SU1670155A1 - Method of control of spark-safety of energy systems in explosive atmosphere - Google Patents

Abstract

The invention relates to the intrinsically safe power supply of energy-intensive systems designed for the safe transfer of electrical energy from a power source to a load on plants with an explosive atmosphere. The purpose of the invention is to increase the intrinsically safe power supply of energy-intensive systems. To do this, when an emergency discharge occurs, the circuit is energized with a discharge and then a closed circuit is formed with an emergency discharge. Inside the latter, the energy entering the discharge gap is limited to a safe value. Energy limitation is made by stabilizing the current. 1 il.

Description

The invention relates to the intrinsically safe supply of energy-intensive systems intended for the safe transmission of electrical energy from power sources to the load on enterprises with a dangerous atmosphere.

The aim of the invention is to increase the intrinsically safe power supply of energy-intensive systems.

The drawing shows a diagram of the device that implements the method.

At the moment of the energy isolation of the power source from the emergency-discharge circuit, a closed loop is created for the emergency portion of the circuit, the lifetime of which is several times less than the discharge duration, and the current. flowing in this circuit is not limited to a safe value, therefore overvoltages occur in the circuit, the absence of

limiting the energy released in the discharge gap, which may cause ignition of an explosive mixture

Therefore, in an emergency discharge circuit, it is necessary to limit the energy of the reactive load elements and the power source at the time of the start of the discharge, and the energy supplied from the reactive load elements is limited by current stabilization.

The device, which removes the method, contains the power source 1, the disconnecting switch 2, the first shunt switch 3 with short-circuit and over-voltage sensors, the second shunt key 4 with the start-of-discharge sensor, and the first shunt key 3 with short-circuit and over sensors the voltage is connected in parallel to the output of the power supply source 1, the second shunt switch 4 s

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A discharge sensor is connected in parallel to the output circuit, and a tripping key 2 is connected in series between the first 3 and second 4 shunt keys. The output circuit 5. a current limiter 6, a threshold element 7, for example a zener diode, with a current limiter 6 connected in series with it, are connected in parallel to the output circuit 5 and the load 8,

The device works as follows.

Under actual operating conditions, all elements and circuits of the device except the output circuit 5 and the load 8 either are not in an explosive atmosphere, for example, are installed on the surface of the mine, or, if they are in an explosive atmosphere, they are protected from their dangerous effects. for example, a flameproof enclosure. And only the output circuit 5 and the load 8 are directly in an explosive atmosphere, so that an emergency discharge arising in them with various damages can ignite the explosive mixture, which leads to an explosion.

In the absence of a fault in the output circuit 5, the tripping key 2 is open, the shunting keys 3 and 4 are locked, the current limiter 6 is disconnected from the output circuit 5 by the threshold element 7, and output voltage 1 is supplied to the load 8.

When an emergency discharge appears in the output circuit 5, which is in an explosive atmosphere, the sensor of the start of the discharge of the second shunt switch 4 is triggered and switches it on. This leads to an increase in the output current of the power source 1 in the circuit: source 1, disconnecting key 2. shunt key 4, overcurrent sensor of the first shunt key 3, source 1. Overcurrent sensor key 3, responding to overcurrent, turns on the first shunt key 3. which short-circuits the output of power source 1 and locks the shut-off key 2; Key 2 breaks the circuit of the emergency discharge circuit, preventing current flow in it, and also turns off the second shunt key

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4, When an accidental discharge occurs on the reactive elements of the output circuit of the output circuit 5, which are of an inductive nature, overvoltages occur due to the action of self-induced EMF. Under their influence, the threshold element 7 is triggered and a closed circuit of the output circuit 5 is created through the current limiter b and the threshold element 7, and the discharge gap also enters this circuit. The transient current flowing in this circuit is limited by the current limiter 6 to a safe value, not allowing the physical process occurring in the discharge gap to ignite an explosive mixture.

When an emergency increase in the output voltage or the output current of the power supply 1 is higher than the established allowable values, the first shunt switch 3 is activated by a signal from its over-voltage or over-current sensors, respectively. Then the process proceeds in the same way as in the previous case from the moment the key 3 was turned on.

The application of the method leads to the penetration of intrinsically safe power, transmitted to the load in the explosive atmosphere from the source through the communication line, which is achieved by forming a closed circuit of the output circuit of the source with an emergency discharge capable of igniting the explosive mixture. energy coming from the circuit n bit

Claims (1)

Claims of Invention A method of providing intrinsically safe energy systems to an explosive atmosphere, including limiting energy from reactive load elements and a power source at the time of the start of unloading, which is equivalent to that. that, in order to increase the intrinsically safe power supply of energy-intensive systems, the energy supplied from reactive load cells to the discharge is limited by current stabilization.