JP2019095314A - Gas meter - Google Patents

Abstract

To provide a gas meter with which it is possible to prevent false output of a backflow alarm due to a temporary backflow.SOLUTION: Provided is a gas flow meter 1 installed between a gas supply source and a consumer for accumulating the flow rates of a gas used on the consumer side, comprising: a flow rate sensor 10 detecting the flow rate of a gas flowing in an internal passage linking from a gas inflow port to a gas outflow port; a backflow detection unit 21 for detecting a backflow that is reverse to a flow heading from the gas inflow port toward the gas outflow port, on the basis of the flow rate detected by the flow rate sensor 10; and an alarm control unit 22 for outputting a backflow alarm when a backflow is detected by the backflow detection unit 21. The alarm control unit 22 cancels a backflow alarm when, while a backflow alarm is on, a normal flow heading from the gas inflow port toward the gas outflow port is detected on the basis of the flow rate detected by the flow rate sensor 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas meter.

  In the past, electronic gas meters have not only functions as meters but also as safety meters for the safe use of gas. However, if the gas meter is reversed (the gas inlet and the gas outlet of the gas meter are reversely connected), the inherent security function will not work. Therefore, the gas meter is equipped with a reverse flow warning (shutoff) function that detects and warns of a reverse flow that is the flow of reverse gas (that is, the flow from the gas outlet to the gas inlet) in the gas meter that occurs during reverse installation. (See, for example, Patent Document 1).

JP, 2001-296161, A

  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 with a large pipe volume, and the collective pipe 101 branches into individual pipes 102 connected to each customer, and the gas meters GM1, GM1 are respectively arranged on the individual pipes 102. GM2 is installed.

  In such a connection environment, when a specific consumer uses a gas and the gas flows through the specific gas meter GM1, a phenomenon occurs in which the gas is drawn from the individual pipe 102 in which the other gas meter GM2 is installed. . And if this phenomenon occurs, even if the other gas meter GM2 is properly installed instead of being reversed, backflow may occur in the other gas meter GM2, so the other gas meter GM2 may be reversed. The backflow warning may occur as there is a

  Although such a backflow is temporary, it may be mistaken that the gas meter is reversed due to this temporary backflow, and a backflow warning may cause market confusion. Therefore, it was desirable to prevent false alarms of backflow warnings due to temporary backflow.

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

  The gas meter of the present invention is a gas meter provided between the gas supply source and the consumer side and integrating the flow rate of the gas used on the consumer side, and is an internal flow connecting the gas inlet to the gas outlet. A flow rate detecting means for detecting a flow rate of gas flowing in the passage; and a reverse flow detecting means for detecting a reverse flow in a direction opposite to the flow from the gas inlet to the gas outlet based on the detected flow rate by the flow rate detecting means And warning control means for performing a backflow warning when the backflow detection means detects the backflow, and the warning control means is based on the flow rate detected by the flow rate detection means when the backflow warning is issued. The apparatus is characterized in that the reverse flow warning is canceled when a normal flow, which is a flow from the gas inlet to the gas outlet, is detected.

  According to this gas meter, it is falsely recognized that the gas meter has been reversed due to the temporary backflow, because the backflow warning is canceled when the forward flow is detected when the backflow warning is being issued. Also, when the backflow condition is settled, the generated backflow warning is released. For this reason, it is possible to prevent a false alarm on the backflow warning due to the temporary backflow without continuously generating the backflow warning.

  Further, in the gas meter of the present invention, the warning control means invalidates the function of performing the backflow warning when the forward flow is detected based on the detected flow rate by the flow rate detection means when the backflow warning is not performed. It is preferable to

  According to this gas meter, the function to perform the backflow warning is disabled when the forward flow is detected when the backflow warning is not performed. For this reason, when the gas meter is properly installed on the customer side after shipment and a positive flow is detected and it can be concluded that the reverse flow is no longer reversed, the backflow warning function is invalidated. Therefore, it is possible to prevent the occurrence of an erroneous backflow warning thereafter.

  Further, in the gas meter according to the present invention, preferably, the warning control means re-enables the function of performing the backflow warning disabled when a predetermined condition is satisfied, when the function of performing the backflow warning is disabled.

  According to this gas meter, in order to re-enable the function of performing the backflow warning invalidated when the predetermined condition is satisfied, for example, when the possibility of reverse installation occurs again at the time of transfer of the gas meter, etc., the backflow warning is performed. The function can be restored to prevent the gas meter from being reversed.

  Preferably, the gas meter according to the present invention further comprises storage means for storing that the backflow warning has been released by the warning control means.

  According to this gas meter, since it is memorize | stored that backflow warning was cancelled | released, it can be memorize | stored inside internally that backflow warning was cancelled | released, and it can be used for later analysis etc.

  ADVANTAGE OF THE INVENTION According to this invention, the gas meter which can prevent the misreport of the backflow warning by temporary backflow can be provided.

It is a block diagram showing a gas meter concerning an embodiment of the present invention. It is a flow chart which shows processing of a gas meter concerning this embodiment. It is a block diagram which shows the gas supply system containing the gas meter which concerns on a comparative example.

  Hereinafter, the present invention will be described according to preferred embodiments. The present invention is not limited to the embodiments described below, and can be modified as appropriate without departing from the spirit of the present invention. Also, in the embodiment shown below, there are places where illustration and explanation of a part of the configuration is omitted, but the details of the omitted technique are within the range where the contradiction does not occur with the contents described below. Needless to say, well-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 rates used on the consumer side, and for example, the individual piping 102 shown in FIG. It is installed on top. 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 passage connecting the gas inlet to the gas outlet, and 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 shall be. That is, the gas meter 1 according to the present embodiment is assumed to be properly attached.

  The flow rate sensor 10 detects the flow rate of gas flowing in 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 sensor is provided, for example, on the upstream side (gas inlet side) and the downstream side (gas outlet side), and the gas flow rate is determined based on the propagation time of the ultrasonic signal oscillated from both sensor units. calculate. In this ultrasonic flow sensor, since the propagation time is changed at the time of backflow, the backflow can be detected. The flow rate sensor 10 may be any other sensor that can detect backflow, such as a flow sensor.

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

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

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

  Furthermore, in the present embodiment, the warning control unit 22 detects a forward flow, which is a flow from the gas inlet to the gas outlet, based on the detected flow rate by the flow rate sensor 10, while performing the reverse flow warning. And the backflow warning is canceled (that is, the backflow warning display to the liquid crystal display unit 30 is erased).

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

  In general, the gas meter 1 is equipped with a security function called an operation time cut-off function. In the use time shut-off function, the continuous use time (continuous use time) is defined for each of a plurality of flow rate divisions, and the gas meter 1 closes the shut-off valve when there is use beyond the predetermined continuous use time. It has become. In this function, the control unit 20 determines the flow rate division. At this time, the control unit 20 measures the flow rate in a predetermined period (a period in which the calculation of the instantaneous flow rate can be performed a plurality of times), and determines the flow rate division from the average value of the instantaneous flow rates a plurality of times. The flow rate classification is not limited to the average value of the instantaneous flow rates a plurality of times, and may be a representative value such as an average value or median value excluding the specific flow rate.

  When the backflow warning is generated, the gas meter 1 is in a state where the flow rate division is not registered (specified) due to the generation of the negative side flow rate. From this state, when the flow on the positive side occurs, a flow rate division corresponding to the flow is registered (specified). In the present embodiment, the warning control unit 22 cancels the backflow warning when the flow rate classification is registered (specified) when the backflow warning is being issued. This is because it is possible to prevent a situation in which the forward flow is temporarily detected at the time of reversing by the pulsation of the gas and the reverse flow warning is released.

  Furthermore, the warning control unit 22 invalidates the function of performing the backflow warning when the normal flow is detected based on the detected flow rate by the flow rate sensor 10 when the backflow warning is not performed in the state where the shipping state is released. It is preferable to At this time, even if the warning control unit 22 detects the forward flow (instantaneous flow rate) continuously for the third predetermined number of times (an integer of 2 or more), the warning control unit 22 disables the function to issue the backflow warning. Alternatively, the function to issue a backflow alert may be disabled when the flow rate segment is registered.

  The backflow warning that has been invalidated once is validated when the gas meter 1 is subjected to a predetermined operation and returned to the shipping state again (an example when the predetermined condition is satisfied). It should be noted that the function of performing the backflow warning that has been invalidated is not limited to the case of returning to the shipping state, but may be performed when other operations are performed or the gas flow rate is not detected over a period such as January or more , May be enabled when the other conditions are met.

  The storage unit 23 stores programs for realizing the functions of the gas meter 1 and various variables and the like necessary for controlling the gas meter 1. Furthermore, in the present embodiment, the storage unit 23 is configured to store the fact that the backflow warning has occurred, that the backflow warning has been canceled, and that the backflow warning function has been invalidated.

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

  If it is determined that the backflow warning function is enabled (S1: YES), the control unit 20 determines whether a backflow warning is occurring (S2). If it is determined that the backflow warning is occurring (S2: YES), the warning control unit 22 determines whether the normal flow has been obtained N times (second predetermined number of times) continuously (S3). If it is determined that the normal flow has been obtained N times consecutively (S3: YES), the warning control unit 22 cancels the backflow warning (S4). Then, the process illustrated in FIG. 2 ends. On the other hand, when it is determined that the normal flow has not been obtained N times consecutively (S3: NO), the process shown in FIG. 2 ends without canceling the backflow warning.

  By the way, when it is determined that the backflow warning is not occurring (S2: NO), the warning control unit 22 determines whether the normal flow has been obtained N times (third predetermined number of times) continuously (S5). If it is determined that the normal flow has been obtained N times consecutively (S5: YES), the warning control unit 22 invalidates the backflow warning (S6). Then, the process illustrated in FIG. 2 ends. On the other hand, when it is determined that the normal flow has not been obtained N times consecutively (S5: NO), the process shown in FIG. 2 is ended without invalidating the backflow warning.

  In this manner, according to the gas meter 1 of the present embodiment, when the forward flow is detected when the backward flow warning is given, the gas meter 1 is reversed even by the temporary reverse flow to cancel the reverse flow warning. Even if it is misidentified as being attached, if the backflow condition is settled, the generated backflow warning will be cancelled. For this reason, it is possible to prevent a false alarm on the backflow warning due to the temporary backflow without continuously generating the backflow warning.

  In addition, when the backflow warning is not performed and the forward flow is detected, the function to perform the backflow warning is disabled. For this reason, when the gas meter is properly installed on the customer side after shipment and a positive flow is detected and it can be concluded that the reverse flow is no longer reversed, the backflow warning function is invalidated. Therefore, it is possible to prevent the occurrence of an erroneous backflow warning thereafter.

  Also, in order to re-enable the function to perform the backflow warning that has been invalidated when returning to the shipping state, for example, when the possibility of reverse installation occurs again at the time of transfer of the gas meter, etc. It is possible to prevent the gas meter from being reversed by returning it.

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

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the said embodiment, A change may be added in the range which does not deviate from the meaning of this invention. You may combine the techniques of

  For example, although an ultrasonic flow sensor is assumed as the flow sensor 10 in the above embodiment, the present invention is not limited to this, and it is not limited to the ultrasonic flow sensor, as long as it is a sensor capable of detecting a backflow.

  Furthermore, the notification function may be installed in the gas meter 1 if possible, and when the backflow warning is released, this may be notified to the consumer side. In addition, the liquid crystal display unit 30 may be configured to display that the backflow warning has been canceled or that it has been invalidated. In particular, when it is displayed that the gas meter 1 has been revoked, it is possible for the gas company to know that it is necessary to return to the shipping state when the gas meter 1 is transferred.

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 (storage means)
30: Liquid crystal display unit

Claims (4)

A gas meter which is provided between a gas supply source and a consumer side and integrates the flow rate of gas used on the consumer side,
Flow rate detection means for detecting the flow rate of gas flowing in an internal flow path connecting the gas inlet to the gas outlet;
Backflow detection means for detecting a backflow in a direction opposite to the flow from the gas inlet to the gas outlet based on the flow detected by the flow detector.
Warning control means for performing a backflow warning when the backflow is detected by the backflow detection means;
The warning control means is a backflow warning, and when the forward flow which is a flow from the gas inlet to the gas outlet is detected based on the detected flow rate by the flow rate detecting means, the reverse flow warning A gas meter characterized by releasing. The warning control means is characterized in that the function of performing the backflow warning is disabled when the normal flow is detected based on the flow rate detected by the flow rate detection means when the backflow warning is not performed. The gas meter according to Item 1. The gas meter according to claim 2, wherein the warning control means re-enables the function of performing the backflow warning that has been disabled when a predetermined condition is satisfied, when the function of performing the backflow warning is disabled. The gas meter according to any one of claims 1 to 3, further comprising storage means for storing that the backflow warning has been canceled by the warning control means.

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