Gas-steam combined cycle heat supply unit shaft seal steam supply system and running method

Abstract

The invention discloses a gas-steam combined cycle heat supply unit shaft seal steam supply system and a running method. The gas-steam combined cycle heat supply unit shaft seal steam supply system comprises a high-pressure cylinder, an intermediate-pressure cylinder, a low-pressure cylinder, a starting boiler and an auxiliary steam header. Steam is supplied to the steam inlet sides of the high-pressure cylinder, the intermediate-pressure cylinder and the low-pressure cylinder through a shaft seal steam mother pipe, a temperature measuring point T2 is arranged on the shaft seal steam mother pipe, the high-pressure cylinder, the intermediate-pressure cylinder and the low-pressure cylinder form a shaft seal cavity, residual steam enters a shaft seal steam return mother pipe through steam return pipelines after the shaft seal cavity completes sealing, a steam return manual regulating valve is arranged on each steam return pipeline, and steam of the shaft seal steam return mother pipe is sent to a shaft seal heater. A steam source on the auxiliary steam header is respectively supplied by a reheating cold section steam supply auxiliary steam header, a high-pressure main steam drain supply auxiliary steam header and a starting boiler steam supply auxiliary steam header. The method that multiple heat sources are supplied to the auxiliary steam header is adopted, the temperature and pressure of steam supplied to a shaft seal by the auxiliary steam header are guaranteed, and the running safety and stability of the shaft seal system are improved.

Description

technical field [0001] The invention relates to the technical field of a shaft seal steam supply system, in particular to a shaft seal steam supply system and an operating method of a gas-steam combined cycle heating unit. Background technique [0002] Gas-steam combined cycle units have the advantages of high power generation efficiency, good environmental performance, fast start-up, small footprint, and high degree of automation. They have been widely used around the world to provide various types of power and energy. Most of them are used for power generation, and some are used for cogeneration of heat and power or cogeneration of cooling, heating and power, providing production and domestic heat and cooling while supplying power. [0003] The shaft seal system is an important part of the steam turbine. The function of the high-pressure shaft seal is to prevent steam from leaking out of the cylinder to ensure high efficiency of the steam turbine. The function of the low-p...

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Problems solved by technology

[0004] For gas-steam combined cycle heating units, due to real-time changes in heat supply, some operating parameters of the unit will be affected, thereby affecting the safety and stability of the shaft seal system.

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