CN204692189U - A kind of return channel with deviated splitter vane - Google Patents

Abstract

The utility model discloses a reflux device with long and short blades. The friction loss of the gas in the reflux device is very large, sometimes reaching 6% to 8% of the energy of the stage, which has a great impact on the performance of the entire compressor stage; and the airflow from the outlet of the reflux device can directly affect the performance of the next stage impeller. Therefore, it is necessary to improve the flow of gas flow in the reflux device. The utility model includes a chassis and long blades and short blades welded on the chassis; a plurality of long blades are evenly distributed along the circumference of the chassis, and short blades are arranged between two adjacent long blades; both the long blades and the short blades are arc-shaped, And the arc length of the short blade is 1/3~1/2 of the long blade; the distance ratio between the short blade and two adjacent long blades is 5~8:9, and all the short blades are evenly distributed along the circumference of the chassis. The utility model can ensure the safe and stable operation of the model stage of the centrifugal compressor under the working condition of small flow, avoid the unstable phenomena such as secondary reflux inside the reflux device, and enhance the stability of operation.

Description

A reflux device with long and short blades

technical field

The utility model belongs to the technical field of general equipment, in particular to a reflux device with long and short blades.

Background technique

Centrifugal compressors are mainly composed of impellers, diffusers and reflux devices, and their design level will directly determine the performance of the compressor. The impeller is the rotor, which converts the mechanical energy or electrical energy of the gas into the kinetic energy and potential energy of the gas by continuously driving the gas to rotate; direction into the next stage impeller. In the reflux cascade, the flow velocity has a large gradient, which is a typical unstable and large separation flow. There is an obvious secondary flow vortex on the flow surface, and it experiences the process of primary, development and dissipation along the flow direction. The air flow at the outlet of the return cascade is not purely radial, and the flow has strong inhomogeneity. Studies have shown that the friction loss of gas in the reflux device is very large, sometimes reaching 6%-8% of the stage energy, which has a great impact on the performance of the entire compressor stage. And the air flow from the outlet of the reflux device can directly affect the performance of the next stage impeller, so it is necessary to improve the flow of the air flow in the reflux device. Many scholars have conducted more detailed research on the aerodynamic performance of the single-stage centrifugal compressor impeller, but less research has been done on the aerodynamic characteristics of the reflux device.

Contents of the invention

The purpose of this utility model is to address the deficiencies in the prior art and propose a reflux device with long and short blades to ensure that the model stage of the centrifugal compressor can operate safely and stably under small flow conditions and avoid secondary reflux inside the reflux device and other unstable phenomena, and enhance the stability of operation.

The technical scheme that the utility model adopts is as follows:

The utility model comprises a chassis and long blades and short blades welded on the chassis; a plurality of long blades are uniformly distributed along the circumference of the chassis, and short blades are arranged between two adjacent long blades.

Both the long blade and the short blade are arc-shaped, and the arc length of the short blade is 1/3-1/2 of the long blade; the distance ratio between the short blade and two adjacent long blades is 5-8 : 9, all short blades are evenly distributed along the circumference of the chassis.

The beneficial effects of the utility model are:

If CFD technology is used for numerical simulation, it can be found that under the condition of small flow rate, the phenomenon of secondary backflow between the vanes of the reflux device with short blades is significantly reduced, and the addition of the reflux device with short blades can improve the operating efficiency of the centrifugal compressor model stage. Compared with the case without short blades, it is increased by 1 to 5%, thus improving the safety and stability of the centrifugal compressor model stage under small flow conditions.

Description of drawings

Fig. 1 is the schematic diagram that the utility model is assembled on the centrifugal compressor model stage;

Fig. 2 is a structural schematic diagram of the utility model.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

As shown in Figures 1 and 2, a reflux device with long and short blades includes a chassis 5 and long blades 4 and short blades 6 welded on the chassis 5; eleven long blades 4 are evenly distributed along the circumference of the chassis 5, and Short blades 6 are arranged between two adjacent long blades, which can effectively prevent the occurrence and development of secondary backflow.

As shown in Figure 2, both the long blade and the short blade are arc-shaped, and the arc length of the short blade is 1/3 of the long blade; the distance ratio between the short blade 6 and two adjacent long blades 4 is 5:9, all The short blades are evenly distributed along the circumference of the chassis 5 .

The working principle of the reflux device with long and short blades:

The three-way impeller 1 rotates to do work on the gas, and the gas after the work done by the three-way impeller 1 is discharged through the blade diffuser 2, passes through the bend 3, enters the reflux device with long and short blades, and then is discharged from the outlet.

When the model stage of the centrifugal compressor operates under the condition of small flow rate, when the gas flows through the reflux device, there will be obvious secondary reflux. The short blades near the inlet of the reflux device are used to change the flow field, thereby effectively avoiding the occurrence of secondary reflux. Generated, expanding the range of safe and stable operation of the centrifugal compressor model stage.

Claims (1)

1., with a return channel for deviated splitter vane, comprise chassis and the linear leaf that is welded on chassis and short blade, it is characterized in that: multi-disc linear leaf is uniform along the circumference on chassis, between adjacent two panels linear leaf, be equipped with short blade; Described short blade is arranged on linear leaf inlet, and the import of short blade and linear leaf is equal to the distance of center chassis; Described linear leaf and short blade are all curved, and the arc length of short blade is 1/3 ~ 1/2 of linear leaf; The gap ratio of described short blade and adjacent two panels linear leaf is 5 ~ 8:9, and all short blades are uniform along the circumference on chassis.