A pressure regulator for a synthetic heating furnace and a control system including the same.

Abstract

This application discloses a voltage regulator for a synthesis heating furnace and a control system including the same. The voltage regulator includes a digital signal processor and a target signal input module for inputting a target electrical signal and transmitting it to the digital signal processor. The digital signal processor generates a control signal based on the target electrical signal and sends it to the control trigger terminal of a thyristor component. The thyristor component includes a three-phase thyristor switch. After receiving the control signal, each phase thyristor switch performs an on or off operation to adjust the input voltage of the synthesis heating furnace. A feedback signal receiving module receives the actual electrical signal from the synthesis heating furnace and sends it to the digital signal processor. The digital signal processor adjusts the control signal based on the difference between the actual electrical signal and the target electrical signal. The solution of this application can effectively improve the accuracy of the voltage regulation result of the voltage regulator.

Description

Technical Field

[0001] This application relates to the field of control equipment technology for heating furnaces, and particularly to a pressure regulator for a synthesis heating furnace and a control system including the same. Background Technology

[0002] In the chemical industry, many process production lines utilize heating furnaces, such as melting, holding, annealing, and heating. To meet the demands of these production lines, voltage regulators are used to control the heating furnaces. Currently, these regulators use analog controllers to control the on / off state of thyristors in the three-phase circuit, thereby controlling the on / off state of the heating element and changing its temperature. However, existing solutions using analog controllers to adjust the thyristors have low control accuracy, resulting in unbalanced three-phase output currents and easily damaging the power unit thyristors and the heating element. Summary of the Invention

[0003] The technical problem to be solved by this application is the poor accuracy of existing pressure regulators for heating furnaces. To this end, this application proposes a pressure regulator for a synthesis heating furnace and a control system including the regulator.

[0004] This application provides a pressure regulator for a synthesis heating furnace, including a digital signal processor, and:

[0005] A target signal input module is used to input a target electrical signal and transmit the target electrical signal to the digital signal processor;

[0006] The digital signal processor is used to generate a control signal based on the target electrical signal and send the control signal to the control trigger terminal of the thyristor component.

[0007] The thyristor assembly includes a three-phase thyristor switch. After receiving the control signal, the thyristor assembly performs the operation of turning on or off each phase of the thyristor switch to adjust the input voltage of the synthesis heating furnace.

[0008] The feedback signal receiving module is used to receive the actual electrical signal of the synthesis heating furnace and send the actual electrical signal to the digital signal processor;

[0009] The digital signal processor adjusts the control signal based on the difference between the actual electrical signal and the target electrical signal.

[0010] The pressure regulator of the synthesis furnace described in some schemes also includes:

[0011] The current transformer includes three current transformers, each of which is connected to the circuit containing a silicon controlled rectifier switch.

[0012] The current transformer is used to monitor the loop current and disconnect the loop when the loop current exceeds a set threshold.

[0013] In some embodiments, the pressure regulator of the synthesis heating furnace includes a target signal input module comprising a touch screen and a potentiometer; the touch screen is also used to display the target electrical signal, the control signal, and the operating status of the pressure regulator.

[0014] In some embodiments of the synthesis heating furnace, the target signal input module is further used to send a start signal and a stop signal to the digital signal processor; the start signal is used to increase the control signal output by the digital signal processor from zero to 100% at a set rate, and the stop signal is used to decrease the control signal output by the digital signal processor from 100% to zero at a set rate.

[0015] The pressure regulator of the synthesis furnace described in some schemes also includes:

[0016] The load detection circuit is used to detect whether the load connected to the digital signal processor is greater than the set load. If the connected load is greater than the set load, an overload signal is output.

[0017] An alarm relay is connected to the output terminal of the load detection circuit. After receiving the overload signal, the alarm relay outputs an overload alarm signal.

[0018] In some solutions, the voltage regulator of the synthesis heating furnace is a three-phase air-cooled thyristor assembly, and the electrical clearance between thyristor switches of different phases is not less than 20mm.

[0019] In some embodiments of the synthesis heating furnace, the voltage regulator of the thyristor assembly further includes a temperature sensor, which monitors the temperature value of each phase thyristor switch and generates a high-temperature signal if the temperature value exceeds a set temperature threshold.

[0020] A temperature alarm circuit, the input of which is connected to the temperature sensor, issues a high temperature alarm signal after receiving the high temperature signal.

[0021] Some embodiments of this application also provide a control system, including a pressure regulator for the synthesis heating furnace described in any of the above solutions, and further comprising:

[0022] A transformer is used to output a power signal of a set magnitude.

[0023] The power supply cabinet is connected to the transformer, receives the power signal, and provides power to the voltage regulator after stabilizing the power signal.

[0024] In some solutions, the control system includes a power supply cabinet comprising a universal circuit breaker connected in series with the output terminal of the transformer.

[0025] The control system described in some of the solutions also includes:

[0026] The DCS control module is connected to the voltage regulator.

[0027] The technical solution of this application has the following technical advantages over the prior art:

[0028] The pressure regulator and control system of the synthesis heating furnace provided in this application are controlled by a digital signal processor, which offers higher control precision compared to analog controllers. A target electrical signal is input via a target signal input module, and trigger control is achieved using a thyristor component, resulting in precise control and balanced three-phase output, thus comprehensively improving control precision, stability, reliability, and linearity. The digital signal processor can also receive the actual electrical signal from the synthesis heating furnace and adjust the control signal based on the difference between the actual and target electrical signals, forming feedback control and further enhancing the accuracy of the pressure regulator's adjustment results. Attached Figure Description

[0029] The preferred embodiments of this application will be described in detail below with reference to the accompanying drawings, which will help to understand the purpose and advantages of this application, wherein:

[0030] Figure 1 This is a structural block diagram of the pressure regulator of the synthesis heating furnace according to one embodiment of this application;

[0031] Figure 2 This is a structural block diagram of the pressure regulator of the synthesis heating furnace according to another embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the circuit design structure of the control panel of the voltage regulator according to one embodiment of this application;

[0033] Figure 4 This is a structural block diagram of a control system including a pressure regulator for a synthesis heating furnace according to one embodiment of this application;

[0034] Figure 5 for Figure 4 A schematic diagram of the external appearance of the control system shown;

[0035] Figure 6 for Figure 5 A schematic diagram of the internal structure of each device in the control system shown. Detailed Implementation

[0036] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0040] This embodiment provides a pressure regulator for a synthesis heating furnace, such as... Figure 1 As shown, the system includes a digital signal processor 100, a target signal input module 101, a thyristor assembly 102, and a feedback signal receiving module 103. The target signal input module 101 is used to input a target electrical signal and transmit it to the digital signal processor. The digital signal processor 100 is used to generate a control signal based on the target electrical signal and send the control signal to the control trigger terminal of the thyristor assembly 102. The thyristor assembly 102 includes a three-phase thyristor switch. After receiving the control signal, each phase thyristor switch performs an on / off operation to adjust the input voltage of the synthesis heating furnace 20. The feedback signal receiving module 103 is used to receive the actual electrical signal from the synthesis heating furnace and send it to the digital signal processor 100. The digital signal processor 100 adjusts the control signal based on the difference between the actual electrical signal and the target electrical signal.

[0041] The above-described scheme of this application uses a digital signal processor 100 for control, which offers higher control precision compared to analog controllers. By using the target signal input module 101 to input the target electrical signal and the thyristor component 102 to achieve trigger control, it offers advantages such as precise control and balanced three-phase output, achieving a comprehensive improvement in control precision, stability, reliability, and linearity. The digital signal processor 100 can also receive the actual electrical signal from the synthesis heating furnace through the feedback signal receiving module 103, and adjust the control signal based on the difference between the actual electrical signal and the target electrical signal, forming feedback control and improving the accuracy of the voltage regulator's voltage regulation result.

[0042] Furthermore, the pressure regulator of the synthesis heating furnace described in the above scheme, such as Figure 2 As shown, it also includes three current transformers 104, each of which is connected to the circuit containing a thyristor switch. The current transformer 104 monitors the circuit current and disconnects the circuit when the circuit current exceeds a set threshold. That is, the current transformer 104 provides overcurrent protection and phase loss protection identification functions, ensuring the safety of the voltage regulator during operation.

[0043] In some embodiments, the voltage regulator may further include a load detection circuit 105 for detecting whether the load connected to the digital signal processor 100 is greater than a set load, and outputting an overload signal if the connected load is greater than the set load; and an alarm relay 106 connected to the output terminal of the load detection circuit 105, which outputs an overload alarm signal after receiving the overload signal.

[0044] like Figure 3 As shown, in the above scheme, the digital signal processor 100 can be selected as a mainstream industrial dedicated 32-bit DSP digital signal processor. It adopts digital synchronization and pulse forming technology, resulting in high phase shift accuracy. Terminals 1-3 serve as the operating power input terminals; terminals 1 and 3 connect to a 380V power supply, and terminals 2 and 3 connect to a 220V power supply. In practical applications, only one power supply needs to be connected, with 380V being preferred. Terminals 4 and 5 connect to the CT1 current transformer connection terminal, corresponding to U-phase current monitoring; terminals 6 and 7 connect to the CT2 current transformer connection terminal, corresponding to V-phase current monitoring; and terminals 8 and 9 connect to the CT3 current transformer connection terminal, corresponding to W-phase current monitoring. Terminals 10 and 11 connect to the constant current feedback input signal, and terminals 12 and 13 connect to the constant voltage feedback input signal.

[0045] Preferably, the target signal input module 101 includes a touch screen and a potentiometer; the touch screen is also used to display the target electrical signal, the control signal, and the operating status of the voltage regulator. Figure 3In the 32-bit DSP digital signal processor, terminals 14, 15, and 16 are connected to potentiometers, which can be 10K 2W potentiometers. Terminals 17, 18, and 19 are connected to the common terminal and the start / stop control terminal. When the start mode is self-locking, shorting 17 and 18 starts the operation, and opening them stops it. When the start mode is jogging, connecting 17 and 18 starts the operation, and connecting 17 and 19 stops it. If a touchscreen is connected, terminal 20 can be used to connect to the LCD touchscreen. Additionally, terminals 21, 22, and 23 of the 32-bit DSP are connected to RS485 communication terminals. Terminal 24 serves as the emergency stop input terminal; shorting terminals 17 and 24 performs an emergency stop operation. Terminal 25 is the reset terminal; shorting terminals 17 and 25 allows the voltage regulator to perform a system reset operation. Terminal 26 is the overheat input terminal for the SCR, which can be implemented using a normally open temperature control switch. The other end of the temperature control switch is connected to terminal 17. When the temperature control switch detects that the SCR switch temperature is too high, it can automatically shut down the machine. Terminals 27, 28, and 29 are the output terminals of the running relay. Terminal 27 is normally open, terminal 28 is a common terminal, and terminal 29 is a normally closed terminal. Terminals 30, 31, and 32 are the output terminals of the fault relay. Terminal 30 is normally open, terminal 31 is a common terminal, and terminal 32 is a normally closed terminal. Terminals 36, 37, 38, and 39 are the control trigger terminals for the W-phase SCR. Terminals 40, 41, 42, and 43 are the control trigger terminals for the V-phase SCR. Terminals 44, 45, 46, and 47 are the trigger terminals for the W-phase SCR. Terminals 48, 49, and 50 correspond to the main circuit power synchronization signal input terminals, where terminal 48 corresponds to the W-phase, terminal 49 corresponds to the V-phase, and terminal 50 corresponds to the U-phase.

[0046] Preferably, the target signal input module 101 in the above scheme is further used to send a start signal and a stop signal to the digital signal processor; the start signal is used to increase the control signal output by the digital signal processor from zero to 100% at a set rate, and the stop signal is used to decrease the control signal output by the digital signal processor from 100% to zero at a set rate. That is, soft start and soft stop are adopted; soft start can eliminate the impact on the power grid and itself when the load is running, and soft stop can eliminate the impact on the power grid and itself when the load stops.

[0047] In some designs, the thyristor assembly is a three-phase air-cooled assembly, and the electrical clearance between thyristor switches of different phases is not less than 20mm. Specifically, the thyristor AC voltage regulator is a three-phase air-cooled type with a rated voltage of 380V and an output current of 320A. The electrical clearance of not less than 20mm ensures that the voltage regulator is safe, reliable, easy to operate, and easy to maintain.

[0048] More preferably, the thyristor assembly further includes a temperature sensor for monitoring the temperature value of each phase of the thyristor switch. If the temperature value exceeds a set temperature threshold, a high-temperature signal is generated. A temperature alarm circuit, whose input is connected to the temperature sensor, issues a high-temperature alarm signal upon receiving the high-temperature signal. In this solution, the thyristor switch uses a thyristor transistor, is air-cooled, and is equipped with temperature monitoring to ensure the stability of the thyristor switch.

[0049] This application provides a control system, such as... Figures 4-6 As shown, the system includes a voltage regulator for the synthesis heating furnace, a transformer 10 for outputting a power signal of a set magnitude, and a power cabinet 11 connected to the transformer 10. The power cabinet receives the power signal, stabilizes it, and then supplies power to the voltage regulator 13. In this design, the transformer 10 outputs 0.4kV power to the power cabinet 11. The power cabinet 11 contains a universal circuit breaker connected in series with the output of the transformer to provide a stable power supply to the voltage regulator 13. The universal circuit breaker also features instantaneous trip and overload protection. The voltage regulator 13 has dual closed-loop PID automatic adjustment functions for constant voltage and current regulation and constant current and voltage regulation. The voltage regulation function is implemented using a thyristor, and it is air-cooled with temperature monitoring. Online ground insulation monitoring of the furnace heating elements is configured, and an alarm and protection mechanism is established. The voltage regulator 13 employs digital synchronization and pulse forming technology, achieving high phase shift accuracy, precise control via thyristor triggering, and balanced three-phase output. The touch screen 14 and the voltage regulator 13 can communicate bidirectionally. Equipped with RS485 and Modbus communication interfaces, it can achieve network communication with the integrated automation system, monitor the operating status of the equipment online, and independently modify the operating parameters or control mode.

[0050] Preferably, the control system further includes a DCS control module 12, which is connected to the power cabinet 11 and the voltage regulator 13.

[0051] by Figures 4-6 Taking the control system shown as an example, other signals or installation requirements may also include:

[0052] (1) The voltage regulator has an output power of 2500kW, an output voltage of 0-380V, and an output current of 0-3200A. The main functions of the voltage regulator are: heater start-up control; heater stop control (including anti-dry-burning stop control, overcurrent protection, and medium flow prevention); voltage and current indication; electric heater power adjustment; manual adjustment; and DCS regulation. The voltage regulator outputs a current signal to the DCS, signal type 4-20mA; the DCS outputs a regulation signal to the power control cabinet, signal type 4-20mA; the voltage regulator outputs an electric heater operating status signal to the DCS, normally open contact (1 for running); and the voltage regulator outputs an electric heater stop status signal to the DCS, normally open contact (0 for stopped).

[0053] (2) The voltage regulator adopts a 32-bit industrial-grade high-speed microprocessor, touch screen Chinese menu operation, and fully automatic SMD process manufacturing, ensuring stable and reliable performance; it has digital constant current and constant voltage functions as well as current limiting and voltage limiting functions, providing precise control of the load, and overcurrent and overvoltage abnormal protection functions; it has comprehensive fault detection and alarm functions, real-time detection of load status, load current, control signal, feedback signal loss, and other parameters; overload protection: after startup, it begins to judge whether the load is overloaded, and stops operation after the set protection time for continuous overload, while simultaneously outputting an alarm relay; soft start: during startup, the output voltage will gradually increase from zero to 100% to eliminate the impact on the power grid and itself during load operation, soft The start-up time parameter is configurable; soft shutdown: when stopping, the output voltage gradually decreases from 100% to zero to eliminate the impact on the power grid and itself when the load stops, and the soft shutdown time parameter is configurable; it has an automatic phase sequence identification function, and there are no phase sequence requirements for the power supply to the control board; it adopts an intrinsically safe design, and the control board has a protection design against burnout of the thyristor trigger interface, supporting multi-functional expansion boards for input and output; the thyristor drive interface has a double row of LED indicators, with a green light indicating whether the trigger board is faulty and a red light indicating whether the external control line is correct, allowing for quick checking of the error location; all output ports and switch input ports are electrically isolated, providing better electromagnetic interference protection. It also features short-circuit protection, overload protection, over-temperature protection, and power regulation functions.

[0054] (3) The voltage regulator is a three-phase air-cooled type with a rated voltage of 380V and an output current of 3200A.

[0055] (4) Voltage regulator control mode: power adjustment within the range of 0-100% can be achieved on DCS and touch screen to control temperature. Current and voltage are transmitted as 4-20mA signals to DSC display.

[0056] (4) All analog signals sent to the DCS should be 4-20mA DC, and all digital signals sent to the DCS should be passive dry contact signals without a common terminal. All signals sent to the DCS should be connected to the power control cabinet.

[0057] (5) The structure, electrical installation, and circuit layout of the voltage regulator must be safe, reliable, easy to operate, and easy to maintain. The electrical clearance between exposed live conductors and between live conductors and ground in the voltage regulator cabinet shall not be less than 20mm. The internal and external conductor terminals of the cabinet must meet the normal operating current and be able to withstand a short-circuit withstand current not less than that of the electrical components inside the cabinet. Sufficient effective space must be provided inside the cabinet for wiring. In a three-phase four-wire circuit, there must be a neutral wire and a ground wire. The voltage regulator shall be equipped with a "local / remote" selector switch, an ammeter, a start button, a stop button, and a run / stop / interlock indicator light. When the selector switch is switched to the local position, remote operation is invalid, and all requirements for local control are met; when the selector switch is switched to the remote position, local operation is invalid (except for emergency stop operation). All unused spare contacts of circuit breakers, contactors, relays, etc., inside the voltage regulator, except for those already used in the cabinet wiring, shall be led to the terminal block for possible on-site wiring modifications. The wiring terminals inside the voltage regulator shall have a 20% margin. Secondary wiring must be neat and aesthetically pleasing, with a cross-sectional area of ​​not less than 2.5 mm². Communication signals and control operations between the voltage regulator and the central control DCS include: electric heater operation signal (DI), 4-20mA input current, and output voltage signals. The final signals should include, but are not limited to, the above signals and should be routed to the terminal block.

[0058] Verification has shown that the control system of the above-mentioned solution fully meets the requirements for power and voltage regulation control of the 3200A heating furnace. Simultaneously, all control signals and non-electrical signals are displayed on the touchscreen, allowing for real-time adjustment. Interlocking alarms and protection mechanisms are also included to achieve precise adjustment and control.

[0059] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A pressure regulator for a synthesis heater, characterized by comprising a digital signal processor, and: a target signal input module, configured to input a target electrical signal and transmit the target electrical signal to the digital signal processor; the digital signal processor, configured to generate a control signal according to the target electrical signal and send the control signal to a control trigger end of a thyristor assembly; the digital signal processor is a 32-bit DSP digital signal processor adopting digital synchronization and pulse forming technology; the thyristor assembly comprises three-phase thyristor switches, and after receiving the control signal, each phase thyristor switch performs on-off operation to adjust the input voltage of a synthetic heating furnace; a feedback signal receiving module, configured to receive an actual electrical signal of the synthetic heating furnace and send the actual electrical signal to the digital signal processor; the digital signal processor adjusts the control signal according to a difference value between the actual electrical signal and the target electrical signal; the target signal input module is further configured to send a start signal and a stop signal to the digital signal processor; the start signal is used to make the control signal output by the digital signal processor start from zero and increase to 100% at a set rate, and the stop signal is used to make the control signal output by the digital signal processor decrease from 100% to zero at a set rate.

2. The pressure regulator of a synthesis heating furnace according to claim 1, characterized in that, Further comprising: three current transformers, each of which is connected to a loop in which a thyristor switch is located; the current transformer is configured to monitor loop current and disconnect the loop when the loop current is greater than a set threshold.

3. The voltage regulator of the synthetic heating furnace according to claim 1, wherein: the target signal input module comprises a touch screen and a potentiometer; the touch screen is further configured to display the target electrical signal, the control signal and the running state of the voltage regulator.

4. The pressure regulator for a synthesis heater furnace according to claim 1, wherein Further comprising: a load detection circuit, configured to detect whether a load connected to the digital signal processor is greater than a set load, and output an overload signal if the load is greater than the set load; an alarm relay connected to an output end of the load detection circuit, configured to output an overload alarm signal after receiving the overload signal.

5. The voltage regulator of the synthetic heating furnace according to any one of claims 1-4, wherein: the thyristor assembly is a three-phase air-cooled assembly, and the electrical gap of the thyristor switches in different phases is not less than 20 mm.

6. The voltage regulator of the synthetic heating furnace according to claim 5, wherein: the thyristor assembly further comprises a temperature sensor, configured to monitor the temperature value of each phase thyristor switch and generate a high-temperature signal if the temperature value is greater than a set temperature threshold; a temperature alarm circuit connected to the temperature sensor, configured to output a high-temperature alarm signal after receiving the high-temperature signal.

7. A control system characterized by, The voltage regulator of the synthetic heating furnace according to any one of claims 1-6 further comprises: a transformer, configured to output a power signal of a set size; a power supply cabinet connected to the transformer, configured to receive the power signal, perform voltage stabilization on the power signal and provide power for the voltage regulator.

8. The control system of claim 7, wherein: the power cabinet includes a circuit breaker, the circuit breaker being connected in series with the output of the transformer.

9. The control system of claim 8, wherein, further comprising: a DCS control module, the DCS control module being connected to the voltage regulator.

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