JPH04159491A - Method and device for controlling volume of screw compressor - Google Patents
Method and device for controlling volume of screw compressorInfo
- Publication number
- JPH04159491A JPH04159491A JP28427990A JP28427990A JPH04159491A JP H04159491 A JPH04159491 A JP H04159491A JP 28427990 A JP28427990 A JP 28427990A JP 28427990 A JP28427990 A JP 28427990A JP H04159491 A JPH04159491 A JP H04159491A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- compressor
- load
- control valve
- load operation
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 15
- 238000001514 detection method Methods 0.000 claims description 6
- 230000000694 effects Effects 0.000 abstract description 8
- 230000007423 decrease Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 238000007664 blowing Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 101100129500 Caenorhabditis elegans max-2 gene Proteins 0.000 description 1
- 101150006573 PAN1 gene Proteins 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 230000003584 silencer Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/24—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
- F04B49/065—Control using electricity and making use of computers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/08—Regulating by delivery pressure
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Computer Hardware Design (AREA)
- Control Of Positive-Displacement Pumps (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、吸入側にオンオフ式制御弁を備えたスクリュ
ー圧縮機の容量制御方法及び装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for controlling the capacity of a screw compressor equipped with an on-off type control valve on the suction side.
従来のオンオフ式制御弁を備えたスクリュー圧縮機の容
量制御装置は、例えば特公平1−33676号公報など
に記載のように、オンオフ式制御弁と吐出放風弁を有し
、全負荷運転により吐出側圧力を上昇させ、ある設定値
を越えるとオンオフ制御弁を閉じかつ放風弁を開放して
無負荷運転に切替え、その後吐出側の貯気槽内圧力が低
下しある設定値以下になるとオンオフ制御弁を開にする
と共に放風弁を閉じて全負荷運転に切替えるようにして
いる。A conventional capacity control device for a screw compressor equipped with an on-off type control valve has an on-off type control valve and a discharge blow-off valve, as described in, for example, Japanese Patent Publication No. 1-33676. The pressure on the discharge side is increased, and when it exceeds a certain set value, the on/off control valve is closed and the air discharge valve is opened to switch to no-load operation, and then when the pressure inside the storage tank on the discharge side decreases and becomes below a certain set value. The on-off control valve is opened and the blowoff valve is closed to switch to full-load operation.
このような従来の装置では、圧縮機の吐出側圧力を圧力
スイッチで検出し、この検出値に応じて全負荷−無負荷
運転の切替指令信号を発していた。In such conventional devices, the pressure on the discharge side of the compressor is detected by a pressure switch, and a command signal for switching between full load and no load operation is issued in accordance with this detected value.
上記従来技術では、全負荷−無負荷運転の切替え指令信
号を発する圧力設定値が固定されていたため、圧縮機吐
出側の貯気槽容量にかかわらず一定の圧力値で全負荷運
転と無負荷運転を切替えていた。従って、吐出側の空気
消費量(運転負荷)が一定であれば、吐出側配管系(貯
気槽を含む)の容量が大きい程、全負荷運転−無負荷運
転の切替間隔時間(切換え周期またはオンオフ周期)が
長くなっていた。また、運転負荷が小さい場合にも、全
負荷−無負荷運転の切替え周期は長くなる。In the above conventional technology, the pressure setting value that issues the command signal for switching between full load and no load operation is fixed, so full load operation and no load operation are performed at a constant pressure value regardless of the capacity of the storage tank on the discharge side of the compressor. was switching. Therefore, if the air consumption (operating load) on the discharge side is constant, the larger the capacity of the discharge piping system (including the air storage tank), the greater the switching interval time (switching period or (on/off cycle) was getting longer. Further, even when the operating load is small, the switching cycle between full load and no load operation becomes longer.
このため、空気消費側必要圧力よりも高い吐出圧力での
圧縮機の運転時間が長くなり、不要な電力を消費すると
いう問題があった。For this reason, there is a problem in that the compressor operates for a long time at a discharge pressure higher than the required pressure on the air consumption side, and unnecessary power is consumed.
さらに、吐出側の空気使用量が多くなると、これに伴っ
て全負荷−無負荷運転の切替え周期は短くなり、頻繁に
全負荷−無負荷運転を繰り返すため装置の信頼性が低下
する問題がある。Furthermore, as the amount of air used on the discharge side increases, the switching cycle between full load and no-load operation becomes shorter, and the frequent repetition of full-load and no-load operation causes the problem of reduced reliability of the equipment. .
本発明の目的は、運転負荷(消費側ガス使用量)が小さ
い場合や吐出側配管系の容量が大きい場合での不要な高
い圧力で運転時間を低減して省エネルギ効果を向上でき
るスクリュー圧縮機の容量制御方法及び装置を得ること
にある。The purpose of the present invention is to provide a screw compressor that can improve energy saving effects by reducing operating time due to unnecessary high pressure when the operating load (gas consumption amount on the consumption side) is small or when the capacity of the discharge side piping system is large. The object of the present invention is to obtain a capacity control method and device.
本発明の他の目的は、装置の全負荷−無負荷運転の切替
え周期を一定値以上にして装置の信頼性を向上すると共
に消費側の必要圧力値を常に確保できるスクリュー圧縮
機の容量制御方法及び装置を得ることにある。Another object of the present invention is a capacity control method for a screw compressor that improves the reliability of the device by increasing the switching cycle between full load and no-load operation of the device to a certain value or more, and that can always ensure the required pressure value on the consumption side. and equipment.
上記目的を達成するための本発明の第1の特徴は、スク
リュー圧縮機の吸入側に設けたオンオフ式制御弁を圧縮
機吐出側の圧力によって制御し、全負荷運転及び無負荷
運転を実施するスクリュー圧縮機において、前記圧縮機
負荷側の圧縮ガス使用量を検出し、この使用量に応じて
、前記オンオフ制御弁をオフする上限圧力設定値または
前記オンオフ制御弁をオンする下限圧力設定値のうち少
なくとも一方を変化させ、前記オンオフ制御弁のオンオ
フ周期を予め決められた設定値以上に制御するスクリュ
ー圧縮機の容量制御方法にある。なお、圧縮機負荷側の
圧縮ガス使用量は圧縮機負荷側の圧力変化速度により求
めることともできる。The first feature of the present invention to achieve the above object is to control an on-off control valve provided on the suction side of the screw compressor by the pressure on the discharge side of the compressor to perform full-load operation and no-load operation. In a screw compressor, the amount of compressed gas used on the load side of the compressor is detected, and depending on this amount, an upper limit pressure setting value for turning off the on-off control valve or a lower limit pressure setting value for turning on the on-off control valve is set. The present invention provides a capacity control method for a screw compressor, in which at least one of the on-off control valves is changed to control the on-off period of the on-off control valve to a predetermined setting value or more. Note that the amount of compressed gas used on the compressor load side can also be determined from the pressure change rate on the compressor load side.
本発明の第2の特徴は、スクリュー圧縮機の吸入側に設
けたオンオフ式制御弁をオンオフさせて全負荷運転及び
無負荷運転を実施するスクリュー圧縮機において、前記
圧縮機負荷側の圧力を検出して、該圧力値が上限圧力設
定値に達した時前記オンオフ式制御弁をオフとして圧縮
機を無負荷運転し、前記検出した圧力値が下限圧力設定
値に達した時前記オンオフ式制御弁をオンして圧縮機を
全負荷運転すると共に、前記オンオフ式制御弁のオンオ
フ周期の長さが設定範囲になるように前記上限圧力設定
値を補正するスクリュー圧縮機の容量制御方法にある。A second feature of the present invention is that in a screw compressor that performs full load operation and no-load operation by turning on and off an on-off type control valve provided on the suction side of the screw compressor, the pressure on the load side of the compressor is detected. When the pressure value reaches the upper limit pressure set value, the on-off type control valve is turned off and the compressor is operated under no load, and when the detected pressure value reaches the lower limit pressure set value, the on-off type control valve is turned off. The present invention provides a capacity control method for a screw compressor, in which the compressor is operated at full load by turning on the on-off control valve, and the upper limit pressure set value is corrected so that the length of the on-off cycle of the on-off type control valve falls within a set range.
本発明の第3の特徴は、スクリュー圧縮機の吸入側に設
けたオンオフ式制御弁をオンオフさせて全負荷運転及び
無負荷運転を実施するスクリュー圧縮機において、前記
圧縮機負荷側の圧力を検出する圧力検出手段、前記オン
オフ式制御弁をオンオフさせるための上限圧力設定値及
び下限圧力設定値を有し、これら圧力設定値と前記圧力
検出手段からの圧力値とを比較して前記オンオフ式制御
弁をオンオフさせる制御手段、及び前記オンオフ式制御
弁のオンオフ周期が設定値以上となるように前記上限圧
力設定値または下限圧力設定値の少なくとも一方を補正
する設定値補正手段を備えているスクリュー圧縮機の容
量制御装置にある。A third feature of the present invention is that in a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off control valve provided on the suction side of the screw compressor, the pressure on the load side of the compressor is detected. pressure detection means for turning on and off the on-off type control valve, and an upper limit pressure set value and a lower limit pressure set value for turning on and off the on-off type control valve, and compares these pressure set values with the pressure value from the pressure detection means to perform the on-off type control valve. A screw compression device comprising a control means for turning on and off a valve, and a set value correction means for correcting at least one of the upper limit pressure set value or the lower limit pressure set value so that the on-off cycle of the on-off type control valve is equal to or higher than a set value. It is in the machine's capacity control device.
本発明の第4の特徴は、スクリュー圧縮機の吸入側に設
けたオンオフ式制御弁をオ゛ンオフさせて全負荷運転及
び無負荷運転を実施するスクリュー圧縮機において、前
記圧縮機負荷側の圧力を検出するため圧力検出器、前記
オンオフ式制御弁をオンオフさせるための下限圧力設定
値及び上限圧力設定値を有し、これら圧力設定値と前記
圧力検出器からの圧力値とを比較して前記オンオフ式制
御弁をオンオフ制御する制御装置、前記圧縮機負荷側の
負荷の大きさを検知する手段、及び前記負荷検知手段か
らの負荷の大きさに応じて前記上限圧力設定値または下
限圧力設定値の少なくとも一方を補正し、オンオフ式制
御弁のオンオフ周期を予め決められた設定値以上とする
設定値補正手段とを備えているスクリュー圧縮機の容量
制御装置にある。A fourth feature of the present invention is that in a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off type control valve provided on the suction side of the screw compressor, the pressure on the load side of the compressor is A pressure detector is provided to detect the on-off type control valve, and a lower limit pressure setting value and an upper limit pressure setting value are provided for turning on and off the on-off type control valve, and these pressure settings are compared with the pressure value from the pressure detector to detect the a control device for on/off controlling an on-off type control valve; a means for detecting the magnitude of the load on the compressor load side; and the upper limit pressure set value or the lower limit pressure set value depending on the magnitude of the load from the load detecting means. The present invention provides a capacity control device for a screw compressor, comprising set value correcting means for correcting at least one of the above and setting the on/off period of the on/off type control valve to be equal to or greater than a predetermined set value.
本発明の第5の特徴は、スクリュー圧縮機の吸入側に設
けたオンオフ式制御弁をオンオフさせて全負荷運転及び
無負荷運転を実施するスクリュー圧縮機において、前記
圧縮機負荷側の圧力を検出するため圧力検出器、前記オ
ンオフ式制御弁をオンオフさせるための下限圧力設定値
及び上限圧力設定値を有し、これら圧力設定値と前記圧
力検出器からの圧力値とを比較して前記オンオフ式制御
弁をオンオフ制御する制御装置、及び前記オンオフ式制
御弁のオンオフ周期の長さが設定範囲となるように前記
上限圧力設定値を補正する設定値補正手段とを備えてい
るスクリュー圧縮機の容量制御装置にある。A fifth feature of the present invention is that in a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off control valve provided on the suction side of the screw compressor, the pressure on the load side of the compressor is detected. In order to control the on-off type control valve, it has a pressure detector, a lower limit pressure set value and an upper limit pressure set value for turning on and off the on-off type control valve, and compares these pressure set values with the pressure value from the pressure detector to turn on and off the on-off type control valve. Capacity of a screw compressor comprising: a control device for controlling on/off of a control valve; and a set value correction means for correcting the upper limit pressure set value so that the length of the on/off cycle of the on/off type control valve falls within a set range. Located in the control device.
なお、上記設定値補正手段は、圧縮機負荷側の圧縮ガス
使用量(負荷の大きさ)などを検出して、これに応じて
上限圧力設定値を補正する。The set value correction means detects the amount of compressed gas used (load size) on the compressor load side, and corrects the upper limit pressure set value accordingly.
本発明の第6の特徴は、スクリュー圧縮機の吸入側に設
けたオンオフ式制御弁及びその吐出側に設けた放風弁と
を備え、圧縮機吐出側の圧力によって全負荷運転及び無
負荷運転を切替えて運転するスクリュー圧縮機において
、全負荷運転がら無負荷運転に切替える上限圧力設定値
または無負荷運転から全負荷運転に切替える下限圧力設
定値の少なくとも一方を、全負荷運転及び無負荷運転の
切替え周期が設定値以上となるように圧縮機負荷の大き
さに応じて補正する構成としたスクリュー圧縮機の容量
制御装置にある。The sixth feature of the present invention is that the screw compressor is equipped with an on-off type control valve provided on the suction side and an air blowing valve provided on the discharge side thereof, so that full load operation and no load operation are performed depending on the pressure on the compressor discharge side. In a screw compressor that operates by switching, at least one of the upper limit pressure set value for switching from full load operation to no load operation or the lower limit pressure set value for switching from no load operation to full load operation is A capacity control device for a screw compressor is configured to correct the switching period according to the magnitude of the compressor load so that it is equal to or greater than a set value.
なお、下限圧力設定値は一定とし、上限圧カ設定値だけ
を全負荷・無負荷切替え周期が設定範囲内になるように
圧縮機負荷に応じて補正するように構成すれば、最低圧
力を確保し、かつ上限圧力を必要最小限の圧力とできる
から省エネルギ効果が一層向上する。In addition, if the lower limit pressure set value is kept constant and only the upper limit pressure set value is corrected according to the compressor load so that the full load/no-load switching cycle is within the set range, the minimum pressure can be ensured. Moreover, since the upper limit pressure can be set to the minimum necessary pressure, the energy saving effect is further improved.
また、上限圧力設定値を無段階に設定していくのではな
く、上限圧力設定値を予め複数個用意し、圧縮機負荷に
応じて前記上限圧力設定値を切替えるようにしてもよい
。Further, instead of setting the upper limit pressure setting value steplessly, a plurality of upper limit pressure setting values may be prepared in advance, and the upper limit pressure setting value may be switched depending on the compressor load.
さらに、無負荷運転時の圧力降下速度を検出し、無負荷
運転から全負荷運転に切替える際に吐出側圧力が必要最
低圧力以下に低下しないように前記圧力降下速度に応じ
て下限圧力設定値を補正すれば常に必要最低圧力を確保
できる。Furthermore, the pressure drop rate during no-load operation is detected, and the lower limit pressure set value is set according to the pressure drop rate to prevent the discharge side pressure from dropping below the required minimum pressure when switching from no-load operation to full-load operation. By correcting it, you can always ensure the required minimum pressure.
本発明の第7の特徴は、スクリュー圧縮機の吸入側に設
けたオンオフ式制御弁をオンオフさせて全負荷運転及び
無負荷運転を実施するスクリュー圧縮機において、圧縮
機負荷側の圧力を検出する圧力検出器、及び前記オンオ
フ式制御弁をオンオフさせるための下限圧力設定値及び
上限圧力設定値を有し、これら圧力設定値と前記圧力検
出器からの圧力値とを比較して前記オンオフ式制御弁を
オンオフ制御すると共に、オンオフ周期が一定時間以下
とならないようにオンオフ式制御弁を制御する制御装置
を備えているスクリュー圧縮機の制御装置にある。A seventh feature of the present invention is that in a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off control valve provided on the suction side of the screw compressor, the pressure on the load side of the compressor is detected. It has a pressure detector, and a lower limit pressure set value and an upper limit pressure set value for turning on and off the on-off type control valve, and compares these pressure set values with the pressure value from the pressure detector to perform the on-off type control. A control device for a screw compressor includes a control device that controls the on-off type control valve so that the on-off cycle does not become shorter than a certain period of time.
本発明の第8の特徴は、スクリュー圧縮機の吸入側に設
けたオンオフ式制御弁及びその吐出側に設けた放風弁と
を備え、圧縮機吐出側の圧力によって全負荷運転及び無
負荷運転を切替えて運転するスクリュー圧縮機において
、無負荷運転から全負荷運転に切替えるための下限圧力
で作動する低圧側圧力スイッチ、全負荷運転から無負荷
運転に切替えるための上限圧力で作動する複数個の設定
圧力の異なる高圧側圧力スイッチ、及び、前記複数個の
高圧側圧力スイッチのうち設定圧力の低い方の圧力スイ
ッチが作動後の時間を計測するタイマーを備え、前記複
数個の高圧側圧力スイッチとタイマーとにより全負荷運
転と無負荷運転の切替え後一定時間は設定圧力の高い方
の圧力スイッチが作動するまでは全負荷・無負荷の運転
切替えを停止させるように構成したスクリュー圧縮機の
容量制御装置にある。The eighth feature of the present invention is that the screw compressor is equipped with an on-off type control valve provided on the suction side and an air blowing valve provided on the discharge side thereof, so that full load operation and no load operation are performed depending on the pressure on the compressor discharge side. In a screw compressor that operates by switching between High-pressure side pressure switches having different set pressures, and a timer for measuring the time after the pressure switch with a lower set pressure among the plurality of high-pressure side pressure switches is activated, and the plurality of high-pressure side pressure switches and Capacity control of a screw compressor configured to use a timer to stop switching between full load and no load operation for a certain period of time after switching between full load and no load operation until the pressure switch with the higher set pressure is activated. It's in the device.
上記構成とすることにより、オンオフ式制御弁をオン状
態とし、圧縮機が全負荷運転されると、吐出側圧力が上
昇し、上限圧力設定値に達すると、オンオフ制御弁はオ
フ状態とされ圧縮機は全負荷運転から無負荷運転へ切替
わる。負荷側のガス使用量に応じて吐出側圧力は低下し
、下限圧力設定値に達すると圧縮機は無負荷運転から全
負荷運転に切替わり、吐出側圧力は再び上昇していく。With the above configuration, when the on-off type control valve is turned on and the compressor is operated at full load, the discharge side pressure increases and when it reaches the upper limit pressure set value, the on-off control valve is turned off and the compressor is operated at full load. The machine switches from full load operation to no load operation. The pressure on the discharge side decreases according to the amount of gas used on the load side, and when the lower limit pressure setting is reached, the compressor switches from no-load operation to full-load operation, and the pressure on the discharge side increases again.
以下同様に繰返す。Repeat the same below.
本発明では、負荷の大きさ、即ち消費側の圧縮ガス使用
量を、全負荷運転時の圧力上昇速度または無負荷運転時
の圧力降下速度などを検出して求め、この負荷の大きさ
に応じてオンオフ式制御弁をオンオフする下限圧力設定
値または上限圧力設定値を補正するようにしているから
、全負荷−無負荷運転の切替え周期を予め決められた一
定値以上に制御することができ、装置の信頼性を向上で
きると共に、消費側の必要圧力値を下限値として設定す
ることにより、必要圧力を常時確保できる。In the present invention, the magnitude of the load, that is, the amount of compressed gas used on the consumption side, is determined by detecting the rate of pressure increase during full load operation or the rate of pressure decrease during no load operation, and is determined according to the magnitude of the load. Since the lower limit pressure set value or upper limit pressure set value for turning on and off the on-off type control valve is corrected, the switching cycle between full load and no load operation can be controlled to a predetermined constant value or higher. The reliability of the device can be improved, and by setting the required pressure value on the consumption side as a lower limit value, the required pressure can be ensured at all times.
この下限圧力設定値を、無負荷運転時の圧力降下速度を
検出して、これを考慮して設定することにより、無負荷
運転から全負荷運転に切替わる際の吐出側圧力が必要最
低圧力以下に低下するのを確実に防止できる。By detecting the pressure drop rate during no-load operation and setting this lower limit pressure setting value in consideration of this, the discharge side pressure when switching from no-load operation to full-load operation is below the required minimum pressure. It is possible to reliably prevent this from dropping.
また、オンオフ式制御弁のオンオフ周期の長さが設定範
囲となるように、上限圧力設定値を圧縮機負荷の大きさ
に応じて補正することにより、運転負荷がホさい場合や
吐出側配管系の容量が大きい場合には上限圧力設定値が
低くなるので、不要な高い圧力での運転時間を低減する
ことができ、省エネルギ効果を向上することができる。In addition, by correcting the upper limit pressure set value according to the size of the compressor load so that the length of the on-off cycle of the on-off type control valve is within the set range, it is possible to When the capacity of the pump is large, the upper limit pressure setting value becomes lower, so the operating time at unnecessary high pressure can be reduced, and the energy saving effect can be improved.
以下1本発明のスクリュー圧縮機の容量制御装置の一実
施例を第1図により説明する0図はスクリュー圧縮機の
空気系統と容量制御装置のフローを示したものである。An embodiment of the capacity control device for a screw compressor according to the present invention will be explained below with reference to FIG. 1. FIG. 0 shows the flow of the air system of the screw compressor and the capacity control device.
スクリュー圧縮機全負荷運転状態では、吸入口14から
吸入した空気は吸入フィルター19を通り、全閉状態の
吸入弁(オンオフ式制御弁)2を通り圧縮機本体1へ入
る。圧縮機本体で圧縮された高温高圧の空気は逆止弁1
3、アフタークーラ12を通って貯気槽11へ送り込ま
れる。貯気槽11内に貯められた空気は、空気消費ライ
ン16へ送られ消費される。尚、この状態では放風弁3
は閉じている。また、吸入弁2と放風弁3を駆動してい
る油圧ピストン4は、四方電磁弁5と油圧ポンプ6によ
って貯油槽7から供給された油によって吸入弁2を開、
放風弁3を閉にする位置に押されている。When the screw compressor is operating at full load, air sucked in from the suction port 14 passes through the suction filter 19, passes through the suction valve (on-off control valve) 2 in a fully closed state, and enters the compressor body 1. The high-temperature, high-pressure air compressed by the compressor body passes through check valve 1.
3. The air is sent to the air storage tank 11 through the aftercooler 12. The air stored in the air storage tank 11 is sent to the air consumption line 16 and consumed. In addition, in this state, the air discharge valve 3
is closed. In addition, the hydraulic piston 4 that drives the suction valve 2 and the air discharge valve 3 opens the suction valve 2 with oil supplied from the oil storage tank 7 by the four-way solenoid valve 5 and the hydraulic pump 6.
The blow-off valve 3 is pushed to the closed position.
一般に全負荷運転時は、′/S費空気量よりも圧縮機吐
出量の方が多く、吐出側圧力は上昇していく。Generally, during full load operation, the compressor discharge amount is greater than the '/S cost air amount, and the discharge side pressure increases.
この吐出側圧力を圧力センサ8で検出し、制御装置9へ
送る。制御装置9では検出された吐出側圧力Pが予め設
定されている上限(圧力設定)値Pmaxに達すると、
四方電磁弁5に指令を発して四方電磁弁5の油通路を切
替え油圧ピストン4を作動させて、吸入弁2を閉にし、
同時に放風弁3を開にして圧縮機1を無負荷運転状態に
する。吸入弁2から圧縮機1へ洩れ込んだ空気は、圧縮
機1から出た後放風弁3を通り放風サイレンサ1゜を通
って放風口15から大気に放風される。This discharge side pressure is detected by a pressure sensor 8 and sent to a control device 9. In the control device 9, when the detected discharge side pressure P reaches a preset upper limit (pressure setting) value Pmax,
A command is issued to the four-way solenoid valve 5 to switch the oil passage of the four-way solenoid valve 5, operate the hydraulic piston 4, and close the intake valve 2.
At the same time, the blowoff valve 3 is opened to put the compressor 1 into a no-load operating state. Air leaking into the compressor 1 from the suction valve 2 exits the compressor 1, passes through the blow-off valve 3, passes through the blow-off silencer 1°, and is blown into the atmosphere from the blow-off port 15.
無負荷運転状態では圧縮機本体1から貯気槽11へ空気
は供給されず、貯気槽11内の空気は消費されていくか
ら貯気槽11を含む吐出側配管系の圧力(以下吐出側圧
力という)Pが低下していき、予め設定しである下限設
定圧力P winまで圧力が低下すると制御装置9によ
り四方電磁弁5を切替えて再度全負荷運転状態にする構
成となっている。In the no-load operating state, air is not supplied from the compressor main body 1 to the air storage tank 11, and the air in the air storage tank 11 is consumed. P (referred to as pressure) decreases, and when the pressure decreases to a preset lower limit pressure P win, the control device 9 switches the four-way solenoid valve 5 to return to the full load operating state.
制御装置9は、圧力検出部、記憶部、計時部。The control device 9 includes a pressure detection section, a storage section, and a time measurement section.
演算部などを内蔵しており、吐出側圧力を検出し。It has a built-in calculation section and detects the discharge side pressure.
全負荷運転時間Δt工と無負荷運転時間Δt2の切替間
隔時間(切替え周期Δt1+Δtz)Δtを計時し、Δ
Pをこの切替え周期Δtが設定範囲(Δtmln〜Δt
wax)内になるように、上限圧力設定値P +aa
Xと下限圧力設定値P□、との圧力差ΔPを演算し、P
maXI P mlnの少なくとも一方を補正し、検
出された圧力値Pと比較して四方電磁弁5の切替信号を
発する。Δt工、Δt2の計時はある一定時間繰り返し
て行い、数サイクルの平均値を求め、その平均的な切替
え周期Δtと予め設定されたΔt□。とを比較し、Δt
−+n<ΔtくΔj +maxの条件を満たさなければ
、これを満たすようにΔPを補正していく。Measure the switching interval time (switching period Δt1 + Δtz) Δt between the full load operating time Δt and the no-load operating time Δt2, and calculate Δt.
The switching period Δt of P is within the setting range (Δtmln~Δt
wax), set the upper limit pressure setting value P +aa
Calculate the pressure difference ΔP between X and the lower limit pressure setting value P□, and
At least one of maXI P mln is corrected and compared with the detected pressure value P to issue a switching signal for the four-way solenoid valve 5. The timing of Δt and Δt2 is repeated for a certain period of time, the average value of several cycles is determined, and the average switching period Δt and the preset Δt□ are determined. Δt
If the condition -+n<Δt Δj +max is not satisfied, ΔP is corrected so as to satisfy this condition.
制御装置9の演算部の処理フローの例を第2図に示す。An example of the processing flow of the arithmetic unit of the control device 9 is shown in FIG.
まず最初に、下限圧力設定値P□。。First of all, lower limit pressure setting value P□. .
ΔP初期値設定(p、i、+ΔP = P−ax・・・
上限圧力設定値)、及び切替え周期の最小値Δt□、を
設定しておく(ステップ20)。次に、実際の切替え周
期Δtを測定する(ステップ21)。更に、ステップ2
3で、ΔtをΔtlllnと比較し、Δt=Δjmtn
なら、24aに示すように設定されているΔPをそのま
ま補正後のΔP′として使用し、補正データAとしてス
テップ20における設定値を補正していく。また、ステ
ップ23で、ΔtくΔt+w。あるいはΔt〉Δt□、
の場合にはΔtが大きな値あるいは小さな値となるよう
にΔPを補正する必要があるが、本実施例では、24b
。ΔP initial value setting (p, i, +ΔP = P-ax...
(upper limit pressure setting value) and the minimum value Δt□ of the switching cycle are set (step 20). Next, the actual switching period Δt is measured (step 21). Furthermore, step 2
3, compare Δt with Δtllln, Δt=Δjmtn
If so, the ΔP set as shown in 24a is used as it is as the corrected ΔP', and the set value in step 20 is corrected as the correction data A. Further, in step 23, Δt Δt+w. Or Δt〉Δt□,
In this case, it is necessary to correct ΔP so that Δt becomes a large value or a small value, but in this example, 24b
.
24cに示すように、補正後の圧力差ΔP′をとして与
え、これを補正データAとして、ステップ20における
設定値ΔPを補正する。As shown in 24c, the pressure difference ΔP' after correction is given as correction data A, and the set value ΔP in step 20 is corrected.
本実施例によれば、P sinとPmaxの圧力差へP
が必要最小値になるように制御されるから吐出側圧力の
変動幅を最小にすることができる。According to this embodiment, P
Since the pressure is controlled to be the required minimum value, the fluctuation width of the discharge side pressure can be minimized.
第3図は、上記実施例において、下限圧力設定値P w
inを固定し、上限圧力設定値P waxのみを補正デ
ータAに基づいて変化させる様にした場合の実施例にお
ける吐出側圧力変化と動力の変化を示した線図である。FIG. 3 shows the lower limit pressure setting value P w in the above embodiment.
FIG. 4 is a diagram showing a change in discharge side pressure and a change in power in an example in which in is fixed and only the upper limit pressure set value P wax is changed based on correction data A. FIG.
図中aの場合について説明すると、スクリュー圧縮機が
全負荷運転状態で圧縮機から供給される空気量が、消費
空気量より多いため吐出側圧力が上昇した上限圧力設定
値P□8に達すると、スクリュー圧縮機は全負荷運転か
ら無負荷運転へと切替わる。無負荷運転状態であるスク
リュー圧縮機からの空気の供給がなく、貯気槽内空気を
消費するに従って吐出側圧力は低下する。吐出側圧力が
圧力下限圧力設定値P m l nまで低下すると圧縮
機は無負荷運転から全負荷運転へ切替わり、吐出側圧力
が上昇する。以後同様の動作を繰り返す。設定圧力値の
上限値P+mayと下限値P0゜の差圧をΔPとし、圧
縮機風量Qに対する消費空気量の比をqとすると、全負
荷運転時の吐出側圧力がP winからPmaxまで上
昇するのに要する時間Δも□及び無負荷運転時に吐出側
圧力がP m&XからP m1nまで低下するのに要す
る時間Δt2は次式で表わされる。To explain case a in the figure, when the screw compressor is operating at full load and the amount of air supplied from the compressor is greater than the amount of air consumed, when the discharge side pressure reaches the upper limit pressure set value P□8. , the screw compressor switches from full load operation to no load operation. There is no supply of air from the screw compressor, which is in a no-load operating state, and as the air in the storage tank is consumed, the discharge side pressure decreases. When the discharge side pressure decreases to the pressure lower limit pressure set value P m l n, the compressor switches from no-load operation to full-load operation, and the discharge side pressure increases. The same operation is repeated thereafter. If the differential pressure between the upper limit P+may and the lower limit P0° of the set pressure value is ΔP, and the ratio of the consumed air volume to the compressor air volume Q is q, the discharge side pressure during full load operation increases from P win to P max. The time Δ required for this and the time Δt2 required for the discharge side pressure to decrease from P m&X to P m1n during no-load operation are expressed by the following equation.
Δt=Δt1+Δt2
q(1q)PsQs
上式より空気消費率qが一定ならば、ΔPを小さくする
ことによってΔtは短くなる。一方、Δtは一般に容量
制御装置の機械的制限よりある値以上にする必要がある
。八tの最小値をΔjmin とし、その時のΔPをΔ
P m I nとすると、■
となる。いま、実稼動状態で、あるΔPにおけるΔtを
測定すれば、Δj manとなる圧力差ΔP m t
nは
Δt
で求めることができる。Δt=Δt1+Δt2 q(1q)PsQs According to the above equation, if the air consumption rate q is constant, Δt becomes shorter by decreasing ΔP. On the other hand, Δt generally needs to be greater than a certain value due to mechanical limitations of the capacity control device. The minimum value of 8t is Δjmin, and ΔP at that time is Δ
When P m I n, it becomes ■. Now, if we measure Δt at a certain ΔP in the actual operating state, the pressure difference ΔP m t becomes Δj man
n can be determined by Δt.
圧縮機風量に比べて十分な貯気槽容積がある場合は、Δ
tは余裕があるため、Δt、、nまでΔtを短くするこ
とによって吐出側圧力の変動幅を小さく抑えることがで
きる。If the storage tank volume is sufficient compared to the compressor air volume, Δ
Since t has a margin, by shortening Δt to Δt, .
第2図中すは、aに対して最低圧力P mln を固定
してΔPをΔP′へと小さくした場合の吐出側圧力変化
と、動力を示したものである。aとbの平均動力を比較
すると、次の様し;なる。The box in FIG. 2 shows the change in pressure on the discharge side and the power when the lowest pressure P mln is fixed with respect to a and ΔP is reduced to ΔP'. Comparing the average power of a and b, it is as follows;
aの平均動力Lave
2 Δt Δt
・・・(7)
bの平均動力L’ave
・・・(8)
一方、式(2) (3) (4)より明らかな様に、Δ
t Δ t
であり、a、bにおいて空気消費率qが一定であるとす
れば、
Lave L’ ave” (Lmax L’
wax) X q・・・(10)
となり、L 11aX>L’+maXであるからbはa
よりも平均動力が小さくなる。Average power of a Lave 2 Δt Δt (7) Average power of b L'ave (8) On the other hand, as is clear from equations (2), (3), and (4), Δ
t Δ t and the air consumption rate q is constant at a and b, then Lave L'ave" (Lmax L'
wax) X q...(10) Since L 11aX>L'+maX, b is
The average power is smaller than that.
また、空気消費率qが安定した状態でΔt工。Also, when the air consumption rate q is stable, Δt is applied.
Δt2を測定すれば、(4)式、(9)式より、圧縮機
Kを一旦求めると、全負荷運転時又は無負荷運転時の圧
力変化速度d P/d t、(又はd P/d t、)
を測定することにより、ΔP 1llIn を次式で求
めることができる。If Δt2 is measured, once the compressor K is determined from equations (4) and (9), the rate of pressure change during full load operation or no load operation d P/d t, (or d P/d t,)
By measuring ΔP 1llIn , it is possible to obtain ΔP 1llIn using the following equation.
・・・(11)
又は、
・・・(11’)
によれば、貯気槽容積が大きい場合や圧縮機負荷が小さ
い場合、P waxがP’maXで示すように小さく設
定されるから不必要な高圧で圧縮機が駆動されず動力の
低減が可能となる。According to ...(11) or ...(11'), when the storage tank volume is large or the compressor load is small, P wax is set small as shown by P'maX, so there is no problem. The compressor is not driven at the required high pressure, making it possible to reduce power.
また第3図中に示した様に、Δt□、Δt2は運転開始
時の初期状態でのみ計時し、その後は圧力変化速度dP
、/d tlを測定してΔP、I□を算呂すれば、空気
消費率が刻々変化する場合でも常に最適な設定値ΔPを
設定することが可能である。Also, as shown in Figure 3, Δt□ and Δt2 are measured only in the initial state at the start of operation, and thereafter the pressure change rate dP
, /d tl and calculate ΔP and I□, it is possible to always set the optimal setting value ΔP even when the air consumption rate changes every moment.
第4図は、吐出側圧力の圧力降下速度d P、/dto
が大きい場合、無負荷から全負荷に切替わるための時間
が必要であるために、下限圧力設定値Pan1□を大き
く越えて吐出側圧力Pが曲1iAcで示すように低下す
る場合があるので、吐出側圧力Pが下限圧力設定値P0
゜以下になるのを防止するようにした実施例である。本
実施例では予め、圧力降下速度d P、/d toと下
限圧力設定値P 111 n を越えて低下する超過圧
力ΔPc との関係を測定しておき、運転中のdPo/
dt、を検知して吐出側圧力がP□。以下に下がらない
ように。Figure 4 shows the pressure drop rate dP,/dto of the discharge side pressure.
If is large, time is required to switch from no load to full load, so the discharge side pressure P may drop far beyond the lower limit pressure setting value Pan1□ as shown in curve 1iAc. The discharge side pressure P is the lower limit pressure setting value P0
This is an example in which the temperature is prevented from falling below . In this example, the relationship between the pressure drop rate dP,/dto and the overpressure ΔPc that decreases beyond the lower limit pressure set value P111n is measured in advance, and dPo/dto during operation is measured.
dt, and the discharge side pressure becomes P□. Don't go below.
下限圧力設定値をPo。がらP。に上げる様に制御する
ので、圧力が最低圧力P 1lln以下に下がることが
ない。Set the lower limit pressure setting value to Po. GaraP. Since the pressure is controlled so as to be raised to 1, the pressure does not fall below the minimum pressure P1lln.
更に詳しく説明する。曲線Cの場合、吐出側圧力がP
l1lnに達したA点で容量調整装置に信号を発し、無
負荷運転から全負荷運転へ切替わるが。It will be explained in more detail. In the case of curve C, the discharge side pressure is P
At point A when l1ln is reached, a signal is sent to the capacity adjustment device and the no-load operation is switched to full-load operation.
容量調整装置の(オンオフ式制御弁及び放風弁など)の
作動時間があるため、吐出側圧力はPl、1を越えてΔ
Pcだけの圧力弁低下する。これに対して、まず最初に
圧力降下速度dPa/d t、とΔPC0を測定してお
き、下限圧力設定値をdP/dtに従ってP□。からP
oへ上げれば、B点で容量調整装置が作動しはじめるた
め、吐出側圧力がP mln以下に低下することがない
。この場合のpoは次式で求める。Due to the operating time of the capacity adjustment device (on/off type control valve, blow-off valve, etc.), the discharge side pressure exceeds Pl, 1 and becomes Δ.
The pressure valve of Pc only decreases. On the other hand, first measure the pressure drop rate dPa/dt and ΔPC0, and set the lower limit pressure setting value P□ according to dP/dt. From P
If the pressure is increased to 0, the capacity adjustment device starts operating at point B, so the discharge side pressure will not drop below Pmln. po in this case is determined by the following formula.
P clt。P clt.
第5図は第1図に示した制御装置9の具体例を示すブロ
ック図である。圧力センサ8により検出された圧力信号
は、A/D変換器91にてアナログ信号からデジタル信
号に変換され、中央演算処理袋w92へ送られる。中央
演算処理装置(92内には計時回路を有し、圧力信号と
計時信号により比較、演算処理をし、容量調節弁のオン
・オフ信号を出力する。また、回路にはΔjmtn+
Pm1n+P、&×などの設定値を記憶するリードオン
リーメモリ(ROM)93と、演算結果などを一時的に
記憶するランダムアクセスメモリ(RAM)、94を有
する。FIG. 5 is a block diagram showing a specific example of the control device 9 shown in FIG. 1. The pressure signal detected by the pressure sensor 8 is converted from an analog signal to a digital signal by an A/D converter 91, and sent to the central processing module w92. The central processing unit (92 has a clock circuit, which performs comparison and arithmetic processing based on the pressure signal and the clock signal, and outputs an on/off signal for the capacity control valve. Also, the circuit has a Δjmtn+
It has a read-only memory (ROM) 93 that stores setting values such as Pm1n+P and &×, and a random access memory (RAM) 94 that temporarily stores calculation results and the like.
第6図は第1図の制御装!9として、計時部を有し上限
圧力設定値p waxを2種類(PwraxxrP m
aX2 )設定できる圧力スイッチを使用した場合のフ
ローを示す図である。Figure 6 is the control system shown in Figure 1! 9, it has a timer section and has two types of upper limit pressure setting values p wax (P wraxxrP m
aX2) is a diagram showing the flow when using a pressure switch that can be set.
まず、ステップ30で、P waxlp P maX2
1Δt1□。を予め設定しておく。ステップ31では圧
縮機の全負荷運転を開始すると共に吐出側圧力Pを測定
を開始し、同時にΔtを計測する。ステップ32では、
計測されたPと小さい方の上限圧力設定値Pmax□を
比較し、P≧Pox□の条件を満たすまで、繰り返す。First, in step 30, P waxlp P maX2
1Δt1□. Set in advance. In step 31, full load operation of the compressor is started, and at the same time measurement of the discharge side pressure P is started, and Δt is measured at the same time. In step 32,
The measured P is compared with the smaller upper limit pressure setting value Pmax□, and the process is repeated until the condition of P≧Pox□ is satisfied.
P≧Pヨa2□となったとき。When P≧Pyoa2□.
ステップ33へ進み、上記Δtと最小限の切替え時間Δ
tlllinと比較し、最小切替え時間Δt1□□より
もΔtが小さい場合は負荷が小さいということであるか
らステップ35へ進み、無負荷運転に切替える。Δtが
Δt1m1nよりも大きい場合は負荷大であるからステ
ップ34へ進み前記検出圧力値Pが大きい方の上限圧力
設定値P maXzよりも大きくなるまでは全負荷運転
を続け、P≧Pmaxzとなった時ステップ35へ進み
無負荷運転に切替えられる。設定値Δt工□。は、オン
オフ式制御弁2や放風弁3を作動させるための時間など
の機械的制約及びオンオフ切替えによる制御弁や電磁弁
などの機械寿命などを考慮して決める。Proceeding to step 33, the above Δt and the minimum switching time Δ
tlllin, and if Δt is smaller than the minimum switching time Δt1□□, it means that the load is small, so the process proceeds to step 35 and switches to no-load operation. If Δt is larger than Δt1m1n, the load is large, so the process proceeds to step 34, and full-load operation is continued until the detected pressure value P becomes larger than the larger upper limit pressure set value PmaXz, so that P≧Pmaxz. The process then proceeds to step 35 and is switched to no-load operation. Set value Δt engineering □. is determined in consideration of mechanical constraints such as the time required to operate the on-off type control valve 2 and the blow-off valve 3, and the mechanical life of the control valve and solenoid valve due to on/off switching.
第7図は、上記第6図に示す実施例を実現するための制
御装置の電気回路図である。40は検出圧力値PがP
+11111より小さい場合にONL、P maxtで
OFFする圧力スイッチ、41はPがP mlnより小
でONし、Pmax□より大でOFFする圧力スイッチ
、42はスイッチPIXを0N−OFFするリレー、4
3はスインP2Xを○N−0FFするリレー、44はス
イッチ46Xを0N−OFFするリレー、45はスイッ
チ46XがONすると時間計測を開始するタイマーであ
り、ある設定時間ti□。に達したとき、スイッチTを
ONするものである。このような電気回路構成とするこ
とにより、圧縮機を作動させると、リレー42.43に
よりスイッチPIX、PIXがONし、リレー46Xを
介して、スイッチ46XがONする。したがって、全負
荷運転が開始すると共に、タイし−45が経過時間Δt
よを計測する。負荷が大きいためにPがPmax□に達
する前にΔt工がt工lli。FIG. 7 is an electrical circuit diagram of a control device for realizing the embodiment shown in FIG. 6 above. 40 means that the detected pressure value P is P
41 is a pressure switch that turns ON when P is smaller than P mln and turns OFF when P is larger than Pmax□; 42 is a relay that turns switch PIX ON-OFF; 4
3 is a relay that turns the switch P2X ON-OFF, 44 is a relay that turns ON-OFF the switch 46X, and 45 is a timer that starts measuring time when the switch 46X is turned ON, and a certain set time ti□. When this is reached, the switch T is turned on. With such an electric circuit configuration, when the compressor is operated, switches PIX and PIX are turned on by relays 42 and 43, and switch 46X is turned on via relay 46X. Therefore, at the same time as full load operation starts, the tie -45 is increased by the elapsed time Δt
Measure yo. Because the load is large, Δt will exceed t before P reaches Pmax□.
に達するとスイッチTが閉じられるから、P〉wax□
の条件を満たしスイッチPIXがOFFとなってもP
> P−ax□となるまでは全負荷運転を継続する。負
荷が小さい場合にはP>P−a−□の条件が全負荷運転
開始後すぐに満たされる。このためt□くΔt工1nの
間はスイッチTがONされていないから、P > P
、、、□の条件でスイッチPIXがOFFされると同時
にスイッチ46XがOFFされ、急負荷運転となる。When it reaches, switch T is closed, so P〉wax□
Even if the conditions are met and switch PIX is turned off, P
> Continue full load operation until P-ax□. When the load is small, the condition P>P-a-□ is satisfied immediately after the start of full-load operation. Therefore, since the switch T is not turned on during t□ and Δt and 1n, P > P
When the switch PIX is turned off under the conditions of , , □, the switch 46X is turned off at the same time, resulting in sudden load operation.
このような構成とすることにより、複数の圧力スイッチ
と簡単な電気回路だけでオンオフ式制御弁を制御する制
御装置を構成することができ、安価に省エネルギ効果を
向上でき、かつ全負荷−無負荷の切替え周期を一定値以
上とした装置を実現できる。With this configuration, it is possible to configure a control device that controls an on-off type control valve using only multiple pressure switches and a simple electric circuit, and it is possible to improve the energy saving effect at low cost, and also to reduce the total load to no load. It is possible to realize a device in which the load switching cycle is greater than or equal to a certain value.
本発明によれば、消費側の圧縮ガス使用量、即ち負荷の
大きに応じて、圧縮機吸入側に設けたオンオフ式制御弁
をオンオフするため下限圧力設定値または上限圧力設定
値を補正するようにしているから、圧縮機の全負荷−無
負荷運転の切替え周期をある一定値以上とすることがで
き、負荷が大きくなった場合でも頻繁な運転切替えを防
止でき、装置の信頼性を向上できる。According to the present invention, the lower limit pressure set value or the upper limit pressure set value is corrected in order to turn on and off the on-off type control valve provided on the compressor suction side according to the amount of compressed gas used on the consumption side, that is, the size of the load. Because of this, the switching cycle between full load and no load operation of the compressor can be kept above a certain value, preventing frequent operation switching even when the load is large, and improving the reliability of the equipment. .
また、消費側の最低必要圧力を下限値として設定すれば
、必要圧力を常時確保することができる。Further, by setting the minimum required pressure on the consumption side as the lower limit value, the required pressure can be ensured at all times.
さらに、オンオフ式制御弁のオンオフ周期の長さが設定
範囲となるように、上限圧力設定値を圧縮機負荷の大き
さに応じて補正することにより、運転負荷が小さい場合
や吐出側配管系の容量が大きい場合には上限圧力設定値
が低くなるので、不要な高い圧力での圧縮機運転時間を
低減でき、省エネルギ効果を向上することができる。Furthermore, by correcting the upper limit pressure set value according to the size of the compressor load so that the length of the on-off cycle of the on-off type control valve is within the set range, it is possible to When the capacity is large, the upper limit pressure setting value becomes lower, so the compressor operation time at unnecessary high pressure can be reduced, and the energy saving effect can be improved.
第1図は本発明の一実施例を示す全体構成図、第2図は
第1図に示す制御装置の演算処理フローの例を示すフロ
ーチャート、第3図は本発明の実施例における吐出側圧
力変化と動力の変化を示す線図、第4図は無負荷運転か
ら全負荷運転に切替わる際の吐出側圧力の変化を説明す
る線図、第5図は第1図に示した制御装置の具体例を示
すブロック図、第6図は第1図の制御装置として計時部
を有し上限圧力設定値を2種類設定できる圧力スイッチ
を使用した場合の処理のフローチャート、第7図は第6
図に示す実施例を実現するための制御装置の電気回路図
である。
1・・・圧縮機本体、2・・・吸入弁オンオフ式制御弁
、3・・・放風弁、4・・・ピストン、5・・・四方電
磁弁、6・・油ポンプ、8・・・圧力センサ(圧力検出
器)、9・・制御装置、11・・・貯気槽。
先3日
も牛図
為5日
光6(3)Fig. 1 is an overall configuration diagram showing an embodiment of the present invention, Fig. 2 is a flowchart showing an example of the calculation processing flow of the control device shown in Fig. 1, and Fig. 3 is a discharge side pressure in an embodiment of the present invention. Figure 4 is a diagram showing the change in discharge side pressure when switching from no-load operation to full-load operation, and Figure 5 is a diagram showing the change in the control device shown in Figure 1. A block diagram showing a specific example, FIG. 6 is a flowchart of the process when a pressure switch having a timer unit and capable of setting two types of upper limit pressure set values is used as the control device in FIG. 1, and FIG.
FIG. 3 is an electrical circuit diagram of a control device for realizing the embodiment shown in the figure. DESCRIPTION OF SYMBOLS 1...Compressor body, 2...Suction valve on/off type control valve, 3...Blowout valve, 4...Piston, 5...Four-way solenoid valve, 6...Oil pump, 8... -Pressure sensor (pressure detector), 9...control device, 11...air storage tank. The last 3 days were also a cow act 5 Nikko 6 (3)
Claims (1)
弁を圧縮機吐出側の圧力によつて制御し、全負荷運転及
び無負荷運転を実施するスクリュー圧縮機において、前
記圧縮機負荷側の圧縮ガス使用量を検出し、この使用量
に応じて、前記オンオフ制御弁をオフする上限圧力設定
値または前記オンオフ制御弁をオンする下限圧力設定値
のうち少なくとも一方を変化させ、前記オンオフ制御弁
のオンオフ周期を予め決められた設定値以上に制御する
ことを特徴とするスクリュー圧縮機の容量制御方法。 2、請求項1において、圧縮機負荷側の圧縮ガス使用量
を圧縮機負荷側の圧力変化速度により求めることを特徴
とするスクリュー圧縮機の容量制御方法。 3、スクリュー圧縮機の吸入側に設けたオンオフ式制御
弁をオンオフさせて全負荷運転及び無負荷運転を実施す
るスクリュー圧縮機において、前記圧縮機負荷側の圧力
を検出して、該圧力値が上限圧力設定値に達した時前記
オンオフ式制御弁をオフとして圧縮機を無負荷運転し、
前記検出した圧力値が下限圧力設定値に達した時前記オ
ンオフ式制御弁をオンして圧縮機を全負荷運転すると共
に、前記オンオフ式制御弁のオンオフ周期の長さが設定
範囲になるように前記上限圧力設定値を補正することを
特徴とするスクリュー圧縮機の容量制御方法。 4、請求項3において、オンオフ制御弁のオンオフ周期
の長さが一定となるように上限圧力設定値を補正してい
くことを特徴とするスクリュー圧縮機の容量制御方法。 5、スクリュー圧縮機の吸入側に設けたオンオフ式制御
弁をオンオフさせて全負荷運転及び無負荷運転を実施す
るスクリュー圧縮機において、前記圧縮機負荷側の圧力
を検出する圧力検出手段、前記オンオフ式制御弁をオン
オフさせるための上限圧力設定値及び下限圧力設定値を
有し、これら圧力設定値と前記圧力検出手段からの圧力
値とを比較して前記オンオフ式制御弁をオンオフさせる
制御手段、及び前記オンオフ式制御弁のオンオフ周期が
設定値以上となるように前記上限圧力設定値または下限
圧力設定値の少なくとも一方を補正する設定値補正手段
を備えていることを特徴とするスクリュー圧縮機の容量
制御装置。6、スクリュー圧縮機の吸入側に設けたオン
オフ式制御弁をオンオフさせて全負荷運転及び無負荷運
転を実施するスクリュー圧縮機において、前記圧縮機負
荷側の圧力を検出するため圧力検出器、前記オンオフ式
制御弁をオンオフさせるための下限圧力設定値及び上限
圧力設定値を有し、これら圧力設定値と前記圧力検出器
からの圧力値とを比較して前記オンオフ式制御弁をオン
オフ制御する制御装置、前記圧縮機負荷側の負荷の大き
さを検知する手段、及び前記負荷検知手段からの負荷の
大きさに応じて前記上限圧力設定値または下限圧力設定
値の少なくとも一方を補正し、オンオフ式制御弁のオン
オフ周期を予め決められた設定値以上とする設定値補正
手段とを備えていることを特徴とするスクリュー圧縮機
の容量制御装置。 7、スクリュー圧縮機の吸入側に設けたオンオフ式制御
弁をオンオフさせて全負荷運転及び無負荷運転を実施す
るスクリュー圧縮機において、前記圧縮機負荷側の圧力
を検出するため圧力検出器、 前記オンオフ式制御弁をオンオフさせるための下限圧力
設定値及び上限圧力設定値を有し。 これら圧力設定値と前記圧力検出器からの圧力値とを比
較して前記オンオフ式制御弁をオンオフ制御する制御装
置、及び 前記オンオフ式制御弁のオンオフ周期の長さが設定範囲
となるように前記上限圧力設定値を補正する設定値補正
手段、 とを備えていることを特徴とするスクリュー圧縮機の容
量制御装置。 8、請求項7において、前記設定値補正手段は、圧縮機
負荷側の圧縮ガス使用量(負荷の大きさ)に応じて前記
上限圧力設定値を補正することを特徴とするスクリュー
圧縮機の容量制御装置。 9、請求項8において、圧縮機負荷側の圧縮ガス使用量
を圧縮機負荷側の圧力変化速度により求めることを特徴
とするスクリュー圧縮機の容量制御装置。 10、スクリュー圧縮機の吸入側に設けたオンオフ式制
御弁及びその吐出側に設けた放風弁とを備え、圧縮機吐
出側の圧力によつて全負荷運転及び無負荷運転を切替え
て運転するスクリュー圧縮機において、全負荷運転から
無負荷運転に切替える上限圧力設定値または無負荷運転
から全負荷運転に切替える下限圧力設定値の少なくとも
一方を、全負荷運転及び無負荷運転の切替え周期が設定
値以上となるように圧縮機負荷の大きさに応じて補正す
る構成としたこと特徴とするスクリュー圧縮機の容量制
御装置。 11、請求項10において、下限圧力設定値は一定とし
、上限圧力設定値だけを全負荷・無負荷切替え周期が設
定範囲内になるように圧縮機負荷に応じて補正すること
を特徴とするスクリュー圧縮機の容量制御装置。 12、請求項10または11において、圧縮機負荷を、
全負荷運転時または無負荷運転時の少なくとも一方にお
ける圧縮機吐出側圧力の変化速度を検知して求めること
を特徴とするスクリュー圧縮機の容量制御装置。 13、請求項11において、上限圧力設定値を予め複数
個用意し、圧縮機負荷に応じて前記上限圧力設定値を切
替えることを特徴とするスクリュー圧縮機の容量制御装
置。 14、請求項11において、無負荷運転時の圧力降下速
度を検出し、無負荷運転から全負荷運転に切替える際に
吐出側圧力が必要最低圧力以下に低下しないように前記
圧力降下速度に応じて下限圧力設定値を補正することを
特徴とするスクリュー圧縮機の容量制御装置。 15、スクリュー圧縮機の吸入側に設けたオンオフ式制
御弁をオンオフさせて全負荷運転及び無負荷運転を実施
するスクリュー圧縮機において、圧縮機負荷側の圧力を
検出する圧力検出器、及び 前記オンオフ式制御弁をオンオフさせるための下限圧力
設定値及び上限圧力設定値を有し、これら圧力設定値と
前記圧力検出器からの圧力値とを比較して前記オンオフ
式制御弁をオンオフ制御すると共に、オンオフ周期が一
定時間以下とならないようにオンオフ式制御弁を制御す
る制御装置を備えていることを特徴とするスクリュー圧
縮機の制御装置。 16、スクリュー圧縮機の吸入側に設けたオンオフ式制
御弁及びその吐出側に設けた放風弁とを備え、圧縮機吐
出側の圧力によつて全負荷運転及び無負荷運転を切替え
て運転するスクリュー圧縮機において、 無負荷運転から全負荷運転に切替えるための下限圧力で
作動する低圧側圧力スイッチ、全負荷運転から無負荷運
転に切替えるための上限圧力で作動する複数個の設定圧
力の異なる高圧側圧力スイッチ、及び、前記複数個の圧
力側圧力スイッチのうち設定圧力の低い方の圧力スイッ
チが作動後の時間を計測するタイマーを備え、前記複数
個の高圧側圧力スイッチとタイマーとにより全負荷運転
と無負荷運転の切替え後一定時間は設定圧力の高い方の
圧力スイッチが作動するまでは全負荷・無負荷の運転切
替えを停止させるように構成したことを特徴とするスク
リュー圧縮機の容量制御装置。[Claims] 1. A screw compressor in which an on-off control valve provided on the suction side of the screw compressor is controlled by pressure on the discharge side of the compressor to perform full load operation and no load operation, Detecting the amount of compressed gas used on the compressor load side, and changing at least one of an upper limit pressure setting value for turning off the on-off control valve and a lower limit pressure setting value for turning on the on-off control valve according to this usage amount. . A method for controlling the capacity of a screw compressor, characterized in that the on-off cycle of the on-off control valve is controlled to be equal to or higher than a predetermined set value. 2. A capacity control method for a screw compressor according to claim 1, characterized in that the amount of compressed gas used on the compressor load side is determined based on the pressure change rate on the compressor load side. 3. In a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off type control valve provided on the suction side of the screw compressor, the pressure on the load side of the compressor is detected and the pressure value is determined. When the upper limit pressure set value is reached, the on-off type control valve is turned off and the compressor is operated with no load,
When the detected pressure value reaches a lower limit pressure set value, the on-off control valve is turned on to operate the compressor at full load, and the length of the on-off cycle of the on-off control valve is within a set range. A capacity control method for a screw compressor, comprising correcting the upper limit pressure set value. 4. A capacity control method for a screw compressor according to claim 3, characterized in that the upper limit pressure setting value is corrected so that the length of the on-off cycle of the on-off control valve is constant. 5. In a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off control valve provided on the suction side of the screw compressor, pressure detection means for detecting the pressure on the load side of the compressor; A control means having an upper limit pressure setting value and a lower limit pressure setting value for turning on and off the on-off type control valve, and comparing these pressure setting values with a pressure value from the pressure detection means to turn on and off the on-off type control valve; and a set value correction means for correcting at least one of the upper limit pressure set value and the lower limit pressure set value so that the on/off cycle of the on-off type control valve is equal to or higher than the set value. Capacity control device. 6. In a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off type control valve provided on the suction side of the screw compressor, a pressure detector for detecting the pressure on the load side of the compressor; Control that has a lower limit pressure set value and an upper limit pressure set value for turning on and off the on-off type control valve, and controls the on-off type control valve on and off by comparing these pressure set values and the pressure value from the pressure detector. a device, a means for detecting the magnitude of the load on the compressor load side, and an on-off type that corrects at least one of the upper limit pressure set value or the lower limit pressure set value according to the magnitude of the load from the load detection means; 1. A capacity control device for a screw compressor, comprising set value correction means for setting the on/off cycle of a control valve to a predetermined set value or more. 7. In a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off type control valve provided on the suction side of the screw compressor, a pressure detector for detecting the pressure on the load side of the compressor; It has a lower limit pressure setting value and an upper limit pressure setting value to turn on and off the on-off type control valve. A control device that controls the on-off type control valve on and off by comparing these pressure set values and the pressure value from the pressure detector, and a control device that controls the on-off type control valve so that the length of the on-off cycle of the on-off type control valve falls within a set range. A capacity control device for a screw compressor, comprising: set value correction means for correcting an upper limit pressure set value. 8. The capacity of a screw compressor according to claim 7, wherein the set value correction means corrects the upper limit pressure set value according to the amount of compressed gas used (load size) on the compressor load side. Control device. 9. A capacity control device for a screw compressor according to claim 8, wherein the amount of compressed gas used on the compressor load side is determined based on the pressure change rate on the compressor load side. 10.Equipped with an on-off type control valve provided on the suction side of the screw compressor and a blowoff valve provided on the discharge side thereof, and operates by switching between full load operation and no-load operation depending on the pressure on the compressor discharge side. In a screw compressor, at least one of the upper limit pressure setting value for switching from full load operation to no-load operation or the lower limit pressure setting value for switching from no-load operation to full-load operation is set to a setting value that changes the switching cycle between full-load operation and no-load operation. A capacity control device for a screw compressor, characterized in that it is configured to perform correction according to the magnitude of compressor load as described above. 11. The screw according to claim 10, wherein the lower limit pressure setting value is constant, and only the upper limit pressure setting value is corrected according to the compressor load so that the full load/no-load switching cycle is within the set range. Compressor capacity control device. 12. In claim 10 or 11, the compressor load is
A capacity control device for a screw compressor, characterized in that the rate of change in pressure on the discharge side of the compressor is detected and determined during at least one of full-load operation and no-load operation. 13. The capacity control device for a screw compressor according to claim 11, wherein a plurality of upper limit pressure set values are prepared in advance, and the upper limit pressure set values are switched according to the compressor load. 14. In claim 11, the pressure drop rate during no-load operation is detected, and the pressure drop rate is determined according to the pressure drop rate so that the discharge side pressure does not fall below the required minimum pressure when switching from no-load operation to full-load operation. A capacity control device for a screw compressor, characterized by correcting a lower limit pressure set value. 15. In a screw compressor that performs full-load operation and no-load operation by turning on and off an on-off type control valve provided on the suction side of the screw compressor, a pressure detector that detects pressure on the load side of the compressor, and the on-off control valve provided on the suction side of the screw compressor. It has a lower limit pressure set value and an upper limit pressure set value for turning the on-off type control valve on and off, and controls the on-off type control valve on and off by comparing these pressure set values and the pressure value from the pressure detector, A control device for a screw compressor, comprising a control device that controls an on-off type control valve so that an on-off cycle does not become less than a certain time. 16.Equipped with an on-off type control valve provided on the suction side of the screw compressor and a blowoff valve provided on the discharge side thereof, and operates by switching between full-load operation and no-load operation depending on the pressure on the compressor discharge side. In screw compressors, there is a low-pressure side pressure switch that operates at the lower limit pressure to switch from no-load operation to full-load operation, and multiple high-pressure switches with different set pressures that operate at the upper limit pressure to switch from full-load operation to no-load operation. A side pressure switch and a timer for measuring the time after the pressure switch with the lower set pressure among the plurality of pressure side pressure switches is activated, and the plurality of high pressure side pressure switches and the timer are used to control the full load. Capacity control of a screw compressor, characterized in that the switching between full load and no load operation is stopped for a certain period of time after switching between operation and no load operation until the pressure switch with the higher set pressure is activated. Device.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP02284279A JP3125794B2 (en) | 1990-10-24 | 1990-10-24 | Method and apparatus for controlling capacity of screw compressor |
DE1991607010 DE69107010T2 (en) | 1990-10-24 | 1991-10-22 | Method and device for controlling the volume of a compressor. |
EP19910118009 EP0482592B1 (en) | 1990-10-24 | 1991-10-22 | Compressor capacity control method and apparatus therefor |
KR1019910018706A KR950013891B1 (en) | 1990-10-24 | 1991-10-24 | Compressor capacity control method and apparatus |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP02284279A JP3125794B2 (en) | 1990-10-24 | 1990-10-24 | Method and apparatus for controlling capacity of screw compressor |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH04159491A true JPH04159491A (en) | 1992-06-02 |
JP3125794B2 JP3125794B2 (en) | 2001-01-22 |
Family
ID=17676478
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP02284279A Expired - Lifetime JP3125794B2 (en) | 1990-10-24 | 1990-10-24 | Method and apparatus for controlling capacity of screw compressor |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0482592B1 (en) |
JP (1) | JP3125794B2 (en) |
KR (1) | KR950013891B1 (en) |
DE (1) | DE69107010T2 (en) |
Cited By (6)
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JP2002098084A (en) * | 2000-09-20 | 2002-04-05 | Hitachi Ltd | Screw compression equipment and its operating method |
JP2007085360A (en) * | 1996-02-19 | 2007-04-05 | Hitachi Industrial Equipment Systems Co Ltd | Method for operating screw compressor |
JP2007198199A (en) * | 2006-01-25 | 2007-08-09 | Hitachi Industrial Equipment Systems Co Ltd | Capacity control device and capacity control method for screw compressor |
JP2010185458A (en) * | 1996-02-19 | 2010-08-26 | Hitachi Industrial Equipment Systems Co Ltd | Method of operating screw compressor |
JP2015048816A (en) * | 2013-09-04 | 2015-03-16 | 株式会社神戸製鋼所 | Compressor and its pressure control method |
CN106368940A (en) * | 2016-09-29 | 2017-02-01 | 北京宇航***工程研究所 | Pressurization system for piston pump and implementation method of pressurization system |
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US5401149A (en) * | 1992-09-11 | 1995-03-28 | Hitachi, Ltd. | Package-type screw compressor having coated rotors |
US5343384A (en) * | 1992-10-13 | 1994-08-30 | Ingersoll-Rand Company | Method and apparatus for controlling a system of compressors to achieve load sharing |
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US6206652B1 (en) | 1998-08-25 | 2001-03-27 | Copeland Corporation | Compressor capacity modulation |
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DE764179C (en) * | 1938-12-28 | 1953-04-27 | Klein | Compressor system with pressure control |
JPS56143392A (en) * | 1980-04-09 | 1981-11-09 | Hitachi Ltd | Device for monitoring screw compressor |
JPS5870078A (en) * | 1981-10-21 | 1983-04-26 | Hitachi Ltd | Supervising apparatus for screw compressor |
JPS58167890A (en) * | 1982-03-29 | 1983-10-04 | Hitachi Ltd | Control for compressor |
JPS60243397A (en) * | 1984-05-17 | 1985-12-03 | Kobe Steel Ltd | Controlling method of capacity of centrifugal compressor |
JP2737254B2 (en) * | 1989-06-08 | 1998-04-08 | 北越工業株式会社 | Switching method of compressor capacity control |
-
1990
- 1990-10-24 JP JP02284279A patent/JP3125794B2/en not_active Expired - Lifetime
-
1991
- 1991-10-22 EP EP19910118009 patent/EP0482592B1/en not_active Expired - Lifetime
- 1991-10-22 DE DE1991607010 patent/DE69107010T2/en not_active Expired - Lifetime
- 1991-10-24 KR KR1019910018706A patent/KR950013891B1/en not_active IP Right Cessation
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2007085360A (en) * | 1996-02-19 | 2007-04-05 | Hitachi Industrial Equipment Systems Co Ltd | Method for operating screw compressor |
JP2010185458A (en) * | 1996-02-19 | 2010-08-26 | Hitachi Industrial Equipment Systems Co Ltd | Method of operating screw compressor |
JP2012067759A (en) * | 1996-02-19 | 2012-04-05 | Hitachi Industrial Equipment Systems Co Ltd | Screw compressor |
JP2002098084A (en) * | 2000-09-20 | 2002-04-05 | Hitachi Ltd | Screw compression equipment and its operating method |
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US6599094B2 (en) | 2000-09-20 | 2003-07-29 | Hitachi, Ltd. | Screw compressor system and operating method thereof |
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JP2007198199A (en) * | 2006-01-25 | 2007-08-09 | Hitachi Industrial Equipment Systems Co Ltd | Capacity control device and capacity control method for screw compressor |
JP2015048816A (en) * | 2013-09-04 | 2015-03-16 | 株式会社神戸製鋼所 | Compressor and its pressure control method |
CN106368940A (en) * | 2016-09-29 | 2017-02-01 | 北京宇航***工程研究所 | Pressurization system for piston pump and implementation method of pressurization system |
Also Published As
Publication number | Publication date |
---|---|
JP3125794B2 (en) | 2001-01-22 |
EP0482592B1 (en) | 1995-01-25 |
EP0482592A1 (en) | 1992-04-29 |
DE69107010T2 (en) | 1995-08-24 |
KR950013891B1 (en) | 1995-11-17 |
DE69107010D1 (en) | 1995-03-09 |
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