Optical fiber drawing furnace control system based on PLC

Abstract

The utility model discloses a PLC-based optical fiber drawing furnace control system, which comprises a PLC and a direct current power supply, the power output end of the direct current power supply is electrically connected with a heating body of an optical fiber drawing furnace, the PLC is electrically connected with the control end of the direct current power supply, and the power input end of the direct current power supply is used for being connected with an alternating current loop to supply power. The direct-current power supply outputs direct current. The direct-current power supply supplies power to the heating body of the optical fiber drawing furnace, and the current output by the direct-current power supply is always kept constant and is not influenced by the voltage fluctuation of a power grid, so that stable power supply can be provided for a load, and the output precision of the direct-current power supply is high, so that the heating control of the optical fiber drawing furnace is more stable; therefore, temperature fluctuation in the wire drawing process is reduced, and the quality of optical fibers is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical fiber production equipment control technical field especially, it is a kind of optical fiber drawing furnace control system based on PLC. BACKGROUND

[0002] As the core equipment in the optical fiber production process, the most important performance of the optical fiber drawing furnace is the control of the temperature in the furnace, and the accuracy and precision of temperature control directly determine the quality of optical fiber production.

[0003] Chinese patent document CN117417120A, published (announced) date: 2024.01.19, is a kind of optical fiber drawing furnace temperature control system and control method based on PLC disclosed by our company, including PLC controller, PLC controller is respectively with power regulation circuit, voltage and current sensor, high temperature probe, process gas control unit, cooling water control unit;PLC controller provides power for the drawing furnace body through power regulation circuit;High temperature probe is used to collect the temperature of the drawing furnace body;Voltage and current sensor is used to collect the heating body current, voltage signal of the drawing furnace body;Process gas control unit is used to provide protective gas to the drawing furnace body, cooling water control unit is used to provide cooling water to the outside of the drawing furnace body.Its advantages are: in the actual temperature control process, whether it is the heating process, or the cooling process, and the precision after temperature stabilization can be well controlled, and the purpose of accurate control of the temperature of the whole furnace is achieved.

[0004] But the power regulation circuit in the scheme converts the 380V power supply into the input power of the transformer, and adjusts the size of the transformer input voltage through the given current value to control the output voltage of the transformer, and then controls the power of the heating body in the drawing furnace.The shortcomings of this scheme are: in the power regulation circuit, the control of the transformer is realized by thyristor regulator, and the output of the thyristor is adjusted by PLC according to the temperature feedback by the temperature sensor to control the transformer, so as to stabilize the temperature, wherein the output accuracy of the thyristor is 0.01KW, which is difficult to realize the requirement of low temperature fluctuation for stable operation of part of the drawing furnace, and affects the quality of optical fiber. UTILITY MODEL CONTENTS

[0005] To solve the current technical problems, the main purpose of the utility model is to provide a kind of optical fiber drawing furnace control system based on PLC, the heating body on the optical fiber drawing furnace is powered by direct current power supply, the current output by direct current power supply always remains constant, is not affected by the voltage fluctuation of power grid, therefore can provide stable power supply for load, and the output accuracy of direct current power supply is high, makes the heating control of drawing furnace more stable, thereby reduces the fluctuation of temperature in the drawing process, ensures the quality of optical fiber.

[0006] The utility model discloses the technical scheme adopted is: a kind of optical fiber drawing furnace control system based on PLC, including PLC controller, still including direct current power supply, the power output end of direct current power supply is electrically connected with the heating body of optical fiber drawing furnace, and the control end of PLC controller is electrically connected with direct current power supply, and the power input end of direct current power supply is used to be connected with alternating current loop power supply, and direct current power supply outputs direct current.

[0007] The PLC controller is electrically connected with the first temperature sensor on the optical fiber drawing furnace.

[0008] The PLC controller is electrically connected with the first control valve of process gas control unit.

[0009] The PLC controller is electrically connected with the second control valve and the second temperature sensor of cooling water control unit.

[0010] The PLC controller is electrically connected with the first control panel.

[0011] The direct current power supply is electrically connected with the second control panel.

[0012] The utility model has the following beneficial effects:

[0013] The utility model discloses the heating body power supply of optical fiber drawing furnace by direct current power supply, and the current of direct current power supply output always keeps constant, is not influenced by power grid voltage fluctuation, can therefore provide stable power supply for load, and the output precision of direct current power supply is 0.001KW, makes the heating control of optical fiber drawing furnace more stable, thereby reducing the fluctuation of temperature in drawing process, guarantee the quality of optical fiber.And direct current power supply can feed back voltage, current, power to PLC by communication mode, reduces the error that the intermediate link can generate, makes the signal of feedback more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the specific embodiment of the utility model or the technical scheme in prior art, the following will be briefly introduced to the drawing needed to be used in specific embodiment or prior art description, obviously, the drawing in the following description is some embodiments of the utility model, for ordinary skilled person in the art, without creative labor, other drawings can also be obtained according to these drawings.

[0015] Figure 1 It is the control system schematic diagram of the utility model.

[0016] Reference numerals:

[0017] PLC controller 10, first control panel 11;

[0018] DC power supply 20, second control panel 21;

[0019] Optical fiber drawing furnace 30, heating body 31, first temperature sensor 32;

[0020] Process gas control unit 40, first control valve 41;

[0021] Cooling water control unit 50, second control valve 51, second temperature sensor 52. DETAILED DESCRIPTION

[0022] The technical solutions of the present application will be described clearly and completely in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0023] Embodiment 1:

[0024] Referring to Figure 1 The present application provides a PLC-based optical fiber drawing furnace control system, comprising a PLC controller 10, further comprising a DC power supply 20, the power output end of the DC power supply 20 is electrically connected with the heating body 31 of the optical fiber drawing furnace 30, the PLC controller 10 is electrically connected with the control end of the DC power supply 20, the power input end of the DC power supply 20 is used for connecting with the AC circuit for power supply, and the DC power supply 20 outputs DC power.

[0025] The DC power supply 20 supplies power to the heating body 31 of the optical fiber drawing furnace 30, the current output by the DC power supply 20 always remains constant and is not affected by the voltage fluctuation of the power grid, so that stable power supply can be provided for the load, and the output accuracy of the DC power supply is 0.001KW, which makes the heating control of the optical fiber drawing furnace 30 more stable, thereby reducing the temperature fluctuation in the drawing process and ensuring the quality of the optical fiber.

[0026] And the DC power supply can feed back the voltage, current and power to the PLC through communication, reducing the error that may be generated by the intermediate link and making the feedback signal more accurate.

[0027] In the present embodiment, the DC power supply 20 adopts the DC power supply of Sichuan Yingjie Electrical Co., Ltd., model DDY10-40 / 750-T4 / F01, output power 30kW (40V / 750A). When the PLC fails or the current exceeds the set upper limit, the DC power supply 20 automatically stops.

[0028] The PLC controller 10 adopts 220V AC power supply.

[0029] Further, the PLC controller 10 is electrically connected with a first temperature sensor 32 on the fiber drawing furnace 30, the first temperature sensor 32 is used for measuring the temperature inside the fiber drawing furnace 30 and transmitting the temperature data to the PLC controller 10, so as to detect the temperature inside the fiber drawing furnace 30 in real time.

[0030] The PLC controller 10 is electrically connected with a first control valve 41 of the process gas control unit 40, and is used for controlling the opening and closing of the first control valve 41.

[0031] The PLC controller 10 is electrically connected with a second control valve 51 and a second temperature sensor 52 of the cooling water control unit 50, and is used for controlling the opening and closing of the second control valve 51 and measuring the temperature of the cooling water through the second temperature sensor 52.

[0032] The process gas control unit 40 is used for providing the protective gas to the fiber drawing furnace 30, and the cooling water control unit 50 is used for providing the cooling water to the furnace body of the fiber drawing furnace 30.

[0033] In use, the opening and closing of the first control valve 41 is controlled by the PLC controller 10, so as to realize the on-off of the protective gas. The opening and closing of the second control valve 51 is controlled by the PLC controller 10, so as to realize the opening and closing of the cooling water. The temperature of the cooling water is detected in real time through the second temperature sensor 52, and when the temperature of the cooling water exceeds a threshold value, the direct current power supply 20 is controlled to be closed by the PLC controller 10.

[0034] The first control valve 41 and the second control valve 51 adopt two-position two-way electromagnetic valves. The first temperature sensor 32 adopts a PT1000 temperature sensor, and the second temperature sensor 52 adopts a PT100 temperature sensor, and the second temperature sensor 52 is installed on a water return pipeline. In use, the first control valve 41, the second control valve 51, the first temperature sensor 32 and the second temperature sensor 52 are respectively electrically connected with the PLC controller 10.

[0035] In order to facilitate the operation of the PLC controller 10, the PLC controller 10 is electrically connected with a first control panel 11.

[0036] Further, the direct current power supply 20 is electrically connected with a second control panel 21, and the second control panel 21 is used for checking the running and fault information of the direct current power supply.

[0037] The first control panel 11 and the second control panel 21 can adopt touch screens.

[0038] The working principle of the utility model is as follows:

[0039] The current output by the DC power supply 20 remains constant and is not affected by fluctuations in the grid voltage, so it can provide stable power supply for the load. The output accuracy of the DC power supply is 0.001KW, which makes the heating control of the drawing furnace more stable, thereby reducing the temperature fluctuations in the normal drawing process and ensuring the quality of the optical fiber. The DC power supply 20 can feed back the voltage, current and power to the PLC through communication, reducing the errors that may be caused by intermediate links and making the feedback signals more accurate. The DC power supply 20 can set an upper limit for the current, and when the current exceeds the upper limit, it can automatically cut off the output to avoid the situation that the PLC controller 10 cannot shut down in time due to excessive current, resulting in damage to the equipment.

[0040] The working principle of the DC power supply is based on the underlying quality of the converter and the reliability of the high-frequency switching elements. A simple DC power supply consists of four main components: input filter, bridge rectifier, boost converter and output filter. First, the input filter can effectively reduce power grid noise and mutual interference. Then, the smooth and complete DC obtained from the input AC power is rectified by the bridge rectifier. Next, the rectified DC is sent to the boost converter, and the required voltage and current level are achieved through the efficient conversion of the boost converter. Finally, the output is filtered by the output filter to remove residual noise and obtain stable DC.

[0041] The DC power supply has high energy efficiency and can better meet the requirements of energy saving and environmental protection compared to AC power supply. Since the DC power supply does not need to perform frequency conversion, it can reduce energy loss and energy waste during transmission.

[0042] Reduces energy loss during operation of the optical fiber drawing furnace.

[0043] The DC power supply can provide stable voltage output because it is subjected to rectification and filtering processing with little pulsation. This makes the current through the graphite furnace more stable, thereby making the temperature control of the graphite furnace more stable.

Claims

1. A PLC-based optical fiber drawing furnace control system comprising a PLC controller (10), characterized in that: The direct current power supply (20) is electrically connected with the heating body (31) of the optical fiber drawing furnace (30), the PLC controller (10) is electrically connected with the control end of the direct current power supply (20), the power input end of the direct current power supply (20) is used for being connected with an alternating current loop for power supply, and the direct current power supply (20) outputs direct current.

2. The PLC-based optical fiber drawing furnace control system according to claim 1, wherein: The PLC controller (10) is electrically connected with the first temperature sensor (32) on the optical fiber drawing furnace (30), and the first temperature sensor (32) is used for measuring the temperature inside the optical fiber drawing furnace (30).

3. The PLC-based optical fiber drawing furnace control system of claim 1, wherein: The PLC controller (10) is electrically connected with the first control valve (41) of the process gas control unit (40).

4. The PLC-based optical fiber drawing furnace control system of claim 1, wherein: The PLC controller (10) is electrically connected with the second control valve (51) and the second temperature sensor (52) of the cooling water control unit (50).

5. The PLC-based optical fiber drawing furnace control system of claim 1, wherein: The PLC controller (10) is electrically connected with the first control panel (11).

6. The PLC-based optical fiber drawing furnace control system of claim 1, wherein: The direct current power supply (20) is electrically connected with the second control panel (21).

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