Effect of heat transfer coefficient of steam turbine rotor on thermal stress field under off-design condition

doi:10.1007/s11708-015-0385-3

Front. Energy

2016, Vol. 10

Issue (1) : 57-64 https://doi.org/10.1007/s11708-015-0385-3

RESEARCH ARTICLE

Effect of heat transfer coefficient of steam turbine rotor on thermal stress field under off-design condition

Jie GUO,Danmei XIE(

),Hengliang ZHANG,Wei JIANG,Yan ZHOU

School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China

Download: PDF(716 KB) HTML
Export: BibTeX | EndNote | Reference Manager | ProCite | RefWorks

Abstract

The precise calculation of temperature and thermal stress field of steam turbine rotor under off-design conditions is of paramount significance for safe and economic operation, in which an accurate calculation of heat transfer (HT) coefficient plays a decisive role. HT coefficient changes dramatically along with working conditions. First, a finite element analysis of rotor model, applied with ordinary rotor materials, has been conducted to investigate the temperature and thermal stress difference along with the change of HT coefficient from 20 W/(m²·°C) to 20000 W/(m²·°C). Next, the differentiation between existing empirical formulas has been analyzed from the aspect of physical significance of non-dimension parameters. Finally, a verifying case of the cold startup of a 1000MW unit has been proceeded. The result shows that the accuracy of coefficient calculation when steam parameters are low has a greater influence on that of rotor temperature and thermal stress, which means a precise empirical HT coefficient formula, like the Sarkar formula is strongly recommended. When steam parameters are high and HT coefficient is larger than 10⁴ W/(m²·°C), there will be barely any influence on the calculation of thermal stress. This research plays a constructive role in the calculation and analysis of thermal stress.

Keywords steam turbine rotor thermal stress heat transfer coefficient empirical formula

Corresponding Author(s): Danmei XIE

Online First Date: 04 November 2015 Issue Date: 29 February 2016

Cite this article:

Jie GUO,Danmei XIE,Hengliang ZHANG, et al. Effect of heat transfer coefficient of steam turbine rotor on thermal stress field under off-design condition[J]. Front. Energy, 2016, 10(1): 57-64.

URL:

https://academic.hep.com.cn/fie/EN/10.1007/s11708-015-0385-3
https://academic.hep.com.cn/fie/EN/Y2016/V10/I1/57

Fig.1 Meshing of single stage rotor

Tab.1 Physical parameters of rotor material

Tab.2 HT coefficients in all cases

Fig.2 Results of Cases 1, 2, 3, 4

(a) Temperature-time curves; (b) thermal stress-time curves

Tab.3 Values of maximal temperature and thermal stress of Cases 1 to 4

Fig.3 Results of Cases 5 to 10

(a) Temperature-time curves; (b) thermal stress-time curves

Tab.4 Values of maximal temperature and thermal stress of Cases 5 to 10

Fig.4 1000 MW HP rotor model

Fig.5 Refinement in impeller root

Tab.5 Cases of cold startup

Fig.6 Cold startup curves

Fig.7 HT coefficients by different formula

Fig.8 Temperature distribution at the end of startup (°C)

Fig.9 Thermal stress distribution at the end of startup (MPa)

Fig.10 Temperature-time curves of all cases

Fig.11 Thermal stress-time curves of all cases

Fig.12 Mean error curves

1	Yang Z L, Wang H N, Yang C G. Analysis of 600 MW turbine rotor thermal stress and loss of life. Turbine Technology, 2011(5): 383–385(in Chinese)
2	Yang S M, Tao W Q. Heat Transfer. 4th ed. Beijing: Higher Education Press, 2006 (in Chinese).
3	Zhang H L, Xie D M, Xiong Y H, Sun K F. The research and development of high-quality thermal-stress online monitoring model for 600 MW turbine rotors. In: Proceedings of the CSEE, 2006, 26(1): 21–25
4	Sarkar D, Mukherjee P K, Sen S K. Approximate analysis of steady state heat convection in an induction motor. IEEE Transactions on Energy Conversion, 1993, 8(1): 78–84 https://doi.org/10.1109/60.207409
5	Adinarayana N, Sastri V M K. Estimation of convective heat transfer coefficient in industrial steam turbine. Journal of Pressure Vessel Technology, 1996, 118(2): 247–250 https://doi.org/10.1115/1.2842187
6	Ding Y Y, Zhou H L. Steam Turbine Strength Calculation. Beijing: China Water and Electric Power Press, 1985
7	Liu Y F, Hao R T, Gao J Q. The comparison and application of two common formula of heat transfer coefficient. Turbine Technology, 2007, (2): 97–98, 102 (in Chinese)
8	Qi H T, Hu N S, Zhou Y Y. Application to the calculation formula of the H-exchange coefficient of ALSTHOM. Turbine Technology, 2004, 46(1): 21–22 (in Chinese)
9	Liu S, Zhou Y, Zhang H L, Xie D M. Precision correction for surface heat transfer coefficient of a steam turbine rotor. Thermal Power Generation, 2014, 43(7): 143–147
10	Zhang C, Xu Z L, Liu S, Feng Y X, Yang Y, Zheng L K. Steam turbine rotor thermal stress calculation with thermos-structural coupled model. Journal of Xi’an Jiaotong University, 2014, 48(4): 68–72 (in Chinese)

[1]	R. LALITHA NARAYANA, V. RAMACHANDRA RAJU. Experimental study on performance of passive and active solar stills in Indian coastal climatic condition[J]. Front. Energy, 2020, 14(1): 105-113.
[2]	Himani,Ratna DAHIYA. Condition monitoring of a wind turbine generator using a standalone wind turbine emulator[J]. Front. Energy, 2016, 10(3): 286-297.
[3]	Jinyuan SHI,Zhicheng DENG,Yong WANG,Yu YANG. Structure improvement and strength finite element analysis of VHP welded rotor of 700°C USC steam turbine[J]. Front. Energy, 2016, 10(1): 88-104.
[4]	A. CHITRA,S. HIMAVATHI. A modified neural learning algorithm for online rotor resistance estimation in vector controlled induction motor drives[J]. Front. Energy, 2015, 9(1): 22-30.
[5]	Foued CHABANE,Nesrine HATRAF,Noureddine MOUMMI. Experimental study of heat transfer coefficient with rectangular baffle fin of solar air heater[J]. Front. Energy, 2014, 8(2): 160-172.
[6]	Manli LUO, Jing LIU. Experimental investigation of liquid metal alloy based mini-channel heat exchanger for high power electronic devices[J]. Front Energ, 2013, 7(4): 479-486.
[7]	D. R. BINU BEN JOSE, N. AMMASAI GOUNDEN, Raavi SRI NAGA RAMESH. A unified power electronic controller for wind driven grid connected wound rotor induction generator using line commutated inverter[J]. Front Energ, 2013, 7(1): 39-48.
[8]	K. YAHIA, S. ZOUZOU, F. BENCHABANE. Induction motors variable speed drives diagnosis through rotor resistance monitoring[J]. Front Energ, 2012, 6(4): 420-426.
[9]	Youmin HOU, Danmei XIE, Wangfan LI, Xinggang YU, Yang SHI, Hanshi QIN. Numerical simulation of a new hollow stationary dehumidity blade in last stage of steam turbine[J]. Front Energ, 2011, 5(3): 288-296.
[10]	Dieter BOHN , Robert KREWINKEL , Shuqing TIAN , . Cooling performance of grid-sheets for highly loaded ultra-supercritical steam turbines[J]. Front. Energy, 2009, 3(3): 313-320.
[11]	Michal HOZNEDL , Ladislav TAJC , Jaroslav KREJCIK , Lukas BEDNAR , Kamil SEDLAK , Jiri LINHART , . Exhaust hood for steam turbines-single-flow arrangement[J]. Front. Energy, 2009, 3(3): 321-329.
[12]	SHI Jinyuan. Reliability design method for steam turbine blades[J]. Front. Energy, 2008, 2(4): 363-368.
[13]	JIANG Jian, LIU Bo, WANG Yangang, NAN Xiangyi. Numerical simulation of three-dimensional turbulent flow in multistage axial compressor blade row[J]. Front. Energy, 2008, 2(3): 320-325.
[14]	SHI Jinyuan, DENG Zhicheng, YANG Yu, JUN Ganwen. Heat transfer coefficient of wheel rim of large capacity steam turbines[J]. Front. Energy, 2008, 2(1): 20-24.

Viewed

Full text

Abstract

Cited

Shared

Discussed