Intermediate frequency furnace power distribution cabinet cooling water leakage alarm device

Abstract

The utility model discloses a cooling water leakage alarm device for a power distribution cabinet of an intermediate frequency furnace, which comprises a power distribution cabinet body, a plurality of groups of cooling water circulation system main pipelines are arranged in the power distribution cabinet body, and a water blocking groove is arranged in the cabinet body below each group of cooling water circulation system main pipeline. The water blocking groove is used for receiving and converging water drops dripping in a main pipeline of the cooling water circulation system, the two ends of the water blocking groove are high, the middle of the water blocking groove is low, a water outlet hole is formed in the center of the bottom face of the water blocking groove, at least one water leakage induction line is arranged below the water blocking groove and used for sensing the water drops dripping in the water blocking groove, and each water leakage induction line is connected with a miniature potentiometer. And a normally open contact of the micro potentiometer is arranged in a sound-light alarm circuit in parallel.

Description

Technical Field

[0001] The utility model relates to a cooling water leakage alarm device for a medium frequency furnace power distribution cabinet, belonging to a safety interlocking protection device for a medium frequency furnace. Background Art

[0002] The medium frequency induction furnace is a power supply device that converts 50Hz AC power into medium frequency (300Hz to 1000Hz), rectifies three-phase AC power into DC power, and then converts DC power into adjustable medium frequency current, which supplies the medium frequency alternating current flowing through the capacitor and induction coil, generates high-density magnetic lines in the induction coil, cuts the metal material contained in the induction coil, generates large eddy currents in the metal material, and uses the principle of electromagnetic induction to heat the metal and melt it into a high-temperature liquid. It has the advantages of high thermal efficiency, short smelting time, less alloy element burnout, wide smelting material, low environmental pollution, and can accurately control the temperature and composition of the metal liquid. During the operation of the medium frequency furnace, the current value of the thyristor, inductor coil, reactor coil, capacitor, and other main components is 200A-7000A, which will generate a lot of heat. The heat generated by the electrical components in the distribution cabinet needs to be cooled by circulating water, and the circulating water pressure is 0.2MPa-0.25MPa. The cooling system of the medium frequency furnace mainly cools the power supply and the furnace body. The power supply part includes various power supply devices and electric heating capacitors in the power cabinet. The power supply part is composed of precision electrical components. The cooling pipe is relatively thin. In order to prevent the scale in the pipe from clogging the pipe, softened water or pure water is generally used. The electric furnace and power supply use independent cooling devices. The medium frequency power supply uses a fully enclosed cooling device, and the furnace body uses a fully enclosed cooling device.

[0003] The purpose of using two independent cooling devices is to avoid mutual influence. Because the medium frequency power supply requires low-temperature cooling water, the outlet water temperature must be controlled within 55°C, but the cooling water temperature of the electric furnace induction coil can be slightly higher, which can improve the thermal efficiency of the electric furnace and reduce the size of the cooling device, thereby reducing the cost.

[0004] The following problems exist in actual production on site:

[0005] 1. Because the main line of the cooling water circulation system in the medium frequency induction circuit distribution cabinet is connected to each component with a rubber hose and a stainless steel pipe clamp, the water pipe falls off due to temperature changes and aging of the rubber hose during operation, and the cooling water splashes onto the charged components to form a circuit short circuit, thereby burning the components in the medium frequency furnace distribution cabinet and causing the medium frequency furnace to stop production.

[0006] 2. The electrical components in the medium-frequency induction circuit distribution cabinet include 76 pieces such as capacitors, rectifier KP thyristors, fast recovery diodes, cooling water jackets, etc. Each component has two water inlet and outlet connectors. Therefore, each set of medium-frequency induction furnace distribution cabinet has 110 rubber hoses and 220 connectors, and there is a great risk of the rubber hose connectors falling off.

[0007] 3. Every time a water pipe falls off, it causes damage to the components of the medium frequency furnace distribution cabinet. The inspection and repair by personnel takes about four hours, and the cost of damaged components alone is about 40,000 yuan per year.

[0008] 4. Through on-site observation, it is found that rubber hoses generally leak before falling off. Therefore, in order to avoid accidents of rubber hose falling off and to detect them in advance, the operation and maintenance personnel are required to inspect the cooling water pipes in the distribution cabinet once every 2 hours to see if there is any leakage, which increases labor costs. Due to problems such as the lack of responsibility of personnel inspections, such accidents cannot be completely prevented from happening.

[0009] 5. Since the voltage of the distribution cabinet is 575V when it is in operation, there are certain safety risks when personnel conduct inspections.

[0010] 6. Since the medium frequency induction furnace runs with a large current, if the cooling water splashes onto the rectifier element, a high voltage trip may even occur, causing a large-scale power outage in the park. Summary of the invention

[0011] The purpose of the utility model is to provide a cooling water leakage alarm device for a medium frequency furnace distribution cabinet, which can realize dripping alarm, achieve early detection and early warning, prevent the cooling water splashing after the rubber hose falls off and cause damage to electrical components, and ensure stable production operation.

[0012] The technical solution adopted by the utility model is a cooling water leakage alarm device for a medium frequency furnace power distribution cabinet, comprising a power distribution cabinet body, wherein a plurality of cooling water circulation system main lines are arranged in the power distribution cabinet body, a water retaining groove is arranged in the cabinet body below each group of cooling water circulation system main lines, for receiving and gathering water droplets dripping from the cooling water circulation system main lines, the water retaining groove is high at both ends and low in the middle, a water outlet is arranged at the center of the bottom surface of the water retaining groove, at least one water leakage sensing line is respectively arranged below the water retaining groove for sensing water droplets dripping from the water retaining groove, a miniature potentiometer is respectively connected to the water leakage sensing line, and the normally open contacts of the miniature potentiometer are arranged in parallel in an audible and visual alarm circuit.

[0013] Working principle of the utility model: Cooling water leakage mostly occurs at the water cooling joint of electrical appliances. Water seepage cannot be detected in time by naked eyes. Water seepage gradually expands and eventually leads to circuit conduction, resulting in short circuit and damage to components. This scheme adopts the use of leakage current alarm device. The alarm device is equipped with a set of induction line interfaces for connecting the leakage induction line. When the induction line is conducted and reaches the threshold, a loop is formed to return data to the device, so that the device issues a warning. The principle is that when water or other conductive liquids leak, the liquid touches the sensor (induction line) to cause the resistance of the induction line to change. The special controller converts the change in resistance into current and voltage values, thereby driving the alarm circuit and relay circuit to activate the alarm. Through the first simulation of water leakage, it is found that the alarm system is normal when the equipment is not turned on, but when the intermediate frequency furnace is turned on, the alarm system alarms for a long time and does not achieve the desired effect. The reason is that when the intermediate frequency furnace is turned on, the intermediate frequency furnace is turned on. The components of the frequency furnace generate a certain electromagnetic field that forces a weak current on the induction line, causing the alarm to malfunction. By re-modifying and adding a miniature potentiometer to filter the small current generated by the equipment, and testing and adjusting the resistance of the potentiometer after the modification, the false alarm problem can be perfectly solved. At this stage, the power indicator light of the equipment is always on; when the equipment detects a water leakage, the long-open contact set inside the controller closes, the water leakage warning light will light up, and the buzzer inside the equipment will sound a water leakage warning sound. After the long-open contact is closed, the external 220v AC contactor is closed, and the external 380V sound and light alarm sounds. When the alarm occurs, the production personnel can stop the equipment as soon as possible and deal with the water leakage after the power outage, which is safe and quick.

[0014] Effects of the utility model:

[0015] 1. After being installed at the production site, the utility model can monitor the power distribution cabinet of the medium frequency induction furnace in real time. Each time an early warning is issued, it is the phenomenon of water dripping at the joint of the rubber hose, which completely prevents the occurrence of accidents such as electrical short circuit and damage to components caused by the shedding of water pipes, ensures the stable operation of production, and improves the production efficiency of the medium frequency induction furnace by about 13%.

[0016] 2. The maintenance personnel were required to inspect the power distribution cabinet of the medium-frequency induction furnace every 2 hours, which reduced the labor intensity and saved about 150,000 yuan in labor costs.

[0017] 3. It saves the consumption of spare parts, and can save about 40,000 yuan in spare parts costs throughout the year.

[0018] 4. It eliminates the potential safety hazards of inspections by transportation and maintenance personnel and the risk of large-scale power outages in the park caused by high-voltage tripping. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the main structure of the utility model. Implementation

[0020] A cooling water leakage alarm device for a medium frequency furnace power distribution cabinet, such as Figure 1 As shown, it includes a power distribution cabinet body 1, in which a plurality of groups of cooling water circulation system main lines 2 are arranged, and a water retaining groove 7 is arranged in the cabinet body below each group of cooling water circulation system main lines, so as to receive and gather water drops dripping from the cooling water circulation system main lines, the water retaining groove 7 is high at both ends and low in the middle, and a water outlet is arranged at the center of the bottom surface of the water retaining groove, and at least one water leakage sensing line 6 is arranged below the water retaining groove to sense the water drops dripping from the water retaining groove 7, and a miniature potentiometer 3 is connected to the water leakage sensing line 6, and the normally open contact 4 of the miniature potentiometer 3 is arranged in parallel in an audible and visual alarm circuit 5.

Claims

1. A cooling water leakage alarm device for a medium frequency furnace power distribution cabinet, comprising a power distribution cabinet body, wherein a plurality of cooling water circulation system main lines are arranged in the power distribution cabinet body, and the characteristics are: A water retaining trough is arranged in the cabinet under each group of cooling water circulation system main lines to receive and gather water droplets dripping from the cooling water circulation system main lines. The water retaining trough is high at both ends and low in the middle, and a water outlet is arranged at the center of the bottom surface of the water retaining trough. At least one water leakage sensing line is arranged under the water retaining trough to sense water droplets dripping from the water retaining trough. A miniature potentiometer is connected to each water leakage sensing line, and the normally open contacts of the miniature potentiometer are arranged in parallel in an audible and visual alarm circuit.

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