Submerged arc furnace DCS system monitoring device

Abstract

The utility model provides a monitoring device for a DCS (Distributed Control System) of a submerged arc furnace. The monitoring device comprises a power supply processing circuit, a control circuit, a motor driving circuit, a temperature detection circuit and a control type alarm circuit, external high-voltage alternating current supplies power to a motor in the submerged arc furnace through the motor driving circuit, and the control end of the motor driving circuit is connected to the output end of the control circuit. External high-voltage alternating current is connected to the input end of the power supply processing circuit, and the power supply processing circuit is used for converting the external high-voltage alternating current into direct-current voltage. And a temperature sensor RT1 is arranged in the temperature detection circuit. The monitoring device for the DCS system of the submerged arc furnace solves the problem that the motor cannot be controlled to operate according to the detected environment temperature of the motor in the prior art.

Description

Technical Field

[0001] This utility model relates to a monitoring device, specifically a monitoring device for a DCS system of an electric arc furnace. Background Technology

[0002] The electric arc furnace includes a motor and a mixer. The output of the motor is connected to the mixer, and the motor is used to drive the mixer to rotate in order to mix the materials.

[0003] A DCS system was designed for the management of the submerged arc furnace. In the submerged arc furnace, the DCS system is mainly used for the following aspects: 1) Data acquisition and processing: The system can acquire various operating data of the submerged arc furnace in real time, including key parameters such as temperature, pressure, and current, and provide operators with real-time production information through data processing and analysis. 2) Automatic control: Based on the acquired data, the DCS system can automatically adjust the working state of the submerged arc furnace to ensure it operates under optimal conditions, thereby improving production efficiency and product quality. 3) Fault diagnosis and alarm: The system can monitor the operating status of the equipment in real time, and immediately issue an alarm signal once an abnormality is detected, helping operators to promptly identify and resolve problems. 4) Remote monitoring and management: Through the human-machine interface, operators can remotely monitor the operation of the submerged arc furnace and perform necessary operations and management.

[0004] In a DCS system, monitoring the motor is the most crucial function, hence the design of such a monitoring device. Existing technology typically includes a main control chip and a motor driver. The main control chip's output is connected to the motor driver's control terminal, and external power is supplied directly to the motor through the motor driver. While this provides power, it has drawbacks: it cannot control motor operation based on monitored temperature, leading to motor operation at excessively high temperatures, which can cause damage and shorten the motor's lifespan. Utility Model Content

[0005] This utility model provides a monitoring device for a DCS system of a submerged arc furnace, which solves the problem in the prior art that the operation of the motor cannot be controlled based on the ambient temperature of the detected motor.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The present invention provides a DCS system monitoring device for a submerged arc furnace, comprising: a power processing circuit, a control circuit, a motor drive circuit, a temperature detection circuit, and a control alarm circuit; external high-voltage AC power supplies power to the motor in the submerged arc furnace through the motor drive circuit, and the control terminal of the motor drive circuit is connected to the output terminal of the control circuit; external high-voltage AC power is connected to the input terminal of the power processing circuit, which converts the external high-voltage AC power into DC voltage; a temperature sensor RT1 is provided in the temperature detection circuit, and the temperature sensor RT1 is located on the outer casing of the motor in the submerged arc furnace; the output terminal OUT1 of the temperature detection circuit is converted by an AD converter.

[0007] The circuit is connected to the input terminal of the control circuit; the controllable alarm circuit includes: an audible alarm unit, a first controllable switch circuit, a first judgment execution circuit, a photoelectric alarm unit, a second controllable switch circuit, and a second judgment execution circuit. The output terminal of the power processing circuit supplies power to the audible alarm unit through the first controllable switch circuit, and the output terminal of the power processing circuit supplies power to the photoelectric alarm unit through the second controllable switch circuit. The input terminals of the first and second judgment execution circuits are both connected to the output terminal OUT1 of the temperature detection circuit. The output terminal of the first judgment execution circuit is connected to the control terminal of the first controllable switch circuit, and the output terminal of the second judgment execution circuit is connected to the control terminal of the second controllable switch circuit.

[0008] Preferably, both the first and second judgment execution circuits include: a current limiting module, a comparison module, and a reference voltage module. The input terminal of the current limiting module is the input terminal of either the first or second judgment execution circuit. The output terminal of the current limiting module is connected to the voltage input terminal of the comparison module. The output terminal of the power processing circuit supplies power to the reference voltage module. The output terminal of the reference voltage module is connected to the reference input terminal of the comparison module. The output terminal of the comparison module is the output terminal of either the first or second judgment execution module.

[0009] Preferably, the current limiting module includes a diode D1, with the anode of diode D1 serving as the input terminal of the current limiting module and the cathode of diode D1 serving as the output terminal of the current limiting module.

[0010] Preferably, the comparison module includes: a comparator U2, wherein the non-inverting input terminal of the comparator U2 is the voltage input terminal of the comparison module, and the inverting input terminal of the comparator is the reference input terminal of the comparison module.

[0011] Preferably, the reference voltage module includes: a resistor R8 and a sliding resistor RV1. The first end of the resistor R8 is connected to the output terminal of the power processing circuit, the second end of the resistor R8 is connected to the first stationary end of the sliding resistor RV1, the second stationary end of the sliding resistor RV1 is grounded, the movable end of the sliding resistor RV1 is connected to the second stationary end of the sliding resistor RV1, and the first stationary end of the sliding resistor RV1 is the output terminal of the reference voltage module.

[0012] Preferably, the temperature detection circuit includes: a detection execution module and a two-stage amplification module. The circuit containing the temperature sensor RT1 is the detection execution module. The output terminal of the detection execution module is connected to the output terminal of the two-stage amplification module. The output terminal of the two-stage amplification module is the output terminal OUT1 of the temperature detection circuit. The power supply circuit supplies power to the detection execution module and the two-stage amplification module.

[0013] Preferably, the detection execution module includes: a resistor R1, the first end of which is connected to the first end of a temperature sensor RT1, the second end of the temperature sensor RT1 is connected to the output of a power processing circuit, the second end of the resistor R1 is grounded, and the first end of the resistor R1 is the output of the detection execution module.

[0014] Preferably, the power supply processing circuit includes: a transformer module, a rectifier module, and a step-down regulator module. The input terminal of the transformer module is connected to an external high-voltage AC power supply, the output terminal of the transformer module is connected to the input terminal of the rectifier module, and the output terminal of the rectifier module is connected to the output terminal of the step-down regulator module.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1) In this application, firstly, by setting a temperature sensing part in the temperature detection circuit, the temperature is detected. The control circuit controls the on and off of the motor drive circuit according to the temperature detection, thereby controlling the operation of the motor in the electric arc furnace, avoiding operation at excessively high temperatures, improving the protection of the motor in the electric arc furnace, and extending its service life.

[0017] 2) In the control alarm circuit, both the first judgment execution circuit and the second judgment execution circuit are connected to the output terminal OUT1 of the temperature detection circuit. The analog voltage detected by the temperature detection circuit is converted into a digital voltage, thereby stably driving the first control switch circuit and the second control switch circuit to close, realizing the sound alarm and photoelectric signal alarm when the ambient temperature of the motor is too high.

[0018] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0019] Figure 1This is the circuit diagram for the controlled alarm circuit.

[0020] Figure 2 This is the circuit diagram for the temperature detection circuit.

[0021] Figure 3 This is a circuit diagram of the motor drive circuit and the power supply processing circuit. Detailed Implementation

[0022] To make the technical means, creative features, achieved objectives and functions of this utility model clearer and easier to understand, the utility model will be further described below with reference to the accompanying drawings and specific embodiments:

[0023] like Figures 1 to 3 As shown, a DCS system monitoring device for a submerged arc furnace includes: a power processing circuit, a control circuit, a motor drive circuit REL1, a temperature detection circuit, and a control-type alarm circuit. External high-voltage AC power supplies power to the motor M1 in the submerged arc furnace through the motor drive circuit REL1. The control terminal of the motor drive circuit REL1 is connected to the output terminal of the control circuit. The external high-voltage AC power is connected to the input terminal of the power processing circuit, which converts the external high-voltage AC power into DC voltage. A temperature sensor RT1 is installed in the temperature detection circuit, located on the casing of the motor M1 in the submerged arc furnace. The output terminal OUT1 of the temperature detection circuit is connected to the input terminal of the control circuit through an AD conversion circuit (which can be an AD conversion chip). The alarm circuit includes: a sound alarm unit BUZ1, a first control switch circuit, a first judgment execution circuit, a photoelectric alarm unit D2, a second control switch circuit, and a second judgment execution circuit. The power supply circuit output VCC (outputting 5V voltage) powers the sound alarm unit BUZ1 through the first control switch circuit, and the power supply circuit output VCC powers the photoelectric alarm unit D2 through the second control switch circuit. The input terminals of the first and second judgment execution circuits are both connected to the output terminal OUT1 of the temperature detection circuit. The output terminal of the first judgment execution circuit is connected to the control terminal of the first control switch circuit, and the output terminal of the second judgment execution circuit is connected to the control terminal of the second control switch circuit.

[0024] In the above structure, the control circuit can be a minimum system made with AT89C51, but other control chips can also be used.

[0025] The smallest system composed of pieces.

[0026] Preferably, since the external high-voltage AC power is 380V (or 220V), the motor drive circuit REL1 uses a relay with at least three normally closed switches; a contactor can also be used. This allows the motor drive circuit REL1 to close under the control of the digital signal output control circuit, thus controlling the operation of motor M1. The external high-voltage AC power is connected to the three phases L1, L2, and L3 in the diagram.

[0027] In this embodiment, the first end of the relay coil is connected to the output terminal of the power processing circuit, the second end of the relay coil is connected to the collector of transistor Q1, the emitter of transistor Q1 is grounded, and the base of transistor Q1 is the control terminal of motor drive circuit REL1.

[0028] In this embodiment, both the first and second controllable switching circuits include a transistor Q4. Of course, MOSFETs, relays, etc. can also be used, but transistors and MOSFETs are cheaper.

[0029] In this embodiment, both the first and second judgment execution circuits include a current limiting module, a comparison module, and a reference voltage module. The input terminal of the current limiting module is either the input terminal of the first or second judgment execution circuit, and its output terminal is connected to the voltage input terminal of the comparison module. The output terminal VCC of the power processing circuit supplies power to the reference voltage module, and its output terminal is connected to the reference input terminal of the comparison module. The output terminal of the comparison module is either the output terminal of the first or second judgment execution module. Since both the first and second judgment execution circuits are connected to the output terminal OUT1 of the temperature detection circuit, current needs to flow from the output terminal OUT1 of the temperature detection circuit to the first judgment execution circuit and from the output terminal OUT1 of the temperature detection circuit to the second judgment execution circuit. If the voltage of the second judgment execution circuit is too high, it will cause the voltage to flow to the first judgment execution circuit, resulting in mutual interference. Therefore, a current limiting module is designed to limit the current flow and avoid mutual interference between the first and second judgment execution circuits. The comparison module directly converts the analog voltage output by the temperature detection circuit into a digital voltage output, while the reference voltage module provides the basis for judgment.

[0030] In this embodiment, the current limiting module includes a diode D1, with the anode of diode D1 serving as the input terminal and the cathode of diode D1 serving as the output terminal. Diode D1 is responsible for current limiting.

[0031] In this embodiment, the comparison module includes: comparator U2, the non-inverting input terminal of comparator U2 is the voltage input terminal of the comparison module, and the inverting input terminal of comparator U2 is the reference input terminal of the comparison module.

[0032] As a preferred option, comparator U2 can be an LM384, but other models can also be selected.

[0033] In this embodiment, the reference voltage module includes: a resistor R8 and a sliding resistor RV1. The first end of the resistor R8 is connected to the output terminal VCC of the power processing circuit, the second end of the resistor R8 is connected to the first stationary end of the sliding resistor RV1, the second stationary end of the sliding resistor RV1 is grounded, and the movable end of the sliding resistor RV1 is connected to the second stationary end of the sliding resistor RV1.

[0034] The first stationary terminal of RV1 is the output terminal of the reference voltage module. Resistor R8 and the sliding resistor RV1 form a voltage divider, and the voltage obtained after the divider is the required voltage.

[0035] The required reference voltage is provided to the comparison module to determine whether the maximum permissible temperature can be accommodated by adjusting the connection resistance of the sliding resistor RV1. Of course, if the required resistance value is already known, a resistor with a fixed resistance value can be selected to replace the sliding resistor RV1.

[0036] In this embodiment, the temperature detection circuit includes a detection execution module and a two-stage amplification module. The circuit containing the temperature sensor RT1 is the detection execution module. The output terminal of the detection execution module is connected to the output terminal of the two-stage amplification module, which is the output terminal OUT1 of the temperature detection circuit. The power supply circuit supplies power to the detection execution module and the two-stage amplification module. Since a temperature change of one degree may cause a very small voltage change, a current limiting module is added to the first and second judgment execution circuits. Therefore, the voltage change at the input of the comparison module is even smaller. Thus, the two-stage amplification module is designed to amplify the voltage, enabling the comparison module to determine temperature changes with higher accuracy.

[0037] In this embodiment, the detection execution module includes a resistor R1. The first terminal of resistor R1 is connected to the first terminal of temperature sensor RT1, and the second terminal of temperature sensor RT1 is connected to the output terminal VCC of the power processing circuit. The second terminal of resistor R1 is grounded, and the first terminal of resistor R1 is the output terminal of the detection execution module. Resistor R1 and temperature sensor RT1 form the detection execution module, a detection circuit. When the temperature changes, the voltage at the connection point between resistor R1 and temperature sensor RT1 changes, thereby detecting this change and enabling temperature detection.

[0038] In this embodiment, the temperature sensor RT1 is an NTC type. As the temperature increases, the resistance of the temperature sensor RT1 decreases, and the voltage across the temperature sensor RT1 and resistor R1 increases. This results in a higher voltage at the output terminal OUT1 of the temperature detection circuit. When the voltage at the non-inverting input terminal of comparator U2 is higher than the voltage at the inverting input terminal, the output voltage of comparator U2 will increase from low to high. Alternatively, the temperature sensor RT1 can also be a PTC type. However, as the temperature increases, the resistance of the temperature sensor RT1 decreases, requiring the positions of resistor R1 and the temperature sensor RT1 to be swapped.

[0039] In this embodiment, the power processing circuit includes a transformer module, a rectifier module, and a step-down regulator module. The input terminal of the transformer module is connected to an external high-voltage AC power supply, the output terminal of the transformer module is connected to the input terminal of the rectifier module, and the output terminal of the rectifier module is connected to the output terminal of the step-down regulator module.

[0040] As mentioned above, the transformer module can use transformer TR1. Transformer TR1 is connected to the external high-voltage AC power. Transformer TR1 has the functions of adjusting phase and stepping down voltage, which can protect the rectifier module and extend its service life.

[0041] In this embodiment, the rectifier module adopts a diode rectifier bridge, the step-down regulator module adopts a step-down chip U1, the step-down chip U1 adopts the 7812 model, of course other models can also be used, and capacitors C2 and C1 are used for voltage regulation.

[0042] The two-stage amplifier module includes: resistors R2, R3, R4, R5, R6, and R7; amplifying transistors Q2 and Q3; capacitors C3, C4, C5, and C6. The positive terminal of capacitor C3 is the input terminal of the two-stage amplifier module, and the negative terminal of capacitor C3 is connected to the first terminal of resistor R3. The second terminal of resistor R3 is grounded.

[0043] The first terminal of resistor R2 is connected to the first terminal of resistor R3, and the second terminal of resistor R2 is connected to the output terminal of the power supply processing circuit.

[0044] The output of the circuit is connected to the first terminal of resistor R4, the first terminal of resistor R6, and the collector of transistor Q3. The first terminal of resistor R3 is connected to the base of transistor Q2. The collector of transistor Q2 is connected to the second terminal of resistor R4 and the positive terminal of capacitor C5. The emitter of transistor Q2 is connected to the first terminal of resistor R5 and the positive terminal of capacitor C4. The negative terminal of capacitor C4 is grounded. The second terminal of resistor R5 is grounded. The negative terminal of capacitor C5 is connected to the second terminal of resistor R6 and the base of transistor Q3. The emitter of transistor Q3 is connected to the first terminal of resistor R7 and the positive terminal of capacitor C6. The negative terminal of capacitor C6 and the second terminal of resistor R7 are grounded. The first terminal of resistor R7 is the output terminal of the dual-stage amplification module. Resistor R2 is connected to the base of transistor Q2, raising the voltage output of the temperature detection circuit. Subsequently, transistors Q2 and Q3 perform two amplifications.

[0045] The aforementioned dual-stage amplification module can also be made using two amplifier chips, and is not limited to the above implementation method.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A monitoring device for a DCS system of a submerged arc furnace, characterized in that, include: Power supply circuit, control circuit, motor drive circuit, temperature detection circuit, and controllable alarm circuit; External high-voltage AC power supplies power to the motor in the electric arc furnace through the motor drive circuit, and the control terminal of the motor drive circuit is connected to the output terminal of the control circuit. The external high-voltage AC power is connected to the input terminal of the power processing circuit, which is used to convert the external high-voltage AC power into DC voltage. The temperature detection circuit is equipped with a temperature sensor RT1, which is located on the motor casing in the electric arc furnace. The output terminal OUT1 of the temperature detection circuit is connected to the input terminal of the control circuit through an AD conversion circuit. The controllable alarm circuit includes: an audible alarm unit, a first controllable switch circuit, a first judgment execution circuit, a photoelectric alarm unit, a second controllable switch circuit, and a second judgment execution circuit. The output terminal of the power processing circuit supplies power to the audible alarm unit through the first controllable switch circuit, and the output terminal of the power processing circuit supplies power to the photoelectric alarm unit through the second controllable switch circuit. The input terminals of the first and second judgment execution circuits are both connected to the output terminal OUT1 of the temperature detection circuit. The output terminal of the first judgment execution circuit is connected to the control terminal of the first controllable switch circuit, and the output terminal of the second judgment execution circuit is connected to the control terminal of the second controllable switch circuit.

2. The monitoring device for a DCS system of a submerged arc furnace according to claim 1, characterized in that, Both the first and second judgment execution circuits include: a current limiting module, a comparison module, and a reference voltage module. The input terminal of the current limiting module is the input terminal of either the first or second judgment execution circuit. The output terminal of the current limiting module is connected to the voltage input terminal of the comparison module. The output terminal of the power processing circuit supplies power to the reference voltage module. The output terminal of the reference voltage module is connected to the reference input terminal of the comparison module. The output terminal of the comparison module is the output terminal of either the first or second judgment execution module.

3. The monitoring device for a DCS system of a submerged arc furnace according to claim 2, characterized in that, The current limiting module includes a diode D1, with the anode of diode D1 serving as the input terminal and the cathode of diode D1 serving as the output terminal.

4. The monitoring device for a DCS system of a submerged arc furnace according to claim 3, characterized in that, The comparison module includes: comparator U2, the non-inverting input of comparator U2 is the voltage input of the comparison module, and the inverting input of comparator U2 is the reference input of the comparison module.

5. A monitoring device for a DCS system of a submerged arc furnace according to claim 4, characterized in that, The reference voltage module includes a resistor R8 and a sliding resistor RV1. The first terminal of resistor R8 is connected to the output terminal of the power processing circuit, and the second terminal of resistor R8 is connected to the first stationary terminal of sliding resistor RV1. The second stationary terminal of sliding resistor RV1 is grounded, and the movable terminal of sliding resistor RV1 is connected to the second stationary terminal. The first stationary terminal of sliding resistor RV1 is the output of the reference voltage module. end.

6. A monitoring device for a DCS system of a submerged arc furnace according to any one of claims 2 to 5, characterized in that, The temperature detection circuit includes a detection execution module and a two-stage amplification module. The circuit containing the temperature sensor RT1 is the detection execution module. The output of the detection execution module is connected to the output of the two-stage amplification module. The output of the two-stage amplification module is the output OUT1 of the temperature detection circuit. The power supply circuit supplies power to the detection execution module and the two-stage amplification module.

7. A monitoring device for a DCS system of a submerged arc furnace according to claim 6, characterized in that, The detection execution module includes: a resistor R1, the first end of which is connected to the first end of a temperature sensor RT1, the second end of which is connected to the output of a power processing circuit, the second end of which is grounded, and the first end of which is the output of the detection execution module.

8. A monitoring device for a DCS system of a submerged arc furnace according to claim 6, characterized in that, The power supply processing circuit includes: a transformer module, a rectifier module, and a step-down regulator module. The input terminal of the transformer module is connected to the external high-voltage AC power, the output terminal of the transformer module is connected to the input terminal of the rectifier module, and the output terminal of the rectifier module is connected to the output terminal of the step-down regulator module.

Images