A mine-used intrinsically safe lamp

Abstract

The application discloses a mine-used intrinsically safe lamp, which comprises a DC-DC step-down conversion circuit, a rectification filtering circuit, an abnormal protection circuit, a lighting circuit, the rectification filtering circuit is connected with a mine-used intrinsically safe power supply, the rectification filtering circuit comprises a three-phase rectification bridge, a phase-shifting capacitor, a phase-shifting inductor and a filtering capacitor, the DC output end of the three-phase rectification bridge is connected with the DC input end of the DC-DC step-down conversion circuit after being connected with the filtering capacitor in parallel, the abnormal protection circuit comprises a low-temperature combustible gas sensor, a fast thyristor, a coupling transformer, a current-limiting inductor, a freewheeling diode and a voltage-dependent resistor, and the lighting circuit comprises a lighting Internet of Things module, a constant-current diode, an LED lamp set, a pre-warning LED lamp set, an alarm LED lamp set, a control triode and a control triode. The application has the advantages of high reliability, low price and adaptability to low voltage.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of downhole lamps, and particularly relates to a mine-used intrinsically safe lamp. BACKGROUND

[0002] The DC power supply device and lamp used in a coal mine have special use requirements and safety requirements. With the development of intelligentization of coal mines, a large number of LED lighting lamps, underground server switch routers are used, so that the application amount of underground DC power supply equipment is greatly increased, and the deficiencies of the existing underground intrinsically safe power supply are increasingly highlighted. The main deficiencies of the existing underground intrinsically safe power supply are:

[0003] The abnormal protection circuit is extremely high in price. The intrinsically safe power supply used in a coal mine has extremely high fault tolerance requirements for itself, and requires that the output end cannot produce sparks under short circuit conditions. The existing technology collects the output current by using an analog sampling circuit with extremely high sampling speed, and quickly closes the output to realize protection after finding short circuit signs. Since the technology depends on high-speed sampling, an imported chip needs to be used, which is extremely high in cost. The price of a 1A rated current protection module is more than 70 yuan, which greatly increases the power supply procurement cost.

[0004] The voltage fluctuation adaptation ability is poor. The underground power supply system often uses 127V, and sometimes the power supply voltage is only 60-70V. Most switching power supply products cannot operate under such low voltage. In order to adapt to the low voltage working environment, the transformer and main control chip of the DC-DC converter in the power supply must be greatly improved, which greatly increases the cost. SUMMARY

[0005] In view of the above problems, the purpose of the present application is to provide a mine-used intrinsically safe lamp, which can effectively overcome the shortcomings of the prior art and has the outstanding advantages of long service life, low price and strong low voltage adaptation ability.

[0006] The technical scheme of the present application is: a mine-used intrinsically safe lamp, comprising:

[0007] A rectifier filter circuit connected with a mine-used intrinsically safe power supply, the rectifier filter circuit comprises a three-phase rectifier bridge, a phase-shift capacitor, a phase-shift inductor and a filter capacitor, an AC N-phase input end of the mine-used intrinsically safe power supply is connected with one of the AC input ends of the three-phase rectifier bridge, the AC L-phase input end of the mine-used intrinsically safe power supply is divided into two paths, one path is connected with the phase-shift capacitor in series and then connected with another AC input end of the three-phase rectifier bridge, and the other path is connected with the phase-shift inductor in series and then connected with the last AC input end of the three-phase rectifier bridge;

[0008] A DC-DC step-down conversion circuit, a DC output end of the three-phase rectifier bridge is connected with the filter capacitor in parallel, and then connected with a DC input end of the DC-DC step-down conversion circuit;

[0009] An abnormality protection circuit, the abnormality protection circuit comprises a low-temperature combustible gas sensor, a fast thyristor, a coupling transformer, a current-limiting inductor, a freewheeling diode and a voltage-dependent resistor, a positive electrode and a negative electrode of the fast thyristor are connected with positive and negative DC output ends of the DC-DC step-down conversion circuit in parallel, the low-temperature combustible gas sensor is connected in series between the positive DC output end of the DC-DC step-down conversion circuit and a gate electrode of the fast thyristor, the coupling transformer is a single-winding three-tap structure, a first tap and a second tap are connected with the positive electrode and the negative electrode of the fast thyristor in parallel, a third tap is connected with the gate electrode of the fast thyristor in series with the voltage-dependent resistor, and the current-limiting inductor is connected in series with the DC output end of the DC-DC step-down conversion circuit in parallel with the freewheeling diode;

[0010] A lighting circuit connected with the DC-DC step-down conversion circuit.

[0011] Further, the lighting circuit comprises an Internet of Things module, a constant-current diode, an LED lamp group, a pre-warning LED lamp group, an alarm LED lamp group, a control triode and a control triode, positive and negative power supply electrodes of the lighting circuit are connected with positive and negative DC output electrodes of the DC-DC step-down conversion circuit respectively, the positive power supply electrode of the lighting circuit is connected with the negative electrode of the DC-DC step-down conversion circuit in series with the constant-current diode and the lighting LED lamp group, positive and negative power supply electrodes of the Internet of Things module are connected with positive and negative power supply electrodes of the lighting circuit respectively, I / O output ends of the Internet of Things module are connected with base electrodes of the control triode and the control triode respectively, negative electrodes of the control triode and the control triode are connected with the negative power supply electrode of the lighting circuit, and collector electrodes of the control triode and the control triode are connected with the positive power supply electrode of the lighting circuit in series with the pre-warning LED lamp group and the alarm LED lamp group respectively.

[0012] Further, the DC-DC step-down conversion circuit, the rectification and filtering circuit, the abnormality protection circuit and the lighting circuit are all installed inside the explosion-proof shell.

[0013] Further, the lighting circuit further comprises an antenna, the antenna is a ring-shaped multi-coil structure, is arranged along an inner wall of the explosion-proof shell, and two ends of the antenna are further connected with an alternating current side of a multiple voltage rectification circuit, a direct current side of the multiple voltage rectification circuit is connected with positive and negative DC output electrodes of the DC-DC step-down conversion circuit, and a transmitting antenna lead-out end of the Internet of Things module is connected with one of the two ends of the antenna.

[0014] Further, the explosion-proof shell is filled with mixed liquid, the volume of the mixed liquid accounts for 90% of the volume of the cavity in the explosion-proof shell, and the mixed liquid is composed of carbon tetrachloride liquid, ferroferric oxide particles, elemental iron powder, thickening agent and suspending agent, and the mass percentage of the carbon tetrachloride liquid, the ferroferric oxide particles, the elemental iron powder, the thickening agent and the suspending agent is 20-25%, 35-40%, 40-45%, 3-4% and 5-7% respectively.

[0015] Further, the ferroferric oxide particles and the elemental iron powder have a particle size of 8000-10000 mesh.

[0016] Further, unequal air gaps are arranged between the cores of the current-limiting inductor.

[0017] Further, the filter capacitor is a film capacitor.

[0018] Compared with the prior art, the working principle and beneficial effects of the present application are as follows:

[0019] 1. Low cost: The present application breaks through the conventional idea and adopts short-circuit shunt instead of the conventional idea of quickly cutting off the short circuit, overcomes the high cost caused by the high-priced chip indispensable for rapid short circuit detection, and uses a simple and reliable passive coupling transformer to detect the voltage fluctuation of the output end. When the voltage decreases in the early stage of short circuit, the fluctuating voltage signal has been transmitted to the fast thyristor through the secondary coil, and the fast thyristor can be triggered to conduct within 10 microseconds, thereby absorbing the short circuit energy and making it impossible for the external short circuit spark to occur, thereby achieving the intrinsic safety protection effect. Since the induced electromotive force of the primary and secondary windings of the transformer is generated at the same time, the entire circuit can start protection within 10 microseconds, which is faster than the prior art of chip detection and then starting protection, and the cost is only a few yuan, thereby greatly reducing the cost of the intrinsic safety protection circuit, overcoming the problem of unstable supply of imported chips, and greatly reducing the cost of the power supply system by 60%, while breaking the dependence on imported chips, and the beneficial effects are extremely significant.

[0020] 2. High reliability: The present application uses a three-phase rectifier bridge to establish single-phase split-phase rectification, so that the ripple amplitude of the DC side of the rectifier bridge is greatly reduced, and therefore the capacitance value of the filter capacitor can be greatly reduced, so that the use of electrolytic capacitors can be avoided, and instead, high-reliability film capacitors can be used. Since the shortcoming of short service life of electrolytic capacitors is overcome, the service life and reliability of the power supply can be greatly improved. The present application uses carbon tetrachloride solution for internal filling, and uses non-flammable liquid to infiltrate and dissipate heat, which can greatly improve the internal heat conduction speed and eliminate high-temperature components, thereby doubling the service life.

[0021] 3. Stabilizing Grid Voltage: This invention takes a unique approach, not by modifying the power supply itself to adapt to the instability of the underground power supply voltage, but by utilizing a special circuit innovation of phase-splitting rectification. By using a capacitor with a capacitance slightly larger than the inductor, the entire power supply becomes a capacitive load. The inductive reactive power output of this capacitive load compensates for the reactive power of the power supply network, thereby stabilizing the network voltage. This not only protects the power supply itself from the dangers of low voltage but also further stabilizes the voltage of the underground power grid, reducing grid losses and thus lowering line losses and stabilizing the grid voltage, resulting in indirect energy-saving benefits. Furthermore, the power factor of this invention changes with the supply voltage. When the voltage is high, the current is low, the inductive reactance of the phase-shifting inductor is large, and the inductive reactive power output of the circuit is low. However, when the supply voltage drops significantly, the power supply input current increases, the saturation inductance of the phase-shifting inductor decreases, and the inductive reactive power output of the circuit increases. This achieves dynamic reactive power support during low grid voltage conditions, making this power supply an intelligent dynamic reactive power compensator, greatly improving the economic efficiency of grid operation.

[0022] 4. Proactive Dual Safety: Existing intrinsically safe power supplies only consider the absence of sparks after a fault, neglecting the inherent danger within the explosion-proof enclosure, i.e., the presence of flammable gas. Therefore, they offer only passive safety protection. This invention utilizes a low-temperature flammable gas sensor connected to a fast thyristor. When the circuit detects flammable gas inside, it automatically triggers the thyristor to shut off the power, thus improving operator safety and achieving proactive protection and safety immediately. Furthermore, the lamp is filled with carbon tetrachloride solution. When sparks occur in the lamp circuit, the carbon tetrachloride eliminates the arc, providing dual protection. In the event of an external fire or explosion, when the lamp temperature reaches 76.8 degrees Celsius, the carbon tetrachloride boils and ruptures the lamp casing. The resulting carbon tetrachloride solution extinguishes the external fire. This combination of external fire extinguishing and internal fire protection significantly improves the safety of underground operations.

[0023] 5. Simple wireless communication control and long range: Existing technologies using IoT modules to control LEDs have complex structures. Achieving color-changing alarms requires complex wiring and multiple communication channels. This invention uses a single constant current diode to drive the LED group with constant current. Multiple alarm LED groups are connected in parallel at the output of the constant current diode to achieve color-changing alarms. This way, the IoT module only needs to consider I / O outputs, not current control. As long as the voltage of the alarm red or yellow LED group is slightly lower than that of the white LED group for illumination, the white LED automatically turns off or reduces its brightness after the red or yellow LED is lit, significantly simplifying the complexity of the control circuit. The antenna ring structure of this invention surrounds the inside of the lamp, utilizing the metal of the mounting base for directional signal reflection, achieving a gain of over 8dB compared to typical built-in antennas, thus enabling communication distances of over 100m in complex underground environments.

[0024] 6. The power consumption is low, and the device vibration loss is reduced. The application utilizes the antenna annular structure around the lamp inside, the iron material powder in the carbon tetrachloride solution can form reciprocating vibration under the condition of device vibration under the action of suspending agent and thickening agent, so as to cut the magnetic line, generate induced electromotive force in the antenna coil, and supply power to the lamp after voltage boosting and rectification through the multiple voltage boosting rectification circuit. On the one hand, the power supply power can be reduced, the intrinsic safety power supply limit is broken, and the lamp energy consumption is reduced. On the other hand, the magnetic fluid power generation system with this special structure will form damping to the lamp vibration, thereby attenuating the downhole device vibration, reducing the vibration noise and loss.

[0025] 7. Convenient installation, and low-cost pre-fixing is realized. If there is a magnet pre-fixing in the downhole device, the installation convenience can be greatly improved. Since the price of magnetic material is high, it is generally impossible to use rare earth ferromagnetic material for pre-fixing, which brings inconvenience to rapid installation. The application utilizes the constant magnetic field of the ferromagnetic powder material for pre-fixing. Under the condition of the same adsorption force, the cost of magnetic material is reduced by about 3 times.

[0026] 8. Easy detection of explosion failure is realized. The explosion protection of general explosion-proof lamps is easy to fail and difficult to know. The number of downhole lamps is extremely large, and it is impossible to frequently check each lamp. Once the explosion-proof sealing of a lamp fails, it may cause hidden dangers to the safety production in the well. Since the application is filled with liquid carbon tetrachloride inside, once the shell leaks, the carbon tetrachloride liquid immediately leaks out, and the hidden danger can be found visually, thereby realizing easy detection of explosion failure. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the application;

[0028] Figure 2 It is a schematic diagram of the position of the antenna in the explosion-proof shell.

[0029] Among them, 1-DC-DC step-down conversion circuit, 2-rectifier filter circuit, 3-abnormal protection circuit, 4-three-phase rectifier bridge, 5-phase-shift capacitor, 6-phase-shift inductor, 7-filter capacitor, 8-low-temperature combustible gas sensor, 9-fast thyristor, 10-coupling transformer, 11-current limiting inductor, 12-continuation diode, 13-voltage-dependent resistor, 14-illumination circuit, 15-illumination Internet of Things module, 16-constant current diode, 17-LED lamp group, 18-prewarning LED lamp group, 19-alarm LED lamp group, 20-control triode, 21-control triode, 22-antenna, 23-explosion-proof shell, 25-multiple voltage boosting rectification circuit. DETAILED DESCRIPTION

[0030] The specific embodiments of the application will be described below in combination with the accompanying drawings. Figure 1 to the accompanying drawings Figure 2The specific embodiments of the present invention will be described in detail below. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0031] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] It should be noted that the circuit connections involved in this invention all adopt conventional circuit connection methods and do not involve any innovation.

[0033] Example: Figure 1 As shown, a mining intrinsically safe lighting fixture includes a DC-DC step-down converter circuit 1, a rectifier and filter circuit 2, an abnormality protection circuit 3, and a lighting circuit 14, all installed inside an explosion-proof housing 23.

[0034] The rectifier and filter circuit 2 is connected to the intrinsically safe power supply for mining. The rectifier and filter circuit 2 includes a three-phase rectifier bridge 4, a phase-shifting capacitor 5, a phase-shifting inductor 6, and a filter capacitor 7. The AC N-phase input terminal of the intrinsically safe power supply for mining is connected to one phase AC input terminal of the three-phase rectifier bridge 4. The AC L-phase input terminal of the intrinsically safe power supply for mining is divided into two paths. One path is connected in series with the phase-shifting capacitor 5 and then connected to the other phase AC input terminal of the three-phase rectifier bridge 4. The other path is connected in series with the phase-shifting inductor 6 and then connected to the last phase AC input terminal of the three-phase rectifier bridge 4.

[0035] The DC output terminal of the three-phase rectifier bridge 4 is connected in parallel with the filter capacitor 7 and then connected to the DC input terminal of the DC-DC step-down converter circuit 1. The filter capacitor 7 is a thin film capacitor.

[0036] The abnormal protection circuit 3 includes a low-temperature combustible gas sensor 8, a fast thyristor 9, a coupling transformer 10, a current-limiting inductor 11, a freewheeling diode 12, and a varistor 13. The positive and negative terminals of the fast thyristor 9 are connected in parallel with the positive and negative terminals of the DC output of the DC-DC step-down converter circuit 1, respectively. The low-temperature combustible gas sensor 8 is connected in series between the positive terminal of the DC output of the DC-DC step-down converter circuit 1 and the gate of the fast thyristor 9. The coupling transformer 10 has a single-winding three-tap structure. The first and second taps are connected in parallel with the positive and negative terminals of the fast thyristor 9, respectively. The third tap is connected in series with the varistor 13 and then connected to the gate of the fast thyristor 9. The current-limiting inductor 11 is connected in parallel with the freewheeling diode 12 and then connected in series with the DC output of the DC-DC step-down converter circuit 1. Unequal air gaps are provided between the iron cores of the current-limiting inductor 11.

[0037] The lighting circuit 14 includes a lighting IoT module 15, a constant current diode 16, LED light groups 17, warning LED light groups 18, alarm LED light groups 19, a control transistor 20, and a control transistor 21. The positive and negative terminals of the power supply of the lighting circuit 14 are connected to the positive and negative terminals of the DC output of the DC-DC step-down converter circuit 1, respectively. The positive terminal of the power supply of the lighting circuit 14, after being connected in series with the constant current diode 16 and the lighting LED light groups 17, is connected to the negative terminal of the DC-DC step-down converter circuit 1. The IoT module 15... The positive and negative terminals of the power supply are connected to the positive and negative terminals of the power supply of the lighting circuit 14, respectively. The I / O output terminals of the IoT module 15 are connected to the bases of the control transistors 21 and 20, respectively. The negative terminals of the control transistors 21 and 20 are connected to the negative terminal of the power supply of the lighting circuit 14. The collectors of the control transistors 21 and 20 are connected in series with the warning LED group 18 and the alarm LED group 19, respectively, and then connected to the positive terminal of the power supply of the lighting circuit 14. The lighting circuit 14 also includes an antenna 22, such as... Figure 2 As shown, antenna 22 has a ring-shaped multi-turn structure, which is arranged around the inner wall of the explosion-proof housing 23. Both ends of antenna 22 are connected to the AC side of the multi-voltage rectifier circuit 25. The DC side of the multi-voltage rectifier circuit 25 is connected to the positive and negative terminals of the DC output terminal of the DC-DC step-down converter circuit 1. The transmitting antenna lead of IoT module 15 is connected to one end of antenna 22. The explosion-proof housing 23 is filled with a mixed liquid, which accounts for 90% of the volume of the cavity inside the explosion-proof housing 23. The mixed liquid is composed of carbon tetrachloride liquid, iron oxide particles, elemental iron powder, thickener, and suspending agent in the following mass percentages: carbon tetrachloride liquid 20-25%, iron oxide particles 35-40%, elemental iron powder 40-45%, thickener 3-4%, and suspending agent 5-7%. The size of iron oxide particles and elemental iron powder is 8000-10000 mesh.

[0038] The specific models of the above electronic components are not specifically specified; any commercially available ordinary products can be selected, as long as they can meet the usage requirements of this invention.

[0039] The above-described specific embodiments further illustrate the objects, technical solutions, and advantages of the present application. It should be understood that the above-described specific embodiments are merely illustrative of the present application and do not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A mine intrinsically safe luminaire, characterized in that, include: The rectifier and filter circuit (2) connected to the intrinsically safe power supply for mining includes a three-phase rectifier bridge (4), a phase-shifting capacitor (5), a phase-shifting inductor (6), and a filter capacitor (7). The AC N-phase input terminal of the intrinsically safe power supply for mining is connected to one phase AC input terminal of the three-phase rectifier bridge (4). The AC L-phase input terminal of the intrinsically safe power supply for mining is divided into two paths. One path is connected in series with the phase-shifting capacitor (5) and then connected to the other phase AC input terminal of the three-phase rectifier bridge (4). The other path is connected in series with the phase-shifting inductor (6) and then connected to the last phase AC input terminal of the three-phase rectifier bridge (4). In the DC-DC step-down converter circuit (1), the DC output terminal of the three-phase rectifier bridge (4) is connected in parallel with the filter capacitor (7) and then connected to the DC input terminal of the DC-DC step-down converter circuit (1). The abnormal protection circuit (3) includes a low-temperature combustible gas sensor (8), a fast thyristor (9), a coupling transformer (10), a current-limiting inductor (11), a freewheeling diode (12), and a varistor (13). The positive and negative terminals of the fast thyristor (9) are connected in parallel with the positive and negative terminals of the DC-DC step-down converter circuit (1), respectively. The low-temperature combustible gas sensor (8) is connected in series between the positive terminal of the DC-DC step-down converter circuit (1) and the gate of the fast thyristor (9). The coupling transformer (10) is a single-winding three-tap structure. The first and second taps are connected in parallel with the positive and negative terminals of the fast thyristor (9), respectively. The third tap is connected in series with the varistor (13) and then connected to the gate of the fast thyristor (9). The current-limiting inductor (11) and the freewheeling diode (12) are connected in parallel and then connected in series with the DC output terminal of the DC-DC step-down converter circuit (1). The lighting circuit (14) is connected to the DC-DC step-down converter circuit (1). The lighting circuit (14) includes a lighting IoT module (15), a constant current diode (16), an LED light group (17), a warning LED light group (18), an alarm LED light group (19), a control transistor (20), and a control transistor (21). The positive and negative terminals of the power supply of the lighting circuit (14) are respectively connected to the positive and negative terminals of the DC output of the DC-DC step-down converter circuit (1). The positive terminal of the power supply of the lighting circuit (14) is connected in series with the constant current diode (16) and the lighting LED light group (17) and then connected to the DC-DC step-down converter circuit (1). The negative terminal of the DC step-down converter circuit (1) is connected to the positive and negative terminals of the power supply of the IoT module (15) and the power supply of the lighting circuit (14), respectively. The I / O output terminal of the IoT module (15) is connected to the base of the control transistor (21) and the control transistor (20), respectively. The negative terminals of the control transistor (21) and the control transistor (20) are connected to the negative terminal of the power supply of the lighting circuit (14), respectively. The collectors of the control transistor (21) and the control transistor (20) are connected in series with the warning LED light group (18) and the alarm LED light group (19) and then connected to the positive terminal of the power supply of the lighting circuit (14).

2. A mine-used intrinsically safe luminaire according to claim 1, characterized in that, The DC-DC step-down converter circuit (1), rectifier filter circuit (2), abnormal protection circuit (3), and lighting circuit (14) are all installed inside the explosion-proof housing (23).

3. A mine-used intrinsically safe luminaire according to claim 2, characterized in that, The lighting circuit (14) also includes an antenna (22), which is a ring-shaped multi-turn structure and is arranged around the inner wall of the explosion-proof housing (23). Both ends of the antenna (22) are connected to the AC side of a multi-voltage rectifier circuit (25). The DC side of the multi-voltage rectifier circuit (25) is connected to the positive and negative terminals of the DC-DC step-down converter circuit (1). The transmitting antenna lead of the Internet of Things module (15) is connected to one end of the antenna (22).

4. A mine-used intrinsically safe luminaire according to claim 3, characterized in that, The explosion-proof housing (23) is filled with a mixed liquid. The volume of the mixed liquid accounts for 90% of the volume of the cavity inside the explosion-proof housing (23). The mixed liquid is composed of carbon tetrachloride liquid, iron oxide particles, elemental iron powder, thickener, and suspending agent in the following mass percentages: carbon tetrachloride liquid 20-25%, iron oxide particles 35-40%, elemental iron powder 40-45%, thickener 3-4%, and suspending agent 5-7%.

5. A mine-used intrinsically safe luminaire according to claim 4, characterized in that, The size of the iron oxide particles and elemental iron powder particles is 8000-10000 mesh.

6. A mine-used intrinsically safe luminaire according to claim 1, characterized in that, The current-limiting inductor (11) has unequal air gaps between its iron cores.

7. A mining intrinsically safe lighting fixture as described in claim 1, characterized in that, The filter capacitor (7) is a thin-film capacitor.

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