A supercritical carbon dioxide turbine dry gas seal failure protection device and method

Abstract

The invention provides a supercritical carbon dioxide turbine dry gas seal failure protection device and method. The protection device includes: a cylinder cooling structure for cooling the cylinder block in the vicinity of the dry gas seal in the turbine cylinder; The cylinder cooling structure provides a cooling branch of carbon dioxide cooling gas, and at the same time has a protection branch supplying carbon dioxide protection gas to the area near the turbine bearing. Methods The interlocking control of the wall temperature exceeding the limit with the shutdown of the turbine and the introduction of carbon dioxide cooling gas is used to cool the cylinder block in the vicinity of the dry gas seal in the turbine cylinder through an external carbon dioxide cooling gas; And the introduction of carbon dioxide protective gas to start the interlock control, through the external carbon dioxide protective gas to protect the turbine bearing when the dry gas seal fails. The invention ensures that the dry gas seal is not damaged by high temperature, and can also prevent the high-temperature gas leaked after the turbine dry gas seal is realized from igniting the lubricating oil at the bearing.

Description

technical field [0001] The invention relates to the technical field of advanced turbine equipment, more specifically, to a supercritical carbon dioxide turbine dry gas seal failure protection device and method. Background technique [0002] Supercritical carbon dioxide power conversion technology has technical advantages such as system simplification, high efficiency, small size, and easy realization of module construction. The supercritical carbon dioxide turbine is one of the core equipment of the system. The obvious difference between this turbine and conventional steam turbines is that The working medium of parallel operation is high temperature and high pressure carbon dioxide, and the outlet pressure is high. [0003] The shaft end seal of supercritical carbon dioxide turbine adopts dry gas seal, and the bearing adopts sliding bearing, which is the technical solution adopted by supercritical carbon dioxide turbine at present. However, since the existing dry gas seals ...

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Problems solved by technology

However, since the existing dry gas seals at this stage are mainly for medium and low temperature application scenarios, the sealing rings of dry gas seals are usually made of rubber, which cannot meet the requirements of working conditions with temperatures above 300°C. The temperature of the cylinder at the air-tight structure drops below 300°C

The cooling structure of the turbine cylinder still needs to be continuously cooled when the turbine is shut down. If the cooling fails, the dry gas seal will be damaged

In addition, the wear of the dry gas seal end face and the falling of foreign objects from the outside may lead to damage to the dry gas seal, cooling failure or other causes of damage to the dry gas seal will lead to the failure of the turbine end seal, and the high temperature and high pressure carbon dioxide in the turbine will be discharged to On site, the lubricating oil in the turbine bearing box may be ignited, endangering site safety

[0004] At present, the supercritical carbon dioxide turbine is still in the research and development stage, and there is no protection facility for shutting down the turbine when the dry gas seal of the supercritical carbon dioxide turbine fails. The relevant protection methods are very important for the performance test of the supercritical carbon dioxide turbine.

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