Secondary pressure control mechanism and control method

Abstract

To effectively prevent poor control of secondary pressure while maintaining a relatively simple configuration and simple control.SOLUTION: A secondary pressure control mechanism includes a bypass path La that bypasses a pressure regulator 60 in a gas flow path L0, a bypass path opening / closing valve VD2 that switches the open / close state of the bypass path La, and a control device S that controls the open / close states of a pilot flow path opening / closing valve VD1 and the bypass path opening / closing valve VD2. After the control device S has put the pilot flow path opening / closing valve VD1 in a closed state and a valve body V1 of the pressure regulator 60 in a blocked state, it executes a pre-return bypass path opening control to put the bypass path opening / closing valve VD2 in an open state before putting the pilot flow path opening / closing valve VD1 in an open state and the valve body V1 of the pressure regulator 60 in an open state, and after executing the pre-return bypass path opening control, it executes a return opening / closing control to put the bypass path opening / closing valve VD2 in a blocked state and the pilot flow path opening / closing valve VD1 in an open state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a secondary pressure control mechanism including a pressure regulator that controls the opening degree of a valve element provided in a gas flow passage through which gas flows, thereby controlling a secondary pressure, which is the pressure on the secondary side of the valve element, to a set pressure, and a control method thereof. [Background technology]

[0002] Conventionally, a pressure regulator that controls the secondary pressure of gas flowing through a gas flow passage to a predetermined set pressure is known that includes a pilot passage and a pilot passage opening / closing valve that switches the open / closed state of the pilot passage (see Patent Document 1). In the pressure regulator disclosed in Patent Document 1, for example, in the event of an earthquake or the like, the pilot flow path opening / closing valve can be switched from an open state to a closed state to shut off the gas flow path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-053047 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the pressure regulator disclosed in the above Patent Document 1, for example, when restoring operation after an earthquake has subsided, the pilot flow path opening / closing valve is transitioned from a closed state to an open state in order to restore the shut-off pressure regulator and allow gas to flow through the gas flow path. However, if secondary pressure is introduced into the pressure detection section and the valve body of the control device opens suddenly, there is a risk of control failure such as overshooting when the secondary pressure reaches the set pressure. Therefore, it is possible to take control such as gradually opening the pilot flow path valve from a closed state to an open state. However, while there is an advantage in that the gradual introduction of secondary pressure to the pressure detection unit does not cause a sudden change in the pressure regulator, there is a disadvantage in that accurate secondary pressure cannot be transmitted in a timely manner, and depending on the pressure regulator, there are problems such as it not functioning properly, leaving room for improvement.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a secondary pressure control mechanism and a control method thereof that can effectively prevent poor control of the secondary pressure while maintaining a relatively simple configuration and simple control when opening the gas flow path after blocking the gas flow path by a pressure regulator. [Means for solving the problem]

[0006] The secondary pressure control mechanism for achieving the above object is as follows: a pressure regulator that controls the opening of a valve body provided in a gas flow passage through which gas flows, so that a secondary pressure, which is a pressure on the secondary side of the valve body, becomes a set pressure; and a pilot flow passage opening / closing valve for switching an open / closed state of the pilot flow passage of the pressure regulator. The secondary pressure control mechanism has the following characteristic configuration: a bypass passage in the gas flow passage that bypasses the pressure regulator, and a bypass passage opening / closing valve that switches between an open and closed state of the bypass passage; a control device for controlling an open / close state of the pilot flow passage opening / closing valve and the bypass flow passage opening / closing valve, The bypass passage has a flow path diameter smaller than a flow path diameter of the gas flow passage, The control device includes: a pre-restore bypass path open control for opening the bypass path open / close valve in an open state before the pilot flow path open / close valve is opened to set the valve element of the pressure regulator in an open state after the pilot flow path open / close valve is closed to set the valve element of the pressure regulator in a blocked state; After the pre-return bypass passage opening control is executed, a return opening / closing control for closing the bypass passage opening / closing valve and opening the pilot passage opening / closing valve is executed in the order described above.

[0007] A method for controlling the secondary pressure control mechanism to achieve the above object includes the steps of: a pressure regulator that controls the opening of a valve body provided in a gas flow passage through which gas flows, so that a secondary pressure, which is a pressure on the secondary side of the valve body, becomes a set pressure; and a pilot flow passage opening / closing valve for switching an open / closed state of the pilot flow passage of the pressure regulator. a bypass passage in the gas flow passage that bypasses the pressure regulator, and a bypass passage opening / closing valve that switches between an open and closed state of the bypass passage, In the secondary pressure control mechanism, a flow path diameter of the bypass passage is smaller than a flow path diameter of the gas flow passage, a pre-restore bypass path open control for opening the bypass path open / close valve in an open state before the pilot flow path open / close valve is opened to set the valve element of the pressure regulator in an open state after the pilot flow path open / close valve is closed to set the valve element of the pressure regulator in a blocked state; After the pre-return bypass passage opening control is executed, a return opening / closing control for closing the bypass passage opening / closing valve and opening the pilot passage opening / closing valve is executed in the order described above.

[0008] According to this configuration, the pre-restore bypass path open control closes the pilot flow path open-close valve and sets the valve body of the pressure regulator to a blocked state, and then opens the bypass path open-close valve before opening the pilot flow path open-close valve and setting the valve body of the pressure regulator to an open state. Therefore, the secondary pressure is increased in such a manner that gas is guided from the primary side to the secondary side of the gas flow path via the bypass path. As a result, there is no need to introduce the secondary pressure via the pilot flow path of the pressure regulator when the secondary pressure is increased, and there is no need for complex control such as gradually increasing the aperture of the pilot flow path open-close valve. Furthermore, in this configuration, after executing the pre-return bypass path open control, restoration opening / closing control is executed in which the bypass path opening / closing valve is closed and the pilot flow path opening / closing valve is opened. Therefore, for example, after the secondary pressure is raised to close to the set pressure, the pilot flow path opening / closing valve is opened, thereby controlling the opening of the valve body of the pressure regulator to a relatively small opening, or control is started from the closed state of the valve body of the pressure regulator which is both the target opening and the control opening, thereby effectively preventing overshooting of the secondary pressure. In addition, in this configuration, the flow path diameter of the bypass path is smaller than the flow path diameter of the gas flow path. Therefore, when the secondary pressure of the gas flow path is increased through the bypass path during the pre-return bypass path opening control, the gradient of the increase in pressure can be made relatively gradual. This makes it difficult for the secondary pressure to suddenly increase or for the secondary pressure to exceed the set pressure and overshoot, thereby suppressing the occurrence of control failures. From the above, it is possible to realize a secondary pressure control mechanism and a control method thereof that can effectively prevent poor control of the secondary pressure when the gas flow path is opened after being blocked by the pressure regulator, while maintaining a relatively simple configuration and simple control.

[0009] Further characteristic configurations of the secondary pressure control mechanism include: The open state of the bypass path opening / closing valve in the pre-restore bypass path opening control is a state in which the opening degree of the bypass path opening / closing valve is maintained at a predetermined opening degree.

[0010] According to this configuration, the open state of the bypass path opening / closing valve in the pre-return bypass path open control is a state in which the opening degree of the bypass path opening / closing valve is maintained at a predetermined opening degree, so that the bypass path opening / closing valve can be driven with simple control. Furthermore, in the pre-restore bypass passage opening control, the opening degree of the bypass passage opening / closing valve does not change, and the open state and the closed state do not switch, so that fluctuations in the secondary pressure due to poor valve control do not occur.

[0011] Further characteristic configurations of the secondary pressure control mechanism include: A pressure measuring unit that measures the secondary pressure is provided, The control device includes: When the pre-restoration bypass path opening control is being executed, When the difference between the maximum pressure and the minimum pressure measured by the pressure measuring unit during a predetermined measurement period becomes equal to or greater than a predetermined pressure difference judgment threshold, a temporary closure control is executed to temporarily close the bypass path opening / closing valve.

[0012] In a gas passage through which gas flows, air column vibrations that vibrate the gas inside the passage may occur. According to this configuration, when the pre-return bypass path opening control is being executed, if the difference between the maximum pressure and the minimum pressure measured by the pressure measuring unit in a specified measurement period becomes equal to or greater than the pressure difference judgment threshold value due to the temporary closure control, the bypass path opening / closing valve is temporarily closed, so that the secondary pressure can be increased while appropriately suppressing air column vibration.

[0013] Further characteristic configurations of the secondary pressure control mechanism include: a monitoring server is provided which is connected to the control device via a telecommunication line; The control device executes the pre-restoration bypass path opening control and the restoration opening / closing control based on a control signal from the monitoring server.

[0014] According to this configuration, even in the event of an earthquake or the like, when the pilot flow path opening / closing valve has been closed and the valve body of the pressure regulator has been shut off, and it is difficult for personnel to head to the site where the secondary pressure control mechanism for which the pre-return bypass path opening control and the restoration opening / closing control are to be executed is located, the pre-return bypass path opening control and the restoration opening / closing control can be executed appropriately at the required timing by remote operation based on commands from the monitoring server, and the supply of gas to the secondary side can be resumed. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is an overall configuration diagram of a secondary pressure control mechanism according to the embodiment; [Diagram 2] FIG. 11 is a graph showing a change in secondary pressure over time when pressure regulation is performed by a secondary pressure control mechanism according to the embodiment. [Diagram 3] FIG. 11 is a graph showing a change in secondary pressure over time when pressure regulation is performed by a secondary pressure control mechanism according to another embodiment. [Figure 4] 4 is a control flow when pressure regulation is performed by a secondary pressure control mechanism according to the embodiment. [Diagram 5] 13 is a control flow when pressure regulation is performed by a secondary pressure control mechanism according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The secondary pressure control mechanism 100 and the control method thereof according to the embodiment relate to a mechanism that maintains a relatively simple configuration and provides simple control when opening the gas flow path after blocking the gas flow path by the pressure regulator, while still effectively preventing poor control of the secondary pressure.

[0017] The secondary pressure control mechanism 100 of the embodiment includes a pressure regulator 60 that controls the opening degree of a main valve body V1 (an example of a valve body) provided in a gas flow passage L0 through which a gas (e.g., city gas 13A) flows, and controls the secondary pressure, which is the pressure on the secondary side of the main valve body V1, to become a set pressure. As shown in FIG. 1, the pressure regulator 60 includes a main governor 10 that adjusts the secondary pressure P2 of the gas flow passage L0 to a set pressure, and a pilot governor 50 that introduces a driving pressure to the main governor 10. The main governor 10 includes a first diaphragm D1 provided along the diaphragm plate 14, and the internal space is divided into a first chamber H1 and a driving pressure chamber H2 by the first diaphragm D1. The main governor 10 includes a main valve element V1 that opens and closes a main opening K1 provided in the gas passage L0, and the main valve element V1 is connected to the first diaphragm D1 by the valve stem 16 and moves in conjunction with the first diaphragm D1 to be opened and closed. That is, in the pressure regulator 60 according to this embodiment, the secondary pressure is controlled by adjusting the opening degree of the main valve element V1 between a closed state in which the main valve element V1 is seated on the main opening K1 formed around the main opening K1 and an open state in which the main valve element V1 is separated from the main opening K1, with the bottom part of the main valve element V1, which is connected to the valve stem 16, facing the secondary side of the gas passage L0 through which the fluid flows. Further, a first spring G1 is disposed in the first chamber H1 to bias the first diaphragm D1 in the valve opening direction of the main valve body V1.

[0018] The pilot governor 50 includes a sub-diaphragm D0 provided along the diaphragm plate 34, and the internal space of the pilot governor 50 is divided into a fifth chamber H5 and a sixth chamber H6 (an example of a pressure detection section) by the sub-diaphragm D0. The sixth chamber H6 of the pilot governor 50 is connected to a secondary pressure introduction passage L2 (an example of a pilot passage) connected to the secondary side of the gas passage L0 (the downstream side of the main governor 10). The pilot governor 50 further includes a sub-valve element V0 that opens and closes a sub-opening K0 provided between a primary pressure introduction passage L4 connected to the primary side of the gas passage L0 (the upstream side of the main governor 10) and a driving pressure introduction passage L3 connected to the driving pressure chamber H2 of the main governor 10. The sub-valve element V0 is connected to the sub-diaphragm D0 by a connecting rod 36 and moves in conjunction with the sub-diaphragm D0 to be opened and closed. Further, a second spring G2 is disposed in the fifth chamber H5 to bias the sub-diaphragm D0 in the valve opening direction of the sub-valve body V0. A connection passage L5 is provided to connect the secondary pressure introduction passage L2 and the driving pressure introduction passage L3, and the connection passage L5 is provided with a throttle portion Si that throttles the passage diameter.

[0019] By adopting this configuration, when the secondary pressure P2 in the gas flow passage L0 falls below the set pressure, the pressure in the sixth chamber H6 of the pilot governor 50, which communicates with the secondary pressure inlet passage L2, falls, and the secondary diaphragm D0 is displaced toward the sixth chamber H6 due to the biasing force of the second spring G2. As a result, the sub-valve element V0 of the pilot governor 50 operates to open, and the primary pressure is introduced into the driving pressure chamber H2 of the main governor 10. As a result, the pressure in the driving pressure chamber H2 increases, and the first diaphragm D1 is urged toward the first chamber H1 by the pressure in the driving pressure chamber H2 against the urging force of the first spring G1, displacing the first diaphragm D1 toward the first chamber H1, causing the main valve element V1 of the main governor 10 to operate to open, increasing the secondary pressure P2 in the gas passage L0 and adjusting the secondary pressure P2 to the set pressure. On the other hand, when the secondary pressure P2 in the gas flow passage L0 rises above the set pressure, the pressure in the sixth chamber H6 of the pilot governor 50, which is connected to the secondary pressure inlet passage L2, rises, and the pressure in the sixth chamber H6 displaces the secondary diaphragm D0 toward the fifth chamber H5 against the biasing force of the second spring G2. As a result, the sub-valve element V0 of the pilot governor 50 operates to close, and the fluid in the driving pressure chamber H2 of the main governor 10 is discharged to the secondary side of the gas passage L0 via the driving pressure introduction passage L3, the connecting passage L5, and the secondary pressure introduction passage L2. As a result, the pressure in the driving pressure chamber H2 decreases, and the first diaphragm D1 is displaced toward the driving pressure chamber H2 by the biasing force of the first spring G1, causing the main valve element V1 of the main governor 10 to operate to close, reducing the secondary pressure P2 in the gas passage L0 and adjusting the secondary pressure P2 to the set pressure.

[0020] Now, the secondary pressure control mechanism 100 of this embodiment has, in particular, the following configuration in order to effectively prevent poor control of the secondary pressure when the gas flow path L0 is opened after being blocked due to an earthquake or the like, while maintaining a relatively simple configuration and simple control. The secondary pressure control mechanism 100 includes a secondary pressure introduction passage on-off valve VD1 (an example of a pilot passage on-off valve) that switches the open / close state of the secondary pressure introduction passage L2, a bypass passage La that bypasses the pressure regulator 60 in the gas flow passage L0, a bypass passage on-off valve VD2 that switches the open / close state of the bypass passage La, and a control device S that controls the open / close states of the secondary pressure introduction passage on-off valve VD1 and the bypass passage on-off valve VD2. Furthermore, a pressure gauge S1 (an example of a pressure measuring unit) that measures the secondary pressure is provided on the secondary side of the gas flow passage L0 (on the secondary side of the pressure regulator 60 and downstream of the secondary side end of the bypass passage La). Here, the secondary pressure introduction passage on-off valve VD1 and the bypass passage on-off valve VD2 are solenoid valves that can be controlled by the control device S to switch between an open state and a closed state. The first chamber H1 of the main governor 10 is provided with a second connection passage L6 that is connected to the secondary pressure introduction passage L2 on the upstream side (primary side) of the secondary pressure introduction passage on-off valve VD1.

[0021] Furthermore, the flow path diameter (inner diameter of the flow path) of the bypass path La is configured to be smaller than the flow path diameter of the gas flow path L0. In detail, the ratio of the flow path diameter of the gas flow path L0 to the flow path diameter of the bypass path La is 2 to 60 times, the flow path diameter of the gas flow path L0 is about 50 A to 600 A, and the flow path diameter of the bypass path La is about 10 A to 25 A. In this way, by making the flow path diameter of the bypass path La smaller than the flow path diameter of the gas flow path L0, the pressure increase gradient during the increase of the secondary pressure in the pre-restore bypass path opening control is made relatively gentle, and the occurrence of poor control of the secondary pressure can be effectively suppressed. Incidentally, the gas flow rate through the gas flow passage L0 is 1000m 3 / h or more 3000m 3 / h or less, and the gas flow rate through the bypass La is several m 3 / h or more tens of meters 3 / h or less.

[0022] Incidentally, the control device S in this embodiment is connected to a monitoring server C via a network N such as an electric communication line, and is configured to be able to control the opening and closing of the bypass path opening / closing valve VD2 based on a control signal from the monitoring server C. For example, if an earthquake with a seismic intensity (or maximum acceleration) equal to or greater than a predetermined level occurs in an area where the secondary pressure control mechanism 100 is installed and an area to which gas is supplied by the secondary pressure control mechanism 100, the monitoring server C transmits a control signal to close the secondary pressure introduction passage on-off valve VD1, and the control device S closes the secondary pressure introduction passage on-off valve VD1 based on the control signal. As a result, a relatively high-pressure fluid in the driving pressure introduction passage L3 flows into the sixth chamber H6 of the pilot governor 50 and the first chamber H1 of the main governor 10 via the throttle portion Si, the sub-valve body V0 of the pilot governor 50 is closed, and the first chamber H1 and the driving pressure chamber H2 of the main governor 10 become equal in pressure, the main valve body V1 of the main governor 10 is closed, and the gas flow passage L0 is shut off. As described above, when the gas flow path L0 is blocked and an earthquake or the like subsides and recovery processing is performed, if the bypass path on-off valve VD2 is opened from the closed state and the secondary pressure is increased by widening the opening of the main valve body V1 of the main governor 10, there is a risk that the secondary pressure will exceed the set pressure and overshoot because the gradient of the pressure increase is large.

[0023] Therefore, when performing recovery processing after closing the secondary pressure introduction passage on-off valve VD1 and shutting off the main valve body V1 of the main governor 10, the control device S executes, in the order described below, pre-return bypass passage open control for opening the bypass passage on-off valve VD2 before opening the secondary pressure introduction passage on-off valve VD1 and shutting off the main valve body V1 of the main governor 10, and recovery open-close control for closing the bypass passage on-off valve VD2 and opening the secondary pressure introduction passage on-off valve VD1 after executing the pre-return bypass passage open control.

[0024] As a result, as shown in Fig. 2, before the main valve element V1 of the main governor 10 opens (before time t2 in Fig. 2), pre-return bypass passage opening control (control executed in period T1 between time t1 and time t2) is executed, so that the secondary pressure increases at a relatively gradual increase gradient. Thereafter, for example, when the secondary pressure measured by the pressure gauge S1 increases to the set pressure (time t2 in Fig. 2), the return opening / closing control is executed, so that the bypass passage opening / closing valve VD2 is closed and the secondary pressure introduction passage opening / closing valve VD1 is opened, and the main valve element V1 of the main governor 10 is opened without being opened too much, so that an overshoot of the secondary pressure can be suitably avoided.

[0025] In addition, the control device S maintains the opening degree of the bypass path opening / closing valve VD2 at a predetermined opening degree in the open state of the bypass path opening / closing valve VD2 during the pre-restore bypass path opening control, thereby preventing pressure oscillations caused by opening and closing of the bypass path opening / closing valve VD2 when the secondary pressure is increased. Incidentally, when the bypass path opening / closing valve VD2 is in an open state in the pre-restore bypass path opening control, the increase gradient of the secondary pressure is 0.033 kPa / min or more and 2.000 kPa / min or less.

[0026] Next, a control method for the secondary pressure control mechanism 100 according to this embodiment will be described with reference to the control flow of FIG. When the control device S receives a control signal related to seismic shutdown from the monitoring server C (Yes in #01), it closes the secondary pressure introduction path on-off valve VD1 (#02). This closes the main valve body V1 of the main governor 10, and blocks the gas flow path L0. On the other hand, when the control device S does not receive a control signal related to seismic shutdown from the monitoring server C (Yes in #01), it executes the judgment of step #01 at predetermined time intervals. After step #02, if the control device S receives a command for recovery processing from the monitoring server C (Yes in #03), it executes pre-recovery bypass path opening control (#04); if there is no command for recovery processing (No in #03), it waits for a predetermined time and then executes the judgment of step #03. As a result, the secondary pressure gradually increases at a relatively low pressure increase gradient through the bypass passage La having a smaller flow path diameter than the gas flow passage L0. Thereafter, when the control device S determines that the secondary pressure measured by the pressure gauge S1 is equal to or higher than the set pressure (Yes in #05), it executes the recovery opening control (#06). In detail, the control device S closes the bypass path opening / closing valve VD2 and opens the secondary pressure introduction path opening / closing valve VD1, thereby opening the main valve body V1 of the main governor 10 without opening it too much, and terminates the recovery process of the pressure regulator 60. On the other hand, when the control device S determines that the secondary pressure measured by the pressure gauge S1 is lower than the set pressure (No in #05), it executes the determination in step #05 at predetermined time intervals.

[0027] [Another embodiment] (1) In the above embodiment, the secondary pressure introduction passage on-off valve VD1 is controlled to be closed by a remote control command from the monitoring server C communicably connected to the control device S via a network N such as an electric communication line. However, the present invention is not limited to this configuration, and the secondary pressure introduction passage on-off valve VD1 may be an earthquake-sensing cutoff valve that can close by itself when a seismic intensity of a predetermined level or higher is detected. In this case, the opening control of the secondary pressure introduction passage on-off valve VD1 is realized by the recovery opening / closing control from the control device S, as in the above embodiment. In this configuration, there is no need to provide a monitoring server C, and the secondary pressure control mechanism 100 can be configured as an independent control mechanism that is not connected to the network N.

[0028] (2) In the above embodiment, the bypass passage opening / closing valve VD2 is an electromagnetic valve that can be switched between an open state and a closed state. However, the bypass passage opening / closing valve VD2 may be a flow rate adjusting valve whose opening degree can be controlled by the control device S.

[0029] (3) In the above embodiment, the control device S executes the pre-restoration bypass path opening control and the restoration opening / closing control. However, the monitoring server C may also be configured to issue execution commands for the pre-recovery bypass path opening control and the recovery opening / closing control, and the control device S may be configured to execute the opening / closing control of the secondary pressure introduction path opening / closing valve VD1 and the bypass path opening / closing valve VD2 based on the execution commands.

[0030] (4) As shown in FIG. 3, when the control device S is executing the pre-restore bypass passage opening control, air column oscillations may occur in the secondary pressure on the secondary side of the gas flow passage L0. In order to suppress such air column vibration, the control device S can also execute control based on the control flow shown in Fig. 5 instead of the control flow according to the above embodiment (shown in Fig. 4). Incidentally, the control flow shown in Fig. 5 executes steps #04-1 and #04-2, and steps #05-1 and #05-2 in addition to the control flow shown in Fig. 4, so the following description will focus on this control. As shown in the control flow of FIG. 5, when the control device S executes the pre-recovery bypass opening control of step #04 (control executed during the period T1a in FIG. 3) after time t1, if the control device S determines that the difference between the maximum pressure Pmax and the minimum pressure Pmin measured by the pressure gauge S1 is equal to or greater than the predetermined pressure difference determination threshold value ΔP during a predetermined measurement period (T2 in FIG. 3) (Yes in #04-1), it executes temporary closure control to temporarily close the bypass opening / closing valve VD2 (#04-2). After executing the temporary closure control, it waits for a predetermined time and then returns to the state before step #04-1. On the other hand, if the control device S determines that the difference between the maximum pressure Pmax and the minimum pressure Pmin is less than the pressure difference determination threshold value ΔP during the predetermined measurement period (T2 in FIG. 3) (No in #04-1), it proceeds to the determination of step #05. When the control device S determines that the secondary pressure measured by the pressure gauge S1 is equal to or higher than the set pressure (Yes in #05), it executes the recovery opening control (#06). On the other hand, if the control device S determines that the secondary pressure measured by the pressure gauge S1 is less than the set pressure (No in #05) and the bypass path opening / closing valve VD2 is in the open state (Yes in #05-1), the process returns to before step #04-1, and if the bypass path opening / closing valve VD2 is not in the open state (if it is in the closed state) (No in #05-1), the control device S sets the bypass path opening / closing valve VD2 to the open state (#05-2) and returns to before step #04-1.

[0031] In the above embodiment, a configuration including the secondary pressure introduction passage opening / closing valve VD1 that opens and closes the secondary pressure introduction passage L2 has been shown as an example of a pilot passage opening / closing valve. However, the present invention is not limited to this configuration, and a primary pressure introduction passage opening / closing valve (not shown) that opens and closes the primary pressure introduction passage L4, which is the pilot passage, may be provided as the pilot passage opening / closing valve instead of the secondary pressure introduction passage opening / closing valve VD1.

[0032] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided that no contradiction arises. Furthermore, the embodiments disclosed in this specification are merely examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0033] The secondary pressure control mechanism and control method of the present invention can be effectively used as a secondary pressure control mechanism and control method that can effectively prevent poor control of the secondary pressure while maintaining a relatively simple configuration and simple control when opening the gas flow path after blocking the gas flow path by the pressure regulator. [Explanation of symbols]

[0034] 60:Voltage regulator 100: Secondary pressure control mechanism C: Monitoring server L0: Gas flow path L2: Secondary pressure introduction passage (pilot passage) La: Bypass road N: Network P2: Secondary pressure Pmax: Maximum pressure Pmin: Minimum pressure S: Control device S1: Pressure gauge Si: Constriction section V1: Main valve body VD1: Secondary pressure introduction passage opening / closing valve (pilot passage opening / closing valve) VD2: Bypass passage opening / closing valve ΔP: Pressure difference judgment threshold

Claims

1. a pressure regulator that controls the opening of a valve body provided in a gas flow passage through which gas flows, so that a secondary pressure, which is a pressure on the secondary side of the valve body, becomes a set pressure; a pilot flow passage opening / closing valve that switches an open / closed state of a pilot flow passage of the pressure regulator, a bypass passage in the gas flow passage that bypasses the pressure regulator, and a bypass passage opening / closing valve that switches between an open and closed state of the bypass passage; a control device for controlling an open / close state of the pilot flow passage opening / closing valve and the bypass flow passage opening / closing valve, The bypass passage has a flow path diameter smaller than a flow path diameter of the gas flow passage, The control device includes: a pre-restore bypass path open control for opening the bypass path open / close valve in an open state before the pilot flow path open / close valve is opened to set the valve element of the pressure regulator in an open state after the pilot flow path open / close valve is closed to set the valve element of the pressure regulator in a blocked state; a secondary pressure control mechanism that executes, in the order described below, a pre-return bypass path open control, and then a return open / close control that closes the bypass path open / close valve and opens the pilot flow path open / close valve.

2. 2. The secondary pressure control mechanism according to claim 1, wherein the open state of the bypass passage opening / closing valve in the pre-restore bypass passage opening control is a state in which an opening degree of the bypass passage opening / closing valve is maintained at a predetermined opening degree.

3. A pressure measuring unit that measures the secondary pressure is provided, The control device includes: When the pre-restoration bypass path opening control is being executed, 3. The secondary pressure control mechanism according to claim 1, further comprising: a pressure measuring unit that measures a pressure difference between a maximum pressure and a minimum pressure and a pressure difference between the maximum pressure and the minimum pressure.

4. a monitoring server is provided which is connected to the control device via a telecommunication line; 3. The secondary pressure control mechanism according to claim 1, wherein the control device executes the pre-restoration bypass path opening control and the restoration opening / closing control based on a control signal from the monitoring server.

5. A method for controlling a pressure regulator, which controls an opening degree of a valve body provided in a gas flow passage through which a gas flows, and controls a secondary pressure, which is a pressure on the secondary side of the valve body, to a set pressure, comprising: a pilot flow passage opening / closing valve that switches an open / closed state of a pilot flow passage of the pressure regulator; a bypass passage in the gas flow passage that bypasses the pressure regulator, and a bypass passage opening / closing valve that switches between an open and closed state of the bypass passage, In the secondary pressure control mechanism, a flow path diameter of the bypass passage is smaller than a flow path diameter of the gas flow passage, a pre-restore bypass path open control for opening the bypass path open / close valve in an open state before the pilot flow path open / close valve is opened to set the valve element of the pressure regulator in an open state after the pilot flow path open / close valve is closed to set the valve element of the pressure regulator in a blocked state; a pre-return bypass passage opening control, and then a return opening / closing control for closing the bypass passage opening / closing valve and opening the pilot passage opening / closing valve, in the order described below.

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