CN111798656A - Signal transmission system for underground working condition monitoring of electric submersible pump - Google Patents
Signal transmission system for underground working condition monitoring of electric submersible pump Download PDFInfo
- Publication number
- CN111798656A CN111798656A CN202010692257.3A CN202010692257A CN111798656A CN 111798656 A CN111798656 A CN 111798656A CN 202010692257 A CN202010692257 A CN 202010692257A CN 111798656 A CN111798656 A CN 111798656A
- Authority
- CN
- China
- Prior art keywords
- module
- underground
- data
- data signal
- ground
- 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.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C19/00—Electric signal transmission systems
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
-
- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C19/00—Electric signal transmission systems
- G08C19/02—Electric signal transmission systems in which the signal transmitted is magnitude of current or voltage
Abstract
The invention discloses a signal transmission system for monitoring underground working conditions of an electric submersible pump, which comprises an underground data signal transmission module and a ground data signal receiving module; the ground data signal receiving module is connected with the oil well power supply cable through a ground three-phase reactor by adopting a star point connection method; the underground data signal transmission module is connected with a motor winding of an electric submersible pump connected with an oil well power supply cable, the underground data signal transmission module is used for completing data measurement and acquisition and data transmission, and the ground data signal receiving module is used for completing data receiving, data display and storage and remote communication; the underground data transmission module generates time-varying high and low currents influenced by the measurement parameter values, and the surface data signal receiving module analyzes the currents to obtain a transmission result.
Description
Technical Field
The invention relates to the field of signal transmission for underground working condition monitoring, in particular to a signal transmission system for underground working condition monitoring of an electric submersible pump.
Background
Along with the oil exploitation enters the middle and later stages, shallow layer oil resources are gradually exhausted, oil wells are deeper and deeper, the well temperature is higher and higher, the well pressure is lower and lower, and a large number of inclined wells and horizontal wells appear, so that the oil extraction by the traditional self-injection method becomes more and more difficult under the situation. In order to solve the problems, the electric submersible pump is widely applied to high-yield oil wells, high-water-cut wells, deep wells, directional wells and horizontal wells after blowout is stopped by virtue of the advantages of high efficiency, large discharge capacity, high lift and the like, but the electric submersible pump works below thousands of meters away from the ground and has the characteristic of long-term working.
The underground distance of several kilometers from the ground is reserved in the submersible electric pump well, underground signal transmission to the ground is needed to monitor the working condition of the submersible electric pump, and the influence of long-distance transmission and large interference noise on the signal transmission generally causes poor domestic use conditions.
The current loop communication mode utilizes current to transmit signals, has strong anti-interference capability, has high reliability on an industrial site with a complex noise environment, has long transmission distance and has great advantages in the transmission process of the submersible electric pump well with the oil of thousands of meters. However, the signal transmission mode has high requirement on the measurement accuracy of the reference working current, and if the measurement of the reference current has overlarge deviation, the problem of inaccurate information transmission exists.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a signal transmission system for underground working condition monitoring.
The purpose of the invention is realized by the following technical scheme:
a signal transmission system for underground working condition monitoring of an electric submersible pump comprises an underground data signal transmission module and a ground data signal receiving module; the ground data signal receiving module is connected with the oil well power supply cable through a ground three-phase reactor by adopting a star point connection method; the underground data signal transmission module is connected with a motor winding of an electric submersible pump connected with an oil well power supply cable, the underground data signal transmission module is used for completing data measurement and acquisition and data transmission, and the ground data signal receiving module is used for completing data receiving, data display and storage and remote communication; the underground data transmission module generates time-varying high and low currents influenced by the measurement parameter values, and the surface data signal receiving module analyzes the currents to obtain a transmission result.
Further, the underground data signal transmission module comprises an underground sensor module, an underground single chip microcomputer, a digital-to-analog conversion circuit, a voltage-current conversion circuit and an underground power supply module; the underground power supply module supplies power to the underground sensor module, the underground singlechip, the digital-to-analog conversion circuit and the voltage-current conversion circuit; the underground sensor module receives data and inputs the data into the underground singlechip through a serial port, the underground singlechip performs fixed sequencing on the data to be transmitted to output high-low pulse waves with high-level pulse width and data value having a fixed functional relation, outputs voltage signals through the digital-to-analog conversion circuit, outputs current signals through the voltage-current conversion circuit, performs remote transmission in a current loop communication mode, and transmits the current signals to the ground data signal receiving module for signal processing.
Furthermore, the ground data signal receiving module comprises a current-voltage conversion circuit, a multi-stage amplification circuit, a comparator, an aboveground singlechip, a display module and an aboveground power supply module; the ground power supply module supplies power to the current-voltage conversion circuit, the multi-stage amplification circuit, the comparator, the ground singlechip and the display module, and simultaneously generates a direct current power supply at the star point connection position to supply power to the underground data signal transmission module; the current signal transmitted in the current loop communication mode is output as a voltage signal by the current-voltage conversion circuit, enters the comparator through the multistage amplification circuit, is compared with a given threshold voltage to output high and low pulse waves, and is input into the aboveground singlechip, and the aboveground singlechip performs data processing and then performs data display through the display module.
Furthermore, a choke is arranged between the underground data signal transmission module and the oil well power supply cable; and a ground three-phase reactor is arranged between the ground data signal receiving module and the oil well power supply cable.
Further, the sensor module is composed of a pressure sensor, a temperature sensor and a vibration sensor. Further, the sensor module is composed of a pressure sensor, a temperature sensor and a vibration sensor.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
1. the invention adopts a star point power supply method and a current loop signal transmission mode, the star point power supply method can meet the power supply required by underground signal acquisition and transmission only depending on the original motor power supply cable of the submersible electric pump well without additionally laying a cable, the installation cost and the installation difficulty of the underground working condition monitoring system of the submersible electric pump are greatly reduced, meanwhile, the current signal is utilized for transmission in the remote transmission process, the current loop communication mode is adopted for transmitting the signal, the anti-interference capability is strong, the transmission distance is long, and the transmission and extraction difficulty of the test signal can be reduced.
2. The invention adopts a transmission mode of representing the information of the measurement parameter by the high and low current time width of the current signal. In a common current loop communication mode, the measurement accuracy of the reference current is high, and different underground environments have different influences on the reference current value, and the influences cause uncertainty in data transmission. The invention adopts the transmission mode that the time width of high and low currents of the current signal represents the information of the measurement parameter, can only compare the magnitude of the current without particularly accurately measuring the reference current, not only reduces the working difficulty, but also improves the accuracy of data transmission.
3. The invention can monitor the unit working condition of the submersible electric pump by measuring six parameters of pump outlet pressure, pump inlet temperature, motor winding temperature, unit horizontal vibration and unit vertical vibration, can stop loss in time when abnormality occurs, can adjust and control the output power of the submersible electric pump according to the measurement result, ensures that the submersible electric pump always runs in a high-efficiency area, and improves the productivity and efficiency of an oil well.
Drawings
Fig. 1 is a schematic structural diagram of a signal transmission system for monitoring the underground working condition of the submersible electric pump.
Fig. 2 is a schematic diagram of an insulation voltage test circuit of the transmission system.
Fig. 3 is a waveform diagram of a transmission current signal of the transmission system.
Detailed Description
The invention is described in further detail below with reference to the figures and specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 1, the signal transmission system for monitoring the downhole working condition of the submersible electric pump comprises a downhole data signal transmission module and a ground data signal receiving module.
The ground data signal receiving module is connected with the oil well power supply cable through a ground three-phase reactor by adopting a star point connection method; the underground data signal transmission module is connected with a motor winding of an electric submersible pump connected with an oil well power supply cable, the underground data signal transmission module generates high and low currents which are influenced by measurement parameter values and change along with time, and the ground data signal receiving module analyzes the currents to obtain a transmission result.
The ground data signal receiving module in the signal transmission system comprises a current-voltage conversion circuit, a multi-stage amplification circuit, a comparator, an aboveground singlechip, a display module and an aboveground power supply module. The ground data signal receiving module needs to complete data receiving, data displaying and data remote transmission. The on-ground power supply module is connected with a 220V alternating current power supply, the 220V alternating current power supply is converted into a direct current power supply through the on-ground power supply module and provides power required by work for the current-voltage conversion circuit, the multistage amplification circuit, the comparator, the on-ground single chip microcomputer and the display module.
The underground data signal transmission module in the signal transmission system comprises an underground power circuit, an underground sensor module, an underground single chip microcomputer, a digital-to-analog conversion circuit and a voltage-current conversion circuit. The underground data signal transmission module needs to complete underground environment signal measurement and acquisition and data transmission.
In the specific implementation process, the underground sensor module is used for measuring and collecting data of underground environment information, and the sensor module is composed of a pressure sensor, a temperature sensor and a vibration sensor and is used for measuring six parameters including pump outlet pressure, pump inlet temperature, motor winding temperature, unit horizontal vibration and unit vertical vibration. The underground single-chip microcomputer controls and collects data according to a certain time sequence, a 24-bit AD chip with 8 differential channels is adopted to carry out AD conversion on the data collected by the sensor, the converted data are sent to the underground single-chip microcomputer through a serial port, the underground single-chip microcomputer processes the signals after receiving the signals, the timer is used for fixedly sequencing the data to be sent according to a certain communication protocol and outputting high-level pulse waves with high-level pulse widths having a fixed functional relation with a data value, and a digital-to-analog conversion circuit is used for outputting voltage signals with high-voltage duration having a fixed functional relation with the data value.
In long distance transmission, the low voltage signal generated by the downhole data signal transmission module can be severely attenuated due to the impedance of the transmission line, thereby resulting in insufficient accuracy of the measurement result. In the embodiment, a low-voltage signal generated by a downhole data signal transmission module is converted into a current signal through a voltage-current conversion circuit, and the current loop transmission of analog quantity is realized in the form of the current signal through a submersible power supply cable. And sending the current signal to a ground data signal receiving module in a current loop communication mode.
After the current signal with the data information flows into a ground data signal receiving module, the received current signal is converted into a voltage signal through a current-voltage conversion circuit, the voltage signal is subjected to noise reduction processing through a multistage amplifying circuit and a filter circuit, a ground singlechip carries out self-adaptive adjustment on threshold voltage according to the received voltage signal, so as to avoid the noise generated in the transmission process from causing the subsequent counting to generate misjudgment on the time length of the high level, the comparator circuit compares the threshold voltage with the voltage signal, the on-well singlechip counts the time length of the high level, and obtaining a measured value according to the measured time length, carrying out data one-to-one correspondence on the measured parameters such as pump outlet pressure, pump inlet temperature, motor winding temperature, unit horizontal vibration, unit vertical vibration and the like according to a communication protocol, and carrying out data display through a display module.
The ground data signal receiving module also has the function of measuring leakage current, can monitor whether the current loop communication mode works normally, measures the differential pressure of current signals flowing through a precision resistor through a differential amplifier, and obtains a measuring result by an aboveground singlechip after AD conversion.
And a display module in the ground data signal receiving module is provided with a remote communication port Modbus RS485 so as to realize remote monitoring of the measured data. The display module part also has a data storage function and can realize the export of measurement historical data.
The ground data signal receiving module and the power supply cable provide power supply for the underground data signal transmission module by adopting a star point power supply method. And a power supply cable of the electric submersible pump is utilized to supply direct current power to the underground data signal transmission module according to the star point equipotential power supply principle.
The ground data signal receiving module is connected with a group of star-connected three-phase reactors, an artificial star point is constructed by using the three-phase reactors, direct current voltage is applied through the star point of the three-phase reactors, the other side of the three-phase reactors is respectively connected with three phases of an oil-submersible cable, meanwhile, the oil-submersible motor is also in a star-connected mode, the three-phase star point of the motor is connected with a downhole data signal transmission module, an aboveground power supply module of the ground data signal receiving module is connected with 220V alternating current, AC/DC conversion of electric energy is realized through the aboveground power supply module, alternating current from a power grid is converted into direct current which is applied to a ground three-phase reactance neutral point to generate direct current, the direct current power supply is supplied to the downhole data signal transmission module through an armored cable of three-phase power of the motor, the downhole power supply module adopts a flyback structure, and the downhole data signal transmission module, the power supply of the input end of the underground power supply is realized by utilizing the voltage stabilizing effect of the voltage stabilizing diode of the underground power supply module. And providing a working power supply for each module in the underground data signal module.
The underground data signal transmission module adopts a blocking diode to realize the measurement of the ground insulation of the system, two voltage stabilizing diodes are added at the positive input end of a choke, and a Zener diode is connected in parallel with the input end of an underground circuit at the tail end of the choke. When the submersible motor is used for measuring the insulation value, the negative meter pen of the megohmmeter is connected with the stator, and the positive meter pen of the megohmmeter is connected with the shell for measuring.
As shown in fig. 2, D1 and D2 are blocking diodes GP02-40, D3 is zener diode, and D4 and D5 are two zener diodes.
FIG. 3 is a waveform diagram of a transmission signal of a transmission system, which is a current waveform diagram transmitted by a downhole data signal transmission module and a ground data signal receiving module in a current loop communication manner, during the measurement, six parameters of pump outlet pressure, pump inlet temperature, motor winding temperature, unit horizontal vibration and unit vertical vibration are obtained by the downhole sensor part, after the six parameters are subjected to analog-to-digital conversion by a 24-bit AD chip with 8 differential channels, the measurement result is input into a downhole singlechip via a serial port, the downhole singlechip arranges the six parameters in sequence according to the requirements of a communication protocol after receiving data information, generates time pulses according to a timer, sets a low-level pulse width of 1000ms as an initial signal of a group of data transmission, the high-level part of pulse waves represents the measured parameter values, and in order to avoid the parameters causing the situation that the high-level pulse waves received by the ground data signal receiving module are difficult to detect when the low-level pulse waves are received So that deviation occurs, the shortest high-level pulse width of 1000ms is set (namely when the measurement parameter is 0), in the transmission process, the high-level pulse width of the pulse wave is the sum of 1000ms and the measurement parameter, the low-level pulse width of 750ms is formed between the transmitted measurement parameters, and the next measurement parameter is transmitted after the low-level pulse width of 750ms is detected. After the six measurement parameters are transmitted once, the data transmission is considered to be finished, the underground single chip microcomputer generates the next low-level pulse width of 1000ms, and the next group of data transmission is started.
In the ground data signal receiving module, the singlechip interrupts and monitors the serial port level, when the low level is input, the low level pulse width is counted, if the detected low level pulse width is 1000ms, the data transmission flag bit is met, the high level pulse width is counted, the shortest high level pulse width is subtracted from the counted pulse time width after counting is finished for 1000ms, the rest value is the measured value, and according to the set communication protocol, pump outlet pressure, pump inlet temperature, motor winding temperature, unit horizontal vibration and the measured value of six parameters of unit vertical vibration are respectively obtained. And after data conversion, the data is displayed through a serial port screen in a display module in the ground data signal receiving module.
The present invention is not limited to the above-described embodiments. The foregoing description of the specific embodiments is intended to describe and illustrate the technical solutions of the present invention, and the above specific embodiments are merely illustrative and not restrictive. Those skilled in the art can make many changes and modifications to the invention without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (5)
1. A signal transmission system for monitoring the underground working condition of an electric submersible pump is characterized by comprising an underground data signal transmission module and a ground data signal receiving module; the ground data signal receiving module is connected with the oil well power supply cable through a ground three-phase reactor by adopting a star point connection method; the underground data signal transmission module is connected with a motor winding of an electric submersible pump connected with an oil well power supply cable, the underground data signal transmission module is used for completing data measurement and acquisition and data transmission, and the ground data signal receiving module is used for completing data receiving, data display and storage and remote communication; the underground data transmission module generates time-varying high and low currents influenced by the measurement parameter values, and the surface data signal receiving module analyzes the currents to obtain a transmission result.
2. The signal transmission system for monitoring the downhole working condition of the electrical submersible pump according to claim 1, wherein the downhole data signal transmission module comprises a downhole sensor module, a downhole single chip microcomputer, a digital-to-analog conversion circuit, a voltage-current conversion circuit and a downhole power supply module; the underground power supply module supplies power to the underground sensor module, the underground singlechip, the digital-to-analog conversion circuit and the voltage-current conversion circuit; the underground sensor module receives data and inputs the data into the underground singlechip through a serial port, the underground singlechip performs fixed sequencing on the data to be transmitted to output high-low pulse waves with high-level pulse width and data value having a fixed functional relation, outputs voltage signals through the digital-to-analog conversion circuit, outputs current signals through the voltage-current conversion circuit, performs remote transmission in a current loop communication mode, and transmits the current signals to the ground data signal receiving module for signal processing.
3. The signal transmission system for monitoring the downhole working condition of the electric submersible pump according to claim 1, wherein the ground data signal receiving module comprises a current-voltage conversion circuit, a multi-stage amplifying circuit, a comparator, an aboveground singlechip, a display module and an aboveground power supply module; the ground power supply module supplies power to the current-voltage conversion circuit, the multi-stage amplification circuit, the comparator, the ground singlechip and the display module, and simultaneously generates a direct current power supply at the star point connection position to supply power to the underground data signal transmission module; the current signal transmitted in the current loop communication mode is output as a voltage signal by the current-voltage conversion circuit, enters the comparator through the multistage amplification circuit, is compared with a given threshold voltage to output high and low pulse waves, and is input into the aboveground singlechip, and the aboveground singlechip performs data processing and then performs data display through the display module.
4. The signal transmission system for monitoring the downhole working condition of the electrical submersible pump according to claim 1, wherein a choke is arranged between the downhole data signal transmission module and the oil well power supply cable; and a ground three-phase reactor is arranged between the ground data signal receiving module and the oil well power supply cable.
5. The electrical submersible pump downhole condition monitoring signal transmission system of claim 2, wherein the sensor module comprises a pressure sensor, a temperature sensor, and a vibration sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010692257.3A CN111798656A (en) | 2020-07-17 | 2020-07-17 | Signal transmission system for underground working condition monitoring of electric submersible pump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010692257.3A CN111798656A (en) | 2020-07-17 | 2020-07-17 | Signal transmission system for underground working condition monitoring of electric submersible pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111798656A true CN111798656A (en) | 2020-10-20 |
Family
ID=72807606
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010692257.3A Pending CN111798656A (en) | 2020-07-17 | 2020-07-17 | Signal transmission system for underground working condition monitoring of electric submersible pump |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111798656A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116499500A (en) * | 2023-06-28 | 2023-07-28 | 珠海矽敏科技有限公司 | Sensor system, sensor, signal output circuit of sensor and signal acquisition equipment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202391407U (en) * | 2011-12-07 | 2012-08-22 | 西安思坦仪器股份有限公司 | Tractometer of electric submersible pump |
| CN203783562U (en) * | 2014-01-21 | 2014-08-20 | 中国海洋石油总公司 | Underground multi-parameter monitoring device for electric submersible pump |
| CN107781175A (en) * | 2017-10-23 | 2018-03-09 | 中国石油天然气股份有限公司 | Submersible electric pump same-well injection oil recovery intelligent monitor system |
-
2020
- 2020-07-17 CN CN202010692257.3A patent/CN111798656A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202391407U (en) * | 2011-12-07 | 2012-08-22 | 西安思坦仪器股份有限公司 | Tractometer of electric submersible pump |
| CN203783562U (en) * | 2014-01-21 | 2014-08-20 | 中国海洋石油总公司 | Underground multi-parameter monitoring device for electric submersible pump |
| CN107781175A (en) * | 2017-10-23 | 2018-03-09 | 中国石油天然气股份有限公司 | Submersible electric pump same-well injection oil recovery intelligent monitor system |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116499500A (en) * | 2023-06-28 | 2023-07-28 | 珠海矽敏科技有限公司 | Sensor system, sensor, signal output circuit of sensor and signal acquisition equipment |
| CN116499500B (en) * | 2023-06-28 | 2024-01-30 | 珠海矽敏科技有限公司 | Sensor system, sensor, signal output circuit of sensor and signal acquisition equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN205246764U (en) | Open -phase detecting circuit of polyphase source | |
| CN108227004A (en) | A kind of high density alternating current-direct current swashs electric system and its method of work | |
| CN202391407U (en) | Tractometer of electric submersible pump | |
| CN111798656A (en) | Signal transmission system for underground working condition monitoring of electric submersible pump | |
| CN205100258U (en) | Deep cement stirring pile driving construction data monitoring device | |
| CN102621345A (en) | Detection method and device of rotation speed of generator | |
| CN203261029U (en) | Power grid grounding compensation device based on arc suppression transformer | |
| CN205246806U (en) | Long -range cable on -line measuring system | |
| CN102477862B (en) | Application of detector (for acquiring underground oil-water interfaces) controlled by portable computer | |
| CN113110262A (en) | Well group casing cathode protection remote pressure regulating system and pressure regulating method | |
| CN105652149A (en) | Power cable monitoring and early warning operating system | |
| CN109458170A (en) | Intelligent cluster well remote centralized control system | |
| CN111948488A (en) | Distribution cable fault monitoring system and use method | |
| CN204044250U (en) | A kind of multi-frequency scanning formula pole tower ground resistance measurement mechanism | |
| CN103280793A (en) | Electric network grounding compensation device based on arc suppression transformer | |
| CN113542925A (en) | Transmission system and transmission method for transmitter signal power information | |
| CN110887597A (en) | Two-wire system intelligent differential pressure controller transmitter digital display instrument | |
| CN206258544U (en) | A kind of submarine cable detection means suitable for marine wind electric field | |
| CN202058297U (en) | Cable failure data acquisition and remote transmission system | |
| CN107781175A (en) | Submersible electric pump same-well injection oil recovery intelligent monitor system | |
| CN206888975U (en) | Latent oil reciprocating oil pumping unit level information online acquisition device | |
| CN209748555U (en) | Watertight connector | |
| CN202578675U (en) | Signal transmission system based on power centre line of electric submersible pump | |
| CN204789868U (en) | Distribution cable electricity status monitoring device | |
| CN203054027U (en) | Underground choking flow unit of electrical submersible pump real-time monitoring system |
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 | ||
| CB03 | Change of inventor or designer information | ||
| CB03 | Change of inventor or designer information |
Inventor after: Chen Xiaohan Inventor after: Chen Shili Inventor after: Hu Song Inventor after: Zeng Zhoumo Inventor before: Chen Xiaohan Inventor before: Chen Shili Inventor before: Zeng Zhoumo |
|
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20201020 |