Sealing technique for restraining leakage flow loss of back cavity of centripetal turbine

Abstract

The invention discloses a sealing technique for restraining the leakage flow loss of a back cavity of a centripetal turbine. According to the specific structure, a leakage flow sealing structure is arranged on a case in a junction area of a main passage of the centripetal turbine and the back cavity of an impeller, wherein the sealing structure can be in a rectangular protrusion form or a trapezoidal protrusion form or is a comb tooth sealing structure, a brush-type sealing structure or the like and can be made from soft metal, graphite or other materials so as to reduce abrasion to the impeller; the sealing structure can be disassembled from the case so as to be replaced after being abraded; and the sealing structure can be applied to centripetal turbines in multiple fields such as aerospace, transportation and compressed air energy storage and is particularly suitable for high-pressure centripetal turbines. The sealing structure has the advantages that leakage of working medium gas to the back cavity of the impeller from an impeller passage and leakage of sealing gas in the back cavity of the impeller to the impeller passage are effectively controlled, so that the leakage flow loss of the back cavity of the impeller of the centripetal turbine is effectively controlled, the pneumatic efficiency of the centripetal turbine is improved, the energy utilization rate is increased, and maintenance and replacement are facilitated.

Description

technical field [0001] The invention relates to the technical field of centripetal turbines in turbomachinery, and relates to a technology for controlling internal leakage flow loss of a centripetal turbine, in particular to a sealing technology for suppressing leakage loss in the back cavity of a centripetal turbine. Background technique [0002] The impeller machinery is widely used and has a variety of structural types, providing electricity and power for industrial production and public life in various fields. As a type of impeller machinery, the centripetal turbine has the characteristics of simple structure, low cost, and high single-stage pressure ratio, and has been widely used. In order to make a unit volume of equipment output as much mechanical energy as possible under the same thermal parameters, it is necessary to improve the efficiency of the centripetal turbine. Such as Figure 1~3 As shown, due to the rotation of the impeller 10 of the centripetal turbine, t...

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Problems solved by technology

However, this method does not take into account the leakage of the working medium in the back cavity 50 of the upstream wheel disc of the grate tooth seal structure 60 to the main channel of the impeller driven by the centrifugal force of the high-speed rotation of the impeller, and the relationship between the working medium in the main channel of the impeller and the high-entropy working medium in this area. Flow losses due to mass and energy exchange of

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