JP3659735B2 - Gas leak judgment device and gas shut-off device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is provided, for example, for a gas meter provided at a gas supply inlet site to each household, and when an abnormality such as a gas leak occurs in a gas supply line on the lower side of the gas meter, a gas leak signal And a gas cutoff device that shuts off the supply of gas to the gas supply line based on the gas leak information obtained based on such a gas leak determination technique.
[0002]
[Prior art]
Conventionally, in detecting and judging a gas leak, a flow rate measuring means for generating a signal in accordance with the amount of gas passing through the gas meter and a monitoring time series flow rate signal data obtained from the flow rate measuring means are used in the gas supply line. And a leakage signal generating means for generating a leakage signal for detecting and judging a gas leakage and performing a gas shut-off operation.
[0003]
A typical example of such a prior art will be described. A conventional gas shut-off device includes a flow rate change time confirmation means for confirming the occurrence of a flow rate change from the monitoring time series flow rate signal data by the flow rate measurement means, and the flow rate change time point. A duration detecting means for detecting the duration of the on-occurrence flow rate at the time of occurrence confirmed by the confirmation means (referred to as the flow rate difference before and after the flow rate change of a predetermined value or more). The leakage signal is generated when the duration detected by the duration detection means exceeds a preset safety duration cutoff time.
This function will be described with reference to the drawings. As shown in FIG. 20, when the monitoring time series flow rate signal data changes, each change in flow rate occurs in an increased state at the time of device ignition (increase). The flow rate at the time of change (the flow rate at the time of occurrence in the case of increase) is the same due to the relationship between when the flow rate change on the side occurs and when the equipment stops in a declining state (when the change in flow rate on the decrease side occurs) If the time interval between them is too long (exceeding the safety continuous shut-off time) by taking measures when the device is ignited and when the device is stopped, it is determined that a gas leak that needs to be shut off has occurred. Then, it was supposed to be shut off.
FIG. 21 shows the relationship between the generation flow rate and the duration with respect to the generation flow rate. In the area below the solid line (or broken line), it is not determined that the state needs to be shut off. The shut-off operation is performed when the flow rate at the time of occurrence is maintained for a long time.
For example, in the example shown in FIG. 22, the generation flow rate is 1.2 m ³ / h corresponding to the bath, and it is determined that there is a gas leak only after a continuous use state of less than 100 minutes. A gas shut-off operation is performed.
[0004]
In addition, there is a device that determines the device to be used based on the monitoring time-series flow rate signal data and is useful for appropriate shut-off (Japanese Patent Laid-Open No. 3-236864 (in this example, the flow rate and the change flow rate are detected). Then, pattern recognition is performed using a neural network method, and normal ignition patterns, normal combustion patterns, and gas leak patterns are identified separately)). However, with this technology, it is possible to determine whether the device has been ignited in one stage, or whether a two-stage slow ignition that has been set to a desired ignition state through a slow ignition state has been performed. there were.
Here, the slow ignition means that the gas flow rate is maintained for about 0.3 to 10 seconds in the range of about 40 to 90% of the rated gas flow rate of the device in order to prevent explosive ignition of gas devices such as a water heater. It is a gas flow rate control system that performs ignition while.
[0005]
[Problems to be solved by the invention]
Now, the above-described gas leak judgment and shut-off techniques have the following problems.
1 Problem of safety continuous shut-off time reference shut-off of flow rate at maximum occurrence In this method, judgment and shut-off of gas leak is after the safe continuous shut-off time, so the time until judgment and shut-off operation tends to be longer .
2 Limitations of Japanese Patent Laid-Open No. 3-236864 In this method, the flow rate pattern specific to the gas equipment is not specified in advance, and the three types of patterns, the normal ignition pattern, the normal combustion pattern, and the gas leak pattern, are weighted. Therefore, the judgment is easy to be generalized and the probability of misjudgment is high.
In addition, it requires a learning period and labor, and is a probabilistic decision based on limited learning. Become.
[0006]
An object of the present invention is to eliminate such a conventional problem.
[0007]
[Means for Solving the Problems]
According to claim 1 of the present application for achieving the above object, flow rate measuring means for emitting a signal according to the amount of gas passing through a gas meter installed in the gas supply line, and monitoring time obtained from the flow rate measuring means The characteristic configuration of the gas leak judgment device provided with the leak signal generating means for generating the leak signal in the gas supply line based on the series flow rate signal data is as follows.
〔Constitution〕
That is, when the gas equipment provided on the lower side of the gas supply line is normally ignited, it is set in advance based on the recognized normal ignition flow rate pattern, and from the time when the initial flow rate change occurs, which is the basis for direct comparison judgment in the conformity judgment. Storage means for storing a normal ignition judgment reference index including the time and the flow rate at the time of judgment ,
A first leakage signal generating means for performing a determination of conformity of the monitoring flow rate pattern index obtained based on the monitoring time-series flow signal data with respect to a normal ignition determination criterion index, and generating a leakage signal when it does not conform;
Flow rate change time confirmation means for confirming the occurrence of a flow rate change greater than a predetermined value from the monitoring time series flow signal data, and continuation for detecting the duration of the generated flow rate from the occurrence time confirmed by this flow rate change time confirmation means A time detection means,
A second leakage signal generating means for generating a leakage signal when the duration detected by the duration detection means exceeds a preset safety duration cutoff time ;
For use when a gas appliance equipped with an automatic combustion control mechanism that automatically changes the amount of combustion with respect to the combustion load continues normal combustion under automatic combustion control ,
A third leakage signal generating unit is provided for determining whether the monitoring flow rate pattern index obtained based on the monitoring time-series flow signal data is compatible with the normal use determination reference index, and generating the leakage signal when the monitoring flow pattern index is not compatible. .
[Action / Effect]
In the gas leak judgment device having this configuration, the monitoring by the first leak signal generating means and the monitoring by the second leak signal generating means are performed in an overlapping manner. Here, the former monitoring corresponds to the start-up of the gas device, and the latter corresponds to the continuous use state of the gas device. The monitoring by the first leakage signal generating means is performed by determining the suitability of the monitored flow rate pattern index with respect to the normal ignition determination reference index set in advance based on the normal ignition flow rate pattern shown when the gas appliance is normally ignited. Is called. Therefore, this conformity judgment is relatively strict, and if it does not conform, all are judged to be in a leak state to ensure safety.
And, even if a gas leak occurs, the monitoring flow rate pattern index obtained from the monitoring time-series flow signal data conforms to the normal ignition judgment criterion index, and the gas leakage is missed. Even in the configuration of the present application, the flow rate change is separately confirmed by the flow rate change time confirmation unit, and the duration time of the flow rate at the time of occurrence (leakage duration time when leakage occurs) is the duration detection unit. Are sequentially detected. When this time exceeds the safe continuous interruption time, an appropriate leak signal is generated by the second leak signal generating means.
Therefore, in the structure of the present application, the gas leakage is checked at the time of starting up the gas equipment and at least two time points thereafter to ensure the safety. Furthermore, since the first leakage signal generation means makes the determination based on the normal ignition of the gas appliance, the check can be performed in a strict and highly accurate state.
Furthermore, in addition to the first and second leakage signal generation means described above, a third leakage signal generation means is provided. Here, the third leakage signal generating means is intended to correspond to a flow rate pattern that appears when the gas appliance is used in the automatic control state.
That is, in the proportional control state as an example of automatic control, a flow rate change of a predetermined value J or more occurs in a predetermined time range (between t1 and t2 in the example shown in FIG. 15), or the flow rate is Even in the case of monotonous change, a situation occurs in which the flow rate changes by a predetermined value M or more over a predetermined time L or more (in the case shown in FIG. 16). Therefore, by explicitly adopting such a characteristic as a criterion indicator, it is possible to accurately capture the proportional control status and accurately determine the leakage status after retreating.
In this apparatus, triple gas leakage monitoring can be performed to ensure safety.
[0008]
[Configuration / Function / Effect]
In the above-described configuration, it is preferable that a normal ignition determination reference index corresponding to a slow ignition corresponding to a case where the gas appliance is slowly ignited is provided as the normal ignition determination reference index. This configuration relates to claim 2.
Among gas appliances provided in general homes and the like, most of the appliances that use a large amount of gas are those that are subjected to slow ignition control as the ignition operation.
On the other hand, the flow pattern in such a slow ignition control is relatively easy to classify and shows a typical flow pattern, and the elapsed time, flow rate, and flow rate from when a flow rate change of a predetermined amount or more has occurred. Just by grasping the tendency of change, the suitability can be judged. Therefore, as a normal ignition judgment standard index, a normal ignition judgment standard index corresponding to the slow ignition is provided, and the compatibility between this and the monitoring flow rate pattern index is judged, and the slow ignition situation can be appropriately judged. A leak signal can be appropriately generated, which is useful.
The above-mentioned normal ignition judgment reference index is the value corresponding to the elapsed time when the maximum or steady state is reached for the first time after the flow rate change, the flow rate corresponding value when the maximum or steady state is reached for the first time, and then the minimum or increasing start for the first time thereafter. This can be configured as an index having at least one kind of component corresponding to the elapsed time corresponding value, the flow corresponding value when the minimum or the start of increase for the first time, and the tendency of the flow rate change.
[Configuration / Function / Effect]
In the above-described gas leak determination apparatus described above, it is preferable that the first continuous leak signal generating unit extends the safe continuous interruption time when the leak signal is not generated. This configuration relates to claim 4.
Originally, the safety continuation cutoff time is set on the safety side so that even if a gas leak occurs, it is shut off in a relatively short time. However, in this gas leak judgment device, the fact that the gas equipment is in a good ignition state has been confirmed for the time being by the suitability judgment in the first leak signal generation means. Therefore, it is not always necessary to set the safety continuous cutoff time on the safe side. Therefore, when the first leakage signal generating means does not generate the leakage signal, the safety continuous interruption time is extended to eliminate the erroneous interruption due to the safety continuous interruption time.
As a result, it is possible to maintain a good use state of the gas equipment without erroneous interruption.
[Configuration / Function / Effect]
Further, it is preferable that the third continuous leakage signal generating means extends the safe continuous interruption time when the leakage signal is not generated. This configuration relates to claim 5.
As explained earlier, the safety continuation cutoff time is originally set on the safety side so that even if a gas leak occurs, it is shut off in a relatively short time. . However, in this gas leak judgment device, the fact that the gas equipment is in a good use state has been confirmed once by the suitability judgment in the third leak signal generation means. Therefore, it is not always necessary to set the safety continuous cutoff time on the safe side. Therefore, when the third leakage signal generation means does not generate the leakage signal, the safety continuous cutoff time is extended to eliminate the erroneous cutoff due to the safety continuous cutoff time. As a result, it is possible to maintain a good use state of the gas equipment without erroneous interruption.
[Configuration / Function / Effect]
Furthermore, it is preferable that the gas cutoff device is configured to include the gas leakage determination device of the present application and also include a blocking unit that blocks gas in response to generation of a leakage signal generated from the gas leakage determination device. This configuration relates to claim 6.
Based on the signal from the gas leakage judgment device of the present application, the gas can be shut off by the shut-off means with a relatively simple structure.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 19 schematically shows a gas meter 20 provided with the gas shut-off device 1 and a gas device 22 provided on the lower side of the gas supply line 21.
[0010]
In the description, the gas shut-off device 1 will be described. In this gas shut-off device 1, a portion until a leak signal is generated constitutes the gas leak judgment device of the present application.
FIG. 1 is a block diagram of an embodiment of the present invention. The gas shut-off device 1 of this embodiment is monitored based on the flow rate measuring means 2 that emits a signal in a short time unit of about 0.3 seconds or less according to the amount of gas passing through the gas meter, and the signal from the flow rate measuring means 2 A flow rate pattern index calculation means 3 for calculating a flow rate pattern index (consisting of an elapsed time after the flow rate change occurs, a flow rate, and a trend of the flow rate change), and a slow ignition of the gas appliance based on the output from the flow rate pattern index calculation means 3 From the slow ignition pattern recognition means 4 that generates and outputs a leak signal when the flow rate pattern is recognized and the device (device ignition) and leak (gas leak) are judged to be a leak, the flow rate pattern index calculation means 3 When the gas flow pattern by the automatic temperature control (proportional control) of the gas equipment is recognized based on the output of the gas, the equipment (automatic control combustion of the equipment) and the leak (gas leak) are judged, and the leak is judged Automatic control pattern recognition means 5 generates and outputs the leakage signal, and a blocking means 6 for shutting off the gas in accordance with the leakage signal from the slow firing pattern recognition means 4 and the automatic control pattern recognition means 5.
[0011]
Furthermore, the gas shut-off device 1 of the present application includes a flow rate change time confirmation unit 100 for confirming the occurrence of a flow rate change of a predetermined value or more based on the output from the flow rate pattern index calculation unit 3 described above, and the flow rate change. And a duration detecting unit 101 for detecting a duration of the flow rate at the time of occurrence, which is confirmed by the time point confirming unit 100, and a duration of time detected by the duration detecting unit 101 is a preset safety continuous cutoff time. In this case, the safety duration excess determining means 102 for generating a leak signal is provided, and the shut-off means 6 is activated by the leak signal from this means to shut off the gas leak.
[0012]
In the gas shut-off device 1 of the present application, in response to the ignition of the gas equipment, the judgment of the presence or absence of gas leakage by the slow ignition pattern recognition means 4, and then the automatic control pattern recognition means 5 in response to the combustion of the gas equipment. A total of three stages of gas leakage checks are performed based on the determination of the presence or absence of gas leakage and finally the determination of whether or not there is a gas leakage by the safety duration exceeding means 102, and the gas leakage is monitored and used. The safety of the person can be ensured.
Therefore, as shown in FIG. 1, these are called first leakage signal generation means, third leakage signal generation means, and second leakage signal generation means.
Further, a means for generating a leak signal based on a signal from the flow rate measuring means 2 is called a leak signal generating means (see FIG. 1).
[0013]
A storage unit 7 is provided for the slow ignition pattern recognition unit 4, the automatic control pattern recognition unit 5, and the safety duration excess determination unit 102. This storage means 7 is a normal ignition judgment reference index corresponding to slow ignition, which is an index necessary for judgment in the slow ignition pattern recognition means 4, and an index necessary for judgment in the automatic control pattern recognition means 5. A normal use judgment reference index corresponding to proportional control, and a cutoff time correspondence table that is a relational index between the flow rate at the time of occurrence used by the safe duration exceeded determination means 102 and the allowable duration (safety continuous cutoff time) is stored. ing. This table is shown in FIG.
Here, the normal ignition judgment reference index is set in advance based on a normal ignition flow rate pattern that is recognized when a gas device provided on the lower side of the gas supply line is normally ignited, and a flow rate change of a predetermined flow rate or more is recognized. It consists of the elapsed time from the occurrence of the flow rate change, the flow rate at each time point, and the tendency of the flow rate change at each time point.
Furthermore, the normal use judgment reference index is set in advance based on the normal use flow rate pattern that is recognized when the gas equipment provided on the lower side of the gas supply line is normally used, and from the time of occurrence of the flow rate change in which the flow rate change is recognized. The elapsed time, flow rate, and flow rate change tendency.
[0014]
In the following, the configuration of each means and the function thereof will be described sequentially.
1 Flow rate measuring means 2
The flow rate measuring means 2 is a flow meter provided with a gas meter, and is a so-called fluidic meter (with a nozzle portion and a flow channel enlargement portion provided on the lower side of the nozzle portion in the flow channel). It is configured to detect the period of the main flow path change that is generated oscillatingly by the return flow (flow that flows in the flow path direction on the upper side) formed in the flow path expanding portion, and flows through the flow path from this period To obtain the flow rate).
Specifically, the flow rate measuring means 2 has a short time of about 0.3 seconds or less (in order to meet the purpose of the present application, it should have a time resolution of 0.5 seconds or less). A signal can be emitted in units.
A signal measured by the flow rate measuring unit 2 is sent to the flow rate pattern index calculating unit 3.
[0015]
2 Flow pattern index calculation means 3
The flow rate pattern index calculating means 3 is based on a signal from the flow rate measuring means 2 when a flow rate change in which a flow rate change of a predetermined flow rate or more is recognized, an elapsed time since the flow rate change time, and each time point thereafter. The flow rate (basically based on the flow rate before the occurrence of the flow rate change) and the tendency of the flow rate change at each time point are calculated. That is, the monitored flow rate within about 10 to 100 seconds after the rise, such as the maximum and steady flow rate after the gas flow rises, the elapsed time since the flow rate change, and the tendency of the flow rate change at each time point. A pattern index is derived.
Here, the tendency of the flow rate change is an indicator of whether the flow rate is increasing, not changing, or decreasing over time. For example, the trend is based on the relationship of signal data captured over time. Is determined.
This monitored flow rate pattern index is used for recognition / discrimination of the slow ignition pattern recognition means 4, automatic control pattern recognition means 5 and safety duration excess judgment means 102 described later.
[0016]
The generation of the monitoring flow rate pattern index by the flow rate pattern index calculating means 3 is performed on a real time basis. Then, the slow ignition pattern recognition means 4 adopts a configuration in which a compatibility determination with a normal ignition determination reference index corresponding to a slow ignition is performed, and when it does not conform to this, a leakage signal is generated and a shut-off operation can be performed. Has been.
On the other hand, the automatic control pattern recognizing means 5 adopts a configuration in which compatibility judgment with a normal use judgment criterion index corresponding to proportional control is performed, and when it does not conform to this, leakage information is generated and a shut-off operation can be performed. Has been.
[0017]
First, the monitoring of slow ignition will be described.
FIG. 6 shows a shut-off operation scheme in which slow ignition and flow rate duration are monitored.
In this scheme, the flow rate measurement unit 2 performs flow rate measurement (step 1), and the measurement result is processed by the flow rate pattern index calculation unit 3 (step 2). However, in this process, the earliest data measured by the flow rate measuring means 2 and data for a certain time (about 20 to 200 seconds) from the earliest time are stored. Processing is performed on time-series data for a predetermined period. Then, when the change in flow rate is equal to or greater than a predetermined value (A or more), it is determined that a change in flow rate has been recognized (determined that a flow rate during generation has occurred) (step 3). If there is no change from this data, repeat the flow measurement. On the other hand, if a change in the flow rate is recognized, a conformity judgment is made by the slow ignition pattern recognizing means 4 (step 4), and if it is a slow ignition pattern, the safety continuous interruption time is extended (step 5). An interruption judgment is made based on the safety continuous interruption time (step 6). On the other hand, when it is determined in the suitability determination that the slow ignition pattern is not met, a shut-off operation is performed through generation of a leak signal (step 7).
[0018]
The recognition of the slow ignition when such an operation is performed will be described below with a focus on the configuration of the slow ignition pattern recognition means 4.
3 Slow ignition pattern recognition means 4
As shown in FIG. 2, FIG. 3, or FIG. 4, the gas flow rate pattern in the case of slow ignition is a certain range in which the gas flow rate for about 0.3 to 10 seconds immediately after ignition is about 40 to 90% of the rated gas flow rate of the equipment. It becomes maximum, minimum, or steady while being maintained in, and then changes toward a required value according to the rated gas flow rate or use conditions.
On the other hand, when a leak occurs, as shown in FIG. 5, the gas flow rate rises instantaneously and often shows a constant flow rate, and the flow rate pattern similar to that of the slow ignition basically does not appear.
Therefore, by paying attention to the presence or absence of a unique flow rate pattern that appears within about 10 seconds after the start-up due to the slow ignition of the equipment, as shown in the flowcharts of FIGS. And it can be judged reliably.
[0019]
That is, the slow ignition pattern recognizing means 4 makes the judgment of conformity of the monitored flow pattern index output from the flow pattern index calculating means 3 with respect to the normal ignition judgment reference index, so that about 10 seconds after the start-up of the apparatus, The presence or absence of gas leakage is determined, and when it is determined that there is a leakage, a leakage signal is generated and output.
Here, the normal ignition judgment reference index corresponding to the slow ignition pattern is the maximum or steady state for the first time after the flow rate change (Y0) as shown in FIG. 10, FIG. 11 or FIG. 12 and Table 1 (FIG. 23). Elapsed time corresponding values (P1, P2), flow rate corresponding values at these times (Q1, Q2, where the flow rate before the flow rate change is a reference), and the elapsed time when the minimum or start of increase starts for the first time thereafter Corresponding values (P3, P4, P5), corresponding flow rate values (Q3, Q4, Q5, but based on the flow rate before the flow rate change) and flow rate change tendency (increase, no change, decrease) An explicit, simplified indicator of elements. This determination index for the change in flow rate is incorporated as a “determination criterion” in the determination flow of conformity determination described later.
[0020]
Hereinafter, the correspondence between the drawings and the flowchart will be described.
Basically, the configuration shown in FIG. 13 is sufficient for the judgment of conformity. However, in order to further ensure the discrimination between the device and the leak, for example, as shown in the flowchart 14, the maximum is first reached after the gas flow rate rises. A condition determination including a rule for the variation pattern after becoming may be used.
[0021]
Hereinafter, the normal ignition judgment reference index will be described.
3-1 Recognition of slow ignition pattern 1
This situation corresponds to the first stage (J1) of the flowcharts shown in FIGS. 13 and 14, and corresponds to the flow rate change situation shown in FIGS.
That is, within the first set time P1 from the initial flow rate change generation time point Y0 at which an initial flow rate change is recognized, there is a first determination time point Y1 at which the first flow rate decrease tendency appears, and the 1a determination immediately before the first determination time point Y1. When the flow rate X1a is between the first set flow rate Q1 and the second set flow rate Q2 (Q1 <X1a <Q2), it is determined that the mild ignition has occurred (determined to be suitable in the suitability determination). Here, Q1 and Q2 are values within about 40 to 90% of the rated gas flow rate.
[0022]
3-2 Recognition of slow ignition pattern 2
This situation corresponds to the second stage (J2) of FIG. 13 and the third stage (J2) of the flowchart shown in FIG. 14, and corresponds to the flow rate change situation shown in FIG.
That is, the flow rate change tendency is not recognized at the second judgment time point Y2 within the second set time P2 from the initial flow rate change occurrence time point Y0 at which the initial flow rate change is recognized (for example, within ± 1% of the previous flow rate). Only when the first flow rate X1b at the second determination time point Y2 is between the first set flow rate Q1 and the second set flow rate Q2 (Q1 <X1b <Q2), and the second When a tendency to increase the flow rate is recognized at the third determination time point Y3 within the third set time P3 after the determination time point Y2, it is determined that the mild ignition has occurred (determined as being compatible in the suitability determination).
[0023]
3-3 Recognition of slow ignition pattern 3
This situation corresponds to the first and second stages (J1, J3) of the flowchart shown in FIG. 14, and corresponds to the change state of the flow rate shown in FIG.
Within the first set time P1 from the initial flow rate change occurrence time point Y0 at which the flow rate change is recognized at the beginning, there is a first determination time point Y1 at which the first flow rate decrease tendency appears, and the first a determination flow rate X1a immediately before the first determination time point Y1. Is between the first set flow rate Q1 and the second set flow rate Q2 (Q1 <X1a <Q2), the flow rate increases at the fourth determination point Y4 from the first determination point Y1 to the fourth set time P4. And the second judgment flow rate X2, which is the flow rate difference between the first judgment time point Y1 and the fourth judgment time point Y4, is between the third set flow rate Q3 and the fourth set flow rate Q4 (Q3 < It is determined that the slow ignition is occurring in X2 <Q4 (determined that it is suitable in the conformity determination).
[0024]
3-4 Recognition of slow ignition pattern 4
This situation corresponds to the first and second stages (J1, J3) of the flowchart shown in FIG. 14, and corresponds to the change state of the flow rate shown in FIG.
Within the first set time P1 from the initial flow rate change occurrence time point Y0 at which the flow rate change is recognized at the beginning, there is a first determination time point Y1 at which the first flow rate decrease tendency appears, and the first a determination flow rate X1a immediately before the first determination time point Y1. Is between the first set flow rate Q1 and the second set flow rate Q2 (Q1 <X1a <Q2), the flow rate tends to decrease at the fifth determination time Y5 after the fifth set time P5 has elapsed from the first determination time Y1. Is recognized, and when the third determination flow rate X3, which is the flow rate difference between the first determination time point Y1 and the fifth determination time point Y5, is larger than the fifth set flow rate Q5 (Q5 <X3), the slow ignition occurs. It is judged that it is judged that it is suitable in the conformity judgment.
[0025]
In FIG. 14, in the determination in the second stage (J3), pattern recognition is performed before and after the word “or” as described by classifying with the slow ignition patterns 3-3 and 3-4. Separated into different species, these are selectively adapted.
In this way, the generated flow rate is determined to be compatible with a preset normal ignition determination reference index, and if it does not match, it is determined that leakage has occurred and is more reliable than the conventional probabilistic determination method. Device and leakage can be discriminated.
[0026]
In what has been described so far, the slow ignition is set as the monitoring target. However, in addition to this, the proportional control after the slow ignition can be set as the monitoring target. An example of this case will be described with reference to FIG. This figure corresponds to FIG. 6 and shows a shut-off operation scheme in which slow ignition, proportional control and flow rate duration are monitored.
As shown in the figure, compared to FIG. 6, an automatic control pattern (proportional control pattern) identification step (step 8) is added.
Similar to the explanation for identifying the slow ignition pattern described above, this will be described focusing on the configuration of the automatic control pattern identifying means 5.
4 Automatic control pattern recognition means 5
This control becomes a problem, for example, automatic temperature control is a gas flow rate after ignition by a control method such as proportional control in order to stabilize the room temperature or water temperature at a set temperature in a gas appliance such as an air conditioner or a water heater. As shown in FIG. 7, a unique gas flow rate pattern in which the flow rate continuously increases or decreases in units of several seconds to several tens of seconds is exhibited.
On the other hand, the gas flow rate at the time of leakage is basically constant as shown in FIG. 8, and the same fluctuation pattern as in the automatic temperature control does not appear.
Therefore, by paying attention to the presence or absence of a continuous flow rate fluctuation pattern by automatic temperature control of the device, as shown in the flowchart of FIG. 9, it is possible to more reliably determine the device and the leakage together with the recognition of the slow ignition pattern.
The automatic control pattern recognition means 5 determines whether or not the automatic control pattern is recognized by making a conformity determination with respect to the normal use determination reference index corresponding to the proportional control of the monitored flow pattern index output from the flow pattern index calculation means 3. When a leak is determined, a leak signal is generated and output. Here, as shown in FIG. 15 or FIG. 16 and Table 2 (FIG. 24), the normal use determination criterion index is a flow rate fluctuation range in a predetermined fluctuation duration range (t1 to t2) after the gas flow rate is generated. Corresponding value J and monotonous change time corresponding value L.P. It is an explicit index constituted by a monotonically changing flow rate corresponding value M. Here, J, L, and M are values greater than zero.
[0027]
In this means 5, it is determined that the proportional control pattern exists when the index described below is met.
4-1 Proportional control pattern recognition 1
This situation corresponds to the flow chart shown in FIG. 17, and corresponds to the flow rate change situation shown in FIG.
When the difference X4 between the maximum flow rate value Qmax and the minimum flow rate value Qmin is larger than the proportional first set flow rate J within the first set period (t1 to t2) from the initial flow rate change occurrence point Y0 when the flow rate change is recognized. It is determined that the proportional control state is established (J <X4).
[0028]
4-2 Proportional control pattern recognition 2
This situation corresponds to the flow chart shown in FIG. 18, and corresponds to the flow rate change situation shown in FIG.
A monotonous increase or decrease in which the flow rate difference from the previous data is ± 1% or more continues for Y6 (L <Y6) over the second setting period L, and the flow rate change X5 during that period is the proportional second setting. When the flow rate is M or more (M <X5), it is determined that the proportional control state is set.
The slow ignition pattern and the automatic control pattern may be defined by using a cumulative flow rate instead of the elapsed time after the flow rate is generated, and the cumulative flow rate may be calculated based on a signal from the flow rate measuring unit 1 and used for determination. Good.
[0029]
Furthermore, as described so far, the present application is provided with the safety duration excess determining means 102. This will be described below.
5 Safety duration excess discrimination means 102
This means includes a flow rate change time confirmation means 100 for confirming the time of occurrence of a flow rate change from the monitoring time series flow rate signal data, and a continuation of the corresponding generated flow rate from the occurrence time confirmed by the flow rate change time confirmation means 100. Working with the duration detection means 101 for detecting time, a leakage signal is generated when the duration detected by the duration detection means 101 exceeds a preset safety duration cutoff time.
[0030]
This function will be described with reference to the drawings. As shown in FIG. 20, when the monitoring time-series flow rate signal data changes, when the device is ignited in stages with each flow change increasing, Based on the relationship with the equipment stoppage that occurs stepwise in the reduced state, the time interval between them is determined by taking the correspondence between the equipment ignition time (occurrence) and equipment stoppage (disappearance) when the change flow rate is the same. If it is too long (exceeds the safe continuous shut-off time), it is determined that a gas leak that needs to be shut off has occurred, and a leak signal is generated. In FIG. 20 (the same applies to FIG. 22), the internal registration indicates each occurrence flow rate to be monitored. Further, the tables shown in FIG. 20 and FIG. 22 show the tables formed for monitoring the flow rate at the time of occurrence according to the change of the flow rate.
FIG. 21 shows the relationship between the generation flow rate and the duration with respect to the generation flow rate. In the area below the solid line (or broken line), it is not determined that the state needs to be shut off. A leak signal is generated when the on-flow rate is maintained for a long time.
For example, in the example shown in FIG. 22, the generation flow rate is 1.2 m ³ / h corresponding to the bath, and it is determined that there is a gas leak only after a continuous use state of less than 100 minutes. A gas shut-off operation is performed.
Here, as described above, at the stage where the slow ignition is confirmed by the slow ignition pattern recognizing means 4, and further, when the proportional control pattern is confirmed by the automatic control pattern recognizing means 5, the safe continuous interruption time is set. By extending according to the actual use, it is configured to reduce false interruptions that are interrupted by the conventional safety continuous interruption function during use of the device. The solid line in FIG. 21 is the initial set time, and the broken line is the extended time.
[0031]
〔effect〕
According to the present invention, it is possible to recognize and block gas leakage very early and reliably compared to the conventional method, thereby improving the gas safety.
Since the slow ignition pattern and the automatic control pattern in the slow ignition turn recognizing means and the automatic control pattern recognizing means of the present invention can be defined in advance widely corresponding to general gas equipment, a learning process before actual use is unnecessary and learning is performed. The time and labor required for the process can be saved. In addition, when using newly introduced equipment, false interruptions are unlikely to occur.
The discrimination method according to the present invention can be operated with a small-capacity memory and a low-speed CPU that are conventionally installed in meters because the flow rate monitoring time is practically as short as several tens of seconds and the calculation and judgment criteria are not complicated. Is possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing a block configuration of a gas shut-off device. FIG. 2 is a diagram showing an example of a flow pattern in slow ignition. FIG. 3 is a diagram showing an example of a flow pattern in slow ignition. Fig. 5 is a diagram showing an example of a flow pattern in ignition. Fig. 5 is a diagram showing a flow pattern when leakage occurs. FIG. 7 is a diagram showing an example of a flow pattern when proportional control is performed. FIG. 8 is a diagram showing a flow pattern when leakage occurs. FIG. 9 is monitoring slow ignition, proportional control and flow duration. FIG. 10 is an explanatory diagram of a normal ignition judgment criterion index corresponding to FIG. 2; FIG. 11 is an explanatory diagram of a normal ignition judgment criterion index corresponding to FIG. 3; Explanatory drawing of the corresponding normal ignition judgment reference index [FIG. 13] Flowchart of flow pattern conformity judgment in ignition [FIG. 14] Another embodiment of flow pattern conformance judgment flowchart in slow ignition [FIG. 15] Explanatory diagram of normal use judgment reference index corresponding to proportional control [FIG. FIG. 17 is a flowchart for determining the conformity of the flow rate pattern in the proportional control. FIG. 18 is a flowchart for determining the conformity of the flow rate pattern in the proportional control. Another embodiment [FIG. 19] A diagram showing a connection state of a gas meter and a gas appliance. [FIG. 20] An explanatory diagram of an appropriate usage state in which a flow rate duration is monitored. [FIG. FIG. 22 is an explanatory diagram of a shut-off operation whose flow rate duration is monitored. FIG. 23 is a chart showing an index table corresponding to slow ignition. FIG. 24 is an index table corresponding to proportional control. Chart DESCRIPTION OF SYMBOLS
2 Flow measurement means 3 Flow pattern index calculation means 4 Slow ignition pattern recognition means 5 Automatic control pattern recognition means 6 Shut-off means 7 Storage means

Claims (6)

A flow rate measuring means for generating a signal according to the amount of gas passing through a gas meter installed in the gas supply line, and a leak in the gas supply line based on monitoring time series flow rate signal data obtained from the flow rate measuring means. A gas leak determination device including a leak signal generation means for generating a signal,
Time from the initial flow rate change occurrence point that is set in advance based on the normal ignition flow rate pattern that is recognized when the gas equipment provided on the lower side of the gas supply line is normally ignited, and is used as a direct comparison judgment reference in the conformity judgment And storage means for storing a normal ignition judgment reference index including the flow rate at the time of judgment ,
A first leakage signal generating means for generating a leakage signal when the monitoring flow pattern index obtained based on the monitoring time-series flow signal data is determined to be compatible with the normal ignition determination reference index and does not match;
A flow rate change time confirmation means for confirming the occurrence of a flow rate change of a predetermined amount or more from the monitoring time series flow signal data, and a duration time of the generated flow rate from the occurrence time confirmed by the flow rate change time confirmation means is detected. And a duration detection means for
A second leakage signal generating means for generating the leakage signal when the duration detected by the duration detection means exceeds a preset safety duration cutoff time;
For use when a gas appliance equipped with an automatic combustion control mechanism that automatically changes the amount of combustion with respect to the combustion load continues normal combustion under automatic combustion control ,
Gas having a third leakage signal generating means for performing a determination of conformity of the monitoring flow rate pattern index obtained based on the monitoring time-series flow rate signal data with respect to the normal use determination criterion index, and generating the leakage signal when it does not conform Leak determination device.   The gas leak judgment device according to claim 1, further comprising a normal ignition judgment standard index corresponding to a slow ignition corresponding to a case where the gas appliance is lightly ignited as the normal ignition judgment standard index. When the normal ignition judgment reference index is a value corresponding to an elapsed time when it becomes the maximum or steady state for the first time after the change in flow rate, a value corresponding to the flow rate when it becomes the maximum or steady state for the first time, and then when the minimum or increase starts for the first time thereafter The gas leak judgment device according to claim 1 or 2, which is an indicator having at least one kind of a component corresponding to an elapsed time corresponding value, a flow rate corresponding value at the time when the minimum or the start of an increase starts for the first time, and a tendency of a flow rate change . The gas leak judgment device according to any one of claims 1 to 3 , wherein when the first leak signal generation means does not generate the leak signal, the safe continuous interruption time is extended. The gas leak judgment device according to any one of claims 1 to 4 , wherein when the third leak signal generation means does not generate the leak signal, the safe continuous interruption time is extended.   A gas cutoff device comprising the gas leakage judgment device according to any one of claims 1 to 5, and further comprising a cutoff means for blocking gas in response to generation of the leakage signal.

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