EP0482592B1 - Compressor capacity control method and apparatus therefor - Google Patents

Compressor capacity control method and apparatus therefor Download PDF

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Publication number
EP0482592B1
EP0482592B1 EP19910118009 EP91118009A EP0482592B1 EP 0482592 B1 EP0482592 B1 EP 0482592B1 EP 19910118009 EP19910118009 EP 19910118009 EP 91118009 A EP91118009 A EP 91118009A EP 0482592 B1 EP0482592 B1 EP 0482592B1
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EP
European Patent Office
Prior art keywords
pressure
compressor
load
capacity control
compressor body
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Expired - Lifetime
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EP19910118009
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German (de)
English (en)
French (fr)
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EP0482592A1 (en
Inventor
Seiji Tsuru
Junji Okita
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Hitachi Plant Technologies Ltd
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Hitachi Ltd
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    • 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

Definitions

  • the present invention relates to a method of controlling a capacity of a compressor having an on-off type control valve and an apparatus therefor, more particularly, to a method of controlling a capacity of a rotary displacement type compressor such as a screw type compressor and roots type compressor, and the apparatus therefor.
  • the compressor includes a compressor body, a piping connected with the discharge or outlet side of the compressor body at one end thereof and with a gas consumption side (load side) at the other end thereof, and a capacity control device for controlling the flow rate of the compressed gas (compressor capacity) from the compressor body to the piping at the outlet side of the compressor body.
  • a conventional capacity control apparatus of a screw type compressor having an on-off type control valve includes, for example, as shown in JP-A-58-167890, the on-off control valve arranged at the suction or inlet side of the compressor body and an air vent valve arranged at the discharge or outlet side of the compressor body.
  • the on-off control valve arranged at the suction or inlet side of the compressor body and an air vent valve arranged at the discharge or outlet side of the compressor body.
  • the air pressure at the outlet side of the compressor body is detected by a pressure switch, and according to the value of the detected pressure, a switching command signal is transmitted for switching the compressor body between a full load operation and an unload operation.
  • An object of the present invention is to provide a compressor capacity control method and an apparatus therefor capable of reducing the operation time of the compressor body during which the compressor body produces unnecessarily high pressure, under a condition where the operational load (gas consumption speed or amount/time at the gas consumption side) is varied significantly, or the volume of the piping connected with the outlet side of the compressor body is large, and accordingly, reducing the electric power consumption.
  • Another object of the present invention is to provide a compressor capacity control method and an apparatus therefor in which the switching period between a full load operation and an unload operation of the compressor body is maintained longer than a predetermined time length, thereby improving reliability of the capacity control apparatus while ensuring the pressure at the air consumption side to be maintained over a predetermined minimum level at all times.
  • a capacity control method in which a compressor body is switched between a full load condition and an unload condition by operating an on-off control valve disposed at an inlet side of the compressor body; a pressure (P) at the discharge or load side of the compressor is detected by a pressure sensor, and when the pressure (P) reaches a predetermined upper pressure limit P max , the on-off control valve is made off, thereby putting the compressor body in the unload condition, while when the detected pressure (P) reaches a predetermined lower pressure limit P min , the on-off control valve is made on, thereby putting the compressor body in the full load condition; and magnitude (q) of the load at the load side of the compressor is detected, and according to the magnitude (q) of the load, at least one of the above-mentioned upper limit P max and lower limit P min is changed so as to make an on-off period ( ⁇ t; ⁇ t1) longer than a predetermined set time length value
  • an on-off type capacity control method which is adopted in a capacity control method according to the present invention
  • the on-off control valve when the on-off control valve is put in an "on" condition (open condition) and the compressor body is put in a full load operational condition, the pressure at the load side (outlet side of the compressor body) increases.
  • the on-off control valve When the pressure at the load side reaches a preset or predetermined upper pressure limit, the on-off control valve is put in an "off” condition and the compressor body is switched from the full load operation into an unload operation.
  • the pressure at the load side then decreases at a speed corresponding to the magnitude of the load.
  • the compressor body When the pressure at the load side reaches a preset or predetermined lower pressure limit, the compressor body is switched from the unload operation to the full load operation and the pressure at the load side increases again. The above-mentioned operations are repeated.
  • a capacity control method since the preset upper pressure limit or the preset lower pressure limit, at which value the on-off control valve is put on (opened) or off (closed), is adjusted according to the magnitude of the load, it becomes possible to maintain the switching period between the full load operation and the unload operation longer than a predetermined time length, thereby enhancing the reliability of an apparatus for carrying out the capacity control method of the present invention.
  • on-off period means, in principle, a period ( ⁇ t) including one full load operation time and one unload operation time, these operations being alternatively repeated.
  • the full load period ( ⁇ t1) or the unload period ( ⁇ t - ⁇ t1) is also a time length corresponding to the on-off period.
  • the detection of the magnitude, more specifically relative magnitude, of the load at the load side of the compressor is carried out by detecting the compressed gas consumption rate or ratio (relative to the compressor capacity) (q) at the load side, and the detection of the compressed gas consumption rate or ratio (q) is carried out, for example, by measuring a variation speed (dP/dt) of a pressure (P) at the load side of the compressor, or by measuring the on-off period ( ⁇ t; ⁇ t1) of the on-off control valve.
  • the preset upper pressure limit (P max ) is changed so as to make the measured on-off period ( ⁇ t; ⁇ t1) longer, more specifically not shorter than a predetermined value
  • the preset upper pressure limit (P max ) is determined so as to make the measured on-off period ( ⁇ t; ⁇ t1) coincide with the predetermined value In this case, by making the lower limit of pressure coincide with the pressure level required at the consumption side (load side), a necessary pressure is maintained at all times.
  • a compressor capacity control apparatus including an on-off control valve provided at an inlet side of a compressor body and adapted to be made "on” or “off” for putting the compressor body in a full load condition or in an unload condition, respectively; a pressure detecting means for detecting a pressure (P) at a load side of the compressor; and an on-off control means for effecting an on-off action on the on-off control valve based on a comparison of a preset or predetermined upper pressure limit (P max ) and a preset or predetermined lower pressure limit (P min ) with the detected pressure value (P) detected by said pressure detecting means, characterized in that the control means comprises a load detecting means for detecting a magnitude (q) of a load at the load side of the compressor, and a set value changing means for changing at least one of the preset upper pressure limit (P max ) and the preset lower pressure limit (P min ) so as to make an on-off
  • a capacity control apparatus similarly to in the capacity control method, since the upper pressure limit or the lower pressure limit, at which the on-off control valve is made on or off, is changed according to the magnitude of the load at the load side of the compressor body, the switching period between the full load operation and the unload operation can be changed not shorter than the predetermined time length, thereby enhancing the reliability of the capacity control apparatus. Further, in case of an extremely large (high) or extremely small (low) operational load or a great inside volume of the piping at the outlet side, the upper pressure limit is made or changed lower and the operational time at high pressure can be decreased, thereby further enhancing the energy economizing effect.
  • the load detecting means is composed of a gas consumption rate or ratio detecting means for detecting the gas consumption rate or ratio (q) at the load side of the compressor.
  • the gas consumption rate or ratio detecting means is composed of, for example, (1) a variation speed detecting means for detecting a pressure variation speed (dP/dt) of the compressed gas at the load side of the compressor; (2) a compressed gas flow rate detecting means at the load side of the compressor; or (3) a means for detecting the on-off period ( ⁇ t; ⁇ t1) of the on-off control valve.
  • the set value changing means is so constituted that one of the preset upper limit (P max ) of pressure and the preset lower limit (P min ) of pressure is changed to make the on-off period ( ⁇ t; ⁇ t1) of the on-off control valve not shorter than a predetermined value
  • the set value changing means is so constituted that the upper pressure limit (P max ) is changed to make the on-off period ( ⁇ t; ⁇ t1) of the on-off control valve not shorter than the predetermined value
  • the on-off control means includes a plurality of predetermined upper pressure limits (for example, two limits such as P max1 , P max2 ), and the set value changing means is so constituted as to switch or change the pressure upper limit (P max1 , P max2 ) according to the magnitude (q) of the load on the compressor.
  • the on-off control means comprises a low pressure side pressure switch acting at the pressure lower limit (P min ) for switching the compressor body from the unload operation to the full load operation and a plurality of high pressure side pressure switches acting at the plurality of upper pressure limits (P max1 , P max2 ) for switching the compressor body from the full load operation to the unload operation;
  • the capacity control apparatus further comprises a timer for measuring a time length after an action or actuation of the low pressure side pressure switch; and the set value changing means is constituted so that the high pressure side pressure switches are not actuated before at least the predetermined time length has elapsed after the compressor body is switched from the unload operation to the full load operation by combination of the plurality of high pressure side pressure switches and the timer.
  • the compressor capacity control apparatus further comprises a pressure decreasing speed detecting means for detecting a decreasing speed (dP/dt) of the pressure (P) at the load side of the compressor in the unload condition, and the set value changing means is constituted so as to change the predetermined lower pressure limit (P min ) according to the pressure decreasing speed (dP/dt) of the pressure (P) for preventing the pressure (P) at the load side from decreasing beyond a minimum pressure (P min0 ) required at the load or consumption side when the compressor body is switched from the unload condition to the full load condition.
  • P min predetermined lower pressure limit
  • the capacity control apparatus further comprises an air vent valve at the outlet side of the compressor body, the air vent valve being closed when said on-off valve is made on, while opened when the on-off valve is made off.
  • FIG. 1 a compressor capacity control method and apparatus according to an embodiment of the present invention will be described below.
  • the figure shows mainly an air-related system of a screw compressor 18 including a capacity control apparatus 17.
  • reference numeral 1 denotes a compressor body
  • numeral 2 denotes a suction valve as an on-off valve disposed at an inlet side of the compressor body 1 and actuated between an open position and a closed position by means of a rod 4a of a hydraulic cylinder device 4.
  • Reference numeral 19 denotes a suction filter disposed on the way or passage from an inlet port 14 to the suction valve 2.
  • Numeral 13 denotes a non-return or check valve disposed at an outlet or discharge side of the compressor body 1, while numeral 12 denotes an after-cooler for cooling a compressed or pressurized gas or an exhausted from the compressor body 1.
  • Reference numeral 11 denotes an accumulator for storing the compressed air cooled by the after-cooler 12, the compressed air in the accumulator 11 being taken out through a consumption line 16 and offered to use.
  • Reference numeral 8 denotes a pressure sensor for detecting the pressure P in an outlet line 8a, information of the pressure P detected by the pressure sensor 8 being transmitted to a control device 9.
  • Reference numeral 3 denotes an air vent valve actuated between an open position and a closed position by means of the rod 4a of the hydraulic cylinder device 4 similarly to the suction valve 2, and numeral 15 denotes an air vent silencer disposed between an outlet side of the air vent valve 3 and the air vent port 15.
  • reference numeral 7 denotes an oil sump
  • numeral 6 denotes hydraulic pump
  • numeral 5 denotes a four-way electromagnetic valve, which is operated under a command or instruction or control of the control device 9 so as to select one of three operational positions thereof, thereby moving the rod 4a upwards for downwards, or stopping the same through the hydraulic cylinder device 4.
  • the capacity control apparatus 17 is composed of the valves 2, 3, the cylinder device 4, the pump 6, the oil sump 7, the pressure sensor 8, and the control device 9.
  • a piping 17a at the outlet side is composed of the after-cooler 12 disposed downstream of the non-return valve 13, the air accumulator 11 and the piping 8a connecting these components.
  • the compressor body 1 has been selected so as to have a sufficient discharge capacity.
  • This pressure P at the load side is detected by the pressure sensor 8, and the detected pressure value P is sent to the control device 9.
  • the control device 9 transmits a command or control signal for switching the oil path in the four-way electromagnetic valve 5 and actuating the hydraulic cylinder 4 for moving the rod 4a, thereby putting the suction valve 2 in the closed position and, at the same time, the air vent valve 3 in the open position, resulting in an unload operational condition of the compressor body 1.
  • the pressure P in the outlet side piping system 17a including the air accumulator 11, namely, the pressure P at the load side of the compressor 18 gradually decreases.
  • the control device 9 is so constructed that, when the pressure P decreases and reaches a preset or predetermined lower pressure limit P min , the four-way electromagnetic valve 5 is switched over so as to put the compressor body 1 in the full load condition again.
  • Fig. 5 is a block diagram showing a concrete example of the control device 9 shown in Fig. 1.
  • the control device 9 comprises a A/D (analogue-to-digital) converter 91 serving as a part of a pressure detector, ROM (read only memory) 93 and RAM (random access memory) 94 serving as a memory unit and a central processor 92 including a timer or time measuring part 92a and an arithmetic processing part 92b.
  • the pressure value P detected by the pressure sensor 8 is converted from an analog signal to a digital signal by the A/D converter 91, and sent to the central processor or central processing unit 92.
  • the central processing unit 92 composed, for example, of a microprocessor and including the timer 92a executes comparison and other processing utilizing the pressure signal P and the measured or counted time signal t, and then transmits an on-off command signal for controlling the capacity control valve composed by the valves 2 and 3.
  • the ROM 93 stores preset or predetermined values such as P min , P max and ⁇ t min which will be explained later, while the RAM 94 temporarily stores information such as operation or processing results.
  • the switching period ⁇ t depends on a relative magnitude of load, i.e. a consumption rate or ratio of the compressed gas relative to a compressor capacity.
  • the pressure difference ⁇ P between the predetermined upper pressure limit P max and the predetermined lower pressure limit P min is so changed or reset the switching period ⁇ t fall within a predetermined range ⁇ t min - ⁇ t max (in the example in Fig.
  • ⁇ t becomes equal to ⁇ t min ). Then, at least one of the P max and P min is changed and compared with the detected pressure value P, and a switching command signal for the four-way valve 5 is delivered.
  • the time lengths of ⁇ t1, and ⁇ t2 may be repeatedly measured for a suitable period of time, and an average value in several cycles may be determined. This average switching period ⁇ t is compared with the predetermined value ⁇ t min , and the pressure difference ⁇ P is so changed, if necessary, that the relation ⁇ t min ⁇ ⁇ t ⁇ ⁇ t max can be satisfied.
  • Fig. 2 shows an example of a processing flow of the operation in the control device 9.
  • the upper pressure limit P max or the pressure difference ⁇ P namely, P max - P min
  • the value of ⁇ t min is determined in consideration of conditions such as the minimum operational speeds of the valves 2, 3 of the capacity control device 17. If suitable or desired, other operational factors may be taken into consideration.
  • There should be firstly set the predetermined lower pressure limit P min , an initial set value of ⁇ P, and the minimum period value ⁇ t min (step 20), where the upper pressure limit P max P min + ⁇ P .
  • step 23 in case of ⁇ t ⁇ ⁇ t min or ⁇ t > ⁇ t min , the pressure difference ⁇ P is changed to ⁇ P' defined as follows (step 24b or 24c respectively):
  • the processing is returned to the step 21 so that the above-mentioned control is continuously effected.
  • Figs. 3A and 3B are graphs showing a time-dependent variation of the pressure P at the outlet side and a time-dependent variation of the power L or the energy required per unit time for driving the compressor body 1 in the above-mentioned embodiment where the lower pressure limit P min is fixed while only the upper pressure limit P max is changed based on the reset or changed data ⁇ P'.
  • ⁇ t may be controlled to be slightly longther than ⁇ t min . Further, it is also possible to set an upper limit ⁇ t max for ⁇ t so as to prevent an excessive increase of ⁇ t and to maintain ⁇ t shorter than ⁇ t max . Further, it may be also possible to similarly control ⁇ P (P min ) while maintaining P max constant instead of maintaining P min constant and changing P max . In this case, however, it is preferred to control P min not to be lower than a necessary minimum pressure P min0 .
  • the curve b in Fig. 3 shows a time-dependent variation of the pressure P at the outlet side and a time-dependent variation of the power L, when the lower pressure limit P min is fixed and the pressure difference ⁇ P is decreased so as to approach ⁇ P', smaller than the value in the before-mentioned curve a .
  • the average powers in cases of the curves a and b are compared with each other as follows, assuming the time-dependent variation of the power L is substantially linear: Average power L ave for curve a Average power L' ave for curve b where,
  • ⁇ P dP/dt1(1 - K dP/dt1) ⁇ t
  • ⁇ P min dP/dt1 (1 - K dP/dt1) ⁇ t min (11)
  • ⁇ P min dP/dt2 (1 - K dP/dt2) ⁇ t min (11')
  • ⁇ t1 and ⁇ t2 are measured only for relatively short period, for example, ⁇ t1 + ⁇ t2, or n ( ⁇ t1 + ⁇ t2), n being 2 or 3, after an operation start of the compressor (27a).
  • the constant K dependent on the volume V of the actual piping 17a including the volume of the consumption line 16 is determined (27b).
  • changing speed dP/dt1 or dP/dt2 of the pressure P is measured (27c).
  • ⁇ P min is calculated (27d) based on equations (11) and (12) including parameters the constant K and the set value t min .
  • the pressure difference ⁇ P is set at an optimal value ⁇ P min at which ⁇ t becomes equal to ⁇ t min at all times even when the air consumption ratio q continuously changes.
  • the measurement of dP/dt1 or dP/dt2 is carried out by sampling the values of the pressure P detected by the pressure sensor 8 with desired time intervals ⁇ t by use of the processor 92, and obtaining ⁇ P/ ⁇ t by use of the pressure difference ⁇ P between pressures at two adjacent sampling points.
  • step 25a the relation between the pressure decreasing speed dP/dt and the pressure difference ⁇ Pc exceeding the pressure lower limit P min is measured in advance and stored in the memory 93 or 94 in form of a table or an equation (step 25a in Fig. 4A).
  • dP/dt is detected in operation (step 25b), and the set pressure lower limit is changed from a value P min to a value P o for making the extreme minimum value of the pressure P at the outlet side equal to P min0 (step 25c).
  • P o P min0 + ⁇ Pc
  • the affix "i" means a set of data measured and stored in advance in the step 25a.
  • a set of data approximate to the value of dP/dt measured in the step 25b may be selected.
  • ⁇ Pc may be obtained through an interpolation using two sets of stored data.
  • the relative magnitude of the load namely air consumption ratio q can be determined based on the air flow rate Q L through the line 16 detected by the flow meter 8b, which corresponds to the magnitude of the load.
  • Fig. 6 is a flowchart in case the control device 9 includes a time counting section and pressure switch means capable of setting two kinds (P max1 , P max2 ) of the pressure upper limit P max .
  • a step 30 two upper pressure limits P max1 and P max2 (P max1 ⁇ P max2 ) and a minimum value of ⁇ t1 are set in advance.
  • P max1 is set, for example, at a pressure level which the pressure P at the outlet side reaches when ⁇ t1 becomes substantially equal to under a usual magnitude load
  • P max2 is set at a pressure level which the pressure P at the outlet side reaches when ⁇ t1 becomes substantially equal to in in case of a very small load, for example, in case the compressed gas is not consumed in fact.
  • the full load operation of the compressor body 1 is started, the measurement of the pressure P at the outlet side and the measurement of the time length t after starting are started.
  • a step 32 the measured pressure P is compared with the lower one P max1 of the set upper pressure limits. In case P ⁇ P max1 , the processing is returned to the step 31, and the steps 31 and 32 are repeated until P becomes equal to P max1 , strictly spearing, P becomes equal to or greater than P max1 .
  • the processing advances to a step 33, where the latest measured value t is compared with the smallest switching time length When the t is greater than the smallest switching time length Namely, when the magnitude of the load or the relative magnitude q is substantially equal to an assumed one, the processing advances to a step 35, where the compressor body 1 is switched to an unload operation.
  • the (relative) magnitude of the load is evaluated in the steps 32 and 33.
  • the processing advances to a step 34, where the detected pressure P is compared with the upper one P max2 of the set upper pressure limits.
  • the steps 31 to 34 are repeated until the condition P ⁇ P max2 has been satisfied, as continuing the full load operation.
  • P becomes equal to or greater than P max2 namely when the t becomes substantially equal to the processing advances to the step 35, where the compressor body 1 is switched to the unload operation.
  • the set value is determined in due consideration of the mechanical restriction for timing lengths required for actuating the on-off type control valve 2 and the air vent valve 3 and of a compromise between the merit obtained when the on-off switching period is excessively short and the demerit of the significant reduction in mechanical life of the control valves 2 and 3, the electromagnetic valve 5 thereby and so on.
  • Fig. 7 is an illustration showing an electric circuit 9a which can be used, instead of the control device 9 in Fig. 1, for the embodiment shown in Fig. 6.
  • the pressure switch 40 is a differential pressure switch (Fig. 7A) having a hystreresis feature of making the switch "on” when the detected pressure value P is smaller than P min , and making "off” when the detected pressure value P is beyond P max1 .
  • the pressure switch 41 is a differential pressure switch (Fig. 7B) having a hystreresis feature of making the switch "on” when the detected pressure value P is smaller than P min , and making off when the detected pressure value P is beyond P max2 .
  • Numeral 42 denotes a relay for making on or off a switch P1X
  • numeral 43 a relay for making on or off a switch P2X
  • numeral 44 a relay for making on or off a switch 46X
  • Numeral 45 denotes a timer which starts to count time when the switch 46X is made on, which makes the normally-closed switch T off when the time length reaches the predetermined set value
  • Reference characters 5a denotes a solenoid of the electromagnetic valve 5 in Fig. 1, and reference characters 5b a surge absorber.
  • the electric power supply line 48 is energized when the compressor body 1 starts operating.
  • a control device for controlling the on-off type control valve is constituted only by a plurality of pressure switches and a simple electric circuit, thereby effecting an energy economy at low cost and providing an apparatus in which the switching period between the full load operation and the unload operation can be maintained above the predetermined value.
  • the set lower pressure limit or the set upper pressure limit is changed for controlling the on-off type control valve at the inlet side of the compressor body in dependence on the compressed gas consumption flow rate or ratio or the magnitude of the load, it becomes possible to maintain the switching period between the full load operation and the unload operation greater than the predetermined value, and to prevent a frequent switching of operations even in case of a high load, thereby enhancing the reliability of the apparatus.
  • the pressure level required by the gas consumption side can be maintained at all times.
  • the set upper pressure limit becomes lower in case of a extremely large or extremely small operational load or of a great inside volume of the piping system at the outlet side, an compressor operation time operated in a high pressure is decreased, thereby enhancing the energy economizing effect.

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  • 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)
EP19910118009 1990-10-24 1991-10-22 Compressor capacity control method and apparatus therefor Expired - Lifetime EP0482592B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP02284279A JP3125794B2 (ja) 1990-10-24 1990-10-24 スクリュー圧縮機の容量制御方法及び装置
JP284279/90 1990-10-24

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EP0482592A1 EP0482592A1 (en) 1992-04-29
EP0482592B1 true EP0482592B1 (en) 1995-01-25

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USRE44636E1 (en) 1997-09-29 2013-12-10 Emerson Climate Technologies, Inc. Compressor capacity modulation
US8894381B2 (en) 2009-12-02 2014-11-25 Anest Iwata Corporation Compressor capacity control method and device for controlling the capacity of a compressor

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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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JP4520608B2 (ja) * 2000-09-20 2010-08-11 株式会社日立プラントテクノロジー スクリュー圧縮装置
JP2007198199A (ja) * 2006-01-25 2007-08-09 Hitachi Industrial Equipment Systems Co Ltd スクリュー圧縮機の容量制御装置及び容量制御方法
US8157538B2 (en) 2007-07-23 2012-04-17 Emerson Climate Technologies, Inc. Capacity modulation system for compressor and method
US8308455B2 (en) 2009-01-27 2012-11-13 Emerson Climate Technologies, Inc. Unloader system and method for a compressor
JP2012127253A (ja) * 2010-12-15 2012-07-05 Kobe Steel Ltd スクリュ圧縮機
CN103291595A (zh) * 2013-06-24 2013-09-11 中国石化集团南京化学工业有限公司 高压煤浆泵超压保护系统改进装置
JP5896965B2 (ja) * 2013-09-04 2016-03-30 株式会社神戸製鋼所 圧縮機およびその圧力制御方法
JP6220303B2 (ja) * 2014-03-27 2017-10-25 株式会社神戸製鋼所 圧縮装置および圧縮装置の制御方法
CN106368940B (zh) * 2016-09-29 2018-02-09 北京宇航系统工程研究所 一种用于活塞泵的增压系统及其实现方法
CN110454370B (zh) * 2019-08-19 2020-11-10 蘑菇物联技术（深圳）有限公司 一种动态优化空压站联控压力带的方法
CN110454371B (zh) * 2019-08-19 2021-04-06 蘑菇物联技术（深圳）有限公司 一种在空压站联控时动态匹配下限压力的方法

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USRE44636E1 (en) 1997-09-29 2013-12-10 Emerson Climate Technologies, Inc. Compressor capacity modulation
US8894381B2 (en) 2009-12-02 2014-11-25 Anest Iwata Corporation Compressor capacity control method and device for controlling the capacity of a compressor

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EP0482592A1 (en) 1992-04-29
DE69107010D1 (de) 1995-03-09
JP3125794B2 (ja) 2001-01-22
DE69107010T2 (de) 1995-08-24
KR950013891B1 (ko) 1995-11-17
JPH04159491A (ja) 1992-06-02

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