Intelligent automatic control system of submersible electric pump for brine well water lifting and implementation method

Abstract

The invention discloses an intelligent automatic control system of a submersible electric pump for brine well water lifting and an implementation method, and belongs to the technical field of motor control, the intelligent automatic control system comprises a frequency converter, an L terminal and an N terminal of the frequency converter are connected with an AC220V power supply, an S terminal and a T terminal of the frequency converter are connected with a submersible electric pump W1, and a current transformer CT1 is connected between the submersible electric pump W1 and the T terminal of the frequency converter in series; the current transformer CT1 is connected with an AC / DC converter, and the AC / DC converter is connected with the in-phase end of a comparison operational amplifier OP1, the anti-phase end of a comparison operational amplifier OP2 and the in-phase end of a comparison operational amplifier OP3. The device has the following advantages that the rotating speed of the blades of the submersible electric pump can be automatically adjusted according to the viscosity of brine, the brine outlet flow is kept constant when the viscosity changes, the rotating speed of the submersible electric pump is automatically adjusted to keep the liquid level balance of a brine well, and the motor of the submersible electric pump is prevented from being burnt due to idling and stalling by monitoring the current of the submersible electric pump.

Description

Technical Field

[0001] The invention discloses an intelligent automatic control system of a submersible electric pump for extracting water from a brine well and a realization method thereof, and belongs to the field of electric motor control. Background Art

[0002] Brine wells, also known as salt wells, are wells dug to extract underground salt mines. Brine well water extraction refers to the use of mining equipment such as brine submersible electric pumps to extract brine from underground to the ground to extract inorganic salts and rare elements. my country is rich in salt lake resources and has a long history of brine mining in salt wells. With the development of modern industry, the demand for mineral resources has increased, and the number of brine wells has also been increasing. Since the salt field is located in a remote area, the number of brine wells is large and the distribution is relatively scattered, with a long distance between each other. It is difficult to control the brine wells. Inadequate supervision and maintenance often lead to reduced brine production and damage to brine mining equipment.

[0003] The existing technology is to manually inspect, check the voltage meter and current meter values ​​of the submersible electric pump on site, visually observe the brine flow rate and the liquid level of the brine well, and manually adjust the brine extraction parameters, but it has the following disadvantages: 1. Inefficiency Manual on-site inspections and manual adjustment of brine extraction parameters require a lot of manpower and material resources, with a long cycle and low efficiency; 2. High energy consumption In the fixed working mode of the submersible pump, it cannot adapt to the dynamic changes of brine, and the submersible pump starts and stops frequently, resulting in energy waste; 3. The equipment is easily damaged In the case of siltation, the speed of the submersible electric pump slows down or even stalls, and the large current can easily burn it out; in the case of excessive brine flow rate, the brine submersible electric pump runs dry and idle, and loses water lubrication and cooling, making it prone to overheating and damage. Summary of the invention

[0004] The technical problem to be solved by the present invention is to address the above shortcomings and provide an intelligent automatic control system and implementation method for a submersible electric pump for extracting water from brine wells. The system can automatically adjust the speed of the submersible electric pump blades according to the viscosity of the brine, keep the brine flow rate constant when the viscosity changes, and automatically adjust the speed of the submersible electric pump to keep the liquid level balance of the brine well. By monitoring the current of the submersible electric pump, idling and blocking can be prevented to prevent the submersible electric pump motor from burning out.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: An intelligent automatic control system for a submersible electric pump for extracting water from a brine well, comprising a frequency converter, wherein the L terminal and the N terminal of the frequency converter are connected to an AC220V power supply, the S terminal and the T terminal of the frequency converter are connected to a submersible electric pump W1, a current transformer CT1 is connected in series between the submersible electric pump W1 and the T terminal of the frequency converter, the current transformer CT1 is connected to an AC / DC converter, and the AC / DC converter is connected to a non-inverting terminal of a comparison operational amplifier OP1, an inverting terminal of a comparison operational amplifier OP2, and a non-inverting terminal of a comparison operational amplifier OP3; The intelligent automatic control system also includes a laser altimeter HT1, which is installed at the brine wellhead, and the V-OUT terminal of the laser altimeter HT1 is connected to one end of a resistor R1, and the other end of the resistor R1 is connected to the FV terminal of the frequency converter; The PWM terminal of the frequency converter is connected to a conductivity detection electrode CP1, and the conductivity detection electrode CP1 is immersed below the brine liquid level near the submersible electric pump W1.

[0006] Furthermore, the FWD terminal of the inverter is connected to one end of the normally open contact KM1-1 of the forward relay, the other end of the normally open contact KM1-1 of the forward relay is connected to one end of the normally closed contact KM2-2 of the reverse relay, the other end of the normally closed contact KM2-2 of the reverse relay is connected to the COM terminal of the inverter and grounded, and the REV terminal of the inverter is connected to one end of the normally open contact KM2-1 of the reverse relay, the other end of the normally open contact KM2-1 of the reverse relay is connected to the COM terminal of the inverter and grounded.

[0007] Furthermore, the inverting end of the comparison operational amplifier OP1 is connected to one end of the resistor R2 and one end of the adjustable resistor RV3, the other end of the resistor R2 is connected to the DC24V power supply, the other end of the adjustable resistor RV3 is grounded, the output end of the comparison operational amplifier OP1 is connected to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to the negative electrode of the diode D2 and the G electrode of the field effect transistor FET1, the D electrode of the field effect transistor FET1 is connected to the DC24V power supply, the S electrode of the field effect transistor FET1 is connected to one end of the forward relay coil KM1-0, and the other end of the forward relay coil KM1-0 is grounded.

[0008] Furthermore, the output end of the comparison operational amplifier OP2 is connected to the positive electrode of the diode D2, the in-phase end of the comparison operational amplifier OP2 is connected to one end of the resistor R3 and one end of the adjustable resistor RV4, the other end of the resistor R3 is connected to the DC24V power supply, and the other end of the adjustable resistor RV4 is grounded.

[0009] Furthermore, the inverting end of the comparison operational amplifier OP3 is connected to one end of a resistor R4 and one end of an adjustable resistor RV5, the other end of the resistor R4 is connected to a DC24V power supply, the other end of the adjustable resistor RV5 is grounded, the output end of the comparison operational amplifier OP3 is connected to the G pole of the field effect transistor FET2, the D pole of the field effect transistor FET2 is connected to the DC24V power supply, the S pole of the field effect transistor FET2 is connected to one end of the reversal relay coil KM2-0, and the other end of the reversal relay coil KM2-0 is grounded.

[0010] Furthermore, the other end of the resistor R1 is also connected to one end of an adjustable resistor RV2, the other end of the adjustable resistor RV2 is grounded, the VCC terminal of the laser altimeter HT1 is connected to a DC24V power supply, and the GND terminal of the laser altimeter HT1 is grounded; One end of the conductivity detection electrode CP1 is connected to a DC24V power supply, the other end of the conductivity detection electrode CP1 is connected to one end of an adjustable resistor RV1 and a PWM terminal of a frequency converter, and the other end of the adjustable resistor RV1 is grounded.

[0011] A method for realizing an intelligent automatic control system of a submersible electric pump for extracting water from a brine well comprises the following steps: Step 1: Automatically adjust the blade speed of the submersible electric pump W1 according to the viscosity of the brine to maintain the brine flow rate: The conductivity detection electrode CP1 is immersed below the brine liquid level near the submersible electric pump W1. Because the brine is conductive, a resistor Rp with a certain resistance is formed at both ends of the conductivity detection electrode CP1. The higher the brine concentration, the smaller the resistance of the resistor Rp. On the contrary, the lower the brine concentration, the larger the resistance of the resistor Rp. The adjustable resistor RV1 and the resistor Rp are connected in series to form a voltage divider circuit. The DC24V power supply is connected to the PWM terminal of the inverter through the voltage divider of the adjustable resistor RV1 to generate a voltage Vp to the ground. The higher the brine concentration, the lower the voltage divided by the resistor Rp, and the higher the voltage Vp to the ground; on the contrary, the lower the brine concentration, the lower the voltage Vp to the ground. The calculation formula is as follows: ; When the concentration of brine increases due to geological reasons, the resistance Rp decreases, the voltage Vp generated by the inverter PWM terminal to the ground increases, and the inverter adjusts the duty cycle of the sinusoidal pulse width of the output voltage to increase the effective value of the voltage of the submersible pump W1. The blade speed of the submersible pump W1 increases to compensate for the increase in the viscosity of the brine, so that the water extraction volume remains unchanged; Assume that under a certain viscosity of brine, the voltage between the inverter PWM terminal and the ground is Vp1, and the duty cycle of the sinusoidal pulse width of the inverter to adjust the output voltage is PW1. After the viscosity of the brine changes, the voltage between the inverter PWM terminal and the ground becomes Vp2, then the duty cycle of the sinusoidal pulse width needs to be PW2, satisfying the formula , which can ensure that the amount of water pumped remains unchanged; By adjusting the resistance value of the adjustable resistor RV1, the voltage divider ratio of the adjustable resistor RV1 can be adjusted, the voltage Vp value to ground under the same brine concentration can be modified, and the blade speed of the submersible electric pump W1 can be adjusted to ensure that the water lifting volume remains unchanged.

[0012] Furthermore, the implementation method further includes step 2, automatically adjusting the blade speed of the submersible electric pump W1 according to the brine liquid level: The output voltage of the V-OUT terminal of the laser altimeter HT1 is divided by the resistor R1 and the adjustable resistor RV2. The voltage Vh of the adjustable resistor RV2 to the ground is connected to the FV terminal of the frequency converter. When the brine level changes, the voltage of the V-OUT terminal of the laser altimeter HT1 changes, the voltage Vh of the adjustable resistor RV2 to the ground changes, the output frequency of the FV terminal of the frequency converter is adjusted, and the speed of the submersible pump W1 is adjusted to keep the liquid level at a constant position. By adjusting the resistance value of the adjustable resistor RV2, the voltage division ratio of the adjustable resistor RV2 can be adjusted, which is: ; Set the middle suitable value of the brine level. At this time, the median voltage of the FV terminal of the inverter is Vh0, and the output voltage of the V-OUT terminal of the laser altimeter HT1 is V0. By adjusting the resistance value of the adjustable resistor RV2, the voltage Vh of the adjustable resistor RV2 to the ground is equal to the median voltage Vh0 of the FV terminal of the inverter. Under this voltage, the output frequency of the inverter remains unchanged, that is, ; Set the upper limit of the brine level, the output voltage of the V-OUT terminal of the laser altimeter HT1 is V1, and the voltage of the FV terminal of the inverter is , which is greater than the median voltage Vh0, the output voltage of the inverter increases, the impeller speed of the submersible pump W1 increases, and the brine level gradually decreases; Set the lower limit of the brine level, the output voltage of the V-OUT terminal of the laser altimeter HT1 is V2, and the voltage of the FV terminal of the inverter is , which is less than the median voltage Vh0, the inverter output frequency decreases, the impeller speed of the submersible pump W1 decreases, and the brine level gradually increases; After n cycles of detection and adjustment, Vh2 gradually increases and approaches Vh0. When the brine level reaches the middle, the voltage at the FV terminal of the inverter is equal to the median voltage Vh0, the output frequency of the inverter remains unchanged, and the brine level remains unchanged at the middle value.

[0013] Furthermore, the implementation method further includes step 3, the submersible electric pump W1 reverses to desilt: The current transformer monitors the operating current of the submersible pump W1. When siltation occurs, the current increases to the threshold value, the inverter's reverse function is activated, and the blades of the submersible pump W1 reverse to discharge the silt. The current transformer CT1 is installed on the wire between the frequency converter and the submersible pump W1. The current generated by the operation of the submersible pump W1 generates an alternating induced electromotive force on the current transformer CT1 due to the AC mutual inductance. The magnitude of the alternating induced voltage is proportional to the operating current of the submersible pump W1. The AC / DC converter converts the alternating induced voltage on the current transformer CT1 into a DC voltage U1, which is connected to the non-inverting terminal of the comparison operational amplifier OP3; The resistor R4 and the adjustable resistor RV5 form a voltage divider circuit, the inverting terminal of the comparison operational amplifier OP3 is connected to the upper end of the adjustable resistor RV5, and the inverting voltage of the comparison operational amplifier OP3 is U2; When the in-phase voltage U1 of the comparison operational amplifier OP3 is greater than the inverting voltage U2, the output terminal of the comparison operational amplifier OP3 is at a high level, the field effect tube FET2 is turned on, the reversing relay coil KM2-0 is energized, the reversing relay normally open contact KM2-1 is turned on, the inverter REV terminal is short-circuited with the inverter COM terminal through the reversing relay normally open contact KM2-1, the inverter outputs a reverse voltage and frequency, the submersible pump W1 reverses, and the sediment inside the blades of the submersible pump W1 is discharged; When the sediment is discharged, the current of the submersible electric pump W1 decreases, the inverting voltage U2 of the comparison operational amplifier OP3 is greater than the in-phase voltage U1, the output end of the comparison operational amplifier OP3 is at a low level, the field effect transistor FET2 connected to the output end of the comparison operational amplifier OP3 is cut off, the reversing relay coil KM2-0 is not energized, the reversing relay normally open contact KM2-1 is disconnected, and the inverter stops reverse output.

[0014] Furthermore, the implementation method further includes step 4, monitoring the current of the submersible electric pump W1 to prevent the submersible electric pump W1 from idling or being blocked and burned out when it is exposed to the water surface: Assuming that the idling current of the submersible pump W1 is A1 and the locked-rotor current is A2, then the working current of the submersible pump W1 greater than A1 and less than A2 is considered as the normal working current; Resistor R2 and adjustable resistor RV3 form a voltage divider circuit to provide an inverting reference voltage U3 to the inverting terminal of the comparison operational amplifier OP1. Resistor R3 and adjustable resistor RV4 form a voltage divider circuit to provide an inverting reference voltage U4 to the inverting terminal of the comparison operational amplifier OP2. By adjusting the resistance values ​​of adjustable resistors RV3 and RV4, U3 <U4; The current transformer CT1 is installed on the conductor between the frequency converter and the submersible pump W1. The current generated by the operation of the submersible pump W1 generates an alternating induced electromotive force on CT1 due to the AC mutual inductance. The magnitude of the alternating induced voltage is proportional to the operating current of the submersible pump W1. The AC / DC converter converts the alternating induced voltage on the current transformer CT1 into a DC voltage U1, and simultaneously connects it to the inverting terminal of the comparison operational amplifier OP2 and the non-inverting terminal of the comparison operational amplifier OP1. The comparison operational amplifier OP1 and the comparison operational amplifier OP2 form a window comparison circuit; when U3 < U1 < U4, that is, when U1 is between U3 and U4, both the comparison operational amplifier OP1 and the comparison operational amplifier OP2 output a high level, the forward relay coil KM1-0 is energized, and the normally open contact KM1-1 of the forward relay is turned on. The FWD terminal of the frequency converter is short-circuited through the normally open contact KM1-1 of the forward relay and the common terminal COM, and the submersible pump W1 operates normally; When U1 < U3 or U1 > U4, and the submersible pump W1 is in an idling state, both the comparison operational amplifier OP1 and the comparison operational amplifier OP2 output a low level, the forward relay coil KM1-0 is disconnected, and the submersible pump W1 stops operating.

[0015] Adopting the above technical solutions, compared with the prior art, the present invention has the following technical effects: The present invention can automatically adjust the blade speed of the submersible pump according to the brine viscosity, keep the brine output flow constant when the viscosity changes, and automatically adjust the speed of the submersible pump to maintain the balance of the brine well liquid level. By monitoring the current of the submersible pump, it can prevent the submersible pump motor from burning out due to idling and blocking.

[0016] 1. Realize automatic control: Realize the automation of the brine extraction process, reduce manual intervention, improve the economic benefits of brine extraction efficiency, and reduce the manual inspection cost by 60%.

[0017] 2. Reduce energy consumption: Real-time monitor the brine well liquid level height and brine viscosity through sensors, optimize the brine extraction parameters, reduce the brine extraction energy consumption, and reduce energy waste by 20% through precise control.

[0018] 3. Realize equipment protection: Control the brine well liquid level height by adjusting the brine output flow by collecting sensor data, avoid damage to the submersible pump due to dry running and idling; and monitor the equipment current. In case of siltation, start reverse cleaning; in case of overcurrent during blocking, quickly cut off the power supply of the submersible pump to avoid motor burnout, extend the equipment life by 30%, and reduce the equipment failure rate by 70%. Brief Description of the Drawings

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0020] Figure 1 It is the circuit diagram of the intelligent automatic control system for lifting water from the brine well in the present invention. DETAILED DESCRIPTION

[0021] Examples, such as Figure 1 As shown, an intelligent automatic control system for a submersible electric pump for extracting water from a brine well includes a frequency converter, wherein the L terminal and the N terminal of the frequency converter are connected to an AC220V power supply, the S terminal and the T terminal of the frequency converter are connected to a submersible electric pump W1, a current transformer CT1 is connected in series between the submersible electric pump W1 and the T terminal of the frequency converter, the current transformer CT1 is connected to an AC / DC converter, the FWD terminal of the frequency converter is connected to one end of a normally open contact KM1-1 of a forward relay, the other end of the normally open contact KM1-1 of the forward relay is connected to one end of a normally closed contact KM2-2 of a reverse relay, the other end of the normally closed contact KM2-2 of the reverse relay is connected to the COM terminal of the frequency converter and is grounded, the REV terminal of the frequency converter is connected to one end of a normally open contact KM2-1 of a reverse relay, the other end of the normally open contact KM2-1 of the reverse relay is connected to the COM terminal of the frequency converter and is grounded.

[0022] The intelligent automatic control system also includes a comparison operational amplifier OP1, the in-phase end of the comparison operational amplifier OP1 is connected to the AC / DC converter, the inverting end of the comparison operational amplifier OP1 is connected to one end of a resistor R2 and one end of an adjustable resistor RV3, the other end of the resistor R2 is connected to a DC24V power supply, the other end of the adjustable resistor RV3 is grounded, the output end of the comparison operational amplifier OP1 is connected to the positive electrode of a diode D1, the negative electrode of the diode D1 is connected to the negative electrode of the diode D2 and the G electrode of the field effect tube FET1, the D electrode of the field effect tube FET1 is connected to the DC24V power supply, the S electrode of the field effect tube FET1 is connected to one end of a forward relay coil KM1-0, and the other end of the forward relay coil KM1-0 is grounded.

[0023] The intelligent automatic control system also includes a comparison operational amplifier OP2, the inverting end of the comparison operational amplifier OP2 is connected to the AC / DC converter, the output end of the comparison operational amplifier OP2 is connected to the positive electrode of the diode D2, the in-phase end of the comparison operational amplifier OP2 is connected to one end of the resistor R3 and one end of the adjustable resistor RV4, the other end of the resistor R3 is connected to a DC24V power supply, and the other end of the adjustable resistor RV4 is grounded.

[0024] The intelligent automatic control system also includes a comparison operational amplifier OP3, the same-phase end of the comparison operational amplifier OP3 is connected to the AC / DC converter, the inverting end of the comparison operational amplifier OP3 is connected to one end of a resistor R4 and one end of an adjustable resistor RV5, the other end of the resistor R4 is connected to a DC24V power supply, the other end of the adjustable resistor RV5 is grounded, the output end of the comparison operational amplifier OP3 is connected to the G pole of the field effect tube FET2, the D pole of the field effect tube FET2 is connected to the DC24V power supply, the S pole of the field effect tube FET2 is connected to one end of a reversing relay coil KM2-0, and the other end of the reversing relay coil KM2-0 is grounded.

[0025] The intelligent automatic control system also includes a laser altimeter HT1, which is installed at the brine wellhead. The V-OUT terminal of the laser altimeter HT1 is connected to one end of a resistor R1, the other end of the resistor R1 is connected to the FV terminal of the frequency converter and one end of an adjustable resistor RV2, the other end of the adjustable resistor RV2 is grounded, the VCC terminal of the laser altimeter HT1 is connected to a DC24V power supply, and the GND terminal of the laser altimeter HT1 is grounded.

[0026] The intelligent automatic control system also includes a conductivity detection electrode CP1, one end of the conductivity detection electrode CP1 is connected to a DC24V power supply, the other end of the conductivity detection electrode CP1 is connected to one end of an adjustable resistor RV1 and a PWM terminal of a frequency converter, the other end of the adjustable resistor RV1 is grounded, and the conductivity detection electrode CP1 is immersed below the brine liquid level near the submersible electric pump W1.

[0027] The PWM terminal of the frequency converter is a sinusoidal pulse width modulation input terminal. By adjusting the voltage value of the PWM terminal of the frequency converter to the ground, the sinusoidal pulse width of the frequency converter output voltage can be modulated to change the speed of the submersible electric pump W1; the FV terminal of the frequency converter is a frequency modulation input terminal. By adjusting the voltage value of the FV terminal to the ground, the frequency of the frequency converter output voltage can be modulated to change the speed of the submersible electric pump W1; the FWD terminal of the frequency converter is a forward signal input terminal. When the FWD terminal and the common terminal COM are short-circuited, the frequency converter outputs a positive frequency voltage, and the submersible electric pump W1 rotates forward to perform water pumping operations; the REV terminal of the frequency converter is a reverse signal input terminal. When the REV terminal and the common terminal COM are short-circuited, the frequency converter outputs a reverse frequency voltage, and the submersible electric pump W1 reverses to perform dredging operations.

[0028] A method for realizing an intelligent automatic control system of a submersible electric pump for extracting water from a brine well comprises the following steps: Step 1: Automatically adjust the blade speed of the submersible electric pump W1 according to the viscosity of the brine to maintain the brine flow rate: The conductivity detection electrode CP1 is immersed below the brine liquid level near the submersible electric pump W1. Because the brine is conductive, a resistor Rp with a certain resistance is formed at both ends of the conductivity detection electrode CP1. The higher the brine concentration, the smaller the resistance of the resistor Rp. Conversely, the lower the brine concentration, the larger the resistance of the resistor Rp.

[0029] The adjustable resistor RV1 and the resistor Rp are connected in series to form a voltage divider circuit. The DC24V power supply is connected to the PWM terminal of the inverter through the voltage divider of the adjustable resistor RV1 to generate a voltage Vp to the ground. The higher the brine concentration, the lower the voltage divided by the resistor Rp, and the higher the voltage Vp to the ground; on the contrary, the lower the brine concentration, the lower the voltage Vp to the ground. The calculation formula is as follows: .

[0030] Because the increase of solute will enhance the cohesion of brine, the higher the concentration, the greater the viscosity of brine, the greater the resistance to the blades of submersible electric pump W1. If the submersible electric pump W1 does not increase the voltage and increase the blade speed, the water pumping capacity will become smaller.

[0031] When the brine concentration increases due to geological reasons, the resistance Rp decreases, the voltage Vp generated by the inverter PWM terminal to the ground increases, the inverter adjusts the duty cycle of the sinusoidal pulse width of the output voltage, increases the effective value of the voltage of the submersible pump W1, and the blade speed of the submersible pump W1 increases to compensate for the increase in brine viscosity and keep the water extraction volume unchanged.

[0032] Assume that under a certain viscosity of brine, the voltage between the inverter PWM terminal and the ground is Vp1, and the duty cycle of the sinusoidal pulse width of the inverter to adjust the output voltage is PW1. After the viscosity of the brine changes, the voltage between the inverter PWM terminal and the ground becomes Vp2, then the duty cycle of the sinusoidal pulse width needs to be PW2, satisfying the formula , which can ensure that the amount of water pumped remains unchanged.

[0033] By adjusting the resistance value of the adjustable resistor RV1, the voltage divider ratio of the adjustable resistor RV1 can be adjusted, the voltage Vp value to ground under the same brine concentration can be modified, and the blade speed of the submersible electric pump W1 can be adjusted to ensure that the water lifting volume remains unchanged.

[0034] Step 2, automatically adjust the blade speed of the submersible electric pump W1 according to the brine liquid level, so as to keep the brine well liquid level at the middle value, realize the smooth operation of the submersible electric pump W1, and save power consumption: The laser altimeter HT1 is installed at the brine wellhead to monitor the brine liquid level. The lower the brine liquid level is, the greater the distance between the liquid level and the laser altimeter HT1 is, and the smaller the output voltage of the V-OUT terminal of the laser altimeter HT1 is. On the contrary, the higher the brine liquid level is, the smaller the distance between the liquid level and the laser altimeter HT1 is, and the larger the output voltage of the V-OUT terminal of the laser altimeter HT1 is.

[0035] The output voltage of the V-OUT terminal of the laser altimeter HT1 is divided by the resistor R1 and the adjustable resistor RV2. The voltage Vh of the adjustable resistor RV2 to ground is connected to the FV terminal of the inverter. When the brine level changes, the voltage of the V-OUT terminal of the laser altimeter HT1 changes, the voltage Vh of the adjustable resistor RV2 to ground changes, the output frequency of the FV terminal of the inverter is adjusted, and the speed of the submersible pump W1 is adjusted to keep the liquid level at a constant position.

[0036] Furthermore, by adjusting the resistance value of the adjustable resistor RV2, the voltage division ratio of the adjustable resistor RV2 can be adjusted, as follows: ; Set the middle suitable value of the brine level. At this time, the median voltage of the FV terminal of the inverter is Vh0, and the output voltage of the V-OUT terminal of the laser altimeter HT1 is V0. By adjusting the resistance value of the adjustable resistor RV2, the voltage Vh of the adjustable resistor RV2 to the ground is equal to the median voltage Vh0 of the FV terminal of the inverter. Under this voltage, the output frequency of the inverter remains unchanged, that is, ; Set the upper limit of the brine level, the output voltage of the V-OUT terminal of the laser altimeter HT1 is V1, and the voltage of the FV terminal of the inverter is , which is greater than the median voltage Vh0, the output voltage of the inverter increases, the impeller speed of the submersible electric pump W1 increases, and the brine level gradually decreases.

[0037] Set the lower limit of the brine level, the output voltage of the V-OUT terminal of the laser altimeter HT1 is V2, and the voltage of the FV terminal of the inverter is , which is less than the median voltage Vh0, the inverter output frequency decreases, and the impeller speed of the submersible electric pump W1 decreases, causing the brine level to gradually increase.

[0038] After n cycles of detection and adjustment, Vh2 gradually increases and approaches Vh0. When the brine level reaches the middle, the voltage at the FV terminal of the inverter is equal to the median voltage Vh0, the output frequency of the inverter remains unchanged, and the brine level remains unchanged at the middle value.

[0039] Step 3: Submersible electric pump W1 reverses to clear the silt: Because the blades of the submersible electric pump W1 are blocked by sludge, debris, etc., the rotational resistance of the submersible electric pump W1 becomes larger, the water extraction amount becomes smaller, and the brine level rises. At this time, increasing the rotation speed of the submersible electric pump W1 to increase the water extraction amount will cause serious blockage and cause the blades of the submersible electric pump W1 to get stuck. The present invention monitors the operating current of the submersible electric pump W1 through a current transformer. When siltation occurs, the current increases to a threshold value, the reverse function of the inverter is started, and the blades of the submersible electric pump W1 are reversed to discharge the silt.

[0040] The current transformer CT1 is installed on the conductor between the frequency converter and the submersible pump W1. The current generated by the operation of the submersible pump W1 generates an alternating induced electromotive force on the current transformer CT1 due to the AC mutual inductance. The magnitude of the alternating induced voltage is proportional to the operating current of the submersible pump W1.

[0041] The AC / DC converter converts the alternating induced voltage on the current transformer CT1 into a DC voltage U1, which is connected to the non-inverting terminal of the comparison operational amplifier OP3.

[0042] The resistor R4 and the adjustable resistor RV5 form a voltage divider circuit, the inverting terminal of the comparison operational amplifier OP3 is connected to the upper end of the adjustable resistor RV5, and the inverting voltage of the comparison operational amplifier OP3 is U2.

[0043] When the in-phase voltage U1 of the comparison operational amplifier OP3 is greater than the inverting voltage U2, the output terminal of the comparison operational amplifier OP3 is at a high level, the field effect tube FET2 is turned on, the reversing relay coil KM2-0 is energized, the reversing relay normally open contact KM2-1 is turned on, the REV terminal of the inverter is short-circuited with the COM terminal of the inverter through the reversing relay normally open contact KM2-1, the inverter outputs a reverse voltage and frequency, the submersible pump W1 reverses, and the sediment inside the blades of the submersible pump W1 is discharged.

[0044] When the sediment is discharged, the current of the submersible electric pump W1 decreases, the inverting voltage U2 of the comparison operational amplifier OP3 is greater than the in-phase voltage U1, the output end of the comparison operational amplifier OP3 is at a low level, the field effect transistor FET2 connected to the output end of the comparison operational amplifier OP3 is cut off, the reversing relay coil KM2-0 is not energized, the reversing relay normally open contact KM2-1 is disconnected, and the inverter stops reverse output.

[0045] Step 4, monitor the current of the submersible pump W1 to prevent the submersible pump W1 from idling and burning out of the water surface, and prevent the submersible pump W1 from being blocked and burning: The geological conditions of the brine well are complex, and there may be formation leakage, and the brine level may drop sharply suddenly. At this time, the submersible pump W1 is exposed to the water surface and idles. Because it loses the lubrication and cooling of water, the submersible pump W1 will burn out after idling for a period of time; because the sludge and debris block the blades of the submersible pump W1, after the submersible pump W1 is desilted, the debris is not discharged, the submersible pump W1 is blocked, and the current is very large. If the power supply is not stopped in time, the submersible pump W1 will overheat and burn.

[0046] Assuming that the idling current of the submersible electric pump W1 is A1 and the locked-rotor current is A2, the working current of the submersible electric pump W1 greater than A1 and less than A2 is regarded as the normal working current.

[0047] Resistor R2 and adjustable resistor RV3 form a voltage divider circuit to provide an inverting reference voltage U3 to the inverting terminal of the comparison operational amplifier OP1. Resistor R3 and adjustable resistor RV4 form a voltage divider circuit to provide an inverting reference voltage U4 to the inverting terminal of the comparison operational amplifier OP2. By adjusting the resistance values ​​of adjustable resistors RV3 and RV4, U3 <U4。

[0048] The current transformer CT1 is installed on the conductor between the frequency converter and the submersible pump W1. The current generated by the operation of the submersible pump W1 generates an alternating induced electromotive force on CT1 due to the AC mutual inductance. The magnitude of the alternating induced voltage is proportional to the operating current of the submersible pump W1.

[0049] The AC / DC converter converts the alternating induced voltage on the current transformer CT1 into a DC voltage U1, and simultaneously connects it to the inverting terminal of the comparison operational amplifier OP2 and the non-inverting terminal of the comparison operational amplifier OP1. The comparison operational amplifier OP1 and the comparison operational amplifier OP2 form a window comparison circuit; when U3 < U1 < U4, that is, when U1 is between U3 and U4, the comparison operational amplifier OP1 and the comparison operational amplifier OP2 both output high levels, the forward relay coil KM1-0 is energized, and the normally open contact KM1-1 of the forward relay is turned on. The FWD terminal of the frequency converter is short-circuited through the normally open contact KM1-1 of the forward relay and the common terminal COM, and the submersible pump W1 operates normally.

[0050] When U1 < U3 or U1 > U4, and the submersible pump W1 is in an idling state, the comparison operational amplifier OP1 and the comparison operational amplifier OP2 both output low levels, the forward relay coil KM1-0 is disconnected, and the submersible pump W1 stops operating.

[0051] For the three threshold voltage signals, the reverse voltage threshold U2, the idling voltage threshold U3, and the blocked-rotor voltage threshold U4, there is U3 < U2 < U4. Each threshold is adjusted and set through the adjustable resistors RV5, RV3, and RV4 connected thereto.

[0052] The electronic control system judges the working state of the submersible pump W1 according to the magnitude of the voltage U1 at the output end of the AC / DC converter. When U1 < U3, the judgment result is that the submersible pump W1 is idling. When U1 is greater than U3 and less than U2, the submersible pump W1 is normal. When U1 is greater than U2 and less than U4, the submersible pump W1 is silted and reversed. When U1 is greater than U4, the submersible pump W1 is blocked.

[0053] After the submersible pump W1 is reversed to clean the silt, its working current turns to a normal value, and the submersible pump W1 automatically turns to the forward state and continues to operate.

[0054] When the submersible pump W1 stops due to idling and blocked rotation, since the current drops to zero, the system will not start by itself. It is forced to start through the RMT terminal of the frequency converter for remote communication control. If the idling and blocked-rotation states disappear, the frequency converter can resume normal operation.

[0055] If the idling and blocked-rotation states continue to exist, an alarm message is sent through the RMT port of the frequency converter for remote communication control to remind for on-site inspection by personnel.

[0056] The description of the present invention is given for purposes of illustration and description, and is not intended to be exhaustive or to limit the invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to best explain the principles of the invention and its practical application, and to enable those of ordinary skill in the art to understand the invention so as to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. An intelligent automatic control system for a submersible electric pump for extracting water from a brine well, characterized in that: It includes a frequency converter, wherein the L terminal and the N terminal of the frequency converter are connected to an AC220V power supply, the S terminal and the T terminal of the frequency converter are connected to a submersible electric pump W1, a current transformer CT1 is connected in series between the submersible electric pump W1 and the T terminal of the frequency converter, the current transformer CT1 is connected to an AC / DC converter, and the AC / DC converter is connected to a non-inverting terminal of a comparison operational amplifier OP1, an inverting terminal of a comparison operational amplifier OP2, and a non-inverting terminal of a comparison operational amplifier OP3; The intelligent automatic control system also includes a laser altimeter HT1, which is installed at the brine wellhead, and the V-OUT terminal of the laser altimeter HT1 is connected to one end of a resistor R1, and the other end of the resistor R1 is connected to the FV terminal of the frequency converter; The PWM terminal of the frequency converter is connected to a conductivity detection electrode CP1, and the conductivity detection electrode CP1 is immersed below the brine liquid level near the submersible electric pump W1.

2. The intelligent automatic control system for a submersible electric pump for extracting water from a brine well as claimed in claim 1, characterized in that: The FWD terminal of the inverter is connected to one end of the normally open contact KM1-1 of the forward relay, the other end of the normally open contact KM1-1 of the forward relay is connected to one end of the normally closed contact KM2-2 of the reverse relay, the other end of the normally closed contact KM2-2 of the reverse relay is connected to the COM terminal of the inverter and grounded, and the REV terminal of the inverter is connected to one end of the normally open contact KM2-1 of the reverse relay, the other end of the normally open contact KM2-1 of the reverse relay is connected to the COM terminal of the inverter and grounded.

3. The intelligent automatic control system for a submersible electric pump for extracting water from a brine well as claimed in claim 1, characterized in that: The inverting end of the comparison operational amplifier OP1 is connected to one end of the resistor R2 and one end of the adjustable resistor RV3, the other end of the resistor R2 is connected to the DC24V power supply, and the other end of the adjustable resistor RV3 is grounded. The output end of the comparison operational amplifier OP1 is connected to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to the negative electrode of the diode D2 and the G electrode of the field effect transistor FET1, the D electrode of the field effect transistor FET1 is connected to the DC24V power supply, the S electrode of the field effect transistor FET1 is connected to one end of the forward relay coil KM1-0, and the other end of the forward relay coil KM1-0 is grounded.

4. The intelligent automatic control system for a submersible electric pump for extracting water from a brine well as claimed in claim 1, characterized in that: The output end of the comparison operational amplifier OP2 is connected to the anode of the diode D2, the in-phase end of the comparison operational amplifier OP2 is connected to one end of the resistor R3 and one end of the adjustable resistor RV4, the other end of the resistor R3 is connected to the DC24V power supply, and the other end of the adjustable resistor RV4 is grounded.

5. The intelligent automatic control system for a submersible electric pump for extracting water from a brine well as claimed in claim 1, characterized in that: The inverting end of the comparison operational amplifier OP3 is connected to one end of the resistor R4 and one end of the adjustable resistor RV5, the other end of the resistor R4 is connected to the DC24V power supply, and the other end of the adjustable resistor RV5 is grounded. The output end of the comparison operational amplifier OP3 is connected to the G pole of the field effect transistor FET2, the D pole of the field effect transistor FET2 is connected to the DC24V power supply, the S pole of the field effect transistor FET2 is connected to one end of the reversing relay coil KM2-0, and the other end of the reversing relay coil KM2-0 is grounded.

6. The intelligent automatic control system for a submersible electric pump for extracting water from a brine well as claimed in claim 1, characterized in that: The other end of the resistor R1 is also connected to one end of an adjustable resistor RV2, the other end of the adjustable resistor RV2 is grounded, the VCC terminal of the laser altimeter HT1 is connected to a DC24V power supply, and the GND terminal of the laser altimeter HT1 is grounded; One end of the conductivity detection electrode CP1 is connected to a DC24V power supply, the other end of the conductivity detection electrode CP1 is connected to one end of an adjustable resistor RV1 and a PWM terminal of a frequency converter, and the other end of the adjustable resistor RV1 is grounded.

7. A method for realizing an intelligent automatic control system of a submersible electric pump for extracting water from a brine well, characterized in that: The implementation method is applied to the intelligent automatic control system of the submersible electric pump for extracting water from brine wells as claimed in any one of claims 1 to 6, and comprises the following steps: Step 1: Automatically adjust the blade speed of the submersible electric pump W1 according to the viscosity of the brine to maintain the brine flow rate: The conductivity detection electrode CP1 is immersed below the brine liquid level near the submersible electric pump W1. Because the brine is conductive, a resistor Rp with a certain resistance is formed at both ends of the conductivity detection electrode CP1. The higher the brine concentration, the smaller the resistance of the resistor Rp. On the contrary, the lower the brine concentration, the larger the resistance of the resistor Rp. The adjustable resistor RV1 and the resistor Rp are connected in series to form a voltage divider circuit. The DC24V power supply is connected to the PWM terminal of the inverter through the voltage divider of the adjustable resistor RV1 to generate a voltage Vp to the ground. The higher the brine concentration, the lower the voltage divided by the resistor Rp, and the higher the voltage Vp to the ground; on the contrary, the lower the brine concentration, the lower the voltage Vp to the ground. The calculation formula is as follows: ； When the concentration of brine increases due to geological reasons, the resistance Rp decreases, the voltage Vp generated by the inverter PWM terminal to the ground increases, and the inverter adjusts the duty cycle of the sinusoidal pulse width of the output voltage to increase the effective value of the voltage of the submersible pump W1. The blade speed of the submersible pump W1 increases to compensate for the increase in the viscosity of the brine, so that the water extraction volume remains unchanged; Assume that under a certain viscosity of brine, the voltage between the inverter PWM terminal and the ground is Vp1, and the duty cycle of the sinusoidal pulse width of the inverter to adjust the output voltage is PW1. After the viscosity of the brine changes, the voltage between the inverter PWM terminal and the ground becomes Vp2, then the duty cycle of the sinusoidal pulse width needs to be PW2, satisfying the formula , which can ensure that the amount of water pumped remains unchanged; By adjusting the resistance value of the adjustable resistor RV1, the voltage divider ratio of the adjustable resistor RV1 can be adjusted, the voltage Vp value to ground under the same brine concentration can be modified, and the blade speed of the submersible electric pump W1 can be adjusted to ensure that the water lifting volume remains unchanged.

8. The method for realizing the intelligent automatic control system of a submersible electric pump for extracting water from a brine well as claimed in claim 7, characterized in that: The implementation method further includes step 2, automatically adjusting the blade speed of the submersible electric pump W1 according to the brine liquid level: The output voltage of the V-OUT terminal of the laser altimeter HT1 is divided by the resistor R1 and the adjustable resistor RV2. The voltage Vh of the adjustable resistor RV2 to the ground is connected to the FV terminal of the frequency converter. When the brine level changes, the voltage of the V-OUT terminal of the laser altimeter HT1 changes, the voltage Vh of the adjustable resistor RV2 to the ground changes, the output frequency of the FV terminal of the frequency converter is adjusted, and the speed of the submersible pump W1 is adjusted to keep the liquid level at a constant position. By adjusting the resistance value of the adjustable resistor RV2, the voltage division ratio of the adjustable resistor RV2 can be adjusted, which is: ; Set the middle suitable value of the brine level. At this time, the median voltage of the FV terminal of the inverter is Vh0, and the output voltage of the V-OUT terminal of the laser altimeter HT1 is V0. By adjusting the resistance value of the adjustable resistor RV2, the voltage Vh of the adjustable resistor RV2 to the ground is equal to the median voltage Vh0 of the FV terminal of the inverter. Under this voltage, the output frequency of the inverter remains unchanged, that is, ; Set the upper limit of the brine level, the output voltage of the V-OUT terminal of the laser altimeter HT1 is V1, and the voltage of the FV terminal of the inverter is , which is greater than the median voltage Vh0, the output voltage of the inverter increases, the impeller speed of the submersible pump W1 increases, and the brine level gradually decreases; Set the lower limit of the brine level, the output voltage of the V-OUT terminal of the laser altimeter HT1 is V2, and the voltage of the FV terminal of the inverter is , which is less than the median voltage Vh0, the inverter output frequency decreases, the impeller speed of the submersible pump W1 decreases, and the brine level gradually increases; After n cycles of detection and adjustment, Vh2 gradually increases and approaches Vh0. When the brine level reaches the middle, the voltage at the FV terminal of the inverter is equal to the median voltage Vh0, the output frequency of the inverter remains unchanged, and the brine level remains unchanged at the middle value.

9. The method for realizing the intelligent automatic control system of a submersible electric pump for extracting water from a brine well as claimed in claim 7, characterized in that: The implementation method further includes step 3, the submersible electric pump W1 reverses to desilt: The current transformer monitors the operating current of the submersible pump W1. When siltation occurs, the current increases to the threshold value, the inverter's reverse function is activated, and the blades of the submersible pump W1 reverse to discharge the silt. The current transformer CT1 is installed on the wire between the frequency converter and the submersible pump W1. The current generated by the operation of the submersible pump W1 generates an alternating induced electromotive force on the current transformer CT1 due to the AC mutual inductance. The magnitude of the alternating induced voltage is proportional to the operating current of the submersible pump W1. The AC / DC converter converts the alternating induced voltage on the current transformer CT1 into a DC voltage U1 and connects it to the non-inverting input terminal of the comparator operational amplifier OP3; The resistor R4 and the adjustable resistor RV5 form a voltage dividing circuit. The inverting input terminal of the comparator operational amplifier OP3 is connected to the upper end of the adjustable resistor RV5, and the inverting voltage of the comparator operational amplifier OP3 is U2; When the non-inverting voltage U1 of the comparator operational amplifier OP3 is greater than the inverting voltage U2, the output terminal of the comparator operational amplifier OP3 is at a high level, the field effect transistor FET2 is turned on, the reverse relay coil KM2-0 is energized, and the normally open contact KM2-1 of the reverse relay is turned on. The REV terminal of the frequency converter is short-circuited to the COM terminal of the frequency converter through the normally open contact KM2-1 of the reverse relay. The frequency converter outputs a reverse voltage and frequency, and the submersible pump W1 rotates in reverse to discharge the sediment inside the impeller of the submersible pump W1; When the sediment is discharged, the current of the submersible pump W1 decreases. The inverting voltage U2 of the comparator operational amplifier OP3 is greater than the non-inverting voltage U1. The output terminal of the comparator operational amplifier OP3 is at a low level. The field effect transistor FET2 connected to the output terminal of the comparator operational amplifier OP3 is turned off, the reverse relay coil KM2-0 is not energized, and the normally open contact KM2-1 of the reverse relay is disconnected. The frequency converter stops reverse output.

10. The method for realizing the intelligent automatic control system of a submersible electric pump for extracting water from a brine well as claimed in claim 7, characterized in that: The implementation method further includes step 4 of monitoring the current of the submersible pump W1 to prevent the submersible pump W1 from idling or being blocked and burned out when exposed above the water surface: Assume that the no-load current of the submersible pump W1 is A1 and the blocked-rotor current is A2. Then, the operating current of the submersible pump W1 that is greater than A1 and less than A2 is regarded as the normal operating current; The resistor R2 and the adjustable resistor RV3 form a voltage dividing circuit to provide an inverting reference voltage U3 for the inverting input terminal of the comparator operational amplifier OP1. The resistor R3 and the adjustable resistor RV4 form a voltage dividing circuit to provide a non-inverting reference voltage U4 for the non-inverting input terminal of the comparator operational amplifier OP2. By adjusting the resistance values of the adjustable resistor RV3 and the adjustable resistor RV4, U3 < U4; The current transformer CT1 is installed on the wire between the frequency converter and the submersible pump W1. The current generated by the operation of the submersible pump W1 generates an alternating induced electromotive force on CT1 due to AC mutual induction. The magnitude of the alternating induced voltage is proportional to the operating current of the submersible pump W1; The AC / DC converter converts the alternating induced voltage on the current transformer CT1 into a DC voltage U1 and connects it to the inverting input terminal of the comparator operational amplifier OP2 and the non-inverting input terminal of the comparator operational amplifier OP1 at the same time. The comparator operational amplifier OP1 and the comparator operational amplifier OP2 form a window comparison circuit; when U3 < U1 < U4, that is, when U1 is between U3 and U4, the comparator operational amplifier OP1 and the comparator operational amplifier OP2 both output a high level, the forward relay coil KM1-0 is energized, and the normally open contact KM1-1 of the forward relay is turned on. The FWD terminal of the frequency converter is short-circuited to the common terminal COM through the normally open contact KM1-1 of the forward relay, and the submersible pump W1 operates normally; When U1 < U3 or U1 > U4 and the submersible pump W1 is in the idling state, both the comparison operational amplifier OP1 and the comparison operational amplifier OP2 output low levels simultaneously, the forward rotation relay coil KM1-0 is disconnected, and the submersible pump W1 stops running.

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