JP4282836B2 - Gas meter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas meter that measures and integrates gas flow rates.
[0002]
[Prior art]
Conventionally, a gas meter that measures and integrates the flow rate of gas supplied from an upstream side (for example, a gas company) to a downstream side (for example, a gas customer) has one flow path with a defined flow range, The flow rate of the gas flowing through the flow path is detected by a flow rate sensor, and the flow rate of the gas is measured based on the detection signal and integrated.
[0003]
[Problems to be solved by the invention]
However, since the conventional gas meter has only one flow path with a predetermined flow rate range, it is necessary to change the gas equipment of the gas consumer and to supply a gas with a large flow rate. The gas meter must be replaced. That is, there is a problem that a conventional gas meter cannot cope with a wide range of gas flow rates.
[0004]
Therefore, in the present invention, for example, it is an object to be solved to provide a gas meter that can cope with even when a gas appliance of a gas consumer is changed and a large flow rate of gas needs to be supplied. It is.
[0005]
[Means for Solving the Problems]
The above problems can be solved by the gas meter described in the appended claims.
According to the gas meter of the first aspect, the flow path corresponding to the flow rate of the gas flowing from the gas inlet to the gas outlet is selected from a plurality of flow paths, the selected flow path is opened by driving the on-off valve, and the gas is discharged. Since it can be made to flow, the gas flow rate measurement range can be widened. Therefore, even when a gas consumer's gas equipment is changed and it becomes necessary to supply a gas with a large flow rate, it is possible to cope with one unit.
[0006]
According to the gas meter of the second aspect, it is possible to automatically select a flow path through which the gas flows in accordance with the gas pressure that changes corresponding to the flow rate of the gas flowing from the gas inlet to the gas outlet.
[0007]
According to the gas meter of the third aspect of the present invention, the gas meter is set in advance corresponding to the detection signal of one flow sensor arranged in one flow path for flowing the gas in the minimum flow range and the flow characteristics of each flow path. The flow rate of the gas flowing from the gas inlet to the gas outlet can be measured and integrated based on the coefficient. Therefore, the flow rate of the gas flowing through the plurality of flow paths can be measured with one flow rate sensor.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described.
FIG. 1 is a cross-sectional view showing the configuration of the gas meter 1. As shown in FIG. 1, the gas meter 1 has a case 2 provided with a gas inlet 3 to which a pipe of a gas company or the like is connected, and a gas outlet 4 to which a pipe of a gas consumer or the like is connected.
Inside the case 2, a front chamber 5 communicating with the gas inlet 3 and a rear chamber 6 communicating with the gas outlet 4 are formed. Further, a first flow path 7 and a second flow path 8 are formed between the front chamber 5 and the rear chamber 6. The first flow path 7 is a flow path for flowing gas in a normal flow rate range, and the second flow path 8 is a flow path for flowing gas having a flow rate exceeding the upper limit of the flow rate range of the first flow path 7.
[0009]
In the front chamber 5, a first valve body 9 that opens and closes the first flow path 7 and a second valve body 10 that opens and closes the second flow path 8 are provided. Further, a valve driving device 11 that integrally drives the first valve body 9 and the second valve body 10 is attached to the outside of the case 2. This valve drive device 11 has a drive mechanism that converts the rotation of the motor into a linear motion, and is configured such that the rod 11a is moved in the axial direction by the rotation of the motor.
A plate-shaped valve seat 12 is attached to the distal end portion of the rod 11 a, and the base end portions of the two valve shafts 13 and 14 are fixed to the valve seat 12. These valve shafts 13, 14 are formed in a cylindrical shape with an open end, and a shaft (not shown) of the first valve body 9 is slidably inserted into the inner diameter portion of the valve shaft 13, A shaft (not shown) of the second valve body 10 is slidably inserted into the inner diameter portion of the valve shaft 14.
A base end portion of a spring 15 disposed on the outer peripheral portion of the valve shaft 13 is elastically attached to the valve seat 12, and a distal end portion is elastically attached to the first valve body 9. Further, the base end portion of the spring 16 disposed on the outer peripheral portion of the valve shaft 14 is elastically attached to the valve seat 12, and the distal end portion is elastically attached to the second valve body 10.
With this configuration, when the first valve body 9 and the second valve body 10 are driven to positions that close the first flow path 7 and the second flow path 8, respectively, the elastic force of the springs 15 and 16 Since the first valve body 9 and the second valve body 10 are pressed, the flow paths 7 and 8 are reliably closed.
[0010]
As described above, the valve drive mechanism including the first valve body 9, the second valve body 10, the valve drive device 11, the valve seat 12, the valve shafts 13 and 14, and the springs 15 and 16 is shown in FIG. As shown in (1), the first valve body 9 opens the first flow path 7 and the second valve body 10 opens the second flow path 8 (a), and the first valve The valve position in which the body 9 opens the first flow path 7 and the second valve body 10 closes the second flow path 8 (A), and the first valve body 9 is the first flow path 7. Is closed, and the second valve body 10 is positioned at the valve position (c) where the second flow path 8 is closed.
[0011]
As shown in FIG. 1, a pressure sensor 17 that detects the pressure of the gas supplied from the gas inlet to the front chamber 5 is attached to the front chamber 5. A flow rate sensor 18 that detects the flow rate of gas is attached to the first flow path 7.
The pressure sensor 17 is a known sensor using, for example, a polymer piezoelectric film, and outputs a signal corresponding to the gas pressure. The flow sensor 18 is, for example, a fluidic type or a thermal type, and outputs a signal corresponding to the gas flow rate.
The pressure sensor 17 and the flow sensor 18 are not limited to those described above, and may be any sensor that can detect the gas pressure and the gas flow rate.
[0012]
FIG. 5 is a block diagram showing an electrical configuration of the gas meter 1.
As shown in FIG. 5, the gas meter 1 includes a microcomputer 20 for controlling the valve driving device 11. The pressure sensor 17 and the flow rate sensor 18 are connected to the input side of the microcomputer 20, and the valve drive device 11 and a display 21 for displaying a gas integrated flow rate described later are connected to the output side of the microcomputer 20. Has been.
[0013]
Next, the gas measurement action of the gas meter 1 will be described.
When the gas main valve of the gas consumer is opened, gas flows into the front chamber 5.
The microcomputer 20 first sets the first valve body 9 to the valve position (a) where the first valve body 9 opens the first flow path 7 and the second valve body 10 closes the second flow path 8. The valve driving device 11 is controlled so that the valve body 9 and the second valve body 10 are positioned.
The microcomputer 20 is provided in the first flow path 7 when the magnitude of the gas pressure based on the pressure detection signal output from the pressure sensor 17 does not reach a predetermined value (point a in FIG. 2) in the above state. Based on the flow rate detection signal from the flow rate sensor 18, the flow rate of the gas is measured as will be described later, the flow rate is integrated, and the integrated flow rate is displayed on the display 21.
[0014]
Next, the microcomputer 20 increases the flow rate of the gas flowing through the first flow path 7 as shown in FIG. 2, and the magnitude of the gas pressure based on the pressure detection signal from the pressure sensor 17 reaches point a. Then, the valve driving device 11 is controlled so that the first valve body 9 and the second valve body 10 are positioned at the valve position (a) that opens the first flow path 7 and the second flow path 8. To do.
As described above, at the moment when the second flow path 8 is opened, the magnitude of the gas pressure rapidly decreases from the point a, but the microcomputer 20 ignores the change in the gas pressure within a predetermined time. Thus, the opening of the first flow path 7 and the second flow path 8 is continued.
[0015]
As described above, when both the first flow path 7 and the second flow path 8 are opened, and the gas flows into the first flow path 7 and the second flow path 8, the microcomputer 20 will be described later. Based on the flow rate detection signal from the flow rate sensor 18, the flow rate of the gas flowing in the first flow path 7 and the second flow path 8 is measured, and the flow rate is integrated and the integrated flow rate is displayed on the display 21. . When the flow rate of the gas supplied to the gas consumer decreases and the gas pressure decreases to a predetermined point b, the valve driving device 11 is controlled, and the first valve body 9 and the second valve body 10 are controlled. Is positioned at the valve position (a) to close the second flow path 8.
[0016]
FIG. 3 is a flowchart of gas flow rate measurement and flow rate integration by the microcomputer 20.
The microcomputer 20 first sets the first valve body 9 to the valve position (a) where the first valve body 9 opens the first flow path 7 and the second valve body 10 closes the second flow path 8. The valve body 9 and the second valve body 10 are positioned. In this state, the actual flow rate of the gas flowing into the first flow path 7 is determined using a coefficient β set in advance based on the flow rate detection signal from the flow sensor 18 and the flow path characteristics of the first flow path 7. After calculating and measuring, the integrated value of the flow rate is displayed on the display 21.
In addition, when the first valve body 9 and the second valve body 10 are positioned at the valve position (a) where both the first flow path 7 and the second flow path 8 are opened, the flow sensor 18 The gas flowing in the first flow path 7 and the second flow path 8 using a coefficient α set in advance based on the flow rate detection signal and the flow path characteristics of the first flow path 7 and the second flow path 8. The actual flow rate is calculated and measured, and the integrated value of the flow rate is displayed on the display 21.
When the first valve body 9 and the second valve body 10 are positioned at the valve position (C) where both the first flow path 7 and the second flow path 8 are closed, the gas flow rate is zero. Therefore, the flow rate is not integrated.
[0017]
FIG. 4 is a flowchart of safety logic for detecting an abnormality when an abnormal flow rate of gas flows or when a gas leak occurs.
As shown in FIG. 4, when the first valve body 9 and the second valve body 10 are positioned at the valve position (a) where both the first flow path 7 and the second flow path 8 are opened. , And the first valve body 9 opens the first flow path 7 and the second valve body 10 closes the second flow path 8. When the second valve body 10 is positioned, if a gas exceeding a preset upper limit flow rate flows for safety, the abnormal flow rate is detected by the flow rate sensor 18. To detect abnormal flow.
[0018]
Further, gas leakage occurs when the first valve body 9 and the second valve body 10 are positioned at the valve position (c) where both the first flow path 7 and the second flow path 8 are closed. Then, since the gas pressure detected by the pressure sensor 17 falls below a preset value for safety, the microcomputer 20 activates the safety logic to detect pressure abnormality.
[0019]
In the embodiment described above, whether the second flow path 8 is closed or opened is automatically controlled based on the pressure detection by the pressure sensor 17, but the gas supplied to the gas use equipment of the gas consumer, etc. When the flow rate range is clear, the flow channel to be opened may be selected and set in advance by manual flow channel selection means (not shown). In this case, for example, even when a gas device of a gas consumer is changed and a large flow rate of gas needs to be supplied, it is possible to deal with one unit.
Moreover, although the flow sensor 18 was provided in the 1st flow path 7, you may provide a flow sensor in each flow path.
Also, in the present embodiment, an example in which a two flow paths may be provided with three or more flow paths.
[0020]
【The invention's effect】
According to the present invention, it is possible to measure and integrate a wide range of gas flow rates with a single gas meter.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a gas meter.
FIG. 2 is an operation explanatory diagram showing a relationship between a gas flow rate and a gas pressure of a gas meter.
FIG. 3 is a flowchart showing the gas flow rate measuring operation of the gas meter.
FIG. 4 is a flowchart when an abnormality occurs.
FIG. 5 is a block diagram showing an electrical configuration of the gas meter.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas meter 2 Case 3 Gas inlet 4 Gas outlet 5 Front chamber 6 Rear chamber 7 1st flow path 8 2nd flow path 9 1st valve body 10 2nd valve body 11 Valve drive device 12 Valve seat 17 Pressure sensor 18 Flow sensor

Claims (3)

A gas meter that measures and integrates the flow rate of gas flowing from a gas inlet to a gas outlet,
A plurality of flow paths through which the gas flows in a predetermined flow rate range, and each of the plurality of flow paths is opened and closed, and the opening and closing directions are the same while opening and closing each of the flow paths in stages. An on- off valve arranged in parallel so that the flow path selection means selects from the plurality of flow paths a flow path corresponding to the flow rate of the gas flowing from the gas inlet to the gas outlet, and the on-off valve And a valve driving means for opening and closing the flow path selected by the flow path selection means by opening and closing the open / close valve in a stepwise manner by moving each of them in the same direction stepwise. Gas meter.   The gas meter according to claim 1, wherein the flow path selection unit includes a pressure sensor that detects a pressure of the gas flowing in from the gas inlet, and selects a flow path through which the gas flows based on a detection signal of the pressure sensor.   A flow sensor is disposed in one flow path for flowing the gas in the minimum flow range, and the gas is based on a detection signal of the flow sensor and a coefficient set in advance corresponding to the flow path characteristics of each flow path. The gas meter according to claim 1, further comprising means for measuring and integrating the flow rate of the gas flowing from the inlet to the gas outlet.

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