JPH09196197A - Ball valve for gas conduit - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] Realization of a ball valve for a gas conduit that has a small installation pit and can be installed anywhere. A valve body (20) inserted into a gas conduit (4) and a spherical valve body (22) having a through hole (25) for gas flow and housed in the valve body (20) are provided. In a ball valve for a gas conduit that is rotated to control the gas flow in the gas conduit 4 or to control the flow rate, a plurality of thermal type flow rate detecting elements 104 are disposed in the through hole 25 in the through hole 25. In preparation for this, the flow rate detector 100
A physical quantity corresponding to the gas flow rate in the through hole 25 is detected by.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball valve used as a gas shutoff valve or a flow rate adjusting valve on a conduit of a gas supply conduit, and more particularly to a flow rate detecting sensor in a spherical valve body having a through hole. The present invention relates to a ball valve which has a built-in valve and can simultaneously measure the gas flow rate in addition to its original function.

[0002]

2. Description of the Related Art As shown in FIG. 11, a general gas supply system uses a gas (pressure = 10 kgf) produced in a factory 1.
/ Cm ² (1 MPa) or more is sent to the governor station 3 via the high-pressure conduit 2, and the gas depressurized in the governor station 3 (pressure = less than 10 kg / cm ² (1 MPa) to 1 kg / cm ² (0.1 MPa)). ) Or more) is delivered to the district governor 5 in each consumption area via the medium pressure conduit 4, and the gas (1 kg / c) further depressurized in the district governor 5 is delivered.
m ² (less than 0.1 MPa) is supplied to each consumer 7 through the low pressure conduit 6.

Such a gas supply system can cut off the supply of gas based on a command from the central monitoring center 8 as a countermeasure against a disaster such as an earthquake. That is, the high-pressure conduit 2 is provided with the emergency cutoff valve 10 so that the gas sent from the factory 1 can be cut off. Further, a regional block valve 11 (shutoff valve) is provided in the medium-pressure conduit 4 reaching the district governor 5 in each consumption area, so that the gas can be shut off there as well.
Since the regional block valves 11 are separately provided in front of the district governor 5 separated from the governor station 3 for each consumption area, the number of the regional block valves 11 installed is more than 5000.

In addition to the above-mentioned gas shut-off function, the gas supply system measures the flow rate of the gas in order to control whether or not the supply gas is stably supplied to each downstream consumption area. The function to do is also provided. for that reason,
In the installation pit (recess, hole) 12 in which the regional block valve 11 is installed, as shown in FIG. 2, usually, a hot gas for measuring the flow rate is taken out from the pipe in which the regional block valve 11 is inserted. A tapping 13 and a gas pressure gauge 14 are provided side by side. These are arranged near the regional block valve 11 in the same pipeline.

The hot tapping 13 has a sensor 15 for detecting a flow rate in the conduit of the intermediate pressure conduit 2 as seen in a known gas flow meter (see, for example, Japanese Patent Laid-Open No. 4-2922).
And the static pressure and dynamic pressure of the gas obtained by the sensor 15 are supplied to the signal processing unit 1 on the ground via the pressure guiding pipes 16 and 17.
There is provided a flow rate measuring means for guiding the gas flow rate to No. 8 and calculating the gas flow rate from the pressure difference between the two. If steam or tar in the gas adheres to the flow rate detecting sensor 15, an error occurs. Therefore, in order to facilitate and facilitate maintenance work such as cleaning and replacement, the hot tapping 13 is provided with a gas. An opening / closing valve 19 is inserted in the takeout passage, and a space 20 for maintenance and inspection is formed above the valve position. The hot tapping 13 is provided so that the flow rate detecting sensor 15 can be pulled up inside the space 20 to perform maintenance work.
Has a relatively long shape in the vertical direction.

The flow rate detecting sensor 15 has a gas conduit arranged in a straight pipe portion having a length 10 times or more the diameter. To calculate the flow rate by measuring the flow velocity at a certain point in the pipeline, it is necessary to know the flow velocity distribution in the pipeline cross section, and to stabilize the flow velocity distribution in a known pattern, the gas flow must be in a laminar state. Alternatively, it is necessary to make a developed turbulent state, and for that purpose, a straight pipe portion of a predetermined length is required.

If the required straight pipe section cannot be obtained,
A volumetric flow meter or a correlation flow meter may be used as the flow rate detection sensor. This is because the volumetric flow meter can detect the flow rate without depending on the flow velocity distribution, and the correlation flow meter can suppress fluctuations due to changes in the flow velocity distribution by combining a plurality of flow meters. However, the volumetric flowmeter has drawbacks such as slow response speed, large pressure loss, and difficulty in incorporation into an existing pipeline.
There are drawbacks such as complexity, and all are used only in a limited way.

[0008]

As described above, when a conventional ball valve for a gas conduit is used, in many cases, in addition to the ball valve, a flow rate detection sensor and the like are provided side by side in the same pit, The installation place is limited to the straight pipe part of a predetermined length.

However, if a plurality of pieces of equipment are installed side by side in the same pit, the pit must be enlarged. For this reason, not only the construction cost for pit construction increases, but also the installation location is restricted. Especially, the installation cost of a large number of regional block valves will be enormous because of the huge construction cost.

In the case of a gas conduit, the length is 10 diameters.
There are almost no straight pipe sections that are more than double the length. For this reason, the installation place is limited, or even the installation place does not exist, which makes it difficult to select the installation place.

The present invention has been made in view of such unsolved problems, and an object thereof is to provide a ball valve for a gas conduit which can be installed anywhere.

[0012]

A ball valve for a gas conduit, which was invented in order to solve the above-mentioned problems, will be described below in terms of its structure and operational effects.

[First Solving Means] A ball valve for a gas conduit according to the first solving means (as described in claim 1 at the beginning of the application) includes a valve main body inserted in the gas conduit and a gas circulating member. A spherical valve body having a through hole formed therein and housed in the valve body, the ball valve for a gas conduit for controlling the cutoff or flow of the gas flow in the gas conduit by rotating the valve body. In the above, a plurality of thermal type flow rate detecting elements are provided in the through hole with a flow rate detecting body arranged on a substrate, and the flow rate detecting body detects a physical quantity according to a gas flow rate in the through hole. It is what

In measuring the gas flow rate in the gas conduit, the flow rate detector detects a physical quantity corresponding to the gas flow rate in the through hole. When the gas flow rate in the through hole is measured, the gas flow rate in the gas conduit is measured regardless of the diameter of the gas conduit. Here, the cross-sectional shape of the through hole is known,
Moreover, since multiple thermal type flow rate detection elements are installed in the through-hole, when the flow velocity distribution in the through-hole changes, unlike when measuring one point, multiple thermal The physical quantity detected by the flow rate detecting element also changes. This makes it possible to measure the gas flow rate in the through hole fairly accurately whether the gas flow in the through hole is laminar flow, developed turbulence, or turbulent flow in the intermediate state. It becomes possible to do. Therefore, the ball valve can be inserted and installed at an arbitrarily selected site of the gas conduit without being restricted by the diameter of the gas conduit and not restricted by the bent state of the gas conduit.

Therefore, according to the present invention, since the installation location is not selected, it is not always necessary to install it in the pit, and it can be installed in the front and rear valves of, for example, a direct buried type or a governor station. Further, for the gas supply system downstream of the installed ball valve, the gas can be shut off and the flow rate can be measured for each system, which facilitates the formation of a conduit network in the gas supply system. Further, it becomes possible to easily manage the stable gas supply and the safety management for each consumer.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A specific mode for carrying out the ball valve for a gas conduit according to the first solving means will be described below in terms of its structure and operation and effect.

[Second Solution] A ball valve for a gas conduit of the second solution (as described in claim 2 at the time of filing the application) has a ball for a gas conduit of the first solution described above. In the valve, the valve body is supported by an upper stem shaft and a lower stem shaft that are installed in the valve body, the upper stem shaft is configured to be detachable, and the thermal flow rate detecting element is attached to the upper stem shaft. The feature is that they are connected.

In the ball valve for the gas conduit of the second solving means, the flow rate detecting body is connected to the detachable upper stem shaft, so that the flow rate detecting body can be easily inserted and removed. It is possible. Accordingly, even if the ball valve and the flow rate detector are integrated, maintenance of the flow rate detector can be facilitated.

Therefore, according to the present invention, it is possible to realize a ball valve for a gas conduit which can be installed in any place and the flow rate detector can be easily maintained.

[Third Solving Means] The ball valve for gas conduit of the third solving means (as described in claim 3 at the beginning of the application) is the gas conduit of the above-mentioned first or second solving means. A ball valve for use in the flow rate detecting device, wherein the flow rate detecting body is one in which the plurality of thermal type flow rate detecting elements are connected in parallel and is driven at a constant voltage.

In the ball valve for gas conduit according to the third means as described above, the current supplied to the entire plurality of thermal type flow rate detecting elements changes in accordance with the change in gas flow rate.
Moreover, the current value also reflects the current of each detection element corresponding to the gas flow velocity distribution. Thereby, the gas flow rate can be easily measured by a simple calculation means based on the total supply current.

Therefore, according to the present invention, it is possible to realize a ball valve for a gas conduit which can be installed at any place and whose gas flow rate can be easily measured.

[Fourth Solving Means] The ball valve for gas conduit of the fourth solving means (as described in claim 4 at the beginning of the application) is the gas conduit of the above-mentioned first or second solving means. A ball valve for use in the flow rate detecting device, wherein the flow rate detecting body is configured such that the plurality of thermal type flow rate detecting elements are connected in series and driven by a constant current.

In the ball valve for gas conduit according to the fourth means, the voltage applied to the entire plurality of thermal type flow rate detecting elements changes in accordance with the change in gas flow rate.
Moreover, the voltage value also reflects the applied voltage for each detection element corresponding to the gas flow velocity distribution. This allows
The gas flow rate can be easily measured by a simple calculation means based on the total applied voltage.

Therefore, according to the present invention, it is possible to realize a ball valve for a gas conduit which can be installed at any place and whose gas flow rate can be easily measured.

[0026]

Embodiments of the ball valve for a gas conduit according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is an overall view thereof.

This ball valve is provided with a valve body 20 having a connection port for the intermediate pressure conduit 4a on the upstream side and the intermediate pressure conduit 4b on the downstream side, and a spherical valve body 22. The valve body 22 includes a valve body 2 as is found in a normal ball valve.
It is decorated with 0. The upper and lower sides thereof are connected to the upper stem shaft 24 and the lower stem shaft 23, and are supported by the valve main body 20 via these and are bidirectionally rotatable.

Further, the valve body 22 is provided with a through hole 25. When the through hole 25 is located in the same direction as the axis of the intermediate pressure conduits 4a, 4b, the valve is in the open position and the through hole 25 is formed.
The valve is in the closed position in a state in which is positioned at a right angle to the axes of the medium pressure conduits 4a and 4b. This makes this ball valve
The valve body 22 is rotated to block or control the gas flow in the gas conduit.

At the top of the valve body 20, flanges 26, 2 are provided.
A gear box 28 is connected via 7, and one end of the upper stem shaft 24 projects into and is supported in the gear box 28. The upper stem shaft 24 is rotatably and detachably supported by the valve body 20 via an O-ring 24a, as in a normal ball valve structure.
Is configured so that it can be pulled out upward.
Further, the pinion gear 32 is attached to one end of the upper stem shaft 24.
, And the pinion gear 32 meshes with a worm gear (not shown) in the gear box 28. This worm gear includes a geared motor 3 attached to a gear box 28.
0 and the rotating shaft of the handle 31 are connected. The valve body 22 is rotationally driven via the pinion gear 32 or the like and the upper stem shaft 24 by the rotation operation of the geared motor 30 or the handle 31.

The upper stem shaft 24 has a hollow passage 33 at its axis.
Are perforated to form a hollow shaft. A signal line 109, which is connected to the lower end of the upper stem shaft 24 by a bolt or the like and extends to the ground from the flow rate detector 100, is inserted into the hollow passage 33.
A seal structure 24b such as a howmatic seal is provided in the inside to prevent gas from being discharged from the inside of the hollow passage 33 to the ground.

The signal processing unit 108 is provided outside the ball valve.
Is provided, and the signal line 10 from the thermal flow rate detector 100 is provided.
9 is connected to the signal processing unit 108. As a result, the thermal flow rate detector 100 is connected to the signal processing unit 108 by the signal line 109, and is capable of transmitting and receiving signals.

Next, the structure of the thermal type flow rate detector 100 will be described in detail. 2 is a perspective view thereof, and FIG.
Is a sectional view of the same. Further, FIG. 4 is a plan view and a sectional view of the thermal type flow rate detecting element. Further, FIG. 5 is a block diagram of a circuit including the signal processing unit 108.

The thermal flow rate detector 100 is constructed by arranging a plurality of thermal flow rate detection elements 104 on a straight line having a length close to the diameter of the through hole 25 and connecting these elements in parallel. Specifically, a supporting member 102 made of a hard material such as steel or non-rust steel, a glass substrate 103 supported by the supporting member 102, and a plurality of thermal flow rate detecting elements 104 attached to the glass substrate 103. A protective cover 105 on the surface of the thermal flow rate detection element 104, a spacing member 106 for forming a fluid flow path between the thermal flow rate detection element 104 and the protective cover 105, and the temperature of the fluid is detected. Therefore, it is composed of a temperature detecting element 107 provided on the glass substrate 103.

On the surface of the glass substrate 103, a wiring pattern 131, a wiring pattern side connection pad 132, and a connection terminal pad 133, which are formed by subjecting a metal film formed by vapor deposition to photolithography and etching, are provided. . Each thermal type flow detection element 10
The fourth contact pad 144 and the wiring pattern side connection pad 132 are connected by a gold wire 146. Further, a temperature detection pad 134 is also provided on the surface of the glass substrate 103. Then, the connection terminal pad 1
33 and the temperature detection pad 134 correspond to the signal line 1 described above.
It is connected to the signal processing unit 108 via 09. The glass substrate 103 may be made of a non-conductive material other than glass.

Thermal flow rate detecting element 104 and signal processing unit 10
A circuit configuration composed of 8 will be described. Each thermal flow rate detection element 104, that is, thermal flow rate detection elements 104-1 to 104-
n are arranged in a line, and each heater wire 143 included therein, that is, the heater wires 143-1 to 143-n.
Are connected in parallel, so that an equivalent circuit has resistors r1 to rn connected in parallel.

The signal processing unit 108 includes a constant voltage source 181 and
It includes an arithmetic circuit 182, a display portion 183, and a current-voltage conversion resistor 184. Then, the output voltage Vc of the constant voltage source 181 is applied to the heater wire 143 of each thermal flow rate detection element 104 via the current-voltage conversion resistor 184. As a result, the voltage Vs appearing across the current-voltage conversion resistor 184 has an output that depends on the change in the combined resistance of the resistors r1 to rn. Such a circuit configuration has the heater wire 143 of each of the thermal type flow rate detection elements 104-1 to 104-n.
Even if any of -1 to 143-n is disconnected, the measurement can be continued by correcting the combined resistance value.

With respect to the ball valve for the gas conduit of this embodiment, its specific usage and operation will be described.

This ball valve is installed in the installation pit 12 in place of the conventional regional block valve (11) for the medium pressure conduit (4) buried in the soil. That is, in order to insert the valve body 20 between the intermediate pressure conduit 4a on the upstream side and the intermediate pressure conduit 4b on the downstream side that traverses the inside of the installation pit 12, the base 21 is placed on the bottom of the pit 12. The valve body 20 is placed on the valve body 20 and connected so that the upstream side and the downstream side of the intermediate pressure conduits 4a and 4b communicate with each other. Further, if necessary, the attachment portion 37 is operated to perform adjustment so that the surface of each thermal type flow rate detecting element 104 of the thermal type flow rate detecting body 100 is parallel to the gas flow direction.

When electric power is supplied to the signal processing unit 108, a constant voltage Vc is applied to each of the thermal type flow rate detecting elements 104-1 to 104-n, so that each thermal type flow rate detecting element 104.
The heater wires 143-1 to 143-n of -1 to 104-n have a temperature of 100 ° C, for example. At this time, heat is taken away from the heater wires 143-1 to 143-n in contact with the gas flow according to the flow velocity of each part. Heater wire 14 deprived of heat
When the temperature of No. 3 decreases, the resistance value of the heater wire 143 decreases and the current value flowing through each thermal type flow rate detecting element 104 increases. Here, since the thermal flow rate detecting elements 104 are connected in parallel, the current value Is supplied from the constant voltage source 181 is Is.
Is equal to the sum of the values of the currents flowing through the thermal flow rate detecting elements 104. Therefore, this current value Is is used as the current-voltage conversion resistor 1
It is detected as a voltage Vs by 84, and the arithmetic circuit 18
In Step 2, a predetermined calculation based on an empirical formula or the like is performed to obtain a gas flow rate value. This is displayed on the display unit 183. Alternatively, it may be sent to the central monitoring center 8 or the like in FIG.

Thus, by using the ball valve for the gas conduit, it is possible to measure the gas flow rate in the gas conduit in addition to blocking the gas flow or controlling the flow rate.

The circuit shown in FIG. 6 is an example of the configuration in which the thermal type flow rate detecting elements 104-1 to 104-n are connected in series, and replaces the circuit of FIG. in this case,
The signal processing unit 108 includes a constant current source 181 'instead of the constant voltage source 181, and detects the voltage Vs between the output terminals of the constant current source 181'. With this circuit configuration as well, the voltage Vs having a value depending on the change in the combined resistance of the resistors r1 to rn can be obtained.

Further, in the thermal type flow rate detector shown in FIG. 7, the center of gravity of the member is changed according to its cross-sectional position in order to suppress the generation of Karman vortices that cause undesired vibration. Specifically, the thickness of the support member 102 is gradually changed to be thin at the tip portion and thick at the root portion. For the same purpose, the thermal type flow rate detector shown in FIG. 8 is one in which the width of the support member 102 is gradually changed to be narrow at the tip portion and wide at the root portion.

Furthermore, the thermal type flow rate detector shown in FIG.
Although the cross section along the axis of the pipeline is shown, the support member 1
02 is formed so that its cross section has a wedge shape. It is attached to the ball valve so that its sharp corner 111 faces upstream of the gas flow. Thereby, the pressure loss of the gas flow due to the presence of the thermal type flow rate detector can be reduced.

Further, the thermal type flow rate detector shown in FIG.
The support member 102 is formed so that its external shape is substantially streamlined. In this case, the protective cover 105 is also formed in a symmetrical streamline in order to cancel the undesired buoyancy.
The thermal type flow rate detection element 104 and the like are embedded to prevent turbulence of the flow. Thereby, the pressure loss of the gas flow due to the presence of the thermal type flow rate detector can be extremely reduced.

[0045]

As is clear from the above description, in the ball valve for gas conduit according to the first solution, it is not necessary to incorporate the flow rate detector into the ball valve and separately install it. , And by adopting a flow rate detector having a configuration capable of measuring the gas flow rate in the through hole in response to the change in the flow velocity distribution in the through hole, the installation location is not limited to the pit,
It can be installed in a direct buried type or a front and rear valve such as a governor.

Further, in the ball valve for the gas conduit according to the second solution means, the flow rate detector can be easily inserted and removed from above so that the flow rate detector can be easily maintained. did it.

Further, in the ball valve for the gas conduit of the third and fourth means, the gas flow rate can be calculated based on the total supply current or the total applied voltage, so that the gas flow rate can be easily calculated. Can also be measured.

[Brief description of drawings]

FIG. 1 is an overall view of an embodiment of a ball valve for a gas conduit according to the present invention at the time of installation.

FIG. 2 is a perspective view of the thermal type flow rate detector.

FIG. 3 is a sectional view of the same.

FIG. 4 is a plan view and a sectional view of the thermal type flow rate detecting element.

FIG. 5 is a circuit block diagram of a constant voltage drive system.

FIG. 6 is a circuit block diagram of a constant current drive system.

FIG. 7 is a modification of the thermal type flow rate detector.

FIG. 8 is a modification of the thermal type flow rate detector.

FIG. 9 is a modification of the thermal flow rate detector.

FIG. 10 is a modification of the thermal flow rate detector.

FIG. 11 is a schematic diagram illustrating a gas supply system.

FIG. 12 is a schematic view showing an installation form of a conventional regional block valve.

[Explanation of symbols]

 1 Factory 2 High-pressure conduit 3 Governor station 4 Medium-pressure conduit 5 District governor 6 Low-pressure conduit 7 Consumer 8 Central monitoring center 10 Emergency shutoff valve 11 Regional block valve 12 Pit 13 Hot tapping 14 Pressure gauge 15 Flow rate detection sensor 16, 17 Impulsive pipe 18 Signal processing unit 19 Valve 20 Valve body 21 Base 22 Valve body 23 Lower stem shaft 24 Upper stem shaft 25 Through hole 26, 27 Flange 28 Gabox 30 Geared motor 31 Handle 32 Pinion gear 33 Hollow passage 37 Attachment part 100 Thermal type Flow rate detector 102 Supporting member 103 Glass substrate 104 Thermal flow rate detecting element 105 Protective cover 106 Interval holding member 107 Temperature detecting element 108 Signal processing unit 109 Signal line 111 Sharp corner 131 Wiring pattern 132 Wiring pattern side connection pad 133 Connection terminal pad 134 Temperature detection pad 141 Silicon substrate 142 Protective film 143 Heater wire 144 Contact pad 145 Recess 146 Gold wire

Claims (4)

[Claims] 1. A valve main body inserted into a gas conduit, and a spherical valve body having a through hole for gas flow formed therein and housed in the valve main body. In a ball valve for a gas conduit for shutting off or controlling the flow rate of a gas in a gas conduit, a plurality of thermal flow rate detecting elements are provided in the through hole, and a flow rate detecting element is provided in the through hole. A ball valve for a gas conduit, characterized by detecting a physical quantity according to a gas flow rate in the through hole. 2. The valve body is supported by an upper stem shaft and a lower stem shaft installed in a valve body, and the upper stem shaft is configured to be detachable, and the thermal flow rate detecting element is attached to the upper stem shaft. The ball valve for a gas conduit according to claim 1, wherein the ball valve is configured to be connected. 3. The flow rate detecting body according to claim 1, wherein the plurality of thermal type flow rate detecting elements are connected in parallel and are driven at a constant voltage. Ball valve for the described gas conduit. 4. The flow rate detecting body according to claim 1, wherein the plurality of thermal type flow rate detecting elements are connected in series and driven by a constant current. Ball valve for the described gas conduit.