JP5341403B2 - Gas shut-off device, flow rate change determination method therefor, and controller for gas shut-off device - Google Patents

Description

  The present invention relates to a gas shut-off device and method used for a gas meter or the like installed in a gas supply line to each home, and a controller for the gas shut-off device, and in particular, a normal operation or forgetting to turn it off. By improving the flow rate change presence / absence judgment method to determine whether there is a substantial flow rate change in use, it is possible to shut off the safety duration at an appropriate timing, thereby improving both security functions and services Related to the technology.

  A gas meter with a built-in gas flow meter is attached to the entrance of the gas supply line to each household. The gas meter measures the gas flow rate passing through the gas supply line, and the measured gas flow rate is used for the periodic calculation of the billed gas charge. In addition to the basic function of measuring the gas flow rate, such a gas meter has a security function of shutting off the gas supply when an abnormal condition occurs. This security function is a function of shutting off gas by a shutoff valve provided in the gas flow path of the gas meter in response to detection of an abnormal use state such as detection of an earthquake or gas leakage or forgetting to turn off the appliance.

  FIG. 11 is a diagram showing a safety duration setting value used for the shut-off function when the safety duration is over, which is one of the security functions. This function means that if the gas flow rate continues to be used after the occurrence of the gas flow rate is detected, and if the duration time is excessively long, some abnormal use condition such as a gas leak has occurred. It is a function that blocks gas.

  As shown in FIG. 11, a large water heater with a large gas flow rate is continuously used only for about 30 minutes, while a stove with a small gas flow rate will be used continuously for a long time. On the premise, the safety duration when the gas flow rate is large is set short, and the safety duration when the gas flow rate is small is set long.

  The gas meter determines that the use of some gas appliance has started when the gas flow rate is generated or when the gas flow rate is increased, measures the time during which the flow rate continues, and shows the safety duration time shown in FIG. When the flow rate continues beyond the limit, gas is shut off for security reasons. That is, based on the measured gas flow rate, the safety duration over cutoff is performed using a plurality of preset safety duration values that individually correspond to a plurality of preset flow rate categories.

  On the other hand, since the flow rate change level of the gas appliance during normal operation is, for example, 3% (or 51.82 L / h) or less, conventionally, a threshold value (for example, according to the flow rate change level of such a gas appliance, for example, 3% or 51.82 L / h), and when a change in flow rate exceeding this threshold is detected, the flow rate change in accordance with the user's intention to continue using the appliance (for example, operation mode switching operation condition setting, etc.) Therefore, it is determined that there has been a change in flow rate based on the operation / selection), and the duration measurement timer is reset to zero-start (see, for example, Patent Document 1 and Patent Document 2).

  In this way, by resetting the duration measurement timer based on the flow rate change presence / absence determination, the start point of the duration measurement is updated, so that the user intends to continue using the appliance during normal operation of the gas appliance. It is possible to avoid gas blockage that is contrary.

In such a flow rate change presence / absence determination, the flow rate from a reference value at a certain reference point is based on the characteristic that the flow rate change during normal operation of a proportional control device such as a fan heater, a water heater, or a fuel cell is relatively gradual. As a change, it is determined that there is a change in flow rate when a flow rate change equal to or greater than a threshold value (eg, 3% or 51.82 L / H) is continuously detected a plurality of times (eg, 3 times). Has been updated.
JP2005-241405 JP 2008-32417 A

  However, the conventional methods for determining whether or not there is a change in flow rate during safety duration interruption as described above have problems such as “occurrence of early interruption”, “occurrence of late interruption”, and “unable to determine change in flow rate in decreasing direction”. ing. Hereinafter, these problems will be described sequentially.

[Occurrence of premature break]
In a proportional control device such as a fan heater, a water heater, or a fuel cell, even if a flow rate change occurs in accordance with the user's intention to continue using the device, the actual flow rate change example of the fan heater shown in FIG. As described above, there may be a case where the flow rate change does not occur a plurality of times (for example, 3 times) that are equal to or greater than a threshold value (eg, 3% or 51.82 L / h). In this case, the duration measurement timer is not cleared and the start point of the duration measurement is not updated, so that an early gas cutoff called “early expiration” is performed against the user's intention to continue using the instrument. End up. This reduces the convenience of heating appliances such as fan heaters and leads to service degradation.

[Occurrence of delay]
As in the example of the actual flow rate change of the fan heater shown in FIG. 13, when only a flow rate change below the lowest level (for example, 100 L / h) of the ignition flow rate that appears during normal ignition of a general gas appliance occurs (for example, 70 to 80 L / hour). In h), it is determined that there is a flow rate change for every flow rate change. In this case, even though the user who has forgotten to turn off the gas appliance has not performed the operation after that, the duration measurement timer continues to be cleared, so the start point of the duration measurement continues to be updated. A necessary gas shut-off cannot be performed in a timely manner on a gas appliance in a non-use state, and a gas shut-off delay called “slow break” occurs.

[Unable to determine flow rate change in decreasing direction]
As in the flow rate change detection example of the proportional control instrument shown in FIG. 14, a threshold value (for example, 3% or 51%) is used as the flow rate change from the reference value at a certain reference point even though the flow rate is actually decreasing. .82 L / h) or more (for example, three times) when the flow rate change is not detected, it is not determined that there is a flow rate change. In this way, when the change in flow rate in the decreasing direction cannot be determined, the reference value that should be performed when it is determined that there is a change in flow rate is not updated. It will deviate, leading to a decrease in the accuracy of subsequent determinations. This hinders the realization of safety duration interruption at a timely timing.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and its purpose is to determine whether or not there is a substantial flow rate change during normal operation or in a non-use state where forgetting to turn off. By improving the flow rate change presence / absence judgment method, it is possible to shut off the safety duration at an appropriate timing, thereby improving both the safety function and service, the flow rate change judgment method using the same, and the gas cut-off It is to provide a controller for the device.

  The gas shut-off device of the present invention includes a shut-off means for shutting off a gas flowing through the target gas flow path, and a measuring means for measuring at least a gas flow rate as a physical quantity related to the gas flowing through the target gas flow path, and a gas flowing through the target gas flow path In the gas shut-off device that shuts off the target gas flow path by the shut-off means when shut-off is necessary, first, the following basic configuration is provided.

  That is, the gas shut-off device of the present invention is preset in advance so as to individually correspond to the average flow rate calculation means for calculating the average flow rate of the gas flow rate from the measurement data obtained by the measurement means and a plurality of preset flow rate categories. Based on the current set value selected according to the flow rate category to which the average flow rate obtained by the average flow rate calculation unit belongs from the plurality of set safety duration set values, using a timer for duration measurement The measurement time by the duration measurement means for measuring the duration of the gas flow rate flowing through the target gas flow path and the duration measurement timer is set to the safe duration setting value selected as the current setting value. At that time, the safety means for shutting off the target gas flow path by the shut-off means, and the average flow rate obtained by the average flow rate calculation means are preset with respect to the flow rate before the change. A flow rate change detecting means for detecting a flow rate change when the threshold value changes more than a threshold value, a counting means for counting the number of flow rate changes detected by the flow rate change detecting means, and a flow rate change count counted by the counting means. Stores a flow rate change presence / absence determining unit that determines that there is a substantial flow rate change when a predetermined number of times is reached, and data obtained in the apparatus based on the measurement data obtained by the measurement unit A storage means is provided.

The gas shut-off device of the present invention has the following technical features in order to achieve the above object, in addition to having the basic configuration as described above.
In one aspect of the gas shutoff device of the present invention, the flow rate change detecting means uses an average flow rate by using a flow rate change minimum value representing a minimum level of flow rate change of the proportional control instrument as the preset threshold value. Including a flow rate change detecting means for premature interruption prevention detection for detecting a flow rate change when the flow rate changes from the flow rate before the change by the minimum value of the flow rate change, and the counting means includes a flow rate change detection means for the premature interruption prevention determination. Including a counting means for determining whether or not the flow rate is equal to or greater than the threshold value detected by the step, and the means for determining whether or not the flow rate has changed measures the determination time using a timer for determining whether or not the flow rate has changed. While determining whether or not there is a flow rate change for premature disconnection prevention determination, the number of flow rate changes counted by the count means for determining premature disconnection reaches a predetermined number of times set in advance. A flow rate change presence / absence determining means for determining that there is a substantial flow rate change in the case of a premature disconnection, and the security means has a substantial flow rate change by the flow rate change presence / absence determining means for the premature cut prevention determination. When it is determined, the duration measurement timer and the premature break prevention determination timer are zero-started, and the time determined to have a flow rate change and the flow rate at that time as new original flow rate data It is configured to register in the storage means.

  According to the gas shut-off device of this aspect, for example, by using a flow rate minimum value of 30 L / h as a threshold value, detecting a flow rate change of at least 30 L / h and counting the number of occurrences, It can be determined whether the flow rate change of 30 L / h or more occurs for a predetermined number of times (N times) or more ”. According to the flow rate change presence / absence determination for premature disconnection prevention determination, even if the flow rate change during normal operation is a proportional control device, the flow rate change of the gas flow used in the device is detected and detected. It can be determined that there is a typical flow rate change. As a result, whenever a flow rate change occurs in accordance with the user's intention to continue using the instrument, the duration measurement timer can be cleared and the start point of the duration measurement can be updated, so that it is possible to prevent premature disconnection with high reliability.

  Further, the flow rate change determination method by the gas shut-off device and the controller for the gas shut-off device according to the present invention grasp the function of the gas shut-off device from the viewpoint of the method and the controller used in the apparatus. It is.

  According to the present invention, by improving the flow rate change presence / absence determination method for determining the presence or absence of a substantial flow rate change during normal operation or in a non-use state that has not been turned off, it is possible to shut off the safety duration at an appropriate timing. Thus, it is possible to provide a gas shut-off device that can improve both the security function and the service, a flow rate change determination method using the gas shut-off device, and a controller for the gas shut-off device.

[Constitution]
FIG. 1 is a functional block diagram showing a configuration of a gas meter according to one embodiment to which a gas cutoff device of the present invention is applied. As shown in FIG. 1, a gas meter 100 according to this embodiment includes a controller (controller) 110 that realizes a characteristic function of the gas cutoff device of the present invention, and a measurement that measures a physical quantity related to a gas flowing through a target gas flow path. The unit 120 includes a shut-off valve 130 that shuts off gas, a display unit 140 that displays various data, and a communication device 150 that performs data communication with the outside.

  The measurement unit 120 includes a gas flow rate sensor 121 that measures the gas flow rate Q flowing through the target gas flow path, and various sensors 122 that measure supply pressure, gas temperature, acceleration, and the like as other various physical quantities. .

  The controller 110 includes an average flow rate calculation unit 111, a flow rate change detection unit 112, a count unit 113, a flow rate change presence / absence determination unit 114, a duration measurement unit 115, a security unit 116, and a storage unit 117. 2 and 3 show the detailed configuration of the flow rate change detection unit 112, the count unit 113, the flow rate change presence / absence determination unit 114, and the duration measurement unit 115 in the controller 110 together with the data flow. It is a block diagram.

  The average flow rate calculation unit 111 is a means for calculating the average flow rate of the gas flow rate from the measurement data obtained by the gas flow rate sensor 121 of the measurement unit 120. Here, as the average flow rate, an average value of measurement data having a continuous gas flow rate is calculated every predetermined time interval set in advance, for example, every 30 seconds.

  The flow rate change detection unit 112 compares the difference between the average flow rate obtained by the average flow rate calculation unit 111 and the average flow rate before the change with a preset threshold value for detection, and the average flow rate is the flow rate before the change. Is a means for detecting a change in flow rate when there is a change beyond the threshold. As shown in FIG. 2, the flow rate change detection unit 112 includes a flow rate change detection unit 1121 for preventing an early break prevention, a flow rate change detection unit 1122 for a late cut prevention determination, and a flow rate change detection unit 1123 for a decrease direction change determination. It has.

  The flow rate change detection unit 1121 for premature disconnection determination uses the lowest flow rate change value of 30 L / h as the preset threshold value Qd1, so that the average flow rate becomes the threshold value Qd1 (= 30 L / h) from the flow rate before the change. h) A means for detecting a change in the flow rate when it has changed above.

  The late change prevention determination flow rate change detection unit 1122 uses the minimum value of the ignition flow rate of 100 L / h as the preset threshold value Qd2, so that the average flow rate is changed from the flow rate before the change to the threshold value Qd2 (= 100 L / h). h) A means for detecting a change in the flow rate when it has changed above.

  The decrease direction change determination flow rate change detection unit 1123 uses a decrease direction change determination value of 3% as the preset threshold value Qd3, so that the average flow rate becomes the threshold value Qd3 (= 3%) from the flow rate before the change. ) A means for detecting a change in flow rate when the above changes.

  The counting unit 113 is a means for counting the number of flow rate changes detected by the average flow rate calculating unit 111. As shown in FIG. 2, the premature cut prevention determining counting unit 1131 and the decreasing direction change determining counting unit 1133 are arranged. I have.

The early-break prevention determination counting unit 1131 is a means for counting the number of flow rate changes equal to or greater than the threshold value Qd1 detected by the early-break prevention determination flow rate change detection unit 1121.
The decrease direction change determination counting unit 1133 is a means for counting the number of flow rate changes equal to or greater than the threshold value Qd3 (= 3%) detected by the decrease direction change determination flow rate change detection unit 1123.

  The flow rate change presence / absence determination unit 114 measures the determination time using a determination timer, and when the flow rate change count counted by the count unit 113 reaches a preset predetermined number, there is a substantial flow rate change. It is a means to determine. As shown in FIG. 2, the flow rate change presence / absence determination unit 114 includes a flow rate change presence / absence determination unit 1141 for early cut prevention determination, a timer 1141T for early cut prevention determination, and a flow change presence / absence determination unit 1142 for late cut prevention determination. A prevention determination timer 1142T, a decrease direction change determination flow rate change presence / absence determination unit 1143, and a decrease direction change determination timer 1143T are provided.

  The premature break prevention determination flow rate change presence / absence determination unit 1141 performs flow rate change presence / absence determination for premature break prevention determination while measuring the determination time using the premature cut prevention determination timer 1141T, and the premature cut prevention determination count unit 1131. Is a means for determining that there is a substantial change in the flow rate when the number of flow rate changes counted by the number of times reaches a predetermined number (N times) set in advance. As a modified example, there is a substantial flow rate change when the number of flow rate changes counted by the premature break prevention determination counting unit 1131 reaches a predetermined number of times (N times) within a predetermined time set in advance. May be determined.

  The late-break prevention determination flow rate change presence / absence determination unit 1142 performs the flow-rate change determination for late-break prevention determination while measuring the determination time using the late-break prevention determination timer 1142T, and detects the delay change prevention flow rate change detection. It is means for determining that there is a substantial flow rate change when the flow rate change is detected by the unit 1122.

  The decrease direction change determination flow rate change presence / absence determination unit 1143 uses the decrease direction change determination timer 1143T to measure the determination time while performing the decrease direction change determination flow rate change presence / absence determination, and sets a predetermined time (X Means for determining that there is a substantial change in flow rate in the decreasing direction when the flow rate change count counted by the decreasing direction change determination counting unit 1133 has reached a predetermined number (M times) set in advance within (time). is there. For example, the predetermined number (M times) is set to 3 times, and the predetermined time (X time) is set to 3 minutes. During this 3 minutes, the flow rate change count counted by the decreasing direction change determination counting unit 1133 is 3 times. It is conceivable to determine that there is a substantial change in the flow rate in the decreasing direction when it reaches.

  The duration measurement unit 115 includes a flow rate to which the average flow rate obtained by the average flow rate calculation unit 111 belongs from among a plurality of preset safety duration values that individually correspond to a plurality of preset flow rate categories. This is means for measuring the duration of the flow rate of the gas flowing through the target gas flow path using a duration measurement timer 115T as shown in FIG. 3 based on the current set value selected according to the category.

  The safety unit 116 detects the target gas flow path by the shutoff valve 130 when the measurement time by the duration measurement timer 115T of the duration measurement unit 115 reaches the safety duration set value selected as the current set value. It is a means to block. The security unit 116 includes a flow rate category to which an average flow rate obtained by the average flow rate calculation unit 111 belongs among a plurality of preset safety duration values that individually correspond to a plurality of preset flow rate categories. One set value is selected according to.

  The security unit 116 also resets the duration measurement timer 115T and the premature cut prevention determination timer 1141T when the premature break prevention determination flow rate change presence / absence determination unit 1141 determines that there is a substantial flow rate change. At the same time as starting zero, the time at which it is determined that there is a change in flow rate and the flow rate change ΔQ at that time are registered in the storage unit 117 as new original flow rate data (reference point t0, reference value Q0).

  The safety unit 116 also resets the duration measurement timer 115T and the delay prevention determination timer 1142T when the delay interruption prevention flow rate change presence / absence determination unit 1142 determines that there is a substantial flow rate change. At the same time as starting zero, the time at which it is determined that there is a change in flow rate and the flow rate change ΔQ at that time are registered in the storage unit 117 as new original flow rate data (reference point t0, reference value Q0).

  The security unit 116 also resets the duration measurement timer 115T and the decrease direction change determination timer 1143T when the decrease direction change determination flow rate change presence / absence determination unit 1143 determines that there is a substantial flow rate change. At the same time as starting zero, the time at which it is determined that there is a change in flow rate and the flow rate change ΔQ at that time are registered in the storage unit 117 as new original flow rate data (reference point t0, reference value Q0).

  Further, when the average flow rate obtained by the average flow rate calculation unit 111 becomes zero, the security unit 116 clears the duration measurement timer 115T and also determines a determination timer (premature cut prevention determination timer 1141T, delay time). The timer that is operating is cleared among the cutoff prevention determination timer 1142T and the decrease direction change determination timer 1143T).

  In addition, when the safety unit 116 determines that there is a substantial flow rate change by the flow rate change presence / absence determination unit 1141 for the premature disconnection prevention determination or the flow rate change presence / absence determination unit 1143 for the decrease direction change determination, Is a change in flow rate of the proportional control instrument, and when the determination result is a change in flow rate of the proportional control instrument, the premature break prevention determination timer of the determination result acquisition destination determination unit (114 or 115) 1141T or the decreasing direction change determination timer 1143T is cleared.

  The storage unit 117 is means for storing data obtained in the apparatus based on the measurement data obtained by the measurement unit 120.

  Among the controllers 110 as described above, the average flow rate calculation unit 111, the flow rate change detection unit 112, the count unit 113, the flow rate change presence / absence determination unit 114, the duration measurement unit 115, and the security unit 116 are functions of these units. It is realized by a program specialized for realizing the above and an electronic circuit or computer incorporating the program. The storage unit 117 is realized by various types of memories or storage devices.

[Action]
FIG. 4 is a flowchart showing an example of a flow rate change determination process by the controller 110 of the gas meter 100 of the present embodiment having the above-described configuration. The flow of the flow rate change determination process will be described below with reference to FIGS.

[Flow rate change judgment processing]
When the controller 110 acquires the gas flow rate (measurement data) Q flowing through the target gas flow path from the gas flow rate sensor 121 of the measurement unit 120 (YES in S110), the average flow rate calculation unit 111 calculates the average flow rate from the gas flow rate Q. (For example, average flow rate every 30 seconds) Qave is calculated (S120). If the average flow rate Qave is zero (YES in S130), the safety unit 116 clears all operating timers (S140), and then returns to S110.

  When the average flow rate Qave is not zero (NO in S130), the controller 110 registers the average flow rate Qave in the storage unit 117 by the security unit 116 (S150). Then, the flow rate change detection unit 112, the count unit 113, the flow rate change presence / absence determination unit 114, and the security unit 116 are used to prevent premature break flow rate change determination processing (S160), late flow prevention flow rate change determination processing (S170), In addition, three types of individual flow rate change determination processes, namely a decrease direction flow rate change determination process (S180), are performed in parallel. Details of these individual flow rate change determination processes will be described later.

  The security unit 116 of the controller 110 processes the determination result obtained by the individual flow rate change determination processing (S160, S170, S180) and displays it on the display unit 140 (S190). When the elapsed time from the zero start reaches the currently selected safety duration set value according to the flow rate classification of the average flow rate, the duration measuring timer 115T outputs a safety duration over signal indicating that to the safety unit. 116. When the safety unit 116 receives the safety duration over signal from the duration measuring timer 115T (YES in S200), the safety unit 116 gives a cutoff signal to the cutoff valve 130 to block the target gas flow path (S210).

  The security unit 116 obtains an average from a plurality of safety duration setting values individually corresponding to a plurality of flow rate segments until the safety duration over signal from the duration measurement timer 115T is received (NO in S200). By selecting one safety duration setting value according to the flow rate category to which the average flow rate obtained by the flow rate calculation unit 111 belongs, and providing a signal indicating the selected setting value to the duration measurement unit 115, the duration measurement unit 115 The timer 115T is controlled.

[Individual flow rate change judgment processing]
In the following, in the flow rate change determination process shown in FIG. 4, the flow rate change determination process for preventing premature cut (S160), the flow rate change determination process for preventing slow cut (S170), and the decrease direction flow rate change determination process (S180). Each detail will be described sequentially.

[Flow rate change judgment process for premature breakage]
FIG. 5 is a flowchart showing an example of a flow rate change determination process (S160) for preventing premature disconnection in the flow rate change determination process shown in FIG. Hereinafter, the flow of the flow rate change determination process (S160) for preventing premature disconnection will be described with reference to FIGS. 1 to 3 and FIG.

  In the premature disconnection prevention flow rate change determination process (S160), the controller 110 first determines the current average flow rate obtained by the average flow rate calculation unit 111 and the previous average flow rate by the premature disconnection prevention flow rate change detection unit 1121 (FIG. 2). When the difference ΔQ from the average flow rate is compared with the threshold value Qd1 (= 30 L / h) and the average flow rate difference ΔQ is equal to or greater than the threshold value Qd1 (= 30 L / h), that is, the average flow rate is the flow rate before the change. Is changed to a threshold value Qd1 (= 30 L / h) or more (YES in S161), a flow rate change is detected (S162).

  Every time a flow rate change is detected by the premature break prevention determination flow rate change detection unit 1121, the premature cut prevention determination count unit 1131 (FIG. 2) counts the number of flow rate changes (the count value is incremented by 1) (S163). .

  The flow rate change presence / absence determination unit 1141 (FIG. 2) for premature disconnection determination determines whether or not the number of flow rate changes counted by the premature disconnection determination determination unit 1131 has reached a predetermined number (N times) set in advance. Determination (flow rate change presence / absence determination for premature disconnection prevention determination) is made, and if the predetermined number of times (N times) has been reached (YES in S164), it is determined that there is a substantial flow rate change (S165).

  When it is determined that there is a substantial flow rate change by the flow rate change presence / absence determination unit 1141 for the premature disconnection determination, the security unit 116 resets the duration measurement timer 115T and the premature disconnection determination timer 1141T to zero-start. Along with (S166), the time when it is determined that the flow rate has changed and the flow rate change ΔQ at that time are registered in the storage unit 117 as new original flow rate data (reference point t0, reference value Q0) (S167).

[Flow rate change judgment processing for preventing delay]
FIG. 6 is a flowchart illustrating an example of the late flow prevention flow rate change determination process (S170) in the flow rate change determination process shown in FIG. Hereinafter, the flow of the flow rate change determination process (S170) for preventing delay will be described with reference to FIGS. 1 to 3 and FIG.

  In the delay change prevention flow rate change determination process (S170), the controller 110 first determines the current average flow rate obtained by the average flow rate calculation unit 111 and the previous average flow rate by the delay change prevention flow rate change detection unit 1122 (FIG. 2). When the difference ΔQ from the average flow rate is compared with the threshold value Qd2 (= 100 L / h) and the average flow rate difference ΔQ is equal to or greater than the threshold value Qd2 (= 100 L / h), that is, the average flow rate is the flow rate before the change. Is changed to a threshold value Qd2 (= 100 L / h) or more (YES in S171), a flow rate change is detected (S172).

  The late flow prevention determination flow change presence / absence determination unit 1142 (FIG. 2) determines that there is a substantial flow change when the late flow prevention determination flow change detection unit 1122 detects a flow change (S173).

  When it is determined that there is a substantial flow rate change by the delay change prevention flow change determination unit 1142, the security unit 116 resets the duration measurement timer 115T and the delay prevention determination timer 1142T to zero-start. Along with (S174), the time when it is determined that there is a change in flow rate and the flow rate change ΔQ at that time are registered in the storage unit 117 as new original flow rate data (reference point t0, reference value Q0) (S175).

[Decrease direction flow rate change judgment processing]
FIG. 7 is a flowchart showing an example of the decrease direction flow rate change determination process (S180) in the flow rate change determination process shown in FIG. Hereinafter, the flow of the decrease direction flow rate change determination process (S180) will be described with reference to FIGS. 1 to 3 and FIG.

  In the decrease direction flow rate change determination process (S180), the controller 110 firstly calculates the current average flow rate and the previous average flow rate obtained by the average flow rate calculation unit 111 by the decrease direction change determination flow rate change detection unit 1123 (FIG. 2). Is compared with the threshold value Qd3 (= 3%), and the average flow rate difference ΔQ is equal to or greater than the threshold value Qd3 (= 3%), that is, the average flow rate is changed from the flow rate before the change to the threshold value. When it changes by Qd3 (= 3%) or more (YES in S181), the flow rate change is detected (S182).

  Each time a flow rate change is detected by the decrease direction change determination flow rate change detection unit 1123, the decrease direction change determination count unit 1133 (FIG. 2) counts the number of flow rate changes (the count value is incremented by 1) (S183). .

  The decrease direction change determination flow rate change presence / absence determination unit 1143 (FIG. 2) sets the number of flow rate changes counted by the decrease direction change determination count unit 1133 within a predetermined time (X time) set in advance. It is determined whether or not the predetermined number of times (M times) has been reached (determining whether there is a change in flow rate for the decrease direction change determination), and when the predetermined number of times (M times) has been reached within a predetermined time (X time) ( It is determined that there is a substantial change in flow rate (S185).

  When the decrease direction change determination flow rate change presence / absence determination unit 1143 determines that there is a substantial flow rate change, the security unit 116 resets the duration measurement timer 115T and the decrease direction change determination timer 1143T to zero-start. Along with (S186), the time when it is determined that there is a flow rate change and the flow rate change ΔQ at that time are registered in the storage unit 117 as new original flow rate data (reference point t0, reference value Q0) (S187).

[effect]
According to the gas meter 100 of the present embodiment having the configuration and operation as described above, the following effects can be obtained.

[Prevention of early cutting]
According to the present embodiment, the minimum flow rate change value of 30 L / h is used as the threshold value Qd1, the flow rate change of at least 30 L / h is detected, and the number of occurrences is counted. As a determination condition, the flow rate change determination for premature disconnection prevention as shown in FIG. 5 can be performed.

  According to the flow rate change presence / absence determination for this premature cut prevention determination in this embodiment, compared with the conventional method in which only the number of flow rate changes of 3% or 51.82 L / h or more can be counted, (a) in FIG. As shown, the number of flow rate changes of at least 30 L / h or more can be counted. Therefore, even when only a flow rate change of 3% or 51.82 L / h or less occurs, or when the number of occurrences is small or not continuous, as shown in FIG. A change can be detected and it can be determined that there is a substantial flow rate change.

  Here, the example shown in FIG. 8B shows the effect of this embodiment due to the difference in threshold when the predetermined number of times N = 3. According to this embodiment, 30 L / h is obtained. While the above flow rate change is detected three times and it is determined that there is a flow rate change at an early point t1, the conventional threshold value 51.82 L / h has only two flow rate changes at a later point t2. It is not detected and it is not determined that there is a change in flow rate.

  Thus, according to the flow rate change presence / absence determination for premature disconnection determination in the present embodiment, even if a proportional control instrument such as a fan heater, a water heater, a fuel cell, etc. whose flow rate change is moderate during normal operation, It is possible to determine that there is a substantial flow rate change by detecting a flow rate change of the gas flow rate used in the instrument. As a result, whenever a flow rate change occurs in accordance with the user's intention to continue using the instrument, the duration measurement timer can be cleared and the start point of the duration measurement can be updated, so that it is possible to prevent premature disconnection with high reliability.

[Preventing delays]
According to the present embodiment, “a change in flow rate of 100 L / h or more occurs” is detected by detecting a flow rate change of at least 100 L / h using the minimum value of the ignition flow rate of 100 L / h as a threshold value. As a determination condition, it is possible to determine whether or not there is a change in flow rate for the determination of delay of cut as shown in FIG.

  According to the flow rate change presence / absence determination for this slow-down prevention determination in the present embodiment, as shown in FIG. 9, when the gas appliance is forgotten to be turned off, for example, about 70 to 80 L / h, which is below the lowest ignition flow rate level of the gas appliance. Even when only a change in the flow rate occurs, it can be determined that there is a substantial change in the flow rate. As a result, it is possible to prevent the clearing of the duration measurement timer when the gas appliance is forgotten to be turned off, and to perform the necessary gas shut-off for the non-used gas appliance in a timely manner. Can be prevented.

[Flow rate change in decreasing direction can be determined]
According to this embodiment, using a 3% decrease direction change determination value as a threshold value, detecting a flow rate change equal to or greater than the threshold value “3%”, and counting the number of occurrences within a predetermined time. As a determination condition that “a flow rate change of 3% or more occurs more than a predetermined number of times (M times) within a predetermined time (X time)”, a flow rate change presence / absence determination for a decrease direction change determination as shown in FIG. It can be performed.

  According to the flow rate change presence / absence determination for this decrease direction change determination in the present embodiment, the predetermined time (X time) and the predetermined number of times (M times) are appropriately set according to the decreasing tendency of the actual flow rate. As shown in FIG. 10, as a flow rate change from a reference value at a certain reference point, an extremely gentle flow rate that does not cause a flow rate change of 3% or 51.82 L / h or more (for example, 3 times) continuously. Even when it is decreasing, it can be determined that there is a substantial flow rate change. As a result, since the reference value is updated whenever the flow rate changes in the decreasing direction of the proportional control instrument, it is possible to prevent the reference value being used from deviating from the actual flow rate value, and the subsequent determination accuracy can be maintained. Therefore, it is possible to contribute to the realization of safety duration interruption at a timely timing.

[Other Embodiments]
The present invention is not limited to the above-described embodiment, and various other variations are possible within the scope of the present invention. For example, the values shown in the above embodiment as the minimum flow rate change value, the minimum ignition flow rate value, and the decrease direction change judgment value used for detecting the flow rate change are examples based on the statistical data of the flow rate change during use of the gas appliance. Only. That is, the values actually used as the minimum flow rate change value, the minimum ignition flow rate value, and the decrease direction change determination value are appropriately selected according to the type of the target gas appliance and the actual flow rate change during use. Similarly, the specific predetermined time and the predetermined number of times used for determining whether or not the flow rate has changed are also appropriately selected according to the change in the actual flow rate. The configuration of the functional block diagram shown in FIGS. 1 to 3 shows an example of a functional configuration for carrying out the present invention, and a specific hardware configuration and software configuration can be appropriately selected.

  Moreover, although the case where the gas shut-off device of the present invention was incorporated in a gas meter was described in the above embodiment, the gas shut-off device of the present invention may be configured as a device separate from the gas meter. Furthermore, the embodiment of the present invention is not limited to the gas shut-off device, and the flow rate change determination method by the gas shut-off device, and the controller of the gas shut-off device of the present invention as shown in FIG. One embodiment.

The functional block diagram which shows the structure of the gas meter which concerns on one embodiment to which the gas cutoff device of this invention is applied. FIG. 2 is a functional block diagram showing the configuration and data flow of a flow rate change detection unit, a count unit, and a flow rate change presence / absence determination unit shown in FIG. 1. FIG. 2 is a functional block diagram showing the configuration and data flow of a flow rate change presence / absence determination unit and a continuous use time measurement unit shown in FIG. 1. The flowchart which shows an example of the flow volume change determination process by the controller of the gas meter of FIG. 5 is a flowchart showing an example of a flow rate change determination process for preventing premature disconnection in the flow rate change determination process shown in FIG. 4. The flowchart which shows an example of the flow rate change determination process for late | slow cut prevention in the flow rate change determination process shown in FIG. The flowchart which shows an example of the reduction | decrease direction flow volume change determination process in the flow volume change determination process shown in FIG. Explanatory drawing which shows the premature cutting prevention effect by embodiment of FIG. Explanatory drawing which shows the delay prevention effect by embodiment of FIG. Explanatory drawing which shows the effect of the flow volume change determination of the decreasing direction by embodiment of FIG. The figure which shows the safety duration setting value used for the determination at the time of the conventional safety duration exceeding. The figure which shows the example of an actual flow volume change of the fan heater for demonstrating generation | occurrence | production of the premature break in the conventional flow volume change presence-absence determination method. The figure which shows the example of an actual flow volume change of the fan heater for demonstrating generation | occurrence | production of the delay in the conventional flow volume change presence-absence determination method. The figure which shows the example of the flow volume change detection of the proportional control instrument for demonstrating the flow volume change determination in the phenomenon direction in the conventional flow volume change presence-and-absence determination method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Gas meter 110 ... Controller 111 ... Average flow rate calculation part 112 ... Flow rate change detection part 113 ... Count part 114 ... Flow rate change presence determination part 115 ... Duration measurement part 116 ... Security part 117 ... Storage part 120 ... Measurement part 121 ... Gas Flow sensor 122 ... Various sensors 130 ... Shut-off valve 140 ... Display unit 150 ... Communication device

Claims (8)

A shut-off means for shutting off the gas flowing through the target gas flow path and a measuring means for measuring at least the gas flow rate as a physical quantity relating to the gas flowing through the target gas flow path are provided, and the gas flowing through the target gas flow path is monitored and shut off is necessary. In the gas shut-off device that shuts off the target gas flow path by the shut-off means in the case,
Average flow rate calculating means for calculating an average gas flow rate from the measurement data obtained by the measuring means;
It is selected according to the flow rate category to which the average flow rate obtained by the average flow rate calculation means belongs, from among a plurality of preset safety duration values that individually correspond to a plurality of preset flow rate categories. Based on the current setting value, using a timer for duration measurement, a duration measuring means for measuring the duration of the gas flow rate flowing through the target gas flow path,
Security means for shutting off the target gas flow path by the shut-off means when the measurement time by the timer for duration measurement reaches the safety duration set value selected as the current set value;
A flow rate change detecting means for detecting a flow rate change when the average flow rate obtained by the average flow rate calculating means changes by a predetermined threshold value or more with respect to the flow rate before the change;
Counting means for counting the number of flow rate changes detected by the flow rate change detecting means;
A flow rate change presence / absence determining unit that determines that there is a substantial flow rate change when the number of flow rate changes counted by the counting unit reaches a predetermined number of times set in advance;
Comprising storage means for storing data obtained in the apparatus based on measurement data obtained by the measurement means;
The flow rate change detection means uses a flow rate change minimum value representing the minimum level of flow rate change of the proportional control instrument as the preset threshold value, so that the average flow rate is equal to or higher than the flow rate change minimum value from the flow rate before the change. Including a flow rate change detection means for premature cut prevention detection for detecting a flow rate change when changed,
The counting means includes a counting means for early cut prevention determination that counts the number of flow rate changes equal to or greater than the threshold detected by the flow rate change detection means for early cut prevention determination,
The flow rate change presence / absence determination means performs a flow rate change presence / absence determination for premature disconnection determination while measuring a determination time using a timer for premature disconnection determination, and is counted by the count means for determination of early disconnection Including a flow rate change presence / absence determining means for determining that there is a substantial flow rate change when the flow rate change count reaches a preset predetermined number of times,
The security means zero-starts the duration measuring timer and the premature cut prevention timer when the flow rate change presence / absence judgment means for premature cut prevention judgment determines that there is a substantial flow rate change. And a gas shut-off device configured to register the time determined to have a flow rate change and the flow rate at that time in the storage unit as new original flow rate data. The flow rate change presence / absence determining means for determining the premature interruption prevention has reached the predetermined number of times that the flow rate change counted by the counting means for the premature interruption prevention determination has been set within a predetermined time. The gas shut-off device according to claim 1, wherein the gas shut-off device is configured to determine that there is a substantial flow rate change. 2. The gas shut-off device according to claim 1, wherein the flow rate change detection means for determining the premature disconnection uses a value of 30 L / h as the minimum value of the flow rate change. The security means clears the duration measurement timer when the average flow rate obtained by the average flow rate calculation means becomes zero, and if the determination timer is in operation, the timer is also The gas cutoff device according to claim 1, wherein the gas cutoff device is configured to be cleared. The security means determines whether the substantial flow rate change is a flow rate change of the proportional control instrument when the substantial flow rate change is determined by the flow rate change presence / absence determining unit, and the determination result There if a change in flow rate of the proportional control device, the gas cutoff device according to claim 1, characterized in that it is configured to clear a timer for the determination. The average flow rate calculation means, the duration measurement means, the security means, the flow rate change detection means, the count means, and the flow rate change presence / absence determination means have been specialized to realize the functions of these means. The gas cutoff device according to claim 1, wherein the gas cutoff device is realized by a program and an electronic circuit or a computer incorporating the program. The gas flowing through the target gas flow path is monitored by using a blocking means for cutting off the gas flowing through the target gas flow path and a measurement means for measuring at least the gas flow rate as a physical quantity related to the gas flowing through the target gas flow path, and it is necessary to block the gas. In the case of the flow rate change determination method by the gas shut-off device that shuts off the target gas flow path by the shut-off means,
Average flow rate calculating means for calculating an average gas flow rate from the measurement data obtained by the measuring means;
It is selected according to the flow rate category to which the average flow rate obtained by the average flow rate calculation means belongs, from among a plurality of preset safety duration values that individually correspond to a plurality of preset flow rate categories. Based on the current setting value, using a timer for duration measurement, a duration measuring means for measuring the duration of the gas flow rate flowing through the target gas flow path,
Security means for shutting off the target gas flow path by the shut-off means when the measurement time by the timer for duration measurement reaches the safety duration set value selected as the current set value;
A flow rate change detecting means for detecting a flow rate change when the average flow rate obtained by the average flow rate calculating means changes by a predetermined threshold value or more with respect to the flow rate before the change;
Counting means for counting the number of flow rate changes detected by the flow rate change detecting means;
A flow rate change presence / absence determining unit that determines that there is a substantial flow rate change when the number of flow rate changes counted by the counting unit reaches a predetermined number of times set in advance;
Using storage means for storing data obtained in the apparatus based on measurement data obtained by the measurement means,
By using the flow rate change minimum value representing the minimum level of flow rate change of the proportional control instrument as the preset threshold value by the flow rate change detection means, the average flow rate is equal to or higher than the flow rate change minimum value from the flow rate before the change. A flow rate change detection step for prevention of premature cut detection for detecting a flow rate change when changed,
A counting step for premature break prevention determination for counting the number of flow rate changes equal to or greater than the threshold detected in the flow rate change detection step for premature break prevention determination by the counting means;
The flow rate change presence / absence determination means performs a flow rate change presence / absence determination for premature disconnection prevention determination while measuring a determination time using a timer for premature disconnection determination, and is counted in the count step for the determination of early disconnection prevention. A flow rate change presence / absence determination step for premature disconnection determination that determines that there is a substantial flow rate change when the flow rate change number reaches a predetermined number of times set in advance;
If the safety means determines that there is a substantial flow rate change in the flow rate change presence / absence determination step for the premature disconnection prevention determination, the duration measurement timer and the premature disconnection prevention determination timer are zero-started. And a step of registering the time when it is determined that there is a change in flow rate and the flow rate at that time as new original flow rate data in the storage means. A shut-off means for shutting off the gas flowing through the target gas flow path and a measuring means for measuring at least the gas flow rate as a physical quantity relating to the gas flowing through the target gas flow path are provided, and the gas flowing through the target gas flow path is monitored and shut off is necessary. In the controller used in the gas shut-off device that shuts off the target gas flow path by the shut-off means in the case,
Average flow rate calculating means for calculating an average gas flow rate from the measurement data obtained by the measuring means;
It is selected according to the flow rate category to which the average flow rate obtained by the average flow rate calculation means belongs, from among a plurality of preset safety duration values that individually correspond to a plurality of preset flow rate categories. Based on the current setting value, using a timer for duration measurement, a duration measuring means for measuring the duration of the gas flow rate flowing through the target gas flow path,
Security means for shutting off the target gas flow path by the shut-off means when the measurement time by the timer for duration measurement reaches the safety duration set value selected as the current set value;
A flow rate change detecting means for detecting a flow rate change when the average flow rate obtained by the average flow rate calculating means changes by a predetermined threshold value or more with respect to the flow rate before the change;
Counting means for counting the number of flow rate changes detected by the flow rate change detecting means;
A flow rate change presence / absence determining unit that determines that there is a substantial flow rate change when the number of flow rate changes counted by the counting unit reaches a predetermined number of times set in advance;
Comprising storage means for storing data obtained in the apparatus based on measurement data obtained by the measurement means;
The flow rate change detection means uses a flow rate change minimum value representing the minimum level of flow rate change of the proportional control instrument as the preset threshold value, so that the average flow rate is equal to or higher than the flow rate change minimum value from the flow rate before the change. Including a flow rate change detection means for premature cut prevention detection for detecting a flow rate change when changed,
The counting means includes a counting means for early cut prevention determination that counts the number of flow rate changes equal to or greater than the threshold detected by the flow rate change detection means for early cut prevention determination,
The flow rate change presence / absence determination means performs a flow rate change presence / absence determination for premature disconnection determination while measuring a determination time using a timer for premature disconnection determination, and is counted by the count means for determination of early disconnection Including a flow rate change presence / absence determining means for determining that there is a substantial flow rate change when the flow rate change count reaches a preset predetermined number of times,
The security means zero-starts the duration measuring timer and the premature cut prevention timer when the flow rate change presence / absence judgment means for premature cut prevention judgment determines that there is a substantial flow rate change. And a controller for the gas shut-off device, which is configured to register the time when it is determined that the flow rate has changed and the flow rate at that time as new original flow rate data in the storage means.

Images