KR20100037122A

KR20100037122A - Gas compression device and method of controlling gas compression device

Info

Publication number: KR20100037122A
Application number: KR1020107001953A
Authority: KR
Inventors: 유지 고마츠; 류고 가나야; 가즈미츠 하세가와
Original assignee: 가부시키가이샤 아이에이치아이
Priority date: 2007-07-19
Filing date: 2008-07-07
Publication date: 2010-04-08
Also published as: CN101755127A; EP2180192A1; WO2009011241A1; JP2009024582A

Abstract

A gas compression device for compressing gas by multiple compression means arranged in series relative to the direction of flow of the gas. The flow rate of the gas sucked into a gas compression section is controlled according to the amount of demand of the gas from a user. When the flow rate of each compression means is less than a set value set based on a surge limit, at least a part of gas discharged from the gas compression section is circulated and supplied to a diffuser of the compression means. In the construction above, a load on drive means is sufficiently reduced while occurrence of surge in the compression means is suppressed and, as a result, the amount of energy consumption is reduced.

Description

Gas compression device and method of controlling gas compression device

The present invention relates to a gas compression device having a plurality of compression means driven by a single drive means and a control method of the gas compression device.

This application claims priority based on Japanese Patent Application No. 2007-188093 for which it applied to Japan on July 19, 2007, and uses the content here.

Background Art Conventionally, a turbo compression device (gas compression device) having a plurality of centrifugal compressors (compression means) connected to a shaft that is rotationally driven by a single motor (drive means) has been used.

In such a turbo compression device, each centrifugal compressor is arranged in series with respect to the flow direction of the gas, and the gas is gradually compressed in each centrifugal compressor.

By the way, in the general factory, in the apparatus (demand) to which the gas compressed from a turbo compression apparatus (henceforth a compressed gas) is supplied, the quantity (demand quantity) of the required compressed gas changes with time. In other words, the amount of compressed gas supplied from the turbo compression device to the device on demand changes with time.

In order to reduce the amount of compressed gas demand, the amount of compressed gas is reduced by reducing the amount of intake of gas into the turbo compressor, or a certain amount of gas is always compressed and supplied to the device of the demand as needed and exhausted. It is conceivable to cope with the method, but it is preferable to cope with the method of reducing the amount of compressed gas, which can reduce the energy consumption in the turbo compression device (ie, reduce the load on the motor).

In order to reduce the amount of compressed gas, it is necessary to reduce the flow rate of the gas flowing in the turbo compression device. In centrifugal compressors, however, surging occurs when the flow rate of the flowing gas is reduced above a certain limit. More specifically, when the gas accelerated by the impeller of the centrifugal compressor is decelerated in the diffuser, the flow of this gas becomes slow and this becomes a factor of surging occurrence.

Therefore, in the conventional turbo compression apparatus, by using the method of avoiding surging in the centrifugal compressors disclosed in Patent Documents 1 to 4, for example, the load on the motor is reduced while suppressing surging in the centrifugal compressor.

Patent Document 1: Japanese Patent Application Laid-Open No. 2-61640 Patent Document 2: Japanese Patent Application Laid-Open No. 2-59317 Patent Document 3: Japanese Patent Application Laid-Open No. 59-99196 Patent Document 4: Japanese Patent Application Laid-Open No. 10-252696

However, in the conventional centrifugal compressor, even if the technique disclosed in Patent Literatures 1 to 4 is used, it is difficult to sufficiently suppress surging in an environment where the flow rate of the gas sucked into the centrifugal compressor is small, so that the flow rate of the gas drawn into the centrifugal compressor is 60 to 70% or less. Could not be reduced. Therefore, the load on the motor could not be reduced to 60 to 70% or less.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and in the gas compression device for compressing gas by a plurality of compression means arranged in series with respect to the flow direction of the gas, the driving means is suppressed while suppressing the occurrence of surging in the compression means. The aim is to reduce the consumption of energy by sufficiently reducing the load.

In order to achieve the above object, a gas compression device, which is a first embodiment of the present invention, includes a compression means including an impeller for imparting velocity energy to a gas, and a diffuser for converting the velocity energy into pressure energy in a gas flow direction. A gas compression device arranged in series with each other in series and supplying a gas compressed through a plurality of said compression means to a predetermined demand destination, comprising: drive means for supplying power to the impeller; Flow rate adjusting means for adjusting the flow rate of the gas sucked into the compression means, and at least a portion of the gas discharged from the compression means located downstream from the flow direction of the gas between the diffuser or the diffuser of each compression means and the impeller; Circulation supply means capable of circulation supply, and at least the drive means and the flow rate adjustment number And control means for controlling the circulation supply means, wherein the control means controls the flow rate adjusting means according to the demand amount of the gas at the demand destination, and in each compression means, the flow rate of the gas to be sucked is compressed. When below the set value set based on the surging limit in the means, the circulation supply means is controlled to circulate a part of the gas to the compression means.

According to this gas compression device, the flow rate adjusting means is controlled in accordance with the gas demand amount of the demand destination. In other words, when the gas demand amount of the demand destination is reduced, the flow rate of the gas sucked into the gas compression device is reduced according to this decrease amount.

And in each of the compression means, when the flow rate of the gas to be sucked is lower than a set value set based on the surging limit in the compression means, a part of the gas in the compression means and the diffuser or the diffuser of each compression means. The circulation is supplied between the impeller.

In addition, the gas compression device includes pressure detection means for detecting the pressure of the gas discharged from the downstream compression means, and flow rate detection means for detecting the flow rate of the gas discharged from the compression means located downstream. The means may control the flow rate adjusting means by using at least a detection result of the pressure detecting means among the pressure detecting means and the flow rate detecting means as a demand amount of the gas at the demand destination.

The control means may start circulating supply of the gas by the circulation supply means stepwise toward the upstream compression means from the compression means located downstream.

The set value may be a value obtained by adding the flow rate of the surging limit in the compression means and a predetermined margin.

The control means, when the demand amount of the gas at the demand destination is zero, maintains the suction of the gas from the compression means located most upstream with respect to the flow direction of the gas, and at the most downstream of the flow direction of the gas. A part of the gas discharged from the located compression means may be exhausted without being supplied to the demand destination.

Next, the control method of the gas compression apparatus which is 2nd Embodiment of this invention provides the compression means provided with the impeller which gives rate energy to gas, and the diffuser which converts this speed energy into pressure energy with respect to the flow direction of gas. A control method of a gas compression apparatus arranged in series in plural and supplying compressed gas through a plurality of said compression means to a predetermined demand destination, said control method being located upstream with respect to the flow direction of said gas in accordance with the demand amount of said gas at said demand destination. The flow rate of the gas sucked into the compression means is adjusted, and in each compression means, when the flow rate of the gas to be sucked falls below the set value set based on the surging limit in the compression means, At least a portion of the gas discharged from the compression means located downstream of the Or a circulation supply between the diffuser and the impeller.

According to the control method of this gas compression apparatus, the flow volume of the gas sucked into a gas compression apparatus is controlled according to the gas demand amount of a demand destination. In other words, when the gas demand amount at the demand destination is reduced, the flow rate of the gas sucked into the gas compression device is reduced according to this decrease amount.

And in each of the compression means, when the flow rate of the gas to be sucked is lower than the set value set based on the surging limit in the compression means, a part of the gas discharged from the compression means located downstream from the compression means A circulation is supplied between the diffuser of the compression means or between the diffuser and the impeller.

Even if the pressure and the flow rate of the gas discharged from the compression means located at the downstream side are detected, the flow rate of the gas sucked into the compression means located at the most upstream can be controlled by making at least the pressure the demand amount of the gas at the demand destination among the detection results. do.

It is also possible to start circulating supply of the gas stepwise from the downstreammost compression means toward the upstream compression means.

When the demand amount of the gas at the demand destination is zero, the suction of the gas in the compression means located most upstream with respect to the flow direction of the gas is maintained, and discharged from the compression means located downstream with respect to the flow direction of the gas. A part of the used gas may be exhausted without being supplied to the demand destination.

According to the gas compression apparatus and the control method of the gas compression apparatus of this invention, the flow volume of the gas sucked into a gas compression apparatus is controlled according to the gas demand amount of a destination. In other words, when the gas demand amount at the demand destination is reduced, the flow rate of the gas sucked into the gas compression device is reduced according to this decrease amount.

Here, the circulated supply gas flows into the diffuser without being supplied to the impeller. Therefore, a gas of sufficient flow rate can be supplied to the diffuser without increasing the load on the impeller, and generation of stall and generation of surging can be suppressed without increasing the load on the driving means. That is, even if the flow rate of the gas sucked into each compression means is small, the gas of the flow rate which can suppress surging can flow into the diffuser of a compression means.

Therefore, according to the present invention, in a gas compression device for compressing gas by a plurality of compression means arranged in series with respect to the flow direction of the gas, energy is reduced by sufficiently reducing the load of the driving means while suppressing occurrence of surging in the compression means. The consumption can be reduced.

1 is a block diagram showing a schematic configuration of a turbo compression device according to one embodiment of the present invention.
2 is a cross-sectional view of a centrifugal compressor with a turbo compression device according to one embodiment of the present invention.
3 is a table showing a flow rate distribution of gas in a turbo compression device according to one embodiment of the present invention.
4 is a graph showing a load change of a motor included in a turbo compression device according to an embodiment of the present invention.
It is a schematic diagram which shows the modification of the turbo compression apparatus which is one Embodiment of this invention.
It is a schematic diagram which shows the modification of the turbo compression apparatus which is one Embodiment of this invention.
It is a schematic diagram which shows the modification of the turbo compression apparatus which is one Embodiment of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of the gas compression apparatus and the control method of a gas compression apparatus which concern on this invention with reference to drawings is demonstrated. In the following drawings, the scale of each member is appropriately changed in order to make each member a size that can be recognized.

1 is a block diagram showing a schematic configuration of a turbo compression device S (gas compression device) of the present embodiment.

As shown in this figure, the turbo compression device S of the present embodiment includes an inlet guide vane 1 (flow rate adjusting means), a gas compression unit 2, and a first circulation supply control valve 3 (circulation supply means). ), Second circulation supply control valve 4 (circulation supply means), exhaust control valve 5, flow rate detector 6 (flow rate detection means), pressure detector 7 (pressure detection means), and control device 8 (Control means).

The inlet guide vane 1 is for adjusting the flow rate of the gas sucked into the gas compression unit 2 and is controlled by the control device 8. As will be described later, the gas compressor 2 has a configuration in which two (plural) centrifugal compressors 21 and 22 (compression means) are arranged in series in the gas flow direction. The gas sucked into the gas compression section 2 through the inlet guide vanes 1 is first sucked into the centrifugal compressor 21 located upstream (upstream) with respect to the flow direction of the gas. That is, the inlet guide vane 1 adjusts the flow rate of the gas sucked into the centrifugal compressor 21 located at the most upstream with respect to the flow direction of the gas.

This inlet guide vane 1 changes the direction of gas in the same direction as the rotational direction of the impeller 21a (see FIG. 2) included in the centrifugal compressor 21. Thereby, the work amount of the impeller of the centrifugal compressor 21 is reduced.

As a substitute for the inlet guide vane 1, a butterfly valve can also be used. In this case, the flow rate of the gas to be sucked is adjusted by giving resistance to the gas without changing the direction of the gas.

The gas compression unit 2 includes two centrifugal compressors 21 and 22 (compression means) arranged in the gas flow direction, and impellers 21a and 22a provided in the centrifugal compressors 21 and 22. Cooling the gas discharged from the motor 23 (drive means) for supplying rotational power to the power) and the centrifugal compressor 21 (hereinafter referred to as the first centrifugal compressor 21) located upstream with respect to the flow direction of the gas. And an after cooler 25 for cooling the gas discharged from the centrifugal compressor 22 (hereinafter referred to as the second centrifugal compressor 22) located downstream from the gas flow direction. have.

The first centrifugal compressor 21 and the second centrifugal compressor 22 compress and discharge the gas to be sucked. FIG. 2: is sectional drawing for demonstrating schematic structure of the 1st centrifugal compressor 21 and the 2nd centrifugal compressor 22. As shown in FIG. Since the first centrifugal compressor 21 and the second centrifugal compressor 22 have the same configuration, a single centrifugal compressor is shown in FIG. In addition, in FIG. 2, the code | symbol outside a parenthesis corresponds to the 1st centrifugal compressor 21, and the code | symbol in parentheses corresponds to the 2nd centrifugal compressor 22. In addition, in FIG.

As shown in Fig. 2, the centrifugal compressor 21 (22) has a casing body 21c (22c) having a scroll flow passage 21b (22b) that is open at one side and extends in the circumferential direction near the inner periphery. ), And the gas discharge pipe 21d (22d) provided in the predetermined part of the casing main body 21c (22c) so that it may be connected to the scroll flow path 21b (22b), and the casing main body 21c (22c). The rotor shaft 21f (22f) which rotatably penetrates the sealing member 21e (22e) provided in the center of the side wall part, and is located in the inner center of the casing main body 21c (22c), and also the rotor shaft 21f (22f). ) And the opening of the casing main body 21c (22c) so as to cover the impeller 21a (22a) and the outside of the impeller 21a (22a). An annular casing cover 21i (22i) that forms a diffuser 21h (22h) that extends from the periphery of the gas inlet 21g (22g) and the impeller 21a (22a) toward the front end to the scroll flow passage 21b (22b). )) And diffuser ( 21h (22h) is provided with many diffuser vanes 21j (22j) arranged at equal intervals in the circumferential direction.

And the rotor shaft 21f of the 1st centrifugal compressor 21 and the rotor shaft 22f of the 2nd centrifugal compressor 22 are respectively connected with the motor 23 via a gear speed increase mechanism. And the impeller 21a (22a) rotates at the rotational speed according to the output of the motor 23. As shown in FIG.

The diffuser vane 21j (22j) is an annular vane support base 211 (221) provided in the recess 21k (22k) provided to surround the impeller 21a (22a) inside the casing body 21c (22c). It is integrally formed with respect to.

Moreover, the cross-sectional shape of the flow path of the scroll flow path 21b (22b) is formed so that it becomes larger as it comes closer to the gas discharge pipe 21d (22d).

In the centrifugal compressor 21 (22), the casing cover (21i (22i)) is provided with a plurality of bypass flow path holes (21m (22m)) located between the impeller (21a) (22a) and the diffuser vanes (21j (22j)). It is. This bypass flow path hole 21m (22m) is for flowing gas from the outside of the centrifugal compressor 21 (22) toward the front edge of the diffuser vane 21j (22j) of the diffuser 21h (22h). Euro. The plurality of bypass flow path holes 21m (22m) are formed in the rotational direction of the impeller 21a (22a). That is, the diffuser 21h (22h) and the exterior are connected by the some bypass flow path 21m (22m).

In such a centrifugal compressor 21 (22), velocity energy is provided by the impeller 21a (22a) rotationally driven with respect to the gas which flowed in from the gas inflow port 21g (22g). The velocity energy applied to the gas is converted into pressure energy by the diffuser vanes 21j (22j). As a result, the gas is compressed, and the compressed gas is discharged to the outside of the centrifugal compressor 21 22 through the scroll flow passage 21b (22b). The gas flowing through the bypass flow passage hole 21m (22m) is not supplied to the impeller 21a (22a) but is diffuser vane 21j (with the gas imparted with velocity energy by the impeller 21a (22a). 22j).

In FIG. 1, the diffuser vanes 21j (22j) and the scroll flow passages 21b (22b) are shown only on one side of the impeller 21a (22a) for convenience, but are actually present over the entire circumference. The bypass flow path holes 21m (22m) are formed at equal intervals between the impeller 21a (22a) and the diffuser vanes 21j (22j) that exist across the entire circumference, and each bypass flow path hole 21m ( 22 m)), the gas is supplied evenly.

Returning to FIG. 1, the motor 23 is connected with the impeller 21a and the impeller 22a, and the impeller 21a and the impeller 22a are driven to rotate at fixed speed. As such a motor 23, an induction motor can be used, for example.

The first circulation supply control valve 3 passes part or all of the gas discharged from the gas compression unit 2 into the bypass flow path hole 21m (ie, the impeller 21a and the diffuser vane) of the first centrifugal compressor 21. It is for making it possible to supply circular circulation between (21j).

The opening degree of this 1st circulation supply control valve 3 is controllable by the control apparatus 8. As shown in FIG. The flow rate of the gas supplied to the bypass flow path hole 21m is adjusted by adjusting the opening degree of the first circulation supply control valve 3.

The second circulation supply control valve 4 passes a part or all of the gas discharged from the gas compression unit 2 into the bypass flow path hole 22m of the second centrifugal compressor 22 (that is, the impeller 22a and the diffuser vane). It is for making it possible to circulate-feed between (22j).

The opening degree can be controlled by the control apparatus 8 of this 2nd circulation supply control valve 4. And the flow volume of the gas supplied to the bypass flow path hole 22m is adjusted by adjusting the opening degree of the 2nd circulation supply control valve 4.

The exhaust control valve 5 is for exhausting a part or all of the gas discharged from the gas compression unit 2 to the outside of the turbo compression device S, and can be controlled by the control device 8 to open and close.

The flow rate detector 6 measures a flow rate of the gas discharged from the gas compression unit 2 and a flow rate of the gas discharged from the gas compression unit 2 (that is, the second centrifugal compressor). And a transmitter that outputs as a signal indicating the flow rate of the gas discharged from the gas (22).

The pressure detector 7 measures the pressure of the gas discharged from the gas compression unit 2 (that is, the pressure of the gas discharged from the second centrifugal compressor 22), and the measurement result of the measurement device is a gas compression. It has a transmitter which outputs as a signal which shows the pressure of the gas discharged | emitted from the part 2.

The control device 8 includes an inlet guide vane 1 (or butterfly valve), a motor 23 of the gas compression unit 2, a first circulation supply control valve 3, and a second circulation supply control valve 4. And the exhaust control valve 5, the flow rate detector 6, and the pressure detector 7 are electrically connected.

In the turbo compression device S of this embodiment as described above, the gas sucked from the outside through the filter f or the like is compressed by the gas compression unit 2 and discharged. The gas supplied from the gas compression unit 2 to the first centrifugal compressor 21 through the first circulation supply control valve 3 and the second centrifugal flow through the second circulation supply control valve 4 are used. Gases other than the gas supplied to the compressor 22 and the gas exhausted to the outside through the exhaust control valve 5 are supplied to the apparatus at the demand destination.

And the control apparatus 8 compares the detection result of the pressure detector 7 with a predetermined setting value, and controls the inlet guide vane 1 first.

In more detail, when the pressure of the gas behind the gas compression unit 2 is a predetermined desired pressure set value, the flow rate of the gas supplied from the turbo compression device S to the device of the demand destination and the device of the demand destination are required. It shows that the flow rates of the gas to be the same. When the flow rate of the gas required by the device at the demand destination is changed, the balance between the flow rate of the gas supplied from the turbo compression device S to the device at the destination and the flow rate of the gas required by the device at the destination is broken and the gas is compressed. The pressure of the gas discharged from the section 2 is changed.

Therefore, the control apparatus 8 compares the detection result of the pressure detector 7 with a predetermined setting value, and controls the inlet guide vane 1 so that it may become the above-mentioned desired pressure. As a result, the flow rate of the gas supplied from the turbo compression device S to the apparatus at the demand destination can be matched with the flow rate of the gas required at the apparatus at the destination destination.

In this way, the pressure of the gas behind the gas compression unit 2 (the pressure of the gas discharged from the downstreammost compression means) is related to the flow rate of the gas supplied from the turbo compression device S to the device of the demand destination. That is, controlling the inlet guide vanes 1 based on the detection result of the pressure detector 7 means that the inlet guide vanes 1 are controlled based on the flow rate of the gas supplied from the turbo compression device S to the device at the demand destination. To control.

Subsequently, when the detection result of the pressure detector 7 reaches a desired pressure, the control apparatus 8 confirms the flow volume of the gas discharged from the gas compression part 2 from the detection result of the flow rate detector 6. . In addition to the detection result of the pressure detector 7, the inlet guide vane 1 may be controlled using the detection result of the flow rate detector 6 as well.

In the case where fast control of the inlet guide vanes 1 is not required, the flow rate of the gas supplied to the apparatus at the demand destination can be measured directly and the measurement result can be replaced with the detection result of the pressure detector 7.

And the control apparatus 8 has surging in the centrifugal compressors 21 and 22 which the flow volume of the gas sucked into each centrifugal compressors 21 and 22 as a result of the control of the inlet guide vane 1 previously memorizes. When below the set value set based on the limit, by controlling the first circulation supply control valve 3 and / or the second circulation supply control valve 4, the first centrifugal compressor 21 and / or the second A part of the gas discharged from the gas compression unit 2 is circulated and supplied to the centrifugal compressor 22.

The control apparatus 8 firstly performs the second circulation when the flow rate of the gas sucked through the first centrifugal compressor 21 in the second centrifugal compressor 22 falls below the set value set based on the surging limit. A part of the gas discharged from the gas compression section 2 by controlling the supply control valve 4 is transferred between the impeller 22a and the diffuser vane 22j of the second centrifugal compressor 22 (that is, the diffuser 21h (22h)). It is supplied circulating to). And the control apparatus 8 further supplies a 1st circulation supply when the flow rate of the gas sucked in through the inlet guide vane 1 in the 1st centrifugal compressor 21 falls below the setting value set based on the surging limit. A part of the gas discharged from the gas compression section 2 by controlling the control valve 3 is transferred between the impeller 21a and the diffuser vane 21j of the first centrifugal compressor 21 (that is, the diffuser 21h (22h)). Circulate).

In the turbo compression device S of the present embodiment, the set value set based on the surging limit is a value obtained by adding the flow rate of the surging limit and a predetermined margin. In addition, the flow rate of a surging limit shows the flow volume of the gas of the minimum limit which surging does not generate | occur | produce in each centrifugal compressor (S).

The flow rate of the gas sucked into the first centrifugal compressor 21 corresponds to the opening degree of the inlet guide vane 1. The flow rate of the gas sucked into the second centrifugal compressor 22 depends on the opening degree of the inlet guide vane 1 and the opening degree of the first circulation supply control valve 3. And the opening degree of the 1st circulation supply control valve 3 is controlled based on the opening degree of the inlet guide vane 1. Therefore, the flow rate of the gas sucked into the centrifugal compressors 21 and 22 is uniquely determined according to the opening degree of the inlet guide vane 1.

When the gas demand amount of the demand destination device is zero, the control device 8 opens the exhaust control valve 5 while maintaining the suction of the gas in the gas compression unit 2 through the inlet guide vanes 1 to release the gas. Exhaust to the outside.

That is, the control device 8 does not completely close the inlet guide vanes 1 even when the gas demand amount of the demand destination device is zero, and maintains the operation of the turbo compression device S with a minimum energy consumption.

In the turbo compression device S of the present embodiment configured as described above, the gas sucked from the outside is sucked into the turbo compression device S through the inlet guide vanes 1 and sucked into the gas compression unit 2. In the gas compression unit 2, the gas is compressed by the first centrifugal compressor 21 and then cooled by the inter cooler 24, and after being compressed by the second centrifugal compressor 22 by the after cooler 25. Cooled and discharged.

The gas discharged from the gas compression unit 2 is distributed according to the opening degree of the first circulation supply control valve 3, the second circulation supply control valve 4, and the exhaust control valve 5, and the rest is supplied to the device of the demand destination. do.

And the gas distributed by the 1st circulation supply control valve 3 is supplied between the impeller 21a and the diffuser vane 21j of the 1st centrifugal compressor 21 as needed. The gas distributed by the second circulation supply control valve 4 is supplied between the impeller 22a and the diffuser vane 22j of the second centrifugal compressor 22. In addition, the gas distributed by the exhaust control valve 5 is exhausted to the outside.

Next, a specific operation (control method) of the turbo compression device S of the present embodiment configured as described above will be described with reference to FIGS. 3 and 4. In the following description, (flow rate%) represents the weight flow rate% of gas, and let flow volume in each place at the time of making the opening degree of the inlet guide vane 1 maximum 100 flow%.

3 is a table which shows (flow rate%) in each position A-I corresponding to (flow rate%) of the gas supplied to the apparatus of a demand destination. 4 is a graph showing the relationship between the demand flow rate and the motor load to the apparatus at the demand destination. As shown in FIG. 1, A in FIG. 3 is an upstream position of the inlet guide vane 1, B is a position between the inlet guide vane 1 and the first centrifugal compressor 21, and C is a first centrifugal compressor. The exhaust control valve 5 as a position between 21 and the second centrifugal compressor 22, D as a downstream position of the second centrifugal compressor 22, and E as a downstream position of the second centrifugal compressor 22; Is the position after the gas exhausted through has been removed, and F is the position downstream of the second centrifugal compressor 22, separated from the first circulation supply control valve 3 and the second circulation supply control valve 4; , G is the downstream position of the exhaust control valve, H is the position between the first circulation supply control valve 3 and the first centrifugal compressor 21, I is the second circulation supply control valve 4 and the second centrifugal. It is a position between the compressors 22, and J is a position immediately before the demand destination.

In the present embodiment, the set value based on the surging limit of the first centrifugal compressor 21 is 60 flow%, and the set value based on the surging limit of the second centrifugal compressor 22 is 70 flow%.

First, when the demand flow rate of the demand destination device is 100% flow rate (that is, when the flow rate in J is 100 flow%), the opening degree of the inlet guide vane 1 becomes the maximum, whereby the flow rate in A to D is 100. The flow rate is%. When the demand flow rate of the demand destination device is 100 flow%, the control device 8 sets the output of the motor 23 to 100%, and the first circulation supply control valve 3 and the second circulation supply control valve. (4) and the exhaust control valve 5 are controlled in a closed state. As a result, the flow rate in E becomes 100 flow rate%, and the flow rates in F to I become 0 flow rate%. That is, when the demand flow rate of the demand destination apparatus is 100 flow rate%, all the gas is supplied to the apparatus of the demand destination, and it is not circulated supplied to the 1st centrifugal compressor 21 and the 2nd centrifugal compressor 22.

When the demand flow rate of the demand destination device is 100 flow rate%, the flow rate of the gas sucked into the first centrifugal compressor 21 and the flow rate of the gas supplied to the second centrifugal compressor 22 become 100 flow rate%, so that the motor The load at 23 is also 100% as shown in FIG.

When the demand flow rate of the demand destination device is 70 flow% (that is, when the flow rate at J is 70 flow%), the control device 8 narrows the opening degree of the inlet guide vane 1 and changes the flow rate at A to 70 flow rates. %. In this case, the flow volume in B-D also becomes 70 flow volume%. When the demand flow rate of the demand destination device is 70 flow%, the control device 8 closes the first circulation supply control valve 3, the second circulation supply control valve 4, and the exhaust control valve 5. To control. As a result, the flow volume in E becomes 70 flow%, and the flow rates in F to I become 0 flow%. That is, when the demand flow rate of the demand destination apparatus is 70 flow rate%, all the gas is supplied to the demand destination apparatus and it is not circulated supplied to the 1st centrifugal compressor 21 and the 2nd centrifugal compressor 22.

When the demand flow rate of the demand destination device is 70 flow rate%, the flow rate of the gas sucked into the first centrifugal compressor 21 and the flow rate of the gas sucked into the second centrifugal compressor 22 become 70 flow rate%, so that the motor The load of (23) is also about 70% as shown in FIG.

When the demand flow rate of the demand destination device is 60 flow% (that is, when the flow rate in J is 60 flow%), the control apparatus 8 narrows the opening degree of the inlet guide vane 1, and changes the flow volume in A to 60 flow rates. %. In this case, when the second circulation supply control valve 4 is closed, the flow rate of the gas sucked into the second centrifugal compressor 22 falls below 70 flow rate%, which is a set value, so that the control device 8 compresses the gas. The second circulation supply control valve 4 is opened to circulate and supply the second centrifugal compressor 22 by 10 flow rate% of the gas discharged from the section 2. The first circulation supply control valve 3 and the exhaust control valve 5 remain closed. As a result, the flow rates at B and C are 60 flow%, the flow rates at D and E are 70 flow%, the flow rates at F and I are 10 flow%, and the flow rates at G and H are 0 flow%.

In the second centrifugal compressor 22, since the flow rate in the diffuser 22h is 70 flow%, generation of surging in the second centrifugal compressor 22 can be suppressed.

On the other hand, since the flow rate in the impeller 22a and the flow rate of the impeller 21a of the 1st centrifugal compressor 21 are 60 flow%, the load of the motor 23 can be reduced to about 60% as shown in FIG.

If the demand flow rate of the destination device is 50 flow% (that is, the flow rate at J is 50 flow%), the control device 8 narrows the opening degree of the inlet guide vane 1 to reduce the flow rate at A to 50 flow%. Shall be. In this case, when the 1st circulation supply control valve 3 and the 2nd circulation supply control valve 4 remain closed, the flow volume of the gas suctioned in the 1st centrifugal compressor 21 and the 2nd centrifugal compressor 22 will respectively be. Since it is less than 60 flow% and 70 flow% which are the setting values of the control unit 8, 10 flow% of the gas discharged | emitted from the gas compression part 2 is 10 flow% by the 1st centrifugal compressor 21 by 10 flow%. The first circulation supply control valve 3 and the second circulation supply control valve 4 are opened to circulate the second centrifugal compressor 22. The exhaust control valve 5 remains closed. As a result, the flow rate at B is 50 flow%, the flow rate at C is 60 flow%, the flow rate at D and E is 70 flow%, the flow rate at F is 20 flow%, the flow rate at G is 0 flow%, The flow rates in H and I are 10 flow%.

In the first centrifugal compressor 21, the flow rate in the diffuser 21h becomes 60 flow%, and in the second centrifugal compressor 22, the flow rate in the diffuser 22h becomes 70 flow%, so the first centrifugal compressor Generation of surging in the 21 and the second centrifugal compressor 22 can be suppressed.

On the other hand, since the flow rate in the impeller 21a becomes 50 flow% and the flow rate in the impeller 22a becomes 60 flow%, the load on the motor 23 is the demand flow rate of the demand destination device as shown in FIG. In the case of 60 flow%, it is further reduced.

When the demand flow rate of the demand destination device is 10 flow% (that is, when the flow rate in J is 10 flow%), the control device 8 narrows the opening degree of the inlet guide vane 1 and changes the flow rate in A to 10 flow rates. %. In this case, if the 1st circulation supply control valve 3 and the 2nd circulation supply control valve 4 remain closed, the flow volume of the gas suctioned by the 1st centrifugal compressor 21 and the 2nd centrifugal compressor 22 will be Since the flow rate is lower than the respective set values of 60% and 70% by volume, the control device 8 has 50% by volume of the gas discharged from the gas compression section 2 to the first centrifugal compressor 21, and 10% by volume. The first circulation supply control valve 3 and the second circulation supply control valve 4 are opened so as to be circulated and supplied to the second centrifugal compressor 22. The exhaust control valve 5 remains closed. As a result, the flow rate at B is 10 flow%, the flow rate at C is 60 flow%, the flow rate at D and E is 70 flow%, the flow rate at F is 60 flow%, the flow rate at G is 0 flow%, The flow rate in H is 50 flow% and the flow rate in I is 10 flow%.

On the other hand, since the flow rate in the impeller 21a becomes 10 flow rate% and the flow rate in the impeller 22a becomes 60 flow rate%, the load on the motor 23 is demanded of the demand destination apparatus as shown in FIG. It is further reduced compared to the case where the flow rate is 50 flow%.

When the demand flow rate of the demand destination device is O flow rate% (that is, when the flow rate in J is O flow rate%), the control device 8 is similar to the case where the demand flow rate of the demand destination device is 10 flow%. The first circulation supply control valve 3 and the second circulation supply so that 50 flow% of the gas discharged from 2) is circulated to the first centrifugal compressor 21 by 10 flow% by the flow rate. Open the control valve (4). Then, it is opened through the exhaust control valve 5 to maintain the output of the motor 23 at 10%. As a result, the flow rate at B is 10 flow%, the flow rate at C and E is 60 flow%, the flow rate at D is 70 flow%, the flow rate at F is 60 flow%, the flow rate at G is 10 flow%, The flow rate in H is 50 flow% and the flow rate in I is 10 flow%.

As described above, in the turbo compression device S of the present embodiment, the circulating supply of the gas is started step by step toward the first centrifugal compressor 21 upstream from the second centrifugal compressor 22 located at the downstream.

According to the control method of the turbo compression apparatus and the turbo compression apparatus of this embodiment as described above, the flow rate of the gas which the turbo compression apparatus S inhales is controlled in proportion to the demand flow volume (demand quantity) of the gas of a demand destination apparatus. That is, when the demand flow rate of the gas of the demand destination device decreases, the flow rate of the gas which the turbo compression device S inhales decreases corresponding to this decrease amount.

In the centrifugal compressors 21 and 22, when the flow rate of the gas to be sucked falls below a set value set based on the surging limit in the centrifugal compressors 21 and 22, the centrifugal compressor ( A part of the gas discharged from the gas compression unit 2 to the 21 and 22 is circulated and supplied to the diffusers 21h and 22h of the centrifugal compressors 21 and 22 so that surging is suppressed.

The gas circulated and supplied here flows into the diffusers 21h and 22h without being supplied to the impellers 21a and 22a. Therefore, gas of sufficient flow rate can be supplied to the diffusers 21h and 22h without increasing the load on the impellers 21a and 22a and generation of surging can be suppressed without increasing the load to the motor. That is, even when the flow rate of the gas sucked into the first centrifugal compressor 21 is somewhat small, the flow rate that can suppress surging in the diffusers 21h and 22h of the centrifugal compressors 21 and 22, respectively. Gas can flow in.

Therefore, according to this embodiment, in the turbo compression apparatus which compresses gas by the centrifugal compressors 21 and 22 arranged in series with respect to the flow direction of gas, the surging in the centrifugal compressors 21 and 22 is carried out. The amount of energy consumed can be reduced by sufficiently reducing the load of the motor while suppressing the occurrence of?

In addition, according to the control method of the turbo compression device and the turbo compression device of the present embodiment, when the demand flow rate of the gas of the demand destination device is zero, the gas compression unit 2 maintains suction of the gas from the gas compression unit 2. A part of the gas discharged from 2) (the gas which is not circulated and supplied in the gas discharged from the gas compression section 2) is exhausted without being supplied to the apparatus at the demand destination. Therefore, even when the gas demand amount of the demand destination device is zero, the operation of the turbo compression device S can be maintained at the minimum energy consumption without completely closing the inlet guide vanes 1. Therefore, when it is necessary to supply gas to the apparatus of a demand destination again, supply can be resumed promptly.

Moreover, according to the control method of the turbo compression apparatus and the turbo compression apparatus of this embodiment, the set value regarding the 1st centrifugal compressor 21 and the 2nd centrifugal compressor 22 previously memorize | stored in the control apparatus 8 is centrifugal compressor. It was set as the sum of the flow rate of the surging limit in (21) and (22), and predetermined margin. Therefore, since the gas is circulated and supplied to each of the centrifugal compressors 21 and 22 with a margin for the flow rate of the surging limit, it is possible to reliably suppress the occurrence of surging.

In general, in the gas compression section 2, since the flow rate coefficient of the centrifugal compressor located downstream in the gas flow direction is small, first, the gas is circulated and supplied to the centrifugal compressor located downstream. However, for example, by setting the margin at the set value for the first centrifugal compressor 21 to be larger than the margin at the set value for the second centrifugal compressor 22, the respective centrifugal compressors 21 and 22 are set. It is possible to simultaneously start the circulating supply of gas to the gas, thereby simplifying the control.

As mentioned above, although preferred embodiment of the gas compression apparatus and the control method of the gas compression apparatus which concern on this invention was described with reference to drawings, it cannot be overemphasized that this invention is not limited to the said embodiment. All shapes, combinations, and the like of the respective constituent members shown in the above-described embodiments are examples and can be variously changed based on design requirements and the like without departing from the spirit of the present invention.

For example, in the said embodiment, the case where two centrifugal compressors with which a turbo compression apparatus was equipped was demonstrated.

However, the present invention is not limited to this, and may be the case of three or more centrifugal compressors. In such a case, for example, by appropriately setting the margin at the set value for each centrifugal compressor, a configuration may be employed in which the gas is circulated and supplied to several centrifugal compressors at the same time.

In the case where three centrifugal compressors are provided, specifically, as shown in the schematic diagram of FIG. 5, the downstream centrifugal compressor X3, the midstream centrifugal compressor X2, and the most upstream centrifugal compressor X1 are stepwise. Circulating supply of gas may be started, and as shown in the schematic diagram of FIG. 6, circulation supply is started simultaneously with the most downstream centrifugal compressor X3 and the middle flow centrifugal compressor X2, and is then sent to the most upstream centrifugal compressor X1. The circulating supply may be started, and as shown in the schematic diagram of FIG. 7, after the circulating supply is started for the downstream centrifugal compressor X3, the middle flow centrifugal compressor X2 and the most upstream centrifugal compressor X1 are started. The circulation supply may be started at the same time.

Since the final downstream compression stage has a small flow coefficient and thus enters the surge first, in any case, first the circulation feed to the downstream centrifugal compressor is started and then the circulation feed to the upstream centrifugal compressor is started.

Moreover, in the said embodiment, the flow rate detector 6 measures the flow volume of the gas discharged | emitted from the gas compression part 2 directly, and the control apparatus 8 acquires the gas demand amount of a demand destination apparatus based on this measurement result. It was described.

However, the present invention is not limited to this, and the flow rate detector 6 instead measures the current consumption or power consumption of the motor 23, thereby indirectly measuring the flow rate of the gas discharged from the gas compression unit 2. You may measure. Even with such a configuration, the gas demand amount of the demand destination device can be obtained based on the measurement result.

Moreover, in the said embodiment, the structure provided with the centrifugal compressors 21 and 22 as the compression means of this invention was demonstrated.

However, the present invention is not limited thereto, and an axial compressor may be used as the compression means of the present invention.

Moreover, in the said embodiment, the structure provided with the motor as a drive means of this invention was demonstrated.

However, the present invention is not limited thereto, and an engine such as a diesel engine or a turbine such as a steam turbine may be used as the driving means of the present invention. In such a case, the gas demand of the demand destination device can be acquired by detecting the torque of the engine or the turbine instead of the flow rate detector 6.

Moreover, in the said embodiment, the structure with which the rotation speed of the motor 23 was fixed was demonstrated. However, this invention is not limited to this, For example, you may change the rotation speed of the motor 23 according to the suction amount of the gas of the gas compression part 2. In such a case, an inverter motor is often used as the motor 23.

Moreover, in the said embodiment, the diffuser 21h, 22h is arrange | positioned immediately after the impeller 21a, 22a, and demonstrated the structure which circulates and supplies gas to the diffuser 21h, 22h.

However, the present invention is not limited thereto, and for example, when an aperture flow path or the like exists between the impellers 21a and 22a and the diffusers 21h and 22h, the diffusers 21h and 22h or the above are provided. It can be circularly supplied between the diffusers 21h and 22h and the impellers 21a and 22a (that is, the diaphragm flow path).

In addition, the present invention can also be applied to a multi-stage multistage compressor in which a plurality of centrifugal compressors are arranged in multiple stages on a single shaft, and a multi-stage multistage compressor in which a centrifugal compressor is arranged through a gear increasing mechanism on each axis of the plurality of shafts. .

Moreover, as gas of this invention, air, nitrogen, oxygen, or a carbon dioxide gas can be used, for example.

According to the gas compression apparatus and the control method of the gas compression apparatus of this invention, load of a motor can fully be reduced while suppressing generation of surging in a centrifugal compressor, and energy consumption can be reduced.

One… … Inlet guide vanes (flow adjustment means), 2... … Gas compression section 21. … First centrifugal compressor (compression means), 22... … Second centrifugal compressor (compression means), 23... … Motor (drive means), 3... … First circulation supply control valve (circulation supply means), 4... … Second circulation supply control valve (circulation supply means), 5... … Discharge valve, 6.. … Flow rate detector (flow rate detecting means), 7... … Pressure detector (pressure detection means), 8.. … Control device (control means), 21a, 22a... … Impeller, 21h, 22h... … Diffuser, S… … Turbo Compressor (Gas Compressor)

Claims

A plurality of compression means having an impeller for imparting velocity energy to the gas and a diffuser for converting the velocity energy into pressure energy are arranged in series with respect to the flow direction of the gas, and the compressed gas is compressed through the plurality of compression means. As a gas compression device to supply to a predetermined demand destination,
Drive means for supplying power to the impeller;
Flow rate adjusting means for adjusting the flow rate of the gas sucked into the compression means located at the most upstream with respect to the flow direction of the gas;
Circulation supply means capable of circulating and supplying at least a portion of the gas discharged from the compression means located downstream from the flow direction of the gas between the diffuser of each compression means or between the diffuser and the impeller;
A control means for controlling at least the drive means, the flow rate adjusting means, and the circulation supply means,
The control means,
Controlling the flow rate adjusting means in accordance with the demand amount of the gas at the demand destination;
In each of the compression means, when the flow rate of the gas to be sucked is lower than a set value set based on the surging limit in the compression means, the circulation supply means is controlled to circulate a part of the gas to the compression means. Gas compression device.

The method of claim 1,
Pressure detection means for detecting the pressure of the gas discharged from the compression means located at the downstream, and flow rate detection means for detecting the flow rate of the gas discharged from the compression means located at the downstream,
And said control means controls said flow rate adjusting means by using at least a detection result of said pressure detecting means of said pressure detecting means and said flow rate detecting means as a demand amount of said gas of said demand destination.

The method of claim 1,
And said control means initiates the circulating supply of said gas by said circulation supply means stepwise from the downstreammost compression means toward the upstream compression means.

The method of claim 1,
And the set value is a sum of a flow rate of the surging limit in the compression means and a predetermined margin.

The method of claim 1,
The control means, when the demand amount of the gas at the demand destination is zero, maintains the suction of the gas from the compression means located most upstream with respect to the flow direction of the gas, and at the most downstream of the flow direction of the gas. A gas compression device for exhausting a part of the gas discharged from the located compression means without supplying it to the demander.

A plurality of compression means having an impeller for imparting velocity energy to the gas and a diffuser for converting the velocity energy into pressure energy are arranged in series with respect to the flow direction of the gas, and the compressed gas is compressed through the plurality of compression means. As a control method of a gas compression device to supply to a predetermined demand destination,
According to the demand amount of the gas at the demand destination, the flow rate of the gas sucked into the compression means located at the most upstream with respect to the flow direction of the gas is adjusted,
In each of the compression means, among the gases discharged from the compression means located downstream of the flow direction of the gas when the flow rate of the gas to be sucked falls below a set value set based on the surging limit in the compression means. The control method of the gas compression apparatus which circulates and supplies at least one part between the said diffuser of each compression means or between the said diffuser and the said impeller.

The method of claim 6,
Detecting a pressure and a flow rate of the gas discharged from the compression means located at the downstream side, and controlling the flow rate of the gas sucked into the compression means located at the most upstream by making at least the pressure as the required amount of the gas at the demand destination among the detection results; Control method of gas compression device.

The method of claim 6,
A control method of a gas compression device that starts circulating supply of the gas stepwise from the downstreammost compression means toward the upstream compression means.

The method of claim 6,
And the set value is a sum of a flow rate of the surging limit in the compression means and a predetermined margin.

The method of claim 6,
When the demand amount of the gas at the demand destination is zero, the suction of the gas in the compression means located most upstream with respect to the flow direction of the gas is maintained, and discharged from the compression means located downstream with respect to the flow direction of the gas. The control method of the gas compression apparatus which exhausts a part of gas which was not supplied to the said demand destination.