JP2001355751A - Pressure regulator and gas feeding system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized low cost pressure regulator capable of maintaining a secondary pressure at a desired valve even for a low pressure difference. SOLUTION: This pressure regulator comprises a first pressure regulating part 51a having a valve 57a controlling a fluid flow rate from a primary side cavity 54 to a secondary side cavity 55, a diaphragm 58a sensing a secondary pressure in the secondary side cavity 55 and transmitting a variation in the secondary pressure to the valve 57a, and a coiled spring 59a energizing the valve 57a in the opening direction through the diaphragm 58a; and a second pressure regulating part 51b having a valve 57b controlling the fluid flow rate from the primary side cavity 54 to the secondary side cavity 55, a diaphragm 58b sensing the primary pressure inside the primary side cavity 54 and transmitting a variation in the primary pressure to the valve 57b, and a coiled spring 59b energizing the valve 57b in the opening direction through the diaphragm 58b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for supplying a fluid such as city gas and a pressure regulator used in the system.

[0002]

2. Description of the Related Art City gas consumed by households and other customers is supplied from a gas production plant via a gas pipeline. At present, city gas mainly has a gasification efficiency of 100%.
LNG (Liquefied Natural)
Gas, liquefied natural gas).

[0003] City gas supplied from a gas manufacturing plant is:
As described above, it is provided to customers via a gas pipeline. In the course of passing through the gas pipeline, the gas pressure is reduced stepwise. That is, as shown in FIG. 7, the gas pipeline is a high pressure line 10 (gas pressure: 1).
MPa), medium pressure A line 11 (gas pressure: 0.3 to
(Less than 1.0 MPa), medium pressure B line 12 (gas pressure: 0.
1 to less than 0.3 MPa) and a low pressure line 13 (gas pressure: less than 1.0 kPa to less than 0.1 MPa). The city gas produced in the gas production plant 1 is first sent out to the high-pressure line 10. In addition,
Without passing through the high pressure line 10 to the power plant 2,
In some cases, high-pressure city gas is supplied directly. The high-pressure gas in the high-pressure line 10 is supplied to the medium-pressure A line 11 after being reduced in pressure by the pressure regulator 14. The city gas flowing through the medium pressure A line 11 is further subjected to a medium pressure B by a pressure regulator 15.
And flows through the medium pressure B line 12. The city gas flowing through the medium-pressure B line 12 is further reduced to a low pressure, for example, 2.3 kPa, by the pressure regulator 16, and
Distribute. Further, the medium-pressure B line 12 may supply the industrial customers 3 and the building cooling / heating / district cooling / heating customers 4. City gas used by a customer 17 who is a general home or office is supplied through the low-pressure line 13.

[0004]

It is required to maintain the minimum gas pressure required for the gas appliance used by the customer 17 connected to the low-pressure line 13 in order to use the gas appliance in a healthy state. . However, customers 17
Is significantly increased, the gas pressure at each customer 17 decreases accordingly. For example, assuming that the minimum required gas pressure is 1.5 kPa, it is assumed that only a gas pressure of 1.3 to 1.4 kPa can be obtained. In this case, there are disadvantages such as the heating power of the stove is weak and the temperature of the shower does not rise to a desired temperature. In particular, this is a problem during a time period when gas consumption is large. Therefore, when the gas pressure is expected to decrease, a new gas pipeline is laid in advance, and the low-pressure line 13 is supplied with the low-pressure gas from the other medium-pressure B line 12. However, the construction of this new gas pipeline requires considerable costs. In order to suppress a decrease in gas pressure in the low-pressure line 13, the pressure after the pressure reduction by the pressure regulator 16 is higher than the aforementioned 2.3 kPa, for example, 3.0 kPa.
It is also conceivable to increase the pressure to kPa. However, the pressure increase after the pressure reduction by the pressure regulator 16 is expected to affect the flammability such as the thermal power of the gas appliance, so that the pressure after the pressure reduction by the pressure regulator 16 cannot be simply increased. . Therefore, an object of the present invention is to provide a gas supply system capable of solving the above problems and a pressure regulator suitable for the gas supply system.

[0005]

As described above, the pressure increase after pressure reduction by the pressure regulator is expected to affect the combustibility such as the thermal power of gas appliances. Can not. Therefore, it is necessary for the customer to further reduce the pressure of the low-pressure gas to the pressure desired by the customer's gas appliance and supply the gas to the gas appliance. However, since the gas pressure in the low-pressure line decreases during a time period when the gas consumption is large, it is necessary to supply the low-pressure gas to the gas appliance without reducing the pressure to the desired pressure. The present invention is based on the above idea, a gas supply system for supplying a medium-pressure or high-pressure city gas delivered from a gas manufacturing plant to a customer as a reduced-pressure low-pressure gas, wherein the low-pressure gas is When the customer's gas appliance is supplied to the customer at a pressure higher than the desired pressure, the customer further reduces the low-pressure gas to the desired pressure at the customer and supplies the gas appliance to the gas appliance. The present invention proposes that when gas is supplied to the customer at the gas pressure desired by the customer's gas appliance, it is supplied to the gas appliance without decompression. That is, when the gas pressure of the low-pressure line is, for example, 3.0 kPa and higher than the gas pressure desired by the customer's gas appliance, the pressure is reduced to a certain value in each customer and then supplied to the gas appliance,
When the gas pressure of the low pressure line is, for example, 1.5 kPa and the gas pressure desired by each customer's gas appliance, the gas is supplied to the gas appliance without reducing the pressure. Whether or not the gas pressure of the low pressure line is higher than the pressure desired by the gas appliance of the customer is determined based on the set primary pressure described later in the pressure regulator of the present invention. The pressure may be compared with the pressure desired by the instrument. When the gas pressure of the low-pressure line supplied to the customer is the pressure desired by the gas appliance of the customer, the pressure difference at the customer is very close to zero. Therefore, in the gas supply system of the present invention, the differential pressure before and after decompression at the customer site is:
It may be as small as 0.1 kPa or less. In addition, since the pressure desired by the customer gas appliance has a predetermined range, when determining whether the gas pressure of the low pressure line is higher than the pressure desired by the customer gas appliance, this point is also considered. It needs to be considered.

FIG. 8 shows an example of a pressure regulator 20 for controlling the gas pressure to a constant value and supplying the gas. The pressure regulator 20 is a self-acting pressure regulating valve which is disposed in the middle of a gas pipeline through which gas (fluid) passes, and operates using a secondary pressure as a signal source, a primary pressure or a secondary pressure as a driving force source. The secondary pressure is set to a predetermined value of 2
It has the function of maintaining the next pressure. Pressure regulator 20 shown in FIG.
Is a pressure regulator referred to as a direct-acting type, comprising a pressure regulator main body 21 having a gas flow path 22, a valve seat 25 for partitioning the gas flow path 22 into a primary cavity 23 and a secondary cavity 24, And a valve 26 that opens and closes the valve seat 25. The valve 26 is fixed to a coil spring 28 shorter than its free length via a diaphragm 27 arranged in the secondary cavity 24.
In the pressure regulator 20, the diaphragm 27 serves to sense a secondary pressure in the secondary cavity 24 and transmit a change in the secondary pressure to the valve 26. Coil spring 28
Sets the pressure to be adjusted (secondary pressure). By adjusting the adjusting screw 29, the urging force of the coil spring 28 can be adjusted. The valve 26 is a member that directly adjusts the flow rate of the gas according to its opening degree.

When the secondary pressure is at a predetermined set secondary pressure, the pressure regulator 20 is in an equilibrium state. That is, since the secondary pressure applied to the diaphragm 27 and the urging force of the coil spring 28 are balanced, the valve 26 does not move, and a certain amount of gas flows from the primary side cavity 23 to the secondary side cavity 24. When the secondary pressure exceeds the set secondary pressure due to a decrease in the amount of gas used on the secondary side, the force pushing up the diaphragm 27 overcomes the urging force of the coil spring 28, and the valve 26 attached to the diaphragm 27
Move up. That is, from the primary side cavity 23 to 2
An operation is performed to suppress the amount of gas flowing to the secondary cavity 24 and return the secondary pressure to the set secondary pressure. The secondary pressure may fall below the set secondary pressure due to an increase in the secondary gas usage. In such a case, the coil spring 28
Biasing force overcomes the force pushing up the diaphragm 27. Then, by moving the valve 26 attached to the diaphragm 27 downward, the amount of gas flowing from the primary side cavity 23 to the secondary side cavity 24 is increased, and the secondary pressure is restored to the set secondary pressure. I do.

In the gas supply system of the present invention described above, it is possible to increase the gas pressure by the pressure regulator 16 shown in FIG. 7 to, for example, about 3.0 kPa, while installing the pressure regulator 20 at each customer 17 to reduce the pressure. Conceivable. Each customer 17
Assuming that the gas pressure desired by the gas appliance is about 2.0 kPa, the pressure regulator 20 installed for each customer 17 has a pressure of 3.0 kP.
The primary pressure a is reduced to a secondary pressure of about 2.0 kPa. The problem here is that the pressure difference when reducing the pressure is as small as about 1.0 kPa. That is, even if the pressure is reduced from 3.0 kPa to about 2.0 kPa by the pressure regulator 20, the gas pressure is reduced to less than 2 kPa due to the pressure loss when the gas passes through the valve seat 25, and the desired secondary pressure is reduced. Difficult to maintain. This pressure loss occurs because the diameter of the opening of the valve seat 25 is smaller than the diameter of the pipe through which the gas flows, and becomes more remarkable as the primary pressure becomes lower. Pressure loss can be suppressed by increasing the opening diameter of the valve seat 25. But,
In order to increase the opening diameter, it is necessary to similarly increase the size of the pressure regulator 20, and there is a problem in terms of installation and economy. Since it is installed at the end customer 17, it is desirable that the pressure regulator 20 be small and low-cost. Accordingly, the present invention provides a compact and low-cost regulator that can maintain the secondary pressure at a desired value even at a low differential pressure.

In the conventional pressure regulator 20 shown in FIG. 8, the valve capacity determined by the opening diameter of the valve seat 25 is constant. Therefore, when the primary pressure is low, the pressure loss of the fluid passing through the opening of the valve 26 cannot be ignored. The present inventor has paid attention to the point that if the valve capacity can be increased when the primary pressure decreases, the pressure loss can be suppressed. Accordingly, the present invention is a pressure regulator for separating a primary side and a secondary side by being provided in a fluid supply flow path, and for maintaining the secondary side fluid pressure at a predetermined set secondary pressure. When the fluid pressure on the secondary side exceeds the set secondary pressure, the fluid flow from the primary side to the secondary side is reduced, and the fluid pressure on the secondary side is reduced. Is less than the set secondary pressure, the secondary pressure from the primary side
A first pressure regulating unit that operates so as to increase the fluid flow to the secondary side, and from the primary side to the secondary side when the primary side fluid pressure exceeds a predetermined set primary pressure. Operates so that the fluid flow rate from the primary side to the secondary side increases when the fluid pressure on the primary side is less than the set primary pressure. And a second pressure regulating unit. According to the pressure regulator of the present invention, when the pressure on the primary side exceeds the predetermined primary pressure, the second pressure regulator reduces the fluid flow rate from the primary side to the secondary side. When the pressure on the primary side is lower than the set primary pressure, the operation is performed so that the fluid flow from the primary side to the secondary side increases. That is, when the pressure on the primary side decreases, the valve capacity increases, so that the pressure loss of the fluid passing through the pressure regulator of the present invention becomes extremely small. Since the pressure loss is small as described above, the pressure regulator is reduced in size, and is excellent in installation efficiency and economy.

[0010] In the pressure regulator according to the present invention, the first pressure regulator has a first diaphragm that operates by receiving the fluid pressure on the secondary side, and a valve capacity determined in conjunction with the first diaphragm. A first valve, and first urging means for urging the first valve in an opening direction, wherein the set secondary pressure is set by an urging force of the first urging means. It can be. In the pressure regulator of the present invention, the second
A pressure regulating unit that operates by receiving the fluid pressure on the primary side, a second valve whose valve capacity is determined in conjunction with the second diaphragm, and that opens the second valve. A second urging means for urging in the direction, wherein the set primary pressure is set by an urging force of the second urging means. That is, the first pressure regulator changes the valve capacity by sensing the secondary pressure, and the second pressure regulator changes the valve capacity by sensing the primary pressure. Is configured.

In the pressure regulator according to the present invention, two fluid flow paths are provided, a first valve is disposed in one flow path, and a second valve is disposed in the other flow path.
Can be provided, but the first in one fluid flow path
Arranging the first valve and the second valve is advantageous for miniaturization. In the pressure regulator of the present invention, it is preferable that the maximum valve capacity of the second valve is larger than the maximum valve capacity of the first valve. This is in order to minimize pressure loss in the second valve.

Further, according to the present invention, a pressure regulator main body having a primary side cavity and a secondary side cavity, and a first regulator for controlling a fluid flow from the primary side cavity to the secondary side cavity. A valve, a first diaphragm for sensing a secondary pressure in the secondary side cavity and transmitting a change in the secondary pressure to the first valve, and the first valve via the first diaphragm A first pressure regulating unit having a first urging means for urging the fluid with a predetermined urging force, a second valve for controlling a fluid flow rate from the primary cavity to the secondary cavity, A second diaphragm that senses a primary pressure in the primary cavity and transmits a change in the primary pressure to the second valve; and a second diaphragm that is connected to the second valve through the second diaphragm. Having a second urging means for urging with an urging force. Pressure regulators, characterized in that it comprises a second integer pressure portion, is provided.

In the pressure regulator of the present invention described above, the first pressure regulator senses the fluctuation of the secondary pressure by the first diaphragm and transmits it to the first valve. The first valve is urged by first urging means via the first diaphragm. The first urging means is set to a predetermined urging force. Therefore, the valve capacity of the first valve is adjusted according to the secondary pressure sensed by the first diaphragm. More specifically, if the urging force of the first urging means is set in accordance with the secondary pressure to be maintained, that is, a predetermined set secondary pressure, the first
Operate to maintain the set secondary pressure. Also,
In the second pressure regulating section, the second diaphragm senses the fluctuation of the primary pressure and transmits the fluctuation to the second valve. The second valve is urged by a second urging means via a second diaphragm. The second urging means is set to a predetermined urging force. Therefore, the valve capacity of the second valve is adjusted according to the primary pressure sensed by the second diaphragm. More specifically, if the primary pressure is less than a predetermined set primary pressure, the valve capacity increases, and if the primary pressure exceeds the set primary pressure, the valve capacity decreases. The fluid that passes through the second pressure regulator according to the valve capacity compensates for the pressure loss generated in the first pressure regulator and contributes to maintaining the set secondary pressure.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a view showing a gas supply system according to a first embodiment, and FIG. 2 is a sectional view showing a pressure regulator according to the first embodiment. As shown in FIG. 1, the gas supply system according to the first embodiment basically matches the conventional gas supply system shown in FIG. That is, the gas supply system supplies medium-pressure or high-pressure city gas delivered from the gas manufacturing plant 1 to the customer 17 as reduced-pressure low-pressure gas. The difference from the conventional gas supply system is that the first embodiment has a medium pressure B line 12
The pressure of the gas supplied to the low pressure line 13 is 3.0 k
Pa is set higher than the conventional value of 2.3 kPa, and each customer 17 has a pressure regulator 30. The other points are the same as those of the conventional gas supply system shown in FIG. 7, and therefore, the same parts are denoted by the same reference numerals and description thereof will be omitted.

In the first embodiment, the pressure of the gas delivered from the medium pressure B line 12 to the low pressure line 13 is 3.0 kP
a is set higher than in the past. This is to cope with a case where the number of customers 17 receiving gas supply from the low-pressure line 13 newly increases. That is, when the number of customers 17 increases and the gas supply amount increases, the pressure of the gas supplied to each customer 17 decreases accordingly, and the gas pressure suitable for the gas appliance (not shown) owned by each customer 17 is reduced. It may not be possible to secure them. Therefore, is that the medium-pressure line B 12 is set higher than the conventional pressure of gas delivered to the low pressure line 13, it will compensate the pressure shortage definitive each customer 17. However, since the gas pressure set at a high level is higher than the pressure desired by the gas appliances owned by each customer 17, a problem such as excessive combustion may occur if it is left as it is. Therefore, for each customer 17, a pressure regulator 30
Is provided, and the low-pressure gas is further reduced to the desired pressure of the gas appliance owned by each customer 17 and supplied to the gas appliance.

In the first embodiment, the pressure of the low-pressure gas supplied to the low-pressure line 13 is set to 3.0 kPa,
The goal is for each customer 17 to reduce the pressure to 2.0 kPa. That is, the differential pressure is 1.0 kPa. However, when the gas consumption increases, the gas pressure in the low pressure line 13 may drop to 3.0 kPa or less.
Then, the differential pressure is 1.0 kPa or less, specifically, 0.1 kPa.
In some cases, the pressure may be as extremely small as 1 kPa or less. A known pressure regulator 20 for reducing the gas pressure to a predetermined value and supplying the gas pressure.
Since it is assumed that the differential pressure is large as described above, it becomes difficult to maintain a desired secondary pressure at a low differential pressure of 0.1 kPa or less. In other words, when used in applications where the differential pressure is as low as 1.0 kPa or less as in the first embodiment, the dimensions must be considerably increased, and the cost will inevitably increase. Pressure regulator 30 of the first embodiment
Has solved this problem. In the present embodiment, when the gas pressure in the low-pressure line 13 drops to 2.0 kPa or lower, the gas is supplied to the gas appliance of the customer 17 without reducing the pressure. The pressure regulator 30 can meet this demand. FIG. 2 shows a pressure regulator 30 according to the first embodiment. The pressure regulator 30 is installed for each customer 17 in the gas supply flow path of the low pressure line 13, and the gas inlet side is divided into the primary side and the gas outlet side is divided into the secondary side, and the pressure on the secondary side is set to 2.0 kPa. It is for decompression and maintenance.

The pressure regulator 30 includes a first pressure regulator 31a and a second pressure regulator 31a.
And a pressure regulating unit 31b. First pressure regulating unit 31a
Is a first pressure regulator main body 33a having a gas flow path 32a.
A first valve seat 36a for partitioning the gas flow path 32a into a primary cavity 34a and a secondary cavity 35a, and a first valve 37a for opening and closing the first valve seat 36a. ing. The first valve 37a is fixed to a coil spring 39a shorter than a free length via a first diaphragm 38a disposed in the secondary cavity 35a. Therefore, the first valve 37a is urged in the opening direction by the first coil spring 39a. In addition, the first pressure regulator main body 33a includes:
An air hole 40a communicating with the outside and the diaphragm chamber 41a is formed. In the first pressure regulating unit 31a, the first diaphragm 38a is connected to the second diaphragm 35a in the secondary cavity 35a.
The first valve 3 senses the secondary pressure and changes the secondary pressure.
7a. First coil spring 39a
The biasing force to the first valve 37a is adjusted such that the secondary pressure becomes a predetermined set secondary pressure (2.0 kPa in the present embodiment). When increasing the set secondary pressure, the first screw is tightened by adjusting the adjustment screw 42a.
In order to increase the urging force of the first valve 37a and to lower the set secondary pressure, the urging force of the first valve 37a may be reduced by loosening the adjusting screw 42a.

The second pressure regulator 31b includes a second pressure regulator main body 33b having a gas flow path 32b and the gas flow path 32b.
To the primary side cavity 34b and the secondary side cavity 35
b, and a second valve 37 that opens and closes the second valve seat 36b.
b. The second valve 37b includes a second diaphragm 38b disposed in the secondary cavity 35b.
, Is fixed to a second coil spring 39b longer than the free length. Therefore, the second valve 37b is
Are biased in the opening direction by the coil spring 39b.
The second pressure regulator main body 33b includes a primary side cavity 34b.
And a pressure guiding tube 43b communicating the diaphragm chamber 41b with the pressure guiding tube 43b. In the second pressure regulating section 31b, the second diaphragm 38b senses the primary pressure in the primary side cavity 34b via the pressure guiding tube 43b, and transmits the fluctuation of the primary pressure to the second valve 37b. Play a role. The second coil spring 39b increases the valve capacity when the primary pressure is less than a predetermined set primary pressure (3.0 kPa in the present embodiment), and conversely, when the primary pressure exceeds a predetermined set pressure. The biasing force is adjusted so as to reduce the valve capacity. In addition,
The set primary pressure fluctuates by adjusting the adjusting screw 42b. The through hole 136b formed in the second valve seat 36b has a larger opening diameter than at least the through hole 136a of the first valve seat 36a so that the pressure loss of the gas passing therethrough is reduced. Keep it. That is, the maximum valve capacity of the second pressure regulator 31b is larger than the maximum valve capacity of the first pressure regulator 31a.

Next, the operation of the pressure regulator 30 will be described separately for the first pressure regulator 31a and the second pressure regulator 31b. 2
The secondary pressure is a predetermined secondary pressure (here, 2.0 kPa)
, The first pressure regulating unit 31a is in an equilibrium state. That is, the first valve 37a stops at the position where the secondary pressure applied to the first diaphragm 38a and the urging force of the first coil spring 39a are balanced, and a certain amount of gas is discharged from the primary side cavity 34a. It flows to the secondary side cavity 35a. This fixed amount of gas determines a predetermined set secondary pressure. For example, when the secondary pressure exceeds a predetermined set secondary pressure due to a decrease in the amount of gas used on the secondary side, the force pushing up the first diaphragm 38a overcomes the urging force of the first coil spring 39a, and The first valve 37a attached to the diaphragm 38a is moved upward, that is, in the closing direction. Accordingly, the amount of gas flowing from the primary side cavity 34a to the secondary side cavity 35a is reduced, and the secondary pressure operates to recover to a predetermined set secondary pressure.

When the secondary pressure falls below a predetermined set secondary pressure, for example, due to an increase in the amount of gas used on the secondary side, the urging force of the first coil spring 39a overcomes the force pushing up the first diaphragm 38a. Then, the first valve 37a attached to the first diaphragm 38a moves downward, that is, in the opening direction. Therefore, an operation is performed so that the amount of gas flowing from the primary side cavity 34a to the secondary side cavity 35a increases and the secondary pressure is restored to a predetermined set secondary pressure. As described above, the first pressure regulating unit 31a
Operates the first valve 37a until the force that the secondary pressure presses the first diaphragm 38a upward and the force that the first coil spring 39a biases the first diaphragm 38a downward are balanced. The opening and closing operations prevent an increase in the secondary pressure.

Next, the operation of the second pressure regulating section 31b will be described. When the primary pressure is set to the predetermined primary pressure, the second pressure regulating unit 31b is in an equilibrium state.
That is, the second valve 37b stops at a position where the primary pressure applied to the second diaphragm 38b and the urging force of the second coil spring 39b are balanced, and a certain amount of gas is discharged from the primary side cavity 34b. It flows to the secondary side cavity 35b. Next, a predetermined setting 1 in which the primary pressure is set
If the primary pressure is exceeded, the primary pressure will
The force pushing up b overcomes the biasing force of the second coil spring 39b, and the second valve 37b attached to the second diaphragm 38b moves upward, that is, in the closing direction. Therefore, the gas flow rate to the secondary side decreases. When the primary pressure is sufficiently higher than the set primary pressure, as shown in FIG. 3, the second valve 37b comes into contact with the second valve seat 36b to prevent the gas from flowing. Therefore, the gas passes only through the first pressure regulating unit 31a. When the primary pressure is sufficiently high, the desired secondary pressure is not reduced due to the pressure loss of the first pressure-regulating section 31a, so that the gas is supplied to the secondary side via the second pressure-regulating section 31b. No need to supply.

On the other hand, when the primary pressure is less than the set primary pressure, the urging force of the second coil spring 39b overcomes the force pushing up the second diaphragm 38b due to the primary pressure. . Therefore, the second valve 37b attached to the second diaphragm 38b
Moves downward, that is, in the opening direction. Therefore, the gas flow rate to the secondary side increases. When the primary pressure is considerably low, the second valve 37b is fully opened as shown in FIG.
The gas maintaining the primary pressure is supplied to the secondary cavity 35b. That is, when the primary pressure is low, the pressure loss due to the first pressure-regulating section 31a becomes remarkable.
It is supplied to the next side. As described above, when the primary pressure is less than the predetermined set primary pressure, the second pressure regulator 31b increases the valve capacity by a self-powered system, and the primary pressure increases to the predetermined set pressure. If it exceeds, the valve capacity is reduced by the self-powered system. That is, the second pressure regulating unit 31b has a function of adjusting the valve capacity according to the primary pressure by a self-powered system.

The pressure regulator 30 according to the first embodiment has a first
The pressure loss in the first pressure regulating unit 31a is complemented by the valve capacity adjusting function of the second pressure regulating unit 31b, while the pressure regulation on the secondary side is prevented by the pressure regulating unit 31a. Therefore, a small pressure regulator 30 can be realized, and the problems concerning the installability and economy of each customer 17 can be solved. In particular, the pressure regulator 30 of the first embodiment includes a first pressure regulator 31a and a second pressure regulator 31a.
Since the pressure regulating sections 31b operate independently, there is also an advantage that other energy is not required.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the pressure regulator 30 according to the first embodiment, the first pressure regulator 31a has a gas flow path 32a, and the second pressure regulator 31b has a gas flow path 32b. That is, the pressure regulator 30 has two gas flow paths 32a, 32a.
b. The pressure regulator 50 according to the second embodiment includes:
The first embodiment differs from the first embodiment in that a first pressure regulator 51a and a second pressure regulator 51b are provided for one gas flow path 52.

FIG. 5 shows a pressure regulator 50 according to the second embodiment.
FIG. The pressure regulator 50 includes a pressure regulator main body 53 having a gas flow channel 52, a valve seat 56 that partitions the gas flow channel 52 into a primary cavity 54 and a secondary cavity 55, and opens and closes the valve seat 56. It has a first valve 57a and a second valve 57b. The first valve 57a is fixed to a first coil spring 59a shorter than a free length via a first diaphragm 58a arranged in the secondary cavity 55. Therefore, the first valve 57a is connected to the first coil spring 59
a is urged in the opening direction. Second valve 57
b is fixed to a second coil spring 59b longer than its free length via a second diaphragm 58b arranged in the secondary side cavity 55. Therefore, the second valve 57b is urged in the opening direction by the second coil spring 59b. The opening diameter of the through hole 156b formed in the valve seat 56 is set larger than at least the through hole 156a so that the pressure loss of the gas passing therethrough is reduced. The pressure regulator main body 53 is formed with an air hole 60a for communicating the diaphragm chamber 61a with the outside, and the primary cavity 54 and the diaphragm chamber 61 are formed.
and a pressure guiding tube 63b communicating with the pressure guiding tube b.

The pressure regulator 50 includes a valve seat 56 and a first
, A first diaphragm 58a, and a first diaphragm 58a.
And the coil spring 59a constitute a first pressure regulating unit 51a. Further, the valve seat 56 and the second valve 57b
, The second diaphragm 58b, and the second coil spring 5
9b constitutes a second pressure regulating unit 51b. In the first pressure regulator 51b, the first diaphragm 58a senses a secondary pressure in the secondary cavity 55 and transmits a change in the secondary pressure to the first valve 57a. In the first coil spring 59a, the urging force to the first valve 57a is adjusted by the adjusting screw 62a so that the secondary pressure becomes a predetermined set secondary pressure. Second pressure regulating section 51
b, the second diaphragm 58b is connected to the pressure guiding tube 63.
b to sense the primary pressure of the primary cavity 54,
The change in the primary pressure is transmitted to the second valve 57b. The second coil spring 59b is provided with an adjusting screw 62b such that the valve capacity increases when the primary pressure is less than a predetermined set primary pressure, and conversely, the valve capacity decreases when the primary pressure exceeds a predetermined set pressure. The biasing force is adjusted by.

First pressure regulating section 51a and second pressure regulating section 5
The operation of 1b is performed by the first pressure regulating unit 3 according to the first embodiment.
This is the same as 1a and the second pressure regulating section 31b. Therefore, only the outline is described here and the details are omitted.
The first pressure-regulating section 51a is provided with a force that the secondary pressure presses the first diaphragm 58a upward and a first coil spring 59a.
Opens and closes the first valve 57a until the force for urging the first diaphragm 58a downward is balanced, thereby preventing an increase in the secondary pressure. On the other hand, the second pressure regulating unit 51b has a function of adjusting the valve capacity according to the primary pressure by a self-powered system. It has a function of adjusting the valve capacity according to the primary pressure by a self-powered system. Therefore, similarly to the pressure regulator 30 according to the first embodiment, a small pressure regulator 50 is used.
Can be realized, and the problems of installation and economy at each customer 17 can be solved.
Since both a and the second pressure regulating unit 51b operate on their own, there is also an advantage that other energy is not required. Further, the pressure regulator 50 according to the second embodiment includes:
Since the first pressure regulating section 51a and the second pressure regulating section 51b are provided for one gas flow path 52, the first pressure regulating section 51a and the second pressure regulating section 51b are provided.
The number of parts can be reduced as compared with the pressure regulator 30 of the embodiment, and further downsizing can be realized. That is, the pressure regulator 50 according to the second embodiment is disposed on the first valve 57a and the second valve 57b for one gas flow path 52, and the valve seat 56 is provided with the first valve 57a and the second valve 57a. Since the valve 57b is commonly used, the number of parts can be reduced and the size can be reduced.

In the pressure regulator 50 described above, the first valve 57
a) Although the first coil spring 59a and the second coil spring 59b are used as means for urging the second valve 57b, the urging means is not limited to the coil spring. For example,
As long as the first coil spring 59a, a weight can be used as a substitute. The second coil spring 59b can be made of an elastic material such as rubber. Further, in the pressure regulator 50, the first coil spring 59a is arranged shorter than the free length, while the second coil spring 59b is arranged longer than the free length. However, the present invention is not limited to this. . For example, in the pressure regulator 70 shown in FIG. 6, the first coil spring 79a is longer than the free length. That is, the first diaphragm 78a may be configured to receive the secondary pressure in the secondary cavity 75 in the diaphragm chamber 81a via the pressure guiding tube 83a. In the case of this structure,
When the secondary pressure becomes higher than a predetermined set secondary pressure, the first
The secondary pressure overcomes the force of the coil spring 79a for urging the first diaphragm 78a upward, and the first valve 7
7a moves downward, that is, in the closing direction. Conversely, when the secondary pressure becomes lower than the predetermined secondary pressure, the first coil spring 79
a for urging the first diaphragm 78a upward is 2
Overcoming the next pressure, the first valve 77a moves upward, ie, in the opening direction. The relationship between the secondary pressure of the first valve 77a and the opening / closing direction matches that of the pressure regulator 50. Also,
Other structures and operations are the same as those of the pressure regulator 50, and therefore, description thereof is omitted. Further, the first and second embodiments include:
Although a city gas has been described as an example of the fluid, the invention can be applied to other gases or liquids such as water.

[0029]

As described above, according to the gas supply system of the present invention, the gas pressure supplied to the low-pressure line is set high while the gas pressure is reduced to a gas pressure suitable for each customer's gas appliance. Therefore, even if the number of customers in the low-pressure line increases, it is possible to prevent gas pressure shortage from occurring. Further, according to the present invention, it is possible to provide a compact and low-cost regulator that can maintain the secondary pressure at a desired value even at a low differential pressure.

[Brief description of the drawings]

FIG. 1 is a diagram showing a gas supply system according to the present invention.

FIG. 2 is a pressure regulator 30 according to the first embodiment of the present invention.
FIG. 3 is a diagram showing a cross-sectional structure of FIG.

FIG. 3 is a pressure regulator 30 according to the first embodiment of the present invention.
It is a figure for explaining operation of.

FIG. 4 is a pressure regulator 30 according to the first embodiment of the present invention.
It is a figure for explaining operation of.

FIG. 5 shows a pressure regulator 50 according to a second embodiment of the present invention.
FIG. 3 is a diagram showing a cross-sectional structure of FIG.

FIG. 6 shows a pressure regulator 50 according to a second embodiment of the present invention.
It is a figure which shows the modification of.

FIG. 7 is a diagram for explaining a gas pipeline.

FIG. 8 is a view showing a cross-sectional structure of a conventional pressure regulator 20.

[Explanation of symbols]

1 ... Gas production plant, 2 ... Power plant, 3 ... Industrial customer, 4 ...
Building air-conditioning / district air-conditioning customers, 10 ... High pressure line, 11
... Medium pressure A line, 12 ... Medium pressure B line, 13 ... Low pressure line, 14,15,16 ... Pressure regulator, 17 ... Customer, 20,3
0, 50, 70 ... pressure regulator, 21, 53 ... pressure regulator main body, 2
2, 32a, 32b, 52 ... gas flow path, 23, 34a,
34b, 54: Primary cavity, 24, 35a, 35
b, 55, 75 ... secondary side cavity, 25, 56 ... valve seat, 26 ... valve, 27 ... diaphragm, 28 ...
Coil springs, 31a, 51a... First pressure regulator, 31b,
51b: second pressure regulator, 33a: first pressure regulator main body, 3
3b: second pressure regulator main body, 36a: first valve seat, 36b: second valve seat, 37a, 57a, 7
7a: first valve, 37b, 57b: second valve,
38a, 58a, 78a ... first diaphragm, 38
b, 58b... second diaphragm, 39a, 59a, 7
9a: first coil spring, 39b, 59b: second coil spring, 40a, 60a: air hole, 41a, 41b, 6
1a, 61b, 81a ... diaphragm chamber, 42a, 42
b, 62a, 62b ... adjustment screw, 43b, 63b, 83
a ... pressure guide tube

Continued on the front page F term (reference) 3H059 AA06 BB05 CA13 CB12 CC02 CD04 CD12 CE05 FF05 3H060 AA02 BB03 CC07 DC05 DC10 DD04 DD12 DD17 EE06 HH07 HH14 5H316 AA11 BB05 CC04 DD06 DD07 EE02 EE10 EK12 KK02 JJ04 KK

Claims (8)

[Claims] A primary side and a secondary side provided in a fluid supply channel;
The secondary side is separated from the secondary side, and the secondary side fluid pressure is set to a predetermined value 2
A pressure regulator for maintaining a secondary pressure, wherein a fluid flow rate from the primary side to the secondary side decreases when the fluid pressure on the secondary side exceeds the set secondary pressure. A first pressure regulating unit that operates to increase the fluid flow rate from the primary side to the secondary side when the fluid pressure on the secondary side is less than the set secondary pressure. If the fluid pressure on the primary side exceeds a predetermined set primary pressure,
Operates so that the fluid flow from the secondary side to the secondary side decreases, and when the primary side fluid pressure is less than the set primary pressure, the fluid from the primary side to the secondary side A second pressure regulator operable to increase the flow rate. 2. The first pressure regulator includes a first diaphragm that operates by receiving the fluid pressure on the secondary side, and a first valve whose valve capacity is determined in conjunction with the first diaphragm. , A first valve for urging the first valve in an opening direction.
2. The pressure regulator according to claim 1, further comprising: an urging unit, wherein the set secondary pressure is set by an urging force of the first urging unit. 3. 3. The second pressure regulator includes a second diaphragm that operates by receiving the fluid pressure on the primary side, and a second diaphragm whose valve capacity is determined in conjunction with the second diaphragm.
And a second urging means for urging the second valve in an opening direction, wherein the set primary pressure is set by an urging force of the second urging means. The pressure regulator according to claim 1 or 2, wherein 4. The pressure regulator according to claim 1, wherein the first valve and the second valve are arranged in one fluid flow path. 5. The pressure regulator according to claim 1, wherein a maximum valve capacity of the second valve is larger than a maximum valve capacity of the first valve. 6. A pressure regulator main body having a primary side cavity and a secondary side cavity, a first valve for controlling a fluid flow from the primary side cavity to the secondary side cavity,
A first diaphragm for sensing a secondary pressure in the secondary cavity and transmitting a change in the secondary pressure to the first valve; and opening the first valve via the first diaphragm. A first pressure regulating unit having a first urging means for urging in a direction, a second valve for controlling a fluid flow rate from the primary cavity to the secondary cavity, and the primary side. A second diaphragm for sensing a primary pressure in the cavity and transmitting a change in the primary pressure to the second valve;
And a second urging unit having a second urging means for urging the second valve in the opening direction via the diaphragm. 7. A gas supply system for supplying medium-pressure or high-pressure city gas delivered from a gas manufacturing plant to a customer as a reduced-pressure low-pressure gas, wherein the low-pressure gas is desired by the customer's gas appliance. If the low-pressure gas is supplied to the customer at a pressure higher than the pressure to be supplied to the gas appliance, the low-pressure gas is further reduced to the desired pressure at the customer and supplied to the gas appliance, and the low-pressure gas is supplied to the customer's gas appliance. A gas supply system for supplying gas to the gas appliance without reducing the pressure when the gas is supplied to the customer at a desired pressure. 8. The differential pressure before and after decompression at the customer site is:
The gas supply system according to claim 7, wherein the pressure is 0.1 kPa or less.