JP2012002515A - Gas shutoff device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas shutoff device that improves safety and convenience in using gas.SOLUTION: The gas shutoff device includes an amplifying unit 15 for receiving an ultrasonic signal detected by an ultrasonic transducer 31 and amplifying it to a prescribed level; a transmission/reception switching unit 14 for alternately connecting a transmission unit 13 and the amplifying unit 15 to the ultrasonic transducers 31 and 32; an amplification comparison unit 17 for comparing and determining amplification factors detected by the amplifying unit 15; a transmission time detection unit 16 for detecting a transmission time period from the ultrasonic signal amplified by the amplifying unit 15; a flow rate calculation unit 18 for converting the obtained transmission time period into a flow rate; and an abnormality determination unit 19 for determining whether a difference in the amplification factors obtained by the amplification comparison unit 17 is not less than a prescribed value, when a current within a prescribed range continues for a prescribed time period or more.

Description

  The present invention relates to a gas shut-off device that improves safety in use of gas and improves convenience in use of gas when using gas after a gas meter.

  When using gas appliances, in order to prevent accidents caused by forgetting to turn off gas or leaking gas, etc., the gas business operator managing the gas user's home and the gas supply path should notify the Systems that block supply paths are becoming widespread. As a conventional gas security device, based on the gas flow rate, etc., the gas supply is cut off when a large flow rate flows, or the gas flow is cut off when the gas flows for a long time at a minute flow rate. What shuts off when gas flows for a predetermined time is used (for example, refer to Patent Document 1).

  In a gas user's house or the like, a gas meter for measuring a gas flow rate is installed at an inlet portion of a gas supply path. Conventionally, as this type of gas meter, a membrane-type gas meter that integrates the amount of gas that flows at a predetermined flow rate is generally used, but recently, an instantaneous flow rate is obtained using an ultrasonic signal, and this instantaneous flow rate is calculated. There has also been proposed an ultrasonic gas meter that measures the flow rate of gas by integrating.

JP 2000-193506 A

  However, in the conventional gas shut-off device, when a circuit malfunction occurs due to moisture adhering to the measurement circuit or the like, an event may occur in which there is a flow rate even though the gas is not used, even if the gas is not used. However, there is a problem that it cannot be determined whether it is due to a malfunction of the measurement circuit, whether gas is actually used, or temporary due to fluctuations in the gas supply pressure.

  This invention is made | formed in view of the said situation, and it aims at providing the gas interruption | blocking apparatus which improves the safety | security and convenience in use of gas.

  In order to solve the above-described conventional problems, a gas shutoff device according to the present invention includes a measurement flow path communicating with a gas supply pipe, a shutoff valve for closing or opening the measurement flowpath, and a shutoff driving the shutoff valve. Valve driving means, a first vibrator attached to the upstream side of the measurement flow path, a second vibrator attached to the downstream side, the first vibrator and the second vibrator are predetermined. Transmitting means for outputting the driving signal, amplifying means for amplifying the ultrasonic signals detected by the first vibrator and the second vibrator to a predetermined level, the first vibrator and the second vibrator By alternately connecting the transmitting means and the amplifying means to a vibrator, when one vibrator is set on the receiving side, a transmission / reception switching means for switching the other vibrator to the receiving side, and the first in the amplifying means The amplification factor when the first vibrator is the receiving side and the second vibration Amplifying / comparing means for obtaining a difference from the amplification factor when the child is the receiving side, and a propagation time between the first vibrator and the second vibrator are detected from the ultrasonic signal amplified by the amplifying means. A propagation time detecting means; and a flow rate calculating section for calculating a flow rate based on the propagation time detected by the propagation time detecting means, the flow rate in a predetermined range continues for a predetermined time or more, and the amplification factor obtained by the amplification comparing section An abnormality determination unit that determines that the difference is greater than or equal to a predetermined value.

  As a result, even if there is no actual gas flow rate, if the flow rate becomes positive due to an abnormality in the gas shut-off device, misintegration will occur, and if the flow rate becomes negative, the measurement flow will be lost. By comparing the forward and reverse gains against the risk of not being judged correctly when the road is blocked or alarmed, the gas flow rate becomes positive or negative due to a malfunction of the gas cutoff device. Therefore, it is possible to prevent gas accumulation safety and misintegration.

  According to the gas shut-off device of the present invention, by comparing the amplification factor in the forward direction and the reverse direction, due to the malfunction of the gas shut-off device, even though there is actually no gas flow rate, Since it can be determined that there is an abnormality when the gas flow rate is on the plus side or minus side, it is possible to ensure safety in use of the gas and to prevent erroneous integration. Thereby, the gas interruption | blocking apparatus which aims at the safety on use of gas and improves the convenience on use of gas can be provided.

The block diagram which shows the structure of the gas interruption | blocking apparatus in the 1st Embodiment of this invention. The block diagram which shows the outline of the ultrasonic transmitter-receiver in the embodiment The flowchart which shows the operation | movement procedure of abnormality determination in the embodiment The block diagram which shows the structure of the gas interruption | blocking apparatus in the 2nd Embodiment of this invention.

  A first invention includes a measurement flow path communicating with a gas supply pipe, a shut-off valve for closing or opening the measurement flow path, a shut-off valve driving means for driving the shut-off valve, and an upstream side of the measurement flow path A first vibrator attached to the second vibrator, a second vibrator attached downstream, a transmission means for outputting a predetermined drive signal to the first vibrator and the second vibrator, and the first vibrator Amplifying means for amplifying ultrasonic signals detected by one vibrator and the second vibrator to a predetermined level, and alternately transmitting means and amplifying means for the first vibrator and the second vibrator The transmission / reception switching means for switching the other vibrator to the receiving side when one vibrator is set to the receiving side, and the amplification when the first vibrator in the amplifying means is the receiving side. The difference between the gain and the gain when the second vibrator is the receiving side Amplification comparison means, propagation time detection means for detecting the propagation time between the first vibrator and the second vibrator from the ultrasonic signal amplified by the amplification means, and propagation detected by the propagation time detection means A flow rate calculation unit that calculates a flow rate from time, an abnormality determination that determines an abnormality when a predetermined range of flow rate continues for a predetermined time or more and the difference in amplification factor obtained by the amplification comparison unit is a predetermined value or more It has a part.

  As a result, by comparing the amplification factors in the forward direction and the reverse direction, even if there is actually no gas flow rate, if the flow rate becomes positive due to an abnormality in the gas shut-off device, it will be erroneously integrated. In addition, when the flow rate is negative, the gas flow rate is positive or negative due to a malfunction of the gas shut-off device, against the danger that the measurement flow path should be shut off (alarm). Therefore, it is possible to prevent gas accumulation safety and misintegration.

  According to a second aspect of the present invention, in particular, in the first aspect, when the abnormality determination unit determines that there is an abnormality, the cutoff valve driving means drives the cutoff valve to close the measurement flow path. If the flow rate difference before and after closing is within a predetermined value, it is determined that an offset has occurred.

  As a result, if the flow rate difference before and after the shut-off is within a predetermined value, the flow rate on the plus side or the minus side is generated even if there is no flow rate, that is, the offset is generated due to the abnormality of the circuit. Can be determined.

  Moreover, although it was not possible to determine whether the gas was flowing due to the shutoff failure or the failure of the measurement circuit, the presence or absence of the offset can be correctly confirmed by measuring the flow rate offset during the shutoff. In addition, if there is a difference in the amplification factor, it can be determined that the gas shut-off device is abnormal, and it is not necessary to perform shut-off with a flow rate during shut-off, so that unnecessary battery consumption can be suppressed.

  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 block diagram showing the configuration of the gas cutoff device according to Embodiment 1. In FIG. In the present embodiment, a configuration example of a gas cutoff device using a gas meter installed in a gas user's house or the like will be described.

  The gas shut-off device 10 is installed at a predetermined position outdoors or indoors. The gas cutoff device 10 includes an ultrasonic transmitter / receiver 11, a receiving unit 12, a transmitting unit 13, a transmission / reception switching unit 14, an amplifying unit 15, a propagation time detecting unit 16, an amplification comparing unit 17, a flow rate calculating unit 18, an abnormality determining unit 19, A control unit 20, a cutoff valve 21, a cutoff valve drive unit 22, and a battery 23 are included.

  The ultrasonic transmitter / receiver 11 is connected in the path of the measurement flow path 30, and as shown in FIG. 2, the ultrasonic transducer 31 (first transducer) on the upstream side and the ultrasonic transducer 32 (first transducer) on the downstream side. The second vibrator) is disposed to face each other, and transmits and receives an ultrasonic signal.

  The receiving unit 12 receives an ultrasonic signal by the ultrasonic transducers 31 and 32 of the ultrasonic receiver 11 and amplifies the propagation time from the amplifying unit 15 that amplifies the signal to a predetermined level and the ultrasonic signal amplified by the amplifying unit 15. It has a propagation time detector 16 for detection.

  The transmission unit 13 outputs a predetermined drive signal to the ultrasonic transducers 31 and 32 of the ultrasonic transceiver 11.

  The transmission / reception switching unit 14 switches the ultrasonic transducers 31 and 32 alternately between the transmission side and the reception side, and can thereby transmit ultrasonic waves in the forward direction and the reverse direction with respect to the gas flow.

  Here, the amplifying unit 15 is configured such that the amplification factor when the ultrasonic transducer 31 is set on the receiving side and the amplification factor when the ultrasonic transducer 32 is set on the receiving side can be set separately.

  The amplification comparison unit 17 obtains a difference in amplification factor used by the amplification unit 15 when received by the ultrasonic transducers 31 and 32.

  The flow rate calculation unit 18 converts the propagation time detected by the propagation time detection unit 16 into a flow rate. The abnormality determination unit 19 determines whether or not the difference in amplification factor obtained by the amplification comparison unit 17 is greater than or equal to a predetermined value when the flow rate obtained by the flow rate calculation unit 18 continues for a predetermined time in a predetermined range.

  Here, when insulation degradation or unnecessary capacitance is connected to the reception unit 12 and the transmission unit 13, the amplification factor is changed by changing the transmission waveform or the reception waveform. In addition, the reception waveform is deformed, and thus a deviation in propagation time occurs, resulting in a flow rate offset (a positive or negative flow rate occurs even though there is no flow rate). The upstream side and the downstream side are not connected with insulation deterioration or unnecessary electrostatic capacitance in exactly the same way, and the flow rate offset occurs due to the loss of balance.

  Therefore, it is possible to determine abnormality by detecting that the balance has been lost based on the difference in amplification factor.

  In addition, when a device such as a water heater is used, a large gas flow rate is generated. However, in this case, a difference occurs in the amplification factor between the upstream side and the downstream side. Therefore, the present invention is effective in a relatively low flow rate range. .

  The control unit 20 stores flow rate information such as gas flow rate value information and integrated flow rate value information calculated by the flow rate calculation unit 18, and various types of information used in the gas shutoff device 10, and has a function of a security processing unit. It performs security processing such as operation control of each part of the gas shut-off device, communication, warning and gas shut-off. Here, the control unit 20 includes a processor and an operation program that constitute a microcomputer (microcomputer) and the like, and each function is realized by executing a predetermined operation program and performing corresponding processing in the processor.

  The shut-off valve 21 is connected in the path of the measurement flow path 30 and shuts off the gas supply by closing the measurement flow path 30 with a signal from the shut-off valve drive section 22 based on an instruction from the control section 20. is there.

  The battery 23 uses a lithium battery or the like as a power source for the gas cutoff device.

  Next, the configuration of the ultrasonic transceiver 11 and the principle of flow measurement will be described with reference to FIG. The measurement flow path 30 has a rectangular cross section communicating with the measurement flow path 30, and a pair of ultrasonic transducers 31, 32 are provided on the upstream side and the downstream side of the opposed flow path walls of the measurement flow path 30. Has been placed. These ultrasonic transducers 31 and 32 are set so that the ultrasonic propagation path obliquely crosses the gas flow flowing through the measurement flow path 30, and the ultrasonic flow is alternately transmitted and received so that the ultrasonic flow is sequentially transmitted and received. Propagation of ultrasonic waves in the opposite direction.

  At this time, the distance between the ultrasonic transducers 31 and 32, that is, the measurement distance is L, the angle of the ultrasonic propagation path with respect to the gas flow is φ, and the ultrasonic propagation time from the upstream to the downstream of the ultrasonic transducers 31 and 32 is If t1, the ultrasonic propagation time from downstream to upstream is t2, and the sound velocity is C, the flow velocity V can be obtained by the following equation.

V = L / 2 cos ((1/1/1)-(1 / t2))
Then, the instantaneous flow rate of the gas flow can be calculated from the flow velocity V and the cross-sectional area of the measurement channel 30.

  Next, the operation will be described with reference to FIG. The flow rate calculation unit 18 measures the flow rate (S1), determines whether there is a flow rate (S2), and if there is a flow rate, determines whether the flow rate is within a predetermined range (S3). It is determined whether or not the time has passed (S4), and when the predetermined time has passed, the amplification factor amplified by the amplification unit 15 is detected (S5), and the amplification comparator 17 sets the ultrasonic transducer 31 as the reception side. And the difference between the amplification factor when the ultrasonic transducer 32 is the reception side is calculated (S6). The abnormality determination unit 19 determines that the gas cutoff device is abnormal if the difference between the amplification factors is equal to or greater than a predetermined value (S7).

  In the present embodiment, the configuration in which the pair of ultrasonic transducers 31 and 32 is disposed on the upstream side and the downstream side of the channel wall facing the measurement channel 30 is described as an example. A configuration is also possible in which an upstream ultrasonic transducer 31 is installed at the entrance of the path and a downstream ultrasonic transducer 32 is installed at the exit of the measurement flow path. Further, an upstream ultrasonic transducer 31 and a downstream ultrasonic transducer 32 are installed on one surface of the flow channel wall of the measurement flow channel, and the ultrasonic transducer 31 and the downstream are disposed via the reflective surface of the flow channel wall. A configuration for transmitting and receiving an ultrasonic signal of the ultrasonic transducer 32 on the side can also be supported.

(Embodiment 2)
FIG. 4 is a block diagram showing the configuration of the gas cutoff device according to the second embodiment of the present invention. In addition, the thing of the same code | symbol as Embodiment 1 has the same structure, and abbreviate | omits description.

  Here, if the shutoff flow rate comparison unit 24 determines that the abnormality determination unit 19 is abnormal, the shutoff valve drive unit 22 drives the shutoff valve 21 to close the measurement flow path 30, and the flow rate obtained by the flow rate calculation unit 18. Are compared before and after closing, and it is determined whether or not the flow rate difference obtained by the shutoff flow rate comparing unit 24 is within a predetermined value, and if it is within the predetermined value, it is determined that there is an abnormality, and the opening operation by the shutoff valve is prohibited.

  In other words, when the difference between the forward and reverse gains is greater than a predetermined value, and the flow rate difference before and after the shut-off is within the predetermined value, the positive or negative side regardless of the flow rate. It can be determined that a flow rate is generated, that is, an offset is generated due to a circuit abnormality.

  As described above, the gas shut-off device according to the present invention can detect when the gas flow rate becomes positive or negative due to a malfunction of the gas shut-off device, even though there is no actual gas flow rate. Safety in use and misaccumulation can be prevented. Thereby, it is useful for the gas interruption | blocking apparatus which aims at the safety on use of gas, and improves the convenience on use of gas.

10 Gas shut-off device 14 Transmission / reception switching unit (transmission / reception switching means)
15 Amplification part (amplification means)
16 Propagation time detector (Propagation time detector)
17 Amplification comparison section (amplification comparison means)
18 Flow rate calculation unit 21 Shut-off valve 22 Shut-off valve drive unit 30 Measurement flow path 31 Ultrasonic transducer (first transducer)
32 Ultrasonic transducer (second transducer)

Claims (2)

A measurement channel communicating with the gas supply pipe;
A shutoff valve for closing or opening the measurement flow path;
Shut-off valve driving means for driving the shut-off valve;
A first vibrator attached to the upstream side of the measurement channel and a second vibrator attached to the downstream side;
Transmitting means for outputting a predetermined drive signal to the first vibrator and the second vibrator;
Amplifying means for amplifying the ultrasonic signals detected by the first vibrator and the second vibrator to a predetermined level;
By alternately connecting the transmitting means and the amplifying means to the first vibrator and the second vibrator, when one vibrator is set on the receiving side, the other vibrator is switched to the receiving side. Transmission / reception switching means;
Amplification comparison means for obtaining a difference between an amplification factor when the first transducer in the amplification unit is a reception side and an amplification factor when the second transducer is a reception side;
A propagation time detecting means for detecting a propagation time between the first vibrator and the second vibrator from the ultrasonic signal amplified by the amplifying means;
A flow rate calculation unit for calculating the flow rate from the propagation time detected by the propagation time detection means;
With
A flow rate in a predetermined range continues for a predetermined time or more, and has an abnormality determination unit that determines an abnormality when the difference in amplification factor obtained by the amplification comparison means is a predetermined value or more.
Gas shut-off device. When the abnormality determination unit determines that there is an abnormality, the shutoff valve driving means drives the shutoff valve to close the measurement flow path. If the flow rate difference before and after the shutoff valve is closed is within a predetermined value, an offset is set. The gas shut-off device according to claim 1, wherein it is determined that occurrence has occurred.

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