SU1302025A1 - Method for protecting compressor from surging - Google Patents

Abstract

The invention relates to compressor building. The purpose of the invention is to increase the reliability of protection. The bypass through the gas bypass valve from the compressor outlet to the inlet of the latter is regulated. Depending on the position of the valve on the recirculation line, a signal is generated which is compared with the reference one. As the latter, the maximum of two theoretical values of the minimum allowable gas flow rate is chosen. Control is performed by the anti-surge controller. The sensor 9 measures the rotational speed of the compressor shaft. At the output of block 19, the signal is normalized in proportion to the square of the rotational speed. The set of static characteristics of the compressor, the frontier limit, are set. According to these characteristics, two theoretically possible values of the coordinates, more precisely the surge for a given mode of the compressor, determined by the speed of rotation of the shaft of the compressor, are determined. w (L 00 about to about N3 SL

Description

This invention relates to the protection of compressors against surging.

The purpose of the invention is to increase the reliability of protection.

The drawing shows a block diagram of a device implementing the proposed method.

A device for protecting compressor 1 from surging by regulating bypass through a bypass valve 2 of gas from the compressor output to the inlet of the latter includes a gas flow sensor 3 at the compressor inlet, a gas flow controller 4, a comparison unit 5, a bypass position sensor 6 valve, pressure regulator 7, unit 8, as well as sensor 9 of rotation of the compressor rotor, amplifier 10, dividing unit 11, functional converter 12-, first, second, third, quarter, fifth adders 13- 17, respectively, and the first. Second, third, h tvertsh. n - th and sixth blocks of multiplication 18 23, respectively.

The method is implemented as follows.

The signal n from the index of the rotational speed sensor 9 of the rotor of the compressor is fed to the inputs of the first 18 and second 19 multiplicators, the outputs of which form signals proportional to, respectively, and n, where dj is a coefficient. From the output of the second multiplication unit, the signal arrives at the input of the third multiplication unit 20, at the output of which a signal is formed proportional to d p, where d is a coefficient.

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In addition, a signal is formed at the output of the third adder 15, proportional to A d ha, where d and urn are coefficients.

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The signals from the outputs of the first and one-third of its adders are fed to the bristle multiplication unit 23, at the output of which a signal is generated, proportional to 4. The signal from the output of the second adder 14 is fed to the input of the fifth multiplication unit 22, the output of which produces a signal proportional to

c. The signals from the outputs of the 22 and sixth 23 multiplication blocks are fed to a quarter adder 16, the output of which produces a signal proportional to B - 4 ACs, which is fed to the input of the functional converter 12, which implements the square root function. The signals from the output of the functional converter 12 and from the output of the second adder 14 are fed to a five adder 17, the output of which forms a signal proportional to B - V / B 4 AC.

At the same time, from the output of the third adder 15, a signal proportional to A is fed to an amplifier 10, at the output of which a signal proportional to 2A is formed.

From the outputs of the sixth adder and the amplifier, signals are sent to the dividing unit 11, at the output of which a signal is formed, proportional to

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corresponding to the maximum value of the roots of the quadratic equation with coefficients depending on the speed of rotation of the compressor rotor. The specified equation corresponds to

The signals from the outputs of the first 18 and third 20 multiplicators and from the setter 8. arrive at the inputs of the first adder 13, at the output of which a representation of the surge boundary in the form of a signal is formed, a proportional parabola and compression characteristics with d + d p + d g- p, where the coefficient.

At the same time, the signal of sensor 9 is supplied to a quarter multiplication unit 21, JQ at the output of which is formed as a second-degree polynomial.

From the code of dividing unit 11, the signal arrives at block 5 of comparison.

The other input of the comparison unit 5 receives a signal from the output of the pressure regulator 7, which characterizes the position of the bypass valve by measuring the pressure of sensor 6 in the pneumatic actuator of the bypass valve 2 and comparing the pressure regulator 7 with the setpoint regulator signal 8 corresponding to the fully closed bypass valve the valve.

cash, proportional d - n, where d - coefficient.

The signals from the output of the fourth multiplier and from behind the sensor go to the second adder 14, the output of which produces a signal proportional to B d. + d. p, where d - coefficient.

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In addition, a signal is formed at the output of the third adder 15, proportional to A d ha, where d and urn are coefficients.

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The signals from the outputs of the first and third adders are fed to the bristle multiplication unit 23, at the output of which a signal is generated, proportional to 4. The signal from the output of the second adder 14 is fed to the input of the fifth multiplier 22, the output of which produces a signal proportional to

c. The signals from the outputs of the 22 and sixth 23 multiplication blocks are fed to a quarter adder 16, the output of which produces a signal proportional to B - 4 ACs, which is fed to the input of the functional converter 12, which implements the square root function. The signals from the output of the functional converter 12 and from the output of the second adder 14 are fed to a five adder 17, the output of which forms a signal proportional to B - V / B 4 AC.

At the same time, from the output of the third adder 15, a signal proportional to A is fed to an amplifier 10, at the output of which a signal proportional to 2A is formed.

From the outputs of the sixth adder and amplifier, the signals arrive at the dividing unit 11, at the output of which a signal is formed, proportional to

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corresponding to the maximum value of the roots of the quadratic equation with coefficients depending on the speed of rotation of the compressor rotor. The specified equation corresponds to

 representation of the parabolic surge boundary and compressor characteristics

 representation of the parabolic surge boundary and compressor characteristics

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ra as a polynomial of the second degree.

From the code of dividing unit 11, the signal arrives at block 5 of comparison.

The other input of the comparison unit 5 receives a signal from the output of the pressure regulator 7, which characterizes the position of the bypass valve by measuring the pressure of sensor 6 in the pneumatic actuator of the bypass valve 2 and comparing the pressure regulator 7 with the setpoint regulator signal 8 corresponding to the fully closed bypass valve the valve.

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The resultant signal (the maximum of which can be compared) from the output of the comparator unit is used as a reference reference signal and delivers the flow sensor 3 signal to the flow controller 4 to another input. At the output of the regulator 4, a control signal is generated, which is supplied to the pneumatic actuator of the bypass valve 2, sets the position of the bypass valve and the amount of gas bypass from the compressor outlet to its input, thereby preventing the occurrence of surging.

Claims (1)

Invention Formula The method of protection of the compressor from surge by regulating the bypass through the bypass valve of gas coming from the compressor output to the input post Editor A.Sabo Compiled by A. Barrshnikov Tehred L. Oleinik. Proofreader G. Reshetnik Order 1200/35 Circulation. 575Subscribe VNIVDI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 it, by measuring the flow rate of the gas entering the compressor, comparing the measured value with the value of the reference signal generated depending on the position of the bypass valve and supplying the control action to the bypass valve proportional to the difference of the compared values, characterized in that in order to increase reliability protection, additionally measure the rotational speed of the rotor of the compressor form a value proportional to the square of the rotational speed of the rotor of the compressor, determine the maximum value of the roots adratnogo equation with coefficients derived from the generated measured and zatsan- quantities, to and from the maximum knowledge cheniyu roots corrected value of the reference signal.