JPS63208697A - Turbo compressor control method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention controls the suction control valve in accordance with pressure changes in the discharge pipe system caused by fluctuations in the amount of air used. There is a need for information on control methods for turbo compressors.

[Prior art] The suction control valve of the turbo compressor is controlled in order to prevent lS/lI from overrotating the 1-drive motor of the turbo T:IL compressor due to changes in discharge pressure and to prevent leasing. Or, the discharge pipe system Shin J! [1 System 01) When controlling a valve, the J control method shown in FIG. 3 is usually adopted. In other words, the suction control valve CV installed in the suction pipe 2 of the turbo compressor 1 is controlled based on the pressure signal from the pressure detector 4 that detects the pressure in the discharge pipe 3.
Con 1~ by Shinni from the horned indication style III theory IPIC
In addition, the air discharge control valve C■2 is set so that it is rolled.
(Based on the signal from the differential pressure transmitter 5, the flow rate indication adjustment 11 is controlled by the signal from the FIC.

In the system shown in Figure 3, the point where the amount of air used decreases is shown in Figure 4.
2 if from point X to Risi territory V1. When entering B, in the stable operation region, the pressure is kept constant by throttling the suction control valve CV using pressure indication adjustment 1-IPIc.
At the 0 point, the pressure indicating controller PIC to the flow rate indicating controller 1-I
C, and the pressure relief 1 control valve Cv2 is opened by the signal from the differential pressure transmitter FT to prevent surging. S is the surge line, and ■ is the performance curve of 1).

As mentioned above, in the conventional method, pressure command adjustment;
Ic and flow rate indication adjustment 1-1-FIC are used to control the flow rate.Unless there is a difference between the sensitivities of the two, hunting will occur and good control cannot be achieved. The sensitivity of the indicating controller fIc was improved. Therefore, the pressure indication adjustment port PIC
When controlling the suction control valve CV to the 0 point before entering the surge region 8, use the pressure command adjustment 14.
Since the sensitivity of PI C is made dull, in the process of throttling the suction control valve CV by the pressure indicating regulator PIC, the sensitive flow rate indicating regulator FIC starts to move, and the suction control valve Cv1
The air will be blown to the back without narrowing down to -1 minute, and it will not be possible to bring the above 0 point to the position just before entering surge area B, and from a position far from the position where it enters surge area 1 and 8. J of energy loss due to air blowing
There were three of each. In addition, in the conventional system, the highly sensitive flow rate indicator regulator 1-IC and the insensitive pressure indicator regulator PIC are essential, and these two regulators, PIC and FIC, are indispensable. I needed to.

On the other hand, as a conventional method, there is an example in which the throttle of the suction control valve and the opening of the air discharge control valve are controlled only by the pressure horn indication adjustment 71prc without using a flow rate indication controller (IC). In this example, the output of pressure point instruction adjustment level P1 is 1.
Throttle the suction control valve from 00% to 70% and fix it there, 7
The purpose is to control the air discharge control valve so that it opens between 0% and ()%.

[Problems that the invention attempts to solve] Control [1-
In this case, the opening degree of the suction control valve is adjusted so that the output of the pressure command adjustment H1prc is 100% to 70%.
With this method, the switching timing of the suction control valve and the air discharge control valve will change depending on the change in suction temperature. VHewara, when the intake temperature of the turbo compressor is 30°C, it is possible to switch to air discharge at the 0 point as shown in Figure 5, but when the intake temperature of the turbo compressor is 10°C, Since the opening degree of the intake control valve is fixed, the performance curve becomes like a broken line, and the air is switched to air blowing at point C'.

Therefore, when the temperature becomes low, the air discharge control valve is opened even though the intake control valve can still be narrowed down, and air is discarded, resulting in a large energy loss.

The present invention brings the switching point when stopping the suction control valve 1 and listening to the air discharge control valve to a position on the edge of the surge line, and prevents ia from changing at that point.
This is a Togerushino that allows you to control from 1 to roll with only one force instruction adjustment n'l.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides pressure control to throttle the suction control valve based on a signal from a pressure detector that detects the pressure on the discharge side of the turbo compression valve. Instruction adjustment h
Connect the differential pressure transmitter and the air discharge control valve to ↑, and use the signal from the pressure detector to throttle the suction control valve.The signal from the differential pressure transmitter will detect a point close to the surge line. Then, the suction control valve is fixed by the control of the pressure point indication adjustment penalty, and the air discharge control valve is opened.
There is a method of rolling.

[Function] When the suction control valve is controlled and throttled by the pressure indication adjustment h1 based on the signal from the pressure detector, the performance curve of the turbo compressor shifts to the one-nerge region side. The point at the edge of the surge line is detected by the differential pressure transmitter, so when this point is reached, the signal from the differential pressure transmitter switches the pressure indication adjustment h1 to the control for opening the air discharge control valve. It will be done. This allows the surge line to be narrowed down to the very limit.

[Example] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Figure 1 shows a control system for implementing the present invention, in which a suction control valve CV is installed in the suction pipe 2 of the turbo compressor 1, and air is discharged into the branch pipe 6 connected to the H discharge pipe 3. In the configuration in which the control valve C2 is installed, the discharge piping 3 is provided with a pressure detector 4 that detects pressure and a differential pressure transmitter 5 that measures the flow rate based on the difference in pressure. It has the function of controlling the suction control valve CV by a signal, and also controls the suction control valve to be fixed and the air discharge control valve to be heard by the signal from the differential pressure transmitter 5. Adjustment 11PIc is used to switch from the suction control valve CVI to the discharge control valve Cv2 just before entering the surge region 8 with one pressure command adjustment PIC.

The discharge j1 force of the discharge piping 3 (3
(This pressure change is detected by the repulsive force detector 4, and the detection signal from the pressure detector 4 is transmitted to the pressure indication adjustment command PI.
C1,: Sent. Now, as the amount of air used decreases,
Pressure instruction adjustment δIPI to keep the discharge pressure constant
Control the intake control U++ valve CV to throttle it. In addition, the suction control rCv1 is narrowed down so that the performance curve 1 of the compressor in FIG. When it narrows down to 0 points, K
Since 0 point is detected from the flow ♡ measured by the 1-pressure light device 5, the repulsive force indication adjustment and H-IPIc are activated by the signal from this differential pressure transmitter 5, and the suction control valve CV is stopped. The air discharge control valve C2 is controlled to be pulled to a low level, and the operation is carried out at a constant pressure to avoid leasing.

[Effects of the Invention] As described above, according to the turbo compressor control method of the present invention, it is controlled with one pressure instruction adjustment unit, the suction control valve 11 is fixed just before entering the surge region, and the pressure is released [ The control valve is controlled so that it can operate at a constant pressure even if the amount of air used fluctuates, and the opening command for the air discharge control valve is based on the flow rate signal from the differential pressure transmitter. The control valve can be throttled down to the very edge of the surge line,
The problem of energy loss when switching to air blowing can be solved, and the flow indicator controller for air blowing control 1 and 7, which was required in the past, can be omitted and the pressure indicator adjustment r-1 can be eliminated.
There is no need to differentiate the sensitivity between the two, and since the suction control valve is not throttled depending on the suction temperature, there is no fear that the point at which the suction control valve is switched to the air discharge control valve will be inconsistent.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a relationship diagram between discharge pressure and air volume when controlled by the present invention, and FIG.
The figure shows an example of a conventional control system.
FIG. 5 is a diagram showing the relationship between the discharge pressure and the air volume when using the conventional Haku control method. 1...Turbo compressor, 2...Suction piping, 3...Discharge piping, 4...Repulsion force detector, 5...Differential pressure transmitter, P
IC...Pressure indication adjustment IT, CV+...Suction control valve, Cv2...Release T! I', the control valve.

Claims (1)

[Claims] 1) Connect a discharge pressure detector provided on the discharge side of the turbo compressor and a differential pressure transmitter that measures the flow rate based on the differential pressure to a pressure indicating controller, and connect the pressure indicating regulator to the compressor suction side. The suction control valve is connected to the suction control valve on the side and the air discharge control valve on the discharge side of the compressor, and the pressure indicating regulator is controlled to throttle the suction control valve, and the differential pressure transmitter is connected to the suction control valve at the position just before entering the surge region. A method for controlling a turbo compressor, characterized in that the point is detected by the signal, and the pressure indicating controller is controlled to stop the suction control valve and open the discharge control valve.