JPH0442555B2 - - Google Patents
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- Publication number
- JPH0442555B2 JPH0442555B2 JP28004488A JP28004488A JPH0442555B2 JP H0442555 B2 JPH0442555 B2 JP H0442555B2 JP 28004488 A JP28004488 A JP 28004488A JP 28004488 A JP28004488 A JP 28004488A JP H0442555 B2 JPH0442555 B2 JP H0442555B2
- Authority
- JP
- Japan
- Prior art keywords
- capacity
- slide valve
- valve
- bypass control
- bypass
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 claims description 8
- 230000007423 decrease Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 5
- 230000007704 transition Effects 0.000 description 3
- 230000003321 amplification Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
Landscapes
- Applications Or Details Of Rotary Compressors (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、負荷変動に合わせ容量制御するため
のスライド弁付きスクリユ圧縮機の容量制御方法
に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a capacity control method for a screw compressor with a slide valve for controlling capacity in accordance with load fluctuations.
（従来の技術）
従来、負荷変動に合わせて容量制御するように
したスライド弁付きスクリユ圧縮機として第４図
に示すものが公知である。(Prior Art) The screw compressor shown in FIG. 4 is known as a screw compressor with a slide valve that controls capacity according to load fluctuations.
このスライド弁付きスクリユ圧縮機は、容量制
御用のスライド弁１を備えたスクリユ圧縮機本体
２とその吸込管３と、逆止弁４を介在させた吐出
管５とを備え、油圧シリンダ６によりスライド弁
１を進退させるように形成してある。また、吐出
管５には吐出圧力を検出する圧力調節計７を取付
けて、この圧力調節計７による検出値を電々ポジ
シヨナ８に入力させている。さらに、油圧シリン
ダ６へは電磁式の４ポート３位置切換弁１１を介
して図示しない油圧源からの油圧を導くようにし
てあり、切換弁１１の制御を電々ポジシヨナ８に
より行わせる一方、油圧シリンダ６にスライド弁
１の開度を検出する開度発信器１０を取付けてこ
の開度発信器１０による検出値を電々ポジシヨナ
８にフイードバツクさせている。 This screw compressor with a slide valve includes a screw compressor main body 2 equipped with a slide valve 1 for capacity control, a suction pipe 3 thereof, and a discharge pipe 5 with a check valve 4 interposed therebetween. The slide valve 1 is formed to move forward and backward. Further, a pressure regulator 7 for detecting the discharge pressure is attached to the discharge pipe 5, and the detected value by the pressure regulator 7 is inputted to the electronic positioner 8. Further, hydraulic pressure from a hydraulic power source (not shown) is guided to the hydraulic cylinder 6 via an electromagnetic four-port three-position switching valve 11, and while the switching valve 11 is controlled by an electric positioner 8, the hydraulic cylinder An opening transmitter 10 for detecting the opening of the slide valve 1 is attached to the opening transmitter 6, and the detected value by the opening transmitter 10 is fed back to the electronic positioner 8.
そして、負荷側のガス使用量が増減したとき、
即ち負荷変動が生じたとき、圧縮機容量が一定で
あれば吐出圧力が増減するので、圧力調節計７と
開度発信器１０からの信号に基づいて電々ポジシ
ヨナ８により切換弁１１を制御させて、吐出圧力
が上昇すれば油圧シリンダ６によりスライド弁１
の開度を大きくして圧縮機容量を減少させ、逆に
吐出圧力が下がればスライド弁１の開度を小さく
して圧縮機容量を増大させて容量制御を行うよう
にしてある。 Then, when the amount of gas used on the load side increases or decreases,
That is, when load fluctuation occurs, the discharge pressure will increase or decrease if the compressor capacity is constant, so the switching valve 11 is controlled by the electronic positioner 8 based on the signals from the pressure regulator 7 and the opening transmitter 10. , when the discharge pressure increases, the hydraulic cylinder 6 closes the slide valve 1.
The opening degree of the slide valve 1 is increased to decrease the compressor capacity, and conversely, when the discharge pressure decreases, the opening degree of the slide valve 1 is decreased to increase the compressor capacity to perform capacity control.
（発明が解決しようとする課題）
本願出願人による特開昭61−190188号公報に記
載のように、一般的に、スライド弁１による圧縮
機容量の制御特性は、スライド弁全開に近い状
態、圧縮機容量でいえば約80〜100％では悪く、
圧縮ガスの種類により異なるが、例えばスライド
弁１の開度を０％から２％にすると、圧縮機容量
が約10％も減少する。(Problems to be Solved by the Invention) As described in Japanese Unexamined Patent Publication No. 1988-190188 by the applicant of the present application, the control characteristics of the compressor capacity by the slide valve 1 are generally such that the slide valve is in a state close to fully open, In terms of compressor capacity, about 80 to 100% is bad;
Although it varies depending on the type of compressed gas, for example, when the opening degree of the slide valve 1 is changed from 0% to 2%, the compressor capacity decreases by about 10%.
このため、上記従来のスライド弁１のみによる
容量制御方法では、スライド弁１の全閉付近で増
巾率が高過ぎて、制御系の安定性に著しく欠ける
という問題がある。 Therefore, in the conventional capacity control method using only the slide valve 1 described above, there is a problem that the amplification rate is too high near the fully closed position of the slide valve 1, resulting in a significant lack of stability in the control system.
本発明は、上記従来の問題点を課題としてなさ
れたもので、圧縮機容量が100％付近でも、微少
容量制御を可能とするスライド弁付きスクリユ圧
縮機の容量制御方法を提供しようとするものであ
る。 The present invention has been made to address the above-mentioned conventional problems, and aims to provide a capacity control method for a screw compressor with a slide valve that enables minute capacity control even when the compressor capacity is near 100%. be.
（課題を解決するための手段）
上記課題を解決するために、第１発明は、吐出
管より分岐してバイパス調節弁を介して吸込管に
至るバイパス管を設けたスライド弁付きスクリユ
圧縮機の容量の約70〜100％の範囲では、スライ
ド弁を全閉にして上記バイパス調節弁の開度調節
により容量制御をするバイパス制御を行い、上記
以外の範囲では上記バイパス調節弁を全閉にして
上記スライド弁により容量制御をするスライド弁
制御を行うようにした。(Means for Solving the Problems) In order to solve the above problems, a first invention provides a screw compressor with a slide valve that is provided with a bypass pipe that branches from a discharge pipe and reaches a suction pipe via a bypass control valve. In the range of approximately 70 to 100% of the capacity, bypass control is performed in which the slide valve is fully closed and the capacity is controlled by adjusting the opening of the bypass control valve, and in the range other than the above, the bypass control valve is fully closed. Slide valve control is performed to control the capacity using the slide valve.
また、第２発明は、上記スライド弁制御から上
記バイパス制御への切換え、またはその逆の切換
えに際し、上記スライド弁およびバイパス調節弁
をランプ関数的に開閉するようにした。 Further, in a second aspect of the present invention, the slide valve and the bypass control valve are opened and closed in a ramp function manner when switching from the slide valve control to the bypass control or vice versa.
（実施例）
次に、本発明の一実施例を図面にしたがつて説
明する。(Example) Next, an example of the present invention will be described with reference to the drawings.
第１図は、本発明に係る容量制御方法を適用し
たスライド弁付きスクリユ圧縮機を示し、第４図
に示す装置と共通する部分については、互いに同
一番号を付して説明を省略する。 FIG. 1 shows a screw compressor with a slide valve to which the capacity control method according to the present invention is applied, and parts common to the device shown in FIG. 4 are given the same numbers and explanations are omitted.
第４図の場合と異なり、このスクリユ圧縮機で
は、吐出管５から分岐してバイパス調節弁１２を
介して吸込管３に至るバイパス管１３を設けると
ともに、圧力調節計７により、この検出値に基づ
いて容量調節信号を演算器１４に入力し、この演
算器１４によりこの信号を演算し、電々ポジシヨ
ナ８とバイパス調節弁１２とに開度設定信号とし
て出力させるように形成してある。この電々ポジ
シヨナ８には、演算器１４からの開度設定信号と
開度発信器１０からの開度信号とを比較して、両
信号が同じになるように切換弁１１に対して駆動
信号を出力させている。 Unlike the case shown in FIG. 4, this screw compressor is provided with a bypass pipe 13 that branches from the discharge pipe 5 and reaches the suction pipe 3 via the bypass control valve 12. Based on this, a capacity adjustment signal is input to a calculator 14, which calculates this signal and outputs it to the electronic positioner 8 and bypass control valve 12 as an opening setting signal. The electronic positioner 8 compares the opening setting signal from the calculator 14 with the opening signal from the opening transmitter 10 and sends a drive signal to the switching valve 11 so that both signals are the same. It is outputting.
具体的には、例えば第２図（横軸：容量設定信
号値、縦軸：バイパス調節弁開度）、第３図（横
軸：容量設定信号値、縦軸：スライド弁開度）に
示すように、容量設定信号値が小さくなつてゆく
場合には70％を境にして、逆に大きくなつてゆく
場合には80％を境にして、この境界値より大きい
範囲ではスライド弁１の開度は０％にして、容量
設定信号値の増減に対応させてバイパス調節弁１
２の開度の縮小、増大により圧縮機容量を調節す
るバイパス制御を行う。これに対して、上記の境
界値70％または80％より小さい範囲ではバイパス
調節弁１２の開度は０％にして、容量設定信号値
の増減に対応させてスライド弁１の開度の縮小、
増大により圧縮機容量を調節するスライド弁制御
を行う。 Specifically, for example, it is shown in Fig. 2 (horizontal axis: capacity setting signal value, vertical axis: bypass control valve opening degree) and Fig. 3 (horizontal axis: capacity setting signal value, vertical axis: slide valve opening degree). As shown, when the capacity setting signal value decreases, the limit is set at 70%, and conversely, when it increases, the limit is set at 80%, and in a range larger than this limit value, the slide valve 1 is opened. Bypass control valve 1 is set to 0%, and the bypass control valve 1 is
Bypass control is performed to adjust the compressor capacity by reducing or increasing the opening degree. On the other hand, in a range smaller than the above-mentioned boundary value 70% or 80%, the opening degree of the bypass control valve 12 is set to 0%, and the opening degree of the slide valve 1 is reduced in response to an increase or decrease in the capacity setting signal value.
Slide valve control is performed to adjust the compressor capacity by increasing the compressor capacity.
なお、第２図中ａ、ｂは圧縮機容量80％、70％
に対応するバイパス調節弁１２の開度を示してい
る。 Note that a and b in Figure 2 indicate compressor capacity of 80% and 70%.
It shows the opening degree of the bypass control valve 12 corresponding to .
また、第３図中一点鎖線による曲線はスライ
ド弁１のみにより容量制御するとした場合の容量
設定信号値に対するスライド弁開度を示し、容量
設定信号値がわずかに変化するとスライド弁開度
は大きく変化している。 In addition, the curve indicated by the dashed-dotted line in Fig. 3 shows the slide valve opening degree with respect to the capacity setting signal value when the capacity is controlled only by slide valve 1, and when the capacity setting signal value changes slightly, the slide valve opening degree changes greatly. are doing.
さらに、容量設定信号値が小さくなつてゆく場
合と、大きくなつてゆく場合とで制御手段切換え
の境界値を変えてあるのは、制御手段切換え時に
容量設定信号値が不安定になつて変動してハンチ
ング現象が生じるのを防ぐためである。 Furthermore, the reason why the boundary value for switching the control means is changed depending on whether the capacitance setting signal value becomes smaller or larger is because the capacitance setting signal value becomes unstable and fluctuates when switching the control means. This is to prevent the hunting phenomenon from occurring.
ところで、制御手段切換え時にスライド弁１お
よびバイパス調節弁１２を瞬時に、ステツプ状に
容量設定信号値に対応した開度に出来れば問題は
ないが、現実にはある程度の長さの動作時間が必
要であり、その動作時間は、各弁によつて異な
り、バイパス調節弁１２の方がスライド弁１より
短い。したがつて、例えば容量設定信号値の増大
時の制御手段の切換えを、各弁の最短動作時間で
行おうとすると、スライド弁１が全閉になる前に
バイパス調節弁１２が開き、一時的に圧縮機容量
が適正値より減少する。即ち、制御手段切換時の
圧縮機容量が不安定となる。 By the way, there would be no problem if the slide valve 1 and the bypass control valve 12 could be opened instantaneously and stepwise to the opening corresponding to the capacity setting signal value when switching the control means, but in reality, a certain amount of operating time is required. The operating time differs depending on each valve, and the bypass control valve 12 is shorter than the slide valve 1. Therefore, for example, if you try to switch the control means when the capacity setting signal value increases in the shortest operating time of each valve, the bypass control valve 12 will open before the slide valve 1 is fully closed, and the temporary Compressor capacity is reduced from the appropriate value. That is, the compressor capacity becomes unstable when the control means is switched.
また、各制御弁の開度と容量の特性の相違によ
る圧縮機容量の変動が生じる。 Furthermore, the compressor capacity fluctuates due to differences in the opening degree and capacity characteristics of each control valve.
そこで、斯る不安定な状態を回避するために、
第４図、第５図に示すように、制御手段切換時の
各弁の開度指令をステツプ状に変動させずに、ラ
ンプ関数的に弁開度を時間経過とともに一定の変
化量で、即ち一定時間をかけて変化させ、この一
定時間を例えば動作速度が遅いスライド弁１の動
作時間に合わせた時間とする。 Therefore, in order to avoid such an unstable situation,
As shown in Fig. 4 and Fig. 5, the valve opening is changed by a constant amount over time using a ramp function, without changing the opening command of each valve in steps when switching the control means. It is changed over a certain period of time, and this certain period of time is set to, for example, a time that matches the operating time of the slide valve 1 whose operating speed is slow.
なお、第４図、第５図中、２点鎖線と実線部分
からなる曲線a1〜c2は容量設定信号に応じた制御
弁の開度を示し、例えば容量が増大傾向にあると
きには、容量が境界値になつた時刻t1でスライド
弁１をランプ関数的に閉じ始め、Δt1後に閉じる
一方、バイパス調節弁１２をランプ関数的に開き
始めて、この開度の直線と上記制御弁の開度曲線
とが交差した時点、即ち時刻t2でバイパス調節弁
１２の開度を上記開度曲線にしたがつて、即ち容
量調節信号にしたがつて制御する。これに対し
て、容量が減少傾向にあるときには、境界値にな
つた時刻t3でバイパス調節弁１２をランプ関数的
に閉じ始めΔt3後に閉じる一方、スライド弁１を
ランプ関数的に開き始めて、この開度の直線と上
記開度曲線とが交差した時点、即ち時刻t4でスラ
イド弁１の開度を上記開度曲線にしたがつて、即
ち容量調節信号にしたがつて制御する。したがつ
て、第４図、第５図に示す例では、
時刻０〜t1：スライド弁１による制御
時刻t1〜t2：スライド弁１からバイパス調節弁
１２への移行（バイパス調節弁１２：全閉→
B1）
’時刻t1〜t1＋Δt1：スライド弁１からバイパ
ス調節弁１２への移行（スライド弁１：S1→
全閉）
（但し、時刻t1＋Δt1でB2＝b1であれば、t2＝t1＋
Δt1となる。）
時刻t2〜t3：バイパス調節弁１２による制御
時刻t3〜t4：バイパス調節弁１２からスライド
弁１への移行（スライド弁１：全閉→S2）
’時刻t3〜t3＋Δt3：バイパス調節弁１２から
スライド弁１への移行（バイパス調節弁１２：
B2→全閉）
（但し、時刻t3＋Δt3でS2＝C2であれば、t4＝t3
＋Δt3となる。）
時刻t4〜：スライド弁１による制御
となる。 In FIGS. 4 and 5, the curves a 1 to c 2 consisting of the two-dot chain line and the solid line indicate the opening degree of the control valve according to the capacity setting signal. For example, when the capacity is increasing, the capacity At time t 1 when Δt reaches the boundary value, the slide valve 1 begins to close in a ramp function manner, and closes after Δt 1 , while the bypass control valve 12 begins to open in a ramp function manner, and the straight line of this opening and the opening of the control valve are At the time when the opening degree curve intersects, that is, at time t2 , the opening degree of the bypass control valve 12 is controlled according to the opening degree curve, that is, according to the capacity adjustment signal. On the other hand, when the capacity tends to decrease, the bypass control valve 12 starts to be closed in a ramp function at time t 3 when it reaches the boundary value, and is closed after Δt 3 , while the slide valve 1 starts to open in a ramp function, At the time when this opening degree straight line and the opening degree curve intersect, that is, at time t4 , the opening degree of the slide valve 1 is controlled according to the above opening degree curve, that is, according to the capacity adjustment signal. Therefore, in the example shown in FIG. 4 and FIG . : Fully closed →
B1) 'Time t1 to t1 + Δt1 : Transition from slide valve 1 to bypass control valve 12 (slide valve 1: S1→
fully closed) (However, if B 2 = b 1 at time t 1 + Δt 1 , t 2 = t 1 +
Δt becomes 1 . ) Time t 2 - t 3 : Control by bypass control valve 12 Time t 3 - t 4 : Transition from bypass control valve 12 to slide valve 1 (slide valve 1: fully closed → S2) 'Time t 3 - t 3 +Δt 3 : Transition from bypass control valve 12 to slide valve 1 (bypass control valve 12:
B2 → fully closed) (However, if S2 = C2 at time t 3 + Δt 3 , t 4 = t 3
+ Δt3 . ) Time t 4 ~: Control is performed by slide valve 1.
そして、具体的には、演算器１４に変化率制限
手段を内臓させて、弁開度変化速度を制限するよ
うにする。 Specifically, the computing unit 14 includes a rate-of-change limiting means to limit the rate of change in the valve opening.
なお、上記実施例では境界値を70％または80％
とした場合について説明したが、本発明は、この
数値に限るものではない。 In addition, in the above example, the boundary value is 70% or 80%.
Although the case has been described, the present invention is not limited to this value.
（発明の効果）
以上の説明より明らかなように、第１発明によ
れば、吐出管より分岐してバイパス調節弁を介し
て吸込管に至るバイパス管を設けたスライド弁付
きスクリユ圧縮機の容量の約70〜100％の範囲で
は、スライド弁を全閉にして上記バイパス調節弁
の開度調節により容量制御をするバイパス制御を
行い、上記以外の範囲では上記バイパス調節弁を
全閉にして上記スライド弁により容量制御をする
スライド弁制御を行うようにしてある。(Effects of the Invention) As is clear from the above description, according to the first invention, the capacity of the screw compressor with a slide valve is provided with a bypass pipe that branches from a discharge pipe and reaches a suction pipe via a bypass control valve. In the range of about 70 to 100% of the above, bypass control is performed in which the slide valve is fully closed and capacity is controlled by adjusting the opening of the bypass control valve.In the range other than the above, the bypass control valve is fully closed and the capacity is controlled by adjusting the opening of the bypass control valve. Slide valve control is used to control the capacity using a slide valve.
また、第２発明によれば、上記スライド弁制御
から上記バイパス制御への切換え、またはその逆
の切換えに際し、上記スライド弁およびバイパス
調節弁をランプ関数的に開閉するようにしてあ
る。 Further, according to the second invention, when switching from the slide valve control to the bypass control or vice versa, the slide valve and the bypass control valve are opened and closed in a ramp function manner.
このため、圧縮機容量が最大値に近い範囲にお
いても、微少容量制御が可能となり、負荷側のガ
ス使用量に見合つた適正な量のガスを安定して供
給することが出来るという効果を奏する。 Therefore, even in a range where the compressor capacity is close to the maximum value, minute capacity control is possible, and it is possible to stably supply an appropriate amount of gas commensurate with the amount of gas used on the load side.
第１図は本発明に係る容量制御方法を適用した
スライド弁付きスクリユ圧縮機の全体構成図、第
２図は容量設定信号値とバイパス弁開度の関係を
示す図、第３図は容量設定信号値とスライド弁開
度との関係を示す図、第４図、第５図は時間の経
過とともに変化する容量制御信号に対する弁開度
の変化を示す図、第６図は従来の容量制御方法を
適用したスライド弁付きスクリユ圧縮機の全体構
成図である。
１……スライド弁、２……スクリユ圧縮機本
体、３……吸込管、５……吐出管、１２……バイ
パス調節弁、１３……バイパス管。
Figure 1 is an overall configuration diagram of a screw compressor with a slide valve to which the capacity control method according to the present invention is applied, Figure 2 is a diagram showing the relationship between capacity setting signal value and bypass valve opening, and Figure 3 is capacity setting. A diagram showing the relationship between the signal value and the slide valve opening degree. Figures 4 and 5 are diagrams showing changes in the valve opening degree in response to the capacity control signal that changes over time. Figure 6 shows the conventional capacity control method. 1 is an overall configuration diagram of a screw compressor with a slide valve to which this is applied. DESCRIPTION OF SYMBOLS 1...Slide valve, 2...Screw compressor main body, 3...Suction pipe, 5...Discharge pipe, 12...Bypass control valve, 13...Bypass pipe.
Claims (1)
吸込管に至るバイパス管を設けたスライド弁付き
スクリユ圧縮機の容量の約70〜100％の範囲では、
スライド弁を全閉にして上記バイパス調節弁の開
度調節により容量制御をするバイパス制御を行
い、上記以外の範囲では上記バイパス調節弁を全
閉にして上記スライド弁により容量制御をするス
ライド弁制御を行うことを特徴とするスライド弁
付きスクリユ圧縮機の容量制御方法。 ２ 上記スライド弁制御から上記バイパス制御へ
の切換え、またはその逆の切換えに際し、上記ス
ライド弁およびバイパス調節弁をランプ関数的に
開閉するようにしたことを特徴とする特許請求の
範囲第１項に記載のスライド弁付きスクリユ圧縮
機の容量制御方法。[Claims] 1. In the range of about 70 to 100% of the capacity of a screw compressor with a slide valve, which is provided with a bypass pipe that branches from the discharge pipe and reaches the suction pipe via the bypass control valve,
Bypass control is performed in which the slide valve is fully closed and capacity is controlled by adjusting the opening of the bypass control valve, and in a range other than the above, the bypass control valve is fully closed and capacity is controlled by the slide valve. A capacity control method for a screw compressor with a slide valve, characterized by performing the following steps. 2. According to claim 1, the slide valve and the bypass control valve are opened and closed in a ramp function manner when switching from the slide valve control to the bypass control or vice versa. A capacity control method for a screw compressor with a slide valve as described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28004488A JPH02125990A (en) | 1988-11-04 | 1988-11-04 | Capacity control for screw compressor with slide valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28004488A JPH02125990A (en) | 1988-11-04 | 1988-11-04 | Capacity control for screw compressor with slide valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02125990A JPH02125990A (en) | 1990-05-14 |
| JPH0442555B2 true JPH0442555B2 (en) | 1992-07-13 |
Family
ID=17619519
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28004488A Granted JPH02125990A (en) | 1988-11-04 | 1988-11-04 | Capacity control for screw compressor with slide valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02125990A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0491282U (en) * | 1990-12-26 | 1992-08-10 | ||
| TW299393B (en) * | 1995-03-09 | 1997-03-01 | Sanyo Electric Co |
-
1988
- 1988-11-04 JP JP28004488A patent/JPH02125990A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02125990A (en) | 1990-05-14 |
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