Electrical protection device for cement production

Abstract

The invention discloses an electrical protection device for cement production, which comprises a microprocessor unit, a sensor unit and a display panel, and is characterized in that the sensor unit comprises a voltage sensor and a current sensor and is used for acquiring current and / or voltage signals of one or more of a crusher, a ball mill, a high-voltage power distribution cabinet, a transformer or a motor; the digital signal is sent to the microprocessor unit; the microprocessor unit receives the digital signal and judges whether abnormity occurs according to a preset threshold value, and if abnormity occurs, the microprocessor unit sends a corresponding control instruction to the relay, so that the relay cuts off a power supply or takes other protection measures; meanwhile, the microprocessor unit displays the alarm information through the display panel and records the data, so that subsequent analysis and maintenance are facilitated. According to the invention, key parameters such as current, voltage and the like can be effectively monitored, and timely measures can be taken when abnormity occurs, so that important electrical equipment and circuits in cement production can be protected.

Description

Technical Field

[0001] The invention belongs to the technical field of cement production, and in particular relates to an electrical protection device used in cement production. Background Art

[0002] Cement production is a complex process involving multiple steps and multiple types of production equipment. Electrical control is present in the raw material preparation stage, calcination stage, grinding stage, storage and transportation stage. Common types of electrical faults in cement plants today include short circuits, overloads, poor grounding, etc., which have a significant impact on production efficiency and safety. A short circuit refers to the direct connection between two points in a circuit, resulting in a sharp increase in current. In a cement plant, this may occur on key equipment such as high-voltage distribution cabinets, transformers or motors. Overload conditions occur when electrical equipment is subjected to a workload that exceeds the rated value for a long period of time. For example, if large mechanical equipment such as crushers and ball mills are overloaded, the temperature of their internal coils will rise. Failure of the grounding system or poor connection can make the equipment casing live, especially in humid environments. Summary of the invention

[0003] In view of the above-mentioned defects, the present invention provides an electrical protection device for cement production, which can effectively monitor key parameters such as current and voltage, and take timely measures when abnormalities occur, so as to protect important electrical equipment and circuits in cement production.

[0004] An electrical protection device for cement production includes a microprocessor unit, a sensor unit and a display panel, wherein the sensor unit includes a voltage sensor and a current sensor, collects current and / or voltage signals from one or more of a crusher, a ball mill, a high-voltage distribution cabinet, a transformer or a motor, and converts the current and / or voltage signals into digital signals and sends them to the microprocessor unit; the microprocessor unit receives the digital signals and determines whether an abnormality occurs based on a preset threshold value. If an abnormality occurs, the microprocessor unit will issue a corresponding control instruction to a relay to cut off power or take other protective measures; at the same time, the microprocessor unit displays alarm information through the display panel and records the data for subsequent analysis and maintenance.

[0005] Preferably, the microprocessor unit is a Siemens S7-200SMART PLC.

[0006] Preferably, the signal output terminals of the voltage sensor and the current sensor are connected to the DI8 interface of the PLC, and the GND or COM terminal is connected to the common terminal of the PLC.

[0007] Preferably, the electrical protection device also includes a temperature sensor, which collects one or more temperature signals in the preheater, the rotary kiln, the kiln tail, and before and after the heat exchanger; the signal output end of the temperature sensor is respectively connected to the PLC analog input channel +IN, -IN interface, and the shielded line is grounded to reduce interference.

[0008] Preferably, the electrical protection device is also equipped with a security authentication mechanism. The authentication method is password-based identity authentication. The access control strategy is to define different levels of permissions, assign corresponding access rights according to user responsibilities, and follow the principle of least privilege. Communication is encrypted communication using the SSL / TLS protocol, and local storage data is encrypted and saved.

[0009] Preferably, the relay is connected to one or more of the crusher, the ball mill, the high-voltage distribution cabinet, and the transformer, and connects or disconnects the circuit according to the control signal.

[0010] Preferably, when the crusher is connected to the crusher, the main power line of the crusher is connected through the normally closed contact NC or normally open contact NO of the relay, and a low voltage signal is output from the PLC to the relay coil to trigger the relay to operate; when the coil is energized, the contacts switch states, thereby allowing / preventing current from flowing through the crusher motor.

[0011] Preferably, when the ball mill is connected to the relay and uses a three-phase AC motor, three single-pole relays are used to control each phase of the power supply respectively, or a three-pole relay is used to control all phases simultaneously; an interlocking mechanism is set so that the ball mill is allowed to start only when the set conditions are met.

[0012] Preferably, when the high-voltage distribution cabinet is connected to the relay, an isolating switch and / or a grounding protection device is additionally installed, and auxiliary contacts are used to provide status feedback to the control system.

[0013] Preferably, when the transformer is connected to the relay, a small relay is connected to the secondary side of the transformer to control the downstream load; when there are multiple independent loads powered by the same transformer, multiple relays are used to achieve separate control of each branch.

[0014] The beneficial effects of the present invention are: The invention can provide real-time monitoring functions, monitor key parameters such as current and voltage; automatically detect and quickly respond to abnormal situations to prevent accidents from happening or expanding; have alarm prompts, data recording and other functions, which are convenient for later analysis and maintenance, and are suitable for important electrical components such as motors, transformers, switch cabinets in various cement production equipment. It can reduce unplanned downtime caused by electrical failures, extend the service life of equipment, save maintenance costs, improve the safety of the working environment, and protect the lives and property of employees. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below.

[0016] Figure 1 It is a module diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The embodiments of the present invention provide a method for making the purpose, technical solution and advantages of the present invention more clear, and the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] The present invention provides an electrical protection device for cement production, which can effectively monitor key parameters such as current and voltage through the coordinated action of components such as a sensor unit, a microprocessor unit, a relay / contactor and a display panel, and take timely measures when an abnormality occurs, thereby protecting important electrical equipment and circuits in cement production and ensuring the stable operation of the cement production line and safe and efficient production.

[0019] like Figure 1 As shown, an electrical protection device for cement production provided by an embodiment of the present invention includes: a sensor unit, a microprocessor unit, a relay and a display panel connected to a circuit; the sensor unit is responsible for collecting electrical signals, such as current, voltage, etc., and converting them into digital signals and sending them to the microprocessor unit; the microprocessor unit receives the digital signal and determines whether an abnormality occurs based on a preset threshold; if an abnormality occurs, the microprocessor unit will issue a corresponding control instruction to the relay / contactor to cut off the power supply or take other protective measures; at the same time, the microprocessor unit will also display an alarm message through the display panel to inform the user what has happened; in addition, the microprocessor unit will also record the data for subsequent analysis and maintenance.

[0020] In this application, the microprocessor unit is the core component, and its model is Siemens S7-200SMART PLC. This PLC has high-speed and stable performance, and has rich peripherals and communication interfaces, which is suitable for industrial-level applications. It also has an event recording function, which can record module fault information and system operation data, which is convenient for troubleshooting and data analysis.

[0021] Specifically, it has the following features: (1) High performance: Using a high-performance single-chip microcomputer as the controller, it can achieve high-precision and fast data acquisition and control. (2) Intelligence: With perfect hardware and software design, it can realize complex control and analysis functions. (3) Scalability: Supports a variety of communication protocols and interfaces, which is convenient for interconnection with host computers, industrial computers, etc. (4) High reliability: It has multiple I / O ports to choose from, and the input / output channels have isolation and protection functions, which can improve the system's anti-interference ability and stability.

[0022] The sensor unit includes a current transformer and a voltage transformer, which are responsible for measuring the AC current and AC voltage respectively, and converting the data into digital signals and transmitting them to the microprocessor unit.

[0023] In this embodiment, the sensor unit also includes a temperature sensor. In the cement production industry, the temperature sensor is mainly used to monitor and control the temperature of each process stage. In the early stage of cement production, raw materials such as limestone and clay need to be preheated in a preheater. The temperature sensor installed in the preheater can monitor the material temperature in real time to ensure the best preheating effect, thereby improving the efficiency of the subsequent calcination process. The rotary kiln is one of the core equipment for cement manufacturing, which is used to heat the pretreated materials to a high temperature to complete the sintering process of the clinker. The temperature sensors set at different positions in the kiln can accurately measure the operating temperature distribution inside the kiln body, help operators adjust combustion parameters (such as fuel quantity, air supply), maintain stable kiln conditions, and prevent overheating or local cooling problems. The high-temperature clinker discharged from the kiln tail needs to be cooled quickly, usually by a grate cooler to achieve rapid cooling. In this process, the temperature sensors arranged in each section of the grate cooler are used to track the cooling progress of the clinker, ensure its uniform cooling, and avoid product quality problems caused by excessive temperature differences. From the perspective of energy conservation and environmental protection, exhaust gas emission monitoring is realized based on temperature sensors: the exhaust gas temperature generated by the kiln needs to be strictly monitored. Temperature sensors installed on chimneys or exhaust pipes can provide accurate data support so that appropriate measures can be taken to reduce pollutant emissions, such as optimizing the performance of the denitrification system; waste heat recovery is realized based on temperature sensors: the steam and hot water temperatures before and after entering the heat exchanger are detected to ensure the efficient operation of the energy conversion system, etc.

[0024] According to the sensor output signal type (such as digital or analog), select the corresponding PLC input module, that is, the current transformer and voltage transformer are connected to the DI8 interface of the PLC, and the temperature sensor is connected to the AI4 interface of the PLC. When connecting, confirm the working voltage requirements of the sensor (such as DC 24V) and provide a stable power supply for the sensor. For digital sensors (i.e. current and voltage sensors), a common terminal (COM) is usually required to complete the loop; for analog sensors, an additional reference voltage source may be required (such as a thermocouple temperature sensor using cold end compensation, a high-precision thermistor temperature sensor, etc.). In this embodiment, a general analog output sensor is used, and the sensor itself should already contain an internal reference voltage for generating this proportional output. In order to reduce noise interference and ensure long-term stability, an external precision reference voltage can also be introduced for comparison or calibration. When connecting, connect the positive pole (signal output terminal) of the digital sensor (i.e. current and voltage sensor) to the PLC input point, and the negative pole (usually GND or COM) to the common terminal of the PLC. Analog sensor (i.e. temperature sensor): According to the sensor manual, connect the output pins of the sensor to the corresponding terminals of the PLC analog input channel (such as +IN, -IN, etc.). At the same time, ensure that the shielded wire is grounded to reduce interference.

[0025] The relay connects or disconnects the circuit according to the control signal. In this embodiment, the relay is connected to one or more of the crusher, ball mill, high-voltage distribution cabinet, and transformer. When the crusher is connected to the relay, ensure that the selected relay can withstand the large current impact when the crusher is started, and its contact capacity is large enough to handle the working current during normal operation. A low voltage signal (such as 24V DC) is output from the PLC or other controller to the relay coil to trigger the relay action. When the coil is energized, the contacts switch states, thereby allowing / preventing current from flowing through the crusher motor. When the ball mill is connected to the relay, if the ball mill uses a three-phase AC motor, three single-pole relays can be used to control each phase of the power supply separately, or a three-pole relay can be used to control all phases at the same time. Set up an appropriate interlocking mechanism, for example, the ball mill is allowed to start only when certain conditions are met (such as the lubrication system is working properly). When the high-voltage distribution cabinet is connected to the relay, directly operating the high-voltage level line may involve more complex relay types, such as vacuum contactors or solid state relays (SSRs), so that the circuit can be reliably disconnected or closed at higher voltages. Due to the high voltage involved, effective isolation measures need to be taken, including but not limited to installing isolating switches, grounding protection devices, etc., to ensure the safety of personnel and equipment. Auxiliary contacts are used to provide status feedback to the control system so that the working condition of the distribution cabinet can be monitored in real time. When the transformer is connected to the relay, a small relay is connected to the secondary side of the transformer to control the downstream load (generally, the relay is not used directly to control the primary side (high voltage side) of the transformer, but more attention is paid to the control of the secondary side (low voltage side)). If there are multiple independent loads powered by the same transformer, multiple relays can be used to achieve separate control of each branch. Considering that a large inrush current will be generated when the transformer is first powered on, a relay with appropriate surge tolerance should be selected and used in combination with other protection elements such as fuses.

[0026] In addition, the electrical protection device for cement production is also equipped with a digital display and operation panel to display information such as operating status, parameters and historical records, and to facilitate user operation and settings.

[0027] In order to ensure the safety and reliability of the system, this electrical protection device also sets up a security authentication mechanism. Identity authority needs to be verified before the device is started. Only authorized users can operate it, and the authentication information will be automatically updated at regular intervals to enhance security. Password-based authentication is adopted, and two-factor or multi-factor authentication (2FA / MFA) can also be selected according to security requirements: combining passwords with one-time verification codes (OTP), hardware tokens or other biometric technologies (fingerprints, facial recognition, etc.) to enhance security, or smart cards / USB Keys: using physical media to store private keys, and only inserting the correct card can authenticate the identity, or certificate authentication: using public key infrastructure (PKI) to confirm the user's identity through digital certificates. Implement access control policies: define different levels of permissions, assign corresponding access rights according to the user's responsibilities, follow the principle of least privilege, and require multiple authorization processes for critical tasks, that is, multiple people with appropriate permissions must agree to perform specific actions.

[0028] In this embodiment, the following security authentication mechanism is constructed: User login: Each time the module is started or restarted, a user name and password are required; if 2FA is supported, an SMS verification code is additionally sent to a preset mobile phone number. Remote configuration: If remote parameter modification is allowed, the client identity must first be verified through a digital certificate under the PKI system, and then the instructions are transmitted through the HTTPS channel. Local maintenance interface: When connecting to a computer via a USB port, a specially issued USB Key must be inserted to unlock advanced options. Logging: The built-in non-volatile memory is used to store each successful login and important configuration change information, and is uploaded to the cloud server for backup. Firmware update: Only signed firmware packages from official channels are accepted, an integrity check is performed before updating, and the system automatically restarts to the new version after completion.

[0029] The system is also equipped with fault prediction and diagnosis functions. It uses artificial intelligence algorithms to conduct machine learning on historical data and build a data model. Then, by analyzing and comparing current data, it predicts possible faults. Once an abnormal situation is found, it can issue a warning in time and take corresponding measures.

[0030] Software configuration: Download and install STEP 7 Micro / WIN SMART programming software. After starting the programming software, create a new project file and select the correct PLC type according to the actual CPU model used. Add the selected input module in the "Hardware Configuration" tab and specify its address range. For each input point, you can assign a specific function or variable name for subsequent programming reference. Design the logic control algorithm in the ladder diagram editor according to application requirements.

[0031] For example, if you want to read the data of the temperature sensor, you can add an operation instruction to read the AI ​​register value in the program, and determine whether to trigger certain actions through comparison instructions. Download the written program to the PLC, and then start online monitoring of the operating status. Check whether the status changes of each input point are in line with expectations, and adjust the parameters until the best effect is achieved. PT100 temperature sensor, it will output a 0-10V voltage signal corresponding to different temperature values.

[0032] Hardware part: Connect the two signal wires of the sensor to the +IN and -IN terminals of the PLC AI module respectively, and ensure that the sensor is powered normally.

[0033] Software part: In STEP 7 Micro / WIN SMART, set the AI ​​channel to 0-10V input mode, and then use built-in functions (such as SCALE_X) to convert the raw AD value into the actual temperature value for processing.

[0034] Relay / contactor: Its action is controlled by DO (Digital Output) module.

[0035] Temperature sensor (analog input) When the temperature exceeds 80°C, the PLC activates the relay to cut off the power supply to the heating equipment. Give an example of ladder logic: I0.0 represents the first channel of the AI ​​module, which is used to read the value of the temperature sensor; Q0.0 represents the first output point of the DO module, which is used to control the relay. When the temperature reaches or exceeds 80°C, Q0.0 becomes a high level, causing the relay to cut off the power supply. Siemens S7-200SMART PLC automatically executes protection measures based on sensor feedback to improve the automation level and safety of the system. If there are more complex application requirements, such as multi-sensor linkage, remote monitoring and other functions, the program design can be further expanded and improved on the existing basis.

[0036] Working principle:

[0037] Under normal conditions: All parts work together to continuously monitor the health of the power system and maintain stable power supply.

[0038] When a fault occurs: When an abnormal fluctuation is detected, the protection action is immediately triggered, such as tripping and power failure, and an audible and visual alarm signal is issued, and the event details are uploaded to the central control system; a detailed fault log is recorded to provide a basis for subsequent investigation.

[0039] Recovery phase: Once the fault is eliminated, normal operation can be restored by manual reset or remote command.

[0040] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An electrical protection device for cement production, characterized in that: It includes a microprocessor unit, a sensor unit and a display panel. The sensor unit includes a voltage sensor and a current sensor, which collects current and / or voltage signals from one or more of a crusher, a ball mill, a high-voltage distribution cabinet, a transformer or a motor, and converts them into digital signals and sends them to the microprocessor unit; the microprocessor unit receives the digital signal and determines whether an abnormality occurs based on a preset threshold value. If an abnormality occurs, the microprocessor unit will issue a corresponding control instruction to the relay to cut off the power supply or take other protective measures; at the same time, the microprocessor unit displays the alarm information through the display panel and records the data for subsequent analysis and maintenance.

2. The electrical protection device for cement production according to claim 1, characterized in that: The microprocessor unit is Siemens S7-200SMART PLC.

3. The electrical protection device for cement production according to claim 2, characterized in that: The signal output terminals of the voltage sensor and the current sensor are connected to the DI8 interface of the PLC, and the GND or COM terminal is connected to the common terminal of the PLC.

4. The electrical protection device for cement production according to claim 1, characterized in that: The electrical protection device also includes a temperature sensor, which collects one or more temperature signals in the preheater, the rotary kiln, the kiln tail, and the front and back of the heat exchanger; the signal output end of the temperature sensor is respectively connected to the PLC analog input channel +IN, -IN interface, and the shielded line is grounded to reduce interference.

5. The electrical protection device for cement production according to claim 1, characterized in that: The electrical protection device is also equipped with a security authentication mechanism. The authentication method is password-based identity authentication. The access control strategy is to define different levels of permissions, allocate corresponding access rights according to the user's responsibilities, and follow the principle of least privilege. Communication is encrypted communication using the SSL / TLS protocol, and local storage data is encrypted and saved.

6. The electrical protection device for cement production according to claim 1, characterized in that: The relay is connected to one or more of the crusher, ball mill, high-voltage distribution cabinet, and transformer, and connects or disconnects the circuit according to the control signal.

7. The electrical protection device for cement production according to claim 6, characterized in that: When the crusher is connected to the crusher, the main power line of the crusher is passed through the normally closed contact NC or normally open contact NO of the relay, and a low-voltage signal is output from the PLC to the relay coil, triggering the relay to operate; when the coil is energized, the contacts switch states, thereby allowing / preventing current from flowing through the crusher motor.

8. The electrical protection device for cement production according to claim 6, characterized in that: When the ball mill is connected to the relay and the ball mill adopts a three-phase AC motor, three single-pole relays are used to control each phase of the power supply respectively, or a three-pole relay is used to control all phases at the same time; an interlocking mechanism is set so that the ball mill is allowed to start only when the set conditions are met.

9. The electrical protection device for cement production according to claim 6, characterized in that: When the high-voltage distribution cabinet is connected to the relay, an isolating switch and / or grounding protection device is additionally installed, and auxiliary contacts are used to provide status feedback to the control system.

10. The electrical protection device for cement production according to claim 6, characterized in that: When the transformer is connected to the relay, a small relay is connected to the secondary side of the transformer to control the downstream load; when there are multiple independent loads powered by the same transformer, multiple relays are used to achieve individual control of each branch.

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