SU1486707A1 - Device for protecting compressor group from surging - Google Patents

Description

The invention allows to increase the reliability of protection. The device comprises a gas pressure sensor 1 at the compressor inlet 2, a gas pressure sensor 3 at the compressor outlet, a surge sensor 4 connected in series, a threshold

unit 5 and actuator 6 of individual bypass valve 7, control unit 8, first and second elements AND, timer, first relay repeater, OR connected in series, trigger, third AND, second relay repeater and actuator of the common bypass compressor 18 for the compressor group and for each compressor, the flow sensor 19 and anti-surge controller 20. The controller 20 includes a first adder, a second adder connected in series, a division unit, a third adder, a multiplication unit and a comparison unit. In the event of oscillations in one of the compressors at the output of the sensor 4 surge oscillations, in which quality m. B. a pressure sensor is used, a surge signal is generated that triggers the triggering of the threshold unit 5, which sends a signal to the actuator 6, completely opening the individual bypass valve 7. 3 Il.

(ABOUT

1486707

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1486707

The invention relates to the protection of compressors from surging.

The aim of the invention is to improve the reliability of protection.

FIG. 1 is a block diagram of the device; in fig. 2 is a block diagram of an anti-surge regulator; in fig. 3 - block circuit of the control unit.

The device (Fig. 1) contains a gas pressure sensor 1 at the compressor inlet 2, a gas pressure sensor 3 at the outlet of the compressor, a surge vibration sensor 4 connected in series, a threshold unit 5 and an actuator 6 of an individual bypass valve 7, as well as a control unit 8 ( Fig. 3), including the first element And 9, the second element And 10, timer 11, the first relay repeater 12, the series-connected element OR 13, the trigger 14, the third element And 15, the second relay repeater 16 and the actuator 17 common to the bypass valve group 18 and for each compressor - flow sensor 19 and anti-surge regulator 20 (FIG. 2), comprising a first adder 21 and a second adder 22 connected in series, a division unit 23, a third adder 24, a multiplication unit 25 and a comparison unit 26. In addition, the device contains a gas cooler 27 (FIG. 1) and limit switches 28 (FIG. 3).

The device works as follows.

The signals of sensors 1 and 3 (Fig. 1) of the gas pressure at the inlet and outlet of compressor 2, as well as the signal of the flow sensor 19, go to the inputs of the anti-surge regulator 20, respectively to the first adder 21 (Fig. 2), the second adder 22 and block 26 comparisons. The outputs of the first and second adders form signals proportional to P | + 1 and Ρ2 + Ι, where Р |, Рг - pressure of gas at the inlet and outlet of the compressor, respectively. From the outputs of the first and second adders, the signals arrive at block 23 of division, at the output of which a signal is generated, the proportional Р 2 1

now ρ- ^ ρ'ΐ ' ^P0C ' ^g Y ^{G1aYu11 |} .i on the third adder 24. At the output of the third adder 24, a signal is formed, proportional to "Р 2 4" 1 π p

now p ----— B, where B is a constant. With output +1

Yes, the third adder signal is fed to the multiplication unit 25, the output of which produces a signal proportional to

Ρ2 + Ι

A (p ----— B), where A is a constant.

Ρι + 1

From the output of the multiplication unit, the signal arrives at block 26, where it is compared with the signal ζ) of the gas flow sensor 19. The output signal сравнения of the comparison unit is formed according to the following rule:

P + 1

1, with ς <Α (ρΠ2-Β);

0, with ς)> Α (^ ρ — В) +6,

where δ is a constant characterizing the size of the return zone.

The output signal of the anti-surge controller comparison unit is supplied to one of the inputs of the OR element 13 (FIG. 3) of the control unit 8, and the other inputs of this element receive anti-surge regulators from other compressors. When a signal corresponding to a logical unit appears on one of the inputs of the OR element 13, a trigger 14 is triggered and a signal is generated at the output of the third element 15, causing the second relay repeater 16 to operate and the actuator 17 to move in the valve opening direction. After the valve is fully opened, one of the limit switches 28 is triggered, and the inverting input of the third element I 15 receives a signal that turns off the second relay repeater 16. When trigger 14 is triggered, timer 11 is triggered, which, after a predetermined time, generates a trigger enable signal 14 the input of the first element AND 9. If there is a permission signal in the absence of a signal at the output of the element OR 13 at the output of the first element AND 9, a return signal (reset) of the trigger 14 to its initial state is generated, the output of the trigger 14 generates a signal corresponding to a logical zero, which causes the output of the second element And 10 of the signal corresponding to the logical unit, causing the first relay repeater 12 to operate and move the actuator 17 towards the valve closing side. After the valve is completely closed, the signal that turns off the first relay repeater 12 comes to the inverse input of the second element 10. The first element 9 prevents the valve from closing if at least one of the signals from the anti-surge regulators is present at the inputs of the element OR 13.

When oscillations occur in one of the compressors at the output of the surge sensor 14, which can be used as a pressure sensor, a surge signal is generated, triggering the threshold unit 5, which sends a signal to the actuator 6, fully opening the individual bypass valve 7.

Claims (1)

Claim A device for protection against surge of a group of compressors equipped with common five 1486707 6 group bypass valve with limit switches and individual bypass valves containing gas pressure sensors at the inlet and outlet of the compressors and for each compressor - 5 surge surge sensor, threshold unit and actuator of individual bypass valve connected in series, characterized in that, in order to increase the reliability of protection, it additionally co-holds the control unit, including the first and second elements And, the timer and the first relay repeater, connected in series the OR element, the trigger, the third And element, the second relay repeater and the actuator of the bypass valve common to the group, and for each compressor - the flow sensor and anti-surge controller, including the first a mmator and a second adder connected in series, a division unit, a third adder, a multiplication unit and a comparison unit connected by a second input to a flow sensor, and an output to an OR element, with the inputs of the first AND element connected to the timer and the OR element, and the output to the installation the trigger input, the trigger output is connected to the timer and to the second element I, the input of the first relay repeater is connected to the second element I, and the output is connected to the actuator of the bypass valve common to the group, the limit switches are connected to the second inputs of the second and The third elements And, the first adder is connected to the second input of the division unit, and the inputs of the first and second adders are connected to gas pressure sensors at the inlet and outlet of the compressors. Rig.2 1486707 Fil. I r hnmomiodtniodi hpnandtnZe dg dokhoid ygodohnd u