Power supply and distribution system of self-adaptive enhanced ladle refining furnace

Abstract

The self-adaptive enhanced power supply and distribution system for the ladle refining furnace overcomes the defects in waste steel adding mode identification and smelting process control in the prior art, a 35kV power supply is connected to the high-voltage switch cabinet, the voltage transformer is arranged to detect voltage fluctuation, and the power supply and distribution system is connected with the high-voltage switch cabinet. A circuit breaker with a transformer and an electric reactor and a resistance-capacitance absorption device are configured, and the stability of a power supply system and intelligent control over the smelting process are achieved through the variable-gear enhanced electric reactor, the transformer and a corresponding overvoltage protection device. The smelting power factor of the ladle refining furnace is effectively improved, the smelting period is shortened, the electric energy quality fluctuation and the load impact are reduced, the balance degree of the input power in the furnace is ensured, and the method has important significance on stable smelting production of the enhanced ladle refining furnace.

Description

Technical Field

[0001] The utility model belongs to the technical field of power supply for refining furnaces in the metallurgical industry, and particularly relates to a power supply and distribution system for an adaptive enhanced ladle refining furnace. Background Art

[0002] In the iron and steel metallurgical industry, as an important hub connecting the electric arc furnace or converter and the continuous casting machine, the operating state of the ladle refining furnace has a crucial impact on the stability of the entire system. The main function of the ladle refining furnace is to perform secondary refining on molten steel to improve the quality and purity of molten steel. However, in the actual smelting production process, the refining furnace faces various challenges, especially the problems related to the scrap charging method and its state identification.

[0003] Currently, there are mainly three ways to charge scrap into the ladle refining furnace: The first way is to directly add un-preheated scrap into the ladle when the electric arc furnace or converter taps, and then send the ladle into the refining furnace for heating. This method is simple and easy to operate, but it poses high requirements for the heating efficiency of the refining furnace and the temperature control of molten steel. The second way is to add scrap into the ladle for pure oxygen combustion preheating before the molten steel of the electric arc furnace or converter enters the ladle. The preheating temperature can reach 800°C - 1000°C, and then it is sent into the refining furnace. This method can improve the melting speed of scrap, but a large amount of energy is consumed during the preheating process. The third way is to use the high-temperature flue gas in the refining furnace to preheat the scrap online during the heating process of the refining furnace and continuously add it into the refining furnace for smelting. This method can effectively utilize the heat of the refining furnace and improve the energy utilization efficiency, but it poses high requirements for the charging timing and speed control of scrap.

[0004] However, the existing ladle refining furnaces cannot well handle the above different scrap charging methods during smelting. Due to the inability to accurately distinguish the state of scrap, the voltage and current fluctuations during the smelting process are large. At the same time, the source of scrap raw materials has great randomness, resulting in a large change in the load impact during melting of the refining furnace, causing great interference to the power quality of the power grid. In addition, operators usually rely on experience for manual observation. This method not only has errors, but also has large interference fluctuations to the electrode current, further exacerbating the three-phase power imbalance problem of the power system.

[0005] These factors act together, resulting in unbalanced melting power in the refining furnace, lag in electrode power regulation, and an extended smelting cycle of the refining furnace. In addition, the refractory materials on the furnace wall are also unevenly eroded, seriously affecting the stable smelting production of the refining furnace. Therefore, how to accurately identify the scrap charging method and adjust the smelting parameters according to different methods has become a key issue for improving the operation stability and smelting efficiency of the refining furnace. Summary of the Invention

[0006] To solve the above problems, the utility model provides a power supply and distribution system for an adaptive enhanced ladle refining furnace, aiming to improve the smelting power factor of the refining furnace, shorten the smelting cycle, reduce the power quality fluctuation and load impact through real-time monitoring and intelligent control, so as to ensure the balance of the input power in the furnace and achieve stable and efficient smelting production.

[0007] The technical solution adopted by the utility model is as follows:

[0008] A power supply and distribution system for an adaptive enhanced ladle refining furnace, characterized in that:

[0009] It includes a 35kV power supply. The 35kV power supply is connected to the 35kV bus through an incoming line isolating trolley. The 35kV bus is also respectively connected with a trolley voltage transformer, a transformer circuit breaker, and a circuit breaker with a reactor. The other end of the transformer circuit breaker is sequentially connected with a first resistor-capacitor absorption device, a transformer disconnector, a variable-ratio enhanced transformer, and an enhanced ladle refining furnace. The circuit breaker with a reactor is sequentially connected with a second resistor-capacitor absorption device, a reactor disconnector, a variable-ratio enhanced reactor, a variable-ratio enhanced transformer, and an enhanced ladle refining furnace. The variable-ratio enhanced transformer and the variable-ratio enhanced reactor are also connected with a voltage protection device.

[0010] The trolley voltage transformer is used to detect the voltage fluctuation on the grid side in real time.

[0011] The resistor-capacitor absorption device is an energy-saving variable non-linear resistor, which is used to absorb the switching overvoltage generated when the circuit breaker closes and opens.

[0012] The current transformer is arranged on the power supply incoming line side of 35kV, and detects the load change of the refining furnace in real time to provide current information for the system.

[0013] The variable-ratio enhanced reactor is configured with a reactor overvoltage protection, which is used to absorb the switching overvoltage generated when the variable-ratio enhanced reactor closes and opens.

[0014] The variable-ratio enhanced transformer is configured with a transformer overvoltage protection, which is used to absorb the switching overvoltage generated when the variable-ratio enhanced transformer closes and opens.

[0015] The closing and opening of the transformer circuit breaker and the circuit breaker with a reactor are interlocked with each other and cannot be closed simultaneously.

[0016] Compared with the prior art, the advantages of the technical solution of the utility model are as follows:

[0017] The power supply and distribution system of the self - adaptive enhanced ladle refining furnace of the present utility model can significantly reduce the power quality fluctuation and load impact of the ladle refining furnace through real - time dynamic detection and adjustment, and ensure the balance of the input power in the furnace. At the same time, the system has important guiding significance for improving the smelting power factor and shortening the smelting cycle of the ladle refining furnace, and plays a significant role in improving the stability and economic benefits of the iron and steel metallurgy system. Brief Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the power supply and distribution system of a self - adaptive enhanced ladle refining furnace described in the present utility model.

[0019] In the figure, 1 is the incoming line isolating handcart, 2 is the handcart voltage transformer, 3 is the breaker with transformer, 4 is the breaker with reactor, 5 is the resistor - capacitor absorption device, 6 is the current transformer, 7 is the isolating switch with reactor, 8 is the isolating switch with transformer, 9 is the variable - gear enhanced reactor, 10 is the variable - gear enhanced transformer, 11 is the over - voltage protection of the reactor, 12 is the over - voltage protection of the transformer, and 13 is the enhanced ladle refining furnace. Detailed Embodiment

[0020] The present utility model will be further described below in conjunction with the drawings and specific embodiments. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present utility model and are not used to limit the present utility model.

[0021] As Figure 1 shown, the present utility model discloses a power supply and distribution system of a self - adaptive enhanced ladle refining furnace, and the specific component descriptions are as follows.

[0022] Incoming line isolating handcart 1: As the entrance of the system, it connects the external 35 kV power supply to the 35 kV bus section of the high - voltage switchgear.

[0023] Handcart voltage transformer 2: Real - time detects the voltage fluctuation on the grid side and provides voltage information for the system.

[0024] Breaker with transformer 3 and breaker with reactor 4: Control the access of the transformer and the reactor respectively, and provide operating over - voltage protection.

[0025] Resistor - capacitor absorption device 5: Adopts an energy - saving variable non - linear resistor to absorb the operating over - voltage generated when the breaker closes and opens.

[0026] Isolating switch with reactor 7 and isolating switch with transformer 8: Control the working power supply of the variable - gear enhanced reactor and the transformer.

[0027] Variable - gear enhanced reactor 9 and variable - gear enhanced transformer 10: Provide variable power output to meet the heating requirements of the refining furnace.

[0028] Overvoltage protection 11 of the reactor and overvoltage protection 12 of the transformer: respectively absorb the switching overvoltages generated when the reactor and the transformer are switched on and off.

[0029] Current transformer 6: Real-time detects the load changes of the refining furnace and provides current information for the system.

[0030] The power supply and distribution system of the enhanced ladle refining furnace provided by the present utility model is a highly integrated and safe power supply solution. The power line system starts with a 35 kV power supply and is smoothly connected to the 35 kV busbar of the high-voltage switchgear through an incoming line isolating trolley, ensuring the stability and safety of the power supply connection. On the busbar, the trolley voltage transformer continuously monitors the voltage fluctuations on the grid side to ensure that the power supply quality is always maintained at a high standard.

[0031] To cope with possible overvoltage situations, the system is specifically equipped with a transformer circuit breaker and a reactor circuit breaker, which are closely connected to the resistor-capacitor absorption device. This device uses an energy-saving variable non-linear resistor to effectively absorb the generated switching overvoltages during the switching on and off operations of the circuit breaker, protecting the circuit from potential damage.

[0032] In addition, the system precisely controls the working power supplies of the variable-gear enhanced reactor and the variable-gear enhanced transformer through the reactor disconnecting switch and the transformer disconnecting switch. This design not only improves the flexibility of the power supply but also ensures that the system can be quickly and accurately adjusted according to actual needs.

[0033] At the same time, the variable-gear enhanced reactor and the transformer are also equipped with their respective overvoltage protection devices. These devices can quickly absorb the generated overvoltages during the switching on and off operations of the equipment, further enhancing the stability and safety of the system.

[0034] It is worth noting that the transformer circuit breaker and the reactor circuit breaker adopt an interlocking design. This interlocking mechanism ensures that these two circuit breakers are not simultaneously in the closed state, thus avoiding potential safety risks.

[0035] Finally, when the enhanced ladle refining furnace is in the smelting operation, the system real-time detects the load changes through the current transformer. This function enables the operator to monitor the working state of the refining furnace in real time and make corresponding adjustments according to the load changes to ensure the smooth progress of the smelting process.

[0036] Generally speaking, the power supply and distribution system of the present invention provides solid and reliable power support for the enhanced ladle refining furnace with its high degree of integration, stability and safety.

Claims

1. A power supply and distribution system for an adaptive enhanced ladle refining furnace, characterized in that: It includes a 35 kV power supply. The 35 kV power supply is connected to a 35 kV bus through an incoming line isolating handcart. The 35 kV bus is also respectively connected to a handcart voltage transformer, a transformer circuit breaker, and a circuit breaker with a reactor. The other end of the transformer circuit breaker is sequentially connected to a first resistor-capacitor absorption device, a transformer disconnector, a variable gear enhanced transformer, and an enhanced ladle refining furnace. The circuit breaker with a reactor is sequentially connected to a second resistor-capacitor absorption device, a reactor disconnector, a variable gear enhanced reactor, a variable gear enhanced transformer, and an enhanced ladle refining furnace. The variable gear enhanced transformer and the variable gear enhanced reactor are also connected to a voltage protection device.

2. The power supply and distribution system for an adaptive enhanced ladle refining furnace according to claim 1, characterized in that: The handcart voltage transformer is used to detect the voltage fluctuation on the grid side in real time.

3. The power supply and distribution system for an adaptive enhanced ladle refining furnace according to claim 2, characterized in that: The resistor-capacitor absorption device is an energy-saving variable non-linear resistor, which is used to absorb the switching overvoltage generated when the circuit breaker closes and opens.

4. The power supply and distribution system for an adaptive enhanced ladle refining furnace according to claim 3, characterized in that: A current transformer is arranged on the power supply incoming line side of the 35 kV power supply to detect the load change of the refining furnace in real time and provide current information for the system.

5. The power supply and distribution system for an adaptive enhanced ladle refining furnace according to claim 4, characterized in that: The variable gear enhanced reactor is configured with a reactor overvoltage protection, which is used to absorb the switching overvoltage generated when the variable gear enhanced reactor closes and opens.

6. The power supply and distribution system for an adaptive enhanced ladle refining furnace according to claim 5, characterized in that: The variable gear enhanced transformer is configured with a transformer overvoltage protection, which is used to absorb the switching overvoltage generated when the variable gear enhanced transformer closes and opens.

7. The power supply and distribution system for an adaptive enhanced ladle refining furnace according to claim 6, characterized in that: The resistor-capacitor absorption device is connected to a circuit breaker with a transformer and a circuit breaker with a reactor. The closing and opening of the circuit breaker with a transformer and the circuit breaker with a reactor are interlocked with each other and cannot be closed simultaneously.

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