Analog quantity acquisition module
Through the simulation acquisition module, the IGBT module temperature and lining thickness are monitored in real time, and the problems of equipment overheating and lining damage in the medium-frequency smelting furnace are solved, achieving the improvement of equipment safety and reliability.
Patent Information
- Application Number
- CN202422209440.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-09-09
AI Technical Summary
The IGBT module in the medium frequency smelting furnace is prone to overheating and damage, and the cooling effect is unstable, making the furnace lining life difficult to accurately judge, resulting in equipment failures and safety hazards. The existing detection methods rely on manual experience and are not reliable enough.
The analog quantity acquisition module is used to detect the IGBT module temperature, lining thickness and resonant capacitor temperature, and the CPU judges and outputs early warning and alarm signals. Combined with the touch screen display, real-time monitoring and early warning of the device status are achieved.
It improves the safety and reliability of the medium-frequency smelting furnace, reduces equipment failures, avoids shutdowns and safety accidents caused by overheating or damage to the furnace lining, and improves the predictability of operations.
Smart Images
Figure CN223179326U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of intermediate frequency melting furnace detection, and particularly relates to an analog quantity acquisition module. Background Technique
[0002] As Figure 1 shown, the intermediate frequency melting furnace is composed of a furnace body and an inverter power supply. The furnace body is composed of a furnace shell 11, an induction coil 12, and a furnace lining 110. The outermost layer of the furnace body is the furnace shell 11, inside is the induction coil 12, and then inside is the heat insulation material and the furnace lining 110. The furnace lining 110 is formed by knotting refractory materials. Inside the furnace lining 110 is the molten steel. The inverter power supply is composed of a power supply 21, a rectifier circuit 22, a filter circuit 23, an IGBT module 24, a resonant capacitor 25, etc.
[0003] For the inverter power supply, the use of a high-power IGBT module 24 is the core device. Its heat resistance is relatively poor. Once the temperature is too high, it is very easy to have a thermal breakdown fault, and the price is also relatively high. Generally, high-power inverter power supplies use water cooling to dissipate heat to ensure normal operation. In actual use, affected by the on-site environment, due to the large difference in the quality of the cooling water, the cooling effect varies greatly. Some factories with better conditions will use a closed-loop cooling system, and the cooling water uses pure water. This situation is the best, and the cooling of the IGBT module is guaranteed. Some factories with relatively poor conditions will use well water or even river water. Due to the different water quality of the cooling water and the sundries in the water, it is very easy to cause poor heat dissipation of the cooling system, and ultimately lead to overheating and damage of the IGBT module.
[0004] In summary, it is very necessary to detect the temperature of the IGBT module. The common practice in the prior art is to install a temperature protection switch on the radiator of the IGBT module. When the radiator temperature reaches the action temperature of the temperature switch, an alarm is given and the machine stops to protect the IGBT from overheating and damage. However, using this method has a great disadvantage. When the temperature switch detects that the temperature is too high, the machine must stop with an alarm. At this time, if the metal in the furnace is just in a molten state, the temperature will drop due to the stop, and it will solidify together. In the light case, it will cause difficulties in starting the furnace next time and take a long time. In the heavy case, it will cause damage to the furnace lining and scrapping of a furnace of materials, resulting in relatively heavy losses.
[0005] For the furnace lining 110, its service life is generally related to the process of knotting the furnace lining 110. Since manual knotting is used, the service life of the furnace lining 110 knotted by different knotting personnel is different. Moreover, it is related to the temperature and stirring force of the molten steel. When the temperature is high and the stirring force is large, the service life of the furnace lining is short. When the temperature is low and the stirring force is small, the service life of the furnace lining 110 will be long. The stirring force is related to the working frequency and power. Generally, the service life of the furnace lining 110 is about one week to one month. As the furnace is used, the furnace lining 110 will become thinner and thinner due to the scouring of the molten steel. When the thickness is thin to a certain extent and cannot withstand the pressure of the molten steel, it will crack. Once it cracks, the molten steel will flow out. The flowing out of the molten steel will cause the induction coil to short-circuit and even damage the inverter power supply. If it is some furnaces with relatively large capacity, a large amount of high-temperature molten steel flowing out will cause the furnace to be scrapped and even cause accidents of personal injury or death.
[0006] Regarding the usage situation of the furnace lining 110, currently, generally, the furnace worker observes the thickness of the furnace lining 110 and the scouring situation of the inner wall of the furnace manually before starting the furnace. Once it is found that a certain part of the furnace lining 110 becomes thinner or has cracks or other situations, it will no longer be used and the furnace lining will be knotted again.
[0007] This method has many uncertain human factors and has a great relationship with the experience and self-judgment of the furnace worker, and is not very reliable. There is also a method of using a furnace wall thickness detection device. By arranging high-temperature-resistant electrodes at the bottom and periphery of the furnace lining 110, when the furnace lining 110 is thin to a certain extent, the electrodes contact the molten steel and form a short circuit through the molten steel, and an alarm is sent to remind the furnace worker that the service life of the furnace lining has reached and the furnace lining 110 needs to be replaced. This method largely avoids the occurrence of cracking accidents of the furnace lining 110, but there are also some problems. For example, when placing the electrodes, the position of the electrodes inside the furnace lining is very important. Once it is not accurate enough, the alarm will be sent when the service life of the furnace lining has not reached, or the alarm will not be sent when the furnace lining 110 has reached its service life. Utility Model Content
[0008] The purpose of the present utility model is to improve the safety and reliability of the intermediate frequency melting furnace during use.
[0009] In order to achieve the above-mentioned utility model purpose, the technical solution of the present utility model provides an analog quantity acquisition module for detecting the thickness of the furnace lining, the temperature of the IGBT module of the inverter power supply, and the resonant capacitor in the intermediate frequency melting furnace. The analog quantity acquisition module includes:
[0010] The input ends of the furnace lining thickness detection device are connected to the inner surface and the outer surface of the furnace lining. The output end of the lining thickness detection device is connected to the furnace lining thickness input end. The IGBT module is connected to the input end of the IGBT temperature measurement device. The output end of the IGBT temperature measurement device is connected to the IGBT temperature input end. The resonant capacitor is connected to the input end of the resonant capacitor temperature measurement device. The output end of the resonant capacitor temperature measurement device is connected to the resonant capacitor temperature input end.
[0011] The IGBT temperature input terminal, the furnace lining thickness input terminal, and the resonant capacitor temperature input terminal are all connected to the CPU. The CPU is electrically connected to the pre-alarm output terminal and the alarm output terminal through the I / O circuit and the RS485 communication circuit, and is also electrically connected to the touch screen. The pre-alarm output terminal and the alarm output terminal are respectively connected to the corresponding pre-alarm device and alarm device.
[0012] The CPU internally stores the preset pre-alarm value and the preset alarm value from the touch screen, and the CPU determines whether the input signals from the IGBT temperature input terminal, the furnace lining thickness input terminal, and the resonant capacitor temperature input terminal exceed the preset pre-alarm value and the preset alarm value.
[0013] When the preset pre-alarm value and / or the preset alarm value is exceeded, the CPU converts the input signal into a digital quantity through the I / O circuit and transmits it to the pre-alarm output terminal and / or the alarm output terminal and the touch screen via the RS485 communication circuit.
[0014] Preferably, the analog quantity acquisition module is powered by DC24V.
[0015] Preferably, the IGBT temperature measuring device is a thermistor.
[0016] Preferably, the resonant capacitor temperature measuring device is a Pt100 thermal resistor.
[0017] Preferably, both the pre-alarm output terminal and the alarm output terminal are relay contacts.
[0018] Preferably, both the pre-alarm device and the alarm device are warning devices with sound and light alarm functions.
[0019] Preferably, the preset pre-alarm value is greater than the preset alarm value.
[0020] The technical solution of the present utility model proposes an analog quantity acquisition module, which detects the working temperature of the IGBT module, the furnace lining thickness, and the resonant capacitor temperature, and displays the detected data through the touch screen. Through the alarm and pre-alarm functions, the operator can be informed in advance of the usage situation of the furnace. Description of the Drawings
[0021] Figure 1 It is a schematic diagram of the structure of an existing intermediate frequency melting furnace;
[0022] Figure 2 It is a schematic diagram of the internal circuit connection of an analog quantity acquisition module provided by an embodiment of the present utility model;
[0023] Figure 3 It is a schematic diagram of the PCB board port positions of an analog quantity acquisition module provided by an embodiment of the present utility model;
[0024] Figure 4 Schematic diagram of circuit connection during the use of an analog quantity acquisition module provided by an embodiment of the present invention. Specific embodiments
[0025] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.
[0026] As Figures 2 - 4 shown, an analog quantity acquisition module provided by an embodiment of the present invention mainly consists of a CPU, a memory, an analog quantity input circuit, an RS485 communication circuit, an I / O circuit, and a power supply circuit. It has three groups of analog quantity inputs and two groups of digital quantity outputs. The three groups of analog quantity inputs include an IGBT temperature input terminal 31, a furnace lining thickness input terminal 41, and a resonant capacitor temperature input terminal 251, which respectively collect the IGBT temperature, the furnace lining thickness, and the resonant capacitor temperature. The two groups of digital quantity outputs include a pre-alarm output terminal 51 and an alarm output terminal 52, both of which use relay contacts for output, and are respectively for pre-alarm output and alarm output.
[0027] The analog quantity acquisition module is powered by DC24V71. The analog quantity input signal is processed by the analog quantity input circuit and sent to the A / D conversion circuit of the CPU for analog-to-digital conversion. The CPU compares the converted digital quantity with the set value. If it exceeds the pre-alarm value, the pre-alarm action is output. If it exceeds the alarm value, both the alarm action and the pre-alarm action are output. At the same time, the digital quantity is transmitted to the touch screen through the RS485 circuit 61 for display.
[0028] The pre-alarm value and the alarm value are set by the touch screen and transmitted to the CPU through the RS485 circuit 61.
[0029] The analog quantity input is divided into three paths. Among them, the IGBT temperature measurement uses a thermistor, the furnace lining thickness is a 4-20mA signal, and the resonant capacitor temperature measurement uses a Pt100 thermal resistor. The two groups of outputs are relay contacts, and both normally open and normally closed are led out. The A and B of RS485 are connected to the Data+ and Data- of the touch screen.
[0030] During normal use, for the IGBT temperature and the resonant capacitor temperature, the pre-alarm value should be lower than the alarm value. When the temperature reaches the pre-alarm value, an audible and visual alarm indication is used to remind the operator. At this time, the operator can check whether the cooling water is abnormal and take corresponding measures to improve the cooling effect. For the thickness of the furnace lining, the pre-alarm value should be greater than the alarm value. For example, if the pre-alarm value is set to 8 cm and the alarm value is set to 7 cm, when the thickness of the furnace lining decreases to 8 cm, special attention should be paid to the condition of the furnace lining. This plays a role in predicting faults in advance.
Claims
1. An analog acquisition module, characterized in that, For detecting the thickness of the furnace lining in an intermediate frequency melting furnace, and the temperatures of the IGBT module and resonant capacitors of an inverter power supply. The analog quantity acquisition module includes: The inner surface and outer surface of the furnace lining are connected to the input end of the furnace lining thickness detection device. The output end of the lining thickness detection device is connected to the furnace lining thickness input end. The IGBT module is connected to the input end of the IGBT temperature measurement device. The output end of the IGBT temperature measurement device is connected to the IGBT temperature input end. The resonant capacitor is connected to the input end of the resonant capacitor temperature measurement device. The output end of the resonant capacitor temperature measurement device is connected to the resonant capacitor temperature input end. The IGBT temperature input end, the furnace lining thickness input end, and the resonant capacitor temperature input end are all connected to the CPU. The CPU is electrically connected to the pre-alarm output end and the alarm output end through the I / O circuit and the RS485 communication circuit, and is also electrically connected to the touch screen. The pre-alarm output end and the alarm output end are respectively connected to the corresponding pre-alarm device and alarm device. The CPU internally stores the preset pre-alarm value and the preset alarm value from the touch screen. The CPU determines whether the input signals at the IGBT temperature input end, the furnace lining thickness input end, and the resonant capacitor temperature input end exceed the preset pre-alarm value and the preset alarm value. When exceeding the preset pre-alarm value and / or the preset alarm value, the CPU converts the input signal into a digital quantity through the I / O circuit and transmits it to the pre-alarm output end and / or the alarm output end and the touch screen via the RS485 communication circuit.
2. The analog quantity acquisition module according to claim 1, characterized in that The analog quantity acquisition module is powered by DC24V.
3. The analog quantity acquisition module according to claim 1, characterized in that The IGBT temperature measurement device is a thermistor.
4. The analog quantity acquisition module according to claim 1, wherein The resonant capacitor temperature measurement device is a Pt100 thermal resistor.
5. The analog quantity acquisition module according to claim 1, wherein Both the pre-alarm output end and the alarm output end are relay contacts.
6. The analog quantity acquisition module according to claim 1, wherein Both the pre-alarm device and the alarm device are warning devices with a sound and light alarm function.
7. An analog quantity acquisition module as claimed in claim 1, wherein The preset pre-alarm value is greater than the preset alarm value.