JPH0430397Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a variable stator vane control device for a turbo compressor, and in particular allows changes in control settings and functions without replacing various instruments, etc. This invention relates to a variable stator vane control device for a turbo compressor.

[Prior art] The conventional variable stator vane control device for a turbo compressor is
As shown in the figure, it is composed of various devices, meters, etc.

Specifically, during normal operation of a turbo compressor a driven by a drive machine m, the discharge pressure detected by a pressure detector b is sent to a pressure regulator (hereinafter referred to as "PIC") c as an electric signal. The PICc compares a preset set pressure with the input discharge pressure and inputs the difference as an electric signal to the opening adjustment means d. The opening adjusting means d includes a converter e that converts an electric signal of deviation into a hydraulic signal, and an actuator g that operates a variable stator vane f to adjust its opening according to the hydraulic signal from the converter e. The amount of actuation of this actuator g is detected and the converter e is
and an opening transmitter h that outputs a feedback signal. The opening adjusting means d adjusts the opening of the variable stator vane f by feedback control so that the discharge pressure becomes a set pressure. Furthermore, a minimum opening setting device i is interposed between the PICc and the opening adjusting means d, and limits the electrical signal from the PICc so that the opening of the variable stator vane f is not narrowed down too much. It's becoming like that.

On the other hand, when starting up the turbo compressor a,
First, the first switch (hereinafter referred to as "No.1SW") j is switched to the first signal generator (hereinafter referred to as "No.1SG") k side, and the forced signal from No.1SGk is switched to the first signal generator (hereinafter referred to as "No.1SG") k side. A fully closed signal is input to the opening adjustment means d, and the compressor a is started with the variable stator blade f in the fully closed state. After that, when the compressor a reaches the rated speed, an electric signal from the detector l detects this and No.1SWj
is switched to the minimum opening setting device i side. At this time, the second switch (hereinafter referred to as "No.2SW")
n is the second signal generator (hereinafter referred to as "No.2SG")
It is switched to the p side, and a forced predetermined opening signal from No. 2SGp is input to the opening adjustment means d. As a result, the variable stator blade f is instantaneously opened to a predetermined opening degree. After that, No.2SGp is manually adjusted.
The power is switched to the PICc side and the normal operation described above is entered.

Further, a meter relay q is provided in each part of the wiring of these various designers, etc., to detect a disconnection when it occurs.

[Problems to be solved by the invention] By the way, in the conventional variable stator vane control device of a turbo compressor, PICc, SGk,
p, SWj, n, minimum opening degree setting device i, etc., were configured as separate devices and instruments, making it difficult to install them on a control panel, etc., and also making the control panel large. Also, wiring between these components was difficult. In particular, each of these instruments is set with various values such as the set value of the discharge pressure given at the time of design, the predetermined opening degree of the variable stator vane f, and its opening/closing timing, but these values are different from the actual ones. When operation is inappropriate, it becomes necessary to replace the instruments themselves, and this is inconvenient considering the need to change the mounting location due to the different sizes of the instruments.

The present invention was created to solve the above-mentioned problems.

[Means for Solving the Problems] The present invention includes a pressure detector that detects the discharge pressure of a turbo compressor, and an opening adjustment that adjusts the opening of a variable stator vane based on the discharge pressure detected by the pressure detector. A speed detector for detecting the rated speed of the turbo compressor; a speed detector for detecting the rated speed of the turbo compressor; and a speed detector for detecting the rated speed of the turbo compressor; When the variable stator vane is fully closed, and the speed detector detects the rated speed, the variable stator vane is instantaneously opened to the specified opening degree and set according to the discharge pressure detected by the pressure detector during normal operation. outputting a control signal to the opening adjustment means to open and close the variable stator blade at an opening greater than the minimum opening
It is equipped with a programmable control means whose control signal can be freely adjusted.

[Function] Regarding the function of the present invention, it is a programmable control means that can freely adjust control signals for various instruments, etc., which correspond to conventional PIC, SG, SW, etc. that send and receive electrical control signals such as set values. By configuring this, the functions of PIC, SG, etc., which were previously independent, can be achieved with a single control means, making the control panel more compact and the installation work easier, as well as simplifying the control signals such as set values. It is designed so that it can be adjusted to

[Embodiment] A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, a discharge system 4 of a turbo compressor 3 is equipped with variable stator vanes 2 that are rotationally driven by a driving machine 1.
is provided with a pressure detector 5 for detecting discharge pressure. Further, the variable stator vane 2 is provided with an opening degree adjusting means 6 for adjusting its opening degree. The opening adjusting means 6 has the same configuration as the conventional one, and outputs a hydraulic signal so that the input electric control signal matches the actual opening signal of the variable stator blade 2 from the opening transmitter 7, which will be described later. A converter 8 that outputs an output, an actuator 9 that operates the variable stator vane 2 to adjust its opening according to the hydraulic signal from the converter 8, and an opening of the variable stator vane 2 that is operated by the actuator 9. and an opening transmitter 7 which detects the position and outputs a feedback signal to the converter 8.

Furthermore, the drive machine 1 is provided with a speed detector 10 for detecting that the turbo compressor 3 has reached its rated speed.

By the way, between the pressure detector 5 and the opening adjustment means 6, a variable stator blade is installed in the opening adjustment means 6 by appropriately processing the electric signal of the discharge pressure detected by the pressure detector 5. A control means 11 is provided which has a single configuration such as a programmable microcomputer that outputs two opening degree control signals and can freely adjust the control signals. Hereinafter, the functions of this control means 11 will be explained according to the flowchart shown in FIG.

In the figure, the area surrounded by the broken line is the flow part related to switching, and the area surrounded by the two-dot chain line is the entire flow part within the control means 11 based on switching.

First, when starting up the turbo compressor 3, as shown in the stage, a fully closed signal and an opening signal of a certain predetermined opening are sent from the two signal generators 12 and 13 corresponding to No. 1SG and No. 2SG, respectively. Generated, No.1SW, No.
These signals are input to switching circuits 14 and 15 corresponding to 2SW. At this time, priority is given to the fully closed signal, and as a result, the fully closed signal is input to the converter 8 of the opening adjustment means 6, and the variable stator blade 2 is completely closed.

If the variable stator vane 2 is fully closed at startup in this way,
Since the load can be reduced, it can be started with a small starting torque, and a drive machine 1 with a small capacity can be used, leading to cost reduction. In addition, power consumption can be reduced and energy savings can be achieved.

Thereafter, this state is maintained until the turbo compressor 3 reaches its rated speed.

Next, when it is detected by the electric signal from the speed detector 10 that the turbo compressor 3 has reached the rated speed, the control is switched and the control moves to the first stage.
In this stage, signal generator 1 corresponding to No.1SG
The signal from No. 2 is cut off, and the switching circuit 14 corresponding to No. 1 SW is switched to pass the signal as is, while the signal from the signal generator 13 corresponding to No. 2 SG is switched to the switching circuit 15 corresponding to No. 2 SW. Since the predetermined opening signal is input,
As a result, a predetermined opening signal is input to the converter 8 of the opening adjustment means 6, and the variable stator blade 2 is instantaneously opened to the predetermined opening.

In this way, it is possible to prevent the variable stator vanes 2, which have been in the fully closed state, from falling into a surging state. Here, the predetermined opening degree is a necessary opening degree set for each compressor in order to prevent such surging.

Next, after operating with the variable stator vanes 2 maintained at a predetermined opening degree, control is switched using the manual switch 16 or the like when transitioning to normal operation. When it is detected that a switching signal indicating a transition to normal operation has been input, switching is performed and control moves to the first stage. At this stage, the signal from the signal generator 13 corresponding to No. 2SG is also cut off, and the switching circuits 14 and 15 corresponding to No. 1 SW and No. 2 SW are both switched to allow the signal to pass through as is. As a result, a control signal is generated inside the control means 11 to open and close the variable stator vane 2 according to the discharge pressure detected by the pressure detector 5 and at an opening greater than or equal to the set minimum opening, thereby controlling the opening. It is output to means 6. Specifically, this control is performed by a regulator 17, which corresponds to a PIC, and a limiter 18, which corresponds to a minimum opening setting device. A required setting discharge pressure value is set in the regulator 17, and the actual discharge pressure is inputted from the pressure detector 5. And this regulator 17
outputs the deviation between the set pressure and the discharge pressure as an electrical signal. The output deviation is limiter 1
8 is input. The limiter 18 is designed to limit the input deviation value so that the variable stator blade 2 is not narrowed down excessively if the input deviation value is too large. A control signal output from the limiter 18 is input to the converter 8 of the opening adjustment means 6, and the variable stator vanes 2 are sequentially opened and closed so that the discharge pressure becomes the set pressure. In particular, when controlling during normal operation, limiter 1
Since the control signal is output via 8,
Surging can be prevented by restricting excessive narrowing of the variable stator blades 2.

This control means 11 also includes a disconnection circuit corresponding to a conventional meter relay, which determines whether or not a disconnection has occurred in the electrical signal transmission system within this means 11, and outputs a disconnection alarm signal when a disconnection occurs. An alarm 19 is provided.

The control means 11 has the functions described above. In particular, this control means 11 can freely change the set pressure in the regulator 17, the fully closed signal of the signal generators 12 and 13, the predetermined opening signal, the limit value of the limiter 18, etc. by a program. , it is now possible to freely output a desired control signal.

[Effects of the Invention] In summary, the present invention provides the following excellent effects.

Sending and receiving electrical control signals such as conventional set values
By configuring various instruments equivalent to PIC, SG, SW, etc. with programmable control means that can freely adjust control signals, PIC, SG, etc. were independent of each other.
These functions can be achieved by a single control means, making it possible to downsize the control panel and simplify the installation work, as well as to easily adjust control signals such as set values.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a preferred embodiment of the present invention;
FIG. 2 is a flowchart showing the control flow of the control means employed in the present invention, and FIG. 3 is a system diagram showing a conventional example. In the figure, 2 is a variable stator vane, 3 is a turbo compressor, 5 is a pressure detector, 6 is an opening adjustment means, and 11 is a control means.

Claims (1)

[Scope of utility model registration request] A variable stator vane control device for a turbo compressor, comprising a pressure detector that detects the discharge pressure of the turbo compressor, and an opening adjustment means that adjusts the opening of the variable stator vane based on the discharge pressure detected by the pressure detector. is provided between a speed detector for detecting the rated speed of the turbo compressor, the pressure detector and the opening adjustment means, and is configured to fully close the variable stator vane when the turbo compressor is started up. When the speed detector detects the rated speed, the variable stator vane is instantaneously opened to a predetermined opening, and the set minimum opening is set according to the discharge pressure detected by the pressure detector during normal operation. A turbo compressor characterized by outputting a control signal for opening and closing the variable stator blade at the above opening degree to the opening adjustment means, and a programmable control means that allows the control signal to be freely adjusted. Variable stator vane control device.