CN202170894U - Short-vane type diffuser - Google Patents

Abstract

The utility model relates to a short-vane type diffuser, comprising a front wall surface, a back wall surface and short vanes, wherein the diffuser is uniformly divided into an inlet section and an outlet section along a radial direction; the utility model is characterized in that the shape of the short vanes is arc; the arrangement of the short vanes is low gate viscosity; the short vanes are arranged on the outlet section of the back wall surface. The short-vane type diffuser has the advantages of the vane diffuser and the vaneless diffuser, has a working area of which wide is the same as that of the vaneless diffuser, drastically improves the efficiency and has almost the same pressure ratio as the vane diffuser. The short-vane type diffuser is beneficial to promote wide application of the vortex supercharger, particularly in vehicle engines, and reduces waste gas emission when improving performance of the engine.

Description

A kind of short-vane type diffuser

Technical field

The utility model relates to a kind of short-vane type diffuser that is used for centrifugal compressor, particularly about a kind of variable geometry turbine compressor short-vane type diffuser of (being called for short VGC) that is used for.

Background technique

In recent years; Develop rapidly is paid much attention to and obtained to variable geometry turbine technology (being called for short VGT) why; One of its major reason; This exactly technology can be improved the adaptive capacity of turbosupercharger for vehicle motor variable working condition characteristic, thereby can improve power character, Economy and the reduction toxic emission of motor significantly.Generally, mainly concentrate on impeller and the entry guide vane and the vaneless diffuser aspect of turbo machine, compressor for the research of VGT.Such as, the VGT model machine that Britain HOLSET company takes the lead in producing just is to use vaneless diffuser, yet, though vaneless diffuser has broader working field, can not reach higher efficient and pressure ratio.If use general vaned diffuser, though can improve peak efficiencies and pressure ratio, seeming owing to its working zone is too narrow loses more than gain, thereby seldom in VGT, uses.U.S. Pat 4850795 has proposed a kind of variable-geometry vaned diffuser, and it is that Diffuser is divided into two zones, at the front face of Diffuser the biserial leaf grating is set, and cascade solidity is low grid denseness in entry zone, and exit region is high grid denseness; The blade longitudinal section of this patent is a wedge type, and blade surface is the log spiral type, and processing technology is complicated; The log spiral type can only be effective to a certain flow, and to the bad adaptability of changes in flow rate, though it has alleviated the rear portion obstruction; But lost efficient; Especially exit region grid denseness is high, has limited the expansion of working zone, can not adapt to the needs of the changeable operating mode of vehicle motor comprehensively.U.S. Pat 3756739 has also proposed a kind of technical solution of variable-geometry vaned diffuser, and it is to adopt high grid denseness than linear leaf; Because high grid denseness blade has definite throat, working field is narrow, introduces the occasion of stator in the time of can only being used for small flow as the variable-geometry device; And when big flow; Open throat through the small leaf by auxiliary device control that is arranged on blade tip, therefore, structure and control mechanism be more complicated all.

Summary of the invention

To the problems referred to above, the purpose of the utility model provides a kind of simple in structure, and is easy to make, both had the working field of broad, has the short-vane type diffuser of higher working efficiency and pressure ratio again.

For realizing above-mentioned purpose; The utility model is taked following technological scheme: a kind of short-vane type diffuser, and it comprises front face, rear surface and short blade, said Diffuser radially is divided into inducer and outlet section; The radial length of said short blade is less than said arbitrary section; It is characterized in that: said short blade be shaped as circular arc, said short blade be arranged as low grid denseness, said short blade is arranged on the outlet section of said rear surface.

Said short blade also is arranged on the inducer of said front face.

The utility model is owing to take above technological scheme; It has the following advantages: 1, the utility model is owing to adopt low grid denseness circular arc short blade; And only this short blade is arranged on the outlet section of rear surface, is combined into the outlet short-vane type diffuser with the front face of no leaf, therefore; Can under the foolproof situation of structure, reach simultaneously than broad working field and higher working efficiency and pressure ratio.2, the utility model is because when the outlet section of rear surface is provided with low grid denseness short blade; Inducer at front face also is provided with low grid denseness short blade; Therefore, can be in the process of coaxial rotation front face or rear surface, through the variation of inducer and outlet section blade relative position; Realize the variation of how much through-flow runners at an easy rate, reached the purpose that adapts to various different flow operating mode needs.The utility model not only structure and control mode is very simple; And concentrated the advantage of vaned diffuser and vaneless diffuser simultaneously; The utlity model has and the same broad working zone of vaneless diffuser; And efficient has raising by a relatively large margin, and pressure ratio is almost identical with vaned diffuser especially.The utility model helps lend some impetus to the extensive use of vortex supercharger, and the especially application on vehicle motor can reach when improving engine performance, reduces the purpose of toxic emission.

Description of drawings

Fig. 1 is common centrifugal compressor vaneless diffuser schematic representation

Fig. 2 is the front face schematic representation that the utility model inducer has short blade

Fig. 3 is the rear surface schematic representation that the utility model outlet section has short blade

Fig. 4 is the utility model biserial leaf grating view

Fig. 5 is the utility model view that comes into leaves

Fig. 6 is that the utility model comes into leaves-biserial leaf grating Diffuser and vaneless diffuser performance comparison curve synoptic diagram

Fig. 7 is the low grid denseness of the utility model outlet and high grid denseness Diffuser and vaneless diffuser performance comparison curve synoptic diagram

Embodiment

Below in conjunction with accompanying drawing and embodiment, the utility model is carried out detailed description.

As shown in Figure 1, common centrifugal compressor vaneless diffuser comprises front face 1, and rear surface 2, front face 1 and rear surface 2 are actually to be made up of two concentric circles.The utility model with Diffuser by its radially effective length be divided into two zones, and be defined as inducer 3 and outlet section 4 by air-flow trend.

As shown in Figure 2, the utility model will hang down the inducer 3 that grid denseness short blade 5 is arranged on Diffuser front face 1, and low grid denseness short blade 6 is arranged on the outlet section 4 (as shown in Figure 3) of rear surface 2, above-mentioned short blade 5,6 be shaped as circular arc.

The said structure of the utility model can be formed following two kinds of Diffuser structural types:

1) outlet section 4 is had the rear surface 2 and 3,4 all vaneless front faces 1 combinations of inlet/outlet section of short blade 6, become low grid denseness outlet short-vane type diffuser.This Diffuser mode makes the air-flow that leaves impeller before getting into blade, and well-mixed chance is arranged, and has possessed the flow condition that gets into blade relatively uniformly; And,, therefore can improve the matching state of Diffuser and volute owing to adopt short blade that air-flow is imported dirty volute at outlet section 4.Therefore this structural type of the utility model expanded choked flow working field (is the boundary with 60% efficient point) owing to only at outlet section 4 low grid denseness short blade 6 is set, and makes it have surprising broad working field.Compare with vaneless diffuser, under the situation of the working field with same broadness, efficient has improved 8.6% (as shown in Figure 7), and pressure ratio is almost identical with vaned diffuser, and structure is very simple.

2) front face 1 that inducer 3 is had a short blade 5 make up (like Fig. 4, shown in Figure 5) relatively with the rear surface 2 that outlet section 4 has short blade 6, becomes to hang down the grid denseness and come into leaves-biserial cascade-type Diffuser.This Diffuser mode in use can be fixing with rear surface 2, and front face 1 is done coaxial rotation in the arc length of a runner.When the short blade 6 of outlet section 4 is positioned near the runner center elongation line of short blade 5 of entrance 3, just formed the biserial leaf grating Diffuser (as shown in Figure 4) that blade interlaces and arranges; When relative rotation reaches capacity the position, just become the common Diffuser that comes into leaves (as shown in Figure 5) with linear leaf.This structural type of the utility model, the variation of operating mode is done rotation relatively with forward and backward wall when needing only according to use, just can realize the variation of the through-flow runners of geometry.Like this; When small flow, can use the state of coming into leaves, obtain higher efficient and pressure ratio (as shown in Figure 6); And minimum flow (below the pumping point) or in during big flow; Then can use biserial leaf grating state, it still can obtained under the situation of greater efficiency and pressure ratio, obtain broader working field.The Diffuser of the utility model is because only need be through coaxial rotation front face or rear surface, and therefore, control mechanism also can be very simply.

Be the laboratory data of the utility model and the explanation of performance comparison curve below.

As shown in Figure 6, come into leaves with biserial cascade-type Diffuser in, forward and backward wall external diameter is ∮ 139mm, internal diameter is ∮ 87.6mm, the leaf height is 7mm.Blade outlet angle is 61.8 °; On behalf of Diffuser, T11 be in biserial leaf grating state among the figure, and on behalf of Diffuser, T9 be in the state of coming into leaves, and dotted line is represented vaneless diffuser, and 60K representes turbo machine under the experimental status that per minute 60,000 changes, and 70K representes that turbo machine is under the experimental status that per minute 70,000 changes.From the performance comparison plotted curve, can find out, when the small flow regional work, come into leaves-biserial cascade-type Diffuser; Forward and backward wall rotates to be the state of coming into leaves relatively, and Diffuser can obtain very high efficient and pressure ratio, but at flow during minimum or big-and-middle flow; It is narrow that the working zone can take place the state of coming into leaves; Thereby it is rotated to be biserial leaf grating state, Diffuser almost can obtain and the same broad working field of vaneless diffuser, but efficient and pressure ratio are but far above vaneless diffuser.

As shown in Figure 7, in the outlet short-vane type diffuser, forward and backward wall external diameter is ∮ 139mm, and internal diameter is ∮ 87.6mm, and the leaf height is 7mm, and blade outlet angle is 61.8 °; The low grid denseness outlet of T7 representative short-vane type diffuser among the figure, T3 represents high grid denseness outlet short-vane type diffuser, and dotted line is represented vaneless diffuser.From the performance comparison plotted curve, can find out, in during big flow, low grid denseness Diffuser is than the work field width of high grid denseness Diffuser, even when small flow, and is also wideer than the working field of vaneless diffuser; And aspect pressure ratio and efficient, low grid denseness Diffuser is higher than high grid denseness Diffuser, and is higher than vaneless diffuser, almost identical with the Diffuser that comes into leaves.

Above-mentioned each embodiment only is used to explain the utility model; Wherein the structure of each parts, Placement etc. all can change to some extent; Every equivalents of on the basis of the utility model technological scheme, carrying out and improvement all should not got rid of outside the protection domain of the utility model.

Claims (2)

1. short-vane type diffuser; It comprises front face, rear surface and short blade; Said Diffuser radially is divided into inducer and outlet section, and the radial length of said short blade is characterized in that less than said arbitrary section: said short blade be shaped as circular arc; The grid denseness is hanged down in being arranged as of said short blade, and said short blade is arranged on the outlet section of said rear surface.

2. short-vane type diffuser as claimed in claim 1 is characterized in that: said short blade also is arranged on the inducer of said front face.

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