WO2015180522A1

WO2015180522A1 - High-accuracy liquid-level sensor and liquid-level remote-measuring and remote control instrument

Info

Publication number: WO2015180522A1
Application number: PCT/CN2015/073948
Authority: WO
Inventors: 罗湘利; 罗翔
Original assignee: 罗湘利
Priority date: 2014-05-26
Filing date: 2015-03-10
Publication date: 2015-12-03
Also published as: CN104236669A

Abstract

A high-accuracy liquid-level sensor (1), comprising a base (14), a pedestal (15), an intermediate joint (16), a differential pressure sensor (17), a sheath joint (18), a dedicated gas cable sheath (19), a dedicated gas cable (22) and a stainless-steel filter screen sheath (25). A liquid-level remote-measuring and remote control instrument, comprising the high-accuracy liquid-level sensor (1), and also comprising an operation amplifier (2), an A/D convertor (3), an embedded single chip microcomputer (6), an I/O port (7), a membrane keyboard (9), a strong-current executor (10), a GPRS short message transceiver (11) and embedded dedicated control software (13). The measuring range of the high-accuracy liquid-level sensor is 1 mm to 10000 mm, and the resolution thereof is 0.2 mm; and when the measuring range is 1 mm to 5000 mm, the resolution can reach 0.1 mm.

Description

High-precision liquid level sensor and liquid level remote measuring remote controller

Technical field

The invention relates to the field of remote telemetry online instruments, in particular to a liquid level sensor and a high-precision liquid level telemetry remote control instrument based on a mobile phone network.

Background technique

There are many types and specifications of instruments and equipment for detecting and controlling the liquid level. For example, the float switch can control the height range of the liquid level, but the liquid level value cannot be detected. The liquid level control system made of pressure sensor has different atmospheric pressure values due to different calibration or calibration, so that the liquid level sensor has zero point when the liquid level sensor is not placed in the liquid. Big deviation.

It is very important to monitor the liquid level of the water storage type sewage pool, urban underground sewage, rainwater drainage culvert or river. For example, if the culvert is blocked in the city's sewage drainage, the liquid level will rise to form the internal raft. Under the road overpass in the same city, there is almost no automatic monitoring and alarming of the depth of the accumulated water, and there is a passenger car driving into the water to extinguish the fire, resulting in a tragedy. .

The rainfall of the weather station is measured using a graduated glass cylinder, manually observed, and manually recorded. Accuracy and workload are problems, and the continuity of the record and the moment of a moment are difficult to provide the necessary information.

Summary of the invention

The purpose of the invention is to solve the shortcomings of the prior art products that the precision of the existing products is not high, the ability to adapt to various complicated situations is insufficient or not strong, the intelligence is low, the versatility is poor, the telemetry and the remote control cannot be performed, and a high-precision liquid level sensor and A liquid level remote measuring remote control instrument.

A high-precision liquid level sensor comprises a base, a base, a middle joint, a differential pressure sensor, a sheath joint, a special gas cable sheath, a special gas cable, a stainless steel filter net sleeve; the sheath joint and the special gas The cable jacket is connected to the base by a connection to the base, the intermediate joint is connected to the base, and the stainless steel filter sleeve is disposed between the base and the base, the difference The pressure sensor includes a high end and a low end, and the high end liquid level is a lower liquid, an atmospheric pressure above the low-end liquid passing surface, the differential pressure sensor is disposed in the base, the base is provided with a hole for conducting a liquid, and the special gas cable is provided with an air pipe, The low end is connected to the through-tube, and the dedicated gas cable is provided with leads.

As a further improvement of the present invention, the differential pressure sensor is of the type 24CCFA6D.

As a further improvement of the present invention, the liquid-conducting holes of the base are inclined holes, and the liquid-conducting holes of the base are three, four or five.

As a further improvement of the present invention, the base is connected to the base by threads, and the intermediate joint and the base are sealed by an O-ring.

As a further improvement of the present invention, the high end is provided with a liquid pressure sensing film.

A liquid level remote sensing remote control apparatus, comprising the high precision liquid level sensor according to any one of the above, further comprising an operational amplifier, an A/D converter, an embedded single chip microcomputer, an I/O port, a membrane keyboard, a strong electric actuator, GPRS short message transceiver, embedded special control software; the electrical signal of the differential pressure sensor is amplified by the operational amplifier, and then the analog signal is converted into a digital signal by the A/D converter for the embedded single chip microcomputer to perform Processing, the membrane keyboard is used to set parameters, when the liquid level exceeds the high limit, the embedded single-chip microcomputer commands the high-power actuator to turn on the power of the main equipment pump motor, and the liquid level drops, when it falls to the low position. The limited time pump stops working; if the liquid level does not drop when the liquid level is working, the high limit of the standby device setting is higher than the high limit of the main device, and the liquid level reaches the high limit set by the standby device. Sending an alarm request to the GPRS short message transceiver to send a short message and simultaneously turning on the standby device.

As a further improvement of the present invention, the parameters set by the membrane keyboard include a setting of a high-precision liquid level range, a low-limit limit, a high-limit setting, a password setting of a first-level administrator, a mobile phone number setting, and a forced start standby device. parameter settings.

As a further improvement of the present invention, a power source is also included, and all of the units are powered by the power source 4.

As a further improvement of the present invention, including the USB port, the USB port always keeps the latest data according to the advanced and outgoing rules, and the data is saved in the xls format.

As a further improvement of the present invention, a liquid crystal display, a flash memory, and parameters of the membrane keyboard setting are displayed on the liquid crystal display and stored in the flash memory.

The high-precision liquid level sensor of the present invention has a measuring range of 1 to 10000 mm, a resolution of 0.2 mm, and a resolution of 0.1 mm when the range of the range is 1 to 5000 mm.

The high-precision liquid level sensor compares the pressure of different depths of the high-pressure collecting liquid of the differential pressure sensor with the atmospheric pressure of the low end, and can accurately detect and control the liquid level difference of 1 mm or less.

The liquid level remote sensing remote control instrument of the invention has the following obvious effects compared with the prior art:

The liquid level detection accuracy is high, and there are 5,000 complete historical records. It can be used as a professional equipment for the automatic detection of the meteorological department and the water conservancy inspection department, and the liquid level information is provided by the SMS timing.

It is used for liquid level monitoring and alarm of urban municipal drainage culverts or sloping roads, and provides early warning information for internal rafts.

Automatic level control and remote telemetry for sewage treatment plants or separate lagoons.

Automatic water level adjustment is performed on the water tower, automatic alarm of equipment failure is performed, the standby equipment is turned on, and the administrator is notified to handle.

Easy to install and use, cost-effective, reducing manual inspection costs and errors.

DRAWINGS

1 is a schematic diagram showing the principle, information flow and basic structure of a liquid level remote measuring remote control device of the present invention;

2 is a schematic structural view of a high-precision liquid level sensor of the present invention;

3 is a schematic diagram of the liquid level upper limit alarm setting of the liquid level remote measuring remote control device of the present invention;

4 is a schematic diagram of the liquid level lower limit alarm setting of the liquid level remote measuring remote control device of the present invention;

5 is a flow chart of password setting and parameter setting of the liquid level remote measuring remote controller of the present invention;

6 is a schematic diagram of electrical wiring of a liquid level remote sensing remote control instrument of the present invention.

The names of the parts in the figure are as follows:

High-precision liquid level sensor 1, operational amplifier 2, A/D converter 3, power supply 4, liquid crystal display 5, embedded MCU 6, I/O port 7, flash memory 8, membrane keyboard 9, high-voltage actuator 10, GPRS Short message transceiver 11, USB port 12, embedded dedicated control software 13, base 14, base 15, intermediate joint 16, differential pressure sensor 17, sheath joint 18, special gas cable sheath 19, through atmospheric tube 20, lead 21, special gas cable 22, low-end 23, O-ring 24, stainless steel filter net 25, high-end 26.

detailed description

The invention will be further described below in conjunction with the accompanying drawings.

As shown in FIG. 2, FIG. 2 is a schematic structural process diagram of the high-precision liquid level sensor of the present invention, and a high-precision liquid level sensor including a base 14, a base 15, a middle joint 16, a differential pressure sensor 17, and a sheath. a joint 18, a special gas cable jacket 19, a special gas cable 22, a stainless steel filter jacket 25; the jacket joint 18 and the special gas cable jacket 19 are connected to the intermediate joint 16, the base 14 and the The base 15 is connected, the intermediate joint 16 is connected to the base 15, the stainless steel filter sleeve 25 is disposed between the base 15 and the base 14, and the differential pressure sensor 17 includes a high end 26 and a low end. 23, the high-end 26 liquid below the liquid level, the low-end 23 is above the liquid level, the differential pressure sensor 17 is disposed in the base 15, the base 14 is provided with a hole for conducting liquid, The special gas cable 22 is provided with an air duct 20, the low end 23 is connected to the air duct 20, and the special air cable 22 is provided with a lead wire 21.

The high-precision liquid level sensor uses a differential pressure sensor to form a core component, and the differential pressure sensor has a model number of 24CCFA6D. The liquid below the high-end liquid-passing surface of the differential pressure sensor and the atmospheric pressure above the low-pressure liquid-passing surface of the differential pressure sensor. The electric signal of the differential pressure sensor is amplified by 22.2 times by the operational amplifier, and the standard model of 5V is formed into a digital signal by A/D conversion, which is processed by the embedded single chip microcomputer, and all the units are powered by the power source.

The liquid-passing base 14 has four inclined holes for conducting liquid, and the base 14 is connected to the base 15 of the differential pressure sensor 17 by threads. A stainless steel filter sleeve 25 is added between the base 15 and the base 14 for prevention. The moving minute particles in the liquid are in contact with the liquid pressure sensing film of the high end 26 of the differential pressure sensor 17. Differential pressure sensor mounted between intermediate joint 16 and base 15 17 is sealed by an O-ring 24 to prevent the liquid from entering the low end 23 of the differential pressure sensor 17 by the pressure generated by the depth, and the low end 23 communicates with the atmospheric pressure pipe 20 in the special gas cable 22 and the atmospheric pressure above the liquid level to ensure the difference. The liquid depth formed by the liquid pressure generated by the high end 26 of the pressure sensor 17 and the atmospheric pressure generate a differential pressure electrical signal. The electrical signal of the differential pressure sensor 17 is turned on by the four leads 21 in the dedicated gas cable 22. The sheath joint 18 and the waterproof and anticorrosive special gas cable sheath 19 are connected to the intermediate joint 16 by threads, so that the low end 23 of the differential pressure sensor 17 and the special gas cable 22 are subjected to pressure of the liquid and atmospheric pressure without leakage. The base 14, the base 15, the intermediate joint 16, and the sheath joint 18 are all made of stainless steel and have a stainless steel designation of 304. The special gas cable sheath 19 is formed by vulcanization of a silicone rubber mold.

The high-precision level sensor 1 has a measuring range of 1 to 10000 mm and a resolution of 0.2 mm. When the range is from 1 to 5000 mm, the resolution can be 0.1 mm. The operational amplifier 2 amplifies the electric signal of the millivolt level of the high-precision liquid level sensor 1 to 5 V, and the amplification factor is 22.2 times. The amplified standard signal is converted into a digital signal by the A/D converter 3. The A/D converter is 16-bit and has a minimum resolution of 0.078 mm over a 5000 mm range. The power supply 4 obtains various required voltage values and powers through a commercial power exchange 220V switching power supply, and the power supply 4 also includes three-phase four-wire power.

Due to the use of the high-precision liquid level sensor made of differential pressure sensor, the atmospheric pressure above the liquid level is used as the reference reference zero point, and the 16-bit A/D converter is used to make the liquid level detection and control accuracy exceed 1 mm, which solves the traditional pressure. The transmitter does not have the zero point error and low precision and large error caused by the liquid level sensor.

As shown in FIG. 1 , FIG. 1 is a schematic diagram of a block principle, an information flow, and a basic structure of a liquid level remote sensing remote control apparatus according to the present invention. The present invention includes a high-precision liquid level sensor 1, an operational amplifier 2, an A/D converter 3, and a power supply. 4. Liquid crystal display 5, embedded single chip microcomputer 6, I/O port 7, flash memory 8, membrane keyboard 9, strong electric actuator 10, GPRS short message transceiver 11, USB port 12 and embedded special control software 13.

When the operational amplifier 2 and the A/D converter 3 have a water column height within a range of 10 meters, the number of bits of the A/D converter 3 is 16 bits, and the minimum resolution of the detection liquid level is 0.156 mm.

The liquid crystal display 5, the embedded single-chip 6, the I/O port 7, the flash memory 8, the membrane keyboard 9 can set the unit of the high-precision liquid level sensor range and the liquid level height, and the minimum liquid level, that is, the low level limit and the highest liquid level, that is, the high level limit. .

The electric actuator 10 can automatically open or close the water pump or the valve according to the set liquid level parameter. The liquid level is kept within the set safe range. When the main execution device fails, the liquid level is over limit, the standby device automatically starts or the SMS is forced. Startup, the startup parameters of the standby device are set to be stricter than the primary execution device.

The GPRS short message transceiver 11 can receive the short message request of the first and second level administrators, and send the real time value of the liquid level and the history record of the liquid level at that time. The flash memory 8 can store and record 5000 sets of liquid level real-time information and history records, and copy the history records through the U disk.

The embedded dedicated control software 13 includes a main control program, a communication program with the GPRS short message transceiver 11, and a program for digitally filtering the output signals of the high-precision liquid level sensor 1 and the A/D converter 3.

The liquid crystal display 5 in Fig. 1 is used to display the liquid level value in real time. The default unit of the liquid level value is mm, and 5 significant digits, including one decimal place. At the same time, the first three and the last four digits of the mobile phone of the first-level administrator are displayed. Display parameters in the parameter setting process or modify the parameters through the membrane keyboard 9. The membrane keyboard is used to set various parameters, such as the setting of high-precision liquid level range, the setting of low-limit and high-limit, the first-level administrator Password settings, mobile number settings, and parameter settings for forced activation of the alternate device. Various settings and parameters are placed in the flash memory 8 by the embedded microcontroller 6 in accordance with the instructions specified by the embedded dedicated control software. The I/O port 7 is an input/output interface, receives information from the GPRS short message transceiver 11 and the membrane keyboard 9, and the embedded single-chip microcomputer 6 coordinates the working sequence, and can output commands to the high-power actuator 10, and can also transmit to the GPRS. The short message transceiver 11 sends an instruction to send relevant information to the first and second level administrators. The USB port 12 can be connected to the USB flash drive to copy the history record of the flash memory 8 to the USB flash drive. The history of the flash memory 8 can be deleted by the level 1 administrator. Use U disk to copy the history stored in the flash memory, record more than 5000 sets of data, and copy it once every three months. After the record is more than 5000 times, the latest 5000 sets of data are always kept according to the advanced and outgoing rules, and the data is saved in the xls format.

The embedded single-chip microcomputer and the embedded special control software specify the working order of the units, and the software programs are solidified in the embedded single-chip microcomputer, and the detection values of the liquid level periods are regularly recorded at a predetermined time interval, such as 30 minutes. Recording a level value together with the date and time at this time forms a complete record of the history. When the instrument is applied with water under the effluent tank or the pavement overpass, when the liquid level exceeds the high limit, the embedded MCU commands the high-power actuator to turn on the main equipment pump motor power, and the liquid level drops. The low limit time pump stops working. If the liquid level does not drop when the liquid level is working, the high level of the standby device setting The limit is higher than the high limit of the main device, and the liquid level reaches the high limit set by the standby device. At this time, the embedded MCU sends an alarm request to the GPRS short message transceiver to send a short message, and at the same time, the standby device is turned on, and the first-level administrator receives the short message after receiving the message. Or SMS to inform the secondary administrator whether to go to the site for investigation.

Figure 3 and Figure 4 are the schematic diagrams of the liquid level upper limit alarm and the liquid level lower limit alarm setting. The membrane keyboard 9 is the input device of the present invention. For an independent sewage drain tank, the sewage automatically reaches the upper limit value before overflowing. The high-power actuator 10 is activated to open the main pump for sewage discharge. The upper limit value is AH in FIG. 3, and AL is the low water level setting value of the upper limit report. When the sewage liquid level drops to AL, the high-power actuator 10 turns off the pump. For the lower limit report of the storage liquid like the water tower type, as shown in Fig. 4, when the liquid level drops when the liquid is used, the high electric actuator 10 turns on the pump to add liquid when the liquid level alarm value AH in Fig. 4 is reached. When the bit rises to the control level A, the high voltage actuator 10 turns off the pump so that the liquid level circulates safely between the low level AH and the high level A.

In Figure 3, when the liquid level reaches the high liquid level alarm value AH, the command of the high-power actuator 10 to open the pump has been executed, but the liquid level does not fall and rises, indicating that the main pump has failed, and the standby pump is forcibly opened. The reason for being able to forcibly open is to increase the setting of the super high liquid level alarm value AHH. Generally, the value of AHH is 100 to 200 mm higher than AH. At this time, the first-level administrator SMS alarm and the first-level administrator SMS notification or telephone call. Notify the secondary administrator whether to go to the site for investigation.

In the membrane keyboard 9 in Fig. 5, in the state where the current value is displayed, press the SET button to enter the parameter setting, select the first-level administrator password, and the first-level administrator password can be modified, and input or modify the device address management number after completion. 4 is the number, set the date and time, and set the first and second level administrator mobile phone numbers according to the prompts on the interface. The two mobile phone numbers can be the same or different. The function of the device switch is to use 4 as the number 0 or 1, each bit can be selected as "1" open function, "0" off function, "0000" where the first bit indicates whether the device is allowed to receive SMS commands, the second bit indicates whether the device is allowed to send SMS alerts, the third bit is whether The relay of the No. 1 relay is allowed to issue a warning. The fourth digit is whether the relay of the No. 2 relay is allowed to issue a warning. Press the SET key again to enter the range setting. The lower limit of the range is generally set to 0. The upper limit of the range is based on the range of the high-precision liquid level sensor. For setting, the specifications of 1000, 2000, 5000, and 10000 mm are usually selected according to the height and accuracy of the liquid level controlled by the customer, and the upper limit of the range is input. Considering the requirements of the industry in the selection of liquid level units, the default unit of the invention is millimeters, and the optional units are centimeters, decimeters and meters. If the secondary administrator password is selected, the settings of low level 1AL1 high level 1AH1 and low level 2AL2 high level 2AH2 can be performed. The

liquid level

1, 2 distinguishes the main equipment and the standby liquid level value respectively, and the value of the standby equipment is more harsh than the value of the main equipment. The value is close, causing the main device to malfunction, and the standby device automatically starts to prevent an accident.

First-level administrator remote command: Under normal circumstances, one or two administrators can remotely obtain the current sensor measurement value and control the relay device's No. 2 relay operation. The edit SMS “#1000” does not contain the quoted text content and is sent to the specified The number of the device, and then the device will send the current sensor measurement value (meter display) information to the administrator. The level one administrator remote command editing message "#1001" does not contain the quoted text content, the number sent to the specified device, and then the device Will ignore the current working state of

relays

1, 2, forcing the No. 2 relay to work until the new state comes; other command information will be corrected with the firmware changes.

Figure 6 is a schematic diagram of the electrical wiring of the present invention. The

terminals

1 and 2 are normally open contacts of the intermediate relay J1 of the main device, and can control the action coil of the AC contactor, thereby connecting a large irrigation and drainage device to control the liquid level, J1 and J2 sets the specificity of the electric actuator 10. J2 is the normally open contact of the intermediate relay J2 of the standby device, and the terminal numbers are 3 and 4. Terminals 5 and 6 are connected to 220V mains, and terminal numbers 7 and 8 are terminals for connecting two-wire current type sensors. The terminals 9 to 13 are connection terminals that constitute a sensor for measuring a bridge type. The junction pins 11 and 12 are connected to the differential pressure signal of the differential pressure sensor 17, and the terminals 9 and 13 are connected to the bridge voltage of 10V.

Terminals

9, 11, 12, and 13 correspond to the four leads 21 of the dedicated gas cable 22, ensuring reliable coupling of the high-precision level sensor 1 and the operational amplifier 2.

The invention can set various functions and parameters, and the embedded single-chip computer and the control software perform digital filtering on the liquid level sensor, can detect the liquid level in real time with high precision, and receive the real-time value of the liquid level through the short message of the mobile phone network, which can be based on the liquid level. The detected value is sent to the strong electric actuator to control the liquid level within the set safe range. When the main executing device fails, the liquid level is over limit, the standby device automatically starts or the SMS is forced to start, so that the liquid level returns to safety. In the range.

The above is a further detailed description of the present invention in connection with the specific preferred embodiments, and the specific embodiments of the present invention are not limited to the description. It will be apparent to those skilled in the art that the present invention may be made without departing from the spirit and scope of the invention.

Claims

A high-precision liquid level sensor, comprising: a base (14), a base (15), an intermediate joint (16), a differential pressure sensor (17), a sheath joint (18), and a special gas cable sheath ( 19) a special gas cable (22), a stainless steel filter net cover (25); the sheath joint (18) and the special gas cable sheath (19) are connected to the intermediate joint (16), the base ( 14) is connected to the base (15), the intermediate joint (16) is connected to the base (15), and the stainless steel filter sleeve (25) is disposed on the base (15) and the base ( 14), the differential pressure sensor (17) includes a high end (26) and a low end (23), the high end (26) liquid below the liquid level, the low end (23) above the liquid level At atmospheric pressure, the differential pressure sensor (17) is disposed in a base (15), the base (14) is provided with a hole for conducting a liquid, and the special gas cable (22) is provided with an air tube (20). The lower end (23) is connected to the through-air tube (20), and the dedicated gas cable (22) is provided with a lead wire (21).
A high-precision liquid level sensor according to claim 1, wherein said differential pressure sensor is of the type 24CCFA6D.
A high-precision liquid level sensor according to claim 1, wherein the liquid-conducting hole of the base (14) is an inclined hole, and the liquid-conducting hole of the base (14) is three. Four or five.
A high-precision liquid level sensor according to claim 1, wherein said base (14) is connected to said base (15) by threads, said intermediate joint (16) and base (15) Sealed by an O-ring (24).
A high-precision liquid level sensor according to claim 1, wherein said high end (26) is provided with a liquid pressure sensing film.
A liquid level remote sensing remote control apparatus comprising the high precision liquid level sensor (1) according to any one of claims 1 to 5, further comprising an operational amplifier (2), an A/D converter (3), Embedded microcontroller (6), I/O port (7), membrane keyboard (9), strong electric actuator (10), GPRS short message transceiver (11), embedded special control software (13); the differential pressure The electrical signal of the sensor (17) is amplified by the operational amplifier (2), and then the analog signal is converted into a digital signal by the A/D converter (3) for processing by the embedded microcontroller (6). The membrane keyboard (9) is used to set parameters. When the liquid level exceeds the high limit, the embedded single-chip microcomputer (6) commands the high-power actuator (10) to turn on the power supply of the main equipment pump motor. Drop, the pump stops working when it drops to the low limit; if the liquid level does not drop when the liquid level is working, the high limit of the standby device is higher than the main The high limit of the device, the liquid level reaches the high limit set by the standby device. At this time, the embedded single chip (6) sends an alarm request to the GPRS short message transceiver (11) to send a short message, and simultaneously turns on the standby device.
The liquid level remote sensing remote control device according to claim 6, wherein the parameters set by the membrane keyboard (9) include a setting of a high-precision liquid level range, a low-limit limit, a high-limit setting, and a first-level administrator. Password settings, mobile number settings, and parameter settings for forced activation of alternate devices.
A liquid level remote sensing remote control apparatus according to claim 6, further comprising a power source (4) through which all of the units are powered.
The liquid level remote sensing remote control device according to claim 6, characterized in that the USB port (12) is included, and the USB port (12) always keeps the latest data according to the advanced and outgoing rules, and the data is saved in the xls format.
The liquid level remote sensing remote control device according to claim 6, comprising: a liquid crystal display (5), a flash memory (8), and parameters set by the thin film keyboard (9) are displayed on the liquid crystal display (5) And stored in the flash memory (8).