RU16739U1 - AUTOMATIC DRAINAGE INSTALLATION - Google Patents

Abstract

The utility model relates to the field of protection against corrosion by stray currents of oil and gas pipelines laid along a direct-current electrified railway, as well as metal sheaths of power supply cables, communications, alarm cables, centralization, blocking in railway transport.

The purpose of the utility model is to optimize the protection of underground structures by maintaining the protective potential of the structure within the limits established by GOST.In an automatic drainage installation containing a drainage circuit of a fuse, a knife switch, a shunt with a measuring device connected in series, a power switch, a reference electrode, and a control unit are introduced.

At the output of the control unit, pulses are formed, the duration of which is the shorter, the greater the potential of the building - the ground. The pulse train controls the operation of the power switch. During the duration of the pulse, the switch is in the on state, and stray currents are removed from the underground structure to the rails. During a pause, the switch is turned off, the circuit breaks.

Thus, the protective potential of the structure is maintained within specified limits.

ESSAY

Description

1 2 G b S. B

Kandaev Vasily Andreevich Sveshnikova Natalya Yuryevna

AUTOMATIC DRAINAGE

The utility model relates to the field of protection against corrosion by stray currents of oil and gas pipelines laid along an electrified railway, as well as metal rims of power supply cables, communications, alarm cables, centralization, blocking in railway transport.

Known reinforced drainage installation, which is a constant current source connected between the protected structure and the midpoint of the throttle transformer. In addition to the function of current drain in one direction, provided through the rectifier device, the protection effect is enhanced by the action of a constant current source. With small values of the drainage current, when the minimum protective potential of the structure is not provided, an additional source is included in the drainage circuit, which ensures that the potential of the building is maintained within the specified limits. (A.S. 842680 USSR, MKI C23F 13/00. Reinforced electric drainage device for protecting underground metal structures from corrosion caused by stray currents / Levin V.M., Tarnizhevsky M.V., Lomanovich V.A. et al. / / Discoveries. Inventions. 1963.).

The disadvantage of this installation is that with a significant potential difference between the structure and the rail, a potential is formed on the protected structure, the value of which is less than the minimum allowable.

The closest in technical essence to the proposed utility model is a polarized drainage installation consisting of a knife switch, a shunt, an ammeter, control resistors with jumpers, valves and a safety installation MKI C23F 13/00

the carrier. (Nikolsky KK Drainage protection of metal sheaths of communication cables from corrosion. - M.: Svyazizdat, 1961, 56 pp.)

The disadvantage of this drainage installation is the stepwise manual adjustment of the drained current, when during the adjustment of the protection, such resistance is established that provides the average drained current at the level required. Insofar as the potential difference between the structure and the rail is constantly changing, at certain points in time on the protected structure there may be potentials of smaller or larger values established by GOST. (GOST 9.602-89 Underground structures. General requirements for protection against corrosion. M: GKS, 1989, 54p.).

The purpose of the utility model is to optimize the protection of underground structures by maintaining the protective potential of the structure within the limits established by GOST. (GOST 9.602-89 Underground structures. General requirements for protection against corrosion. M: GKS, 1989, 54p.).

The goal is achieved by the fact that in an automatic drainage installation containing a drainage circuit of a fuse, a knife switch, a shunt connected to a measuring device connected in series, a power switch, a reference electrode, a control unit consisting of a reference voltage source, a clock pulse generator, sawtooth voltage shaper are introduced, an error signal amplifier, a comparator, a comparator, a counting trigger, a first and second match circuit, an OR circuit, and the power switch is turned on I am waiting for the rail and the protected structure through the drainage circuit, the reference electrode, the underground structure and the reference voltage source are connected to the first, second and third inputs of the comparing device, the output of the clock pulse generator is connected to the inputs of the sawtooth voltage generator and the counting trigger, the output of the comparing device is connected to the amplifier input error signal, the outputs of the error signal amplifier and the sawtooth voltage driver are connected to the first and second inputs of the comparator, respectively , The comparator output is connected to the first

the inputs of the first and second matching circuits, the non-inverting output of the counting trigger is connected to the second input of the first matching circuit, the inverting output of the counting trigger is connected to the second input of the second matching circuit, the outputs of the first and second matching circuits are connected to the first and second inputs of the OR circuit, respectively, the output of the OR circuit connected to the control input of the power switch.

In FIG. 1 shows a functional diagram of the proposed automatic drainage installation, in FIG. 2 - 9 waveforms at the outputs of the elements of the functional diagram.

The automatic drainage installation (Fig. 1) contains a fuse 1, a switch 2, a shunt 3 with a measuring device 4, a power switch 5, a comparison electrode 6, a control unit 7, consisting of and a comparator 8, a reference voltage source 9, a clock generator 10 , a sawtooth voltage shaper 11, an error signal amplifier 12, a comparator 13, a counting trigger 14, matching circuits 15 and 16, an OR circuit 17.

Installation works as follows.

The potential of the underground structure - the ground, defined relative to the reference electrode 6, is fed to the input of the comparator 8, where it is compared with the reference voltage of the source 9. From the output of the comparator 8, the error signal is fed to the error signal amplifier 12, from the output of which the analog voltage UO is applied to the input of the comparator 13. The sawtooth voltage Un (Fig. 3) is supplied to the second input of this comparator, which is generated in the sawtooth voltage shaper 11 and synchronized by the clock generator pulses 10 (figure 2). An error signal U01 corresponds to a pulse of duration tl, and a signal of U02 corresponds to a pulse of duration t2. The pulses of the clock generator (Fig. 2) are supplied to the counting trigger 14. At the non-inverting output of the trigger 14, rectangular pulses Utl having a duration T and a repetition period of 2T are obtained (Fig. 4). At the inverting output of the counting trigger 14 positive rectangular pulses Ut2

compared with Utl by half the period, i.e. on T (Fig. 5). At the output of the comparator 13, pulses with PWM are obtained, the duration of which is the shorter, the larger the error signal (Fig. 6). The pulse sequence Utl is supplied to the input of the matching circuit 15, and the sequence Ш2 to the input of the matching circuit 16. At the output of the matching circuits, we obtain pulses UB1, UB2 corresponding in duration to the overlapped part of the pulses of the sequences ui and Utl (UB1) and ui and Ut2 (UB2) (Fig. 7.8). Having added up the voltages from the outputs of matching circuits 14 and 15, at the output of the OR circuit 17, we obtain a pulse sequence with a period T and duty cycle varying from O and 1 (Fig. 9).

At the output of the control unit, pulses are formed, the duration of which is the shorter, the greater the potential of the building - the ground. The sequence of pulses controls the operation of the power switch 5. Thus, during the duration of the pulse, the switch is in the on state, and stray currents are diverted from the underground structure to the rails. During a pause, the switch is turned off, the circuit breaks.

Thus, the protective potential of the structure is maintained within specified limits.

Protection of the drainage device from overloads is carried out using a fuse 1, installed in the drainage circuit.

The value of the drained current is determined using a measuring device 4 with a shunt 3.

Nrorektorb2 ,. Cheremisin

Claims (1)

An automatic drainage installation containing a drainage circuit of a fuse, a circuit breaker, a shunt with a measuring device connected in series, characterized in that a power switch, a reference electrode, a control unit consisting of a reference voltage source, a clock pulse generator, a sawtooth shaper, an amplifier are inserted into it an error signal, a comparator, a comparator, a counting trigger, a first and second matching circuit, an OR circuit, the power switch being connected between the rail and the protected structure through the drainage circuit, the reference electrode, the underground structure and the reference voltage source are connected to the first, second and third inputs of the comparing device, the output of the clock generator is connected to the inputs of the sawtooth voltage generator and the counting trigger, the output of the comparing device is connected to the input of the error signal amplifier, the outputs of the error signal amplifier and the sawtooth voltage driver are connected to the first and second inputs of the comparator, respectively, the output of the compar Ora is connected to the first inputs of the first and second matching circuits, the non-inverting output of the counting trigger is connected to the second input of the first matching circuit, the inverting output of the counting trigger is connected to the second input of the second matching circuit, the outputs of the first and second matching circuits are connected to the first and second inputs of the OR circuit, respectively , the output of the OR circuit is connected to the control input of the power switch.