Nine-stage regenerative extraction steam system of 1000MW thermal power generating unit turbine

Abstract

The invention discloses a nine-stage regenerative extraction steam system of a 1000MW thermal power generating unit turbine. The nine-stage regenerative extraction steam system comprises a condenser, a turbine low-pressure cylinder, a turbine intermediate-pressure cylinder, a turbine high-pressure cylinder and a boiler. The turbine high-pressure cylinder is correspondingly connected with a first high-pressure heater and a second high-pressure heater. The turbine intermediate-pressure cylinder is correspondingly connected with a third high-pressure heater, a deaerator and a fifth low-pressure heater. The turbine low-pressure cylinder is correspondingly connected with a sixth low-pressure heater, a seventh low-pressure heater, an eighth low-pressure heater and a ninth low-pressure heater. Low-pressure drainage pumps are arranged on the seventh low-pressure heater. The eighth low-pressure heater and the ninth low-pressure heater directly drain water to the condenser through an eighth drainage pipe and a ninth drainage pipe respectively. The nine-stage regenerative extraction steam system of the 1000MW thermal power generating unit turbine has the advantages that the number of regeneration stages is increased by one, and therefore thermal efficiency is improved; the problem that because steam pressure is low, unsmooth drainage is probably caused in the low-load operation process is solved; although the number of devices is increased, operating cost is reduced, and accordingly the nine-stage regenerative extraction steam system is more economical.

Description

technical field [0001] The invention relates to the technical field of thermal power units, in particular to a 9-stage regenerative steam extraction system for a steam turbine of a 1000MW thermal power unit. Background technique [0002] Theoretically, the more stages of feedwater reheating, the closer the thermal cycle process of the steam turbine is to the Carnot cycle, and the higher the efficiency of the steam thermal cycle, but when the heating stages increase, the growth of thermal efficiency gradually slows down, and the relative benefits are not great. more, and the operation is more complicated. [0003] At present, the domestic 1000MW ultra-supercritical units all use four-cylinder four-exhaust steam units, the steam turbines of air-cooled units usually use 7-stage regenerative steam extraction, and the steam turbines of wet-cooled units usually use 8-stage regenerative steam extraction. [0004] If you try to simply increase the 8-stage regenerative steam extract...

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Problems solved by technology

[0004] If you try to simply increase the 8-stage regenerative steam extraction system of the steam turbine to a 9-stage regenerative steam extraction system, you will face a problem: the last two stages of the 8-stage regenerative steam extraction system originally have low steam pressure. During low-load operation, there may be poor water drainage, and this problem will become more prominent in the 9-stage regenerative steam extraction system

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