CN103644090B - A kind of liquid vapour jet-type takes out negative pressure system and controlling method thereof - Google Patents
A kind of liquid vapour jet-type takes out negative pressure system and controlling method thereof Download PDFInfo
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- CN103644090B CN103644090B CN201310631928.5A CN201310631928A CN103644090B CN 103644090 B CN103644090 B CN 103644090B CN 201310631928 A CN201310631928 A CN 201310631928A CN 103644090 B CN103644090 B CN 103644090B
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Abstract
The invention provides a kind of liquid vapour jet-type and take out negative pressure system and controlling method thereof, this is taken out negative pressure system and comprises water ejector, drying cylinder, flash drum, injection water tank and water pump; Wherein, the outlet of drying cylinder is connected with the entrance of flash drum, the outlet of flash drum is connected with the gas access of water ejector, and the liquid outlet of water ejector is connected with injection water tank, and the outlet of spraying water tank is connected with the liquid inlet of water ejector by water pump; Its controlling method is, the differential pressure signal of drying cylinder two ends setting is input signal, the actual differential pressure signal at the drying cylinder two ends that differential pressure transmitter records is feedback signal, the deviate of input signal and feedback signal is after sublevel PID controller calculates, export the output frequency that control signal controls frequency variator, and then realize controlling the rotating speed of water pump, water pump sprays the water of water tank with the suction of the speed of setting, realizes this and takes out negative pressure system suction secondary steam.The efficiency that the invention enables drying cylinder secondary steam to aspirate is further enhanced.
Description
[technical field]
The invention belongs to pulp technology for making paper, be specifically related to a kind of liquid vapour jet-type and take out negative pressure system and controlling method thereof.
[background technique]
The steam that paper machine dryer steam water interface is out undertaken getting rid of after carbonated drink is separated by flash drum is referred to as secondary steam, in low-temperature zone, secondary steam is outwards aspirated by water ring vaccum pump traditionally, to ensure the degree of vacuum in flash drum, but due to secondary steam temperature higher, easily cause water ring vaccum pump temperature distortion and damage, bring production suspension induced losses to enterprise, meanwhile, water ring vaccum pump consumed power is larger, general at about 15KW, and price is costly.In addition, the control usually for water ring vaccum pump only comprises startup and stops two states, and it can only provide certain suction force and can not change according to actual conditions, and needs the water quality entered wherein to be purification soft water, otherwise can cause damage to its parts.Taking out negative pressure system with liquid vapour jet-type replaces water ring vaccum pump suction secondary steam can avoid above deficiency, the differential pressure of adding the drying cylinder two ends needed for different paper kind is in a certain scope instead of a value determined, thus, cause pressure difference in the fatigue damage of water pump and water ejector constantly to change the damage caused it because pump rotary speed constantly changes.
[summary of the invention]
The object of the invention is to the defect overcoming above-mentioned prior art, provide a kind of liquid vapour jet-type and take out negative pressure system and controlling method thereof, efficiency that negative pressure system and controlling method thereof make drying cylinder secondary steam aspirate is further enhanced to adopt this to take out, thus avoids water pump in the problem and water ejector of running medium speed frequent variations because negative pressure constantly changes the damage caused it.
For achieving the above object, present invention employs following technological scheme:
A kind of liquid vapour jet-type takes out negative pressure system, comprises water ejector, drying cylinder, flash drum, injection water tank and water pump; Wherein, the outlet of drying cylinder is connected with the entrance of flash drum, the outlet of flash drum is connected with the gas access of water ejector, and the liquid outlet of water ejector is connected with injection water tank, and the outlet of spraying water tank is connected with the liquid inlet of water ejector by water pump.
The present invention improves further and is: described water pump is provided with the Frequency Converter Control for regulating pump rotary speed.
The present invention improves further and is: described frequency variator adopts Parameter adjustable sublevel PID controller.
The present invention improves further and is: be provided with differential pressure transmitter between the entrance of drying cylinder and outlet, the output terminal of differential pressure transmitter is connected with frequency variator by regulator.
The present invention improves further and is: be provided with the safety check preventing secondary steam suck-back between the outlet of described flash drum and the gas access of water ejector.
Another object of the present invention, a kind of liquid vapour jet-type takes out the controlling method of negative pressure system, the differential pressure signal of drying cylinder two ends setting is input signal, the actual differential pressure signal at the drying cylinder two ends that differential pressure transmitter records is feedback signal, the deviate e of input signal and feedback signal is after sublevel PID controller calculates, export the output frequency that control signal u controls frequency variator, and then realize controlling the rotating speed of water pump, the water that water pump sprays water tank with the suction of the speed of setting reaches the pressure controlling water ejector, realizes this and takes out negative pressure system suction secondary steam.
The present invention improves further and is: the differential pressure at setting drying cylinder two ends is P, and the actual differential pressure when the drying cylinder two ends recorded is P
1if, 0 < P
1during≤P/2, sublevel PID regulator is according to the deviate e of input
1adjustment parameter, exports control signal u
1control the output frequency of frequency variator, and then control pump rotary speed is v
1;
Actual differential pressure when the drying cylinder two ends recorded is P
1if, P/2 < P
1during≤P, sublevel PID regulator is according to the deviate e of input
2adjustment parameter, exports control signal u
2control the output frequency of frequency variator, and then control pump rotary speed is reduced to v
2;
Actual differential pressure when the drying cylinder two ends recorded is P
1if, P < P
1during≤3/2P, sublevel PID regulator is according to the deviate e of input
3adjustment parameter, exports control signal u
3control the output frequency of frequency variator, and then control pump rotary speed is reduced to speed v
3;
Actual differential pressure when the drying cylinder two ends recorded is P
1if, 3/2P < P
1during≤2P, sublevel PID regulator is according to the deviate e of input
4adjustment parameter, exports control signal u
4control the output frequency of frequency variator, and then control pump rotary speed is reduced to speed v
4;
When the actual differential pressure at the drying cylinder two ends recorded is identical with its setting value, sublevel PID regulator controls the output frequency of frequency variator with control signal on last stage, pump rotary speed with identical on last stage, wherein, control signal u
4, u
3, u
2and u
1for current signal, and u
4< u
3< u
2< u
1, v
4< v
3< v
2< v
1.
Compared with prior art, beneficial effect of the present invention is embodied in:
The present invention adopts a kind of liquid vapour jet-type to take out negative pressure system to replace traditional water ring vaccum pump, and in secondary steam aspiration procedure, add the design of control loop and Parameter adjustable sublevel PID controller, achieve by the high problem of water ejector equipment reliability, the efficiency that secondary steam is discharged obtains further raising, and avoids water pump and cause its fatigue damage and water ejector constantly to change the problem causing its negative pressure excessive due to pressure at running medium speed frequent changes.
[accompanying drawing explanation]
Fig. 1 is the structural representation that a kind of liquid vapour of the present invention jet-type takes out negative pressure system;
Fig. 2 is the fundamental diagram that a kind of liquid vapour of the present invention jet-type takes out negative pressure system;
Fig. 3 is the signal input/output relation figure of sublevel PID controller of the present invention.
[embodiment]
Below in conjunction with accompanying drawing, the invention will be further described.
Shown in Figure 1, a kind of liquid vapour jet-type takes out negative pressure system, comprises water ejector 1, safety check 2, regulator 3, differential pressure transmitter 4, drying cylinder 5, flash drum 6, sprays water tank 7 and water pump 8.
Wherein, the outlet of drying cylinder 5 is connected with the entrance of flash drum 6, the outlet of flash drum 6 is connected with the gas access of water ejector 1 through preventing the safety check 2 of secondary steam suck-back, the liquid outlet of water ejector 1 is connected with injection water tank 7, and the outlet of spraying water tank 7 is connected by the liquid inlet of water pump 8 with water ejector 1.Water pump 8 is provided with the frequency variator for regulating water pump 8 rotating speed, this frequency variator adopts Parameter adjustable sublevel PID controller to control.Be provided with differential pressure transmitter 4 between the entrance of drying cylinder 5 and outlet, the output terminal of differential pressure transmitter 4 is connected with frequency variator by regulator 3.
A kind of liquid vapour of the present invention jet-type takes out negative pressure system, and its working procedure is:
The secondary steam that the condensed water that drying cylinder 5 is discharged produces after flash drum 6 is inhaled into water ejector 1 by stop valve 2, the water that the outlet of water ejector 1 is flowed out enters injection water tank 7, then the liquid inlet of water ejector 1 is delivered to again by water pump 8, cause water ejector 1 pressure lower than the pressure being evacuated gas, under the effect of this pressure difference, secondary steam is entered in water ejector 1 by injection, mix with water, and taken away by high-speed jet, and then be discharged outside water ejector 1, reach the object of suction secondary steam.Differential pressure transmitter 4 is for measuring the import and export differential pressure of drying cylinder 5, regulator 3 controls the output of frequency variator by receiving drying cylinder 5 two ends differential pressure and the difference of setting differential pressure signal, and then control the rotating speed of jet pump 8, thus change the aspiration of secondary steam by the flow regulating suction to spray water tank 7 li of water.
See Fig. 2, the controlling method that a kind of liquid of the present invention vapour jet-type takes out negative pressure system is as follows, the differential pressure signal of drying cylinder 5 two ends setting is input signal, the actual differential pressure signal at drying cylinder 5 two ends that differential pressure transmitter 4 records is feedback signal, the deviate e of input signal and feedback signal is after sublevel PID controller calculates, export the output frequency that control signal u controls frequency variator, and then realize controlling the rotating speed of water pump 8, the water that water pump 8 sprays water tank 7 with the suction of the speed of setting reaches the pressure controlling water ejector 1, realizes this and takes out negative pressure system suction secondary steam.
See Fig. 3, a kind of liquid vapour of the present invention jet-type takes out the controlling method of negative pressure system, and the differential pressure at setting drying cylinder 5 two ends is P, and the actual differential pressure when drying cylinder 5 two ends recorded is P
1if, 0 < P
1during≤P/2, sublevel PID regulator is according to the deviate e of input
1adjustment parameter, exports control signal u
1control the output frequency of frequency variator, and then control water pump 8 rotating speed is v
1;
Actual differential pressure when drying cylinder 5 two ends recorded is P
1if, P/2 < P
1during≤P, sublevel PID regulator is according to the deviate e of input
2adjustment parameter, exports control signal u
2control the output frequency of frequency variator, and then control water pump 8 rotating speed is reduced to v
2;
Actual differential pressure when drying cylinder 5 two ends recorded is P
1if, P < P
1during≤3/2P, sublevel PID regulator is according to the deviate e of input
3adjustment parameter, exports control signal u
3control the output frequency of frequency variator, and then control water pump 8 rotating speed is reduced to speed v
3;
Actual differential pressure when drying cylinder 5 two ends recorded is P
1if, 3/2P < P
1during≤2P, sublevel PID regulator is according to the deviate e of input
4adjustment parameter, exports control signal u
4control the output frequency of frequency variator, and then control water pump 8 rotating speed is reduced to speed v
4;
When the actual differential pressure at drying cylinder 5 two ends recorded is identical with its setting value, sublevel PID regulator controls the output frequency of frequency variator with control signal on last stage, water pump 8 rotating speed with identical on last stage, wherein, control signal u
4, u
3, u
2and u
1for current signal, deviate e
1, e
2, e
3and e
4be respectively the actual differential pressure at drying cylinder 5 two ends and the difference of its setting value under different conditions, and u
4< u
3< u
2< u
1, v4 < v3 < v2 < v1.
The working principle that a kind of liquid vapour of the present invention jet-type takes out negative pressure system and controlling method thereof is:
The electrical signal that differential pressure changes is delivered to controller by the differential pressure transmitter 4 that the import and export of drying cylinder 5 are installed, according to the differential pressure setpoint at drying cylinder 5 two ends and the deviation size of differential pressure measurement value, according to the sublevel PID Controlling principle from setting, the output frequency of frequency variator is controlled from the on-the-spot practical operation situation of motion tracking, thus control water ejector 1 delivered to by water pump 8 liquid inlet with the water of different speed suction injection 7 li, water tank, and then the pressure of adjustment water ejector 1.Under the effect of certain pressure intensity, export from water ejector 1 water flowed out and potential energy is transformed into kinetic energy, form high-speed jet, define parital vacuum in outlet port, cause its pressure lower than by the pressure of the body that draws gas, under the effect of this pressure difference, secondary steam is entered water ejector 1 by injection, mix with working water and taken away by high-speed jet, then the kinetic energy of fluid-mixing become potential energy and is discharged outside water ejector 1, making it reach the object of suction secondary steam.
Claims (5)
1. liquid vapour jet-type takes out a negative pressure system, it is characterized in that: comprise water ejector (1), drying cylinder (5), flash drum (6), spray water tank (7) and water pump (8); Wherein, the outlet of drying cylinder (5) is connected with the entrance of flash drum (6), the outlet of flash drum (6) is connected with the gas access of water ejector (1), the liquid outlet of water ejector (1) is connected with injection water tank (7), and the outlet of spraying water tank (7) is connected by the liquid inlet of water pump (8) with water ejector (1);
Described water pump (8) is provided with the frequency variator for regulating water pump (8) rotating speed;
Described frequency variator adopts Parameter adjustable sublevel PID controller to control.
2. liquid vapour jet-type according to claim 1 takes out negative pressure system, it is characterized in that: be provided with differential pressure transmitter (4) between the entrance of drying cylinder (5) and outlet, the output terminal of differential pressure transmitter (4) is connected with frequency variator by regulator (3).
3. liquid vapour jet-type according to claim 1 takes out negative pressure system, it is characterized in that: be provided with the safety check (2) preventing secondary steam suck-back between the outlet of described flash drum (6) and the gas access of water ejector (1).
4. liquid vapour jet-type according to claim 2 takes out the controlling method of negative pressure system, it is characterized in that: the differential pressure signal of drying cylinder (5) two ends setting is input signal, the actual differential pressure signal at drying cylinder (5) two ends that differential pressure transmitter (4) records is feedback signal, the deviate e of input signal and feedback signal is after sublevel PID controller calculates, export the output frequency that control signal u controls frequency variator, and then realize controlling the rotating speed of water pump (8), the water that water pump (8) sprays water tank (7) with the speed set suction reaches the pressure controlling water ejector (1), realize this and take out negative pressure system suction secondary steam.
5. liquid vapour jet-type according to claim 4 takes out the controlling method of negative pressure system, it is characterized in that: the differential pressure at setting drying cylinder (5) two ends is P, and the actual differential pressure when the drying cylinder recorded (5) two ends is P
1if, 0 < P
1during≤P/2, sublevel PID regulator is according to the deviate e of input
1adjustment parameter, exports control signal u
1control the output frequency of frequency variator, and then control water pump (8) rotating speed is v
1;
Actual differential pressure when the drying cylinder recorded (5) two ends is P
1if, P/2 < P
1during≤P, sublevel PID regulator is according to the deviate e of input
2adjustment parameter, exports control signal u
2control the output frequency of frequency variator, and then control water pump (8) rotating speed is reduced to v
2;
Actual differential pressure when the drying cylinder recorded (5) two ends is P
1if, P < P
1during≤3/2P, sublevel PID regulator is according to the deviate e of input
3adjustment parameter, exports control signal u
3control the output frequency of frequency variator, and then control water pump (8) rotating speed is reduced to speed v
3;
Actual differential pressure when the drying cylinder recorded (5) two ends is P
1if, 3/2P < P
1during≤2P, sublevel PID regulator is according to the deviate e of input
4adjustment parameter, exports control signal u
4control the output frequency of frequency variator, and then control water pump (8) rotating speed is reduced to speed v
4;
When the actual differential pressure at the drying cylinder recorded (5) two ends is identical with its setting value, sublevel PID regulator controls the output frequency of frequency variator with control signal on last stage, and pump rotary speed is with identical on last stage; Wherein, control signal u
4, u
3, u
2and u
1for current signal, and u
4< u
3< u
2< u
1, v
4< v
3< v
2< v
1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310631928.5A CN103644090B (en) | 2013-11-28 | 2013-11-28 | A kind of liquid vapour jet-type takes out negative pressure system and controlling method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310631928.5A CN103644090B (en) | 2013-11-28 | 2013-11-28 | A kind of liquid vapour jet-type takes out negative pressure system and controlling method thereof |
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| Publication Number | Publication Date |
|---|---|
| CN103644090A CN103644090A (en) | 2014-03-19 |
| CN103644090B true CN103644090B (en) | 2016-04-06 |
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| CN104264525B (en) * | 2014-09-24 | 2016-08-24 | 陕西科技大学 | A kind of paper machine dryer ponding automatic early-warning and the system of elimination and control method |
| CN105864743A (en) * | 2016-05-26 | 2016-08-17 | 清华大学 | Pollution discharge, water and energy saving, recovery and separation device and method of steam injection boiler |
| CN109078350B (en) * | 2018-09-11 | 2021-04-02 | 山东禹王生态食业有限公司 | Food negative pressure flash distillation system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202017162U (en) * | 2011-04-08 | 2011-10-26 | 上海东冠纸业有限公司 | Hot-air drying system for production of household paper |
| CN202522094U (en) * | 2012-03-29 | 2012-11-07 | 陕西科技大学 | Steam-water contact type heat exchanger |
| CN203360927U (en) * | 2013-07-16 | 2013-12-25 | 陕西科技大学 | Liquid-vapor jet type negative pressure pumping device for paper making machine drying system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0333495A (en) * | 1989-06-29 | 1991-02-13 | Toshiba Corp | Control device for condensate pump |
| JPH10274151A (en) * | 1997-03-27 | 1998-10-13 | Nikkiso Co Ltd | Pump unit for straightforward type water supply system |
| WO1999064667A1 (en) * | 1998-06-11 | 1999-12-16 | Sulzer Pumpen Ag | Control system for a vacuum pump used for removing liquid and a method of controlling said pump |
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2013
- 2013-11-28 CN CN201310631928.5A patent/CN103644090B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202017162U (en) * | 2011-04-08 | 2011-10-26 | 上海东冠纸业有限公司 | Hot-air drying system for production of household paper |
| CN202522094U (en) * | 2012-03-29 | 2012-11-07 | 陕西科技大学 | Steam-water contact type heat exchanger |
| CN203360927U (en) * | 2013-07-16 | 2013-12-25 | 陕西科技大学 | Liquid-vapor jet type negative pressure pumping device for paper making machine drying system |
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| CN103644090A (en) | 2014-03-19 |
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