AN ASSESSMENT OF FOUR STAGE AXIAL POWER TURBINE DISKS’ AIR-COOLING SYSTEM BASED ON THERMAL-HYDRAULIC MODELING

Ольга Александровна Фурман, Валерий Юрьевич Бондарчук

Abstract


A hydraulic analysis of four stage axial power turbine cooling system was performed. A practical application of the existing algorithms of thermal-hydraulic analysis is considered. Reasonable flow-rate distribution among the cooling channels and cooling system air leakage waste reduction are discussed. An implementation of the rotor screen dividing rotor internal cavity into disk and shaft cavities is revealed as the best way to keep the flow-rate balance of cooling air in account of achievement simplicity.

This paper also covers a key design concept that the structure of turbine shall be such as to promote good dissipation of heat from blades to disks by means of air flow passing through special channels between rotor parts.

A turbine disks’ air-cooling system assessment importance is shown according to the aim of hot gas ingress prevention. It is given a brief description of known theoretical fundamentals on which the used thermal-hydraulic analysis computational method of modeling was based.

Flow-rate distribution among the four stage axial power turbine disks’ air-cooling system is noted to be carried out by certain basic design choices such as labyrinth seals, fins and ledges. The most important factors on which the flow-rate distribution depends on are mentioned including a ratio of narrow section hydraulic area to channel section hydraulic area, hydraulic resistance and availability of centrifugal pressure between disks.

Narrowing of cooling flow passage section causes air velocity increase and pressure reduction. Even though some recovery of velocity appears downstream the narrowing element, the pressure value changes its magnitude due to vortex losses. Therefore it makes possible to provide the required air distribution.

The considered rotor screen structure confirmed its functionality in operating gas turbine plant and it is stated as achieved results. Numeral details of dealt analysis are omitted.

Generally, the behavior of flow and heat exchange in area between rotating disks is classified as rather complicated and methods of its modeling are summarized to remain relevant question of further studies.


Keywords


turbine; cooling system; flow-rate; screen

References


Ivanov, M. Ya. Vysokotemperaturnye gazovye turbiny [High temperature gas turbines]. Sb. nauch. tr. TsIAM №1342 [Proc. of the Central Scientific-Research Institute of Airplane-Engine Design №1342]. Moscow, TORUS PRESS Publ., 2010. 304 p.

Tarasov, A. I., Chan Kong Shang, Litvinenko, O. A., Mikhailova, I. A. Kompleksnyi metod rascheta sistem okhlazhdeniya rotorov gazovykh turbin [Complex method of rotor cooling system analysys]. Vestn. NTU «KhPI», 2015, no. 15, pp. 63-68.

Chan Kong Shang. Razvitie metodov rascheta sistem okhlazhdeniya rotorov gazovykh turbin. Avtoref. dys. kand. tekhn. nauk [Development of gas turbine rotor cooling systems’ analysis methods]. Kharkov, NTU «KhPI» Publ., 2010. 16 p.

Dolgov, A. I. Teplogidravlicheskoe obosnovanie optimizatsionnoi modeli raschetov sistemy okhlazhdeniya gazovykh turbin. Avtoref. dys. kand. tekhn. nauk [Thermal-hydraulic basis of gas turbine cooling systems’ analysis optimization mod-el]. Kharkov, NTU «KhPI» Publ., 2015. 21 p.

Paskonov, V. M., Polezhaev, V. I. Chudov, L. A. Chislennoe modelirovanie protsessov teplo- i mas-soobmena [Computational modeling of mass-heat exchange processes]. Moscow, Nauka Publ., 1984. 288 p.

Kirakovskii, N. F., Khmel', V. F. Teplotekhnika [Thermal engineering]. Kiev, Vishcha shkola Publ., 1976. 520 p.

Tarasov, A. I., Dolgov, A. I. THA (Thermal & Hy-draulic Analysis). The Certificate on official registration of the computer program, no. 2007610141, 2006. (In Russian, unpublished).

Dolgov, A. I, Tarasov, A. I. Proektirovanie sistem okhlazhdeniya gazovykh turbin [Gas turbines’ cooling systems’ design]. Turbiny i dizeli, Perm', 2010, no. 3, pp. 14-16.

Lokai, V. I. Gazovye turbiny dvigatelei letatel'nykh apparatov: Teoriya, konstruktsiya i raschet [Aircraft engine gas turbines: theory, design and analysis]. Moscow, Mashinostroenie Publ., 1979. 447 p.

Kopelev, S. Z., Slitenko, A. F. Konstruktsii i raschet sistem okhlazhdeniya GTD [Gas turbine engine cooling systems’ design and analysis]. Kharkov, Osnova Publ., 1994. 240 p.




DOI: https://doi.org/10.32620/aktt.2018.8.06