On-line monitoring system for cell bottom temperature of aluminum electrolysis cell

Abstract

The utility model discloses an aluminum electrolysis cell bottom temperature on-line monitoring system which comprises a sensor unit, a signal relay module and a central control unit, the sensor unit is a non-contact infrared temperature measurement sensor and is fixedly arranged on the outer side of the bottom of the aluminum electrolysis cell through an assembly bracket; the sensor unit is externally connected with a temperature difference power generation device, the temperature difference power generation device comprises a temperature difference power generation sheet, and two ends of the temperature difference power generation sheet are attached to the aluminum electrolysis cell and far away from the aluminum electrolysis cell respectively so as to supply power to the sensor unit through the temperature difference between the aluminum electrolysis cell and the environment temperature; the signal relay module serves as a relay and is in communication connection with the sensor unit and the central control unit so as to wirelessly transmit the corresponding temperature data to the central control unit after receiving the temperature data collected by the sensor unit. According to the utility model, the temperature difference is utilized to generate power, and the generated electric energy is supplied to the non-contact sensor unit, thereby improving the working stability of the temperature measurement system and reducing the operation and maintenance cost.

Description

Technical Field

[0001] The utility model relates to the technical field of aluminum electrolysis, in particular to an online monitoring system for the bottom temperature of an aluminum electrolysis cell. Background Art

[0002] Aluminum electrolysis is a process for producing high-purity aluminum through the electrolysis of alumina. Using bauxite as raw material, this process first extracts alumina via the Bayer process, then electrolyzes it in electrolytic cells to produce aluminum metal. It is the primary production method in the modern aluminum industry. The bottom of the electrolytic cell typically consists of a refractory lining and a steel shell. During the electrolytic production process, the internal temperature of the cell is high. If the carbon material at the bottom of the cell is damaged, the refractory lining becomes uneven, potentially causing molten aluminum or electrolyte to flow down to the bottom, burning through the shell and leaking the furnace, potentially causing production accidents. Therefore, during production, the temperature of the electrolytic cell bottom must be monitored and cooling measures implemented as appropriate.

[0003] Currently, the monitoring technologies for the bottom temperature of electrolytic cells mainly include manual inspection, robot inspection and online monitoring.

[0004] Manual inspection methods are time-consuming and pose safety risks, and data records are incomplete and cannot accurately reflect the bottom condition of the tank in real time;

[0005] Although robot inspection reduces safety risks, its installation and debugging process is complicated, its operational stability is poor, and its service life is limited;

[0006] Online monitoring systems can overcome the shortcomings of the first two methods, but existing online monitoring technologies rely on a large number of contact temperature sensors for measurement. Under this measurement method, the wired connection between the sensor and the signal transmitter makes the wiring at the bottom of the tank complicated, increasing safety risks. At the same time, contact temperature sensors not only have poor measurement stability in special environments such as strong magnetic fields, high temperatures, and high dust, but are also prone to sensor detachment, resulting in measurement failure. In addition, contact sensors require independent battery power units, and these batteries need to be replaced regularly. Replacing batteries in the narrow space at the bottom of the tank is not only labor-intensive but also poses safety risks. In addition, if the battery is installed close to a high-temperature area, there is a risk of explosion. Utility Model Content

[0007] The technical problem solved by the present invention is to provide an online monitoring system for the bottom temperature of an aluminum electrolytic cell, which can effectively overcome the shortcomings of the existing technology, improve the accuracy and safety of electrolytic cell temperature monitoring, and solve the defects in the above technical background.

[0008] The technical problem solved by the present invention is achieved by the following technical solutions:

[0009] An online monitoring system for the bottom temperature of an aluminum electrolysis cell comprises a sensor unit, a signal relay module and a central control unit;

[0010] The sensor unit is a non-contact infrared temperature sensor, and there are multiple sensors fixed to the outside of the bottom of the aluminum electrolysis cell by an assembly bracket, with the temperature measuring head of the sensor unit facing the area to be measured at the bottom of the aluminum electrolysis cell; the sensor unit is externally connected to a thermoelectric power generation device, and the thermoelectric power generation device includes a thermoelectric power generation sheet, and the two ends of the thermoelectric power generation sheet are respectively close to the aluminum electrolysis cell and away from the aluminum electrolysis cell, so that the sensor unit is powered by the temperature difference between the aluminum electrolysis cell and the ambient temperature;

[0011] The signal relay module is connected to the sensor unit and the central control unit as a relay to wirelessly transmit the corresponding temperature data to the central control unit after receiving the temperature data collected by the sensor unit.

[0012] As a further limitation, the sensing element of the sensor unit is encapsulated in a dustproof box; the dustproof box is a closed box formed of a high-temperature resistant and corrosion-resistant metal material, the dustproof box has a threading hole and an open surface, the sensing element of the sensor unit is encapsulated and fixed with encapsulation glue after being installed in the dustproof box, and the temperature measuring head of the sensor element in the encapsulated state is arranged outward at the open surface position;

[0013] The dustproof box has a heat dissipation pipe installed inside the box body and is provided with an anti-magnetic structure; the anti-magnetic structure is a high-magnetic permeability shell or an anti-magnetic coating or a combination of the two;

[0014] The dustproof box is assembled on the outside of the temperature measurement area at the bottom of the aluminum electrolytic cell through a detachable bracket, and a gap of 20 to 50 cm is maintained between the dustproof box and the bottom of the cell.

[0015] As a further limitation, the signal relay module is a relay router.

[0016] As a further limitation, the signal relay module and the end of the thermoelectric power generation sheet away from the aluminum electrolysis cell are arranged in a dustproof box structure.

[0017] As a further limitation, the signal relay module further includes an encoding module. After the sensor unit is matched and connected to the signal relay module, the encoding module is used to encode the position information of the sensor unit to achieve rapid positioning of the temperature anomaly.

[0018] As a further limitation, the signal relay module communicates with the sensor unit via Lora data wireless transmission technology, and transmits data to the central control unit via WiFi wireless transmission technology or Lora data wireless transmission technology.

[0019] As a further limitation, the central control unit is an industrial computer or an embedded industrial tablet computer having a storage module and a computing module;

[0020] The central processing unit has an alarm device, which is an audible and visual alarm device, and is used to send an alarm signal when the temperature exceeds a preset range.

[0021] The central control unit also has a remote communication module. After obtaining authorization, the remote device can access the remote communication module through the network to realize data reading and exchange with the central control unit.

[0022] Beneficial effect: The utility model provides an online temperature monitoring system for the bottom of an aluminum electrolytic cell, which can effectively adapt to the strong magnetic field, high temperature and high dust environment of the bottom of the aluminum electrolytic cell under the conditions of the aluminum electrolysis process. It measures the temperature of the bottom of the aluminum electrolytic cell by setting a non-contact infrared temperature sensor in a passive (no external power supply and battery power supply are required, and the working power is directly obtained by using energy conversion technology) and wireless (Lora is used to realize wireless data communication). It perfectly solves the problems of sensor working power supply and safety risks caused by wiring at the bottom of the cell in a high-temperature environment, so that the temperature measurement at the bottom of the cell has the characteristics of passive, wireless and high precision, and is not affected by strong magnetic fields and high-temperature dust environments. It solves the problems of traditional patch sensors that are easy to fall off, have low reliability and short service life, and can effectively meet the temperature monitoring requirements of the bottom of the electrolytic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of a preferred embodiment of the present utility model.

[0024] Among them: 1. Aluminum electrolytic cell; 2. First sensor unit; 3. Second sensor unit; 4. Third sensor unit; 5. Fourth sensor unit; 6. First signal relay module; 7. Second signal relay module; 8. Central control unit; 9. Temperature difference power generation device; 10. A-end of temperature difference power generation sheet; 11. B-end of temperature difference power generation sheet; 12. Dustproof box; 13. Packaging glue; 14. Sensor element. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0026] See also Figure 1 The preferred embodiment of the online monitoring system for the bottom temperature of an aluminum electrolytic cell is shown. In this embodiment, the online monitoring system for the bottom temperature of an aluminum electrolytic cell is provided with four sensor units (i.e. corresponding to Figure 1The first sensor unit 2, the second sensor unit 3, the third sensor unit 4 and the fourth sensor unit 5) are used to perform online real-time dynamic monitoring of the bottom temperature of a small-sized aluminum electrolysis cell 1. When the bottom temperature of the aluminum electrolysis cell at the measurement position of the corresponding sensor unit is abnormal, the fault location and fault code are fed back to the upper central control unit 8 through the first signal relay module 6 / the second signal relay module 7 with corresponding communication connection to ensure the safe, reliable and stable operation of the aluminum electrolysis cell 1.

[0027] In other embodiments, considering that the size of the aluminum electrolysis cell 1 may be larger, more sensor units may be required to ensure uniform monitoring of the temperature across the entire cell bottom. For example, for a large aluminum electrolysis cell, eight or more sensor units may be required, evenly distributed around the cell bottom, to achieve more precise temperature control. However, the structural style and arrangement of these sensor units are similar to those of this embodiment, and the same structural analogy can be applied.

[0028] In this embodiment, the four sensor units have the same structure. The structure is described by taking the first sensor unit 2 as an example. The first sensor unit 2 includes a sensor element 14 as a working element. The sensor element 14 is encapsulated in a dustproof box 12 using a highly thermally conductive weather-resistant encapsulation glue. The corresponding dustproof box 12 is a closed box body formed of a high-temperature resistant and corrosion-resistant metal material. The front of the closed box body has a window and a threading hole is formed on the bottom. The temperature measuring head of the sensor element 14 is located at the window position to ensure that the temperature of the bottom of the aluminum electrolysis cell 1 can be accurately measured.

[0029] The sensor unit in this embodiment is a non-contact infrared temperature sensor, that is, the sensing element 14 is a non-contact infrared temperature sensor. The infrared temperature measurement accuracy is high and is not affected by strong magnetic fields. The temperature measurement range of the infrared measurement sensor covers a wide range of 50°C to 500°C. By isolating it from the aluminum electrolysis cell 1 at a safe measurement distance, it can fully meet the temperature measurement requirements of complex industrial environments.

[0030] In addition, the non-contact infrared temperature measurement method is adopted, and the temperature sensor is easy to install and disassemble, which is conducive to the transfer, installation and use of the monitoring system. A set of monitoring systems can be used for temperature monitoring of multiple electrolytic cells in a time-sharing manner.

[0031] In this embodiment, the dust box 12 is formed of a highly diamagnetic metal material with excellent diamagnetic properties. The inner wall of the dust box 12 is also coated with diamagnetic paint. This diamagnetic structure of the dust box 12 ensures that the sensor unit can still operate stably in strong magnetic fields. In other embodiments, considering the operating environment of the sensor unit, a heat dissipation pipe can be provided within the dust box 12, adjacent to the inner wall, to help maintain the stable operation of the sensor element 14 in high-temperature environments.

[0032] The first sensor unit 2 with a dustproof box 12 is assembled on the outside of the temperature measurement area at the bottom of the aluminum electrolytic cell through a detachable bracket during setting, and a gap of 20 to 50 cm is maintained between the sensor unit and the bottom of the cell. This ensures that the sensor unit is away from the high-temperature area while maintaining an appropriate distance from the bottom of the cell to ensure measurement accuracy and numerical stability.

[0033] In this embodiment, the first sensor unit 2, the second sensor unit 3, the third sensor unit 4 and the fourth sensor unit 5 are connected to the wire holes of the dustproof box 12 and powered by the thermoelectric power generation device 9. The main structure of the thermoelectric power generation device 9 is a thermoelectric power generation chip, which is an energy conversion semiconductor chip that generates electricity based on the principle of thermoelectric effect. The thermoelectric power generation chip has two pin ends, namely, Figure 1 The thermoelectric power generation sheet A end 10 and the thermoelectric power generation sheet B end 11 are shown.

[0034] Thermoelectric power generation device 9 utilizes the temperature gradient generated by the temperature difference between thermoelectric power generation plate A end 10 and thermoelectric power generation plate B end 11 to perform energy conversion. In this embodiment, thermoelectric power generation device 9 utilizes the temperature gradient generated by the heat dissipation of the cradle at the bottom of the electrolytic cell. Thermoelectric power generation plate A end 10 is abutted against the cradle side of the aluminum electrolytic cell 1, while thermoelectric power generation plate B end 11 is located on the low-temperature side away from the cradle. This allows the internal carrier migration of the thermoelectric material in the energy conversion semiconductor sheet, generating a voltage difference and achieving energy conversion. The thermoelectric power generation device 9 that completes energy conversion is connected to the sensor element 14 via a wire, providing the sensor element 14 with the electrical energy required for operation. Actual field operation has shown that the temperature gradient at the bottom of the aluminum electrolytic cell 1 is large, fully meeting the temperature difference required for energy extraction.

[0035] In this embodiment, as far as the sensor unit is concerned, if it is not powered by a battery, but the sensor is powered locally, an appropriate installation position is selected, and the sensor thermodynamic structure is optimized, it is entirely possible to achieve reliable operation of the sensor in a high temperature and high dust environment; and by optimizing the distribution of measuring points and the installation position of the sensor, the position of the sensor unit can be reasonably set based on the analysis of the temperature distribution characteristics of the bottom of different types of aluminum electrolytic cells, so as to achieve full coverage and high-precision monitoring of the bottom temperature.

[0036] The first sensor unit 2 and the second sensor unit 3 among the four sensor units are communicatively connected to the first signal relay module 6, while the third sensor unit 4 and the fourth sensor unit 5 are communicatively connected to the second signal relay module 7. The first signal relay module 6 and the second signal relay module 7 also communicate with the upper central control unit 8 at the same time.

[0037] In this embodiment, both the first signal relay module 6 and the second signal relay module 7 utilize relay routers. Given the importance of communication quality, the first and second signal relay modules 6 and 7 should be located a short distance from the sensor units they communicate with. However, due to the complex environment surrounding the electrolytic cell, to ensure a stable operating environment for the first and second signal relay modules 6 and 7, if conditions and costs permit, these two relay modules can be installed within a dustproof box structure along with the B-end 11 of the thermoelectric generator chip to provide the necessary protection.

[0038] In addition, the first signal relay module 6 and the second signal relay module 7 also include a coding module, which is used to encode the signal transmitted by the sensor unit. The effect of this coding processing is to improve the accuracy and anti-interference ability of signal transmission. At the same time, the position information of the sensor unit can also be encoded through the coding processing, so that the position of the temperature anomaly can be quickly located through the position information of the sensor unit after being read by the central control unit 8.

[0039] In this embodiment, LoRa wireless transmission technology is used for communication between the sensor unit and the corresponding signal relay module, as well as between the signal relay module and the central control unit. LoRa is a wireless network based on 1GHz technology, characterized by long transmission distance, suitable for large-scale data acquisition. It has the characteristics of long transmission distance and strong anti-interference ability, and is suitable for stable operation in the high temperature and strong magnetic field environment of aluminum electrolysis cells. In addition, the low power consumption characteristics of LoRa technology extend the battery life of the sensor unit. LoRa's spread spectrum modulation technology uses linear spread spectrum modulation, which not only prevents mutual interference even when terminals transmit information simultaneously at the same frequency, but also significantly increases the communication distance. With a reasonable number of relay routers, data from multiple nodes can be received and processed in parallel, which can effectively expand the capacity of the network.

[0040] When the corresponding sensor unit detects that the temperature at the corresponding position of the tank bottom is abnormal, the first signal relay module 6 and the second signal relay module 7 will send the fault information to the central control unit 8 in a wireless manner.

[0041] In this embodiment, central control unit 8 is an industrial computer with a built-in data processing module responsible for receiving temperature data from the sensor units and performing real-time analysis and processing. Central control unit 8 is capable of analyzing and processing the sensor unit temperature data received via first signal relay module 6 and second signal relay module 7, determining whether an abnormality exists, and triggering a corresponding alarm mechanism based on a preset threshold. This alarm mechanism is based on an alarm device, which in this embodiment is an audible and visual alarm device, which is used to issue an alarm signal when the temperature exceeds a preset range.

[0042] In addition, the central control unit 8 of this embodiment is also equipped with a storage module for storing historical data and performing trend analysis. The results of this trend analysis can be used to guide the maintenance and operation optimization of the aluminum electrolytic cell. By analyzing historical temperature data, the trends and patterns of cell bottom temperature changes can be discovered, providing a scientific basis for adjusting the maintenance cycle of the electrolytic cell and the electrolysis process parameters. For example, if the temperature in a certain area is found to be too high for a long time, it may indicate that the electrolysis reaction in that area is too intense, and the current distribution of the electrolytic cell or the operating status of the cooling system need to be adjusted.

[0043] To enable remote monitoring and data exchange, the central control unit 8 of this embodiment also includes a remote communication module. Authorized remote devices can access the remote communication module via the network, enabling remote reading and exchange of aluminum electrolysis cell bottom temperature data. This not only increases the flexibility of the monitoring system but also facilitates production management.

[0044] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. An online monitoring system for the bottom temperature of an aluminum electrolysis cell, characterized in that: It includes a sensor unit, a signal relay module and a central control unit; The sensor unit is a non-contact infrared temperature sensor, and there are multiple sensors fixed to the outside of the bottom of the aluminum electrolysis cell by an assembly bracket, with the temperature measuring head of the sensor unit facing the area to be measured at the bottom of the aluminum electrolysis cell; the sensor unit is externally connected to a thermoelectric power generation device, and the thermoelectric power generation device includes a thermoelectric power generation sheet, and the two ends of the thermoelectric power generation sheet are respectively close to the aluminum electrolysis cell and away from the aluminum electrolysis cell, so that the sensor unit is powered by the temperature difference between the aluminum electrolysis cell and the ambient temperature; The signal relay module is connected to the sensor unit and the central control unit as a relay to wirelessly transmit the corresponding temperature data to the central control unit after receiving the temperature data collected by the sensor unit.

2. The online monitoring system for bottom temperature of an aluminum electrolysis cell according to claim 1, characterized in that: The sensing element of the sensor unit is encapsulated in a dustproof box; The dustproof box is a high-temperature-resistant and corrosion-resistant metal closed box body; the dustproof box has a threading hole and an open surface. After the sensing element of the sensor unit is installed in the dustproof box, it is encapsulated and fixed with packaging glue. The temperature measuring head of the sensing element in the encapsulated state is set outward at the open surface position.

3. The online monitoring system for bottom temperature of an aluminum electrolysis cell according to claim 2, characterized in that: A heat dissipation pipe is laid inside the box body of the dustproof box, and an anti-magnetic structure is provided; the anti-magnetic structure is a high-magnetic permeability shell or an anti-magnetic coating or a combination of the two.

4. The online monitoring system for bottom temperature of an aluminum electrolysis cell according to claim 2, characterized in that: The dustproof box is assembled on the outside of the temperature measurement area at the bottom of the aluminum electrolytic cell through a detachable bracket, and a gap of 20 to 50 cm is maintained between the dustproof box and the bottom of the cell.

5. The online monitoring system for bottom temperature of aluminum electrolysis cell according to claim 1, characterized in that: The signal relay module is a relay router.

6. The online monitoring system for bottom temperature of an aluminum electrolysis cell according to claim 1, characterized in that: The signal relay module and the end of the thermoelectric power generation sheet away from the aluminum electrolysis cell are arranged in the dustproof box structure.

7. The online monitoring system for bottom temperature of an aluminum electrolysis cell according to claim 1, characterized in that: The signal relay module further includes an encoding module. After the sensor unit is matched and connected to the signal relay module, the encoding module is used to encode the position information of the sensor unit to achieve rapid positioning of the temperature anomaly position.

8. The online monitoring system for bottom temperature of aluminum electrolysis cell according to claim 1, characterized in that: The signal relay module communicates with the sensor unit via Lora data wireless transmission technology, and performs wireless data transmission with the central control unit via WiFi or Lora.

9. The online monitoring system for bottom temperature of an aluminum electrolysis cell according to claim 1, characterized in that: The central control unit is an industrial computer or an embedded industrial tablet computer having a storage module and a computing module.

10. The online monitoring system for bottom temperature of an aluminum electrolysis cell according to claim 9, characterized in that: The central control unit also has a remote communication module. After obtaining authorization, the remote device can access the remote communication module through the network to realize data reading and exchange with the central control unit.

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