SU808701A1 - Method of protecting turbocompressor from surging - Google Patents

Description

one

The invention relates to a turbocharger and can be used for anti-surge control of compressor machines.

There is a method of protecting a turbocharger from surging by bypassing the working fluid according to a signal that characterizes the pre-surge state of the turbocharger and its subsequent termination 1.

However, the method does not reliably suppress a hard surge.

It is known from the theory of compressors and it is confirmed by practice that, with certain characteristics of a compressor, rigid excitation of oscillations having a hysteresis character can occur. These oscillations occur suddenly and may have a large amplitude, the magnitude of which, due to the sudden onset of oscillations, cannot be limited in time, which can lead to the destruction of the aggregate. The boundaries of the hard surge are determined by the hysteresis zone established experimentally during compressor tests. The prerequisite for reliably suppressing a hard surge is to move the operating point outside the hysteresis zone.

The known method provides reliable and effective suppression of hard surging, since the closing circuit of the actuator is closed by a time relay signal, i.e. without real, created by the time the position is closed

0 operating point of the compressor relative to the hysteresis hard surge zone.

The purpose of the invention is to increase reliability due to the effective suppression of hard surging.

The goal is achieved by the fact that they form an additional signal, which characterizes the moment when the operation of the turbocharger leaves the hysteresis surging zone, and the bypass is stopped according to the generated additional signal.

FIG. Figure 1 shows the structures5 on the system diagram for the implementation of the proposed method; in fig. 2 hysteresis surge zone; Fig, 3-meter device, made on hydraulic elements together with a tuner for zone his0

of the teresis in FIG. 4 .- curves obtained by testing the system.

Compressor 1, driven by rotation of drive 2, provides the consumer with blast supplied to discharge pipe 3. A measuring diaphragm is installed in suction pipe 4 (not shown

Measuring device 5 with the help of the forming part of the regulator b (with the pi-law of regulation or trace) or the block 7 adjusts the surging hysteresis zone with the executive body 8 of the system, Curves 9 and 10 (Fig. 2) are respectively const alignment lines regulation and protection rounds, and curve 11 - the line of closing the executive body. Hysteresis surge zone shaded.

Measuring device 12 (Fig. 3). is a two-pulse one, the sensitive element of which (mebrana 13) perceives pulses according to the discharge pressure of the compressor and the flow rate through it. The nozzle 14 of the measuring device 12 receives the water of the impulse line 15 formed by throttling the constant pressure water through the washer 16. The valve 17 can move relative to the nozzle 14, depending on the ratio of the measured parameters, and the water pressure in the pulse line unambiguously determines the position of the operating point of the compressor relative to the hysteresis surge zone.

In this scheme, an electric contact pressure gauge 18 installed in the pulse lasers, the lower contact of which is used to close the exhaust valve, serves as a setting unit for the hysteresis zone. FIG. Figure 4 shows oscillograms of continuous oscillations of flow rate (curve 19) when opening the exhaust valve (curve 20) by a certain amount.

Oscillogram 21 shows the damping of surge oscillations in the system implementing this method, if the final value of the opening of the exhaust valve (curve 22) is exactly the same as in the previous case, but the pre-operating point of the compressor is outside the hysteresis zone of the surging opening of the exhaust valve by the required value.

The method is carried out as follows.

When the compressor mode approaches the control loop setting line (curve 9 of Fig. 2), the damper 17 of the measuring device 5 approaches the nozzle 14, the pulse pressure increases and causes the opening of the actuator 8, limiting the growth of the network resistance. When surging, the electrical contact pressure gauge 18, when the operating point of curve 10 reaches ("Fig. 2), commands the full opening of the actuator 8. The operating point of the compressor shifts to the high flow zone and the electrical contact pressure gauge 18, the lower contact of which is set to the boundary of the hysteresis zone (. 11 of Fig. 2), when the operating point exceeds the limits of this zone, where the surge is no longer possible, gives a command to close the executive body 8, i.e. stop bypassing the working fluid.

Thus, this method is based on taking into account the real position of the operating point of the turbocharger relative to the hysteresis surge zone, which allows creating an anti-surge control system to ensure that the compressor leads out of the unstable zone.

The proposed method allows to increase the reliability of anti-surge control and, consequently, the entire unit.

The technical and economic efficiency of the method lies primarily in eliminating the costs associated with stopping the turbine unit due to the surging that has occurred.

Claims (1)

1. USSR author's certificate No. 410672, cl. F O) O 27/02, 1973. Pacvof Us HOiHtmoffVjt M9MnjHCCO) rO ffm ujHtpume / rtf ot / guOippfflf Ilt . (rheZ Ha ynpaS / ftHue ptey uf / ytouitf OptOfffOff 13 lpg 21 BUT Z2