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1

Efficiency optimisation of blade shape in steam and ORC turbines

Lampart P., Witanowski Ł., Klonowicz P.

Mechanics and Mechanical Engineering

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2018

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Vol. 22, nr 2

553--564

EN

This paper is devoted to direct constrained optimisation of blading systems of large power and small power turbines so as to increase their internal efficiency. The optimisation is carried out using hybrid stochastic-deterministic methods such as a combination of a direct search method of Hooke-Jeeves and simulated annealing or a combination of a bat algorithm and simplex method of Nelder-Mead. Among free shape parameters are blade number and stagger angle, stacking blade line parameters and blade section (profile) parameters. One practical example of efficiency optimisation of turbine blading systems is modification of low load profiles PLK-R2 for high pressure (HP) stages of large power steam turbines. Another optimised geometry is that of an ORC radial-axial cogeneration turbine of 50 kWe. Up to 1% efficiency increase can easily be obtained from optimization of HP blade profiles, especially by making the rotor blade more aft-loaded and reducing the intensity of endwall flows. Almost 2% efficiency rise was obtained for the optimized 50 kWe ORC turbine due to flow improvement at the suction side of the blade.

2

The Flow Path of 7CK65 Steam Turbine for a Combined Cycle Power Plant

Łuniewicz B., Obrzut D., Szyrejko C., Kietliński K., Gardzilewicz A.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

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2005

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nr 128, vol. 2

345-356

EN

Description of a modern design of 65 MW impulse steam turbine is presented in the paper. The construction of the turbine makes use of own highly-loaded profiles, which allow reducing the total number of stages and locating the entire flow system in one casing. The a/m turbine has been designed and manufactured at the ALSTOM Power Elbląg Design Office and applied in practice to the combined cycle unit at Zielona Góra Heat and Power Station (H&PS). The performed heat measurements confirmed the guaranteed high performance.

3

Efekty zmiany ułopatkowania kierownicy akcyjnego stopnia turbinowego

Wiechowski S.

Gospodarka Paliwami i Energią

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2001

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nr 2

22-29

PL

W powietrznej turbinie modelowej zbadano i porównano charakterystyki dwóch stopni akcyjnych oraz kierownic, które różniły się profilami łopatek, katem ich ustawienia i podziałką przy zachowaniu podobnej powierzchni wylotowej wieńca A1.

EN

The characteristics of two impulse stage and their guide vanes are tested in cold air turbine and compared. The both guide wheels have different blade profiles, position angles and pitches and simular autlat stator plane A1.

4

Determination of the field of constrain forces representing the effect of the impeller's blading

Czibere T., Kalmár L.

Computer Assisted Mechanics and Engineering Sciences

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1999

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Vol. 6, No. 3-4

321-327

EN

The aim of this paper is to present a numerical method to determine a field of constrain forces which hydrodynamically represents the effect to the blading of the impeller of a radial-flow pump. The field of constrain forces are perpendicular to the stream surfaces of the relative velocity field and congruent to the blade surface of the impeller. The calculation of the constrain force field is based on the solution of the inverse problem of the hydrodynamic cascade theory. In the determination of the constrain force it is supposed that the frictionless and incompressible fluid flow is completely attached to the blade surfaces. The constrain force field can be calculated by the change of the moment of momentum in the absolute inviscid fluid flow which depends on the state of the pump. Knowing the constrain force field it is possible to calculate the distributions of the relative velocity, pressure and energy loss on the mean stream surface (F) of the impeller by solving the governing equations of the viscous relative flow. By calculating the energy loss belonging to different volume rates an approximate real head-discharge characteristic of the impeller also can be computed.

5

Protective coatings for high temperature applications.

Singheiser L., Quadakkers W.J., Clemens D., Steinbrech R.W.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

955-962

EN

The improvement of efficiencies of land based gas turbines requires a significant increase of gas inlet temperature. This results in an increased service temperature of the blading materials and consequently to an enhanced oxidation attack of the blade coatings, which are usually of the NiCoCrAlY type. These coatings can act as protection against oxidation/corrosion and as bond coats for zirconia based thermal barrier systems. In both applications slow growth rates and optimum adherence of the alumina scales forming on the NiCoCrAlY coating during high temperature service are of crucial importance for component life. The mentioned technologically relevant properties of the alumina scales not only strongly depend on the coatings base composition but also on the presence of minor and trace elements. In the present paper this will be illustrated by showing as examples the effect of minor changes in yttrium and titanium content on MCrAlY oxidation properties. The coatings were tested by cyclic oxidation in the temperature range 950 degrees centigrade - 1100 degrees centigrade. The effect of the composition variation was studied by characterisation of the bulk coating and the corrosion products using light and electron optical microscopy as well as dilatometry.