JP3578660B2

JP3578660B2 - Centrifugal compressor

Info

Publication number: JP3578660B2
Application number: JP12558399A
Authority: JP
Inventors: 幸二中川; 泰男浦木
Original assignee: 株式会社日立インダストリイズ
Priority date: 1999-05-06
Filing date: 1999-05-06
Publication date: 2004-10-20
Anticipated expiration: 2019-05-06
Also published as: JP2000314396A

Description

【０００１】
【発明の属する技術分野】
本発明は流量制御装置を有する遠心圧縮機に係り、特に小流量運転時の特性を改善するのに好適な流量制御装置を有する遠心圧縮機に関する。
【０００２】
【従来の技術】
遠心圧縮機の羽根車入口の上流に、流量制御装置として吸込ダンパあるいはインレットガイドベーンが広く用いられている。吸込ダンパは、たとえば、エッカート著アキシャルウントラディアルコンプレッソーレン第２版スプリンガー１９６１年４１８頁図４３５に示されているように、羽根車上流の流路に設けた断面積を可変とする絞り機構である。そして、圧力損失を発生させ、吸込ダンパを含めた遠心圧縮機の圧力上昇を減少させて流量を制御する。
【０００３】
インレットガイドベーン装置では、たとえば、生井、井上著ターボ送風機と圧縮機初版コロナ社昭和６３年８月６７６頁図１５．１６に示されているように、羽根車上流の流路に複数のベーンを設け、このベーンが流れに羽根車の回転方向の旋回を与えている。羽根車の消費動力と圧力上昇を同時に低減させて、遠心圧縮機の流量を制御する。
【０００４】
なお、上記インレットガイドベーン等に用いられるベーン起因する振動を防止するために、ベーンに湾曲フィンを取り付けて羽根車の振動を防止することが、特開平７―１３９４９７号公報に示されている。
【０００５】
【発明が解決しようとする課題】
上記従来技術に記載の圧縮機の流量制御装置の中で、エッカート著に記載の吸込みダンパは、可動ベーンを１枚有するだけであり、構造が単純な利点を有している。しかしながら、吸込ダンパで圧力損失を発生させているので、エネルギーの無駄遣いになる。また、流れを羽根車入口断面の片方の側に偏らせているので、騒音や振動が発生するおそれがある。このため、大容量の機種ではほとんど使用できない。
【０００６】
また、生井著に記載のインレットガイドベーンは、４枚以上の可動ベーンを有し、エネルギー損失が少ない利点がある。そして、羽根車入口断面における流れが均一に近く、騒音や振動低減を低減できる。しかしながら、多数のベーンを同期して回転させるために構造が複雑になり、大型や大容量の機種では使用可能であるが、小容量機にはコスト面で不向きである。
【０００７】
さらに、上記特開平７―１３９４９７号公報に記載のものは、構造が複雑であり、コストが増大するという不具合がある。なお、羽根車の入口断面積が羽根車の上流側の断面積に比べて著しく小さい場合には、上流側を絞って流量を減少させるために、エネルギー損失が増大したり、羽根車入口断面における流れの不均一が増大するという不具合を生じるおそれがある。
【０００８】
本発明は、上記従来の技術の不具合に鑑みなされたものであり、その目的は、遠心圧縮機において、簡単な構成で小流量時の特性を向上させることにある。つまり、吸込ダンパにより流量制御する遠心圧縮機において、小流量運転時のエネルギー損失を低減するとともに、流れの偏流に起因する騒音や振動を低減することを目的とする。
【０００９】
【課題を解決するための手段】
上記目的を達成するための本発明の第１の特徴は、遠心羽根車と、この遠心羽根車の吸い込み側に回動可能に設けられた流量調整手段とを備えた遠心圧縮機において、流量調整手段は半円状の互いに逆方向に回転可動な２枚のベーンを有し、流量調整手段と遠心羽根車間に吸込み流路を縮小する面積調整手段を設け、この面積調整手段の内径をほぼ羽根車入口径程度とし、面積調整手段が取付けられる配管の内径と面積調整手段の内径との差を遠心羽根車の出口幅に応じて変化させたものである。
【００１０】
上記目的を達成するための本発明の第２の特徴は、遠心羽根車と、この遠心羽根車の吸い込み側に回動可能に設けられた流量調整手段とを備えた遠心圧縮機において、流量調整手段は円板状のベーンを有し、流量調整手段と遠心羽根車間に吸込み流路を縮小する面積調整手段を設け、この面積調整手段の内径をほぼ羽根車入口径程度とし、面積調整手段が取付けられる配管の内径と面積調整手段の内径との差を遠心羽根車の出口幅に応じて変化させたものである。
【００１１】
そして、いずれの特徴においても、面積調整手段を流量調整手段に近接して設け、この面積調整手段に対向する端部を球面状に形成することが望ましい。
【００１２】
【発明の実施の形態】
以下、本発明のいくつかの実施例を図面を用いて説明する。図１および図２は、本発明の第１の実施例に関する図であり、図１は本発明に係る遠心圧縮機の羽根車回転軸を含む縦断面であり、図２は図１に示した実施例に用いられる流量制御装置の水平断面図及び側面図である。遠心圧縮機１００は、羽根車１、ディフューザ３、これらを収容するケーシング４、および吸込流路が形成された配管５を備えている。そして、吸込み流路には流量調整板６が配置されており、流量調整板６は回転運動駆動源であるアクチュエータ８により駆動される。流量調整板６とアクチュエータ８は、流量調整装置２０を構成する。
【００１３】
羽根車１の入口径Ｄ１は、吸込流路５の直径ＤＳより小さい。流量調整板６は半円状の板２枚を有し、アクチュエータ８により互いに逆方向に回転駆動される。これら２枚の流量調整板６を全閉状態にすると、吸込流路の大部分を閉鎖可能である。また、流量調整板６を全開状態にすると、吸込流路の大部分を開放可能である。流量調整板６と羽根車入口の間には、円筒形状の面積調整スペーサ７が取り付けられている。面積調整スペーサ７の流量調整板６に面した端面は、流量調整板６が回転して形成する球面に近接する球面状に加工されている。さらに、面積調整スペーサ７の内径は、羽根車１の入口径Ｄ１前後の寸法に加工されている。
【００１４】
作動ガスは、矢印２の方向の流れとなって、圧縮機に吸い込まれる。遠心圧縮機１００を起動するときは、これら２枚の流量調整板６を全閉状態にし、吸込流路の断面積の大部分を閉鎖する。吸込流路の大部分を閉鎖するので、遠心圧縮機の駆動機の起動動力を低減できる。また、流量調整板６を全開状態にして、吸込流路の大部分を開放できるから、全開状態では流量調整装置によるエネルギー損失を最小限に抑えられる。
【００１５】
図２に、流量調整板６ｕ、６ｄの動作を示す。図２の左側の図は、図１の吸込流路５の水平断面図である。図２の右側の図はその側面図であり、下流側から見た図である。作動ガスは、左側の図の矢印２のように流入する。流量調整板を全開および全閉にした状態では、従来の流量調整板が１枚のダンパと同じ流れ状態になる。しかし、全開と全閉の中間開度では違いが著しく、旋回流を発生させることができる。矢印ａ、ｂ、ｃ、ａ_ａ、ｂ_ａ、ｃ_ａは代表的な流れを示す。矢印ａ、ｂ、ｃは断面の上半分側の流量調整板６ｕに流入する流れ、ａ_ａ、ｂ _ａ、ｃ_ａは断面の下半分側の流量調整板６ｄに流入する流れである。
【００１６】
初めに、上半分側の流量調整板６ｕに流入する流れａ、ｂ、ｃに着目する。配管５の壁面近くの流れａは、壁面５と流量調整板６ｕの間の隙間を通過し、流量調整板６ｕにガイドされて、右から左に向かう速度成分を持つ。流れｂは、下側に潜り込み、その際、上から下に向かう速度成分を持つ。下側に潜り込んだ流れは、下半分側の流量調整板６ｄににガイドされて、左から右に向かう速度成分を持つ。面積調整スペーサ７が流量調整板６ｕに面する端部は、流量調整板６ｕが回転して形成する球面に近接する球面状に加工されているので、流れｃは流れｂと同様に下側に潜り込み、流れｂと合流する。
【００１７】
下半分側の流量調整板６ｄに流入する流れａ_ａ、ｂ_ａ、ｃ_ａは、下流側から見て流路断面の中心に関して点対称になるので、旋回流が発生する。面積調整スペーサ７がない場合には、流れｃは壁面と流量調整板の間の隙間を通過するので流量調整効果が減少する。しかし、面積調整スペーサ７があると、流れｃは流れｂに合流し、旋回流が強力になる。旋回流が強力になることは、予旋回によるエネルギー損失防止効果が大であることであり、また、羽根車における昇圧作用（オイラーヘッド）の低下を意味する。
【００１８】
図３に、本発明に係る遠心圧縮機の他の実施例の縦断面図を示す。この実施例は、図１に示した第１の実施例とケーシング４、吸込流路５および流量制御板６の寸法が同じである。遠心圧縮機の流量は第１の実施例より少ないが、昇圧能力は等しい。そして、この遠心圧縮機に用いる羽根車１_ａの外径は羽根車１と同等であるが、入口径や羽根車出口幅は羽根車１より小さい。本実施例では、面積調整スペーサ７の内側の径を羽根車１_ａの入口径にあわせている。羽根車出口幅ｂは第１の実施例より小さくなっているので、ディフューザ幅ｂ_ａが羽根車１_ａに合うように、ディフューザ板９の厚さを変更している。
【００１９】
この理由を図４および図５を用いて説明する。図４および図５は、第１の実施例の作用を説明する図２に対応する図である。図４では、上記第１の実施例と同じ内径の面積調整スペーサ７を用いている。本実施例においても、面積調整スペーサ７の流量調整板６に面した端面を流量調整板６が回転して形成する球面に近接する球面状に加工しているので、流れｃは、流れｂと同様に下側に潜り込み、流れｂと合流する。
【００２０】
流れａは壁面と流量調整板６の間の隙間を通過するが、羽根車１_ａの流量が少ないので、流速の絶対値が小さい。したがって旋回速度が減少し、流量調整効果が減少する。流量調整効果の減少を補うため、流量調整板６の開度をさらに減少させ、図中の点線で示した位置まで流量調整板を閉じると、流れａ_ｂは壁面と流量調整板の間の隙間を通過せざるを得ず、エネルギー損失が増加する。このことは羽根車入口流れの不均一性が増加し、騒音や振動が増加するおそれがあることを示している。
【００２１】
流量調整板６の開度をさらに減少させると、このような不具合を生じるので、流量調整板６の開度をこれ以上減少させずに、流量を調整する。そのため、図５に示した実施例では、羽根車１_ａの入口径に合わせて内径を減少させた面積調整スペーサ７を用いている。この場合、流れａ_ｂは壁面と流量調整板の間の隙間を通過できない。
【００２２】
その結果、流量調整効果が減少せず、流量調整板の開度をこれ以上減少させる必要がない。また、流れａ_ｂのエネルギー損失も増加しない。したがって、羽根車の入口流れの不均一が増加せず、騒音や振動が増大することを防止できる。本実施例は、第１の実施例の羽根車、ディフューザおよび面積調整スペーサの寸法を変えるだけであり、変更に要するコストが大きい吸込流路、ケーシング及び流量調整板を変更する必要がなく、安価である。また、第１の実施例と同様に、振動や騒音を引き起こすことなく、流量を容易に制御できる。
【００２３】
本発明のさらに他の実施例を図６に示す。図６が、図１及び図３に示した実施例と異なる点は、流量調整板を１枚にしたことにある。なお、この図６においても、流量調整手段と羽根車間には面積調整スペーサが設けられている。本実施例は、第１、第２の実施例より流量調整作用の効果は減少するが構造を簡便にできる。
【００２４】
流量制御は流量調整板による圧力損失のみによって行われるので、一般的にはエネルギー消費が流量調整板２枚の場合より大きい。しかし、流量調整板下流に面積調整スペーサ７を設けて流路を絞っているので、流量調整板の流量調整作用が大きい。また、羽根車入口流れの均一性も改善できる。この結果、面積調整スペーサ７がない場合と比較すると、エネルギー消費、騒音および振動特性を改善できる。本実施例は、簡便な構造と信頼性が必要な機種に好適である。
【００２５】
【発明の効果】
本発明によれば、羽根車入口の上流側に流量制御装置を有する遠心圧縮機において、２枚の可動ベーンを備えた流量制御装置を設けたので、小流量運転時の消費動力特性を向上し、不均一流れによる騒音と振動の増加を低減できる。
【図面の簡単な説明】
【図１】本発明に係る遠心圧縮機の一実施例の縦断面図。
【図２】図１に示した実施例に用いる吸込流路と流量制御装置部の水平断面図。
【図３】本発明に係る遠心圧縮機の他の実施例の縦断面図。
【図４】図３に示した実施例に用いる吸込流路と流量制御装置部の水平断面図。
【図５】図３に示した実施例に用いる吸込流路と流量制御装置部の他の実施例の水平断面図。
【図６】本発明に係る遠心圧縮機のさらに他の実施例の縦断面図。
【符号の説明】
１…羽根車、２…流れ、
３…ディフューザ、４…ケーシング、
５…吸込流路、６…流量調整板、
７…面積調整スペーサ、８…アクチュエータ、
９…ディフューザ板。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a centrifugal compressor having a flow rate control device, and more particularly to a centrifugal compressor having a flow rate control device suitable for improving characteristics during small flow rate operation.
[0002]
[Prior art]
A suction damper or an inlet guide vane is widely used as a flow control device upstream of an impeller inlet of a centrifugal compressor. As shown in FIG. 435, the suction damper is, for example, an axial und radial compression compressor by Eckert, second edition, Springer, page 418, 418. As shown in FIG. . Then, a pressure loss is generated, and the flow rate is controlled by reducing the rise in pressure of the centrifugal compressor including the suction damper.
[0003]
In the inlet guide vane device, for example, a turbo blower and a compressor by Ikui and Inoue First edition Corona Co., Ltd. August 1988, p. 676 As shown in FIG. This vane provides the flow with a swirl in the direction of rotation of the impeller. The power consumption of the impeller and the rise in pressure are simultaneously reduced to control the flow rate of the centrifugal compressor.
[0004]
Japanese Unexamined Patent Publication (Kokai) No. 7-139497 discloses that a curved fin is attached to a vane to prevent vibration of an impeller in order to prevent vibration caused by a vane used for the inlet guide vane or the like.
[0005]
[Problems to be solved by the invention]
Of the compressor flow control devices described in the prior art, the suction damper described by Eckert has only one movable vane, and has the advantage of a simple structure. However, since pressure loss is generated by the suction damper, energy is wasted. Further, since the flow is deflected to one side of the impeller entrance cross section, noise or vibration may be generated. For this reason, it cannot be used with a large-capacity model.
[0006]
The inlet guide vane described by Ikui has four or more movable vanes, and has an advantage of low energy loss. Then, the flow at the impeller entrance cross section is nearly uniform, and noise and vibration reduction can be reduced. However, since a large number of vanes are rotated synchronously, the structure becomes complicated and can be used in a large-sized or large-capacity model, but is not suitable for a small-capacity machine in terms of cost.
[0007]
Furthermore, the structure described in Japanese Patent Application Laid-Open No. 7-139497 has a problem that the structure is complicated and the cost is increased. If the inlet cross-sectional area of the impeller is significantly smaller than the cross-sectional area on the upstream side of the impeller, energy loss increases to reduce the flow rate by narrowing the upstream side, There is a possibility that a problem that the unevenness of the flow increases may occur.
[0008]
The present invention has been made in view of the above-mentioned disadvantages of the related art, and has as its object to improve the characteristics of a centrifugal compressor at a small flow rate with a simple configuration. That is, in a centrifugal compressor in which the flow rate is controlled by the suction damper, it is an object to reduce energy loss at the time of small flow rate operation and reduce noise and vibration caused by drift of the flow.
[0009]
[Means for Solving the Problems]
A first feature of the present invention to achieve the above object is to provide a centrifugal compressor including a centrifugal impeller and a flow rate adjusting means rotatably provided on a suction side of the centrifugal impeller. The means has two semi-circular vanes rotatable in opposite directions, and is provided with an area adjusting means for reducing the suction flow path between the flow rate adjusting means and the centrifugal impeller. The diameter is about the vehicle inlet diameter, and the difference between the inner diameter of the pipe to which the area adjusting means is attached and the inner diameter of the area adjusting means is changed according to the outlet width of the centrifugal impeller .
[0010]
A second feature of the present invention to achieve the above object is that a centrifugal compressor provided with a centrifugal impeller and a flow rate adjusting means rotatably provided on a suction side of the centrifugal impeller, means has a disc-shaped vane, the area adjustment means for reducing the suction flow path between the flow rate adjusting means and the centrifugal impeller provided with substantially the impeller inlet diameter of about the inner diameter of the area adjustment unit, the area adjustment means The difference between the inside diameter of the pipe to be attached and the inside diameter of the area adjusting means is changed according to the exit width of the centrifugal impeller .
[0011]
Then, in either aspect, it provided adjacent the surface product adjusting means the flow regulating mechanism, it is desirable to form the end opposite to the area adjustment means spherically.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, some embodiments of the present invention will be described with reference to the drawings. 1 and 2 are diagrams relating to a first embodiment of the present invention. FIG. 1 is a longitudinal section including an impeller rotation shaft of a centrifugal compressor according to the present invention, and FIG. It is a horizontal sectional view and a side view of a flow control device used for an example. The centrifugal compressor 100 includes an impeller 1, a diffuser 3, a casing 4 for housing the impeller 1, a diffuser 3, and a pipe 5 in which a suction channel is formed. A flow rate adjusting plate 6 is disposed in the suction flow path, and the flow rate adjusting plate 6 is driven by an actuator 8 which is a driving source for rotational movement. The flow rate adjusting plate 6 and the actuator 8 constitute a flow rate adjusting device 20.
[0013]
The inlet diameter D1 of the impeller 1 is smaller than the diameter DS of the suction passage 5. The flow rate adjusting plate 6 has two semicircular plates, and is rotationally driven by actuators 8 in opposite directions. When these two flow control plates 6 are fully closed, most of the suction flow path can be closed. When the flow rate adjusting plate 6 is fully opened, most of the suction flow path can be opened. A cylindrical area adjusting spacer 7 is attached between the flow rate adjusting plate 6 and the impeller inlet. The end face of the area adjusting spacer 7 facing the flow adjusting plate 6 is processed into a spherical shape close to a spherical surface formed by rotating the flow adjusting plate 6. Further, the inner diameter of the area adjusting spacer 7 is processed to a size around the inlet diameter D1 of the impeller 1.
[0014]
The working gas flows in the direction of arrow 2 and is sucked into the compressor. When starting the centrifugal compressor 100, the two flow rate adjusting plates 6 are fully closed, and most of the cross-sectional area of the suction flow path is closed. Since most of the suction flow path is closed, the starting power of the drive of the centrifugal compressor can be reduced. Further, since the flow control plate 6 can be fully opened to open most of the suction flow path, energy loss due to the flow control device can be minimized in the fully opened state.
[0015]
FIG. 2 shows the operation of the flow rate adjusting plates 6u and 6d. 2 is a horizontal cross-sectional view of the suction flow channel 5 of FIG. The figure on the right side of FIG. 2 is a side view thereof, and is a view seen from the downstream side. The working gas flows in as indicated by arrow 2 in the figure on the left. When the flow control plate is fully opened and fully closed, the conventional flow control plate is in the same flow state as one damper. However, there is a remarkable difference between the fully opened and fully closed intermediate openings, and a swirling flow can be generated. Arrows _{_{a, b, c, a a}} , b a, c a shows a typical flow. Arrows a, b, c are flow entering the flow regulating plate 6u of the upper half of the cross-section _side, _{a a,} b _a, the _{c a} a flow entering the flow regulating plate 6d of the lower half of the cross-section side.
[0016]
First, attention is paid to the flows a, b, and c flowing into the upper half-side flow rate adjusting plate 6u. The flow a near the wall surface of the pipe 5 passes through a gap between the wall surface 5 and the flow control plate 6u, is guided by the flow control plate 6u, and has a velocity component from right to left. The stream b sinks down, with a velocity component going from top to bottom. The flow sunk into the lower side is guided by the flow adjustment plate 6d on the lower half side, and has a velocity component from left to right. Since the end of the area adjusting spacer 7 facing the flow rate adjusting plate 6u is processed into a spherical shape close to a spherical surface formed by the rotation of the flow rate adjusting plate 6u, the flow c flows downward like the flow b. Sinks and merges with stream b.
[0017]
Flow a _a which flows into the flow regulating plate 6d of the lower half _side, b _a, c _a is, since the point symmetry with respect to the center of the channel cross section as viewed from the downstream side, swirling flow is generated. In the case where the area adjusting spacer 7 is not provided, the flow c passes through the gap between the wall surface and the flow adjusting plate, and the flow adjusting effect is reduced. However, when the area adjusting spacer 7 is provided, the flow c merges with the flow b, and the swirling flow becomes strong. The strong swirling flow means that the effect of preventing energy loss due to the pre-swirl is large, and also means that the boosting action (Euler head) of the impeller is reduced.
[0018]
FIG. 3 shows a longitudinal sectional view of another embodiment of the centrifugal compressor according to the present invention. This embodiment is the same as the first embodiment shown in FIG. 1 in the dimensions of the casing 4, the suction passage 5, and the flow control plate 6. The flow rate of the centrifugal compressor is smaller than that of the first embodiment, but the boosting capacity is equal. The outer diameter of the impeller 1 _a used in this centrifugal compressor is the same as that of the impeller 1, but the inlet diameter and the impeller outlet width are smaller than the impeller 1. In this embodiment, the combined diameter of the inner area adjustment spacer 7 to inlet diameter of the impeller 1 _a. Since the impeller outlet width b is smaller than the first embodiment, the diffuser width b _a is to fit to the impeller 1 _a, which changes the thickness of the diffuser plate 9.
[0019]
The reason will be described with reference to FIGS. 4 and 5 are diagrams corresponding to FIG. 2 for explaining the operation of the first embodiment. In FIG. 4, an area adjusting spacer 7 having the same inner diameter as that of the first embodiment is used. Also in the present embodiment, since the end face of the area adjusting spacer 7 facing the flow rate adjusting plate 6 is processed into a spherical shape close to a spherical surface formed by the rotation of the flow rate adjusting plate 6, the flow c becomes the flow b. Similarly, it sinks below and merges with the stream b.
[0020]
Flow a passes through the gap between the wall and the flow rate adjusting plate 6, but the flow rate of the impeller 1 _a is small, the absolute value of the flow velocity is small. Therefore, the turning speed decreases, and the flow rate adjustment effect decreases. In order to compensate for the decrease in the flow rate adjustment effect, the opening of the flow rate adjustment plate 6 is further reduced, and the flow adjustment plate is closed to the position shown by the dotted line in the figure, and the flow _ab passes through the gap between the wall surface and the flow adjustment plate. Energy loss. This indicates that the non-uniformity of the impeller inlet flow increases, and that noise and vibration may increase.
[0021]
If the opening degree of the flow control plate 6 is further reduced, such a problem occurs. Therefore, the flow rate is adjusted without further reducing the opening degree of the flow control plate 6. Therefore, in the embodiment shown in FIG. 5, using the area adjustment spacer 7 having a reduced inner diameter to fit the inlet diameter of the impeller 1 _a. In this case, the flow _ab cannot pass through the gap between the wall surface and the flow control plate.
[0022]
As a result, the flow control effect is not reduced, and there is no need to further reduce the opening of the flow control plate. Also, the energy loss of stream _ab does not increase. Therefore, the non-uniformity of the inlet flow of the impeller does not increase, and it is possible to prevent an increase in noise and vibration. In this embodiment, only the dimensions of the impeller, the diffuser and the area adjusting spacer of the first embodiment are changed, and there is no need to change the suction passage, the casing, and the flow rate adjusting plate which require a large cost for the change. It is. Further, similarly to the first embodiment, the flow rate can be easily controlled without causing vibration or noise.
[0023]
FIG. 6 shows still another embodiment of the present invention. FIG. 6 differs from the embodiment shown in FIG. 1 and FIG. 3 in that the number of flow control plates is one. In FIG. 6, an area adjusting spacer is provided between the flow rate adjusting means and the impeller. In this embodiment, the effect of the flow rate adjusting action is reduced as compared with the first and second embodiments, but the structure can be simplified.
[0024]
Since the flow rate control is performed only by the pressure loss caused by the flow rate adjusting plates, the energy consumption is generally larger than in the case of two flow rate adjusting plates. However, since the flow path is narrowed by providing the area adjusting spacer 7 downstream of the flow adjusting plate, the flow adjusting effect of the flow adjusting plate is large. In addition, the uniformity of the impeller inlet flow can be improved. As a result, energy consumption, noise and vibration characteristics can be improved as compared with the case where the area adjusting spacer 7 is not provided. This embodiment is suitable for a model requiring a simple structure and reliability.
[0025]
【The invention's effect】
According to the present invention, in the centrifugal compressor having the flow control device on the upstream side of the impeller inlet, the flow control device including the two movable vanes is provided. In addition, an increase in noise and vibration due to uneven flow can be reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of one embodiment of a centrifugal compressor according to the present invention.
FIG. 2 is a horizontal sectional view of a suction channel and a flow control unit used in the embodiment shown in FIG. 1;
FIG. 3 is a longitudinal sectional view of another embodiment of the centrifugal compressor according to the present invention.
FIG. 4 is a horizontal sectional view of a suction channel and a flow control unit used in the embodiment shown in FIG. 3;
FIG. 5 is a horizontal sectional view of another embodiment of the suction flow path and the flow control device used in the embodiment shown in FIG. 3;
FIG. 6 is a longitudinal sectional view of still another embodiment of the centrifugal compressor according to the present invention.
[Explanation of symbols]
1. Impeller, 2. Flow,
3 ... diffuser, 4 ... casing,
5: suction channel, 6: flow rate adjusting plate,
7 ... area adjustment spacer, 8 ... actuator,
9 ... diffuser plate.

Claims

In a centrifugal compressor including a centrifugal impeller and a flow rate adjusting means rotatably provided on a suction side of the centrifugal impeller, the flow rate adjusting means is a semicircular two-rotationally movable two-pieces. And an area adjusting means for reducing a suction flow path between the flow rate adjusting means and the centrifugal impeller is provided. An inner diameter of the area adjusting means is substantially equal to the impeller inlet diameter, and the area adjusting means is attached. A centrifugal compressor characterized in that the difference between the inner diameter of the pipe and the inner diameter of the area adjusting means is changed according to the outlet width of the centrifugal impeller .

In a centrifugal compressor including a centrifugal impeller and a flow rate adjusting means rotatably provided on a suction side of the centrifugal impeller, the flow rate adjusting means has a disc-shaped vane, and the flow rate adjusting means And an area adjusting means for reducing a suction flow path between the centrifugal impeller and the inner diameter of the area adjusting means is set to approximately the same as the impeller inlet diameter, and an inner diameter of a pipe to which the area adjusting means is attached and an inner diameter of the area adjusting means A centrifugal compressor characterized in that the difference from the above is changed according to the exit width of the centrifugal impeller .

In a centrifugal compressor comprising a centrifugal impeller and a flow rate adjusting means rotatably provided on the suction side of the centrifugal impeller, the flow rate adjusting means is a semicircular two-rotatably movable two-way rotating member. And an area adjusting means for reducing a suction flow path between the flow rate adjusting means and the centrifugal impeller. An inner diameter of the area adjusting means is approximately equal to the impeller inlet diameter, and the area adjusting means is attached. A centrifugal compressor characterized in that the difference between the inner diameter of the pipe and the inner diameter of the area adjusting means increases as the outlet width of the centrifugal impeller decreases.

In a centrifugal compressor including a centrifugal impeller and flow rate adjusting means rotatably provided on a suction side of the centrifugal impeller, the flow rate adjusting means has a disc-shaped vane, and the flow rate adjusting means And an area adjusting means for reducing a suction flow path between the centrifugal impeller and the inner diameter of the area adjusting means is set to substantially the same as the impeller inlet diameter. The centrifugal compressor is characterized in that the difference from the centrifugal compressor is increased as the outlet width of the centrifugal impeller decreases.

The centrifugal compression according to any one of claims 1 to 4, wherein the area adjusting means is provided close to the flow rate adjusting means, and an end facing the area adjusting means is formed in a spherical shape. Machine.