Medium frequency furnace water circulation monitoring device

Abstract

The invention discloses a medium frequency furnace water circulation monitoring device, which belongs to a water circulation monitoring system, wherein the water circulation system comprises a main water inlet pipe, a main water outlet pipe, a branch water inlet pipe and a branch water outlet pipe, a row of branch water inlet pipes is arranged between each main water inlet pipe and the medium frequency furnace, a row of branch water outlet pipes is arranged between each main water outlet pipe and the medium frequency furnace, the two ends of the branch water inlet pipes are high and the middle is low, a flow meter, a thermometer and a pressure gauge are arranged in the middle of the branch water inlet pipes, an electromagnetic valve is arranged on the branch water inlet pipe, the flow meter, the thermometer, the pressure gauge and the electromagnetic valve are connected and communicated with a controller through a wired transmission cable, the flow meter, the thermometer and the pressure gauge are installed with a magnetic isolation shell, the wired transmission cable must be installed with an anti-magnetic pipe sleeve, the structure of the branch water outlet pipe is the same as that of the branch water inlet pipe, the controller receives the working frequency parameters of the medium frequency furnace control system, the controller is connected and communicated with the central control room, the central control room is provided with a host computer, all the monitoring data of the medium frequency furnaces in the factory are summarized, stored and analyzed, and the device is mainly used for monitoring the water circulation system of the medium frequency furnace.

Description

Technical Field

[0001] The invention relates to the technical field of steelmaking and ironmaking by using a medium frequency furnace, and in particular to a water circulation monitoring device for a medium frequency furnace. Background Art

[0002] The medium frequency furnace for steelmaking and ironmaking uses multiple (up to a dozen) circulating water pipes to cool down and protect the important parts of the furnace, usually including a dozen water inlet pipes and a dozen corresponding water outlet pipes. Whether the water circulation is normal or not reflects whether the furnace can work safely, so it is very important to monitor the pressure, temperature and flow of the water circulation pipes.

[0003] However, since the medium frequency furnace generates a high electromagnetic field, flow meters and other instruments cannot be installed close to the medium frequency furnace. The general practice now is to install flow meters, pressure gauges, and thermometers for the main water inlet and outlet pipes of each medium frequency furnace at a certain distance from the medium frequency furnace for monitoring. However, since the main water inlet pipe is divided into more than a dozen water inlet pipes, and more than a dozen water outlet pipes converge into the main water outlet pipe, even if the flow, pressure, and temperature of individual water inlet and outlet pipes are abnormal, the abnormality will not be reflected in the main pipe. Therefore, this method cannot achieve accurate monitoring and judgment.

[0004] In real life, people will specially arrange people to patrol the water circulation system, and judge only based on experience and sound. This not only wastes manpower but also has extremely poor judgment accuracy, and is completely unable to prevent danger from happening.

[0005] Patent application number: 202020349899.9 discloses a new medium frequency furnace water temperature alarm device, including a thermostat, a water temperature alarm control panel, a manifold, a medium frequency furnace return water shunt pipe, a drain pipe, a 24V DC power supply, an alarm and a three-way solenoid valve; the thermostat is fixed to the mounting support by fixing screws, the lower end of the water pipe joint is connected to the medium frequency furnace return water shunt pipe, a three-way solenoid valve is installed on the medium frequency furnace return water shunt pipe, and the output port of the three-way solenoid valve is connected to the drain pipe. The electric contact bimetallic strip in the thermostat of the present invention causes the self-recovering temperature switch contact to disconnect due to the deformation of the disc, and the alarm light on the water temperature alarm control panel lights up. The programmable single-chip microcomputer outputs a signal to input the alarm to issue a warning, and the three-way solenoid valve is input to open the sewage pipe outlet to discharge the slag. At the same time, the signal power supplied to the main PC board is actuated, the host is shut down and stops running, and the electronic components are effectively protected. However, the above patents have the following defects: all the devices do not solve the technical problem of magnetic field interference, and the measured quantity is inaccurate; when the water in the inlet and outlet pipes is in a half-pipe state, the data is even more inaccurate; the entire system cannot prevent the occurrence of danger in advance.

[0006] In summary, a new device and method is needed to monitor the pressure, flow rate, and temperature of each outlet and inlet pipe of the medium frequency furnace, and solve the problems of interference of strong magnetic fields on instruments, accurate measurement of instruments in the state of water flow in half pipes, and narrow installation space of medium frequency furnaces on site. Only in this way can the safe operation of medium frequency furnaces be monitored effectively and reliably. When an abnormality occurs locally in the medium frequency furnace, the local abnormality can be detected by monitoring the flow rate, pressure, and temperature of an inlet and outlet pipe, as well as the temperature difference, pressure difference, and flow difference between the inlet and outlet of a pipe, and the factory can be reminded to stop work for inspection. At the same time, through big data analysis, abnormal trends can be discovered in time to avoid accidents. Summary of the invention

[0007] In view of the lack or insufficiency of the existing technical means, the present invention provides a solution to monitor each water inlet and outlet pipe of the medium frequency furnace, and at the same time adopts U-shaped pipes, special pipe structures and anti-magnetic devices to ensure that the detection device works normally and accurately and can communicate normally.

[0008] In order to achieve the above object, the present invention provides a medium frequency furnace water circulation monitoring device, which is characterized by:

[0009] The water circulation monitoring device of the medium frequency furnace is provided with a water circulation system on the medium frequency furnace, wherein the water circulation system is used for cooling the key parts of the medium frequency furnace, and the water circulation system ensures the safe operation and operation of the medium frequency furnace, wherein the water circulation system includes a main water inlet pipe, a main water outlet pipe, a branch water inlet pipe and a branch water outlet pipe, and a row of branch water inlet pipes is provided between each main water inlet pipe and the medium frequency furnace, and a row of branch water outlet pipes is provided between each main water outlet pipe and the medium frequency furnace. Under normal circumstances, the number of branch water inlet pipes and branch water outlet pipes is greater than ten, and the number of branch water inlet pipes and branch water outlet pipes determines the cooling effect of the water circulation system, and the branch water inlet pipe and branch water outlet pipe have a high installation structure at both ends and a low installation structure in the middle, and the branch water inlet pipe is provided with a plurality of branch water outlet pipes. A metering device is provided at the lower end of the branch water pipe and the branch water pipe, and the metering device includes a flow meter, a thermometer and a pressure gauge. The branch water inlet pipe is provided with a solenoid valve, and the flow meter, thermometer, pressure gauge and solenoid valve are connected and communicated with the controller through a wired transmission cable. The flow meter, thermometer and pressure gauge are installed with a magnetic isolation shell, and the solenoid valve and the throttle valve are installed with a magnetic isolation shell. The wired transmission cable is equipped with an anti-magnetic pipe sleeve. The structure of the branch water pipe is the same as that of the branch water inlet pipe. The flow meter, thermometer and pressure gauge are all equipped with a communication module. The controller receives the flow, temperature and pressure of each branch water inlet pipe and branch water outlet pipe, and the controller is connected to and controls the solenoid valve.

[0010] The solenoid valve is used to control the opening and closing of the water flow. The flow meter, thermometer, pressure gauge and solenoid valve are connected to the controller for communication through a wired transmission cable. The flow meter, thermometer and pressure gauge are installed with a magnetic-proof shell. Due to the high magnetic field generated by the medium-frequency furnace, the electronic components will malfunction. After the magnetic-proof shell is installed, the electronic components are protected under the protection of the magnetic-proof shell. The wired transmission cable must be installed with an anti-magnetic pipe sleeve. The structure of the branch water pipe is the same as that of the branch water inlet pipe. The flow meter, thermometer and pressure gauge are all equipped with a communication module. The controller receives the flow, temperature and pressure of each branch water inlet pipe and branch water outlet pipe.

[0011] Preferably, in order to improve the measurement accuracy, it is better when the flow meter adopts a vortex flow meter.

[0012] Preferably: in order to improve the stability of the system, the flow meter, the thermometer and the pressure meter can be replaced by an integrated flow meter, which outputs three parameters: temperature, pressure and flow.

[0013] Preferably: to adapt to the narrow environment on site, the branch water inlet pipe and the branch water outlet pipe are U-shaped structures, the U-shaped pipe can be set in an inclined manner, the detection instrument can be installed horizontally or vertically, or in a structure with high ends and a low middle. The metering device is installed in the low middle area, and the low middle area must be horizontal and have a certain length to ensure accurate measurement of the flow meter.

[0014] Preferably: the water pipe of the water inlet pipe is a straight pipe I connected to an arc-shaped water pipe I, the arc-shaped water pipe I is connected to a straight pipe II, the right side of the straight pipe II is the tangent direction of the end of the arc-shaped water pipe I, the left side of the straight pipe II is a curved pipe II, the curved pipe II is connected to a straight pipe III, the straight pipe II and the straight pipe III are both installed in the tangent direction of the end point of the curved pipe II, and the metering device is installed on the straight pipe II.

[0015] Preferably: in order to better control the device, the controller includes a PLC board and a display screen, the PLC board is connected to the display screen, the flow meter, thermometer, pressure gauge and solenoid valve are connected to the PLC board through a wired transmission cable, and the PLC board is connected to the central control room. The field controller receives the flow, temperature and pressure of each branch water inlet pipe and branch water outlet pipe, and calculates the flow difference, temperature difference and pressure difference of each water inlet pipe and the corresponding water outlet pipe. If these detection values ​​and differences exceed a certain range, an alarm is issued. The field controller controls the solenoid valve as needed to control the water flow. The field controller communicates with the central control room. When an emergency occurs, it can communicate with the central control room to shut down the medium frequency furnace to avoid danger.

[0016] Preferably, before installing the flowmeters of the branch water inlet pipes and their corresponding branch water outlet pipes, two flowmeters with the closest errors are selected, which can effectively improve the measurement accuracy of the inlet and outlet flow difference of each branch water pipe.

[0017] The present invention has the following effects:

[0018] The present invention can effectively and reliably monitor the safe operation of the medium frequency furnace. When an abnormality occurs locally in the medium frequency furnace, the local abnormality can be found by monitoring the flow, pressure, temperature, and corresponding pressure difference of a water inlet and outlet pipe, and the factory can be reminded to stop work for inspection. At the same time, the present invention can solve the problem of accurate measurement of instruments in a half-pipe state and under strong electromagnetic interference. In addition, since a large amount of real-time and accurate data is obtained, abnormal trends can also be discovered in time through big data analysis to avoid accidents. The occurrence of danger is prevented, and accidents are truly prevented. Due to the use of this device, manpower can be saved. Usually, a steel plant has more than a dozen or even hundreds of medium frequency furnaces. Assuming a 4-shift arrangement, 2 workers per shift go to the site for inspection, and each worker is paid 8,000 yuan, which can save about 768,000 yuan of workers' wages each year. Due to the device, the occurrence of accidents is reduced, thereby indirectly improving the working efficiency of the medium frequency furnace, thereby increasing product profits by more than 10 million yuan each year. In summary, each set of devices can bring more than 10.768 million profit margins to the enterprise, which is suitable for comprehensive promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1. It is a top view of the medium frequency furnace water circulation monitoring device of the present invention;

[0020] Figure 2 This is a front view of the medium frequency furnace water circulation monitoring device of the present invention;

[0021] Figure 3 It is a side view of the medium frequency furnace water circulation monitoring device of the present invention;

[0022] Figure 4 This is a diagram of the internal structure of the magnetic isolation housing of the present invention;

[0023] Figure 5 This is a top view of the medium frequency furnace water circulation monitoring device of the present invention. Figure 2 ;

[0024] Figure 6 The main view of the medium frequency furnace water circulation monitoring device of the present invention is Figure 2 ;

[0025] Figure 7 This is a side view of the medium frequency furnace water circulation monitoring device of the present invention. Figure 2 . DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, 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 intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. Example 1

[0027] like Figure 1-Figure 4 As shown:

[0028] The water circulation monitoring device of the medium frequency furnace, the medium frequency furnace 1 is provided with a water circulation system, the water circulation system includes a main water inlet pipe 2, a main water outlet pipe 3, a branch water inlet pipe 21 and a branch water outlet pipe 31, each main water inlet pipe 2 is provided with a row of branch water inlet pipes 21 between the medium frequency furnace 1, each main water outlet pipe 3 is provided with a row of branch water outlet pipes 31 between the medium frequency furnace 1, characterized in that the branch water inlet pipe 21 and the branch water outlet pipe 31 have a high installation structure at two ends and a low installation structure in the middle, and a metering device is provided at the lower end of the branch water inlet pipe 21 and the branch water outlet pipe 31, and the metering device includes a flow meter 22-1, a thermometer 22-2 and a pressure gauge 22-3, and an electromagnetic Valve 23, flow meter 22-1, thermometer 22-2, pressure gauge 22-3 and solenoid valve 23 are connected and communicated with the controller through a wired transmission cable. The flow meter 22-1, thermometer 22-2 and pressure gauge 22-3 are installed with a magnetic-proof housing 22. The solenoid valve 23 and the throttle valve are installed with a magnetic-proof housing. The wired transmission cable is equipped with an anti-magnetic pipe sleeve. The structure of the branch water outlet pipe 31 is the same as that of the branch water inlet pipe 21. The flow meter 22-1, thermometer 22-2 and pressure gauge 22-3 are all equipped with a communication module. The controller receives the flow, temperature and pressure of each branch water inlet pipe 21 and branch water outlet pipe 31. The controller is connected to and controls the solenoid valve 23. The controller includes a PLC board and a display screen. The PLC board is connected to the display screen. The flow meter 22-1, the thermometer 22-2, the pressure gauge 22-3 and the solenoid valve 23 are connected to the PLC board through a wired transmission cable. The controller is connected to the central control room for communication. The flow meter 22-1, the thermometer 22-2 and the pressure gauge 22-3 in the present invention can be replaced by an integrated flow meter. The controller is connected to the central control room. The field controller receives the flow, temperature and pressure of each branch water inlet pipe and branch water outlet pipe, and calculates the flow difference, temperature difference and pressure difference of each water inlet pipe and the corresponding water outlet pipe. If these detection values ​​and differences exceed a certain range, an alarm is issued. The field controller controls the solenoid valve 23 to control the water flow as needed. The field controller communicates with the central control room. When the number of branch water inlet pipes and branch water outlet pipes is 13, the data collected by the controller is as follows:

[0029] Example 2

[0030] like Figure 5-Figure 7 As shown:

[0031] The branch water inlet pipe and the branch water outlet pipe have the same structure. Water pipes are installed before and after the flow meters in the branch water inlet pipe and the branch water outlet pipe. The water pipe of the branch water inlet pipe 21 is a straight pipe I2-1 connected to the arc-shaped water pipe I2-2, and the arc-shaped water pipe I2-2 is connected to the straight pipe II2-3. The right side of the straight pipe II2-3 is the tangent direction of the end of the arc-shaped water pipe I2-2. The left side of the straight pipe II2-3 is the curved pipe II2-4. The curved pipe II2-4 is connected to the straight pipe III2-5. The straight pipe II2-3 and the straight pipe III2-5 are both installed in the tangent direction of the end of the curved pipe II2-4. The metering device is installed on the straight pipe II2-3. The curved pipe II2-4 is formed by connecting two quarter-circular pipes.

[0032] We conducted experiments in four ways.

[0033] Method 1: The straight pipe in the water inlet direction of the flow meter is connected to another straight pipe at a 90-degree angle. The total length of the two straight pipes is 1.5 meters.

[0034] Method 2: The straight pipe in the water inlet direction of the flow meter is connected to another straight pipe at an angle of 120 degrees. The total length of the two straight pipes is 1.5 meters.

[0035] Method 3: Connect the straight pipe in the water inlet direction of the flow meter to an arc-shaped water pipe. The installation direction of the straight pipe is the tangent direction of the end of the arc. The length of the straight pipe plus the arc is 1.5 meters.

[0036] Method 4: The straight pipe in the water inlet direction of the flow meter is 1.5 meters;

[0037] For the above four connection methods, the water outlet direction of the flow meter is a straight pipe, and the length of the straight pipe is 1 meter.

[0038] The above four types of water pipes were tested at water pressures of 0.05MP, 0.1MP, 0.15MP, 0.2MP, 0.25MP, and 0.3MP, respectively. 20 measurements were performed to obtain 20 sets of error data, which were then averaged and shown in the table.

[0039] Table: Error table (percentage)

[0040] pressure 0.05MP 0.1MP 0.15MP 0.2MP 0.25MP 0.3MP Method 1 90 degree bend 8.26 10.07 11.90 13.81 15.77 17.42 Method 2 120 degree bend 3.54 4.15 4.82 5.53 6.19 7.27 Method 3 Arc method plus straight pipe 0.92 1.03 1.06 1.10 1.12 1.13 Method 4 Straight pipe 0.78 0.84 0.93 0.89 0.94 0.98

[0041] It can be seen that the use of arc + straight line method can effectively reduce measurement errors in a narrow installation space. Example 3

[0042] like Figure 7 As shown:

[0043] Before installing the flowmeters for the water inlet and outlet pipes, selecting two flowmeters with the closest errors can effectively improve the measurement accuracy of the inlet and outlet flow difference of each water outlet pipe.

[0044] In the safety monitoring of medium frequency furnaces, an important indicator is to monitor the flow difference between the inlet and outlet of a water distribution pipe. Generally, instruments have errors. For example, if the industrial flow meter is 1%, the flow difference between the inlet and outlet pipes may reach 2%. In order to achieve the effect of rapid cooling, the pressure of the water distribution pipe is relatively high, the water flow rate is relatively fast, and the water volume is relatively large. Due to the measurement error of up to 2%, a slight rupture in a local part of the water distribution pipe may not be detected. Our method is: connect a batch of flow meters to the same water channel for measurement, and according to the measurement data, combine these batches of flow meters in pairs, and select the two water meters with the closest flow counts as a group. In this way, the errors of the two water meters are close, and the error of measuring the difference between the inlet and outlet flow of a water distribution pipe is very low.

[0045] According to this method, we conducted experiments. Group A is two meters that were not selected and paired as the inlet and outlet flow meters of a water distribution pipeline. Group B is two meters that were selected using our method and used as the inlet and outlet flow meters of a water distribution pipeline.

[0046] Flow rate / flow difference 1 ton 5 tons 10 tons 20 tons 50 tons 100 tons Group A 15.27Kg 76.19Kg 151.43Kg 293.8Kg 742.8Kg 1427.63Kg Group B 0.24Kg 1.21Kg 2.37Kg 3.98Kg 11.35Kg 22.28Kg

[0047] It can be seen that this method can effectively reduce the measurement error of flow difference, effectively improve the probability of accurate alarm, reduce the false alarm rate, and reduce the economic losses caused by false alarms and missed alarms.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A water circulation monitoring device for an intermediate frequency furnace, wherein the intermediate frequency furnace (1) is provided with a water circulation system, the water circulation system comprising a main water inlet pipe (2), a main water outlet pipe (3), a branch water inlet pipe (21) and a branch water outlet pipe (31), a row of branch water inlet pipes (21) being provided between each main water inlet pipe (2) and the intermediate frequency furnace (1), and a row of branch water outlet pipes (31) being provided between each main water outlet pipe (3) and the intermediate frequency furnace (1), characterized in that: The branch water inlet pipe (21) and the branch water outlet pipe (31) have an installation structure with high ends and low middle. A metering device is provided at the lower end of the branch water inlet pipe (21) and the branch water outlet pipe (31). The metering device comprises a flow meter (22-1), a thermometer (22-2) and a pressure gauge (22-3). The branch water inlet pipe (21) is provided with a solenoid valve (23). The flow meter (22-1), the thermometer (22-2), the pressure gauge (22-3) and the solenoid valve (23) are connected to the controller via a wired transmission cable. The flow meter (22-1), the thermometer (22-2), and the pressure gauge (22-3) are installed with a magnetic-proof housing (22), the wired transmission cable is equipped with a magnetic-proof sleeve, the structure of the branch water outlet pipe (31) is the same as the structure of the branch water inlet pipe (21), the flow meter (22-1), the thermometer (22-2), and the pressure gauge (22-3) are all equipped with a communication module, the controller receives the flow, temperature, and pressure of each branch water inlet pipe (21) and the branch water outlet pipe (31), and the controller is connected to and controls the solenoid valve (23); In order to minimize the impact of the narrow installation environment of the flow meter on the measurement accuracy of the flow meter, the front and rear end water distribution pipes of the flow meter (22-1) are arc-shaped, and a straight pipe in the tangential direction is connected to the interface of the arc section; The water pipe of the water inlet pipe (21) is a straight pipe I (2-1) connected to an arc-shaped water pipe I (2-2), the arc-shaped water pipe I (2-2) connected to a straight pipe II (2-3), the right side of the straight pipe II (2-3) is the tangent direction of the end of the arc-shaped water pipe I (2-2), the left side of the straight pipe II (2-3) is a curved pipe II (2-4), the curved pipe II (2-4) is connected to a straight pipe III (2-5), the straight pipe II (2-3) and the straight pipe III (2-5) are both installed in the tangent direction of the end of the curved pipe II (2-4), and the metering device is installed on the straight pipe II (2-3); The branch water inlet pipe (21) and the branch water outlet pipe (31) are U-shaped or have a structure with either end being high and the middle being low, and the metering device is installed in the low middle area, and the low middle area is required to be horizontal and have a certain length to ensure accurate flow meter measurement; The controller comprises a PLC board and a display screen, the PLC board is connected to the display screen, and the flow meter (22-1), the thermometer (22-2), the pressure gauge (22-3) and the solenoid valve (23) are connected to the PLC board via a wired transmission cable; The controller is connected to the central control room, and the controller communicates with the central control room. The central control room is equipped with a host computer to summarize, store and analyze the monitoring data of all medium frequency furnaces in the factory.

2. The medium frequency furnace water circulation monitoring device according to claim 1 is characterized in that: The flow meter (22-1) is a vortex flow meter.

3. The medium frequency furnace water circulation monitoring device according to claim 1 is characterized in that: The integrated flow meter replaces the flow meter (22-1), the thermometer (22-2) and the pressure meter (22-3), and can simultaneously detect output temperature, pressure and flow.

4. The medium frequency furnace water circulation monitoring device according to claim 1 is characterized in that: Before installing the flowmeters for the branch water inlet pipes and their corresponding branch water outlets, select two flowmeters with the closest errors.

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