JP2011180055A - Ultrasonic-wave gas meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic-wave gas meter which does not perform erroneous measurements, even when the water content infiltrates the gas meter. <P>SOLUTION: The ultrasonic-wave gas meter is provided with an ultrasonic-wave transceiver 5 on the power side of a measurement tube 4, as well as, a resistance-value detecting means 11 for detecting the resistance between terminals 10a-10b of the ultrasonic-wave transceiver 5. When a predetermined resistance value is detected by the resistance-value detecting means 11, by determining that the water content has infiltrated a gas meter 1, a shut-off valve 3 is closed to thereby shut off the gas and prevent continuance of wrong measurements. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to the structure of an ultrasonic gas meter.

  As a gas meter using an ultrasonic transmitter / receiver, the gas meter has a gas flow path through which gas passes from top to bottom, in the horizontal direction, and from bottom to top. It is known that the flow path is a measurement flow path that measures the flow rate of the gas in the horizontal direction, and the exit path is the flow path from the bottom to the top (see, for example, Patent Document 1).

  A conventional ultrasonic gas meter will be described below.

  As shown in FIG. 3, the ultrasonic gas meter described in Patent Document 1 is provided with a shutoff valve 103 for opening and closing the gas in the inlet-side passage 102 of the gas meter 101, and the measurement channel in the horizontal direction. The measurement tube 104 is disposed, and a pair of ultrasonic transmitters / receivers 105 are disposed on the side surface of the measurement tube 104 so as to face each other. Further, an outlet side passage 106 is disposed following the measuring tube 104, and a gas meter is constituted by a substantially U-shaped flow path member 107 as a whole.

  The operation of the gas meter configured as described above will be described.

  In a normal state where there is no danger in using the gas, the shutoff valve 103 is in a return (opened) state, and gas can be supplied to a gas appliance (not shown) downstream of the gas meter 101. When gas is used in the gas appliance, the amount of gas flowing through the measurement tube 104 is measured by the measurement tube 104.

  A pair of ultrasonic transmitter / receiver 5 is attached to the measurement tube 104, and when the ultrasonic wave is propagated to the gas flowing through the measurement tube 104, the propagation time or propagation speed of the ultrasonic wave changes depending on the gas flow velocity. This is used to measure the gas flow rate.

JP 2004-333202 A

  However, in the conventional ultrasonic gas meter, when water in the gas pipe enters the gas meter 101, the water storage unit 8 for storing water has a small capacity as shown in FIG. Intrusion into the tube 104 will occur. And if moisture enters the measuring tube 104, the propagation time of the ultrasonic wave is different, or the gas flow rate cannot be accurately measured because the cross-sectional area where the gas actually flows in the flow channel tube becomes small, and incorrect measurement is performed. There was a problem of continuing.

  Further, in order to make it difficult for moisture to enter the measuring tube, there is a method of enlarging the water storage section 108 ′ as shown in FIG. 4, but in that case, there is a problem that the housing of the gas meter 101 ′ becomes too large. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an ultrasonic gas meter that does not continue wrong measurement even when moisture enters the gas meter without increasing the size of the gas meter housing.

  In order to solve the above-described conventional problems, a fluid shutoff device according to the present invention is provided in the vicinity of an inlet of a channel member having an inlet and an outlet and formed in a substantially U-shaped cylindrical shape. A shut-off valve that opens and closes the gas; a measurement pipe that is provided horizontally near the bottom surface of the flow path member; a pair of ultrasonic transceivers provided on the upstream side and the downstream side of the measurement pipe; Flow rate calculating means for calculating the flow rate of the gas flowing in the measurement tube from the propagation time of the ultrasonic wave between the ultrasonic transmitter / receiver, and at least one of the pair of ultrasonic transmitter / receivers is arranged below the measurement tube. And having resistance value detection means for measuring resistance between terminals of the ultrasonic transmitter / receiver disposed below the measurement tube, and when the resistance value detection means detects a predetermined resistance value, The shut-off valve is closed.

  Thereby, one or both of a pair of ultrasonic transmitter / receivers are arranged below the measuring tube, and by detecting the resistance between terminals of the ultrasonic transmitter / receiver, it is detected that moisture has entered the gas meter. Can do.

  According to the ultrasonic gas meter of the present invention, even when moisture enters the gas meter, the gas flow rate measurement can be stopped immediately, and incorrect measurement can be prevented from being continued.

Sectional drawing of the ultrasonic type gas meter of Embodiment 1 of this invention Sectional drawing of the ultrasonic type gas meter of Embodiment 2 of this invention Cross-sectional view of a conventional ultrasonic gas meter Cross-sectional view of a conventional ultrasonic gas meter

  The first invention includes a flow path member having an inlet and an outlet and formed in a substantially U-shaped cylindrical shape, a shut-off valve installed near the inlet of the flow path member to open and close the gas, and the flow path From a measurement tube provided close to the bottom surface of the member and provided horizontally, a pair of ultrasonic transmitters / receivers provided on the upstream side and the downstream side of the measurement tube, and an ultrasonic wave propagation time between the pair of ultrasonic transmitters / receivers A flow rate calculating means for calculating a flow rate of the gas flowing in the measurement tube, and at least one of the pair of ultrasonic transceivers is disposed below the measurement tube and disposed below the measurement tube. A resistance value detecting means for measuring the resistance between the terminals of the installed ultrasonic transmitter / receiver, and when the resistance value detecting means detects a predetermined resistance value, the shut-off valve is closed; It was possible to detect that water had entered the gas meter before water entered. , It is possible to prevent the metering wrong gas flow rate.

  A second invention has a drain valve for discharging water stored in the gas meter at the bottom of the gas meter in the first invention, and closes the shut-off valve when the resistance value detecting means detects a predetermined resistance value. After the operation, the drain valve is opened for a predetermined time to drain the water stored in the gas meter, and the shut-off valve is further opened to restart the gas flow measurement. Water enters the gas meter. As soon as it is detected, the moisture is discharged out of the gas meter, so that the moisture does not enter the measuring tube and the gas flow rate can be accurately measured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a sectional view of an ultrasonic gas meter according to Embodiment 1 of the present invention.

  In FIG. 1, a valve seat 7c is provided in the middle of the inlet-side passage 2 from the upper side to the lower side of the flow path member 7 formed in a substantially U-shaped cylindrical shape, and has a valve 3a for opening and closing the valve seat 7c. A solenoid type or PM type stepping motor type shutoff valve 3 is disposed. A measuring pipe 4 for measuring a gas flow rate is disposed in a horizontal part below the inlet side passage 2 of the flow path member 7. The measurement tube 4 is provided with a pair of ultrasonic transmitters / receivers 5 on the upstream side and the downstream side of the measurement tube 4 so as to measure the gas flow rate by changing the propagation time or propagation speed of the ultrasonic waves. And the exit channel | path 6 which discharges | emits the gas which flowed out from the measurement pipe | tube 4 out of the gas meter 1 from the downward direction of the substantially U-shaped flow-path member 7 to upper direction is comprised.

  The partition 7b partitions the inlet-side passage 2 and the outlet passage 6 when the measuring tube 4 is positioned above the bottom portion 7a of the road member 7 in order to secure an arrangement space for the ultrasonic transmitter / receiver 5. By this partition 7b, all the gas flowing in from the inlet side passage 2 passes through the measuring pipe 4 and is discharged from the outlet passage 6 to the outside of the meter.

  A pair of ultrasonic transmitters / receivers 5 is provided below the measuring tube 4 on the upstream side and the downstream side, and the terminals 5a to 5d of the ultrasonic transmitter / receiver 5 and the controller 9 are connected by lead wires 10a to 10d. ing. The controller 9 has resistance value detection means 11 for measuring the resistance between the terminals of the ultrasonic transceiver 5 (5a and 5b and / or 5c and 5d), and measures the resistance between the terminals of the ultrasonic transceiver 5 can do.

  The controller 9 calculates the gas flow rate based on the ultrasonic propagation time between the ultrasonic transceivers 5 and measures the gas pressure in the gas meter based on a signal from a pressure sensor (not shown). It has a function of opening and closing the shut-off valve 3 according to the situation.

  The operation of the ultrasonic gas meter configured as described above will be described.

  Normally, in a state where moisture does not enter the gas meter 1, the terminals (5a to 5d) of the ultrasonic transmitter / receiver 5 are in a gas atmosphere, so the resistance between the terminals of the ultrasonic transmitter / receiver 5 is infinite. Show.

  On the other hand, when water enters the gas meter 1, the water gradually accumulates in the water storage unit 8, and when the terminals 5 a and 5 b of the ultrasonic transmitter / receiver 5 are both submerged, the resistance between the terminals of the ultrasonic transmitter / receiver 5 becomes water. The resistance detection means 11 detects this resistance value, and the controller 9 determines that water has accumulated in the water storage section 8. I can do it.

  At this time, the controller 9 closes the shut-off valve 3 and shuts off the gas, so that moisture does not enter the measuring tube and can prevent wrong measurement.

  As described above, the ultrasonic gas meter according to the first embodiment of the present invention can detect that moisture has entered the gas meter 1 by measuring the resistance between the terminals of the ultrasonic transmitter / receiver 5 and close the shutoff valve 3. Since it is operated, it is possible to prevent the wrong measurement from being continued with water in the measuring tube 4.

  In the present embodiment, the case where water has accumulated at the bottom on the inlet side has been described, but it is needless to say that the outlet side can be similarly configured.

(Embodiment 2)
FIG. 2 is a cross-sectional view of an ultrasonic gas meter according to Embodiment 2 of the present invention.

  In FIG. 2, the bottom 7a of the gas meter 1 is provided with a drain port 7d for discharging water stored in the gas meter 1, and a drain valve 12 having a valve 12a for opening and closing the drain port 7d is disposed. The controller 9 is connected to the lead wires 13a and 13b.

  Other parts are the same as those of the ultrasonic gas meter of FIG.

  The operation of the ultrasonic gas meter configured as described above will be described.

  When moisture does not enter the gas meter 1, it is the same as in the first embodiment, and a description thereof is omitted.

  When moisture enters the gas meter 1, water gradually accumulates in the water storage unit 8, and when the terminals 5 a and 5 b of the ultrasonic transceiver 5 are submerged, the resistance between the terminals of the ultrasonic transceiver 5 is the resistance value of water. The resistance detection means 11 detects this resistance value, and the controller 9 may determine that water has accumulated in the water storage unit 8. it can.

  At this time, the controller 9 first shuts off the gas by closing the shutoff valve 3. Thereafter, the drain valve 12 is opened and the drain port 7d is kept open for a predetermined time to drain the water accumulated in the gas meter 1, and then the drain valve 12 is closed, and the valve 12a opens the drain port. Close. Thereafter, the shut-off valve 3 is opened.

  That is, even if water accumulates in the gas meter 1, it can be drained out of the gas meter 1 before the water enters the measuring tube 4 and the measurement of the gas flow rate can be resumed. The timing for closing the drain valve 12 may be the time when the resistance detecting means 11 detects that the resistance between the terminals 5a and 5b of the ultrasonic transceiver 5 has become infinite.

  As described above, the ultrasonic gas meter according to Embodiment 2 of the present invention discharges moisture outside the gas meter 1 before moisture enters the measurement tube 4 even if moisture enters the gas meter 1. You can eliminate wrong weighing.

  In the present embodiment, the case where water has accumulated at the bottom on the inlet side has been described, but it is needless to say that the outlet side can be similarly configured.

  As described above, since the ultrasonic gas meter according to the present invention can detect that moisture has entered the gas meter, it can be applied to any ultrasonic gas meter.

DESCRIPTION OF SYMBOLS 1 Gas meter 3 Shut-off valve 4 Measuring tube 5 Ultrasonic transmitter / receiver 5a-5d Terminal 7 Flow path member 7a Bottom part 9 Controller (flow rate calculation means)
11 Resistance detection means 12 Drain valve

Claims (2)

A channel member having an inlet and an outlet and formed in a substantially U-shaped cylindrical shape, a shut-off valve installed near the inlet of the channel member for opening and closing a gas, and a bottom surface of the channel member A gas flowing in the measurement tube from a horizontal measurement tube, a pair of ultrasonic transmitters / receivers provided upstream and downstream of the measurement tube, and an ultrasonic wave propagation time between the pair of ultrasonic transmitters / receivers And at least one of the pair of ultrasonic transmitters / receivers is disposed below the measurement tube and the ultrasonic transmission / reception disposed below the measurement tube. An ultrasonic gas meter having resistance value detecting means for measuring resistance between terminals of the vessel, and closing the shutoff valve when the resistance value detecting means detects a predetermined resistance value. A drain valve for discharging water stored in the gas meter is provided at the bottom of the gas meter, and when the resistance value detecting means detects a predetermined resistance value, the shut-off valve is closed and then the drain valve is opened for a predetermined time. The ultrasonic gas meter according to claim 1, wherein after the water stored in the gas meter is drained, the shutoff valve is further opened to restart the gas flow rate measurement.