Dual-outlet pre-swirl cooling system and method based on periodic oscillating jet

Abstract

This invention discloses a dual-outlet pre-swirl cooling system and method based on periodic oscillating jets, relating to the field of pre-swirl cooling in gas turbine secondary air systems. The system includes, in sequence, an inlet chamber, a jet oscillating pre-swirl nozzle, a stationary pre-swirl chamber, a dynamic pre-swirl chamber, a receiving port, a co-rotating chamber, and an air supply outlet. Each of the stationary pre-swirl chamber, dynamic pre-swirl chamber, receiving port, co-rotating chamber, and air supply outlet comprises inner and outer parts. The jet oscillating pre-swirl nozzle includes an inlet and two outlets, inner and outer. Airflow from the inlet chamber is split into two streams by the jet oscillating pre-swirl cooling nozzle, flowing into the inner and outer stationary pre-swirl chambers respectively, and then into the co-rotating chamber through the receiving port. Compared to traditional pre-swirl cooling nozzles, this invention can apply oscillating characteristics to the airflow at the nozzle outlet and split it into two streams that enter the blades respectively, enhancing convective heat transfer between the cool air and the blades, which is beneficial to improving the cooling performance of the pre-swirl cooling system.

Description

Technical Field

[0001] This invention relates to the field of pre-swirl cooling for gas turbine secondary air systems, and specifically to a dual-outlet pre-swirl cooling system and method based on periodic oscillating jets. Background Technology

[0002] One of the key technologies for improving gas turbine performance is increasing the inlet temperature of the gas turbine. However, the continuously rising inlet temperature of the gas turbine leads to a continuous deterioration in the operating conditions of its components. Efficient cooling technology can ensure the stable operation of these components, extend their lifespan, and reduce costs, while also improving the engine's thrust-to-weight ratio and efficiency. A crucial component of the gas turbine system is pre-swirl cooling technology. This technology primarily reduces the relative total temperature of the cooling airflow by introducing an initial velocity along the circumferential direction of the turbine blades to the cool air exiting the compressor through pre-swirl nozzles. The pre-swirl cooling system includes components such as an inlet chamber, pre-swirl nozzles, a pre-swirl chamber, a receiving orifice, a co-rotation chamber, and an air supply outlet. Traditional pre-swirl cooling systems often use cylindrical tubes or converging nozzles for cooling. While these effectively provide pre-swirl, the cool air in such systems lacks oscillatory characteristics and only has one set of pre-swirl chambers, receiving orifices, and co-rotation chambers, resulting in some mixing losses in the airflow. A pre-swirl cooling structure employing a jet oscillation pre-swirl nozzle, combined with two sets of pre-swirl chambers, receiving orifices, and a co-rotation chamber, can divide the nozzle outlet airflow into two streams with oscillating characteristics. These streams flow into the two sets of pre-swirl chambers, receiving orifices, and co-rotation chambers respectively, and finally flow into different cooling channels of the blade through two sets of air supply outlets for cooling. This can reduce mixing losses within the chambers to a certain extent and avoid uneven cooling caused by a single airflow during blade cooling. Simultaneously, the oscillating characteristics of the cold airflow can increase its convective heat transfer coefficient with the blade wall, improving cooling performance. The dual-channel cooling structure inside the blade results in a more uniform temperature distribution. Summary of the Invention

[0003] This invention provides a dual-outlet pre-swirl cooling system and method based on periodic oscillating jets. To improve the cooling characteristics of the system and reduce the mixing loss of cold air in the chamber, a jet oscillation structure is used as the pre-swirl nozzle, and two sets of pre-swirl chambers and a co-rotation chamber are used to receive the airflow from the jet oscillation nozzle outlet.

[0004] A dual-outlet pre-swirl cooling system based on periodic oscillating jets, characterized in that it sequentially comprises an air inlet chamber, a jet oscillating pre-swirl nozzle, a static pre-swirl chamber, a dynamic pre-swirl chamber, a receiving port, and a co-rotation chamber; the jet oscillating pre-swirl nozzle includes an airflow inlet and two airflow outlets (inner and outer); the static pre-swirl chamber includes an inner static pre-swirl chamber and an outer static pre-swirl chamber; the dynamic pre-swirl chamber includes an inner dynamic pre-swirl chamber and an outer dynamic pre-swirl chamber; the receiving port is divided into an inner ring receiving port and an outer ring receiving port. The co-rotation cavity includes two chambers: a co-rotation inner chamber and a co-rotation outer chamber, with air supply outlets distributed in the co-rotation inner and outer chambers. The airflow inlet of the jet oscillation pre-rotation nozzle is connected to the air inlet chamber. The airflow inner outlet of the jet oscillation pre-rotation nozzle passes sequentially through the inner static pre-rotation chamber, the inner dynamic pre-rotation chamber, and the inner ring receiving hole, and connects to the co-rotation inner chamber to form an inner chamber. The airflow outer outlet of the jet oscillation pre-rotation nozzle passes sequentially through the outer static pre-rotation chamber, the outer dynamic pre-rotation chamber, and the outer ring receiving hole, and connects to the co-rotation outer chamber to form an outer chamber.

[0005] The working method of the dual-outlet pre-swirl cooling system based on periodic oscillating jet includes the following process: the airflow from the inlet cavity passes through the jet oscillating pre-swirl nozzle and is divided into two streams with a certain pre-swirl, flowing into the inner static pre-swirl cavity and the outer static pre-swirl cavity respectively; the inner static pre-swirl cavity and the outer static pre-swirl cavity are connected to the inner dynamic pre-swirl cavity and the outer dynamic pre-swirl cavity respectively; after the airflow flows out from the inner dynamic pre-swirl cavity and the outer dynamic pre-swirl cavity, it flows into the co-rotating inner cavity and the co-rotating outer cavity through the inner ring receiving hole and the outer ring receiving hole respectively, and then flows into different cooling channels of the turbine blades of the dual-channel cooling structure respectively;

[0006] After the airflow flows from the intake chamber into the airflow inlet of the jet oscillating pre-swirl nozzle, it flows alternately through the left and right flow channels, generating periodic oscillating jets at the two airflow outlets inside and outside the jet oscillating pre-swirl nozzle. As a result, the inner and outer static pre-swirl chambers receive cooling airflow with oscillating characteristics.

[0007] This invention proposes a dual-outlet pre-swirl cooling system based on periodic oscillating jets. Compared to traditional pre-swirl cooling systems, this system employs a jet oscillating pre-swirl nozzle paired with two sets of pre-swirl chambers, receiving orifices, and a co-rotating chamber. This structure divides the nozzle outlet airflow into two streams with oscillating characteristics, which flow into the two sets of pre-swirl chambers, receiving orifices, and co-rotating chambers respectively. Finally, the airflow flows into different cooling channels of the blade through two sets of air supply outlets for cooling. This reduces mixing losses within the chambers to some extent. Simultaneously, the oscillating characteristics of the cold airflow increase its convective heat transfer coefficient with the blade wall. The two streams of cold air enter the blade's internal dual-channel cooling system separately, improving cooling performance. Furthermore, the inner and outer chambers are independent and do not interfere with each other. Attached Figure Description

[0008] Figure 1 This is a slant view of the flow path of the pre-swirl system;

[0009] Figure 2 This is the front view of the flow channel of the pre-swirl system;

[0010] Figure 3 This is a cross-sectional view of the cover plate;

[0011] Figure 4 This is a cross-sectional view of the jet oscillation nozzle flow channel;

[0012] Figure 5 This is a schematic diagram of the turbine blade cooling structure;

[0013] The following are the labels in the diagram: 1. Inlet chamber; 2. Jet oscillation pre-swirl nozzle; 3. Static pre-swirl chamber; 4. Dynamic pre-swirl chamber; 5. Receiver hole; 6. Co-rotation chamber; 7. Cover plate; 8. Airflow inlet; 9. Airflow outlet. Detailed Implementation

[0014] The following is in conjunction with the appendix Figures 1 to 5 Detailed description of the airflow process in this invention:

[0015] The airflow from the inlet chamber 1 is split into two streams by the jet oscillation pre-swirl nozzle 2 and flows into the inner static pre-swirl chamber and the outer static pre-swirl chamber respectively. The inner static pre-swirl chamber and the outer static pre-swirl chamber are connected to the inner dynamic pre-swirl chamber and the outer dynamic pre-swirl chamber respectively. After the airflow exits from the inner dynamic pre-swirl chamber and the outer dynamic pre-swirl chamber, it flows into the co-rotating inner cavity and the co-rotating outer cavity through the inner ring receiving hole and the outer ring receiving hole respectively, and then flows into the air supply hole. Figure 5 The turbine blade cooling channel shown.

[0016] Airflow enters from intake chamber 1 as follows Figure 4 After the jet oscillation structure shown in the diagram enters, it flows alternately through the left and right channels. Periodic oscillating jets are generated at the two outlets of the jet oscillation pre-swirl nozzle, thus causing the inner static pre-swirl chamber and the outer static pre-swirl chamber to receive cooling airflow with oscillating characteristics.

[0017] like Figure 5 The turbine blades shown have a dual-channel cooling structure inside, which can avoid problems such as excessively high cold air temperature at the end of the channel caused by single-channel cooling, thus improving cooling performance.

Claims

1. A dual-outlet pre-swirl cooling system based on periodic oscillating jets, characterized in that: The system comprises, in sequence, an inlet chamber (1), a jet oscillation pre-swirl nozzle (2), a static pre-swirl chamber (3), a dynamic pre-swirl chamber (4), a receiving port (5), and a co-rotation chamber (6); the jet oscillation pre-swirl nozzle (2) includes an airflow inlet (8) and two airflow outlets (9); the static pre-swirl chamber includes an inner static pre-swirl chamber and an outer static pre-swirl chamber; the dynamic pre-swirl chamber includes an inner dynamic pre-swirl chamber and an outer dynamic pre-swirl chamber; the receiving port is divided into an inner ring receiving port and an outer ring receiving port; the co-rotation chamber includes a co-rotation chamber. The jet oscillating pre-swirl nozzle (2) has two chambers: an inner chamber and a co-rotating outer chamber. The co-rotating inner chamber and the co-rotating outer chamber are equipped with air supply outlets. The airflow inlet (8) of the jet oscillating pre-swirl nozzle (2) is connected to the air inlet chamber (1). The airflow outlet of the jet oscillating pre-swirl nozzle (2) passes through the inner static pre-swirl chamber, the inner dynamic pre-swirl chamber, and the inner ring receiving hole in sequence and is connected to the co-rotating inner chamber to form an inner chamber. The airflow outlet of the jet oscillating pre-swirl nozzle (2) passes through the outer static pre-swirl chamber, the outer dynamic pre-swirl chamber, and the outer ring receiving hole in sequence and is connected to the co-rotating outer chamber to form an outer chamber.

2. The dual-outlet pre-swirl cooling system based on periodic oscillating jets according to claim 1, characterized in that: The aforementioned inner and outer chambers are independent and do not interfere with each other.

3. The operating method of the dual-outlet pre-swirl cooling system based on periodic oscillating jets according to claim 1 includes the following processes: After passing through the jet oscillation pre-swirl nozzle (2), the airflow from the intake chamber (1) is divided into two streams with a certain pre-swirl and flows into the inner static pre-swirl chamber and the outer static pre-swirl chamber respectively. The inner static pre-swirl chamber and the outer static pre-swirl chamber are connected to the inner dynamic pre-swirl chamber and the outer dynamic pre-swirl chamber respectively. After the airflow flows out from the inner dynamic pre-swirl chamber and the outer dynamic pre-swirl chamber, it flows into the co-rotating inner cavity and the co-rotating outer cavity through the inner ring receiving hole and the outer ring receiving hole respectively, and then flows into different cooling channels of the turbine blade with a dual-channel cooling structure. After the airflow flows from the inlet chamber (1) into the airflow inlet (8) of the jet oscillation pre-swirl nozzle (2), it flows alternately through the left and right channels, generating periodic oscillating jets at the two airflow outlets (9) inside and outside the jet oscillation pre-swirl nozzle. As a result, the inner static pre-swirl chamber and the outer static pre-swirl chamber receive cooling airflow with oscillating characteristics.

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