CN109578114B - Method for controlling overfeeding to urea injector - Google Patents
Method for controlling overfeeding to urea injector Download PDFInfo
- Publication number
- CN109578114B CN109578114B CN201811137626.1A CN201811137626A CN109578114B CN 109578114 B CN109578114 B CN 109578114B CN 201811137626 A CN201811137626 A CN 201811137626A CN 109578114 B CN109578114 B CN 109578114B
- Authority
- CN
- China
- Prior art keywords
- pressure
- supply pump
- urea
- urea supply
- required pressure
- 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.)
- Active
Links
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 title claims abstract description 101
- 239000004202 carbamide Substances 0.000 title claims abstract description 101
- 238000000034 method Methods 0.000 title claims abstract description 16
- 230000000750 progressive effect Effects 0.000 claims description 6
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
- F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N9/00—Electrical control of exhaust gas treating apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
- F01N2610/1433—Pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
- F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
- F01N2610/146—Control thereof, e.g. control of injectors or injection valves
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Abstract
The present invention relates to a method for controlling over-supply to a urea injector, and more particularly, to a method for controlling over-supply to a urea injector, which includes the steps of: a urea supply module operating a urea supply pump at a required pressure at a urea supply pump speed; the DCU records the one second average pressure of the urea supply pump and records the current motor speed; the DCU confirms whether the required pressure of the urea supply pump and the average pressure of the urea supply pump in one second are the same or not so as to confirm whether the required pressure is met or not; if the required pressure is not satisfied, the DCU reconfirms whether the outlet pressure of the urea supply pump is higher than the required pressure; the DCU judges that the required pressure is not reached under the condition that the outlet pressure of the urea supply pump is lower than the required pressure; the DCU determines that the required pressure is exceeded when the outlet pressure of the urea supply pump is determined to be higher than the required pressure.
Description
Technical Field
The present invention relates TO a METHOD for controlling overfeeding from a UREA PUMP TO a UREA INJECTOR (CONTROL METHOD OF UREA PUMP OVERFLOW SUPPLY TO UREA INJECTOR), and more particularly, TO a METHOD for controlling overfeeding TO a UREA INJECTOR, comprising the steps OF: a urea supply module operating a urea supply pump at a required pressure at a urea supply pump speed; a DCU (Dosing control unit) records the one second average pressure of the urea supply pump and records the current motor speed; the DCU confirms whether the required pressure of the urea supply pump and the average pressure of the urea supply pump in one second are the same or not so as to confirm whether the required pressure is met or not; if the required pressure is not satisfied, the DCU reconfirms whether the outlet pressure of the urea supply pump is higher than the required pressure; the DCU judges that the required pressure is not reached under the condition that the outlet pressure of the urea supply pump is lower than the required pressure; the DCU determines that the required pressure is exceeded when the outlet pressure of the urea supply pump is determined to be higher than the required pressure.
Background
Looking at the urea pump pressure control logic applied to the urea injector according to the prior invention, operation of the pump S101 is initiated for the supply of urea.
And, if the required pressure is satisfied S102, the operation of the pump is stopped S109, and if not, it is confirmed whether "outlet pressure of the pump > required pressure" S103.
Then, the driving speed of the pump is increased when the required pressure is not reached S104 and S105, and the driving speed of the pump is decreased when the required pressure is exceeded S106 and S107.
Then, if a drive stop signal S108 is transmitted from the control unit, the drive of the pump is stopped (RPM is 0) S109.
However, the above-described conventional invention cannot utilize the average pressure of the urea supply pump and the current motor speed, and therefore cannot calculate the pressure change rate over the past time and reflect the pressure change rate on the urea supply pump driving speed, and cannot easily control the increase and decrease of the pump driving speed in accordance with the required pressure.
[ Prior art documents ]
[ patent document ]
Korean registered patent No. 1770376
Korean registered patent No. 1405210
Korean registered patent No. 1655201
Disclosure of Invention
The present invention has been made to solve the above problems, and an object of the present invention is to provide a method of controlling an over-supply to a urea injector, which can calculate a pressure change rate in the past time using an average pressure of a urea supply pump applied to the urea injector and a current motor speed, and can reflect the pressure change rate in the past time on a driving speed of the urea supply pump.
To solve the above problem, the present invention relates to a method for controlling an overfeed to a urea injector, comprising the steps of: urea supply module and method
Operating the urea supply pump at a urea supply pump speed; DCU records one second of the urea supply pump
And recording the current motor speed; said DCU identifying the urea supply pump
And one second of the urea supply pump
Whether or not they are the same
Thereby confirming whether the required pressure is satisfied; in the case where the required pressure is not satisfied, the DCU reconfirms whether the outlet pressure of the urea supply pump is higher than the required pressure
The DCU judges that the required pressure is not reached under the condition that the outlet pressure of the urea supply pump is lower than the required pressure; the DCU determines that the required pressure is exceeded when the outlet pressure of the urea supply pump is determined to be higher than the required pressure.
In order to calculate the pressure change rate in the past time by the DCU and reflect the pressure change rate in the past time to the driving speed of the urea supply pump, the method further comprises the steps of: confirming whether the pressure change rate is gradually below a certain value in the past time; the DCU calculates the pressure change rate and reflects it to the driving speed of the urea supply pump; the DCU increases the drive speed of the urea supply pump.
The driving speed of the urea supply pump is increased to the current motor speed (100rpm ·), α is 1 when the pressure change rate (gradual) is equal to or less than a certain value, and 0.2< α <0.8 when the pressure change rate (not gradual) is not gradual.
Further comprising the steps of: the DCU confirming whether the rate of pressure change is gradual over the past time; the DCU calculates a pressure change rate and reflects the pressure change rate to a driving speed of the urea supply pump; the DCU causes the driving speed of the urea supply pump to be reduced; if the DCU transmits a drive stop signal S213 of the urea supply pump, the urea supply pump stops driving.
The driving speed of the urea supply pump is reduced to the current motor speed — (100rpm ×, α), α is 1 when the pressure change rate becomes a constant value or less, and 0.2< α <0.8 when the pressure change rate is not gradual.
The present invention as described above can control the increase and decrease of the pump drive speed by calculating the pressure change rate over the past time and reflecting the pressure change rate on the drive speed of the urea supply pump.
Drawings
FIG. 1 is a diagram representing a urea pump pressure control logic according to the prior art.
FIG. 2 is a flow chart illustrating the sequence of one embodiment of the present invention.
FIG. 3 is a flow chart illustrating a sequence of one embodiment of the present invention.
Detailed Description
For a fuller understanding of the invention, preferred embodiments of the invention are described with reference to the accompanying drawings. The embodiments of the present invention may be modified into various forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below. This example is provided to more fully illustrate the invention to those having ordinary skill in the art. Therefore, the shapes of the elements in the drawings may be exaggerated for the sake of emphasis and clarity. It should be noted that like parts are shown with like reference numerals throughout the several views. In addition, detailed descriptions of well-known functions and configurations determined to unnecessarily obscure the gist of the present invention will be omitted.
In the urea pump pressure control system applied to the urea injector according to the present invention, the urea supply module includes a urea supply pump, a DCU, a pressure sensor, and the like.
A urea supply pump asPumps for supplying urea, by DCU as required
Operating at a certain pump speed.
The pressure sensor measures the requested pressure and causes the DCU to determine whether the urea supply pump is operating at a certain pump speed in order to meet the requested pressure.
The DCU confirms whether the required pressure is met and records the average pressure. In other words, it can be determined whether the required pressure is not reached or exceeded by the information transmitted from the pressure sensor.
In addition, the DCU calculates the pressure change rate and can reflect the pump driving speed.
A method for implementing the present invention using a urea pump pressure control system will be described below.
Urea supply module and method
The urea supply pump S201 is operated at a certain urea supply pump speed.
Recording one second of the urea supply pump
The current motor speed is recorded S202.
For identifying the urea supply pump
And one second of the urea supply pump
Whether or not they are the same
Thereby confirming whether the required pressure S203 is satisfied.
If the condition of step S203 is not satisfied, it is checked again whether or not the outlet pressure of the urea supply pump is higher than the required pressure
S204。
When the DCU judges that the outlet pressure of the urea supply pump is lower than the required pressure, the DCU judges that the required pressure is not reached
S205。
When the outlet pressure of the urea supply pump is higher than the required pressure, it is determined that the required pressure is exceeded
S206。
The DCU checks whether the pressure change rate in the past time is gradual or not in order to calculate the pressure change rate in the past time and reflect the pressure change rate in the drive speed of the urea supply pump S207.
At this time, the pressure change rate in the past time means that the urea supply module is started in S201
The average pressure of the urea supply pump recorded every second while the urea supply pump is operated at a constant urea supply pump speed is recorded every second, so that the taper rate (taper rate) of the pressure change rate can be grasped. The taper is a degree of continuous increase or decrease in the slope of the pressure change rate, and is determined to be not gradual if the change is made rapidly above a predetermined value, or gradual if the change is made below a predetermined value. The specific values may vary depending on experimental conditions.
The DCU calculates the pressure change rate and reflects the calculated taper angle α to the drive speed of the urea supply pump S208.
The DCU increases the driving speed of the urea supply pump S211.
When the current motor speed is (c + (100 rpm) α), α becomes 1 in the progressive case and 0.2< α <0.8 in the non-progressive case.
The DCU confirms whether the rate of pressure change is gradual over the past time S209.
At this time, the pressure change rate in the past time means that the urea supply module is started in S201
The average pressure of the urea supply pump recorded every second while the urea supply pump is operated at a constant urea supply pump speed is recorded every second, so that the taper of the pressure change rate can be grasped. The taper is a degree of continuous increase or decrease in the slope of the pressure change rate, and is determined to be not gradual if the change is made rapidly above a predetermined value, or gradual if the change is made below a predetermined value. The specific values may vary depending on experimental conditions.
The DCU calculates the pressure change rate and reflects the calculated taper angle α on the drive speed S210 of the urea supply pump.
The DCU causes the driving speed of the urea supply pump to decrease S212.
When the current motor speed is (100rpm α), α is 1 in the progressive case and 0.2< α <0.8 in the non-progressive case.
If the DCU transmits the drive stop signal S213 of the urea supply pump, the drive of the urea supply pump is stopped (RPM is 0) S214.
Claims (2)
1. A method of controlling an over-supply to a urea injector as a method of controlling an over-supply to a urea injector by a DCU, comprising the steps of:
operating the urea supply pump according to the required pressure;
the DCU records the average pressure of a certain time period of the urea supply pump and the current motor speed;
confirming whether the required pressure and the average pressure are the same;
confirming whether the outlet pressure of the urea supply pump is higher than the required pressure or not under the condition that the required pressure and the average pressure are different;
when the outlet pressure of the urea supply pump is lower than the required pressure, it is determined that the required pressure is not reached,
determining that the required pressure is exceeded when the outlet pressure of the urea supply pump is higher than the required pressure;
calculating the pressure change rate in the past time and judging the taper alpha;
reflecting the calculated taper of the pressure change rate on the increase or decrease of the driving speed of the urea supply pump;
in the case where it is determined that the required pressure is not reached,
the driving speed of the urea supply pump is increased to the current motor speed + (100rpm a),
when the taper of the pressure change rate is gradually decreased to a certain value, alpha is 1,
0.2< α <0.8 in the non-progressive case;
in the case where it is determined that the required pressure is exceeded,
the driving speed of the urea feed pump is reduced to the current motor speed- (100rpm a),
the case where the taper of the pressure change rate is gradual at a constant value or less is 1,
non-progressive case 0.2< α < 0.8.
2. The method of controlling overfeeding to a urea injector of claim 1,
after the drive speed of the urea supply pump is increased or decreased, the step of confirming whether the required pressure and the average pressure are the same is performed again.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10-2017-0126571 | 2017-09-28 | ||
| KR1020170126571A KR101968318B1 (en) | 2017-09-28 | 2017-09-28 | Control method of urea pump overflow supply to urea injector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109578114A CN109578114A (en) | 2019-04-05 |
| CN109578114B true CN109578114B (en) | 2021-04-27 |
Family
ID=65919913
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811137626.1A Active CN109578114B (en) | 2017-09-28 | 2018-09-28 | Method for controlling overfeeding to urea injector |
Country Status (2)
| Country | Link |
|---|---|
| KR (1) | KR101968318B1 (en) |
| CN (1) | CN109578114B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201013431Y (en) * | 2007-02-12 | 2008-01-30 | 潍柴动力股份有限公司 | SCR post-treating apparatus for high fluid rate engine |
| CN101713317A (en) * | 2009-11-12 | 2010-05-26 | 无锡市凯龙汽车设备制造有限公司 | Method for controlling addition amount of diesel engine tail gas selective catalytic reducing agent |
| CN102155279A (en) * | 2011-04-19 | 2011-08-17 | 潍柴动力股份有限公司 | Device and method for controlling urea injection system of diesel engine |
| CN103046989A (en) * | 2012-12-11 | 2013-04-17 | 潍柴动力股份有限公司 | Plug-and-play urea spraying control method and system |
| KR101723754B1 (en) * | 2015-12-30 | 2017-04-18 | 쌍용자동차 주식회사 | Remain urea removal apparatus of urea line in the diesel vehicle and method thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101405210B1 (en) | 2012-11-08 | 2014-06-27 | 현대자동차 주식회사 | Urea solution pump unit |
| KR101438630B1 (en) | 2013-04-15 | 2014-09-05 | 현대자동차 주식회사 | Method for preventing choking of urea injectiion nozzle on scr system |
| KR101491352B1 (en) | 2013-11-22 | 2015-02-06 | 현대자동차주식회사 | Device and method for test of SCR system in vehicle |
| JP6222168B2 (en) | 2014-06-12 | 2017-11-01 | トヨタ自動車株式会社 | Urea water supply system |
| JP2016011621A (en) * | 2014-06-27 | 2016-01-21 | トヨタ自動車株式会社 | Internal combustion engine reducer supply device |
| KR101655201B1 (en) | 2015-03-09 | 2016-09-07 | 현대자동차 주식회사 | Urea solution pump unit |
| KR101770376B1 (en) | 2016-09-21 | 2017-09-05 | 주식회사 코아비스 | Urea solution pump module |
-
2017
- 2017-09-28 KR KR1020170126571A patent/KR101968318B1/en active IP Right Grant
-
2018
- 2018-09-28 CN CN201811137626.1A patent/CN109578114B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201013431Y (en) * | 2007-02-12 | 2008-01-30 | 潍柴动力股份有限公司 | SCR post-treating apparatus for high fluid rate engine |
| CN101713317A (en) * | 2009-11-12 | 2010-05-26 | 无锡市凯龙汽车设备制造有限公司 | Method for controlling addition amount of diesel engine tail gas selective catalytic reducing agent |
| CN102155279A (en) * | 2011-04-19 | 2011-08-17 | 潍柴动力股份有限公司 | Device and method for controlling urea injection system of diesel engine |
| CN103046989A (en) * | 2012-12-11 | 2013-04-17 | 潍柴动力股份有限公司 | Plug-and-play urea spraying control method and system |
| KR101723754B1 (en) * | 2015-12-30 | 2017-04-18 | 쌍용자동차 주식회사 | Remain urea removal apparatus of urea line in the diesel vehicle and method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20190037007A (en) | 2019-04-05 |
| CN109578114A (en) | 2019-04-05 |
| KR101968318B1 (en) | 2019-08-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9382903B2 (en) | Method and apparatus for optimizing energy efficiency of pumping system | |
| JP6581626B2 (en) | Water supply equipment | |
| US10048701B2 (en) | Dynamic linear control methods and apparatus for variable speed pump control | |
| CN109578114B (en) | Method for controlling overfeeding to urea injector | |
| US10308253B2 (en) | Vehicle lock-up control method and control device | |
| KR20190130025A (en) | Creep Speed Control Method, Apparatus, Vehicle and Computer-readable Media | |
| KR102192509B1 (en) | Apparatus and method for stabilizing an electronic oil pump | |
| JP5052640B2 (en) | Power steering device | |
| EP2294319B1 (en) | Hydraulic device control | |
| JP2006199095A (en) | Compressed air feeder and compressed air feeding method | |
| EP1794432B1 (en) | Fuel pressure control in a common rail system | |
| CA2935762C (en) | Variable speed multi-pump application for providing energy saving by calculating and compensating for friction loss using speed reference | |
| CN106870226B (en) | Method and system for controlling motor of fuel pump | |
| TW201124630A (en) | Hydraulic device | |
| JP4802529B2 (en) | ELECTRIC LIQUID PUMP, CONTROL METHOD AND CONTROL DEVICE THEREOF | |
| US11215151B2 (en) | Emergency operation method for actuating a fuel pump | |
| US20190353170A1 (en) | Method of starting a fan using an open loop starting stage with a decreasing drive signal value | |
| CA3021365A1 (en) | Water distribution network | |
| SE536262C2 (en) | Control device, and method in conjunction with a control device, for controlling a visco coupling | |
| US20220356882A1 (en) | Method of starting a fan using an open loop starting stage with a decreasing drive signal value | |
| JP2007327368A (en) | Pump drought protection device for automatic water supply device | |
| KR20210110954A (en) | Driving control system and method for multi-water pump | |
| JP4675057B2 (en) | Operation control method for centrifugal pump | |
| CN106033252B (en) | Three-way handshake method and computer readable medium | |
| JPH10299663A (en) | Water supply device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |