Experimental Study on Thermodynamic Characteristics of Optimized 1 000 MW Steam Turbines with Variable Back Pressure

doi:10.11930/j.issn.1004-9649.201711159

Abstract

Abstract: The variations of steam turbine operating back pressure will impact not only the thermal performance, but also the operation efficiency of the LP casing greatly because of the change of the exhaust volume flow. Through the back pressure variation test under different loads, the thermodynamic characteristics subject to the back pressure changes are studied for the Dongfang optimized 1000-MW steam turbine, from which the influencing formulas of the back pressure on the output and the heat rate are obtained as well as the relationship curve between the LP casing efficiency and the exhaust volume flow. The operating characteristics of the LP casings are analyzed, and the operation back pressure limits of the turbine are estimated. At last, suggestions are put forward on improving the operation efficiency of the LP casings. The test results and analysis show that the turbine equipped with 1 200-mm last stage blade has higher efficiency and better working characteristics of the LP casings in the back pressure variation, while the economic performance of the unit will be deteriorated due to the deviation between the actual working characteristics and the design expectations of the LP casings.

Key words: 1 000-MW unit, steam turbine, back pressure, efficiency of LP casing, exhaust volume flow

CLC Number:

TK267

BAO Jinsong, QIN Pan, LOU Kewei, ZHU Meifang, WU Ruikang, LI Jun. Experimental Study on Thermodynamic Characteristics of Optimized 1 000 MW Steam Turbines with Variable Back Pressure[J]. Electric Power, 2018, 51(4): 81-88.

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URL: https://www.electricpower.com.cn/EN/10.11930/j.issn.1004-9649.201711159

https://www.electricpower.com.cn/EN/Y2018/V51/I4/81

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