Explosion-proof three-phase asynchronous motor

Abstract

The invention relates to the technical field of motors, and discloses an explosion-proof three-phase asynchronous motor which comprises a motor shell, a support and a gas storage tank, a gas storage groove is formed in the inner side of the motor shell, a plurality of one-way nozzles are fixedly connected to the inner wall of the motor shell, a connecting pipe is installed on one side of the gas storage tank, and the gas storage tank is fixedly connected with the support. The top of the motor shell is fixedly connected with an exhaust pipe, and a flow control valve is installed on the exhaust pipe. The device can inject carbon dioxide into the motor shell, flame caused by motor fire is prevented from spreading to the outside of the motor, fire disasters or explosion caused by the contact of the flame with dust and combustible gas in the external environment is prevented, the concentration of the combustible gas in the motor shell can be reduced, and therefore explosion is prevented, and the service life of the motor is prolonged. And in addition, the interior of the motor shell is cooled in a gradient mode, motor part damage caused by instant violent cooling during carbon dioxide fire extinguishing is avoided, the motor can be restarted without large-scale maintenance after fire extinguishing, and the maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electric motors, and in particular to a flameproof three-phase asynchronous motor. Background Art

[0002] A three-phase asynchronous motor is a type of induction motor powered by three phases of 380V AC (120-degree phase shift). Because the rotor and the stator's rotating magnetic field rotate in the same direction but at different speeds, slip occurs, hence the name. The rotor speed of a three-phase asynchronous motor is lower than that of the rotating magnetic field. The relative motion between the rotor winding and the magnetic field generates electromotive force and current, which interacts with the magnetic field to produce electromagnetic torque, achieving energy conversion. Compared with single-phase asynchronous motors, three-phase asynchronous motors offer superior performance and can save on various materials. Three-phase asynchronous motors can be categorized as cage-type or wound-type depending on their rotor structure. Flameproof three-phase asynchronous motors are specialized motors designed for use in flammable and explosive environments. Their core feature is a special structural design that prevents internal explosions from triggering secondary explosions in the external environment, ensuring safe operation of equipment in hazardous locations.

[0003] The existing Chinese patent announcement number (CN113241889B) is a flameproof three-phase motor, which includes a base, a shock absorption mechanism and a motor structure. The motor structure is installed on the base, and a junction box is provided at the upper middle end of the motor structure. Fixed side panels are provided on both sides of the protective panel, and a front sealing plate is provided in the center of the protective panel. The device adopts a layered flameproof structure, which not only has high material strength and higher flameproof strength, but also is safer and more reliable to use, and users can use it with more confidence. At the same time, the rear of the motor structure is convenient for heat dissipation.

[0004] With respect to the above-mentioned and existing related technologies, the inventors believe that the following defects often exist: the motor may spontaneously combust during operation due to reasons such as excessive load. Although the explosion-proof motor can block the flame generated by the explosion, if the motor spontaneously combusts, the flame may spread to the outside of the motor, thereby causing a fire or exploding upon contact with dust and combustible gases in the external environment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the existing technology has the disadvantages that the motor may spontaneously combust and easily cause a fire or explode when in contact with dust and combustible gases in the external environment. For this reason, we propose a flameproof three-phase asynchronous motor.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solution: a flameproof three-phase asynchronous motor, comprising a motor housing, a bracket and an air storage box, the motor housing and the air storage box are fixedly connected to the bracket, an air storage tank is provided on the inner side of the motor housing, a plurality of one-way nozzles are fixedly connected to the inner wall of the motor housing, the air inlet end of the one-way nozzle passes through the air storage tank, a connecting pipe is installed on one side of the air storage box, the air inlet end of the connecting pipe is fixedly connected to the motor housing and passes through the air storage tank, an exhaust pipe is fixedly connected to the top of the motor housing, the lower end of the exhaust pipe passes through the inner cavity of the motor housing, a flow control valve is installed on the exhaust pipe, a temperature sensor is fixedly connected to the inner wall of the motor housing, and a gas sensor is fixedly connected to the inner wall of the motor housing.

[0007] Preferably, a stator and a rotor are installed inside the motor housing, the rotor is rotatably connected to the inside of the stator, and the stator and the rotor correspond to the one-way nozzle.

[0008] Preferably, the air storage tank is arranged at the bottom of the inner side of the motor housing and is arranged opposite to the stator in an upper and lower position. The shape of the air storage tank is a quarter circle. Several of the one-way nozzles are arranged in the middle of the bottom of the inner side of the motor housing and are arranged opposite to the stator and rotor in an upper and lower position. Several of the one-way nozzles are divided into several groups and distributed in a quarter circle shape.

[0009] Preferably, the air storage tank is in a full-circular shape, and the air storage tank is arranged at the tail end of the motor housing and axially opposite to the stator and rotor. Several of the one-way nozzles are circumferentially arranged at the tail end of the motor housing and axially opposite to the stator and rotor.

[0010] Preferably, an air cooler is installed at the tail end of the motor housing, and the air cooler draws external air into the interior of the motor housing and makes the air flow axially inside the motor housing.

[0011] Preferably, a pressure pump is fixedly connected to the top of the bracket, the output end of the pressure pump is fixedly connected to the side wall of the air storage box and penetrates into the inner cavity, and a heating wire is fixedly connected to the inside of the connecting pipe.

[0012] Preferably, a porous plate flame arrester is fixedly connected to the interior of the exhaust pipe, and the aperture of the porous plate flame arrester is less than 1 mm.

[0013] Technical effects and advantages of the present invention:

[0014] In the present invention, carbon dioxide can be injected into the interior of the motor housing to cool the components inside the motor housing and extinguish the fire, thereby preventing the flame of the motor fire from spreading to the outside of the motor and causing a fire, or preventing the flame from contacting dust and combustible gases in the external environment and exploding. In addition, the concentration of combustible gases inside the motor housing can be reduced, thereby preventing explosion.

[0015] In the present invention, gaseous carbon dioxide can be sprayed first, and then liquid carbon dioxide can be sprayed. By utilizing the characteristic that the gaseous temperature of carbon dioxide is higher than that of liquid carbon dioxide, the temperature reduction gradient can be controlled to avoid damage to motor components caused by instantaneous and drastic temperature reduction during carbon dioxide fire extinguishing. After the fire is extinguished, the motor can be restarted without large-scale maintenance, thereby reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The disclosure of the present invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the drawings, the same reference numerals are used to refer to the same components:

[0017] Figure 1 The overall structure of the present invention is shown in FIG. Figure 1 ;

[0018] Figure 2 The overall structure of the present invention is shown in FIG. Figure 2 ;

[0019] Figure 3 This is a schematic structural diagram of a first embodiment of a motor housing according to the present invention;

[0020] Figure 4 This is a schematic structural diagram of a second embodiment of a motor housing according to the present invention;

[0021] Figure 5 A planar side sectional view of a first embodiment of a motor housing according to the present invention;

[0022] Figure 6 It is a planar cross-sectional view of the one-way nozzle of the present invention;

[0023] Figure 7 It is a structural cross-sectional view of the connecting pipe in the present invention.

[0024] Legend: 1. Motor housing; 2. Bracket; 3. Air tank; 4. Air storage tank; 5. One-way nozzle; 6. Connecting pipe; 7. Exhaust pipe; 8. Flow control valve; 9. Temperature sensor; 10. Gas sensor; 11. Stator; 12. Rotor; 13. Air cooler; 14. Booster pump; 15. Heating wire; 16. Porous plate flame arrester. DETAILED DESCRIPTION

[0025] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention and should not be regarded as the entire invention or as a limitation or restriction of the technical solution of the present invention.

[0026] Example 1

[0027] Reference Figure 1-7 As shown, the present invention provides a technical solution: a flameproof three-phase asynchronous motor, comprising a motor housing 1, a bracket 2 and an air storage tank 3, the motor housing 1 and the air storage tank 3 are fixedly connected to the bracket 2, an air storage tank 4 is opened on the inside of the motor housing 1, a plurality of one-way nozzles 5 are fixedly connected to the inner wall of the motor housing 1, the air inlet end of the one-way nozzle 5 passes through the air storage tank 4, a connecting pipe 6 is installed on one side of the air storage tank 3, the air inlet end of the connecting pipe 6 is fixedly connected to the motor housing 1 and passes through the air storage tank 4, and the top of the motor housing 1 is fixedly connected to the exhaust Tube 7, the lower end of the exhaust pipe 7 passes through the inner cavity of the motor housing 1, and a flow control valve 8 is installed on the exhaust pipe 7. A stator 11 and a rotor 12 are installed on the inside of the motor housing 1. The rotor 12 is rotatably connected to the inside of the stator 11. The stator 11 and the rotor 12 correspond to the one-way nozzle 5. When the stator 11 and the rotor 12 inside the motor are overheated or on fire, the carbon dioxide in the gas storage tank 3 is injected through the connecting pipe 6 into the gas storage tank 4, and the carbon dioxide is ejected through the one-way nozzle 5 to cool and extinguish the stator 11, the rotor 12 and other components.

[0028] A temperature sensor 9 is fixedly connected to the inner wall of the motor housing 1. The temperature sensor 9 preferably adopts an integrated digital sensor (such as MAX31825, TMP117 model). If it is used in a high-temperature environment such as metallurgy and chemical industry, it can be replaced with an industrial-grade thermocouple module (such as MAX31855+K-type thermocouple), which can withstand higher temperatures. A gas sensor 10 is fixedly connected to the inner wall of the motor housing 1. The gas sensor 10 preferably adopts an infrared sensor (such as MH-410D model). The temperature sensor 9 and the gas sensor 10 are both electrically connected to the flow control valve 10. The temperature sensor 9 can set two thresholds. The temperature sensor 9 adopts a dual set point type, which can set a first threshold and a second threshold. The value of the second threshold is higher than the first threshold. When the temperature sensor 9 detects that the temperature inside the motor housing 1 slowly rises to the first threshold, the temperature of components such as the stator 11 and the rotor 12 is too high. The motor can still run but needs to be cooled. At this time, the flow control valve 8 is half open, so that the one-way nozzle 5 sprays carbon dioxide at a small flow rate to continuously cool the components. When the temperature continues to rise rapidly and exceeds the first threshold to reach the second threshold, it is a fire, and the motor stops running due to the fire. At this time, the flow control valve 8 is fully open, and carbon dioxide is sprayed at the maximum flow rate to quickly extinguish the stator 11. The gas sensor 10 can monitor the concentration of combustible gas inside the motor housing 1. When the concentration is too high, the flow control valve 8 is half open to allow the one-way nozzle 5 to spray carbon dioxide to reduce the concentration of combustible gas inside the motor housing 1, thereby avoiding the explosion caused by excessive gas concentration inside the motor.

[0029] An air reservoir 4 is located at the bottom of the inside of the motor housing 1, vertically opposite the stator 11. The reservoir 4 is shaped like a quarter circle. Several one-way nozzles 5 are located in the middle of the bottom of the motor housing 1, vertically opposite the stator 11 and rotor 12. The nozzles 5 are arranged in groups and arranged in a quarter circle. Carbon dioxide is ejected upward from the bottom. Leveraging its greater density than air, carbon dioxide accumulates upward from the bottom, gradually squeezing hot air out through a micro-slit reserved at the top. This allows the carbon dioxide to fill the motor's interior more quickly, reaching a fire-extinguishing concentration and improving both fire extinguishing and cooling rates.

[0030] A porous plate flame arrester 16 is fixedly connected to the interior of the exhaust pipe 7. The apertures in the porous plate flame arrester 16 are less than 1 mm. Carbon dioxide inside the motor housing 1 can pass through the exhaust pipe 7. In the event of an explosion, some of the flame will enter the exhaust pipe 7. The flame will be extinguished due to excessive heat loss when passing through the tiny holes in the porous plate flame arrester 16, preventing the flame from being discharged outside the motor while allowing the gas to be discharged smoothly.

[0031] Example 2

[0032] Reference Figure 4As shown, the shape of the air storage tank 4 is a full circle. The air storage tank 4 is arranged at the tail end of the motor housing 1 and is axially opposite to the stator 11 and the rotor 12. Several one-way nozzles 5 are circumferentially arranged at the tail end of the motor housing 1 and are axially opposite to the stator 11 and the rotor 12. An air cooler 13 is installed at the tail end of the motor housing 1. The air cooler 13 draws external air into the interior of the motor housing 1 and makes the air flow axially inside the motor housing 1. The air cooler 13 adopts an independent driving power supply. When the motor stops running due to fire, the air cooler 13 can still operate normally. Carbon dioxide is axially injected from the end face of the stator 11 through the axially arranged one-way nozzle 5, and the air flow from the rear end to the front end of the air cooler 13 blows the carbon dioxide to flow axially inside the motor housing 1, thereby increasing the flow speed of carbon dioxide and allowing the carbon dioxide to fill the interior of the motor housing faster, thereby increasing the fire extinguishing and cooling speed.

[0033] Example 3

[0034] Reference Figure 5 As shown, a pressure pump 14 is fixedly connected to the top of the bracket 2, and the output end of the pressure pump 14 is fixedly connected to the side wall of the gas storage tank 3 and penetrates into the inner cavity. A heating wire 15 is fixedly connected to the inside of the connecting pipe 6. The flow rate is controlled by the flow control valve 8 to stabilize the pressure inside the connecting pipe 6. At the same time, the liquefied carbon dioxide in the connecting pipe 6 is heated by the heating wire 15 to convert the carbon dioxide into a gaseous state. After the gaseous carbon dioxide is ejected for a few seconds, the heating wire 15 stops heating. Then the pressure pump 14 pressurizes the liquid carbon dioxide in the gas storage tank 3 to keep the carbon dioxide in a liquid state and eject it from the one-way nozzle 5, thereby cooling the stator 11 and other components in stages. The characteristic that the gaseous temperature of carbon dioxide is higher than that of the liquid state is used to control the temperature drop gradient, thereby avoiding damage to the motor components caused by the sudden and drastic temperature drop during carbon dioxide fire extinguishing, so that the motor will not be damaged after the fire is extinguished. It can be restarted without large-scale maintenance. When extinguishing a fire, in order to ensure the fire extinguishing effect, all the carbon dioxide in the gas tank 3 is directly discharged. After the fire extinguishing is completed, carbon dioxide can be added to the gas tank 3 again. When cooling, it is a single injection. The time of each single injection is set to 15-30 seconds. The single injection amount is designed according to the mass of the stator 11 and the rotor 12. The heavier the mass of the stator 11 and the rotor 12, the larger the single injection amount. The single injection of carbon dioxide can keep the motor at a reasonable temperature for at least 30 minutes. When the carbon dioxide stored in the gas tank 3 is full, it can maintain at least 15-20 times of effective injection cooling.

[0035] Working principle: The temperature inside the motor housing 1 can be detected by the temperature sensor 9, and the concentration of the combustible gas inside the motor housing 1 can be detected by the gas sensor 8. When the temperature inside the motor housing 1 is too high, the flow control valve 8 opens, allowing the carbon dioxide in the gas storage box 3 to enter the gas storage tank 4 through the connecting pipe 6, and the carbon dioxide is sprayed out through the one-way nozzle 5. The carbon dioxide cools or extinguishes components such as the stator 11 and the rotor 12 inside the motor housing 1, preventing the flame of the motor fire from spreading to the outside of the motor, preventing fire, or preventing the flame from coming into contact with dust and combustible gas in the external environment and exploding. When it is detected that the concentration of combustible gas is too high, the flow control valve 8 will also open to allow the one-way nozzle 5 to spray carbon dioxide into the motor housing 1, reducing the concentration of combustible gas inside the motor housing, thereby preventing explosion.

[0036] The temperature sensor 9 detects the rate of temperature rise and the value reached, and controls the flow control valve 8 to be half open or fully open. If the temperature inside the motor housing 1 slowly rises to a first threshold value, the one-way nozzle 5 is half open, and carbon dioxide is sprayed at a small flow rate to continuously cool the components. When the temperature continues to rise rapidly and reaches the second threshold value, it is a fire, and the motor stops running due to the fire. At this time, the one-way nozzle 5 is fully open, and carbon dioxide is sprayed at the maximum flow rate to extinguish the stator 11 with all its strength.

[0037] The flow rate is controlled by the flow control valve 8 to stabilize the pressure inside the connecting pipe 6. At the same time, the liquefied carbon dioxide in the connecting pipe 6 is heated by the heating wire 15 to convert the carbon dioxide into a gaseous state. After the gaseous carbon dioxide is ejected for a few seconds, the heating wire 15 stops heating. Then, the pressure pump 14 pressurizes the liquid carbon dioxide in the gas storage tank 3 to keep the carbon dioxide in a liquid state and eject it from the one-way nozzle 5, thereby cooling the stator 11 and other components in stages. By utilizing the characteristic that the gaseous temperature of carbon dioxide is higher than that of the liquid state, the temperature reduction gradient is controlled to avoid damage to the motor components caused by the instantaneous and drastic temperature drop during carbon dioxide fire extinguishing. After the fire is extinguished, the motor can be restarted without large-scale maintenance, thereby reducing maintenance costs.

[0038] The technical scope of the present invention is not limited to the contents of the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of ​​the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A flameproof three-phase asynchronous motor, characterized in that: It includes a motor housing, a bracket and an air storage tank, the motor housing and the air storage tank are both fixedly connected to the bracket, an air storage tank is opened on the inner side of the motor housing, a plurality of one-way nozzles are fixedly connected to the inner wall of the motor housing, the air inlet end of the one-way nozzle passes through the air storage tank, a connecting pipe is installed on one side of the air storage tank, the air inlet end of the connecting pipe is fixedly connected to the motor housing and passes through the air storage tank, an exhaust pipe is fixedly connected to the top of the motor housing, the lower end of the exhaust pipe passes through the inner cavity of the motor housing, a flow control valve is installed on the exhaust pipe, a temperature sensor is fixedly connected to the inner wall of the motor housing, and a gas sensor is fixedly connected to the inner wall of the motor housing.

2. The flameproof three-phase asynchronous motor according to claim 1, characterized in that: A stator and a rotor are installed inside the motor housing. The rotor is rotatably connected to the inside of the stator. The stator and the rotor correspond to the one-way nozzle.

3. The flameproof three-phase asynchronous motor according to claim 1, characterized in that: The air storage tank is arranged at the bottom of the inner side of the motor housing and is arranged opposite to the stator in the upper and lower directions. The shape of the air storage tank is a quarter circle. Several one-way nozzles are arranged in the middle of the bottom of the inner side of the motor housing and are arranged opposite to the stator and rotor in the upper and lower directions. Several one-way nozzles are divided into several groups and distributed in the shape of a quarter circle.

4. The flameproof three-phase asynchronous motor according to claim 1, characterized in that: The air storage tank is in a full-circular shape and is arranged at the tail end of the motor housing and axially opposite to the stator and the rotor. Several one-way nozzles are circumferentially arranged at the tail end of the motor housing and axially opposite to the stator and the rotor.

5. The flameproof three-phase asynchronous motor according to claim 1, characterized in that: An air cooler is installed at the tail end of the motor housing. The air cooler draws external air into the motor housing and makes the air flow axially inside the motor housing.

6. The flameproof three-phase asynchronous motor according to claim 1, characterized in that: A pressure pump is fixedly connected to the top of the bracket, an output end of the pressure pump is fixedly connected to the side wall of the air storage box and penetrates into the inner cavity, and a heating wire is fixedly connected to the inside of the connecting pipe.

7. The flameproof three-phase asynchronous motor according to claim 1, characterized in that: The exhaust pipe is internally fixedly connected with a porous plate flame arrester, and the aperture of the porous plate flame arrester is less than 1 mm.

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