JP6987618B2 - Gas meter - Google Patents

Description

The present invention relates to a gas meter.

Conventionally, an electronic gas meter has a role not only as a measuring meter but also as a safety meter for using gas safely. However, if the gas meter is reversed (the gas inlet and gas outlet of the gas meter are connected in reverse), the original security function will not work. Therefore, the gas meter is equipped with a backflow warning (blocking) function that detects and warns of the backflow, which is the reverse gas flow (that is, the flow from the gas outlet to the gas inlet) in the gas meter that occurs when the gas meter is reversely mounted. Some are (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2001-296161

FIG. 3 is a block diagram showing a gas supply system including a gas meter according to a comparative example. As shown in FIG. 3, the gas supply system 100 has, for example, a collective pipe 101 having a large pipe volume, the collective pipe 101 is branched into an individual pipe 102 connected to each consumer, and the gas meters GM1 and the gas meters GM1 are placed on the individual pipe 102, respectively. GM2 is installed.

In such a connection environment, when gas is used by a specific consumer and gas flows through a specific gas meter GM1, a phenomenon occurs in which gas is drawn from an individual pipe 102 in which another gas meter GM2 is installed. .. Then, when this phenomenon occurs, even if the other gas meter GM2 is normally installed instead of being reversely mounted, a backflow occurs in the other gas meter GM2, so that the other gas meter GM2 may be reversely mounted. There was a case that a backflow warning was generated.

Such backflow is temporary, but it can lead to market turmoil if the gas meter is mistakenly misunderstood and a backflow warning is issued due to this temporary backflow. Therefore, it was desired to prevent false alarms of backflow warning due to temporary backflow.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a gas meter capable of preventing false alarm of backflow warning due to temporary backflow. It is in.

The gas meter of the present invention is a gas meter provided between a gas supply source and a consumer side and integrates the flow rate of gas used on the consumer side, and is an internal flow connecting a gas inlet to a gas outlet. A flow rate detecting means for detecting the flow rate of gas flowing through the path, and a backflow detecting means for detecting a backflow in the opposite direction to the flow from the gas inlet to the gas outlet based on the detected flow rate by the flow rate detecting means. The warning control means is provided with a warning control means for giving a backflow warning when a backflow is detected by the backflow detecting means, and the warning control means is based on the flow rate detected by the flow rate detecting means when the backflow warning is given. When a normal flow, which is a flow from the gas inlet to the gas outlet, is detected, the backflow warning is canceled, and when the backflow warning is not given, the positive flow is detected based on the flow rate detected by the flow rate detecting means. It is characterized by disabling the function of giving a backflow warning when a flow is detected.

According to this gas meter, if a forward flow is detected while a backflow warning is given, the backflow warning is canceled, so even if the gas meter is misidentified as being reversed due to a temporary backflow. However, when the backflow state is settled, the generated backflow warning will be canceled. Therefore, it is possible to prevent a false alarm of the backflow warning due to a temporary backflow without continuously generating the backflow warning.

According to this gas meter, the function of giving a backflow warning is disabled when a forward flow is detected when the backflow warning is not given. Therefore, when the gas meter is properly installed on the consumer side after shipment and the forward flow is detected and it can be determined that the gas meter is no longer reverse, the backflow warning function is disabled. Therefore, it is possible to prevent an erroneous backflow warning from occurring thereafter.

Further, in the gas meter of the present invention, when the function of giving a backflow warning is disabled, it is preferable that the warning control means re-enables the function of giving a backflow warning that is disabled when a predetermined condition is satisfied.

According to this gas meter, in order to re-enable the function of issuing a backflow warning that was invalidated when a predetermined condition is satisfied, a backflow warning is given when the possibility of reverse flow occurs again, for example, when the gas meter is relocated. The function can be restored to prevent the gas meter from being reversed.

Further, it is preferable that the gas meter of the present invention further includes a storage means for storing the cancellation of the backflow warning by the warning control means.

According to this gas meter, since the backflow warning is canceled, it is possible to internally remember that the backflow warning is automatically canceled, which can be useful for later analysis and the like.

According to the present invention, it is possible to provide a gas meter capable of preventing a false alarm of a backflow warning due to a temporary backflow.

It is a block diagram which shows the gas meter which concerns on embodiment of this invention. It is a flowchart which shows the processing of the gas meter which concerns on this embodiment. It is a block diagram which shows the gas supply system including the gas meter which concerns on the comparative example.

Hereinafter, the present invention will be described with reference to preferred embodiments. The present invention is not limited to the embodiments shown below, and can be appropriately modified without departing from the spirit of the present invention. Further, in the embodiments shown below, some parts of the configuration are omitted from the illustration and description, but the details of the omitted technology are within a range that does not cause any contradiction with the contents described below. Needless to say, publicly known or well-known techniques are applied as appropriate.

FIG. 1 is a block diagram showing a gas meter according to an embodiment of the present invention. As shown in FIG. 1, the gas meter 1 is provided between the gas supply source and the consumer side and integrates the gas flow rate used by the consumer side. For example, the individual pipe 102 shown in FIG. 3 It is installed above. Such a gas meter 1 includes a flow rate sensor (flow rate detecting means) 10, a control unit 20, and a liquid crystal display unit 30.

The gas meter 1 is formed with an internal flow path connecting the gas inlet to the gas outlet. In the present embodiment, the gas inlet is connected to the gas supply source and the gas outlet is connected to the consumer side. It is assumed that it is. That is, it is assumed that the gas meter 1 according to the present embodiment is properly attached.

The flow rate sensor 10 detects the flow rate of gas flowing through the internal flow path formed in the gas meter 1. In the present embodiment, the flow rate sensor 10 is an ultrasonic flow rate sensor. The ultrasonic flow rate sensors are provided, for example, on the upstream side (gas inlet side) and the downstream side (gas outlet side), respectively, and measure the gas flow rate based on the propagation time of the ultrasonic signal oscillated from both sensors. calculate. In this ultrasonic flow sensor, the propagation time changes during backflow, so that backflow can be detected. The flow rate sensor 10 may be another one as long as it can detect backflow such as a flow sensor.

The control unit 20 is composed of a CPU (Central Processing Unit) and the like, and controls the entire gas meter 1. In the present embodiment, the control unit 20 includes a backflow detection unit (backflow detection means) 21, a warning control unit (warning control means) 22, and a storage unit (storage means) 23.

The backflow detection unit 21 detects a backflow that is opposite to the flow from the gas inlet to the gas outlet based on the flow rate detected by the flow sensor 10. That is, the backflow detection unit 21 detects the backflow when the detected flow rate on the negative side is obtained by the flow rate sensor 10.

The warning control unit 22 gives a backflow warning when a backflow is detected by the backflow detection unit 21. The backflow warning is displayed by the liquid crystal display unit 30. It is preferable that the warning control unit 22 gives a backflow warning when the backflow detection unit 21 continuously detects the backflow a predetermined number of times (an integer of 2 or more). This is because when the instantaneous flow rate becomes negative due to pulsation, it is possible to prevent erroneous determination as reverse.

Further, in the present embodiment, when the warning control unit 22 warns of a backflow, when a normal flow, which is a flow from the gas inlet to the gas outlet, is detected based on the flow rate detected by the flow sensor 10. , The backflow warning is canceled (that is, the backflow warning display on the liquid crystal display unit 30 is erased).

In this case, the warning control unit 22 may cancel the backflow warning when the forward flow rate (instantaneous flow rate) is continuously detected for the second predetermined number of times (integer of 2 or more). The backflow warning may be canceled when the flow rate classification is registered.

Generally, the gas meter 1 is equipped with a safety function called a usage time cutoff function. In the usage time shutoff function, the continuous use time (continuous use time) is set for each of the plurality of flow rate categories, and the gas meter 1 closes the shutoff valve when the use exceeds the predetermined continuous use time. It has become. In this function, the control unit 20 determines the flow rate classification. At this time, the control unit 20 measures the flow rate for a predetermined period (a period during which the instantaneous flow rate can be calculated a plurality of times), and determines the flow rate classification from the average value of the plurality of instantaneous flow rates. The flow rate classification is not limited to the average value of a plurality of instantaneous flow rates, and may be a representative value such as an average value or a median value excluding a peculiar flow rate.

When the backflow warning is generated, the gas meter 1 is in a state where the flow rate classification is not registered (specified) due to the generation of the flow rate on the negative side. When the flow rate on the positive side is generated from this state, the flow rate classification according to the flow rate is registered (specified). In the present embodiment, the warning control unit 22 cancels the backflow warning when the flow rate classification is registered (specified) while the backflow warning is being given. This is because it is possible to prevent a situation in which a normal flow is temporarily detected due to the pulsation of the gas and the backflow warning is canceled at the time of reverse rotation.

Further, the warning control unit 22 disables the function of giving a backflow warning when a normal flow is detected based on the flow rate detected by the flow rate sensor 10 when the backflow warning is not given in the state where the shipping state is canceled. It is preferable to make it. At this time, even if the warning control unit 22 disables the function of giving a backflow warning when a forward flow rate (instantaneous flow rate) is continuously detected a third predetermined number of times (an integer of 2 or more). Alternatively, the function of giving a backflow warning may be disabled when the flow rate classification is registered.

The backflow warning once invalidated is enabled when the gas meter 1 is operated by a predetermined operation and returns to the shipping state again (an example when the predetermined condition is satisfied). In addition, the function to issue a backflow warning once disabled is not limited to the case of returning to the shipping state, but when other operations are performed or when the gas flow rate is not detected for a period of one month or more, etc. , May be activated when other conditions are met.

The storage unit 23 stores a program for realizing each function of the gas meter 1, various variables necessary for controlling the gas meter 1, and the like. Further, in the present embodiment, the storage unit 23 stores that the backflow warning has occurred, that the backflow warning has been canceled, and that the backflow warning function has been disabled.

FIG. 2 is a flowchart showing the processing of the gas meter 1 according to the present embodiment. As shown in FIG. 2, first, the control unit 20 determines whether or not the backflow warning function is enabled (S1). When it is determined that the backflow warning function is not enabled (S1: NO), the process shown in FIG. 2 ends.

When it is determined that the backflow warning function is enabled (S1: YES), the control unit 20 determines whether a backflow warning is being generated (S2). When it is determined that the backflow warning is occurring (S2: YES), the warning control unit 22 determines whether the forward flow is continuously obtained N times (second predetermined number of times) (S3). When it is determined that the forward flow is continuously obtained N times (S3: YES), the warning control unit 22 cancels the backflow warning (S4). Then, the process shown in FIG. 2 is completed. On the other hand, when it is determined that the forward flow has not been obtained N times in a row (S3: NO), the backflow warning is not canceled and the process shown in FIG. 2 ends.

By the way, when it is determined that the backflow warning is not occurring (S2: NO), the warning control unit 22 determines whether the forward flow is continuously obtained N times (third predetermined number of times) (S5). When it is determined that the forward flow is continuously obtained N times (S5: YES), the warning control unit 22 invalidates the backflow warning (S6). Then, the process shown in FIG. 2 is completed. On the other hand, when it is determined that the forward flow has not been obtained N times in a row (S5: NO), the backflow warning is not invalidated and the process shown in FIG. 2 ends.

In this way, according to the gas meter 1 according to the present embodiment, when a forward flow is detected during the backflow warning, the backflow warning is canceled, so that the gas meter 1 reverses even due to a temporary backflow. Even if it is mistakenly attached, the generated backflow warning will be canceled when the backflow state is settled. Therefore, it is possible to prevent a false alarm of the backflow warning due to a temporary backflow without continuously generating the backflow warning.

In addition, the function of giving a backflow warning is disabled when a forward flow is detected when the backflow warning is not given. Therefore, when the gas meter is properly installed on the consumer side after shipment and the forward flow is detected and it can be determined that the gas meter is no longer reverse, the backflow warning function is disabled. Therefore, it is possible to prevent an erroneous backflow warning from occurring thereafter.

In addition, in order to re-enable the function that gives a backflow warning that was disabled when the product returns to the shipping state, a function that gives a backflow warning when the possibility of reverse flow occurs again, for example, when the gas meter is relocated. It can be restored to prevent the gas meter from being reversed.

Further, since the backflow warning is memorized, the fact that the backflow warning is automatically canceled can be memorized internally, which can be useful for later analysis and the like.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and changes may be made without departing from the spirit of the present invention, and other examples may be made as appropriate. Techniques may be combined.

For example, in the above embodiment, the flow rate sensor 10 is assumed to be an ultrasonic flow rate sensor, but the present invention is not limited to this, and any sensor capable of detecting backflow is not particularly limited to the ultrasonic flow rate sensor.

Further, if possible, the gas meter 1 may be equipped with a notification function to notify the consumer side when the backflow warning is canceled. In addition, the liquid crystal display unit 30 may display that the backflow warning has been canceled or disabled. In particular, when it is displayed that the gas meter has been invalidated, the gas operator can know that it is necessary to return the gas meter 1 to the shipping state when the gas meter 1 is relocated.

1: Gas meter 10: Flow rate sensor (flow rate detection means)
20: Control unit 21: Backflow detection unit (backflow detection means)
22: Warning control unit (warning control means)
23: Storage unit (memory means)
30: Liquid crystal display

Claims (3)

It is a gas meter installed between the gas supply source and the consumer side and integrates the flow rate of the gas used on the consumer side.
A flow rate detecting means for detecting the flow rate of gas flowing through the internal flow path connecting the gas inlet to the gas outlet, and
A backflow detecting means for detecting a backflow that is opposite to the flow from the gas inlet to the gas outlet based on the flow rate detected by the flow rate detecting means.
A warning control means for giving a backflow warning when a backflow is detected by the backflow detecting means is provided.
The warning control means warns of backflow when a forward flow, which is a flow from the gas inlet to the gas outlet, is detected based on the flow rate detected by the flow rate detecting means during the backflow warning. A gas meter characterized by disabling the function of giving a backflow warning when the forward flow is detected based on the flow rate detected by the flow rate detecting means when the backflow warning is not given. The gas meter according to claim 1 , wherein the warning control means re-enables the function of giving a backflow warning that was invalidated when a predetermined condition is satisfied when the function of giving a backflow warning is disabled. The gas meter according to claim 1 or 2 , further comprising a storage means for storing the cancellation of the backflow warning by the warning control means.

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