CN1081757C - Centrifugal compressor and diffuser for centrifugal compressor - Google Patents
Centrifugal compressor and diffuser for centrifugal compressor Download PDFInfo
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- CN1081757C CN1081757C CN96180179A CN96180179A CN1081757C CN 1081757 C CN1081757 C CN 1081757C CN 96180179 A CN96180179 A CN 96180179A CN 96180179 A CN96180179 A CN 96180179A CN 1081757 C CN1081757 C CN 1081757C
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Abstract
The present invention relates to a multi-stage centrifugal compressor with multiple blade wheels installed on a rotating shaft or a single-stage centrifugal compressor with a blade diffuser which is provided with multiple guide blades and is installed on the down stream side of the blade wheel and a blade-free diffuser part formed in the down stream of the blade diffuser. The blade diffuser has a small wing chord pitch ratio, and each meridian plane of the two wall surfaces of the blade-free diffuser formed in the down stream of the blade diffuser presents a cross section shape that the flow passage height is gradually decreased in the direction of the down stream. The ratio of the flow passage height of the inlet to the flow passage height of the outlet of the blade-free diffuser is 0.3 to 0.6. A second blade diffuser with a small amount of guide blades can be used for replacing the blade-free diffuser. In one case, two wall surfaces forming the second blade diffuser can also be gradually contracted in the direction of the down stream. In another case, the flow passages are contracted in the position of the down stream of the blade diffuser to prevent the generation of obvious rotary separation in a low specific speed blade wheel, and therefore, the efficiency of the compressor is enhanced by the blade diffuser.
Description
The present invention relates to a kind of centrifugal compressor and the Diffuser that is used for centrifugal compressor, particularly relate to a kind of centrifugal compressor and the centrifugal blower of a small amount of gas and Diffuser that is used for them handled.
The Diffuser that is used for centrifugal compressor is divided into vaneless diffuser and vaned diffuser usually, in these Diffusers, vaned diffuser changes flow direction by stator, by stator flow velocity is reduced, therefore, near the efficient the design flow rate is compared with vaneless diffuser and is wanted high usually.Yet because stator has increased loss and stator makes flow separation, efficient is low when big flow rate and small flow rate, thereby operating range narrows down.
Therefore, disclose a kind of Diffuser (hereinafter being called low close vaned diffuser) that has winglet chordal pitch ratio in Japanese patent unexamined publication number 53-119411, wherein, even use vaned diffuser, operating range is not narrow yet, and can increase efficient.
Japanese Utility Model is not examined in the example that publication number 56-97598 discloses, and sharply narrow down at the runner height that is positioned on the no leaf part in low close vaned diffuser downstream, and the flow channel length that does not have a leaf part shortens, to reduce frictional loss.In addition, in the example that Japanese patent unexamined publication number 1-125599 discloses, in the compressor stage that has than low-specific-speed, the runner height that the leaf part is arranged of vaned diffuser reduces gradually at downstream direction, thereby because of having reduced frictional loss, has strengthened efficient.
Be used under the impeller situation of so-called low-specific-speed compressor, wherein, be not more than 250 (rpm, m by the specific speed of the adiabatic head of rotating speed flow rate and compressor decision
3/ min, m), the discharge flow angle of impeller is just less in the flow angle of diffuser inlet, and the axial height of the runner that flows is lower.Therefore, when vaneless diffuser is used as Diffuser, has the shortcoming that increases frictional loss.On the other hand, when vaneless diffuser was used in the low-specific-speed compressor stage, the vaneless diffuser part can produce the rotation separation in many cases.Therefore, in the higher multistage compressor of the pressure of working medium, make fluid oscillating limit the shortcoming of operating range thereby have because of rotation separates.
In order to prevent operating range to be narrowed down, the various methods that rotation separates that delay to produce when using vaneless diffuser, are provided because of rotation separates.One of method is to reduce the height (reduce the runner height in certain section and will be referred to below " contraction ") of fluid course in the diffuser inlet part, thereby be converted to low flow rate in the flow rate of separating initial point.Yet the efficient of the Diffuser of this structure is lower than the vaned diffuser, in addition, comprises that fluid course height Diffuser, that stablize runner is lower, increases the shortcoming that frictional loss increases thereby therefore have wet region.In addition, even use this Diffuser, be difficult to also prevent utterly that rotation from separating, reliability is minimized.
On the other hand, by using highly dense vaned diffuser can increase efficient (vaned diffuser has bigger wing chord pitch ratio).Yet, when using such vaned diffuser,, in addition, grip resistance owing in big flow rate zone, causing because the stator its separate produces fluctuation under small flow rate, have the shortcoming that operating range narrows down, thereby unactual.
The known efficient that has the low close vaned diffuser of less wing chord pitch ratio is higher than vaneless diffuser, can obtain the operating range of broad.Yet,,, must provide vaneless diffuser in the downstream of low close vaned diffuser in order to obtain bigger pressure recovery in order to adopt this low close vaned diffuser.Using under the low close vaned diffuser situation, the runner height that is positioned at the no leaf part in stator downstream has been made identical with the runner height of vaned diffuser so far.Adopting low close vaned diffuser can not make to flow fully turns to.Therefore, as the fluid input angle that enters in the Diffuser is less, even deflect flow to Diffuser has the degree in the leaf part, also can produce rotation in no leaf part and separate, and in this case, has limited operating range.
Do not examine in the disclosed example of publication number 56-97598 in above-mentioned Japanese Utility Model, consider that Diffuser can be used in the compressor stage than higher specific speed, in the downstream of Diffuser stator, the runner height sharply shrinks, thereby has reduced the axial height of runner.Yet, in this known example, rotation is separated the operating range that any consideration of carrying out all is not enough to enlarge compressor.That is, in this known example, regard to down to prevent to rotate to separate and be at important 2 and do not take in.First is leaf part to be arranged and do not having runner aspect ratio (contraction ratio) between the leaf part.Do not examine in the disclosed example of publication number 56-97598 in above-mentioned Japanese Utility Model, this value is 0.6-0.9, still, and from preventing that it is not enough rotating the separation aspect.
Second is inhomogeneous because of Diffuser stator downstream flow, makes flowing instability.Diffuser stator downstream to be flowing in the periphery direction inhomogeneous because of the wake flow of stator, particularly in the low-specific-speed compressor stage, flow angle (at the angle of periphery direction detection) even at runner by also less after the leaf part is arranged.Because at the mobile of no leaf part is to slow down to flow, this uneven Flow Distribution is difficult to unanimity.In addition, owing to, flow to become unstable in that radially static pressure gradient is bigger.Therefore, if Diffuser in the rapid or discontinuous contraction of this no leaf part, becomes discontinuous at radially static pressure gradient, thereby can not consistent become unstable flowing of periphery direction, from preventing to rotate the viewpoint of separation, this obtains the opposite effect.
In the low-specific-speed compressor stage, the Inlet cone angle that enters Diffuser is less, therefore when the stator deficiency of Diffuser so that during deflect flow, or when the stator local detachment of Diffuser, have leaf portion downstream zone to cause to rotate separation at Diffuser.
Japanese patent unexamined publication number 1-125599 discloses an example, and wherein the stator of Diffuser makes deflect flow, and simultaneously, runner also is retracted, and does not need to apply on stator bigger load, and the leaf part that has of Diffuser just can make mobile sizable deflection that has.In this known example, the flow angle that Diffuser has the no leaf of leaf portion downstream partly to enter the mouth is bigger, thereby can obtain to reduce the advantage of no leaf part flow channel length.Yet the whole runner height of no leaf part becomes lower, and the wet region of fluid becomes bigger.Therefore, the two influence is cancelled out each other, and makes the effect that partly reduces friction loss at no leaf fail to be enough to disclose.
As above-mentioned, particularly in the low-specific-speed centrifugal compressor stage, except the performance of representing by efficient and operating range, prevent that it is important producing the rotation separation in the Diffuser, but, in above-mentioned conventional art, also do not take into full account and satisfy these requirements simultaneously.
An object of the present invention is to provide a kind of centrifugal compressor, have than the low-specific-speed centrifugal compressor stage, specific speed is 80-250, prevented that wherein the rotation that produces in the Diffuser from separating, and has a high efficiency, wide operating range and high reliability, and a kind of Diffuser that is used for centrifugal compressor also is provided.
Another object of the present invention provides the Diffuser that a kind of centrifugal compressor is used, and wherein, it is simple to prevent to rotate separated structures, and cost is low, and a kind of centrifugal compressor with this Diffuser also is provided.
Another purpose of the present invention provides a kind of Diffuser that is used for multistage centrifugal compressor that prevents to rotate separation, and a kind of centrifugal compressor with this Diffuser also is provided.
In order to obtain above-mentioned purpose, according to one aspect of the present invention, a kind of single-stage or multistage centrifugal compressor are provided, comprise: a running shaft, one or more impellers that are installed on the running shaft, with one first vaned diffuser, it is at the radially outer of at least one impeller and have two opposed wall surfaces and a plurality of being arranged between the wall surface, first stator in the circumferencial direction space, wherein, vaneless diffuser is positioned at the downstream side of first vaned diffuser, described vaneless diffuser has two opposed wall surfaces, and the axial distance between the two reduces gradually from inlet to outlet.
According to another aspect of the present invention, a kind of single-stage or multistage centrifugal compressor are provided, comprise: a running shaft, one or more impellers that are installed on the running shaft, with a vaned diffuser, it is at the radially outer of at least one impeller and have two opposed wall surfaces and a plurality of being arranged between the wall surface, first stator in the circumferencial direction space, wherein, in the downstream side of first vaned diffuser second vaned diffuser is set, described second vaned diffuser has second stator of two opposed wall surfaces and a plurality of space settings along the circumferential direction between wall surface, and the axial distance between two wall surfaces of described second vaned diffuser reduces gradually from inlet to outlet.
Preferably, the meridian plane sectional shape that forms in two wall surfaces of vaneless diffuser each is by a smooth line that comprises a straight line or an arc.
Preferably, at the inlet guide vane angle of first stator periphery orientation measurement, first vaned diffuser be 4 °-12 °.
Preferably, the axial height of vaneless diffuser outlet is than the big 0.3-0.6 of axial height times of described first vaned diffuser outlet.
Form vaneless diffuser one of opposed wall surface radially be arranged to the meridian plane cross section, and another wall surface tilts near a described wall surface gradually at downstream direction.
Distance between two opposed walls surfaces of the blade height at impeller outlet place and first vaned diffuser equates.
Two opposed wall surfaces that form vaneless diffuser all tilt to tilt along downstream direction towards the sidepiece corresponding to the impeller central layer gradually.
Preferably, the specific speed of impeller is 80-250, and particularly, the specific speed of impeller is 100-200.
Preferably, first stator of first vaned diffuser has such size, makes in outlet perpendicular to the first adjacent stator of the not crosscut of line of first stator.
In order to obtain above-mentioned purpose of the present invention; according to a third aspect of the present invention; a kind of single-stage or multistage centrifugal compressor are provided; comprise: a running shaft; one or more impellers that are installed on the running shaft; with one first vaned diffuser; it the radially outward of at least one impeller and have two opposed wall surfaces and a plurality of be arranged between the wall surface, at first stator of circumferencial direction space; wherein, the rotation that prevents the fluid rotation separation that impeller flows out separates the outer periphery that protective gear is centered around first vaned diffuser.
In order to obtain above-mentioned purpose, according to a fourth aspect of the present invention, a kind of Diffuser is provided, comprise: the first vaned diffuser part on the outer periphery of impeller, be centered around a vaneless diffuser part of the first vaned diffuser part outer periphery, first vaned diffuser partly has the stator of two opposed wall surfaces and a plurality of space settings along the circumferential direction between wall surface, and vaneless diffuser with two opposed wall surfaces, wherein, in the meridian cross section, the distance that forms between vaneless diffuser two wall surfaces partly reduces rallentando from the inboard to the outside.
Fig. 1 is the longitudinal section of multistage centrifugal compressor of the present invention.
Fig. 2 is the longitudinal section of Fig. 1 centrifugal compressor intergrade, and diffuser portion mainly is shown enlargedly.
Fig. 3 is the sectional view along A-A line among Fig. 2.
Fig. 4-Fig. 8 illustrates the longitudinal section of another embodiment of the present invention, and the diffuser portion of amplification mainly is shown respectively.
Fig. 9 is an embodiment's of a vaned diffuser of the present invention plan view.
Figure 10 and 11 is longitudinal sections of further embodiment of this invention, and the diffuser portion of amplification mainly is shown respectively.
Figure 12 is single-stage radial compressor one an embodiment's of the present invention longitudinal section.
Several embodiments of the present invention are described below with reference to accompanying drawings.Fig. 1 illustrates the longitudinal section of multistage centrifugal compressor of the present invention.Axially be deposited in together to form multistage centrifugal compressor 100 with the compressor unit that multistage mode forms by a plurality of impeller 1a-1e and a plurality of Diffuser that constitutes by vaned diffuser 2a-2e and vaneless diffuser 3a-3e.That is, a plurality of impeller 1a-1e are deposited in the rotating shaft 8 vertically, and the two ends of rotating shaft 8 are rotatably mounted by bearing 10 respectively.Vaned diffuser 2a-2e lays respectively at impeller 1a-1e radially outer (being the downstream side of impeller 1a-1e), also has vaneless diffuser 3a-3e respectively at the radially outer of these vaned diffusers.Vaneless diffuser 3a-3e in all grades except afterbody is connected with return bend 4 respectively, and each return bend is supplied with next stage with working medium, forms the loop 5 of radially inwardly supplying with working medium in the downstream side of each return bend 4.In the end the downstream side of one-level vaneless diffuser 3e forms a membranous cochlea 6 (scroll), enters the discharge pipe (not shown) with the working medium of collection afterbody impeller outflow and with it.Vaned diffuser 2a-2e, vaneless diffuser 3a-3e, return bend 4, loop 5 and membranous cochlea 6 all are fixed blocks, fix or are formed on the compressor housing 7.Prevent that the inter-stage hermetic unit of revealing 12 is formed between any two successive stages of compressor.At this, every grade vaneless diffuser except afterbody is the part that extends to the beginning bending position 61 of return bend 4 from the stator outer radial position 60 of vaned diffuser, and the vaneless diffuser of afterbody is the part that extends to the wall surface end that stretches into the membranous cochlea housing 6 from the outer radial position of vaned diffuser.
Action to the multistage centrifugal compressor of formation like this is illustrated below.Pressure through the working medium of import 9 inspirations is increased by first order impeller 1a, in the time of by vaned diffuser part 2a and vaneless diffuser part 3a, pressure further increases, then, flow direction by return bend 4 working mediums changes, become radially inward direction from the radially outward direction, afterwards, working medium 5 infeeds second level impeller through the loop, then, repeats such flowing at each grade, thereby the pressure of working medium is increased gradually, and working medium by discharging membranous cochlea 6, infeeds discharge pipe by behind the afterbody Diffuser.In this multistage centrifugal compressor, reduce gradually from the specific speed (specific speed) of the first order towards afterbody, usually, in the end near the specific speed the one-level is less than 200.
Fig. 2 illustrates Fig. 1 multistage compressor one-level detail drawing partly that extends towards next stage from the exit portion of impeller.Fig. 3 is the view along Fig. 2 A-A line.The outlet 61 of the height b of the shaft orientation flowing channel of every grade of vaneless diffuser part 3 from the outlet 60 of vaned diffuser part 2 (inlet of vaneless diffuser part) to vaneless diffuser radially outwardly gradually or minimizing lentamente.A wall surface 58 that constitutes vaned diffuser 2 and vaneless diffuser 3 forms with integral way, its inner diameter end from impeller outlet partly, and its external diameter end is arranged on return bend 4 beginning bent position.
In the present embodiment, see Fig. 2, the stator 2z of the vaned diffuser that equates with the blades height of impeller basically by its guide vane height, the flow direction change of the working medium that flows out from impeller, and this working medium flow in the vaneless diffuser part 3.In low-specific-speed (specific speed is no more than 200) compressor stage,, strengthen ride quality by reducing the discharge angles of impeller.And traditional method at diffuser exit contracted channel width has increased the zone that produces fluctuation, and this is undesirable, it is desirable to the established angle α of Diffuser stator is reduced to 4 °-12 °.If this established angle α increases to a certain degree, by the deflection of stator 2z, increased flow angle to flowing to, separate thereby can suppress rotation.Yet in the present embodiment, established angle α can not increase a lot under stator 2z makes deflect flow and slows down even enter the Inlet cone angle of the working medium of no leaf part 3 during less than 12 ° yet.Formed by parallel wall under the situation in no leaf part 3, flowing state is shown in Fig. 3 dotted line.As a result, the average flow angle of working medium diminishes, and under wake flow 14 influences of Diffuser stator 2z, it is unstable to flow, and easily rotates separation.
In the present embodiment, the wall 31 corresponding to the vaneless diffuser part 3 of impeller side plate tilts in the radially outward direction gradually towards the sidepiece corresponding to the impeller central layer.In the embodiment shown in Figure 2, the runner height b of vaneless diffuser part 3 reduces in substantial linear radially, and by so reducing the runner height of vaneless diffuser part 3 gradually, that can realize Fig. 3 flows 20, and compares with mobile 20a, and flow angle is bigger.Therefore, can suppress the formation in wall surface boundary layer, flow and stablized, and can suppress rotation and separate.In the present embodiment, contraction ratio b
2/ b
1Be about 0.5.If this contraction ratio b
2/ b
1Less, then the average flow angle of the working medium in the vaneless diffuser part 3 becomes bigger, has strengthened the protection effect that rotation separates, and has also strengthened to overcome the reliability that rotation separates.Yet, if contraction ratio b
2/ b
1Reduce, the runner height in vaneless diffuser part 3a-3e downstream also reduces, and then wet region (wetted perimeter area) can increase, thereby the frictional loss meeting increases.Therefore, contraction ratio b
2/ b
1For 0.3-0.6 is desirable, be preferably about 0.5.
As above-mentioned, must between any two successive stages of multipole compressor, hermetic unit 12 be set, therefore, the inwall width L of return bend 4 is greater than predetermined length obviously.Therefore, under low-specific-speed level situation, the radius of curvature r of return bend 4 unnecessarily increases, and has increased loop length, thereby increases frictional loss.In the present embodiment, tilt near the diffuser walls portion 31 (just in that side of side plate corresponding to impeller) of previous stage, the loop height of no leaf part reduces gradually at downstream direction.Adopting this structure, is to compare when tilting with wall 31 corresponding to the central layer of impeller, and the inwall radius of curvature r of return bend 4 can do very for a short time, thereby can reduce the frictional loss in the return bend 4.
Fig. 4 is corresponding to Fig. 2, another embodiment's of Diffuser of the present invention longitudinal section.Present embodiment is with the different of Fig. 2 embodiment, tilts towards the sidepiece corresponding to the impeller side plate corresponding to the wall surface 34 of the no blade to enlarge pressure part 3 of impeller central layer.In the present embodiment, two wall surfaces 33 of vaneless diffuser part and 34 form so that the inclination mode is linear, and reduce gradually at downstream direction runner height, thereby the shrinkage degree of runner is basic identical with opposed wall surface, therefore two wall surfaces form roughly the same boundary layer, can make the Flow Distribution of runner short transverse more even, can strengthen the recovery of static pressure in the vaneless diffuser part 3.
Fig. 5 illustrates modified example embodiment illustrated in fig. 4, two walls 35 of the vaneless diffuser part 3 of close vaned diffuser, 36 each part are that the curved surface of R1 forms by radius of curvature, be that the curved surface of R2 forms by radius of curvature simultaneously near each part of two walls of return bend, the profile of two walls is roughly the same, and the runner height shrinks gradually at downstream direction.In this modified example, runner shrinks lentamente, thereby liquid stream is milder in Diffuser, thereby can further obtain to reduce the effect of flow losses in vaneless diffuser.
Fig. 6 illustrates Fig. 2 embodiment's modified example, be that the arc of R1 forms corresponding to the wall surface 37 of the vaneless diffuser 3 of impeller side plate by radius of curvature, and the runner of vaneless diffuser 3 shrinks gradually at downstream direction.In this modified example, to compare with embodiment shown in Figure 2, its shortcoming is, processing inconvenience and increased wet region.Yet, the shrinkage of the first half of vaneless diffuser 3 runners is increased, increased the meridional velocity (meridian plane speed) of vaneless diffuser part 3 the first halfs, thereby the flow angle of early stage vaneless diffuser part 3 just can increase, therefore, obtain to prevent to rotate the surprising effect of separation.That is, this modified example provides to rotate to separate to protect with being better than performance and is suitable for.In this modified example, although the wall surface corresponding to the vaneless diffuser of impeller side plate forms smooth surface by an arc, this wall surface also can be by being joined together to form curved surface with the polylith arc, perhaps can with an arc and always toe-in close and form smooth curved surface.Adopt this layout, just can easily form very smooth curved surface by the NC machining tool.
Fig. 7 is another modified example of Fig. 2 embodiment, and by two arc R1 and R2 are linked together, the wall 39 of the vaneless diffuser 3 of close vaned diffuser 2 just forms a flexure plane.In this modified example, can obtain to be similar to the effect that Fig. 2 embodiment is obtained, the same also slightly inconvenience of processing of comparing Diffuser with Fig. 2 embodiment, but compare with Fig. 2 embodiment, can obtain to reduce the effect of flow losses in the vaneless diffuser part 3.
Fig. 8 is the longitudinal section of further embodiment of this invention, and its sectional elevation of Fig. 9.Replace second vaned diffuser 50 of vaneless diffuser to have the downstream that three rotation protection guide plate 40, the second Diffusers 50 are positioned at vaned diffuser 2, and the runner height of this second vaned diffuser 50 shrink gradually at downstream direction.
In a vaneless diffuser, when the adverse current in boundary layer takes place in the part, will cause the generation separated flow, and this separated flow rotates in Diffuser, separate thereby produce rotation.In the present embodiment, even when producing little adverse current in replacing the 2nd vaned diffuser part of traditional vaneless diffuser, rotation protection guide plate can make rotation stop, and therefore can prevent to produce large-scale separated flow.For this reason, preferably provide several rotation protection aprons 40, in the present embodiment, protection apron is 3.Adopt this structure, can prevent more reliably that rotation from separating, and the compressor of high reliability can be provided.When rotation protection apron 40 is provided, the contraction ratio b of the second vaned diffuser part 50
2/ b
1Can be arranged to bigger than 0.3-0.6.
Figure 10 and 11 illustrates the additional embodiments of Diffuser of the present invention respectively, forms two wall surfaces 41 and 42 of vaneless diffuser part 3, and two wall surfaces 44 and 45 that form second vaned diffuser 50 tilt towards the side plate corresponding to the impeller central layer.In addition, each runner height of the vaneless diffuser part 3 and the second vaned diffuser part 50 shrinks gradually at downstream direction.When adopting this structure, determine to install the necessary axial length L of intermediate seal 12, can reduce return bend 4 inwall radius of curvature r.
Vaned diffuser 2 and vaneless diffuser 3 have reduced flow velocity, are not different but the inlet radius of return bend 4 goes out port radius with it.Therefore, in the low-specific-speed level of the bigger compressor of its peripheral member, flow velocity does not reduce, and flow channel length is big more, and then frictional loss is big more.Therefore, as the radius of curvature of the minimizing return bend inwall in the present embodiment, can obtain to reduce the effect of frictional loss in the return bend part.
Figure 12 illustrates single-stage radial compressor, and impeller 1 is installed on the running shaft 8a, and fluid passes through impeller 1, vaned diffuser part 2 and vaned diffuser part 3, and from membranous cochlea housing 6, discharge.At this, vaneless diffuser part 3 is the parts that extend to wall surface 46 ends that put in the membranous cochlea housing 6 from the outer radial position of the stator of vaned diffuser part 2.In the present embodiment, tilt towards radially outward corresponding to the wall surface 46 of impeller side plate (forming one of two wall surfaces of vaneless diffuser part 3), and tilt towards wall surface 46 corresponding to the wall surface 47 of impeller central layer.Adopt this structure, fluid shrinks gradually at downstream direction.Membranous cochlea 6 is formed at the downstream of diffuser portion, collects the working medium of discharging from impeller 1, and it is supplied with the discharge pipe (not shown).Vaneless diffuser is retracted, and adopts this layout, can not influence fluid property and not influence inhibition rotation separating effect ground freely to select the outlet housing.In the present embodiment, irrespectively obtain to prevent to rotate the effect of separating with the impeller specific speed, still, less and when particularly being no more than 200 when specific speed, this effect is very surprising.
In addition, in above-mentioned arbitrary embodiment, vaned diffuser has been not limited to leaf shape, can use the Diffuser of any kind.Yet its effect is significant in low close vaned diffuser.At this, term " the low close vaned diffuser " meaning for its stator short so that do not pass adjacent guide vane perpendicular to the line of the Inlet cone angle of Diffuser stator, and the value that the wing chord length of pitch mean value that Diffuser stator inlet pitch and Diffuser stator are exported and Diffuser stator is divided by is not more than 1.
As above-mentioned, in the present embodiment, (specific speed is 80-250 in the low-specific-speed level of multistage centrifugal compressor, 100-200 preferably) in, form the vaneless diffuser part or form second vaned diffuser, two wall surfaces partly that are positioned at the vaned diffuser downstream and shrink gradually at downstream direction, adopt this structure, can obtain to prevent to rotate the effect of separation.(specific speed is 80-250 in the low-specific-speed level of single-stage radial compressor, 100-200 preferably) in, the vaneless diffuser part that is positioned at the vaned diffuser downstream is shunk gradually at downstream direction, adopts this structure, can be prevented the compressor that rotation separates and have the broad operating range.
Preferred embodiment of the present invention is illustrated by example, but is not limited, and scope of the present invention is presented in the appending claims, and the present invention includes any interior change of scope that drops on claims.
Claims (16)
1. multistage centrifugal compressor, comprise: a running shaft, a plurality of impellers that are installed on the described running shaft, with one first vaned diffuser, it the radially outer of the one-level at least of described impeller and have two opposed wall surfaces and a plurality of be arranged between the described wall surface, at first stator of circumferencial direction space; It is characterized in that, be provided with vaneless diffuser in the downstream side of described first vaned diffuser, described vaneless diffuser has two opposed wall surfaces, and the axial distance between the two reduces gradually from inlet to outlet.
2. according to the described centrifugal compressor of claim 1, it is characterized in that each the meridian plane sectional shape of described two wall surfaces that forms described vaneless diffuser is made of straight line.
3. according to the described centrifugal compressor of claim 1, it is characterized in that each the meridian plane sectional shape of described two wall surfaces that forms described vaneless diffuser comprises an arc.
4. according to the described centrifugal compressor of claim 1, it is characterized in that, is 4 °-12 ° at the inlet guide vane angle of first stator periphery orientation measurement, described first vaned diffuser of first stator of described first vaned diffuser.
5. according to claim 1 or 4 described centrifugal compressors, it is characterized in that the axial height of described vaneless diffuser outlet is that the 0.3-0.6 of axial height of described first vaned diffuser outlet is doubly big.
6. multistage centrifugal compressor, comprise: a running shaft, a plurality of impellers that are installed on the described running shaft, with one first vaned diffuser, it the radially outer of the one-level at least of described impeller and have two opposed wall surfaces and a plurality of be arranged between the described wall surface, at first stator of circumferencial direction space; It is characterized in that, be provided with one second vaned diffuser in the downstream side of described first vaned diffuser, described second vaned diffuser has second stator of two opposed wall surfaces and a plurality of space settings along the circumferential direction between described wall surface, and the axial distance between two wall surfaces of described second vaned diffuser reduces gradually from inlet to outlet.
7. according to claim 1 or 6 described centrifugal compressors, it is characterized in that one of described opposed wall surface that forms described vaneless diffuser radially is arranged to the cross section of meridian plane, and another wall surface moves closer to a described wall surface at downstream direction.
8. according to claim 1 or 6 described centrifugal compressors, it is characterized in that the distance between two opposed walls surfaces of the blade height at described impeller outlet place and described first vaned diffuser equates.
9. according to claim 1 or 6 described centrifugal compressors, it is characterized in that described two the opposed wall surfaces that form described vaneless diffuser all tilt along downstream direction gradually towards the sidepiece corresponding to described impeller central layer.
10. according to claim 1 or 6 described centrifugal compressors, it is characterized in that the specific speed of described impeller is 80-250.
11., it is characterized in that the specific speed of described impeller is 100-200 according to claim 1 or 6 described centrifugal compressors.
12., it is characterized in that first stator of described first vaned diffuser has such size according to claim 1 or 2 described centrifugal compressors, make perpendicular to the line of described first stator not crossing with the first adjacent stator.
13. centrifugal compressor, comprise: a running shaft, an impeller that is installed on the described running shaft, with a vaned diffuser, it the radially outer of described impeller and have two opposed wall surfaces and a plurality of be arranged between the described wall surface, at the stator of circumferencial direction space; It is characterized in that, in the downstream side of described vaned diffuser one vaneless diffuser is set, described vaneless diffuser has two opposed wall surfaces, and the axial distance between two wall surfaces reduces lentamente gradually from inlet to outlet.
14., it is characterized in that the scope of the specific speed of described impeller is 80-250 according to the described centrifugal compressor of claim 13.
15., it is characterized in that the stator of described vaned diffuser has such size according to the described centrifugal compressor of claim 13, feasible not crosscut of line adjacent guide vane perpendicular to described stator.
16. Diffuser, comprise: the vaned diffuser part that is located at the outer periphery of impeller, one is centered around the vaneless diffuser part of the outer periphery of described vaned diffuser, described vaned diffuser partly has the stator of two opposed wall surfaces and a plurality of space settings along the circumferential direction between described wall surface, and described vaneless diffuser has two opposed wall surfaces; It is characterized in that on the meridian cross section, the distance that forms between two wall surfaces of described vaneless diffuser reduces gradually from the inner to the outer end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN96180179A CN1081757C (en) | 1996-03-06 | 1996-03-06 | Centrifugal compressor and diffuser for centrifugal compressor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN96180179A CN1081757C (en) | 1996-03-06 | 1996-03-06 | Centrifugal compressor and diffuser for centrifugal compressor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1214106A CN1214106A (en) | 1999-04-14 |
| CN1081757C true CN1081757C (en) | 2002-03-27 |
Family
ID=5127755
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN96180179A Expired - Lifetime CN1081757C (en) | 1996-03-06 | 1996-03-06 | Centrifugal compressor and diffuser for centrifugal compressor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1081757C (en) |
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| CN101504015B (en) * | 2008-02-06 | 2013-03-20 | 株式会社Ihi | Turbo compressor and refrigerator |
| CN101952601B (en) * | 2008-02-20 | 2013-06-19 | 特灵国际有限公司 | Centrifugal compressor assembly and method |
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| US8016557B2 (en) * | 2005-08-09 | 2011-09-13 | Praxair Technology, Inc. | Airfoil diffuser for a centrifugal compressor |
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| JP2014047775A (en) * | 2012-09-04 | 2014-03-17 | Hitachi Ltd | Diffuser, and centrifugal compressor and blower including the diffuser |
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| CN110081024B (en) * | 2019-03-25 | 2021-06-22 | 沈阳鼓风机集团股份有限公司 | Guide vane of multistage centrifugal pump and machining method thereof |
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| JPH0520597U (en) * | 1991-08-27 | 1993-03-19 | アンフアン株式会社 | Cooler for beer |
| JPH05133397A (en) * | 1991-11-13 | 1993-05-28 | Hitachi Ltd | Multistage centrifugal compressor |
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|---|---|---|---|---|
| FR2419415A1 (en) * | 1978-03-07 | 1979-10-05 | Kawasaki Heavy Ind Ltd | MULTI-STAGE TURBOCHARGER WITH DIAGONAL FLOW ROTORS |
| JPH0520597U (en) * | 1991-08-27 | 1993-03-19 | アンフアン株式会社 | Cooler for beer |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101504015B (en) * | 2008-02-06 | 2013-03-20 | 株式会社Ihi | Turbo compressor and refrigerator |
| US8601832B2 (en) | 2008-02-06 | 2013-12-10 | Ihi Corporation | Turbo compressor and refrigerator |
| CN101952601B (en) * | 2008-02-20 | 2013-06-19 | 特灵国际有限公司 | Centrifugal compressor assembly and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1214106A (en) | 1999-04-14 |
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