JPH026081B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention supplies fluid by keeping it constant using a pressure regulating valve, and opens a safety valve when the maintaining pressure of the pressure regulating valve becomes abnormally high. The present invention relates to a pressure control device that is capable of urgently shutting off a cutoff valve provided upstream of a pressure regulating valve when a situation occurs.

Such a pressure control device is necessary to supply fuel such as gas or liquid to a gas turbine, compressor, or the like. A typical prior art example is shown in FIG. A mechanical device 1 such as a gas turbine or a compressor is supplied with fluid, which is fuel, through fluid pipes 2, 3, and 4. A cutoff valve 5 is interposed between the fluid conduits 2 and 3. Air pressure is supplied to this shutoff valve 5 from a pilot line 8 from an air pressure source 6 via a three-way solenoid valve 7. By applying a control signal to the solenoid valve 7 from the line 9, the solenoid valve 7 supplies compressed air from the air pressure source 6 to the line 8, thereby opening the isolation valve 5. When the solenoid valve 7 closes, the cutoff valve 5 is cut off. On the downstream side of the cutoff valve 5, a pressure regulating valve 10 is interposed between the fluid conduits 3 and 4. The secondary pressure of this pressure regulating valve 10 is detected by a pressure transmitter 11 connected to the fluid pipe line 4. 2 from the pressure transmitter 11
Air pressure corresponding to the next pressure is given to the pressure regulator 13 from the pipe line 12. Pressure regulator 13 is line 1
Air pressure is applied via line 14 so that the opening degree of pressure regulating valve 10 is adjusted to a predetermined setting value Ps by the output from pressure transmitter 11 via line 14. The safety valve 15 is connected to the fluid conduit 4 further downstream than the pressure transmitter 11 . In this safety valve 15, the pressure in the pipe line 4 is lower than the pressure P0 of the fluid supplied to the cutoff valve 5 from the fluid pipe line 2,
and the value α is greater than the set value Ps of the pressure regulator 13.
When the pressure value reaches a higher value (=Ps+α), the valve becomes open, and then the pressure in the fluid pipe 4 reaches the value Ps+
The valve remains open even if it becomes less than α. The mechanical device 1 is connected to a fluid line 4, equivalently indicated by a constriction 16.

In such prior art, when the shutoff valve 5 is open, the pressure P0 of the fluid pipe line 2 and the fluid pipe line 3 are
is equal to the pressure P1, and the fluid pipe line 4 is maintained at the set value Ps by the action of the pressure regulating valve 10.
Safety valve 15 remains closed.

In the event of an emergency abnormality, the shutoff valve 5 is in a fully open state. As a result, fluid is not supplied from the fluid conduit 2 to the fluid conduit 3 side. At this time, pressure regulator 1
3 applies pressure from the pipe line 14 so that the pressure regulating valve 10 is fully opened. In this way, each pressure in the fluid pipes 3 and 4
P1 and P2 are zero.

Thereafter, when the shutoff valve 5 suddenly opens, the pressure P1 in the fluid line 3 instantly becomes equal to the pressure in the fluid line 2. At this time, due to the delay in the operation of the pressure regulator 13 and the pressure regulating valve 10, when the cutoff valve 5 is in emergency use, the pressures P1 and P2 in the fluid conduits 3 and 4 become approximately equal. Therefore, the pressure P2 in the fluid pipe line 4 exceeds the set value Ps of the pressure regulator 13, and further exceeds the value Ps+α at which the safety valve 15 is in the open state. Therefore, the safety valve 15 remains open.
Therefore, fluid cannot be supplied to the mechanical device 1 when the shutoff valve 5 is opened.

An object of the present invention is to provide a pressure control device in which secondary pressure is maintained constant by a pressure regulating valve via a shutoff valve, and a safety valve is opened when this secondary pressure becomes abnormally high. To provide a pressure control device which prevents the secondary pressure from becoming abnormally high and opening a safety valve when the safety valve is opened.

FIG. 2 is a system diagram of one embodiment of the present invention.
Corresponding parts of the prior art described in connection with FIG. 1 above are given the same reference numerals. A mechanical device 1 such as a gas turbine or a compressor is supplied with fluid such as fuel through fluid pipes 2, 3, and 4.
A shutoff valve 5 is interposed between the fluid conduits 2 and 3. This shutoff valve 5 is supplied with air pressure from a line 8 from an air pressure source 6 via a three-way solenoid valve 7. When the three-way solenoid valve 7 is energized by a control signal from the line 9, air pressure from the air pressure source 6 is supplied from the line 8 to the isolation valve 5, which opens the isolation valve 5.
When the three-way solenoid valve 7 is demagnetized, the line 8 becomes atmospheric pressure and the shutoff valve 5 is closed.

A pressure regulating valve 10 is interposed between the fluid conduits 3 and 4 on the downstream side of the cutoff valve 5 . Pressure control valve 10
A pressure regulating valve 10 is provided in the fluid pipe line 4 on the downstream side of the
A pressure transmitter 11 is connected to detect the secondary pressure. This pressure transmitter 11 outputs air pressure corresponding to the secondary pressure to a line 12. Pressure regulator 13
The opening degree of the pressure regulating valve 10 is determined by the output from the pressure transmitter 11 via the line 12, and the air pressure is derived to the pipe line 14 so that the pressure in the fluid pipe line 4 becomes a predetermined set value Ps, The air pressure in this pipe line 14 is
The pressure regulating valve 10 is thereby able to maintain the fluid line 4 at the set point Ps.

A safety valve 15 is connected to the fluid pipe line 4 on the downstream side of the pressure transmitter 11. The safety valve 15 is supplied with secondary pressure downstream of the pressure regulating valve 10 from the upstream side of the cutoff valve 5 via the fluid conduit 2 . The safety valve 15 has a pressure lower than the pressure P0 and the set value
The valve becomes open when the pressure value (=Ps + α) is higher than Ps by the value α, and once the valve is in the open state, even after the pressure P2 in the fluid pipe line 4 becomes less than the value Ps + α. Keep the valve open.

A position switching valve 17 is interposed between the conduit 14 and the pressure regulating valve 10 in a pilot operated spring offset type. Compressed air, which is a pilot fluid, is supplied to this switching valve 17 from a three-way solenoid valve 77 through a conduit 18. When no pilot pressure is applied to the line 18, the switching valve 17 is in the switching position 17a due to the force of the spring. When pilot pressure is applied to the line 18, the switching valve 17 is switched to the switching position 17b. At the switching position 17a, the pipe line 14
is shut off, and air pressure is applied to control the opening degree of the pressure regulating valve 10. The conduit 19 is open to the atmosphere, thereby blocking the pressure control valve 10. When the switching valve 17 is switched to the switching position 17b, the pipes 14 and 19 are connected and the pressure regulating valve 10 is switched to the switching position 17b.
The opening degree of is a value corresponding to the air pressure derived from the pressure regulator 13 to the line 14.

During operation, the three-way solenoid valve 7 is energized and the cutoff valve 5 is opened. At this time, the switching valve 17 is in the switching position 17.
Therefore, the pressure regulating valve 10 maintains the pressure P2 in the fluid pipe line 4 at the set value Ps by the action of the pressure regulator 13. Safety valve 15 remains closed.

In an emergency, the solenoid valve 7 is shut off, thereby closing the shutoff valve 5. The switching valve 17 sets the pipe line 19 to atmospheric pressure, thereby closing the pressure regulating valve 10. In this way, the supply of fluid to the mechanical device 11 is cut off.

In order to supply fluid to the mechanical device 1 again,
The three-way solenoid valve 7 is energized. As a result, the shutoff valve 5
is in an open state, and the pressure P1 in the fluid line 3 becomes equal to the pressure P0 in the fluid line 2. At this time, the switching valve 17 is in the switching position 17b. Therefore, the pressure control valve 10 starts a pressure control operation by the function of the pressure regulator 13 according to the output of the pressure transmitter 11. Therefore, the opening degree of the pressure regulating valve 10 gradually increases from the fully closed state, and the pressure P2 in the fluid pipe line 4 reaches the set value Ps. At this time, the overshoot phenomenon of the fluid pipe 4 exceeding the set value Ps is small, and therefore the safety valve 15 is prevented from being closed.

FIG. 3 is a system diagram of another embodiment of the present invention. This embodiment is similar to the embodiment shown in the second figure, and corresponding parts are provided with the same reference numerals. It should be noted that the switching valve 17 interposed between the pipes 14 and 19 is constituted by a spring offset type solenoid valve, and this solenoid valve 27 connects the three-way solenoid valve 7 from the line 9. Controlled by a controlling signal. A control signal from line 9 is applied to the three-way solenoid valve 7, and air pressure is applied to the shutoff valve 5 from the pneumatic pressure source 6 via line 8, so that when the shutoff valve 5 opens, the switching valve 27 switches. The position is switched to position 27b, and the conduits 14 and 19 are in a connected state. As a result, the opening degree of the pressure regulating valve 10, which had been in the closed state until then, is increased, and the pressure in the fluid pipe line 4 is controlled. Other configurations and operations are similar to those of the previous embodiment.

As described above, according to the present invention, when the cutoff valve is closed, the pressure regulating valve is also closed, and the cutoff valve 5 is closed.
Since pressure control of the pressure regulating valve is started when the pressure regulating valve opens, the secondary pressure of the pressure regulating valve is prevented from becoming abnormally high, thereby preventing the safety valve from opening.

[Brief explanation of drawings]

FIG. 1 is a system diagram of the prior art, FIG. 2 is a system diagram of one embodiment of the present invention, and FIG. 3 is a system diagram of another embodiment of the present invention. 1... Mechanical device, 2, 3, 4... Fluid pipe line, 5
...Shutoff valve, 10...Pressure control valve, 11...Pressure transmitter, 13...Pressure regulator, 15...Safety valve,
17, 27...Switching valve.

Claims (1)

[Scope of Claims] 1. A cutoff valve that is interposed in the middle of a fluid pipe line and opens and closes upon receiving a control signal; A pressure regulating valve that is arranged downstream of the cutoff valve in the fluid pipe line; a pressure transmitter that detects the secondary pressure of the pressure regulating valve; and a pressure regulating valve that adjusts the opening degree of the pressure regulating valve according to the output from the pressure transmitter so that the pressure becomes a predetermined set pressure. , connected to the downstream side of the pressure regulating valve of the fluid pipeline, where the pressure downstream of the pressure regulating valve is lower than the pressure of the fluid supplied from the upstream side of the cutoff valve, and higher than the set value. A safety valve that opens when the pressure reaches a certain value and maintains the open state, and a safety valve that receives the control signal given to the shutoff valve and keeps the pressure regulating valve closed when the shutoff valve is closed and shuts off the shutoff. A pressure control device comprising: control means for applying a signal from a pressure regulator to a pressure regulating valve when the valve is opened.