Design And Practice On Switch Control Of Steam Turbine Operation Modes For Gas-steam Combined-cycle Cogeneration Unit

The gas-steam combined-cycle generation is an advanced technology. It has the advantages of little pollution, high thermal efficiency, good regulation of peak power, short period of installment, and small investment, thus is widely accepted around the world.Gas-steam combined-cycle cogeneration units,while improving the environment to achieve the energy cascade utilization, is the city heat supply project development, construction low carbon ecological areas, the inevitable outcome of the energy system has a good application prospect. NCB type unit is for large cogeneration project and development of new models, is in the condensing steam extraction on the basis of the heat pump units, in line with increasing unit heating capacity, reduce unit cold source loss, improve the thermal efficiency of the power plant and the development of new models, has significant economic benefits.The gas-steam combined-cycle cogeneration "two drag one" units of Datang International Beijing Gaojing power plant, including two PG9371FB heavy-duty gas turbine generator set of GE, a 9FB steam turbine generator set of The Harbin steam turbine factory, the steam turbine unit is independent research and development of the first batch of NCB, steam type cogeneration units.This paper based on the commissioning of the unit, the control principle and control systems of combined-cycle are discussed in this paper, and the cogeneration control object to the study on the control of steam turbine, analyses the combined-cycle cogeneration NCB type steam turbine structure features and operation principle, puts forward the key technology of this type of unit and control difficulty, is based on the problems, combined with the unit steam turbine research analysis,Form a set of relatively complete steam turbine operation modes conversion control scheme, and in winter heating period in system debugging and practice inspection, make the control scheme for heat level control requirements, improve the efficiency of heating unit and the security and stability, reduce caused by non stop to unit test.