DE60036336T2 - turbomachinery - Google Patents

Abstract

A turbo machine comprising: an impeller having a plurality of blades therewith; a casing having a flow surface defined therein and being positioned with the impeller therein; and a plurality of grooves being formed in the flow surface of the casing, for connecting between an inlet side of said impeller and an area on the flow surface of the casing in which the blades of said impeller reside, on a periphery thereof, wherein an index of determining a form of the grooves is obtained by a following equation: <DF>JE No. = WR x VR x WDR x DLDR </DF> where, WR (a width ratio) is a value obtained by dividing a total value of the groove widths W with a length of casing periphery; VR (a volume ratio) is a value obtained by dividing a total volume of said grooves with a volume of said impeller; WDR (a width-depth ratio) is a value obtained by dividing the width W of said groove with a depth D of said groove; and DLDR is a ratio between a length of said groove in flow, being lower than the impeller inlet and the depth of said groove, and wherein, said grooves are formed so that the index JE No. lies in a range from 0.03 to 0.5. <IMAGE>

Description

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

The The present invention relates to turbomachinery, and more particularly on a turbomachine, which is able to flow through instability Suppress a turbulence due to a recirculation flow on Inlet of an impeller and by suppressing rotational flow breaks of the impeller independently of its construction and the fluid to prevent.

More accurate said, the present invention relates to turbomachinery, such as a pump, a compressor, a blower, etc., which has an impeller a non-volume design, and in particular the turbomachinery, the flow instability thereby can prevent turbulence or Vorverwirbelung is suppressed due to a mainstream or a component of the occurring at an inlet of an impeller Recirculation is generated, and that rotational flow breaks are suppressed so that is suitable for a use with a Halbaxialpumpe is given, which in far Scope as water circulation pumps in a thermal power plant or used in a nuclear power plant or as a drainage pump, and to a pumping station where the turbo-machine according to the present Invention is used.

2. DESCRIPTION OF THE STAND OF THE TECHNIQUE

• 1. Nach Fluiden, mit denen die Maschine betrieben wird, nämlich Flüssigkeit und Gas.
• 2. Nach Bauweisen, nämlich Axial-, Halbaxial- und Radialbauweise.

"Turbomachinery" rotary machines may be classified as follows, depending on the fluids they are used with and their construction:

• 1. For fluids used to operate the machine, namely liquid and gas.
• 2. By construction, namely axial, Halbaxial- and radial construction.

In the 22 Semi-axial pump shown in cross-section, which is mainly or widely used today due to its simple operation, has an intake housing sequentially from upstream to downstream 11 , a pump 12 and a diffuser 13 ,

A shovel 122 in a housing 121 the pump 12 revolves, is from a wave 123 rotationally driven, causing the suction from the housing 11 sucked liquid energy is supplied. The diffuser 13 has the function to convert part of the velocity (or kinetic) energy of the liquid into static pressure.

23 shows a typical characteristic between the pumping height and throughput of the turbomachine for the in 22 shown with the horizontal axis shows a parameter that represents the throughput, while the vertical axis shows a parameter that stands for the pressure level.

Especially he falls Pressure in an opposite relationship to the increase in throughput in a low throughput area, but increases after Increase in throughput during the time while the throughput is in an area S (i.e., in a section, which rises on the right side of the characteristic or jumps up). If the throughput continues to increase and over the rising section If the characteristic on the right goes out, the pump height starts to increase the throughput drop again.

In the case in which the turbomachine with a throughput in the right-hand rising characteristic works, the liquid mass oscillates from itself, i. it creates a phenomenon of pumping.

Such a slope on the right side arises because the recirculation occurs at an outer periphery of the inlet of the impeller when the flow rate through the turbomachine is low, and in this case, the flow passage or a passage for the liquid flowing in the turbomachine flows, narrows, creating a vortex in the fluid (see 22 ).

There pumping not only at the turbomachine, but also at the Lines or pipes with their upstream and downstream sides connected damage generated, it must not occur in a low-throughput area. Instead of an improvement in the shape (i.e., in profile) of the blade, to expand or enlarge the operating range of the turbomachine Various methods for suppressing pumping have already been proposed. as stated below.

1. Housing processing

In a housing area, in which the impeller is, are thin or narrow grooves or procedures with 10% to 20% of the chord length the blade is designed to improve the stall tolerance.

24 (a) and (b) show, for example, views of the housing machining that have already been proposed. In particular shows 24 (a) a positional relationship between the case processing and the blades while 24 (b) the housing processing in cross sections shows.

Especially be in the already proposed housing machining the grooves in an inner wall (i.e., the flow surface) of the housing in the area where the blades lie, in the axial direction, in the circumferential direction or in an oblique Direction, alternatively in the radial direction or an oblique direction each formed with a sufficient depth.

Even though the mechanism, like the case processing the improvement of the stall tolerance allows theoretically not yet clearly examined, one can assume that the occurrence of developing cells thereby prevents the high pressure fluid from entering a low energy range sprayed out or is injected.

2. Separator

To the Dividing the recirculation flow, the at the outer edge of the inlet of the impeller occurs in a reverse flow section and a forward flow section (i.e., in a main flow direction) in the low flow area is a separator provided, whereby the expansion of the recirculation prevented becomes.

25 (a) bis (c) are, for example, views of separators, each of which is used in a turbomachinery in axial construction, in particular a construction with suction ring (in 21 (a) ), a blade separator construction (in 25 (b) ) and an air separation device construction (in 25 (c) ) proposed.

In the construction with the suction ring (in 25 (a) ), the return flow is enclosed within an outside of the suction ring, while in the construction with blade separator (in 25 (b) ) a rib is provided between the housing and the ring. In the construction with air separation device (in 25 (c) ), a leading end or a tip of the moving blade (ie, the blade) is further opened so that the return flows are introduced into the outside of the housing, thereby preventing the generation of a vortex due to the return flows by means of the rib. Compared to the previously mentioned two designs, this is more effective, but leads to large-scale devices.

3. Active control

there is said to generate vortex generation due to recirculation by injection or spraying of high pressure fluid from the outside suppressed to one place at which the recirculation occurs.

When example for conventional Turbomachinery will be further described below a Halbaxialpumpe. For one Semi-axial pump must have a pumping-height flow rate characteristic (hereinafter referred to as "pressure curve") which does not show a rising behavior on the right side, to allow in the case a stable operation in which the pump above the entire throughput area works. In a pump, however, it is common that the characteristics characteristics, such as efficiency Performance of the pump, the stability the pressure curve, the gravitational behavior, the axial motive power to close etc. are in opposite relationships. If trying to improve, worsen / worsen one of those properties the other one, so the problem is that it's difficult is improvements in at least two or more properties to receive at the same time. For example, in a pump, at the main the efficiency is considered, the pressure curve a considerable Rise behavior on the right side in a section of her, so there is a tendency for instability.

In order to obtain a pressure curve continuously decreasing on the right side to enable stable operation, it is known in the art as mentioned above that a case treatment is performed or a separator is provided. Such a structure is for example already in the U.S. Patent 4,212,585 or in that U.S. Patent 5,466,118 described.

SUMMARY OF THE INVENTION

Even though it, as mentioned above, during the case treatment and the separation devices of the prior art is possible, the characteristic between pressure altitude and throughput including the rising right-hand slope to the side with lower To shift throughput to extend the stable operating range, but it is impossible the rising characteristic or the rising behavior on the right Remove or exclude page. In addition, the efficiency decreases the turbomachine by about 1% for an increase of 10% each of the demolition flow tolerance in the case treatment from.

Further is the machining deep grooves in an inner wall of the housing difficult in the axial direction. In addition, there is the problem that the case processing in an impeller in a closed design, for example passing shrouds has, can not be used.

Since there is a need to fluid from the turbomachine directly or on the outside In addition, with such active control, it is impossible to escape efficiency reduction of the turbomachine system as a whole.

to Elimination of the disadvantages of the above-mentioned prior art Therefore, an object of the present invention to provide a turbomachine, not just such a rising behavior on the right Side of the characteristic curve between pressure level and throughput eliminated but it is also capable of reducing the efficiency to suppress, i.e. the vortex generated due to recirculation, the occurs at the inlet of the impeller, as well as the rotational flow separation to suppress.

Especially It is an object of the present invention to provide a turbomachine provide a pressure altitude throughput characteristic without the behavior that it falls off to the right has and with which a high efficiency can be achieved.

Further It is a further object of the present invention to provide a Turbomachine provide, with such a pressure altitude-throughput characteristic without the behavior of the waste on the right as well as a easy production can be achieved.

Besides that is Another object of the present invention is to provide a turbomachine having a closed-type impeller, and with that also such a pressure altitude throughput characteristic without the behavior of a waste on the right side can be achieved can.

• – mit einem Gehäuse, in welchem eine Strömungsfläche gebildet wird,
• – mit einem Laufrad, das eine Vielzahl von Schaufeln aufweist und innerhalb des Gehäuses angeordnet ist und
• – mit einer Vielzahl von Nuten bereitgestellt, die in der Strömungsfläche des Gehäuses für eine Verbindung zwischen der Einlassseite des Laufrads und einem Bereich ausgebildet sind, in welchem die Schaufeln des Laufrads liegen,
• – wobei jede der Nuten eine Breite von wenigstens gleich 5 mm oder mehr hat und die Nuten so ausgebildet sind, dass ihre Breite etwa 30% bis 50% bezüglich einer Gesamtumfangslänge des Gehäuses beträgt, an der die Nuten ausgebildet sind.

To achieve the above-mentioned goal (s), a turbomachine is used

• With a housing in which a flow area is formed,
• - With an impeller having a plurality of blades and is disposed within the housing and
• Provided with a plurality of grooves formed in the flow surface of the housing for communication between the inlet side of the impeller and a region where the impeller blades are located,
• - Each of the grooves has a width of at least equal to 5 mm or more and the grooves are formed so that their width is about 30% to 50% with respect to a total circumferential length of the housing on which the grooves are formed.

at the aforementioned Turbomachine according to the invention the grooves are formed so that their depth relative to the Diameter of the housing is about 0.5% to 1.6%.

at the above-defined turbomachine according to the invention Furthermore the grooves are formed so that they have a depth of about 2 mm 4 mm.

at The turbomachine according to the invention as defined above is the impeller an impeller in an open design with a variety of blades, wherein the floor area Each of the grooves is built so that it is level with the flow area adjacent to the flow surface of the flow housing equal or higher as this is.

at the aforementioned Turbomachine according to the invention the impeller is an open-plan impeller and has a variety of shovels while the flow area of the housing, those with a lower flow adjoins, so formed at a terminal end of each of the grooves is that they are at the same height with the bottom surface of the Groove is located or in a direction of an external diameter from it lies, with the outer peripheral portion of the impeller on the inlet side of its blades a groove portion opposite is designed so that the heights of his Blades the groove portion is correspondingly low, while the Height everyone Blade of the impeller downstream of the grooves is higher than that on the section which is opposite to the groove portion.

at a turbomachine according to the invention defined above, wherein the impeller is an impeller in an open design with a large number of blades is, is the floor area one of each of the grooves designed so that their height is equal or higher as the adjoining flow surface of the housing, during the Outer peripheral portion of Impeller on the inlet side of its blades a groove section opposite designed so that its height the groove portion corresponding to its blades is low.

at the turbomachine according to the invention as defined above, in which the impeller is an open-wheeled impeller with a variety of Shoveling is the height each of the blades on a meridian plane near one Inlet of the impeller is designed so that it is less than on a meridian plane nearby an outlet of the impeller, wherein these heights of the blades of the height of a Nutabschnitts are determined accordingly.

In the above-defined turbomachine according to the present invention, in which the impeller is an open-type impeller having a plurality of blades, there is also an arrangement of flow channels with protruding portions of the Nu is constructed to be larger than that formed in the housing on the downstream side of the grooves, and is extended to the upstream side as it is at a distance in the radial direction from a rotational center of a pump is a tip portion of the Impeller is formed so that it forms an approximately constant space between the grooves and the inner surfaces of the housing, and the height of each of the blades of the impeller in the vicinity of a terminal end of the grooves is formed larger than that of the blades on the downstream side.

at the turbomachine according to the invention as defined above, in which the impeller an impeller in a closed design with a variety of shovels and a shroud around it and the impeller in nearby an inlet of the impeller as an impeller in open design with no shroud is formed around it, the plurality of Grooves in pressure gradient direction on the inner wall of the housing, the near the section Opposite the inlet of the impeller, the no shroud around it, formed on the perimeter and is one Start end of each of the grooves on an inlet side upstream of a Peak inlet side of the impeller arranged while a terminal end of each Nut arranged downstream of a Spitzenauslassseite the impeller is.

at the above-defined turbomachine according to the invention, in which the impeller is an impeller in a closed design with a variety of Shovels and a shroud around them and the impeller in open construction without shroud around it near one Inlet of the impeller is formed, the plurality of grooves a big Number of shallow grooves, in the flow area of the housing an outer peripheral portion of the impeller in an inlet side of its blades opposite are designed to connect between a place where at a low fluid flow rate at an inlet side of the impeller a vortex is generated and an area on the flow surface at the periphery of the housing, at which the blades of the impeller in the direction of the fluid pressure gradient lie to produce; is an end position on a downstream side each of the grooves is arranged to receive a fluid at a pressure which is necessary to the generation of the vortex in the inlet mainstream an end position upstream of each of the grooves to suppress an increasing behavior on the right side of a pressure altitude-throughput characteristic the turbomachine is eliminated; and is a floor surface of each of the grooves is designed so that their height is equal or higher as the adjacent flow area of the Housing, and is the outer peripheral portion of the impeller on the inlet side of its blades a groove portion opposite formed so that the groove portion corresponding height of the blades of the impeller is low.

at the turbomachine according to the invention as defined above is further an axle seal section for a seal between a minimum radial portion of the Shroud of the impeller and the housing provided, wherein the Achsenabdichtabschnitt a mouth ring portion and a housing ring portion.

at the above-defined turbomachine according to the invention, in which an end position on the downstream side of each of the grooves so arranged is that a fluid can be obtained with a pressure required is to keep the vortex at the inlet main flow at an end position on the Current side to suppress each of the grooves, thereby increasing Behavior on the right side of a pressure altitude throughput characteristic of Eliminate turbomachine is a section of the housing, at the grooves are provided, separated from another section formed of the housing.

at The turbomachine according to the invention defined above is the housing with a variety of housing nuts formed, which are divided in its axial direction, and are the grooves on the inner surface a housing lining the outer peripheral portion on the inlet side of the blades of the impeller opposite educated.

at The turbomachine according to the invention as defined above is a section of the housing, on which the grooves are formed, divided and built by a other section of the housing out, which is divided in its radial direction.

at The above-defined turbomachinery according to the invention are the Grooves are formed at their beginning end in a direction of a direction of the pump axis to a direction of rotation of the impeller is inclined.

In the above-defined turbomachine according to the present invention, a directivity number for determining a shape of the grooves is obtained by the following equation: JE No. = WR × VR × WDR × DLDR where WR (a width ratio) is a value obtained by dividing a total value of the groove widths W by a length of the housing periphery,
VR (a volume ratio) is a value obtained by dividing a total volume of the grooves by a volume of the impeller;
WDR (width-depth ratio) is a value obtained by dividing the width W of the groove by a depth D, and
DLDR is a ratio between a length of the groove downstream of the impeller inlet and the depth of the groove and the grooves are formed so that the guideline number JE no. in a range of 0.03 to 0.5.

at The above-defined turbomachinery according to the invention are the Grooves designed so that the guideline JE no. in one area from 0.15 to 0.2.

• – eine Pumpe mit einem Laufrad und einem Gehäuse, in dem das Laufrad zum Hochpumpen des Fluids in die Ansaugseite angeordnet ist;
• – einen Kanal zum Leiten des von der Pumpe zu der Förderseite hochgepumpten Fluids;
• – eine Antriebsvorrichtung für einen Drehantrieb des Pumplaufrads und
• – eine Regeleinrichtung zum Regeln der Drehzahl des Laufrads der Pumpe aufweist, wobei die Pumpe die in Anspruch 1 definierte Pumpe ist.

Moreover, according to the present invention, in order to achieve the above-mentioned object (s), there is provided a pumping station for raising a pumping height of a fluid on a suction side to that on a delivery side, the pumping station

• - A pump with an impeller and a housing in which the impeller is arranged for pumping the fluid into the suction side;
• A passage for guiding the fluid pumped up from the pump to the delivery side;
• - A drive device for a rotary drive of Pumplaufrads and
• - Has a control device for controlling the speed of the impeller of the pump, wherein the pump is defined in claim 1 pump.

According to the present invention there is further provided a pumping station as defined above and wherein a rated speed Ns is about 1000 to 1500 assuming that the speed of the pump used in the pumping station is N (rpm), the total pumping height H (m) and the delivery rate is Q (m ³ / min) and that the rated speed is obtained as a guideline number Ns for displaying a pump characteristic by an equation N ₃ = N × Q ^0.5 / H ^0.75 , and in which a static Pumping height, which is determined by a suction-side fluid level and a delivery-side fluid level, equal to or greater than 50% of the pumping height at a nominal point.

Farther is inventively in the above defined pumping station, the speed of the drive device in a control range of 60% to 100% with respect to a reference speed then regulated when the drive device for the pump is a speed reducer, having a fluid coupling and a diesel engine.

According to the invention will continue in the pump station defined above, the speed of the drive device in a control range of 60% to 100% with respect to a reference speed controlled when the drive device for the pump is a speed reduction gear, comprising a fluid coupling and a gas turbine.

Further is inventively in the above defined pumping station, the speed of the drive device in a control range from 0% to 100% with respect to a reference speed remotely controlled when the drive device for the pump is an electric motor for controlling the speed through an inverter.

BRIEF DESCRIPTION OF THE DRAWINGS

1 FIG. 10 is an enlarged sectional view of a half-axial pump according to a first embodiment of the present invention. FIG.

2 is an example of the effects of the present invention (part 1).

3 is an example of the effects of the present invention (part 2).

4 is an example of the effects of the present invention (part 3).

5 is an example of the effects of the present invention (part 4).

6 FIG. 12 is a meridian plane view of a half-axial pump according to a second embodiment of the present invention. FIG.

7 is a section along the line II-II of 6 ,

8th FIG. 12 is a meridian plane view of (ie, first) the half-axial pump according to the second embodiment of the present invention. FIG.

9 FIG. 12 is a meridian plane view of another (ie second) variation of a half-axial pump according to the second embodiment of the present invention. FIG.

10 Fig. 10 is a surface view of an example of the groove formation in the above second embodiment of the present invention.

11 FIG. 12 is a meridian plane view of another (ie, third) change of the half-axial pump according to the second embodiment of the present invention. FIG.

12 FIG. 12 is a meridian plane view of a closed-type half-axial pump according to a third embodiment to which the present invention is applied. FIG.

13 is a sectional view taken along the line VIII-VIII of 12 ,

14 is a view of the meridian plane of the closed-type Halbaxialpumpe in the form of a (ie first) modification of the third embodiment of the present invention.

15 is a view of a meridian plane of the closed-type Halbaxialpumpe according to another (ie second) modification of the third embodiment of the present invention.

16 is a view in a meridian plane to illustrate the guideline JE no. for determining the configuration of the grooves according to the present invention.

17 is a sectional view taken along the line XII-XII of 16 ,

18 is a diagram for explaining the relationships of the guideline JE no. for determining the configuration of the grooves in the above embodiments with respect to a pumping height instability and a decreasing amount of the maximum efficiency.

19 Fig. 15 is a diagram showing a flow rate pump-up characteristic of the turbomachine of the above embodiments according to the invention of the present invention.

20 shows a block diagram of the scheme of a pumping station, in which the turbomachine according to the present invention is used.

21 FIG. 15 is a graph showing a pump-height displacement characteristic of a half-axial pump in the pumping station of FIG 20 to illustrate their effects.

22 is a sectional view of a Halbaxialpumpe according to the prior art.

23 Fig. 10 is a diagram showing a typical pressure-height-flow rate characteristic of the prior art half-axial pump.

24 (a) and (b) are views for explaining prior art case processing.

25 (a) to (c) are views for explaining separators of the prior art.

DETAILED DESCRIPTION PREFERRED EMBODIMENTS

in the Following are embodiments after of the present invention with reference to the accompanying drawings explained.

1 FIG. 11 is an enlarged sectional view of a first embodiment of the present invention, for example, the one in FIG 22 shown Halbaxialpumpe, and in particular an enlarged view of a part which is enclosed in this figure by a dashed line.

Specifically, in the turbomachine of the present invention, a vortex due to the reverse flow at the blade inlet is suppressed by having shallow grooves together with an inclination of the fluid pressure (ie, the pressure gradient) 124 on the flow surface of the housing 121 formed from a central portion "a" (ie, an end position of the groove on the downstream side) of the blade 122 extend to a position "b" (ie, an end position of the groove on the upstream side) where the recirculation occurs at a low flow rate.

Then, the fluid, the pressure of which is increased by the blades, starts in the opposite direction in the grooves 124 directed to flow from the end position "a" on the downstream side to the end position "b" on the upstream side and is injected or sprayed into the location or the place where the recirculation occurs at low flow rate, whereby the formation of the vortex due to the recirculation as well the rotational flow separation of the impeller is prevented.

2 For example, Fig. 1 is an illustration showing the effect of the present invention (part 1), particularly, the effect by forming the grooves. In 6 to 9 the horizontal axis shows the fluid flow rate and the vertical axis the pumping height, both sizes dimensionless.

The white Circles show the characteristic of pump height / flow rate in case that no groove in the housing is formed, where there is still such a behavior with a Rise or jump on the right after the increase of the Throughput in a range of 0.12 to 0.14 of the dimensionless Throughput can be seen.

White triangles or white Squares show the characteristics of pump height / throughput, in particular for the Cases, in which the grooves in the housing are formed, with the white ones Triangles for the Case stand that 28 grooves (N = 28), for example, with a width 5 mm and a depth of 4 mm, while the white Squares show the case in which also 28 grooves formed but with a width of 10 mm and a depth of 2 mm.

Out 2 it follows that the increase ver can not be solved or excluded on the right side in the case in which the grooves are formed with a width and depth of 5 × 4 mm, but completely dissolved in the case in which the grooves with a width and length of 10 × 2 mm are formed. This shows that shallow and wide grooves are more effective than those which get a greater depth in their formation. 2 However, it also shows that, although the efficiency η theoretically decreases due to the fluid backflow in the channels, it is so small that it is practically undetectable.

3 For example, Fig. 4 is an illustration showing another effect of the present invention (part 2), particularly the influence of the length of the grooves.

Especially the efficiency / flow rate characteristic is shown when the end position "a" on the downstream side is changed, while the end position "b" on the power side on the condition that the form or design the grooves remain almost the same, the characteristic is better i.e. the rising behavior on the right side is the lower is, the lower the end position "a" is the downstream side is. However, if they are too extreme on the downstream side is the efficiency decreases, because too much high-pressure fluid, ie more than necessary, is deducted.

4 For example, Fig. 4 is an illustration showing another effect of the present invention (Part 3), particularly the influences of depth and width.

you sees that if the groove or the number of grooves kept constant The depth does not have much impact on the pump height / flow rate characteristic has, but the bigger the Width is the better the pump height / flow rate characteristic, i. the rise behavior on the right side will be.

5 For example, Fig. 4 is an illustration showing another other effect of the present invention (part 4), particularly the influences of the depth and the width of the grooves.

you sees that when the grooves in their design or with their Profile are kept the same, the pressure head / throughput curve, i.e. the rise ratio on the right side, the better the larger the number of grooves.

• 1. Die Position "a" der Nut an der Endposition auf der Stromabseite sollte nicht auf eine spezielle Position beschränkt werden, insbesondere soweit sie in einer Position liegt, in der das Fluid daraus abgezogen werden kann, das unter einem solchen Druck steht, dass es die Erzeugung des Wirbels aufgrund der Rezirkulation unterdrücken kann, die an der Endposition "b" auf der Stromaufseite der Nuten durch Einspritzen auftritt, es muss jedoch eine geeignete Stelle ausgewählt werden, da der Wirkungsgrad der Turbomaschine abnimmt, wenn sie sich in einer Position befindet, in welcher der hohe Druck größer als erforderlich ist.
• 2. Es besteht keine Notwendigkeit, die Tiefe der Nut zu vergrößern, es ist jedoch sehr wirksam, eine große Anzahl von Nuten auszubilden, die eine Breite haben, die so groß wie möglich ist.

From this, the following aspects can be enumerated that come into consideration when designing the grooves.

• 1. The position "a" of the groove at the end position on the downstream side should not be limited to a specific position, particularly so far as it is in a position in which the fluid can be withdrawn therefrom, which is under such a pressure that it however, the generation of the vortex due to the recirculation occurring at the end position "b" on the upstream side of the grooves by injection can be selected, but an appropriate place must be selected because the efficiency of the turbomachine decreases when it is in a position, in which the high pressure is greater than required.
• 2. There is no need to increase the depth of the groove, but it is very effective to form a large number of grooves having a width as large as possible.

By various experiments carried out by the inventors of the present invention has shown that the width (W) of the above-mentioned grooves and the number (N) of them preferably in a range of about 30% to 50% of the total circumferential length of the housing are selected, in which the protruding grooves are formed (i.e., π × D, if D is the diameter in a part of the case is where the protruding grooves are formed). Although the depth (d) of them preferably about 2 mm to 4 mm in the above embodiment is, if the diameter (D) of the housing about 250 mm, it follows that the ratio of the depth (d) of the grooves in terms of the diameter of the housing adjusted to a range of about 0.5% to 1.6% (d / D = 0.5% to 1.6%) should be.

When next a second embodiment of the present invention will be explained in more detail. at the turbomachine according to the second embodiment of the present invention Invention become flows or channels for connection between a location at the inlet of the impeller, where recirculation takes place when throughput is low, and an area on the flow area of the housing provided in which the blades of the impeller in the gradient direction the fluid pressure to the vortex due to the recirculation at the inlet of the impeller and to suppress the rotational stall.

In such a construction, in the flow channels communicating between a downstream end position in the area where the blades are located on the flow surface of the housing and an upstream end position where the recirculation occurs when the flow rate is low, fluid flows in the opposite direction from the downstream end position back to the upstream end position so that it is injected into the place where the recirculation takes place when the throughput is low. As a result, a part of the fluid, the pressure of which flows through was raised in the opposite direction in the flow channels formed on the housing to be injected at the point where the recirculation occurs, whereby the generation of the vortex due to the forward component (ie, the component parallel to the Haupteinlassströ tion) Recirculation is suppressed at the impeller inlet. Therefore, it is possible to exclude the rising behavior on the right side in the pump-height-throughput characteristic of the turbomachine.

If However, as mentioned above is built, the cutting process of the grooves is difficult, which is below accomplished becomes. The grooves are namely provided in the direction of the main gradient of the fluid pressure, and the simplest configuration or form is a straight line, being a center line of the groove is aligned in the axial direction in alignment. However, the grooves are on the inner wall (i.e., the flow surface) of the housing on the opposite side of the wheel Side provided and designed so that it from the housing wall sunk from. If you try such grooves with a tool Machining must, since the edges of the grooves at both ends (i.e., the upstream and downstream sides) in the form of sack ends, the tool can be stopped at the ends when cutting in by moving the tool along the center line of the groove he follows. Therefore, disadvantages come into consideration that the efficiency The machining is extremely reduced that for the cutting Processing a lot of time is required and that this will increase the Production costs leads.

• (1) Die Bodenfläche der Nut wird an die Höhe der Fläche der Gehäuseinnenwand (d.h. die Strömungsfläche) so angepasst, dass auch dann kein Problem auftritt, wenn das Werkzeug über das Ende der Nut während des spanenden Bearbeitungsprozesses der Nut hinausgeht. Die Schaufel wird in einer Stufenform ausgeführt, bei der sich die Höhe der Schaufel, die den Höhen der Nuten von dem den Nuten gegenüberliegenden Teil entspricht, von denen des den Nuten nicht gegenüberliegenden Teils unterscheidet, so dass sie dem konvexen Abschnitt der Nuten entspricht.
• (2) Der Gehäuseteil, in dem die Nuten ausgebildet werden, ist von dem anderen Teil/den anderen Teilen getrennt. Durch Vornahme des getrennten Aufbaus ist es möglich, die Nuten leicht spanend zu bearbeiten.

To improve these aspects, the following is proposed according to the present invention:

• (1) The bottom surface of the groove is adjusted to the height of the surface of the housing inner wall (ie, the flow surface) so that no problem occurs even if the tool goes beyond the end of the groove during the machining process of the groove. The bucket is carried out in a step shape in which the height of the bucket corresponding to the heights of the grooves from the part opposite to the grooves differs from that of the part not facing the grooves so as to correspond to the convex portion of the grooves.
• (2) The housing part in which the grooves are formed is separated from the other part (s). By performing the separate construction, it is possible to easily machine the grooves.

Around the turbomachine, which has a pumping height throughput characteristic without has a sleeper on the right, even one Turbomachine to obtain an impeller in a closed design with a shroud around it, the following is suggested.

The Shroud is removed only on the blade part at which the recirculation occurs in the inlet section of the impeller in a closed design, while it is maintained downstream so as to have the impeller so that it has the shroud around it. On a part of the housing inner wall is in the direction of the pressure gradient relative to the part of the impeller without circumferential shroud formed the plurality of grooves.

below become concrete embodiments of the present invention with reference to the attached Drawings closer explained.

6 shows an example of the second embodiment of the present invention. In 7 is a sectional view II-II of 6 shown.

On an inner wall 2a (ie the flow area) are when the flow channel of the housing 2 has an impeller in an open design, especially in a Halbaxialpumpe, the grooves formed in the axial direction. The groove is with a convex part 3a with a height D from the inner wall 2a of the housing protrudes, and with a concave section 3b built with a height equal to that of the inner wall 2a is. The width (W) and the number (N) are for example about D / W = 0.05 to 0.3 or N = 25 to 100. For example, in the pump with an impeller diameter of 300 mm to 4500 mm, the width ( W) about 5 mm to 150 mm, and more preferably 8 mm to 30 mm, while the height (depth) of the grooves about 0.1 to 0.3 times the width of the corresponding grooves, for example about 0.5 mm to 30 mm, more preferably about 1.5 mm to 6 mm. The blade of the impeller is made in such a shape in height that a distance δ at the blade tip for the normal impeller can be maintained in an open design, in particular in the form on the meridian plane, the convex portion of the grooves on a stationary side contains.

When the pump is operated in this construction in the low flow area, the fluid whose pressure has been increased by the blades flows in the groove 3 returning it from the end position "a" on the downstream side to the end side "b" on the downstream side, and is injected at the position of recirculation occurring when the flow rate is low, whereby generation of the vortex due to the forward component the recirculation at the point where the recirculation occurs is prevented. As a result, the pumping height / flow rate characteristic is from the right side Increasing section freed, so that there is a stable curve without the rising behavior on the right side. The above-mentioned construction has the advantage that the production of the grooves can be carried out easily. The reason for this is that the convex section 3a the grooves extend from the wall surface 2a extends at the end of the groove and that further the concave portion 3b the grooves are located at the same height of the wall surface at the end, whereby the tool at the end edge of the grooves during their processing can continuously pass through, in particular in the machining process, so that the efficiency of the machining can be improved.

A (first) modification according to the second embodiment of the present invention is in 8th shown. In this example, the housing is 2 on the stationary side with a housing lining having the grooves 2c and with stationary housing nuts 2d and 2e provided without the grooves, wherein the stationary-side housing lining 2c . 2d and 2e are arranged as separate elements in the axial direction. In this construction, the cutting formation of the grooves 3 only on the case chuck to be provided with such grooves, as a part, while the end edge portion of the grooves is open, whereby the efficiency of the machining can be further improved.

Another (second) modification of the second embodiment of the present invention is in 9 shown. In this example, the housing is 2 on the stationary side also with a grooved, stationary housing lining 2c built while the stationary-side housing lining 2d and 2f have no grooves, wherein the stationary-side housing lining 2c is executed with the grooves as a separate element that of the stationary-side housing lining 2f divided without grooves in the radial direction. Also in this example, only the housing with the grooves as a part in the machining of the grooves 3 are machined, and the end edge portion of the grooves is open, whereby the efficiency of the machining can be further improved.

An example of the configuration of the grooves according to the second embodiment of the present invention is shown in FIG 10 shown. In this example, a beginning end of the groove 3 , located on the downstream side of the impeller 1 is inclined only at an angle θ in the direction of rotation of the impeller from the direction of the pumping axis. With such a structure, in the low flow area where the instability in the pump height / flow characteristic occurs, the recirculation, ie, the return flow from the impeller on the upstream side, is caused by the grooves 3 , in particular a circulating component thereof, suppressing, whereby the vortex component in the main flow flowing in the impeller is reduced. Accordingly, the pump-up flow rate characteristic which can theoretically provide the impeller is not lowered, so that a stable pump-height flow rate characteristic can be achieved. However, at the flow rate near the closing point, the return flow of the recirculation reaches the upstream side further than the above-mentioned recirculation range. However, the direction of the grooves at this point is not in the direction of the pump axis, but is inclined at the angle θ in the direction of rotation of the impeller. Thereby, the return flow, which reaches the vicinity of the output end of the grooves, a vortex component in the direction of the grooves granted, ie. In the direction of rotation of the impeller, and by this return flow, the vortex component is also given a small amount of fluid flowing into the impeller. Thus, the pump-height flow rate characteristic which can theoretically provide the impeller drops as compared with the case where the grooves are formed parallel to the pump axis, and accordingly, an axial motive power consumed for rotating the impeller also drops , which results in a reduction of the axial movement performance for closing. In this way it is with the embodiment of in 10 shown grooves, not only to achieve the stability of the pumping height conveying performance characteristic, but also to achieve a reduction of the axial movement performance for the closing, thereby obtaining a Halbaxialpumpe with superior properties.

Another (third) modification according to the second embodiment of the present invention is in 11 shown. In this example, further processing is performed as compared with the above-mentioned examples, resulting in the following improvements. In particular, in the embodiment on the meridian surface, the convex portion 3a the groove 3 made larger than the configuration of the flow channel of the stationary housing housing 2f without the grooves extending into the existing suction side at a distance in the radial direction from the center of rotation of the pump. The configuration of the tip of the impeller (ie, the shape on the shroud side) that faces the part of the grooves is set so that suitable openings or spaces between the grooves 3 in each case on the stationary housing lining 2c and between the stationary housing lining 2f be formed. Specifically, in the meridian plane flow channel, each blade of the impeller is constructed so that its height on the downstream side near the end "a" of the groove is smaller by δ2 than on the upstream side. If the turbomachine of this construction is operated in the low flow range, the fol advantages are obtained. In the low-flow area where the instability in the pump-height flow rate characteristic occurs when no groove is formed, the recirculation occurs 4 in the flow, as it is in 11 is shown. In this case, because of the presence of the above-mentioned step-shaped portion δ2, the recirculation becomes 4 interrupted by the stepped portion on the tip side of the blade, whereby its penetration into the downstream side is prevented. Thus, in such a pump mentioned above, since the return flow starts from a large flow rate, the decrease in the unstable part of the pumping height flow rate characteristic becomes small, whereby the stabilization of the pumping height flow rate characteristic can be realized much more. In particular, the instability of the pump-height flow rate characteristic can be reduced even in the case where no grooves 3 are formed, as well as in the case in which the grooves 3 are provided, and the instability of the pump-height flow rate characteristic (ie, the rising behavior on the right side of the pump-height flow rate characteristic) can be securely excluded. Further, the convex portion becomes 3a , the end of the output 3b the groove 3 forms, executed in a tilted direction. This exit end 2 B is provided near the portion where the flow channel out of the portion parallel to the axis of the housing 2 is guided in the direction of the outer diameter.

When next becomes a third embodiment explains in which the present invention in a Halbaxialpumpe in closed Construction used.

12 shows an example of the present invention, during 13 Section VIII-VIII of 12 shows.

At the closed wheel 1 the half-axial pump is a shroud going around it 1a intended. This shroud 1a is near the inlet 1c the impeller is not provided, for which the impeller is an impeller in half-open design, which has the shroud partially. At the very inside diameter of the shroud is a mouth ring section 1b and a housing ring portion on an inner surface of the housing on the stationary side 5 intended. Between the mouth ring section 1b and the housing ring portion 5 is a sealing portion of the rotation axis 3 educated. On the inner wall (ie the flow area) 2a of the housing is on the stationary side opposite the blades at the portion where no shroud is provided around, as in FIG 13 shown a variety of grooves 3 formed, which are aligned at the same distance in the axial direction. The end a on the downstream side of the groove is located slightly at an entry position in the downstream side from the front edge of the blade (ie, the position adjacent to the mouth portion near the inlet 1c the impeller) while its end position b on the downstream side is further upstream than the blades of the impeller. A section 2g of the housing 2 , the one end surface 1d of the shroud of the impeller is provided in the position which is the same as the downstream end position a of the groove 3 in the axial direction. The surface 2g of the housing 2 in a direction perpendicular to its axis and the end surface 1d of the shroud are arranged with the opening δ1 in the axial direction therebetween.

If the pump is operated with such a construction in the low flow range, occurs as in 12 shown, the recirculation, ie the return current, on. Part of the stream 6 flows in the reverse direction in the grooves 4 from the downstream end position a to the upstream end position b, however, since the grooves are formed in the axial direction of the pump, the return flow flowing in the grooves has no component rotating in the rotational direction of the impeller. Thereby, the return current flowing in the grooves is injected to the upstream side in the place where the recirculation 6 occurs at a low flow rate, whereby the generation of the vortex due to the forward component of the recirculation at the inlet of the impeller and the generation of a rotational flow break can be suppressed. Namely, the vortex component in the recirculation fluid, which flows backward upstream, is weakened by the current injected from the grooves, so that the vortex in the fluid flowing into the impeller becomes small. Therefore, the reduction of the theoretical pumping height is small, whereby the stability in the pumping height flow characteristic is achieved.

In the present embodiment, since it is possible to suppress the vortex in the fluid flowing into the impeller by means of a small amount of fluid passing through the groove 3 flows, the pumping height, which theoretically can be derived by the impeller, is increased, and the pumping-height conveying capacity characteristic can be freed from the unstable portion, whereby its stability is achieved. In the present embodiment, it is also possible with the closed-end impeller with the shroud around it, the stability of the pumping height flow characteristic by providing the grooves 3 in the case 2 to achieve, that is, the pumping height flow characteristic shows a continuously decreasing on the right side behavior, so that it is possible to obtain a pumping characteristic that is stable.

14 shows a (first) modification of the third embodiment of the present invention. The housing 2 is with the housing nuts 2c . 2d and 2e built, which are divided in the axial direction, and the grooves 3 are in the case lining 2c formed, which is provided at the inlet portion of the impeller. The grooves 3 are the same as in the respective examples mentioned above. After this example it is also possible to use the grooves 3 easy to make with the help of the tool, as the grooves 3 are open at both ends.

15 shows another (second) modification of the third embodiment of the present invention. The housing 2 is with the housing nuts 2c . 2d . 2e and 2f provided, which are divided in the axial direction. Furthermore, the housing lining 2c and 2f divided in the radial direction. The grooves 3 are in the case lining 2f formed on the inner diameter side, which is provided at the inlet portion of the impeller. In this example, the grooves become 3 also in the same embodiment as in the respective aforementioned examples. As in this example, the housing lining 2f in which the groove 3 is formed smaller than the one in 14 shown part 2c can be performed, it is thus possible, the grooves 3 easier to cut using the tool.

Even though the explanation for one Semi-axial pump in a closed design in the above-mentioned embodiments The present invention can also be applied to other turbomachinery come to the application, such as a centrifugal pump, a Semi-axial fan, one Halbaxialkompressor etc., whereby each machine an impeller in open Construction or closed construction may have.

Based on 16 to 19 Next, a preferred embodiment of the grooves 3 the respective examples explained.

On the basis of different test results one has the design of the grooves 3 investigated, which are preferred in that the rising behavior on the right side in particular in the pressure altitude-throughput characteristic of the turbomachine excluded and the drop in efficiency is suppressed. There is the following guide number (hereinafter referred to as "JE No.") which relates to a suitable configuration of these grooves.

The guideline number JE no. can be defined by the following equation: JE No. = WR × VR × WDR × DLDR where WR is a width ratio in the form of a value obtained by dividing a total value of the groove widths W by a circumferential length of the housing. Therefore, WR = (number of grooves N x groove width W) / (average circumferential length of the housing at the portion where the grooves are formed), wherein the average circumferential length of the housing, for example, by reference to 16 to π × (inlet diameter of the case Dc1 + outlet diameter of the case Dc2 / 2) can be obtained.

VR is a volume ratio in the form of a value obtained by dividing a total volume of the grooves by a volume of the impeller. Thus, VR = total volume of the grooves / volume of the impeller. The total volume of the grooves can be obtained here by the number of grooves N × groove length L × groove width W × groove depth D, while the volume of the impeller results from inlet area of the impeller × axial direction length of the tip of the impeller Li. The inlet area of the impeller is obtained from the inlet diameter Dil of the impeller. The groove length L is in 16 L1 + L2.

WDR is a width-depth ratio and results in WDR = groove width W / groove depth D.

DLDR is a ratio between a length of the groove and its depth downstream of the impeller inlet, and results in DLDR = groove length L1 downstream of the impeller tip / groove depth D with reference to FIG 17 ,

18 shows the test results using the above JE No. In the figure, the horizontal axis JE no. The vertical axis on the left shows the pumping height instability (%) and is defined by the following equation indicating an amount reduced at the unstable portion of the pumping-height flow rate characteristic and a ratio between the decreasing amount ΔΨ ₀ when no groove is formed. and the decreasing amount ΔΨ when the grooves are formed. Pumphoe instability (%) = (ΔΨ / ΔΨ 0 ) × 100

Each of the decreasing amounts ΔΨ and ΔΨ ₀ is obtained as in 19 is shown from a difference between the maximum value and the minimum value in the unstable portion (the portion showing the rising behavior on the right side) of the pump-height-throughput characteristic. ΔΨ is a finite value if the instability is in the pump height (ie showing the rising behavior on the right side), on the other hand it is zero (0) if there is no such instability in the pressure level (ie if no such ascending behavior on the right side shows). Accordingly, this means that the unstable Ab The pump-height-flow rate curve is completely different due to the function of the grooves when the pump-height instability is at 0%, while no effect is obtained from the grooves and then no improvement in instability can be achieved when the pump-height instability occurs 100% lies. When the pumping height instability is between 0% and 100%, it means that the instability of the pumping height is not completely extinguished, but the unstable portion is improved by the grooves to a certain extent.

The vertical axis in 18 right shows the decreasing amount (%) of the maximum efficiency and means the difference of the maximum efficiency (%) between the states when grooves in the pump and when no grooves are provided. The value is 0%, if there is no change in the maximum efficiency of the pump between the states with and without grooves, it has a positive value if the decrease in efficiency occurs by providing the grooves, for example, 3% means that the decrease of 3 % efficiency in providing grooves occurs.

According to 18 Based on the above explanations, the pump height instability exceeds 80% in the characteristic when JE no. is equal to or smaller than 0.03, then the effect of the grooves becomes abruptly small. If JE No. is close to 0.03, the pumping height instability is improved to about 30%, and if it exceeds 0.03, the pumping height instability is further improved. If JE No. is more or less 0.15, the instability is 0%, ie you can see that instability ceases. If JE No. 0.15, the pump height instability is stable since it is 0%. With a view to achieving the stability of the pumping heights, JE no. preferably equal to or greater than 0.03. From the point of view of efficiency in 18 the decreasing amount of the maximum efficiency is 0% or less until JE no. to 0.15 more or less comes. However, if it exceeds 0.15, the decreasing amount of the maximum efficiency becomes large relative to this JE No. Assuming that an acceptable amount of decrease in efficiency due to the provision of the grooves is up to 1%, JE no. preferably equal to or less than 0.5. Therefore, from the viewpoints of both the pump height stability and the efficiency, it is preferable for JE No. to set a suitable range of 0.03 to 0.5, and particularly useful is JE No. between 0.15 and 0.2 as the state for complete resolution of instability, but decrease in efficiency.

In the 18 For example, test results shown apply to the pump at a speed of 830, but similar results are also obtainable in the case where similar tests are performed on 1250 and 1400 speeds. Therefore, it can be seen that the configuration of the grooves by using JE no. in the form of the above guide number at least in the speed range of 800 to 1400 can be determined. It is also contemplated that the configuration of the grooves may also be made using JE no. for speeds from 300 to 2000 can be determined.

To the invention flows a part of the fluid, the pressure of which has been increased, back into a flow channel, in the case is designed to be injected at the point where the recirculation occurs, i. the flow without turbulence from the grooves suppresses the vortex component in the Backflow, which is returned by the impeller and the recirculation forms so that no vortex is generated in the fluid which flows into the impeller the generation of the vortex due to recirculation at the inlet of the impeller and a rotational flow separation repressed which makes it possible is the ascending behavior on the right side in the pump-height-throughput characteristic to exclude the turbomachine.

With the subdivided structure of the housing and in providing the grooves on the housing lining according to Inlet portion of the impeller can according to the invention has an effect be achieved that the turbomachine are carried out so can make that the machining of the grooves are easily performed can, that sets almost no reduction in the efficiency and that the pumping height flow rate characteristic is stable.

It is according to the invention also possible with a turbomachine, the one impeller of closed construction with walking shroud has, by running the impeller as a semi-open structure without shroud on the section near of the inlet and providing the grooves on the inner wall surface (i.e. the flow area) of the housing in the direction of the pressure gradient corresponding to the section of the impeller to make the turbomachine easy, with its pumping height flow characteristic is stable, even if it works at low throughput, where the Recirculation occurs, and in the turbomachine almost no loss in the efficiency occurs.

By Determining the configuration of the grooves by using the guide number, i.e. JE No., lets yourself as well achieve an effect that the embodiment is particularly useful in that that stability the pumping height conveying capacity characteristic can be easily achieved.

In the enclosed 20 is a block in a pumping station in which the invention is used, for example as a dewatering pump in a dewatering pumping station instead of the water circulation pumps in thermal power plants or nuclear power plants, as mentioned above.

The pumping station has a pump 200 , For example, the Halbaxialpumpe, are formed in the flat grooves in the housing corresponding to the impeller, in particular in the portion at the inlet. The impeller of the pump is mounted on an axis of rotation by means of a drive device (or drive) 210 set in rotation, which has, for example, a diesel engine, a gas turbine, an electric motor, etc.

The rotational speed or speed of the drive device 210 is from a pump speed controller 220 controlled, which is provided for this purpose, for example, with an electrical circuit unit or a microcomputer unit. As shown by the dashed connection, if necessary, a vane angle control device is still provided 230 provided to adjust the angle of inclination of the blades of the impeller depending on the change in flow rate of the fluid flowing into the impeller.

The pump 200 with the above construction has a bell mouth 210 floating in the water in an intake sump or canal 240 dips, and a production pipe or a pipe 250 that with a donation sump or a canal 260 is connected at a distance from the suction sump or intake. By the operation of the above-mentioned pumping station, the pumping height of the water, ie, the suction water level, becomes the discharge water level in the discharge sump or channel 260 increased or increased, including the flow resistance in the fluid flow channel, ie in the delivery pipe 250 ,

at the pump, the main one is designed in terms of efficiency, consists of the Assuming that the maximum throughput is 100%, the tendency that the rising behavior on the right in part of the Pump head-capacity curve noticeable, in particular from 50% to 70% in throughput, whereby the operation of the pump brought into an unstable state will, or alternatively, that, even if no such rise behavior On the right side, to a considerable extent arises, the pumping height flow rate characteristic but also in the range of 50% to 70% of throughput a part becomes flat.

Of the Operating flow rate of the pump of the pumping station is in one place that determines an intersection between a static pumping height, the as the difference between the water pressure levels or levels on the suction side and the funding side in the pumping station is determined, a resistance curve through Sum up the resistance in the flow channel or in the tubes is determined in the pumping station, and the pumping height conveying capacity characteristic curve the pump forms. If a rising on the right side area at the pumping height conveying capacity characteristic is present, the case may occur that the pumping height flow characteristic the resistance curve intersects at several points. In this case is it impossible to determine the point of intersection in only one place, i. the throughput can not be uniquely determined, which is why the throughput is not can be determined. In particular, this is significant if the stationary one Pump height big and the Pipe resistance is small.

Therefore can in the prior art then when the maximum efficiency and the stability of pumping height be brought into equilibrium to the pumping height capacity curve without to get ascending behavior on the right side, the case occur that the maximum efficiency drops only slightly. alternative becomes in the case where the unstable area in the pump is present, the pump is controlled so that it is only in the range operated in which no such unstable operation occurs, by a rule of operation for the pump is set up. Accordingly, in the pumping station, with which the operating range is controlled by the speed of the pump The speed is controllable or restricted only within the range it is in the stable range, i. not in the unstable Area occurs. Thus, if operation is related to the speed (i.e. Turning speed) into the unstable area for one unit of the pumps must, becomes a measure to the effect that the number of pumps is increased, thereby reducing the delivery rate for every Pump is low and so the operating point of each pump to a Point outside of the unstable area is moved.

at a method for achieving the stability of the pumping height conveying performance curve, in which to a certain extent In the prior art, the maximum efficiency is geop fert, it follows, because the efficiency is slightly reduced due to the stable pumping range will, a problem for that the consumption of electrical energy increases. In the process, wherein the operating points of each of the number of pumps increased is moved so that it avoids the unstable operating area, There are also problems that the system and the control process are complex and the costs increase.

Therefore, according to the invention, a pump in which the rotational speed can be changed in a wide range by using the half-axial pump having a pump-high flow rate characteristic without such rising behavior on the right side and capable of achieving higher efficiency; resulting in a pumping station that can operate in a wide flow range.

The Essence of the present invention is that in the pumping station, in which the operating range of the pump is controlled by its speed the pump used in the pumping station is the half-axial pump is where any of the housings is used, which has the above-mentioned grooves.

In the above-mentioned pumping station, effects can be obtained, particularly when a specific rotation speed Ns is set to be about 1000 to 1500, assuming that the rotation speed of the half-axial pump used in the pumping station is N (rpm) ), the total pumping height H (m) and the delivery rate Q (m ³ / min), and that the specific speed Ns as a benchmark for indicating the pump characteristic by the equation N s = N × Q 0.5 /H 0.75 and when a static pumping height determined by an intake water level and a delivery water level is equal to or greater than 50% of the pumping height at a specific point.

The Essence of the present invention lies in the fact that the speed of the pump in a control range of 60% to 100% with respect to one Reference speed controlled in a case can be controlled in which a drive device for the pump is a speed reduction gear, having a fluid coupling and a diesel engine. The speed can also be in the tax range of 60% to 100% in terms of Reference speed can be controlled in the case in which the drive device for the Pump a reduction gear, a fluid coupling and a gas turbine having. Furthermore has the drive device for The pump has an electric motor that controls the speed through an inverter controls. In this case, the speed may be in the control range of 0% to 100% re the reference speed can be controlled.

21 Fig. 14 shows an example of the pumping height conveying performance characteristic of the pump of the pumping station, which has one of the above-mentioned half-axial pumps according to the present invention. In 21 the horizontal axis shows the flow rate through the ratio of% throughput% Q assuming that a discharge flow rate as a reference is 100%, while the vertical axis indicates a pumping height ratio% H assuming a total discharge pumping height as a reference at 100% lies. In 21 shows a pump altitude curve 10 A characteristic of an example of the half-axial pump according to the present invention, when the reference speed is 100% N, and shows a tendency of the drop on the right side over the entire area, so that no unstable area is present. On the other hand, the pump height curve shows 14 a characteristic at 100% N in a case where the present invention is not applied and the instability is more or less 50% Q, that is, in this case, the unstable range is in a range of 40% Q to 70% Q , The resistance curve 18 is a characteristic of the present pumping station. When the pump is operated at 100% N, the point of intersection lies between the pump altitude curve 10 and the resistance curve 18 or between 14 and, which is only one point, ie the point A, so that in any case the pump can be stably operated at point A. Considering the case where the rotational speed is lowered to 90% N for the reduced-throughput operation, the stable pump-up curve will be established according to the law of similarity, which will be discussed later 10 the pump down to a pumping height curve 11 shifted while the unstable pump altitude curve 14 down to a pump altitude curve 15 is moved.

The law of similarity is: Q2 = Q1 × (N2 / N1) H2 = H1 × (N2 / N1) 2 where Q is the flow rate, H is the total pumping height, N is the rotational speed and the additive 1 is the rotational speed state N1 and the additive 2 is a rotational speed state n2.

The operating point in this case is the point B, so that the pump can stably operate stably regardless of the unstable range in the pump altitude curve. When the rotational speed is further reduced to 74% N, the pumping height curve becomes after the above-mentioned similarity law 10 having no such instability according to the present invention, down to a pump altitude curve 12 shifted, with the intersection between the resistance curve 18 only one point, namely the point C, ie the operating point lies in the point C. On the other hand, the pump altitude curve 14 , which has the instability, down to a pump altitude curve 16 shifted at 74% N, being nearly parallel to the resistance curve 18 near 30% Q to 50% Q is. Therefore, the intersection of the pump altitude curve 16 with the resistance curve can not be determined at any point, but there can be a multitude of intersections between them. Accordingly, the throughput point can not be uniquely determined, so that the operation of the pump fluctuates in the instability range from 30% Q to 50% Q on the pump altitude curve and is not controllable, so that the operation between 30% Q and 50% Q is not performed can.

When the speed is further reduced to 60% N, the pumping height curve becomes 10 , which according to the invention has no instability, down to the pumping height curve 13 shifted while the pump altitude curve 14 with the instability down to the pump altitude curve 17 is moved. When reducing by then, the intersection between the resistance curve becomes 18 determined in only one point, ie the point D, for each case of the pump altitude curves 13 and 17 , so that the operation of the pump is possible.

in the Case of the characteristic curve exhibiting instability in the prior art, as mentioned before However, the pump can range from 30% Q to 50% Q at the Speed 74% N do not work. The area where the pump is working can, then becomes discontinuous. Therefore, the pump speed is between 74% N and 100% N in the range, and the operating range the pump is between point A and point C.

on the other hand can the Halbaxialpumpe according to the present invention stable at operate at a speed equal to or less than that mentioned, so that the operation over the wide range of throughput from point A to point D. can.

In the present embodiment, the driving device for the pump has the speed reduction gear, the fluid coupling and the diesel engine, the operation being from the point A to the point D as shown in FIG 21 is shown possible, when the control range for the speed is 60% to 100% relative to the reference speed. Another drive device for the pump has the speed reduction gear, the fluid coupling and the gas turbine, the operation from the point A to the point D, as in 21 is possible, when the control range of the speed is 60% to 100% with respect to the reference speed. Another driving device has the electric motor that controls the rotational speed by the inverter, wherein the operating range is widened when the control range of the rotational speed is 0% to 100% with respect to the reference rotational speed. This is the case because the speed is up to a point near the point E in 21 can be lowered, so that the operation of the pump in the range of nearly 0% Q up to 100% Q is possible.

By Using the improved pump of the present invention can, since the efficiency hardly drops, while the pumping height-conveying performance curve can be stably maintained at the Halbaxialpumpe, the pumping station be obtained, in which the range of speed greatly expanded and the operation is easily carried out in a wide range of throughput can.

Claims (22)

Turbomachine with a housing ( 121 ), in which a flow surface is formed, an impeller, which has a plurality of blades ( 122 ) and disposed within the housing, a plurality of grooves ( 124 ) formed in the flow surface of the housing to communicate between an inlet side of the impeller and a region where the impeller blades are located, characterized in that each of the grooves has a width of at least 5 mm or greater, and the grooves are formed so that their width is 30% to 50% with respect to a total circumferential length of the housing on which the grooves are formed. Turbomachine according to claim 1, characterized that the grooves are formed so that their depth relative to the Diameter of the housing approximately 0.5% to 1.6%. Turbomachine according to claim 2, wherein the grooves are formed so that their depth is about 2 mm to 4 mm. Turbomachine according to claim 1, wherein the impeller an open-plan wheel that has a variety of blades has, and a bottom surface each of the grooves is formed so that its height is equal to or higher, as the adjacent flow area of the Housing. Turbomachine according to claim 1, wherein the impeller an open-plan wheel that has a variety of blades and the flow area of the housing downstream of an end of completion of each of the grooves thus formed is that they are at the same height with the bottom surface of each groove is located or diametrically out of half lies, the outer peripheral portion of the impeller on the inlet side of its blades a groove portion opposite is designed so that the height its blades corresponding to the groove portion is low while the Height everyone Blade of the impeller downstream of the grooves is higher than the one on the section the groove section opposite lies. Turbomachine according to claim 1, wherein the Impeller is an open-type impeller having a plurality of blades, and wherein a bottom surface of each of the grooves is formed so that its height is equal to or higher than the flow area of the housing adjacent thereto, and the outer peripheral portion of the impeller on the Inlet side of its blades a groove portion opposite is formed so that its height corresponding to the groove portion is low on its blades. Turbomachine according to claim 1, wherein the impeller an open-plan wheel that has a variety of blades and at the height each of the blades on a meridian plane near one Inlet of the impeller is formed so that it is less than on a meridian plane nearby an outlet of the impeller, and these heights of the blades of the height of one Nutabschnitts are determined accordingly. Turbomachine according to claim 1, wherein the impeller an open-plan wheel that has a variety of blades and in which as well a Configuration of a formed with protruding portions of the grooves flow channel is constructed so that it is larger as the ones in the case is formed on the downstream side of the grooves, and in the Stromauseite, as it is, at a distance in the radial direction from a center of rotation extended a pump is a tip portion of the impeller is formed so that he approximates one constant space between the grooves and the inner surfaces of the housing forms, and the height each of the blades of the impeller near a terminal end of the Grooves formed larger is as the shovel on the downstream side. Turbomachine according to claim 1, wherein the impeller a closed-wheel impeller that has a variety of Shovels and a shroud arranged around it, and at the impeller nearby an inlet of the impeller, around which no shroud is arranged, is designed in an open design, and also the multitude of Grooves in one direction of a pressure gradient on the inner wall of the housing on its circumference the section near the inlet of the impeller, around which no shroud is provided, is formed opposite, and a starting end of each of the grooves on an inlet side upstream is arranged from a tip inlet side of the impeller while a Terminating end of each groove downstream of a tip outlet side of the impeller is arranged. Turbomachine according to claim 1, wherein the impeller a closed-wheel impeller that has a variety of Shovels and a shroud arranged around it, and at the impeller nearby an inlet of the impeller, around which no shroud is arranged, is designed in an open design and also the multitude of Grooves a big one Number of shallow grooves, which in the flow area of the housing an outer peripheral portion the impeller formed on an inlet side of its blades opposite are to connect between a place where at a low Fluid flow on an inlet side of the impeller generates a vortex is, and an area on the flow area at the periphery of the housing to the blades of the impeller in the direction of the pressure gradient of Fluids lie, manufacture, an end position on a downstream side each of the grooves is arranged to receive a fluid at a pressure which is necessary to the generation of the vortex in the inlet main flow on an end position upstream of each of the grooves to suppress an increasing behavior on the right side of a pump-height-throughput characteristic the turbomachine is eliminated, and a floor area of each of the grooves is formed so that its height is equal to or higher, as the adjacent flow area of the housing, and the outer peripheral portion the impeller on the inlet side of its blades opposite a groove portion is formed so that the groove portion corresponding height of the blades of the impeller is low. Turbomachine according to claim 9 or 10, further comprising a Axle seal section for sealing between a minimum radial Section of the shroud of the impeller and the housing has, wherein the Achsdichtabschnitt a Mundringabschnitt and a Gehäuseringabschnitt having. Turbomachine according to claim 1, wherein an end position downstream of each of the grooves is arranged so that a fluid with a pressure that is necessary to the vortex in the inlet mainstream at an end position upstream of the grooves to suppress an increasing behavior on the right side of a pump-height-throughput characteristic the turbomachine is removed, and a section of the housing, at the grooves are provided, separated from another section of the housing is trained. Turbomachine according to claim 12, wherein the housing with formed a plurality of housing nuts which are divided in its axial direction and the grooves on the inner surface a housing lining the outer peripheral portion on the inlet side of the blades of the impeller opposite are formed. Turbomachine according to claim 12, wherein a section of the housing, on which the grooves are formed, is divided and constructed of another section of the housing is mounted, which is divided in its radial direction. Turbomachine according to one of claims 4 to 14, in which the grooves are formed at their initial end in one direction are that of a direction of the pump axis to a direction of rotation of the impeller is inclined. A turbomachine according to claim 1, wherein a directivity number for determining a shape of the grooves is obtained by the following equation: JE No. = WR × VR × WDR × DLDR where WR (a width ratio) is a value obtained by dividing a total value of the groove widths W by a length of the casing periphery, VR (a volume ratio) is a value obtained by dividing a total volume of the grooves by a volume of the impeller, WDR (width-depth ratio) is a value obtained by dividing the width W of the groove by a depth D, and DLDR is a ratio between a length of the groove downstream of the impeller inlet and the depth of the groove, and the grooves are so are trained that the guideline JE no. in a range of 0.03 to 0.5. Turbomachine according to claim 16, wherein the grooves are designed so that the guideline number JE no. in one area from 0.15 to 0.2. Pumping station for raising a pumping height of a Fluids on a suction side on the on a delivery side, with a pump, an impeller and a housing in which the impeller is arranged to the fluid in the Pump suction side, a channel for guiding the pump to the production side pumped up fluids, a drive device for a rotatable drive of the impeller of the pump, and a control device for controlling the speed of the impeller of the pump, the pump the pump defined in claim 1. A pumping station according to claim 18, wherein a rated speed Ns is about 1,000 to 500, assuming that the speed of the pump used in the pumping station is N (rpm), a total pumping height H (m), and a delivery rate Q (m ³ / min), and that the rated speed is obtained as a guideline for indicating a pump characteristic by an equation N _s = N × Q ⁰ ' ⁵ / H ^0.75 , and in which a static pumping height represented by a suction-side fluid level and a delivery-side Fluid level is determined equal to or greater than 50% of the pump height at a nominal point. Pumping station according to claim 18, wherein in one case in which the drive device for the pump is a speed reducer, a fluid coupling and a diesel engine, a rotational speed of the drive device in a control range of 60% to 100% with respect to a reference speed is regulated. Pumping station according to claim 18, wherein in one case in which the drive device for the pump is a speed reducer, a fluid coupling and a gas turbine comprises, a rotational speed of the drive device in a control range of 60% to 100% with respect to a reference speed is regulated. Pumping station according to claim 18, at the reference speed in a case where the drive device for the pump an electric motor for controlling the speed through an inverter comprises, a rotational speed of the drive device in a control range from 0% to 100% re a reference speed is controlled.