System and method for starting double-reheat stream turbine

Abstract

The invention provides a system and method for starting a double-reheat stream turbine. The system comprises a boiler, a super-high-pressure cylinder, a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder, a primary reheater, a secondary reheater, a condenser, a super-high-pressure main throttle valve, a super-high-pressure control valve, a super-high-pressure exhaust check valve, a high-pressure main throttle valve, a high-pressure control valve, a high-pressure exhaust check valve, an intermediate-pressure main throttle valve and an intermediate-pressure control valve. When the exhaust temperature of the super-high-pressure cylinder is too high, the opening degree of the high-pressure control valve and the opening degree of the intermediate-pressure control valve are reduced, and the opening degree of the super-high-pressure control valve is increased; when the exhaust temperature of the high-pressure cylinder is too high, the opening degree of the intermediate-pressure control valve is reduced, and the opening degree of the super-high-pressure control valve and the opening degree of the high-pressure control valve are increased. The intake steam flow distribution among the super-high-pressure cylinder, the high-pressure cylinder and the intermediate-pressure cylinder is adjusted by controlling the opening degree of the super-high-pressure control valve, the opening degree of the high-pressure control valve and the opening degree of the intermediate-pressure control valve so that the super-high-pressure cylinder and the high-pressure cylinder can be prevented from being overheated, and therefore the double-reheat stream turbine has the starting advantages of flexibility, rapidness and a low service life loss.

Description

technical field [0001] The invention relates to a steam turbine, in particular to a start-up system and a start-up method of a double reheat steam turbine. Background technique [0002] The steam turbine generator set is one of the key power equipment in the construction of the power station. It is an energy conversion equipment used to convert thermal energy into mechanical energy and then convert mechanical energy into electrical energy. When the steam turbine generating set is generating electricity, the high-temperature and high-pressure steam generated by the boiler passes through the steam turbine, thereby converting the thermal energy and pressure potential energy of the steam into the mechanical energy of the steam turbine, and then drives the rotor output shaft of the steam turbine to rotate and do work; the mechanical energy of the steam turbine passes through the output shaft of the steam turbine rotor Passed to the generator, which converts mechanical energy into...

AI Technical Summary

Problems solved by technology

[0004] Compared with the original one-time reheating cycle, after adopting the second-time reheating cycle, one more stage of reheater and one reheating cylinder are added. Great changes have taken place. The exhaust steam temperature of the ultra-high pressure cylinder and high pressure cylinder has been greatly increased. Therefore, the original start-up method of the once-reheated steam turbine cannot...

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