Cooling method and structure of cantilever type supercritical carbon dioxide turbine

Abstract

The invention relates to the field of turbines, in particular to a cooling method and structure of a cantilever type supercritical carbon dioxide turbine, main sealing gas for dry gas sealing is injected from a first gas channel on a dry gas sealing shell, and the sealing gas is cooling gas which sequentially flows into the shell along a second gas channel and a first gap between a high-speed shaft and a splitting ring; and one path of cooling gas is exhausted to an exhaust flow channel in the shell through an exhaust hole of a baffle, the other path of cooling air is exhausted to the exhaust flow channel in the shell through a second gap formed by the baffle and a turbine disc, in addition, after the splitting ring and a middle shell are split into two parts, the radial temperature gradient on each part is reduced, therefore, the temperature stress on each part is reduced, the turbine can be better cooled, and the strength reliability of a unit is ensured.

Description

technical field [0001] The invention relates to the field of turbines, in particular to a cooling method and structure of a cantilever type supercritical carbon dioxide turbine. Background technique [0002] The supercritical carbon dioxide turbine uses high-temperature (450-780°C) and high-pressure (15-25MPa) supercritical carbon dioxide as a working medium, expands when flowing through the nozzle ring and turbine disk inside the shell, converts thermodynamic energy into gas kinetic energy, and drives The turbine disk rotates, and the turbine disk is connected to the high-speed rotor, which is directly driven or driven by a gear to drive the generator to generate electricity. The pressure level inside the housing is high, requiring a dry gas seal to prevent a large amount of carbon dioxide from leaking through the gap between the housing and the main shaft. [0003] The dry gas seal is also composed of dynamic and static rings and dynamic and static ring cages. There are ...

AI Technical Summary

Problems solved by technology

There are rubber sealing rings installed between the static ring retainer and the shell of the dry gas seal, and between the dynamic ring retainer and the main shaft. As high as 450-780°C, it is necessary to cool the shell and rotor, which will cause a large temperature change from 450-780°C to 175°C on the shell and rotor. The size of the cantilever supercritical carbon dioxide turbine is small , the space for temperature change on the shell and rotor is limited, so the temperature change will be very severe, that is, the temperature gradient is large, resulting in large temperature stress, which threatens the strength of the shell and rotor

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