CN103644090A - Liquid-gas jet type negative pressure pumping system and control method thereof - Google Patents
Liquid-gas jet type negative pressure pumping system and control method thereof Download PDFInfo
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- CN103644090A CN103644090A CN201310631928.5A CN201310631928A CN103644090A CN 103644090 A CN103644090 A CN 103644090A CN 201310631928 A CN201310631928 A CN 201310631928A CN 103644090 A CN103644090 A CN 103644090A
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- drying cylinder
- water
- negative pressure
- differential pressure
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Abstract
The invention provides a liquid-gas jet type negative pressure pumping system and a control method of the liquid-gas jet type negative pressure pumping system. The liquid-gas jet type negative pressure pumping system comprises a water ejector, a drying cylinder, a flash tank, an ejection water tank and a water pump. An outlet of the drying cylinder is connected with an inlet of the flash tank, an outlet of the flash tank is connected with a gas inlet of the water ejector, a liquid outlet of the water ejector is connected with the ejection water tank, and an outlet of the ejector water tank is connected with a liquid inlet of the water ejector through the water pump. The control method of the liquid-gas jet type negative pressure pumping system comprises the steps that differential pressure signals set at the two ends of the drying cylinder are input signals, actual differential pressure signals, measured by a differential pressure transmitter, of the two ends of the drying cylinder are feedback signals, after deviation values of the input signals and the feedback signals are calculated by a sublevel PID controller, control signals are output so that the output frequency of a frequency converter can be controlled and rotation speed of the water pump can be controlled, water in the ejection water tank is pumped by the water pump at a set speed, and secondary steam is pumped through the liquid-gas jet type negative pressure pumping system. According to the liquid-gas jet type negative pressure pumping system and the control method of the liquid-gas jet type negative pressure pumping system, the secondary steam pumping efficiency of the drying cylinder is further improved.
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]
Paper machine dryer steam water interface out carries out by flash drum the steam that carbonated drink separation gets rid of afterwards and is referred to as secondary steam, in low-temperature zone, secondary steam is outwards aspirated by water ring vaccum pump traditionally, to guarantee the degree of vacuum in flash drum, but because secondary steam temperature is higher, easily cause water ring vaccum pump temperature distortion and damage, to enterprise, bring production suspension induced losses, meanwhile, water ring vaccum pump consumed power is larger, generally in about 15KW, and price is comparatively expensive.In addition, conventionally for the control of water ring vaccum pump, only comprise and start and stop two states, it can only provide certain suction force and can not change according to actual conditions, and need to enter water quality wherein for purifying soft water, otherwise can cause damage to its parts.With liquid vapour jet-type, taking out negative pressure system replaces water ring vaccum pump suction secondary steam can avoid above deficiency, the differential pressure of adding the required drying cylinder two ends of different paper kinds is in a certain scope rather than a definite value, thereby, because pump rotary speed constantly changes to cause the fatigue damage of water pump and spray pressure difference in hydrophone, constantly change the damage that it is caused.
[summary of the invention]
The object of the invention is to overcome the defect of above-mentioned prior art, provide a kind of liquid vapour jet-type to take out negative pressure system and controlling method thereof, adopt this to take out negative pressure system and controlling method thereof the efficiency of drying cylinder secondary steam suction is further enhanced, thereby avoided water pump in the problem of running medium speed frequent variations and sprayed in hydrophone because negative pressure constantly changes the damage that it is caused.
For achieving the above object, the present invention has adopted following technological scheme:
Liquid vapour jet-type is taken out a 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 further improves and is: on described water pump, be provided with for regulating the Frequency Converter Control of pump rotary speed.
The present invention further improves and is: described frequency variator adopts the adjustable sublevel PID of parameter controller.
The present invention further improves and is: between the entrance of drying cylinder and outlet, be provided with differential pressure transmitter, the output terminal of differential pressure transmitter is connected with frequency variator by regulator.
The present invention further improves and is: between the outlet of described flash drum and the gas access of water ejector, be provided with the safety check that prevents secondary steam suck-back.
Another object of the present invention, the controlling method that a kind of liquid vapour jet-type is taken out negative pressure system, the differential pressure signal that drying cylinder two ends are set 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, output control signal u controls the output frequency of frequency variator, and then realize the rotating speed of water pump is controlled, the water that water pump sprays water tank with the speed suction of setting reaches the pressure that controls injection hydrophone, realizes this and takes out negative pressure system suction secondary steam.
The present invention further improves and is: the differential pressure of setting drying cylinder two ends is P, and the actual differential pressure when the drying cylinder two ends that record is P
1if, 0 < P
1during≤P/2, sublevel PID regulator is according to the deviate e of input
1adjust parameter, output 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 that record is P
1if, P/2 < P
1during≤P, sublevel PID regulator is according to the deviate e of input
2adjust parameter, output 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 that record is P
1if, P < P
1during≤3/2P, sublevel PID regulator is according to the deviate e of input
3adjust parameter, output 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 that record is P
1if, 3/2P < P
1during≤2P, sublevel PID regulator is according to the deviate e of input
4adjust parameter, output 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 that record is identical with its setting value, sublevel PID regulator is controlled the output frequency of frequency variator with control signal on last stage, and pump rotary speed is with identical on last stage, wherein, and 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 the adjustable sublevel PID of control loop and parameter controller, realized the high problem of water injection device reliability, the efficiency that secondary steam is discharged has obtained further raising, and has avoided water pump to cause its fatigue damage and water ejector because pressure constantly changes the excessive problem of its negative pressure that causes 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 is taken out negative pressure system;
Fig. 2 is the fundamental diagram that a kind of liquid vapour of the present invention jet-type is taken 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 is taken 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 with the liquid inlet of water ejector 1 by water pump 8.On water pump 8, be provided with for regulating the frequency variator of water pump 8 rotating speeds, this frequency variator adopts the adjustable sublevel PID of parameter controller to control.Between the entrance of drying cylinder 5 and outlet, be provided with differential pressure transmitter 4, 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 is taken 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 and sprays water tank 7, then by water pump 8, delivered to again the liquid inlet of water ejector 1, cause water ejector 1 pressure lower than the pressure that is 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 from 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 is controlled the output of frequency variator by receiving drying cylinder 5 two ends differential pressures and the difference of setting differential pressure signal, and then control the rotating speed of jet pump 8, thereby by the flow that 7 li of water of injection water tank are aspirated in adjustings, change the aspiration of secondary steam.
Referring to Fig. 2, the controlling method that a kind of liquid vapour of the present invention jet-type is taken out negative pressure system is as follows, the differential pressure signal that drying cylinder 5 two ends are set 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, output control signal u controls the output frequency of frequency variator, and then realize the rotating speed of water pump 8 is controlled, the water that water pump 8 sprays water tank 7 with the speed suction of setting reaches the pressure that controls injection hydrophone 1, realizes this and takes out negative pressure system suction secondary steam.
Referring to Fig. 3, the controlling method that a kind of liquid vapour of the present invention jet-type is taken out negative pressure system, the differential pressure of setting drying cylinder 5 two ends is P, the actual differential pressure when drying cylinder 5 two ends that record is P
1if, 0 < P
1during≤P/2, sublevel PID regulator is according to the deviate e of input
1adjust parameter, output control signal u
1control the output frequency of frequency variator, and then control water pump 8 rotating speeds are v
1;
Actual differential pressure when drying cylinder 5 two ends that record is P
1if, P/2 < P
1during≤P, sublevel PID regulator is according to the deviate e of input
2adjust parameter, output control signal u
2control the output frequency of frequency variator, and then control water pump 8 rotating speeds are reduced to v
2;
Actual differential pressure when drying cylinder 5 two ends that record is P
1if, P < P
1during≤3/2P, sublevel PID regulator is according to the deviate e of input
3adjust parameter, output control signal u
3control the output frequency of frequency variator, and then control water pump 8 rotating speeds are reduced to speed v
3;
Actual differential pressure when drying cylinder 5 two ends that record is P
1if, 3/2P < P
1during≤2P, sublevel PID regulator is according to the deviate e of input
4adjust parameter, output control signal u
4control the output frequency of frequency variator, and then control water pump 8 rotating speeds are reduced to speed v
4;
When the actual differential pressure at drying cylinder 5 two ends that record is identical with its setting value, sublevel PID regulator is controlled the output frequency of frequency variator with control signal on last stage, and water pump 8 rotating speeds are with identical on last stage, wherein, and 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 under different conditions and the difference of its setting value, 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 is taken out negative pressure system and controlling method thereof is:
The electrical signal that the differential pressure transmitter 4 that the import and export of drying cylinder 5 are installed changes differential pressure is delivered to controller, according to the deviation size of the differential pressure setpoint at drying cylinder 5 two ends and differential pressure measurement value, according to the sublevel PID certainly setting, control principle, from the on-the-spot practical operation situation of motion tracking, control the output frequency of frequency variator, thereby control water pump 8 and deliver to the liquid inlet of water ejector 1 with the water of 7 li, different speed suction injection water tank, and then adjust the pressure of water ejector 1.Under the effect of certain pressure intensity, the water flowing out from water ejector 1 outlet is transformed into kinetic energy potential energy, form high-speed jet, in outlet port, form parital vacuum, caused its pressure lower than the pressure of the body that drawn 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 is transformed into potential energy and is discharged from outside water ejector 1, making it reach the object of suction secondary steam.
Claims (7)
1. liquid vapour jet-type is taken 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 with the liquid inlet of water ejector (1) by water pump (8).
2. liquid vapour jet-type according to claim 1 is taken out negative pressure system, it is characterized in that: on described water pump (8), be provided with for regulating the frequency variator of water pump (8) rotating speed.
3. liquid vapour jet-type according to claim 2 is taken out negative pressure system, it is characterized in that: described frequency variator adopts the adjustable sublevel PID of parameter controller to control.
4. according to the liquid vapour jet-type described in claim 2 or 3, take out negative pressure system, it is characterized in that: between the entrance of drying cylinder (5) and outlet, be provided with differential pressure transmitter (4), the output terminal of differential pressure transmitter (4) is connected with frequency variator by regulator (3).
5. liquid vapour jet-type according to claim 1 is taken out negative pressure system, it is characterized in that: between the outlet of described flash drum (6) and the gas access of water ejector (1), be provided with the safety check (2) that prevents secondary steam suck-back.
6. the controlling method that liquid vapour jet-type according to claim 4 is taken out negative pressure system, it is characterized in that: the differential pressure signal that drying cylinder (5) two ends are set 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, output control signal u controls the output frequency of frequency variator, and then realize the rotating speed of water pump (8) is controlled, the water that water pump (8) sprays water tank (7) with the speed suction of setting reaches the pressure that controls injection hydrophone (1), realize this and take out negative pressure system suction secondary steam.
7. the controlling method that liquid vapour jet-type according to claim 6 is taken out negative pressure system, is characterized in that: the differential pressure of setting drying cylinder (5) two ends is P, and the actual differential pressure when the drying cylinder recording (5) two ends is P
1if, 0 < P
1during≤P/2, sublevel PID regulator is according to the deviate e of input
1adjust parameter, output 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 recording (5) two ends is P
1if, P/2 < P
1during≤P, sublevel PID regulator is according to the deviate e of input
2adjust parameter, output 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 recording (5) two ends is P
1if, P < P
1during≤3/2P, sublevel PID regulator is according to the deviate e of input
3adjust parameter, output 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 recording (5) two ends is P
1if, 3/2P < P
1during≤2P, sublevel PID regulator is according to the deviate e of input
4adjust parameter, output 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 recording (5) two ends is identical with its setting value, sublevel PID regulator is controlled 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.
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| 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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| 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 true CN103644090A (en) | 2014-03-19 |
| CN103644090B CN103644090B (en) | 2016-04-06 |
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|---|---|---|---|
| CN201310631928.5A Active 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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| Country | Link |
|---|---|
| CN (1) | CN103644090B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104264525A (en) * | 2014-09-24 | 2015-01-07 | 陕西科技大学 | Automatic early-warning and elimination system for water accumulation in drying cylinder of paper machine, 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 |
| CN109078350A (en) * | 2018-09-11 | 2018-12-25 | 山东禹王生态食业有限公司 | A kind of food vacuum flash system |
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| 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 |
| 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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2013
- 2013-11-28 CN CN201310631928.5A patent/CN103644090B/en active Active
Patent Citations (6)
| 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 |
| 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 |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104264525A (en) * | 2014-09-24 | 2015-01-07 | 陕西科技大学 | Automatic early-warning and elimination system for water accumulation in drying cylinder of paper machine, 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 |
| CN109078350A (en) * | 2018-09-11 | 2018-12-25 | 山东禹王生态食业有限公司 | A kind of food vacuum flash system |
| 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 |
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| Publication number | Publication date |
|---|---|
| CN103644090B (en) | 2016-04-06 |
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