JP7300919B2 - Frequency response analysis method - Google Patents

Description

The present invention relates to a frequency response analysis method for a pilot governor used as a reverse acting pressure regulator.

Conventionally, a reverse acting pressure regulator and a pilot governor used therein are known as pressure regulators capable of controlling the displacement of the main valve body of the main governor when the secondary pressure rises or falls below the set pressure. (See Patent Document 1).
On the other hand, as one method of analyzing control systems, frequency response analysis is known, which examines control characteristics from responses to inputs such as sine waves. The frequency response analysis is often used in electrical and mechatronic systems, but it can of course also be applied to pressure regulators such as pilot governors, which are feedback control devices that do not require electricity. For example, in a pilot type governor, the input signal is the secondary pressure that is input to the pilot, and the output signal is the secondary pressure in the main valve downstream piping. As pressure, the stability of the system can be determined by performing a frequency response analysis for inputs at various frequencies.

JP 2017-182718 A

As described above, when conducting frequency response analysis of a pilot type governor or a pilot governor, it is necessary to apply a sine wave or the like, which is periodic vibration, to the secondary pressure detection chamber as an input signal. However, in a pilot type governor or a pilot governor used in a generally known reverse acting pressure regulating device as disclosed in Patent Document 1, the driving pressure discharged from the driving pressure chamber flows into the secondary pressure detection chamber. Therefore, an accurate sine wave cannot be given as an input signal. For example, by reducing the pipeline resistance of the secondary side pressure introducing path that is connected to the secondary pressure detection chamber, the driving pressure discharge resistance from the secondary side pressure introducing path can be reduced. However, in this method, it is not possible to apply a method of airtightly configuring the secondary pressure detection chamber and forcibly changing its volume to give a sine wave as pressure.

The present invention has been made in view of the above-mentioned problems, and its object is to be able to appropriately apply an actual pressure sine wave or the like as an input, to be able to measure the driving pressure as its output response, and to be able to control from these values. An object of the present invention is to provide a frequency response analysis method for a pilot governor of a reverse-acting pressure regulator that can perform frequency response analysis for analyzing characteristics.

The frequency response analysis method for achieving the above purpose is
A frequency response analysis method for a pilot governor used as a reverse-acting pressure regulating device, characterized by:
A first chamber partitioned by a housing and a first diaphragm and communicating with a secondary pressure introduction path, and an open hole partitioned by the housing, the first diaphragm and the second diaphragm and open to the outside. A second chamber formed in a housing, and a primary side pressure introduction passage partitioned by the housing, the second diaphragm, and the third diaphragm are connected in communication, and drive pressure is introduced into the drive pressure chamber of the main governor. a third chamber to which a drive pressure introduction passage is connected; a first biasing member that biases the third diaphragm toward the third chamber;
a connecting member that connects the first diaphragm, the second diaphragm, and the third diaphragm so that they have the same amount of displacement in a displacement direction;
In the displacement direction, the primary side pressure introduction end is opened and closed by being biased by the second biasing member from the side of the second diaphragm toward the primary side pressure introduction end, which is the introduction end of the primary side pressure introduction passage. an exhaust valve for adjusting an inflow amount of the primary pressure side fluid introduced from the primary side pressure introduction end to the third chamber;
an open valve that is connected to the exhaust valve and opens and closes an opening formed in the second diaphragm to adjust the amount of discharge released from the third chamber side to the second chamber side. A frequency response analysis method performed using a governor,
a pressure vibration imparting step of imparting periodic pressure vibration to the first chamber;
a pressure vibration measuring step of measuring the simulated secondary pressure accompanied by the periodic pressure vibration introduced into the first chamber;
a vibration measuring step of measuring vibrations at other sites caused by receiving the periodic pressure vibrations while the periodic pressure vibrations are being applied in the pressure vibration applying step;
Frequency at which frequency response analysis is performed based on the amplitude and phase of the simulated secondary pressure vibration measured in the pressure vibration measurement step and the amplitude and phase of the vibration at the other part measured in the vibration measurement step The point is to execute the response analysis process.

The three-diaphragm pilot governor having the characteristic configuration described above has a different configuration from the two-diaphragm pilot governor generally used as a conventional reverse acting pressure regulating device. When the secondary pressure rises, all the diaphragms descend and the drive pressure is discharged (in the case of a three-diaphragm configuration, it is discharged to the outside via the second chamber, and in the case of a two-diaphragm configuration, the secondary pressure When the secondary pressure drops, the drive pressure is supplied to the main governor, so basically it exhibits the same frequency response characteristics as a pilot governor with two diaphragms. it is conceivable that.
Furthermore, according to the pilot governor having the above characteristic configuration, the exhaust pressure released from the third chamber via the open valve is led to the second chamber and not led to the first chamber. A secondary pressure can be introduced as a periodic pressure oscillation as an input unperturbed by the discharge pressure.
Therefore, by using the pilot governor having the characteristic configuration described above, frequency response analysis is performed based on the periodic pressure vibration applied in the pressure vibration applying process and the driving pressure measured in the vibration measurement process. It is possible to obtain characteristics substantially equivalent to the frequency response characteristics of a pilot governor of a generally used reverse-acting pressure regulating device.
Therefore, the frequency response of the pilot governor of the reverse-acting pressure regulating device is capable of performing frequency response analysis that analyzes the control characteristics from these values, using the actual pressure sine wave, etc. as the input as well as the output as the driving pressure. Analysis method can be realized.

The pilot governor having the above characteristic configuration can be used for verification to know the frequency response characteristics of the conventional pilot governor as described above, and can also be put to practical use as a pilot governor for a reverse-acting pressure regulator. can also

A further characteristic configuration of the frequency response analysis method includes:
The step of applying pressure vibration is a step of applying the periodic pressure vibration to the first chamber at a plurality of different frequencies,
The pressure oscillation measuring step is a step of measuring the simulated secondary pressure generated at a plurality of different frequencies,
The vibration measurement step is a step of measuring the driving pressure generated for each of the periodic pressure vibrations generated at a plurality of different frequencies,
The frequency response analysis step includes
A gain derived from a ratio of the amplitude of the simulated secondary pressure vibration measured in the pressure vibration measurement step and the amplitude of the vibration in the other part measured in the vibration measurement step for each of a plurality of different frequencies. a gain output step of outputting for each of a plurality of frequencies;
The difference between the phase of the simulated secondary pressure vibration measured in the pressure vibration measuring step at each of a plurality of different frequencies and the phase of the vibration at the other part measured in the vibration measuring step at each of a plurality of frequencies a phase output step for outputting to
a stability determination step of determining stability of the pilot governor based on a Bode diagram created from the gain output output in the gain output step and the phase output output in the phase output step; at the point.

According to the determination, since the determination is based on the analysis based on the actual measurement, it is possible to make a determination that is more realistic than the method based on the numerical analysis that presupposes various assumptions.

4 is a schematic configuration diagram of a pilot governor used for frequency response analysis; FIG. FIG. 10 is an operation diagram when a pilot governor used for frequency response analysis operates; FIG. 4 is a graphical representation of the simulated secondary pressure with periodic pressure oscillations as input to the pilot governor, and a graphical representation of the drive pressure as output.

The frequency response analysis method of the pilot governor 100 according to the embodiment of the present invention can appropriately input an actual pressure sine wave or the like as an input and can measure the driving pressure as its output response, and analyze the control characteristics from those values. About what to do.

As shown in FIG. 1, the reverse-acting pressure regulating device 200 includes a reverse-acting main governor 10 that adjusts the secondary pressure of the fluid flow path L0 to a set pressure, and a pilot that introduces driving pressure to the main governor 10. A governor 100 is provided.

The main governor 10 has a main diaphragm D0 provided along the diaphragm plate 14, and the internal space thereof is divided into a fifth chamber H5 and a sixth chamber H6 by the main diaphragm D0. The main governor 10 includes a main valve body V0 that opens and closes a main opening K0 provided in the fluid flow path L0. It is configured to be opened and closed in a form that moves in conjunction with. A main biasing spring G0 that biases the main diaphragm D0 in the valve closing direction of the main valve body V0 is disposed in the fifth chamber H5.

The pilot governor 100 includes a first chamber H1 partitioned by the housing K and the first diaphragm D1 and connected to the secondary side pressure introduction path L2, and the housing K, the first diaphragm D1 and the second diaphragm D2. A second chamber H2 in which an open hole K1 that is partitioned and opened to the outside is formed in the housing K, and a primary side pressure introduction path L1 that is partitioned by the housing K, the second diaphragm D2, and the third diaphragm D3 are communicated. and a third chamber H3, to which a driving pressure introduction path L4 for introducing driving pressure into a sixth chamber H6 (an example of a driving pressure chamber) of the main governor 10 is communicated and connected; A connection that connects the first biasing member G1 that biases to the side, the first diaphragm D1, the second diaphragm D2, and the third diaphragm D3 so that they have the same amount of displacement in the displacement direction (direction of arrow Z in FIG. 1). In the displacement direction, the member R is biased by the second biasing member G2 from the second diaphragm D2 side toward the primary pressure introduction end L1a, which is the introduction end of the primary side pressure introduction path L1, so that the primary pressure introduction end L1a and an exhaust valve V1 that adjusts the inflow amount of the primary pressure side fluid introduced from the primary pressure introduction end L1a to the third chamber H3 by opening and closing the It also has an open valve V2 that opens and closes the opening DP2a to adjust the amount of discharge released from the third chamber H3 side to the second chamber H2 side.
Here, the drive pressure introduction path L4 is connected to the secondary side pressure introduction path L2 via a third fluid flow path L3 having a throttle 39 that narrows the flow path diameter. In addition, the end of the first biasing member G1 on the opposite side to the third diaphragm D3 is attached to a receptacle G2a provided so as to be screwed into a female threaded portion G2b provided on the inner peripheral surface of the housing K. The tray G2a is configured to be freely movable in the displacement direction (the arrow Z direction in FIG. 1) by rotating while being screwed into the female screw portion G2b.

The first diaphragm D1 is provided with a first diaphragm plate DP1, the second diaphragm D2 is provided with a second diaphragm plate DP2, and the third diaphragm D3 is provided with a third diaphragm plate DP3. The member R is provided in a form that connects the first diaphragm plate DP1, the second diaphragm plate DP2, and the third diaphragm plate DP3.

By appropriately setting the biasing forces of the first biasing member G1 and the second biasing member G2 in the above-described configuration, when the secondary pressure P2 in the fluid flow path L0 rises above the set pressure, FIG. ), the first diaphragm D1, the second diaphragm D2, and the third diaphragm D3 are pushed against the biasing force of the first biasing member G1 by increasing the pressure in the first chamber H1. It is displaced to the biasing member G1 side. As a result, the exhaust valve V1 is closed and the release valve V2 is opened, thereby stopping the introduction of the primary pressure P1 into the third chamber H3 and reducing the pressure in the third chamber H3 to the second pressure. It is discharged to the outside through the chamber H2 and the open hole K1. As a result, the pressure in the sixth chamber H6 is discharged to the outside through the driving pressure introduction path L4, the opening DP2a, and the opening K1. The main diaphragm D0 is displaced toward the sixth chamber H6 due to the pressure difference with the chamber H6. Therefore, the main valve body V0 of the main governor 10 is operated to the closing side, the secondary pressure P2 in the fluid flow path L0 is decreased, and the secondary pressure P2 is adjusted to the set pressure.
The opening degree of the opening DP2a is designed to increase as the pressure difference between the secondary pressure P2 and the set pressure increases.

On the other hand, when the secondary pressure P2 of the fluid flow path L0 drops below the set pressure, as shown in FIG. The pressure in the first chamber H1 of the pilot governor 100 is lowered, and the biasing force of the first biasing member G1 displaces the first diaphragm D1, the second diaphragm D2, and the third diaphragm D3 toward the first chamber H1. do. As a result, the exhaust valve V1 opens and the open valve V2 closes, introducing the primary pressure of the fluid flow path L0 into the third chamber H3 through the primary pressure introduction path L1. The pressure in chamber H3 rises. Then, the increased pressure of the third chamber H3 is introduced as a driving pressure into the sixth chamber H6 of the main governor 10 via the driving pressure introduction path L4, and the pressure of the sixth chamber H6 also increases, and the pressure of the fifth chamber H5 and the sixth chamber H6, the main diaphragm D0 is displaced toward the fifth chamber H5. Therefore, the main valve body V0 of the main governor 10 is operated to the opening side, the secondary pressure P2 in the fluid flow path L0 is increased, and the secondary pressure P2 is adjusted to the set pressure.

Now, the pilot governor 100 having three diaphragms that has been explained so far, when the simulated secondary pressure P2 accompanied by periodic pressure oscillation is applied to the first chamber H1 as the secondary pressure detection chamber, Patent Document 1 ( It has the following configuration so as to obtain substantially the same frequency response characteristics as the pilot governor having two diaphragms used in the conventional reverse acting pressure regulator disclosed in Japanese Patent Application Laid-Open No. 2017-12718. there is

The effective pressure-receiving areas of the first diaphragm D1, the second diaphragm D2, and the third diaphragm D3 are configured to be substantially equal, and preferably, the effective pressure-receiving areas are equal to those of the diaphragms of the conventional reverse-acting pilot governor. Constructed equal to the area.
Further, the connecting member R that connects the first diaphragm D1, the second diaphragm D2 and the third diaphragm D3 extends, for example, along the displacement direction (direction of arrow Z in FIG. 1) and the first diaphragm plate DP1 and the second diaphragm. It can be composed of a plurality of rod-shaped members R1 (two in this embodiment) that connect the plate DP2 and the third diaphragm plate DP3.

In addition, the relationship between the secondary pressure P2, the stroke of the exhaust valve V1, and the mass of the vibrating portion provides substantially the same performance as that of the conventional pilot governor. Incidentally, the vibratable portion includes the connecting member R, the first diaphragm D1, the second diaphragm D2, and the third diaphragm D3. More strictly, the above relationship is also affected by the masses of the exhaust valve V1, open valve V2, first diaphragm D1, second diaphragm D2, and third diaphragm D3.

Further, in order to introduce a simulated secondary pressure accompanied by periodic pressure oscillation as an input into the first chamber H1 as a secondary pressure measurement chamber, the secondary pressure introduction passage L2 is provided in the secondary pressure introduction passage L2. An on-off valve 51 for switching between opening and closing is provided.
Furthermore, a pressure vibration generator 50 (an example of a pressure vibration applying unit) that applies periodic pressure vibration to the first chamber H1 is provided for the first chamber H1. It is composed of a pressure introduction valve V3 for controlling pressure introduction to the first chamber H1 and a pressure release valve V4 for controlling pressure discharge from the first chamber H1. In addition to the explanation, the pressure introduction valve V3 is provided in a form that opens and closes the primary side pressure introduction path L1 that communicates with the first chamber H1, and the pressure release valve V4 communicates with the first chamber H1. It is provided in such a manner as to open and close the atmosphere release flow path L5.
In a state where the on-off valve 51 is closed, the control device C alternately switches and controls the opening and closing of the pressure introduction valve V3 and the pressure discharge valve V4 based on the pressure value detected by the first pressure sensor S1. Vibration can be generated.

Further, a first pressure sensor S1 capable of measuring a simulated secondary pressure accompanied by periodic pressure vibration introduced into the first chamber H1 is provided closer to the first chamber H1 than the on-off valve 51 is. Furthermore, a second pressure sensor S2 capable of measuring the driving pressure is provided in the driving pressure introduction path L4, and the control device C can receive pressures measured by the first pressure sensor S1 and the second pressure sensor S2. is configured to
The control device C measures the amplitude and phase of the simulated secondary pressure vibration accompanied by the periodic pressure vibration introduced into the first chamber H1 measured by the first pressure sensor S1, and the amplitude and phase measured by the second pressure sensor S2. A frequency response analysis is performed based on the amplitude and phase of vibrations (eg, driving pressure vibrations) at the site.

Now, an example of the frequency response analysis method of the pilot governor 100 explained so far will be explained.

The operator closes the on-off valve 51 to isolate the first chamber H1 and the secondary side of the fluid flow path L0 so as to inhibit pressure propagation.
Next, the control device C sets the frequency of the periodic pressure vibration generated in the pressure vibration generator 50 to an initial value (for example, the minimum value of a plurality of frequencies is set: 0.1 Hz as an example), The pressure vibration generator 50 executes a pressure vibration imparting step of generating periodic pressure vibrations of a set frequency.
After that, the control device C performs a pressure vibration measurement step of receiving the pressure as a simulated secondary pressure associated with the periodic pressure vibration measured by the first pressure sensor S1 at the set frequency, and the second pressure sensor S1. A vibration measurement step of receiving the driving pressure vibration (an example of pressure vibration at another site caused by periodic pressure vibration) measured in S2 is executed.
At a predetermined set frequency, the simulated secondary pressure as an input to be measured and the drive pressure as an output have values as shown in FIG. 3, for example. Incidentally, the frequency set in FIG. 3 is 0.5 Hz. In FIG. 3, the measured values are plotted and their sine approximations are shown by curves.

The control device C increases the frequency of the periodic pressure vibration generated by the pressure vibration generator 50 step by step. Here, it is preferable that the frequency is exponentially increased until the set frequency of the periodic pressure vibration reaches a predetermined upper limit.
Next, the control device C outputs a Bode diagram from the amplitude and phase of the simulated secondary pressure vibration accompanying the periodic pressure vibration measured for each frequency and the amplitude and phase of the vibration at other parts, and outputs the frequency response. Execute a frequency response analysis step for analysis.
Specifically, the amplitude A1 of the simulated secondary pressure vibration accompanied by the periodic pressure vibration measured in the pressure vibration measurement process for each of a plurality of different frequencies measured and the vibration in other parts measured in the vibration measurement process A gain output step of outputting the gain G derived from the ratio of the amplitude A2 to the amplitude A2 for each of a plurality of frequencies; and a phase output step of outputting the difference between the phase of and the phase of vibration at another part measured in the vibration measurement step for each of a plurality of frequencies, and the gain and phase output step output in the gain output step Plot the difference of the phases output in the Bode diagram.

The control device C calculates the stability of the pilot governor 100 based on the Bode diagram created from the gain margin derived from the gain output in the gain output process and the phase margin derived from the phase output process. A stability determination step (an example of a frequency response analysis step) is executed.

[Another embodiment]
(1) The first pressure sensor S1 may directly measure the pressure in the first chamber H1 as the secondary pressure detection chamber.
Further, the driving pressure measured by the second pressure sensor S2 may be the secondary pressure of the downstream pipe of the main valve body V0.

(2) Other structural examples of the pressure generating device 50 include, for example, a roots pump that vibrates the internal pressure of the first chamber H1, and a chamber that heats and cools the chamber communicating with the first chamber H1. It is also possible to employ a configuration in which pressure vibration is generated by expansion/contraction of the gas inside.

It should be noted that the configurations disclosed in the above embodiments (including other embodiments, the same shall apply hereinafter) can be applied in combination with configurations disclosed in other embodiments as long as there is no contradiction. The embodiments disclosed in this specification are exemplifications, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention.

The frequency response analysis method of the pilot governor of the present invention can appropriately input an actual pressure sine wave or the like as an input, and can measure the driving pressure as its output response. It can be effectively used as a frequency response analysis method for a pilot governor of a reverse-acting pressure regulator.

10: Main governor 14: Diaphragm plate 100: Pilot governor 200: Reverse acting pressure regulator D1: First diaphragm D2: Second diaphragm D3: Third diaphragm G1: First biasing member G2: Second biasing member H1 : First chamber H2 : Second chamber H3 : Third chamber K : Housing K1 : Open hole L0 : Fluid flow path L1 : Primary pressure introduction path L1a : Primary pressure introduction end L2 : Secondary pressure introduction path L4 : Driving pressure introduction path P1: Primary pressure P2: Secondary pressure R: Connecting member V0: Main valve body V1: Exhaust valve V2: Release valve

Claims (2)

A frequency response analysis method for a pilot governor used as a reverse acting pressure regulator, comprising:
A first chamber partitioned by a housing and a first diaphragm and communicating with a secondary pressure introduction path, and an open hole partitioned by the housing, the first diaphragm and the second diaphragm and open to the outside. A second chamber formed in a housing, and a primary side pressure introduction passage partitioned by the housing, the second diaphragm, and the third diaphragm are connected in communication, and drive pressure is introduced into the drive pressure chamber of the main governor. a third chamber to which a drive pressure introduction passage is connected; a first biasing member that biases the third diaphragm toward the third chamber;
a connecting member that connects the first diaphragm, the second diaphragm, and the third diaphragm so that they have the same amount of displacement in a displacement direction;
In the displacement direction, the primary side pressure introduction end is opened and closed by being biased by the second biasing member from the side of the second diaphragm toward the primary side pressure introduction end, which is the introduction end of the primary side pressure introduction passage. an exhaust valve for adjusting an inflow amount of the primary pressure side fluid introduced from the primary side pressure introduction end to the third chamber;
an open valve that is connected to the exhaust valve and opens and closes an opening formed in the second diaphragm to adjust the amount of discharge released from the third chamber side to the second chamber side. A frequency response analysis method performed using a governor,
a pressure vibration imparting step of imparting periodic pressure vibration to the first chamber;
a pressure vibration measuring step of measuring the simulated secondary pressure accompanied by the periodic pressure vibration introduced into the first chamber;
a vibration measuring step of measuring vibrations at other sites caused by receiving the periodic pressure vibrations while the periodic pressure vibrations are being applied in the pressure vibration applying step;
Frequency at which frequency response analysis is performed based on the amplitude and phase of the simulated secondary pressure vibration measured in the pressure vibration measurement step and the amplitude and phase of the vibration at the other part measured in the vibration measurement step A frequency response analysis method for performing a response analysis step. The step of applying pressure vibration is a step of applying the periodic pressure vibration to the first chamber at a plurality of different frequencies,
The pressure oscillation measuring step is a step of measuring the simulated secondary pressure generated at a plurality of different frequencies,
The vibration measurement step is a step of measuring the driving pressure generated for each of the periodic pressure vibrations generated at a plurality of different frequencies,
The frequency response analysis step includes
A gain derived from a ratio of the amplitude of the simulated secondary pressure vibration measured in the pressure vibration measurement step and the amplitude of the vibration in the other part measured in the vibration measurement step for each of a plurality of different frequencies. a gain output step of outputting for each of a plurality of frequencies;
The difference between the phase of the simulated secondary pressure vibration measured in the pressure vibration measuring step at each of a plurality of different frequencies and the phase of the vibration at the other part measured in the vibration measuring step at each of a plurality of frequencies a phase output step for outputting to
a stability determination step of determining stability of the pilot governor based on a Bode diagram created from the gain output output in the gain output step and the phase output output in the phase output step; The frequency response analysis method according to claim 1.

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