Smith ◽  
Thomas Povey

This paper presents an experimental and computational study of the effect of inlet swirl on the efficiency of a transonic turbine stage. The efficiency penalty is approximately 1%, but it is argued that this could be recovered by correct design. There are attendant changes in capacity, work function, and stage total-to-total pressure ratio, which are discussed in detail. Experiments were performed using the unshrouded MT1 high-pressure turbine installed in the Oxford Turbine Research Facility (OTRF) (formerly at QinetiQ Farnborough): an engine scale, short duration, rotating transonic facility, in which M, Re, Tgas/Twall, and N/T01 are matched to engine conditions. The research was conducted under the EU Turbine Aero-Thermal External Flows (TATEF II) program. Turbine efficiency was experimentally determined to within bias and precision uncertainties of approximately ±1.4% and ±0.2%, respectively, to 95% confidence. The stage mass flow rate was metered upstream of the turbine nozzle, and the turbine power was measured directly using an accurate strain-gauge based torque measurement system. The turbine efficiency was measured experimentally for a condition with uniform inlet flow and a condition with pronounced inlet swirl. Full stage computational fluid dynamics (CFD) was performed using the Rolls-Royce Hydra solver. Steady and unsteady solutions were conducted for both the uniform inlet baseline case and a case with inlet swirl. The simulations are largely in agreement with the experimental results. A discussion of discrepancies is given.


Author(s):  
T. Wolf ◽  
K. Lehmann ◽  
L. Willer ◽  
A. Pahs ◽  
M. Rößling ◽  
...  

This paper introduces a new 2-stage high-pressure turbine rig for aerodynamic investigations. It is operated by DLR Göttingen (Germany) and installed in DLR’s new testing facility NG-Turb. The rig’s geometrical size as well as the non-dimensional parameters are comparable to a modern engine in the small to medium thrust range. The turbine rig closely resembles engine hardware and features all relevant blade and vane cooling as well as secondary air-system flows. The effect of variations of each individual flow and different tip clearances on overall turbine efficiency will be studied. While the first part of the testing program will be based on uniform inlet conditions the second part will be run with a combustor simulator, which is based on electrical heaters and delivers a flow field similar to a rich-burn combustor. In order to find the optimum relative position for maximum turbine efficiency the combustor simulator can be rotated relative to the HPT inlet (clocking). For the same reasons the stators can also be clocked. The paper gives a brief overview of the testing facility and from there on focuses on the HPT rig features such as aerodynamic design, cooling and sealing flows. The aerodynamic optimisation of the stator vanes and shroudless rotor blades will be outlined. Further topics are the aerodynamic design of the combustor simulator, a comparison with engine combustors as well as the implementation in the rig. The paper also describes the rig instrumentation in the stationary and rotating system which most importantly focuses on measurements of efficiency and capturing of traverse data. The topic of blade and vane manufacturing via direct metal laser sintering will be briefly covered. The discussion of test results and comparison with numerical simulations will be the subject of a follow-up paper.


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