Cover structure for improving cooling efficiency of horizontal gas film on downstream of open slotted hole

Abstract

The invention relates to a cover structure for improving the cooling efficiency of a horizontal gas film on the downstream of an open slotted hole. The cover structure comprises a gas film hole, a horizontal open slot, a wall, protrusions and caps. The gas film hole is formed in the upstream area of the wall. The horizontal open slot is formed in an air outlet of the gas film hole. The protrusions are arranged in the downstream area of the wall and are distributed with the central line of the wall passing through the center of the air outlet of the gas film hole as the axis of symmetry. The face, facing the air outlet of the gas film hole, of each protrusion is a protrusion air inlet, and the opposite is a protrusion air outlet. The ratio of the length of each protrusion air inlet to the aperture of the gas film hole ranges from 2.0 to 5.0, and the length of each protrusion air inlet is 1.5-5.0 times that of the corresponding protrusion air outlet. The distance from each protrusion air inlet to the center of the air outlet of the gas film hole is 10-30 times the aperture of the gas film hole. The ratio of the height of the protrusions to the aperture of the gas film hole ranges from 0.25 to 3.0. The cover structure is characterized by further comprising the caps which cover the protrusions; the two sides of each cap are fixedly connected with the top of the corresponding protrusion; and the thickness of the caps is not greater than one fifth of the aperture of the gas film hole.

Description

technical field [0001] The invention relates to the technical field of blade cooling inside a gas turbine, in particular to a cover structure for improving the cooling efficiency of the transverse air film downstream of a slotted hole. Background technique [0002] As an important power device, gas turbine is widely used in aerospace, chemical industry, vehicle, power generation and other fields. The development of gas turbines marks a country's technological level, military strength and comprehensive strength. The thermal efficiency and output power of the gas turbine are mainly affected by the gas temperature. At this stage, the initial temperature of the inlet of the gas turbine is mainly increased by continuously developing high-temperature resistant materials and adopting cooling technology. However, due to the limitation of the development of high-temperature-resistant materials, effective cooling methods must be used to prevent the hot-end parts of the gas turbine fr...

AI Technical Summary

Problems solved by technology

The Chinese patent (Patent No. 201010106756.6) proposes a structure to improve the efficiency of film cooling of discrete holes. This structure does not take into account the superimposed effect of film cooling on the wall surface by transverse grooves. The downstream protrusion is not only integrated with the wall surface, but also At the same time, it is close to the gas film hole, which hinders the flow of cooling gas to the downstream wall surface, and the protrusion raises the cooling gas, exposing the wall surface within a certain range near the protrusion to high-temperature gas, reducing the protective effect of the cooling gas film on the wall surface

The applicant's previous patent application (201520094208.4) proposed a structure to improve the film cooling efficiency of the downstream wall of the slotted film hole. The structure has transverse grooves and protrusions, but the patent still has the following shortcomings: The cooling air that is far away from the wall cannot be fully collected by the bulge, and this part of the cooling air rises when it encounters the bulge, which reduces the cooling efficiency of the wall near the bulge

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