JP3710105B2 - Ball valve for gas conduit with built-in flow meter - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a ball valve used as a gas shut-off on the path of a gas supply conduit, and more specifically, a flow meter is built in the valve body, and the flow meter is configured to allow maintenance and inspection work from outside the ground. Related to the ball valve.
[0002]
[Prior art]
As shown in FIG. 1, the gas supply system is configured to send the gas (pressure = 10 kg / cm ² or more) produced in the factory 1 to the governor station 3 through the high-pressure conduit 2 and decompress the gas (pressure) = 10 kg / cm ² less than 1 kg / cm ² or higher) delivered to the district governor 5 for each consumer areas by medium-pressure tube 4 and the decompressed gas in district governor 5 (less than 1 kg / cm ²⁾ by a low-pressure conduit 6 A method of supplying to each consumer 7 is adopted.
[0003]
In this gas supply system, an emergency shut-off valve 10 for the gas sent from the factory 1 is provided in the high-pressure conduit 2 so that the supply of gas can be shut off based on a command from the central monitoring center 8 as a countermeasure for disasters such as earthquakes. In addition, a regional block valve 11 (shutoff valve) is provided in the intermediate pressure conduit 4 leading to the district governor 5 in each consumption area.
[0004]
At the location where the regional block valve 11 is installed, the gas flow rate can be measured simultaneously with the gas cutoff so that it can be managed whether or not the supply gas is stably supplied to each downstream consumption area. .
For this reason, normally, at the installation position of the regional block valve 11, as shown in FIG. 2, a hot tapping 13 is provided in the installation pit 12 along with the regional block valve 11 to extract a gas for flow rate measurement from the pipe. And a gas pressure gauge 14 are provided.
In the hot tapping 13 described above, a flow rate detection sensor 15 is suspended in the pipe of the intermediate pressure conduit 2 as can be seen in a known gas flow meter (see, for example, Japanese Patent Laid-Open No. 4-2922). The flow rate measuring means is configured so that the static pressure and the dynamic pressure of the gas obtained from the above can be led to the ground flow rate calculator 18 by the pressure guiding pipes 16 and 17 and the flow rate of the gas can be calculated from the differential pressure between them. .
[0005]
[Problems to be solved by the invention]
By the way, when detecting the flow rate of gas, in order to ensure the accuracy, the flow rate detection sensor 15 must be arranged in a straight pipe portion having the required length and the same inner diameter. Therefore, when the hot tapping 13 and pressure gauge 14 for detecting the flow rate are provided in the pit 12 for installing the above-mentioned regional block valve 11 (shutoff valve), the pit is used to secure the span of the straight pipe portion. No. 17 must be large, and the construction cost for constructing the pit is expensive.
In particular, the regional block valve 11 is installed separately in front of the district governor 5 which is separated from the governor station 3 for each consumption area, so that the number of installed block blocks will exceed several thousand (about 5000) as a whole. In addition, there is a problem that the installation cost of the regional block valve 11 becomes enormous.
[0006]
Therefore, the present inventor uses a gas shut-off valve as a ball valve, a flow rate detection sensor in the through hole of the valve body, and a flow rate calculation means for calculating a gas flow rate based on a signal obtained from the flow rate detection sensor. In addition, gas block and flow rate measurement are achieved by a single valve, thereby eliminating the need for hot tapping and pressure gauge as in the past, and reducing the size of the pit, thereby making the regional block valve Considered measures to greatly reduce the construction cost required for installation of
[0007]
In this case, since the flow rate detection sensor built in the valve body has an error due to adhesion of water vapor or tar in the gas, it is possible to perform maintenance work such as cleaning and replacement of the flow rate detection sensor from outside the ground. It is necessary to consider.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to provide a ball valve in which a flow meter built in a valve body is configured to allow maintenance and inspection work from outside the ground so as to satisfy the above-described demand.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a valve for shutting off or adjusting the flow rate of a gas provided on a pipeline of a gas conduit, the valve having a spherical valve body having a through hole having the same diameter as the inner diameter of the conduit. And a valve main body that rotatably supports and accommodates the valve body about a vertical axis, circulates gas with the through hole of the valve body positioned coaxially with the gas conduit, and the through hole extends in a direction perpendicular to the conduit. In the ball valve that is positioned to shut off the gas or adjust the flow rate, the following measures are taken.
[0010]
That is, the ball valve according to the present invention includes a flow rate detection means for measuring a gas flow rate based on a signal obtained from the flow rate detection sensor, as well as including a flow rate detection sensor for the gas passing through the hole in the through hole of the valve body. And a valve body and a valve body of the ball valve that communicate with each other in the through hole of the valve body to raise the flow rate detection sensor above the valve body, and a valve body that communicates with the passage. A hollow chamber for maintenance and inspection, and has an opening end that can be airtightly closed by an upper plate and can be opened as necessary. the flow rate detection sensor while ensuring the circulation of gas between the side and the downstream side through the passage pulled the hollow chamber, from the ground outside by opening the open end of the hollow chamber to enable the maintenance of the flow rate detector It is characterized by comprising. In addition, when the valve body is closed in an emergency such as an earthquake, it has another feature that it has means capable of closing the passage for ensuring the gas flow on the upstream side and the downstream side of the valve body. .
[0011]
[Action]
According to the ball valve having such a configuration, the gas shut-off and the flow rate measurement can be achieved by a single valve. Therefore, when this ball valve is used as a regional block valve, the conventional hot valve is used. Since tapping and pressure gauges are not required and the pit installation space can be reduced, the pit can be reduced in size and the construction cost required for installing the regional block valve can be reduced.
[0012]
If water vapor or tar in the gas adheres to the flow rate detection sensor built in the valve body, the flow rate detection body is pulled up into the hollow chamber through the pull-up passage, and the hollow chamber is opened from outside the ground to open the flow rate. Since the maintenance and inspection of the detection sensor is possible, maintenance work such as cleaning and replacement of the flow meter can be performed easily.
[0013]
The pull-up passage formed in the valve body and the valve body is formed above the valve main body so as to communicate with the through hole of the valve body. Is not ejected, and the flow rate detection sensor can be pulled up from the through hole without stopping the supply of gas.
[0014]
【Example】
An embodiment of the present invention will be described below with reference to the drawings.
FIG. 3 shows a ball valve according to the present invention which is used in place of the above-mentioned regional block valve 11, and the valve is located between the upstream intermediate pressure conduit 4 a and the downstream intermediate pressure conduit 4 b traversing the inside of the pit 12. A main body 20 is interposed. The valve body 20 is supported on the bottom of the pit 12 via the base 21 and is interposed so as to communicate the upstream side and the downstream side of the intermediate pressure conduits 4a and 4b.
[0015]
A spherical valve body 22 is housed inside the valve main body 20 as seen in a normal ball valve, and the upper and lower sides of the valve body 22 are interposed between an upper stem shaft 24 and a lower stem shaft 23. The valve body 20 is rotatably supported.
The valve body 22 is provided with a through hole 25 having the same diameter as the inner diameters of the intermediate pressure conduits 4a and 4b connected to the valve body 20, and a straight pipe for disposing a flow rate detecting body 34 to be described later. The span of the part can be shared by the valve body 22. Further, as shown in the figure, the valve body 22 is in the open position when the through hole 25 is positioned in the same direction as the axis of the intermediate pressure conduits 4a and 4b, and the through hole 25 extends to the axis of the intermediate pressure conduits 4a and 4b. On the other hand, when the valve is positioned at a right angle, the valve is closed.
[0016]
A gear box 28 is connected to the upper portion of the valve body 20 via flanges 26 and 27, and a worm gear (not shown) is rotated into the gear box 28 by a rotation operation of a geared motor 30 or a handle 31 attached to the gear box 28. The valve element 22 is rotationally driven by the geared motor 30 or the handle 31 by meshing with the pinion gear 32 fixed to the upper stem shaft 24 that is plunged and supported.
[0017]
The upper stem shaft 24 is formed as a hollow shaft, and a hollow passage 33 is formed in the shaft core. A pipe 35 having a flow rate detection body 34 at the lower end is inserted into the hollow passage 33, and the flow rate detection body 34 is suspended in the through hole 25 of the valve body 22 and flows through the through hole 25. To come in contact with.
Further, a hollow chamber 36 for maintenance and inspection is communicated with the hollow passage 33. The hollow chamber 36 is connected to the gear box 28 and has a vertically long opening end located in the pit 12 near the ground. It is. The opening end is airtightly closed with an upper plate integrated with a signal conversion unit 37 that detects and measures a signal obtained from the flow rate detector 34, and can be opened as necessary.
[0018]
The signal converter 37 converts a physical signal (for example, a pressure signal) from the flow rate detector 34 into an electrical signal, and is connected to a flow rate calculator 42 installed on the ground via a signal line 40. Here, the flow rate calculator 42 constitutes a flow rate measuring means for calculating the gas flow rate based on the electrical signal from the signal conversion unit 37.
[0019]
When the valve body 22 is in the closed position, the inside of the through hole 25 is closed so that both ends thereof are in contact with the inner surface of the valve body 20, and the hollow passage 33 is also cut off from the gas pressure. Therefore, when the valve body 22 is in the closed state, no gas is ejected through the hollow passage 33. Therefore, the valve body 22 is closed, the upper plate of the hollow chamber 36 is opened to open the hollow chamber 36, and the flow rate detection body 34 is pulled upward in the hollow chamber 36 through the hollow passage 33 and attached to the flow rate detection body 34. It is possible to adopt a configuration in which maintenance work such as removal of water vapor and tar content in the gas is performed from outside the ground.
[0020]
The valve body 22 has a required gap with respect to the inner peripheral surface of the valve body 20 that accommodates the valve body 22, and the intermediate pressure conduit 2a on the upstream side and the downstream side are also closed when the valve is closed via the gap portion 20a. If the gas flow with the intermediate pressure conduit 2b is ensured, the maintenance work of the flow rate detector 34 can be performed without causing any trouble in the downstream gas supply.
[0021]
In the event of a disaster such as an earthquake, when the gas supply is shut off based on a command from the central monitoring center 8, the valve body 22 is rotated to the closed position by the geared motor 30. The ring shutters 43 and 44 provided at the connecting portion between the main body 20 and the intermediate pressure conduits 2a and 2b on the upstream side and the downstream side are also interlocked at the same time so that the communication by the gap 20a can be closed.
[0022]
Next, an example in which the flow rate measuring means attached to the ball valve is configured as a differential pressure type flow meter and an example configured as an electric type flow meter will be described with reference to the drawings.
FIG. 4 shows an example in which a conventionally known average value pitot tube 60 is adopted, which is constructed in a differential pressure type. The average value pitot tube 60 includes a dynamic pressure pitot 62 having a large number of holes and a static pressure. The pitot 61 forms a double pipe, and the dynamic pressure line 51 is connected to the inside of the dynamic pressure pitot 62, and the static pressure line 52 is connected to the inside of the static pressure pitot 61, and the difference between the dynamic pressure and the static pressure. The gas flow rate is measured from the pressure.
[0023]
Further, a configuration using an electric example instead of the above-described differential pressure type example will be specifically described with reference to FIGS. 5 and 6.
FIG. 5 is an explanatory diagram showing the configuration of a flow sensor (thermal type). The flow sensor measures the flow rate of the gas based on the temperature difference and detects the flow rate of the gas based on the result.
As shown in FIG. 5A, a first thermistor 71, a heater 72, and a second thermistor 73 are disposed on a planar center chip 70. The center chip 70 configured as described above is arranged in the center of the flow sensor 74 and installed inside the ball valve, as shown in FIG. When the gas flows in the direction of the arrow in the figure, the temperature at the second thermistor 73 on the downstream side of the heater 72 becomes higher than the temperature at the first thermistor 71 on the upstream side of the heater 72, and from this temperature difference The gas flow velocity is measured.
[0024]
FIG. 6 is an explanatory diagram showing the configuration of the Karman vortex sensor, in which a vortex generator 80 is disposed inside the ball valve. Then, as shown in the figure, when a gas flows in the direction of the arrow in the figure, a Karman vortex street is generated downstream of the vortex generator 80, and the gas flow rate is detected by measuring the frequency of the Karman vortex street. To do.
[0025]
When the electrical sensor described with reference to FIGS. 5 and 6 is used, the static pressure line and the dynamic pressure line necessary for the differential pressure type flow meter are not required, and the static pressure line and the dynamic pressure line are not affected by an impact caused by an earthquake or the like. The fear of gas leaks due to breakage is eliminated.
[0026]
【The invention's effect】
According to the present invention, as described above, the gas shutoff valve provided in the gas supply conduit is configured as a ball valve, and the ball valve includes a flow rate detection sensor suspended in the through hole of the valve body, and The flow rate calculation means for calculating the gas flow rate based on the signal obtained from the flow rate detection sensor is provided, so that the gas shutoff and the flow rate measurement can be achieved by a single valve. For example, when used as a regional block valve in a conventional gas supply system, there is no need to install a hot tapping or pressure gauge as in the past, and the pit where the ball valve is installed is much smaller and smaller than before. The construction cost required to install the regional block valve can be greatly reduced.
[0027]
If water vapor or tar content in the gas adheres to the flow rate detector built in the valve body, the flow rate sensor is pulled up through the pull-up passage into the hollow chamber, and the hollow chamber is opened from outside the ground to open the flow rate. Since maintenance and inspection of the detector is possible, maintenance work such as cleaning and replacement of the flowmeter can be easily performed.
[0028]
The pull-up passage formed in the valve body and the valve main body is formed above the valve main body so as to communicate with the through hole of the valve body. Therefore, the gas from the pull-up passage and the hollow chamber can be obtained only by bringing the valve body to the closed position. The pressure can be prevented from being ejected, and the flow rate detection body can be pulled up from the through-hole without stopping the gas supply, and the maintenance work can be performed.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a gas supply system. FIG. 2 is a schematic diagram illustrating a conventional regional block valve installation configuration. FIG. 3 is a longitudinal sectional view of a ball valve according to the present invention. Cross-sectional view of a flow rate detector using a liquid [Fig. 5] Explanatory drawing of a flow sensor [Fig. 6] Explanatory drawing of a Karman vortex sensor [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 shut-off valve 11 Regional block valve 12 Pit 13 Hot tapping 14 Pressure gauge 15 Flow detection sensors 16, 17 18 Flow calculator 19 Valve 20 Valve body 20a Gap 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 34 Flow rate detector 35 Pipe line 36 Hollow chamber 37 Signal converter 40 Signal line 42 Flow rate calculators 43 and 44 Ring shutter 51 Dynamic pressure line 52 Static pressure line 60 Average value Pitot pipe 61 Static pressure Pitot 62 Dynamic pressure Pitot 70 Center chip 71 First thermistor 72 heater 73 second thermistor 74 flow Sir 80 vortex generator

Claims (2)

A valve provided on the pipeline of a gas conduit to cut off or adjust the flow rate of the gas, the valve having a spherical valve body having a through-hole having the same diameter as the inner diameter of the conduit, and rotating the valve body about a vertical axis A ball that consists of a valve body that is freely supported and accommodated, and in which the through hole of the valve body is positioned coaxially with the gas conduit to circulate the gas, and the through hole is positioned in a direction perpendicular to the conduit to block the gas or adjust the flow rate. In what became the valve,
The ball valve includes a flow rate detection sensor for gas passing through the hole in the through hole of the valve body, and flow rate calculation means for measuring the gas flow rate based on a signal obtained from the flow rate detection sensor. In addition, the valve body and the valve body of the ball valve have a passage communicating with the inside of the through hole of the valve body and pulling up the flow rate detection sensor above the valve body, and communicating with the passage at the upper part of the valve body. A hollow chamber for maintenance and inspection,
The hollow chamber has an opening end that can be airtightly closed with an upper plate and can be opened as necessary.
During valve closing and opening the upstream-side and downstream side of the through passage flow rate detection sensor while securing the flow of gas raised to the hollow chamber, from the ground outside of the hollow chamber open end of the valve body flow A ball valve for a gas conduit with a built-in flow meter, characterized in that the detector can be maintained and inspected.   2. A flow meter according to claim 1, further comprising means for closing a passage for ensuring gas flow upstream and downstream of the valve body when the valve body is closed in an emergency such as an earthquake. Ball valve for gas conduit with built-in.

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