SU1567807A1 - Method and apparatus for adjusting a gang of compressors connected to common injection manifold - Google Patents

Abstract

The invention relates to the regulation of compressors and makes it possible to increase the economy by eliminating gas overshoots with increasing gas pressure in the discharge manifold. The goal is achieved by acting on a common pressure regulator 17 on individual speed control loops, including a compressor rotor speed sensor 13, a second comparison unit 14, a speed regulator 15, and an actuator 16 connected to drive 3 of compressor 1. At the input of regulator 17 The difference between the signals of the gas pressure sensor 4 in the manifold of the discharge 2 and the minimum selector 18 is transmitted, which passes the smaller of the input signals proportional to the limiting and predetermined pressure of the gas in the discharge manifold, Recently, it is determined by multiplying the second unit 7 multiplies the compression ratio given the measured gas pressure sensor 9 at the compressor inlet. The maximum pressure of the gas in the injection manifold is determined in the first multiplication unit 8 by the gas pressure at the compressor inlet measured by the sensor 9 and the maximum compression ratio calculated in the first functional converter 20 by the total gas flow. A signal proportional to the total gas flow rate is generated in the adder 19 by the signals of the second functional transducers 21, which generate signals proportional to the flow rate of each compressor according to the signals of the setpoint 12 and the pressure sensors 9-11, temperature and pressure drop of the gas at the compressor inlet. 2 sec. f-ly, 1 ill.

Description

This invention relates to a compressor control technique.

The purpose of the invention is to increase efficiency by eliminating the bypass of gas with increasing gas pressure in the injection manifold.

The drawing shows the block diagram of the device that implements this method.

A device for controlling a group of compressors 1 connected to a common manifold 2 of injection and equipped with adjustable drives 3 of a compressor comprises a common gas pressure sensor 4 in a discharge manifold, a first comparison unit 5, a first multiplication unit 6, a second multiplication unit 7, and a first unit 8, for each compressor - pressure sensor 9, temperature sensor 10 and gas pressure differential sensor 11 at the compressor inlet, the second unit 12 and the compressor rotor speed sensor connected in series 13, the second comparison unit 14, the speed controller 15 and the actuator 16 associated with the compressor drive, as well as the general pressure controller 17, the minimum selector 18, the adder 19 and the first functional converter 20, and for each compressor the second functional converter 21.

The method is implemented in the device as follows.

For each compressor, the signals of the sensors 9, 10, 11 and the second unit 12 are fed to the second functional converter 21, the output of which produces a signal proportional to

, -, no.

0

with

0

five

where Q is the gas flow rate through the i-th compressor; P - gas pressure at the inlet

compressor; Tt - inlet gas temperature

compressor; i - pressure drop at the inlet

1st compressor; K - coefficient.

From the outputs of the second functional converters 21, the signals are fed to an adder 19, the output of which produces a signal proportional to the total flow rate Q and is fed to the first functional converter 20, the output of which produces a signal proportional to

Јpr AQ1 + BQ + C,

where Ј „p is the limiting value of the degree

squeeze; A, B, C - coefficients.

From the output of the first functional converter 20, the signal is fed to the first multiplication unit 6, to another input of which the signal of the gas pressure sensor 9 arrives at the compressor inlet. At the output of the first multiplying unit 6, a signal is generated that is proportional to the limiting pressure of the gas in the injection manifold pnp E-rtf Pi and is fed to the input of the minimum selector 18. The other input of the selector 18 receives a signal from the second multiplication unit 7, proportional to

where РЗ is the specified value of gas pressure in the injection manifold;

Ј3 - given degree of compression. The output of the selector 18 passes the smaller of the two input signals and is fed to the first comparison unit 5, the second input of which receives the signal of the gas pressure sensor 4 in the discharge manifold. The difference between the signal of the sensor 4 and the selector 18 from the output of the comparison unit 5 act. There is a pressure regulator 17 (e.g., type RBA-P, which forms the proportional-integral-differential control law). From the output of the regulator 17, the signal is fed to the inputs of the second comparison unit 14. To the other input of the second comparison unit 14, the signal of the rotation speed sensor 13 of each compressor is supplied. The difference signal from the output of the second comparator unit is fed to the speed controller 15, which, acting through the actuator 16 on the compressor drive 3, adjusts the rotational speed of each compressor.

Claims (2)

Invention Formula 1 o A method of controlling a group of compressors connected to a common injection manifold and equipped with actuators with individual rotor speed controllers, by measuring the gas pressure in the discharge manifold, measuring the pressure at the inlet to each compressor, measuring and comparing with the total setpoint rotor speed five 0 compressors and supply to individual controllers of the difference between the measured and total set values of the rotational speeds of the rotors of the compressors, from and to the fact that, in order to increase efficiency by eliminating the bypass gas with increasing gas pressure in the collector - g of injection, in addition to the measured values of pressure, temperature and gas pressure drop at the inlet to each compressor, the gas flow rate for each compressor and the total gas flow rate are determined, determined by the resulting total gas flow rate The limit value of the degree of compression, and the target and limit values of the gas pressure in the discharge manifold are determined, respectively, by the predetermined and maximum degree of compression and by the measured gas pressure at the compressor inlet, the minimum of the specified and limit pressure values is determined and compared with the measured the value of the gas pressure in the discharge manifold and, depending on the difference obtained, form the total setpoint value of the rotation speed of the rotors 0 compressors. 2. A device for regulating a group of compressors connected to a common discharge manifold and equipped with adjustable drives. a pressure device containing a common gas pressure sensor in the discharge manifold, the first comparison unit, the first and second multiplication units, and the first setpoint unit connected to the last one, and also for each compressor pressure sensors, temperature and pressure differential gas at the entrance to the compressor, the second unit and series-connected speed sensor 5 compressor rotors, a second comparison unit, a speed controller and an actuator associated with the compressor drive, characterized in that it additionally 0 contains a common pressure regulator, a minimum selector, an adder and a first functional converter, as well as for each compressor a second functional converter connected by inputs to the second setpoint and pressure sensors at the compressor inlet, the totalizer inputs being connected to Outputs Repeat Functional715678078 converters, the first function-to the minimum selector, the inputs of the first A real converter is connected to the comparison unit and connected to the sensor. the input to the adder, and the output to the gas pressure in the collector and to the selective first multiplication unit, the second to the minimum input, and the output to the control of the first and second blocks, multiply the pressure, and the second inputs of the second No podtyucheny to the pressure sensor g-blocks of the comparison are connected to the regulator at the entrance to the compressor, and the outputs to the pressure generator.