JPH0816479B2 - Surge prevention device for compressor - Google Patents

Description

The present invention relates to a gas turbine or industrial compressor, and is particularly suitable when it is necessary to avoid operating in an unstable operating region of the compressor such as surging. The present invention relates to a surging prevention device for a compressor.

[Conventional technology]

Axial flow type or centrifugal type compressors may enter unstable operation called surging depending on the operating conditions. Since the surging phenomenon involves large pressure fluctuations and flow velocity fluctuations, it increases blade vibrations and shaft vibrations, and in extreme cases, may lead to blade damage accidents. As an example of conventional techniques used to prevent surging, refer to the method described in the book "Blower and Compressor" (Takefumi Ikui, published by Asakura Shoten on July 15, 1972) p365-p358. explain. FIG. 2 shows the general characteristics of a conventional compressor. In Fig. 2, curves 1, 2 ... 4 show the characteristics of the flow rate and the discharge pressure when the compressor speed is constant, and the broken line 5 shows the surge line. In the turbo compressor, the right side of the broken line 5 is the stable operation region, but in the left side region, the surging, turning stall, etc. occur, so that the stable operation of the compressor cannot be performed. Therefore, a surging prevention control device for the compressor is required to monitor and control so as not to enter such an unstable operation range.

FIG. 3 shows the configuration of a turbo compressor provided with a surging prevention device which has been conventionally used. A suction pipe 7 is connected upstream of the compressor 6, and a discharge pipe 8 is connected downstream thereof. The discharge pipe 8 is connected to a branch pipe 9 having a blowoff valve 10. In the configuration of FIG. 3, the characteristic map of the compressor 6 obtained in advance by a preliminary test is stored in the storage device 14. Discharge pressure detector 11 and flow rate detector 12 of the compressor 6
The output from is led to the arithmetic unit 13. The output from the arithmetic unit 13 is guided to the blow-off valve control unit 15, and the operating point of the compressor 6 is stored in the storage unit 14 according to the characteristic map of the compressor.
A comparison is made to determine whether it is in the stable range or the unstable range. When the compressor is used while changing its operating point, the blow-off valve is set to 10 when the compressor operating point reaches from the stable region of the compressor to the unstable region.
Open and control to stay in the stable operating range. In this way, it is possible to prevent the entry into the surging area.

[Problems to be solved by the invention]

The method according to the above-mentioned known technique is effective when the characteristic map of the compressor is constant, but the characteristic map often changes with the passage of time. That is, when deposits such as dust accumulate on the blade surface, the performance of the compressor deteriorates, and the “surge line (before performance deterioration)” shown by the solid line in FIG. 4 is shown by the broken line “surge line (performance deterioration)”. After), the stable operation range becomes narrower. Therefore, when the characteristic map at the initial stage of compressor installation is used as the criterion, it is necessary to widen the margin area A as shown in FIG. Therefore, the conventional method has a problem in that the stable operation range is narrowed down and the surge point prediction accuracy is deteriorated.
Further, generally, the efficiency of the compressor shows the highest value in the region close to the surge line, but in the conventional method in which the surge margin region A has to be wide as described above, the compressor is operated at an operating point where the compressor efficiency is low. There was also a problem.

The present invention has been made based on the above-mentioned matters, and an object thereof is to perform highly accurate surge prediction control irrespective of deterioration of the performance of the compressor over time and to achieve high performance of the compressor.

[Means for solving problems]

In the compressor having a plurality of rows of stationary blades arranged inside the casing, and a row of rotating blades arranged between the rows of stationary blades, (a) detecting an inlet pressure of the compressor. The inlet pressure detector for detecting the inlet temperature of the compressor, (b) the inlet temperature detector for detecting the inlet temperature of the compressor, (c) the outlet pressure detector for detecting the outlet pressure of the compressor, and (d) the outlet temperature of the compressor. A discharge temperature detector for detecting, (e) a flow rate detecting means for detecting a suction flow rate of the compressor, (f) a rotation speed detector for detecting a rotation speed of the compressor rotor, (g) the inlet pressure detector , Inlet temperature detector, discharge pressure detector, discharge temperature detector, flow rate detector, output signal of rotation speed detector, power ratio to constant pressure ratio or suction flow rate at constant correction speed, or constant correction speed Pressure ratio or suction flow rate An arithmetic unit for calculating the power equivalent amount change rate, and (h) a limit value for performing surging determination by comparing the calculated value of the power change rate or the power equivalent amount change rate calculated by the arithmetic unit. (I) The calculated value exceeds the limit value and power (equivalent amount)
And a control device for controlling the operation state of the compressor so that the rate of change does not become 0.

The object is also to provide a compressor having a plurality of stationary blade rows arranged inside a casing and a rotating blade row arranged between the stationary blade rows, wherein (a) an inlet pressure of the compressor is Inlet pressure detector for detecting, (b) Inlet temperature detector for detecting inlet temperature of compressor, (c) Discharge pressure detector for detecting discharge pressure of compressor, (d) Discharge temperature of compressor (E) A flow rate detecting means for detecting the suction flow rate of the compressor, (f) a rotation speed detector for detecting the rotation speed of the compressor rotor, and (j) an inlet of the compressor. Division position pressure detector that detects the pressure at the compressor division position set between the discharge section and the discharge section, (k) a division position temperature detector that detects the temperature at the compressor division position, and (l) the above Dividing position flow rate detecting means for detecting the flow rate at the compressor dividing position, and (m) the inlet Output signals of the pressure detector, inlet temperature detector, discharge pressure detector, discharge temperature detector, flow rate detector, rotation speed detector, split position pressure detector, split position temperature detector, split position flow detector For each of a plurality of split-stage compressors configured with the compressor split position as a boundary, calculate the power change rate or power equivalent amount change rate of each split-stage compressor with respect to at least one of each pressure ratio or suction flow rate. And (n) for each of the split-stage compressors, a limit value for performing surging determination by comparing the calculated value of the power change rate or the power equivalent amount change rate calculated by the calculation apparatus. And (o) compressing at least one of the split stage compressors so that the calculated value does not exceed the corresponding limit value and the power (equivalent amount) change rate becomes 0. By providing a controller for controlling the operating state is achieved.

[Action]

According to Oyama's “Surge Compressor Research,” which will be described later, in a compressor operating at a fixed correction speed, the slope of the compressor characteristic curve expressed by the corrected flow rate and pressure ratio, and the constant power The point where the slope of the line (or the constant line of power equivalent) matches is the surge point. However, the value of maximum power (or maximum power equivalent) cannot be determined without the compressor plunging into surging. Further, when the blade row performance deteriorates due to a long-term operation, it is practically difficult to set the value in advance.

Therefore, the present invention focuses on the power change rate (or the power equivalent change rate). Looking at the intersection of the characteristic curve of the compressor at the modified speed and the constant power line (or the constant power equivalent line), the constant power value increases from the low pressure ratio point to the surge point, and after the surge point. descend. In other words, looking at the relationship between the pressure ratio and the constant power value (the constant power equivalent value), there is an extreme value at the surge point. Therefore, the power change rate ΔL for the pressure ratio change Δπ is ΔL /
Δπ = 0.

Therefore, in the present invention, the above-mentioned various detectors (a)
The computing device (g) calculates the power change rate using the detected values of (b), (c), (d), (e), and (f), and this power change rate is
By controlling the control device (i) so that it is within the limit value stored in the storage device (h), optimum operation is possible regardless of deterioration over time. The same applies to the invention regarding the split stage compressor.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

First, the principle of the present invention will be described. FIG. 5 is a characteristic diagram of a normal compressor. Unlike FIG. 2 described above, in FIG. 5, the vertical axis represents the pressure ratio π of the compressor, the horizontal axis represents the corrected flow rate,
The corrected rotation speed is used as the rotation speed of the parameter. The defining equations for pressure ratio π, corrected flow rate, and corrected rotation speed are as follows.

π = P _d / P _s (1) Where P _d : Compressor discharge pressure P _s : Compressor inlet pressure T _s : Compressor inlet temperature G: Compressor flow rate n: Compressor rotation speed T ₀ : Compressor inlet reference temperature P ₀ : Compressor inlet reference Pressure Generally, the characteristics of the compressor are the compressor input pressure P _s and the inlet temperature T
_Although it is affected by _s, if the characteristics are organized using the pressure ratio π, the corrected flow rate, and the corrected rotational speed as parameters as described above, the effect of the compressor inlet state can be corrected. That is, the fifth
If the map is arranged as shown, the compressor characteristics will not be affected by the inlet condition. This is theoretically derived from the idea that if the Mach numbers related to the axial flow velocity and the peripheral velocity are constant, the flow in each part of the compressor becomes similar.

The surge point on the characteristics of the compressor can be found in the article by Oyama, "Study on Compressor Surge" (Proceedings of the Japan Society of Mechanical Engineers, Vol.
No. 3810-3817), it is said that the maximum power is exhibited in the characteristics of a compressor with a constant correction speed in the case of a multi-stage axial flow compressor or a compressor with a high pressure ratio. In the above document, the maximum value of (π-1) ×, which is a considerable amount, is used instead of the power (see FIG. 6) to compare with the surge point experimentally obtained from various compressors. . As a result, the surge points of both agree with each other with high accuracy. Thus, it can be said that the surge determination criterion that the surge point is the point at which the power or the power equivalent amount is maximum on the compressor characteristics at a constant corrected rotation speed is highly accurate. However, the maximum power or maximum power equivalent cannot be determined without the compressor actually plunging into surging. Further, since these values change due to deterioration of the blade cascade performance over time, it is practically difficult to perform surging determination from the maximum value of power or power equivalent. Therefore, if the power change rate or the power equivalent change rate is used as the surge determination criterion on the compressor characteristics instead of the power or the power equivalent amount, the point where these change rates become zero is the surge point. As described above, if the power change rate or the power equivalent change rate is used as a criterion for surging, it is possible to perform highly accurate surge prediction regardless of the deterioration of blade cascade performance. Moreover, since it is not necessary to provide an unnecessarily large surge margin, a highly efficient high performance compressor can be constructed.

Next, a method of calculating the power change rate on the compressor characteristics at a constant corrected rotation speed will be specifically described. As an example, pressure ratio π
The change rate (dL / dπ) of the power L with respect to is taken up. Every time the pressure ratio changes by the change amount (Δπ) stored in advance, the inlet temperature T _{s of} the compressor, the discharge temperature T _d , and the flow rate G are measured,
The compressor power L is calculated by the following formula.

L = G · Cp · (Td -Ts) · ηad ... (4) _{Here, C p = f (T s} , T d) is the specific heat at constant pressure.

If the pressure ratio and power before and after the pressure ratio changes by Δπ are respectively π ₀ , π and L ₀ , L, the rate of change (dL / dπ) can be calculated by the following equation.

In the above example, the method of calculating the power change rate with respect to the pressure ratio has been described, but the power change rate with respect to the flow rate (dL / d) can also be performed by the same procedure if the flow rate is measured. Further, it is possible to similarly obtain the change rate with respect to the pressure ratio or the flow rate for the power equivalent amount.

Next, as shown in FIG. 7, a method of calculating the power change rate (dL / dπ) when the corrected rotational speed changes from ▲ ▼ while the pressure ratio changes by Δπ will be described. Let R be the point at which the corrected rotational speed is ▲ ▼ and that is converted proportionally to the rotational speed under the conditions of speed triangle similarity of the blade row.
The following relationships are established between ▼ and ′ and between π ₀ and π ₀ ′, respectively.

Here, indicates the ratio of the constant pressure specific heat and the constant volume specific heat. From the formulas (6) and (7), ▲ ▼ ′ and π ₀ ′ of the point R are obtained,
If G ₀ ′ is calculated from ▲ ▼ ′ and equation (2) (dL / dπ)
Can be calculated by the following formula.

By the way, it is considered that the above-mentioned surging of the compressor does not occur simultaneously in all stages, but is directly caused by the stall of the blade row in any stage. For example, in the high-speed rotation range of the compressor, the blades on the latter stage tend to enter the surging easily. In addition, it is considered that the deterioration of blade cascade performance due to aging occurs in the upstream blade cascade where dust and the like tend to accumulate on the blade surface. Therefore, if one compressor is considered to have two or more split-stage compressors connected in series and the surging criterion described above is used for each split-stage compressor, surges with higher accuracy can be obtained. Prediction is possible.

An embodiment of the present invention will be described in detail below with reference to FIG. FIG. 1 shows an embodiment in which the compressor is used as a compressor for a single-shaft gas turbine. In this embodiment, a plurality of stationary blade rows arranged inside the casing and a rotating blade row arranged between the stationary blade rows and rotating (both not shown).
The high-pressure air flow compressed by the compressor 16 composed of and becomes high temperature and high pressure in the combustor 27, is expanded in the turbine 28, and is then discharged to the atmosphere. In this embodiment, the compressor 16, turbine 28, load 29
(For example, a generator) is arranged on one axis and rotates at the same number of revolutions. When the load 29 is a generator, the load 29 is operated at a constant rotation speed unique to the power generation cycle. In such a gas turbine, the operating point of the compressor 16 is controlled by varying the fuel flow rate entering the combustor 27. That is, if the fuel is increased and the gas temperature at the turbine inlet is increased, the volume flow rate of the high temperature gas turbine flowing into the turbine is increased, and the pressure ratio of the compressor is increased. On the other hand, if the fuel flow rate is decreased, the pressure ratio will decrease and the pressure will move away from the surge point. In the present embodiment, an opening control device for the fuel flow rate adjusting valve 30 is provided as the compressor control device 25 that changes the operating point of the compressor. A compressor inlet pressure detector 17, an inlet temperature detector 18, and a discharge pressure detector 19, a discharge temperature detector 20 are installed at the inlet of the compressor 16 and at the compressor outlet. Further, a rotation speed detector 22 that detects the rotation speed of the compressor rotor is installed at an appropriate position for detection. As the suction flow rate detecting means 21 at the compressor inlet part, for example, using the output signals from the inlet pressure detector 17, the inlet temperature detector 18, the discharge pressure detector 19, the rotation speed detector 22, a predetermined arithmetic expression Therefore, a flow rate calculator for calculating the suction flow rate is provided. Further, the output signals from the inlet pressure detector 17, the inlet temperature detector 18, the discharge pressure detector 19, the discharge temperature detector 20, the suction flow rate detecting means 21, and the rotation speed detector 22 are sent to the arithmetic unit 23. Then, the arithmetic unit 23 calculates the power change rate (dL / dπ) with respect to the pressure ratio. Further, the limit value of (dL / dπ) is stored in the storage device 24 in advance. This limit value may be a function of the correction speed, or may be a constant that does not depend on the correction speed. The compressor power change rate (dL / dπ) calculated by the arithmetic unit 23 and the storage unit 24
When (dL / dπ) reaches the limit value, the compressor controller 25 that controls the opening of the fuel adjustment valve 30 controls the inflow of the fuel flow rate into the combustor 27. Limit,
It is possible to prevent the plunge into the surging area. Further, in the present embodiment, an alarm generator 26 is provided to notify that the surge area is approaching. An alarm generator 26, such as a bell or lamp, allows the gas turbine operator to recognize that the compressor is nearing the surge limit.

In the above embodiment, the case where the surging determination is performed with the power change rate with respect to the pressure ratio (dL / dπ) has been described, but instead, the power change rate with respect to the flow rate (dL / d) may be used. Further, instead of the power change rate, the same effect can be obtained by using the following change rate of the power equivalent amount as a surging criterion.

(1) (π-1) ×… (10) (2) H _ad ×… (11) where H _ad : adiabatic head In the above embodiment (FIG. 1), the compressor controller 25 is
Although the opening control device for the fuel adjusting valve 30 is provided, instead of the bleed valve 32 provided in the bleed pipe 31 for discharging the bleed air to the outside in the compressor provided with the bleed stage as shown in FIG. It may be an opening control device. When the compressor control device is the opening control device of the bleed valve 32, for example, when the power change rate reaches a limit value, if the bleed valve 32 is opened to discharge the bleed air out of the compressor, to the surging area. Can be prevented in advance.

Further, the suction flow rate detecting means in the above embodiment (FIG. 1)
21 is a differential pressure detector (not shown) that detects the differential pressure between the total pressure at the inlet of the compressor 16 and the static pressure, and an output signal from the differential pressure detector and a predetermined correction coefficient. It may be a differential pressure type flow rate calculator for calculating the suction flow rate.

Another embodiment of the present invention will be described with reference to FIG.
FIG. 9 shows an embodiment in which the compressor 16 is used as a compressor of a single-shaft gas turbine as in the case of the above-mentioned embodiment, and the description of the components having the same drawing reference numbers as in FIG. 1 is omitted. Is omitted. In FIG. 9, at a compressor division position C such as an extraction stage located between the compressor inlet portion B and the discharge portion D, a division stage position pressure detector 33, a division stage position temperature detector 34, a division stage position. A flow rate detecting means (for example, an orifice flow meter) 35 is installed. The division stage position pressure detector 33, the division stage position temperature detector 34, the division stage position flow rate detecting means
Each output signal from 35 and the inlet pressure detector
17, each output signal from the inlet temperature detector 18, the discharge pressure detector 19, the discharge temperature detector 20, the suction flow rate detection means 21, the rotation speed detector 22 is introduced to the arithmetic unit 23, the arithmetic unit 23. The power change rates (dL / dπ) _BC and (dL / dπ) _CD for the pressure ratio π are calculated for each split-stage compressor. Also,
In the storage device 24, (dL / d
The limit value of π) is stored. This limit value may be either a function of the modified speed or a constant value. The division stage compressor power change rate (dL / dπ) _BC , (dL / dπ) _CD output from the arithmetic unit 23 is compared with the limit value stored in the storage unit 24, and (dL / dπ ) Reaches a limit value, the compressor controller 25 that controls the opening degree of the fuel adjustment valve 30 limits the inflow of the fuel flow rate into the combustor 27,
It is possible to prevent the plunge into the surging area. At this time, the power change rate of the split-stage compressor may be controlled so as to stay within each limit value for all the split-stage compressors or for at least one split-stage compressor.
By performing surging non-entry control for each split-stage compressor or for at least one split-stage compressor in this way, high-precision surge prevention control becomes possible.

In FIG. 9, the case where there is one compressor dividing position has been described, but effective surge non-entry control can be performed by providing two or more dividing stage positions. These compressor division positions may be extraction stage positions or may not be extraction stage positions. When it is not in the extraction stage position, the division position flow rate detection means 35 can be omitted.

Further, the compressor control device is provided with the bleed valve 32 shown in FIG.
The same effect can be obtained even with this opening control device.

Further, in the above embodiment, the surging determination is described with respect to the split stage compressor power change rate (dL / dπ) with respect to the pressure ratio, but instead of this, the split stage compressor power change rate with respect to the flow rate (dL / d), and ( The same effect can be obtained by adopting the rate of change of the power equivalent to the power of the split stage compressor such as π-1) ×, H _ad × with respect to the pressure ratio or the flow rate.

〔The invention's effect〕

As described above, in the present invention, unlike the conventional surging prevention device, the surging of the compressor full-stage or split-stage compressor is performed by the pressure ratio at a constant correction speed or the power change rate or the power equivalent change rate with respect to the suction flow rate. Make a decision. Therefore, even if the performance of the compressor deteriorates over time, the surge prediction can be accurately performed, which is an excellent practical effect.

[Brief description of drawings]

FIG. 1 is a system diagram showing a first embodiment of the present invention, FIG.
FIG. 3 is an explanatory view of the prior art, FIGS. 4 to 7 are tables showing compressor characteristics, FIG. 8 is an explanatory view of a compressor control device, and FIG.
The figure is a system diagram showing a second embodiment of the present invention. 16 …… Compressor, 17 …… Inlet pressure detector, 18 …… Inlet temperature detector, 19 …… Discharge pressure detector, 20 …… Discharge temperature detector, 23 …… Computing device, 24 …… Storage device, 25: Compressor control device, 33: Split stage position pressure detector, 34: Split stage position temperature detector, 35: Split stage position flow rate detection means.

Front page continuation (72) Inventor Yoshimasa Nishijima 3-1-1 Sachimachi, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Haruhiko Otsuka 3-1-1, Sachimachi, Hitachi, Ibaraki Issue: Hitachi Ltd., Hitachi Works (56) References JP-A-60-216098 (JP, A) JP-A-62-195492 (JP, A) Takefumi Ikui "Blower and Compressor (16th Edition)" ( 48-9-1) Asakura P.P. 356 ~ 358

Claims (9)

[Claims] 1. A compressor having a plurality of rows of stationary blades arranged inside a casing, and a row of rotating blades arranged between the rows of stationary blades, wherein (a) the inlet pressure of the compressor is Inlet pressure detector for detecting, (b) Inlet temperature detector for detecting inlet temperature of compressor, (c) Discharge pressure detector for detecting discharge pressure of compressor, (d) Discharge temperature of compressor A discharge temperature detector for detecting the following: (e) a flow rate detecting means for detecting a suction flow rate of the compressor; (f) a rotation speed detector for detecting a rotation speed of the compressor rotor; (g) the inlet pressure detection Output, output temperature detector, discharge temperature detector, discharge temperature detector, flow rate detector, rotation speed detector To the pressure ratio at the number of revolutions or the suction flow rate An arithmetic unit for calculating the power equivalent amount change rate, and (h) a limit value for performing surging determination by comparing the calculated value of the power change rate or the power equivalent amount change rate calculated by the arithmetic unit. (I) The calculated value exceeds the limit value and power (equivalent amount)
A control device for controlling the operating state of the compressor so that the rate of change does not become 0, and a surging prevention device for the compressor. 2. The flow rate detecting means according to claim 1, wherein the flow rate detecting means is determined in advance by using respective output signals of the inlet pressure detector, the inlet temperature detector, the discharge pressure detector, and the rotation speed detector. A surging prevention device for a compressor, which is a flow rate calculator that calculates a suction flow rate according to an arithmetic expression. 3. The differential pressure detector according to claim 1, wherein the flow rate detecting means detects a differential pressure between the total pressure at the compressor inlet and the static pressure, and detection by the differential pressure detector. A surging prevention device for a compressor, comprising: a differential pressure type flow rate calculator that calculates a suction flow rate based on a signal and a predetermined correction coefficient. 4. A surging prevention device for a compressor according to claim 1, wherein the control device comprises an alarm means for issuing an alarm when the calculated value approaches the limit value. 5. A compressor having a plurality of rows of stationary blades arranged inside a casing and a row of rotating blades arranged between the rows of stationary blades, wherein: (a) an inlet pressure of the compressor Inlet pressure detector for detecting, (b) Inlet temperature detector for detecting inlet temperature of compressor, (c) Discharge pressure detector for detecting discharge pressure of compressor, (d) Discharge temperature of compressor (E) A flow rate detecting means for detecting the suction flow rate of the compressor, (f) a rotation speed detector for detecting the rotation speed of the compressor rotor, and (j) an inlet of the compressor. Division position pressure detector that detects the pressure at the compressor division position set between the discharge section and the discharge section, (k) a division position temperature detector that detects the temperature at the compressor division position, and (l) the above Dividing position flow rate detecting means for detecting a flow rate at the compressor dividing position, and (m) the inlet pressure Output signals of detector, inlet temperature detector, discharge pressure detector, discharge temperature detector, flow rate detector, rotation speed detector, split position pressure detector, split position temperature detector, split position flow detector , For each of the plurality of split stage compressors configured with the compressor split position as a boundary, calculate the power change rate or power equivalent amount change rate of each split stage compressor with respect to at least one of each pressure ratio or suction flow rate. An arithmetic unit, and (n) for each of the split-stage compressors, a limit value for performing surging determination is compared with the calculated value of the power change rate or the power equivalent amount change rate calculated by the arithmetic unit. A storage device that stores the stored data; and (o) for at least one of the split-stage compressors, the calculated value of the compressor does not exceed the corresponding limit value and the power (equivalent amount) change rate becomes 0. Surging prevention device of a compressor, characterized in that a control device for controlling the dynamic state. 6. The flow rate detecting means according to claim 5, wherein the flow rate detecting means is predetermined by using output signals of the inlet pressure detector, the inlet temperature detector, the discharge pressure detector, and the rotation speed detector. A surging prevention device for a compressor, which is a flow rate calculator that calculates a suction flow rate according to an arithmetic expression. 7. The differential pressure detector according to claim 5, wherein the flow rate detecting means detects a differential pressure between the total pressure at the compressor inlet and the static pressure, and the differential pressure detector. A surging prevention device for a compressor, comprising: a differential pressure type flow rate calculator that calculates a suction flow rate based on a signal and a predetermined correction coefficient. 8. The surging prevention device for a compressor according to claim 5, wherein the control device includes alarm means for issuing an alarm when the calculated value approaches the corresponding limit value. . 9. The surging prevention device for a compressor according to claim 5, wherein the compressor division position is an extraction position of the compressor.