JP2003227497A - Variable casing treatment device and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable casing treatment device and its control method which increases a stall margin, delaying stall occurrence of a compressor and secures a stable operation area of the compressor without decreasing operation efficiency at a normal operating point. <P>SOLUTION: The device is equipped with a variable treatment mechanism 10, a measuring device 20 for an amount of state and a control device 30. The variable treatment mechanism 10 openably and closably shuts up a plurality of long grooves 2 installed at an inner surface of the casing 1 surrounding a moving blade 3 of an axial flow compressor and the measuring device 20 for an amount of state measures an amount of state of flow in the axial flow compressor. The control device 30 controls the variable treatment mechanism by detecting predicting signal of stall occurrence based on the amount of state. The groove 2 is in the closing state at the normal operation time and a casing treatment is formed by opening the groove 2 when detecting predicting signal of stall occurrence. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable casing treatment device and its control method.

[0002]

2. Description of the Related Art In an axial compressor, a casing treatment for forming a groove shape in a casing is sometimes used in order to widen its operation area. As shown in FIG. 5 (A), the casing treatment is to form a groove 2 on the inner wall of the casing 1 and to withdraw the low energy fluid that triggers the occurrence of stall to the groove so that the flow in the mainstream portion is sound. It delays the occurrence of stall. The groove 2 constituting the casing treatment includes a circumferential groove shown in FIG. 5 (B), an axial groove shown in FIG. 5 (C),
Also, an oblique groove (not shown) may be used. In this figure, 3 is a rotor blade of the axial flow compressor.

[0003]

By forming the casing treatment described above, the stall margin of the axial compressor can be improved up to about 20% at the maximum, but on the other hand,
It is known that operating efficiency decreases. That is, although the casing treatment has an effect of delaying the occurrence of stall, it has a problem of lowering the operating efficiency at an operating point where the effect is not required. In particular, if the treatment groove is deepened, the effect of delaying stall generation increases, but the amount of decrease in operating efficiency tends to increase. For this reason, the application of the treatment remains within the range in which the reduction in the operating efficiency is acceptable, and there is a problem that the effect of the treatment cannot be sufficiently exerted.

The present invention was created to solve such problems. That is, the present invention provides a variable casing treatment device capable of increasing the stall margin, delaying the stall of the compressor, and ensuring a stable operation region of the compressor without lowering the operating efficiency at the normal operating point and its control. To provide a method.

[0005]

According to the present invention, a variable treatment mechanism for opening and closing a plurality of elongated grooves (2) provided in an inner surface of a casing (1) surrounding a moving blade (3) of a compressor. (10), a state quantity measuring device (20) for measuring the flow state quantity in the compressor, and a control device (30) for detecting a stall occurrence sign based on the state quantity and controlling the variable treatment mechanism, There is provided a variable casing treatment device characterized in that the groove is closed during normal operation, and the groove is opened to form a casing treatment when a stall occurrence sign is detected.

According to the above configuration of the present invention, the variable treatment mechanism (10) does not close (block) the plurality of elongated grooves (2) provided on the inner surface of the casing (1) and has no groove. The form in which the groove is opened to form the casing treatment can be switched at any time. Also,
The state quantity measuring device (20) measures the flow state quantity in the compressor, detects the stall occurrence sign based on the state quantity measured by the control device (30), controls the variable treatment mechanism, and during normal operation, Since the groove is closed, it is possible to prevent a decrease in operating efficiency at the normal operating point. When a sign of stall occurrence is detected, the groove can be opened to form a casing treatment to delay stall occurrence of the compressor and secure a stable operation region of the compressor.

According to a first preferred embodiment of the present invention,
The variable treatment mechanism (10) includes a plurality of arcuate ring segments (12A) that are radially movably housed in a plurality of circumferential grooves (2A) that extend in the circumferential direction and that are divided in the circumferential direction. A plurality of biasing devices (14) for biasing each of the ring segments radially outward, and a ring member (16) surrounding the plurality of biasing devices, the circumferential direction of the ring member (16). Due to the movement, during normal operation, each ring segment is pressed inward in the radial direction to form a surface with the groove closed, and when a stall occurrence sign is detected, the ring segment is moved outward by the biasing force. Forming a casing treatment with said groove open.

According to the structure of the first embodiment, during normal operation, the ring members (16) surrounding the plurality of biasing devices are moved in the circumferential direction to press each ring segment (12A) radially inward. Since the circumferential groove (2A) is closed, the operating efficiency at the normal operating point can be prevented from lowering. When a sign of stall occurrence is detected, the ring member (16) is moved in the circumferential direction to move the ring segment (12A) outward by the biasing force to form the casing treatment with the groove open. Thus, the stall of the compressor can be delayed and a stable operation region of the compressor can be secured.

According to a second preferred embodiment of the present invention,
The variable treatment mechanism (10) includes a plurality of rod-shaped rod segments (12B) housed in a plurality of axial grooves (2B) extending in the axial direction so as to be movable in the radial direction, and the rod segments radially outside. A plurality of urging devices (14) for urging toward one side and a ring member (16) surrounding the plurality of urging devices are provided, and by the circumferential movement of the ring members (16), each of them is operated in normal operation. The rod segment is pressed inward in the radial direction to form a flat surface with the groove closed, and when a sign of stall occurrence is detected, the rod segment is moved outward by the biasing force, and the casing treatment with the groove opened. To form.

According to the configuration of the second embodiment described above, during normal operation, each rod segment (12B) is pressed inward in the radial direction by the circumferential movement of the ring member (16) surrounding the plurality of biasing devices. In addition, it is possible to prevent a decrease in operating efficiency at the normal operating point by providing the surface having the groove closed. Further, when a sign of stall occurrence is detected, similarly, the circumferential movement of the ring member (16) causes the rod segment to move outward by the biasing force to form a casing treatment with the groove open, It is possible to delay the occurrence of stall in the compressor and secure a stable operation region of the compressor.

The state quantity measuring device (20) is a thin film sensor for detecting a flow velocity or a pressure sensor for detecting a pressure. With such a thin film sensor and a pressure sensor, it is possible to measure a flow state quantity such as a flow speed fluctuation or pressure fluctuation inside the compressor.

According to the present invention, a variable treatment mechanism (10) for opening and closing a plurality of elongated grooves (2) provided on the inner surface of a casing (1) surrounding a moving blade (3) of a compressor is provided. A variable casing treatment device including a state quantity measuring device (20) for measuring a flow state quantity in a compressor, and a control device (30) for detecting a stall occurrence sign based on the state quantity and controlling a variable treatment mechanism. And a state quantity measuring step (A) of measuring a flow state quantity such as a flow speed fluctuation or a pressure fluctuation inside the compressor by the state quantity measuring device (20).
The controller (30) analyzes the flow state quantity and detects a stall sign detection step (B) for detecting flow separation or a stall sign phenomenon, and the groove (2) is closed in a normal time when the stall sign is not detected. To the variable treatment mechanism (10), and when a sign of stall is detected, an "open" control signal is transmitted to the variable treatment mechanism (10) to open the groove (2). Control signal transmitting step (C) and a return signal for retransmitting a "closed" control signal to the variable treatment mechanism (10) so as to close the groove (2) when the operating state of the compressor returns to the normal state. A method of controlling a variable casing treatment device, characterized in that it comprises a transmitting step (D).

According to the above method of the present invention, the flow state quantity is measured in the state quantity measuring step (A), the flow separation or the stall precursor phenomenon is detected in the stall sign detecting step (B), and the control signal transmitting step (C). ), The control signal of "open" or "closed" is transmitted to the variable treatment mechanism (10). In a normal state in which the sign of stall is not detected, the variable treatment mechanism (10) is operated by the “closed” control signal so as to close the plurality of elongated grooves (2) provided on the inner surface of the casing (1) so as to be flush with each other. In this respect, it is possible to prevent a decrease in operating efficiency. Further, when the sign of stall is detected, the variable treatment mechanism (10) is operated by the "open" control signal to open the plurality of elongated grooves (2) provided on the inner surface of the casing (1), and the casing treatment is performed. Can be formed to delay the occurrence of stall in the compressor, increase the stall margin, and secure a stable operation region of the compressor. Further, when the operation state of the compressor returns to the normal state in the return signal transmitting step (D), the “close” control signal is retransmitted to the variable treatment mechanism (10) so as to close the groove (2) again. By operating the variable treatment mechanism again to return the treatment groove to the closed state, it is possible to avoid a decrease in operating efficiency in the normal state.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, in each figure, the same parts are denoted by the same reference numerals.

FIG. 1 shows the principle of the variable casing treatment device of the present invention. In this figure, the variable casing treatment device of the present invention comprises a variable treatment mechanism 10, a state quantity measuring device 20, and a control device 30.
Equipped with. The variable treatment mechanism 10 is configured so as to openably and closably close a plurality of elongated grooves 2 provided on the inner surface of the casing 1 surrounding the moving blades 3 of the axial compressor by a drive device (not shown). The groove 2 may be a circumferential groove, an axial groove, or an oblique groove.

The state quantity measuring device 20 is, for example, a thin film sensor for detecting a flow velocity or a pressure sensor for detecting pressure. The thin film sensor is formed on the surface of the moving blade 3 of the axial compressor as illustrated in FIG. 1, and the flow velocity data of the moving blade 3 is transmitted to the control device by a slip ring or a telemeter. This thin film sensor includes, for example, Japanese Patent Application No. 5-22.
The "air flow state detection sensor" disclosed in No. 8807 can be used.

The pressure sensor is, for example, a piezoelectric conversion element attached to the casing 1, and is adapted to detect the pressure fluctuation of the casing 1. In the present invention, both the thin film sensor and the pressure sensor may be used together, or only one of them may be used to measure the flow state quantity in the axial compressor.

The control device 30 is, for example, a control computer or a PC (personal computer), and the state quantity (flow velocity fluctuation, pressure fluctuation) detected by the state quantity measuring device 20.
Based on the above, the variable treatment mechanism 10 is controlled by detecting a stall occurrence sign. The detection of the stall occurrence sign can be performed by a well-known algorithm based on the flow velocity fluctuation, the pressure fluctuation, and the like.

Using the variable treatment mechanism 10 described above, the control method of the present invention uses the state quantity measuring step (A),
The stall sign detection step (B) includes a control signal transmission step (C) and a return signal transmission step (D).

In the state quantity measuring step (A), the state quantity measuring device 20 measures the flow state quantity such as the speed fluctuation or pressure fluctuation of the flow inside the compressor. In the stall sign detection step (B), the control device 30 analyzes the measured flow state quantity and detects a flow separation or a stall sign phenomenon.

In the control signal transmitting step (C), at the normal time when the stall sign is not detected, a "close" control signal is sent to the variable treatment mechanism 10 so as to close the groove 2 flush, and when the stall sign is detected. Sends an "open" control signal to the variable treatment mechanism 10 to open the groove 2. In the return signal transmitting step (D), when the operating state of the compressor returns to the normal state, the “close” control signal is retransmitted to the variable treatment mechanism 10 so as to close the groove 2 again.

FIG. 2 is a characteristic diagram of an axial flow compressor equipped with the variable casing treatment device of the present invention.
In this figure, the horizontal axis is the gas flow rate of the axial compressor, and the vertical axis is the pressure ratio and efficiency. The solid line in the figure shows the case where there is no groove (casing treatment) at the same rotation speed, and the broken line shows the case where there is a groove. As is clear from FIG. 2, with the casing treatment, the stall margin of the axial compressor is improved to a lower flow rate, but on the other hand, the operating efficiency in the normal operation line is reduced. That is, although the casing treatment has the effect of delaying the occurrence of stall, it can be seen that the operating efficiency at the operating point where the effect is not required decreases.

In the apparatus and method of the present invention, as shown by a double-headed arrow in the figure, the case where there is no groove (casing treatment) and the case where there is a groove are switched. That is, according to the configuration of the present invention, the variable treatment mechanism 10
Thus, it is possible to switch between a form in which the plurality of elongated grooves 2 provided on the inner surface of the casing 1 are not closed (closed) and a form in which the casing treatment is formed by opening the grooves.

That is, according to the apparatus and method of the present invention,
The state quantity measuring device 20 measures the flow state quantity in the axial flow compressor, detects the stall occurrence sign based on the state quantity measured by the control device 30, and controls the variable treatment mechanism.
At the time of normal operation, the stall margin can be increased without decreasing the operating efficiency at the normal operating point by taking the form in which the groove is closed (the form without the groove). That is, without treatment (on the solid line in FIG. 2), the operating limit is approached,
When the sign of stall occurrence is detected, the groove is opened to form the casing treatment, and the groove is present (Fig. 2).
It is possible to delay the occurrence of stall in the compressor and secure a stable operation region of the compressor.

FIG. 3 is a first embodiment of the variable casing treatment device of the present invention. In this figure,
FIG. 1A is an embodiment diagram of a portion A in FIG. 1, and FIG. 1B is a BB arrow view thereof.

In FIG. 3, the variable treatment mechanism 1
0 comprises a plurality of arcuate ring segments 12A, a plurality of biasing devices 14 and a ring member 16.

The plurality of arcuate ring segments 12A are
A plurality of circumferential grooves 2A extending in the circumferential direction are housed so as to be movable in the radial direction, and the entire ring divided in the circumferential direction forms a ring. Each ring segment 12A
Has an inner surface formed in the same arcuate surface as the inner surface of the casing 1, and is dimensioned so as to be flush with the inwardly moved position in the drawing.

Each of the plurality of urging devices 14 has a rod 14a having an inner end fixed to each ring segment 12A and extending outward in the radial direction, and a flange 14b having an arcuate head fixed to the outer end of the rod 14a. , And a compression spring 15 that urges the collar portion 14b outward, and urges each ring segment 12A outward in the radial direction.

The ring member 16 is a ring-shaped member that surrounds the plurality of biasing devices 14, and the inner surface 16a thereof corresponds to the circumferential spacing of the biasing devices 14 and is smoothly uneven inward and outward in the radial direction. It has a face. By moving the ring member 16 in the circumferential direction by a driving device (not shown), contact between the uneven surface (inner surface 16a) and the arc-shaped collar portion 14b
At the time of normal operation, each ring segment is moved inward in the radial direction to form a flat surface with the circumferential groove 2A closed, and when the sign of stall occurrence is detected, the ring segment is compressed.
5 moves outwards to form a casing treatment with open circumferential groove 2A.

Therefore, according to the configuration of the first embodiment described above, the ring member 1 surrounding the plurality of biasing devices during normal operation.
By moving the ring segments 6 in the circumferential direction, the ring segments 12A are pressed inward in the radial direction so as to form a flat surface in which the plurality of circumferential grooves 2A are closed, and thus it is possible to prevent a decrease in operating efficiency at the normal operating point. When the stall occurrence sign is detected, the ring segment 16 is moved by the movement of the ring member 16 in the circumferential direction.
A can be moved outward by the biasing force to form a casing treatment in which the groove is opened, and the stall generation of the compressor can be delayed to secure a stable operation region of the compressor.

FIG. 4 is a diagram of a second embodiment of the variable casing treatment device of the present invention. In this figure,
FIG. 1A is an embodiment diagram of a portion A in FIG. 1, and FIG. 1B is a BB arrow view thereof.

In FIG. 4, the variable treatment mechanism 1
0 comprises a plurality of rod-shaped rod segments 12B, a plurality of biasing devices 14 and a ring member 16. The rod-shaped rod segments 12B are housed in the axial grooves 2B extending in the axial direction so as to be movable in the radial direction. The inner surface of each rod segment 12B is formed in the same arcuate surface as the inner surface of the casing 1, and is dimensioned so as to be flush with the position shown in the drawing when moved inward.

Each of the plurality of biasing devices 14 has a rod 14a having an inner end fixed to each rod segment 12B and extending outward in the radial direction, and a flange 14b having an arcuate head fixed to the outer end of the rod 14a. , And a compression spring 15 that urges the collar portion 14b outward, and urges each rod segment 12B outward in the radial direction.

The ring member 16 is a ring-shaped member similar to that shown in FIG. 3, and its inner surface 16a is provided with smooth uneven surfaces inward and outward in the radial direction corresponding to the circumferential spacing of the biasing device 14. ing. The ring member 16 is driven by a driving device (not shown).
By moving in the circumferential direction, the uneven surface (inner surface 16a)
When the ring segment is in normal operation, each ring segment is pressed inward in the radial direction by the contact between the ring segment and the brim portion 14b, and the groove is closed to form a flat surface. The segment is moved outward by the biasing force to form the grooved casing treatment.

Therefore, according to the configuration of the second embodiment described above, the ring member 1 that surrounds the plurality of biasing devices during normal operation.
By moving the rod 6 in the circumferential direction, the rod segments 12B are pressed inward in the radial direction, and the groove is closed to form a uniform surface, so that a decrease in operating efficiency at the normal operating point can be prevented. Further, when a sign of stall occurrence is detected, the rod segment is similarly moved outward by the biasing force by the circumferential movement of the ring member 16 to form a casing treatment with the groove open, and the compressor is compressed. It is possible to delay the occurrence of stall and secure a stable operation region of the compressor.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0037]

As described above, according to the present invention, the groove formation of the casing treatment is a variable mechanism, the groove is normally closed, and the measuring instrument installed inside the compressor allows
Only when a sign of stall occurrence such as flow separation is detected, the variable mechanism is activated to form the groove, which delays the stall occurrence of the compressor as compared with the case where no treatment is applied, and at the same time the normal operating point. Now close the groove,
The operation efficiency is maintained at the same level as that in the case where the treatment is not applied, and the decrease in efficiency is avoided.

That is, the variable casing treatment device and its control method of the present invention increase the stall margin, delay the occurrence of stall in the compressor, and reduce the stable operation region of the compressor without lowering the operating efficiency at the normal operating point. It has an excellent effect that it can be secured.

[Brief description of drawings]

FIG. 1 is a principle view of a variable casing treatment device of the present invention.

FIG. 2 is a characteristic diagram of an axial-flow compressor equipped with the variable casing treatment device of the present invention.

FIG. 3 is a first embodiment of a variable casing treatment device according to the present invention.

FIG. 4 is a second embodiment view of the variable casing treatment device of the present invention.

FIG. 5 is an explanatory view of a conventional casing treatment.

[Explanation of symbols]

1 casing, 2 groove, 2A circumferential groove, 2B axial groove, 3 moving blade, 10 variable treatment mechanism, 12A
Ring segment, 12B Rod segment, 14
Urging device, 14a rod, 14b collar part, 15 compression spring, 16 ring member, 16a uneven surface (inner surface),
20 state quantity measuring device, 30 control device,

Continued front page    F term (reference) 3H021 AA01 BA11 BA20 CA00 CA01                       CA03 CA07 DA09 EA05 EA12                 3H034 AA01 AA02 BB03 BB08 CC04                       DD05 DD26 DD30 EE08 EE15

Claims (5)

[Claims] 1. A variable treatment mechanism (10) for opening and closing a plurality of elongated grooves (2) provided in an inner surface of a casing (1) surrounding a moving blade (3) of the compressor, and a flow state in the compressor. A state quantity measuring device (20) for measuring the quantity,
A control device (30) for detecting a stall occurrence sign based on the state quantity and controlling the variable treatment mechanism is provided, and the groove is closed during normal operation, and the groove is formed when the stall occurrence sign is detected. A variable casing treatment device, which is opened to form a casing treatment. 2. The variable treatment mechanism (10).
Is a plurality of arcuate ring segments (12A) which are housed in a plurality of circumferential grooves (2A) extending in the circumferential direction so as to be movable in the radial direction and which are divided in the circumferential direction, and each of the ring segments in the radial direction. A plurality of biasing devices (1
4) and a ring member (16) surrounding the plurality of biasing devices, and by the circumferential movement of the ring member (16), each ring segment is pressed inward in the radial direction during normal operation. The groove is closed to form a flush surface, and when a stall occurrence sign is detected, the ring segment is moved outward by the biasing force to form a casing treatment in which the groove is opened. 1. The variable casing treatment device according to 1. 3. The variable treatment mechanism (10).
Is a plurality of rod-shaped rod segments (12B) housed in a plurality of axial grooves (2B) extending in the axial direction so as to be movable in the radial direction, and a plurality of rod-shaped rod segments (12B) for urging the rod segments radially outward. A biasing device (14) and a ring member (16) surrounding the plurality of biasing devices.
6) By the circumferential movement of 6), during normal operation, each rod segment is pressed inward in the radial direction to form a flat surface with the groove closed, and when a sign of stall occurrence is detected, the rod segment is moved outward by the biasing force. 2. The variable casing treatment device according to claim 1, wherein the variable casing treatment device moves towards one side to form an open casing treatment. 4. The variable casing treatment device according to claim 1, wherein the state quantity measuring device (20) is a thin film sensor that detects a flow velocity or a pressure sensor that detects a pressure. 5. A variable treatment mechanism (10) for opening and closing a plurality of elongated grooves (2) provided in an inner surface of a casing (1) surrounding a moving blade (3) of the compressor, and a flow state in the compressor. A state quantity measuring device (20) for measuring the quantity,
A method of controlling a variable casing treatment device, comprising: a control device (30) for detecting a stall occurrence sign based on the state quantity and controlling a variable treatment mechanism, the method comprising: a state quantity measuring device (20); State quantity measuring step (A) for measuring the flow state quantity such as flow speed fluctuation or pressure fluctuation of the flow of the above, and the controller (30) analyze the flow state quantity, and detect flow separation or stall precursory phenomenon. In the stall sign detection step (B) and in a normal time when the stall sign is not detected, a "close" control signal is transmitted to the variable treatment mechanism (10) so as to close the groove (2), and when the stall sign is detected. , A variable treatment mechanism (1 to open the groove (2)
Control signal transmission step (C) for transmitting an "open" control signal to 0), and when the operating state of the compressor returns to the normal state, the variable treatment mechanism (10) is arranged to close the groove (2). And a return signal transmission step (D) for retransmitting a "closed" control signal.