GE9F Gas-steam Combined Cycle Unit With Peaking Capacity Start-up Process And Variable Operating Characteristic Analysis

Recent years, environmental problems has increasingly become a severe issue to constrain China’s economic development, as a consequence, new clean energy alternative to traditional energy sources has become an inevitable trend, gas turbine power generation technology which represented by large gas-steam combined cycle has widespread attention. What is more, with increasing number of GE 9F gas turbine units put into production in commission, the study of 9F unit has been more extensive, whereas the study of start-up and peaking characteristics was rare. This essay sought to improve economic and safety of gas-steam combined cycle operation through analyzing the characteristics of gas-steam combined cycle in start-up process and peaking load regulation.This essay elaborated starting progress and operating mode alteration progress of cogenerated gas turbine with CE 9F, after that, made an analysis to its cogeneration thermodynamic model and efficiency calculation model, which is built in this project. Individually this project introduced the field data measurement and collection during the unit starting and operating progress, the thermodynamic efficiency calculation of compressor, gas turbine and their cogeneration, the factors affecting the efficiency and the analysis of running performance in different running stage.Through the analysis of GT&ST cogeneration running mode, the comparison of running performance of units in winter and summer, or in cold start or warm start had been well analyzed. Thus, as a conclusion, the compressor efficiency in summer is higher than the one in winter while the cogeneration efficiency in winter is higher than the one in summer. Besides, with low load, the cogeneration efficiency in warm mode is higher the one in cold mode. In the aspect of emission analysis, the running performance such as NOx emission met its highest value in the intermediate load of units, SO2 emission reaches its peak at the initial stage of synchronization etc. can also been learned from this essay.Meanwhile, from the experiment about control logic alternation, auxiliary system alternation, low load warm up methods, reliability upgrading etc., the methods of improving gas turbine cogeneration starting progress had been achieved. These methods concludes:improving safety of the units starting and operation mode alternation progress by ’P4 package rebuild’ applying compressor blade wash to improve its running efficiency; modifying the fuel gas heater running time and adopting the reversed casing warm up at the initial stage to increase the starting speed; optimizing the gas turbine IGV control to eliminate the overheat problem in some of the load situations. With the application of these advanced cases, the units starting safety and efficiency had been significantly improved.