JP3324739B2 - Gas shutdown resetting method, gas security device and electronic gas meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas supply method, and more particularly, to a method for detecting a supply abnormality of a gas supplied to a secondary gas system and interrupting the supply of the gas. The present invention relates to a gas shutoff resetting method for detecting that a supply abnormality of a supplied gas has been released and returning the gas supply.

[0002] The present invention also relates to a security device,
In particular, the supply of the gas supplied to the secondary gas system is detected to shut off the supply of the gas, and the supply of the gas supplied to the secondary gas system is detected to be released. The present invention relates to a gas security device for restoring supply of gas.

[0003] The present invention also relates to a gas meter.
The amount of gas used was measured, the supply of gas to the secondary gas system was detected abnormally, and the supply of gas was cut off. The abnormal supply of gas to the secondary gas system was released. The present invention relates to an electronic gas meter that detects a gas flow and returns gas supply.

[0004]

2. Description of the Related Art Conventionally, this kind of gas shut-off / recovery method, a gas security device for executing this method, and an electronic gas meter using such a gas security device are designed to detect an abnormal supply of gas supplied to a secondary gas system. The supply of gas was detected and the supply of gas was shut off, and the shut-off valve was opened and the supply of gas was restored, and the supply abnormality of the gas supplied to the secondary gas system was released during the return safety check time after the return of gas supply It has a function to detect and detect return safety and to shut off leakage.

When the gas supply flow rate is measured using the flow rate pulse generated by the membrane type flow sensor in such a return safety confirmation leak cutoff function, an abnormality is detected in the gas flowing through the secondary gas supply path and the secondary flow is detected. The return safety confirmation time, which is the monitoring period for evaluating whether or not the gas supply abnormality has been resolved after the gas supply is returned after the gas supply to the side gas supply path is shut off, is usually fixed to a fixed value. I was

Specifically, when the above-mentioned membrane type flow sensor is used, the return safety confirmation time is fixed to one minute.
When the flow pulse from the membrane flow sensor is detected within the return safety confirmation time after the return of the gas supply after the gas supply to the secondary gas supply path is cut off, the gas supply abnormality is resolved. As a result, the gas supply to the secondary gas supply passage was shut off.

Here, the secondary gas supply passage connected to the secondary gas supply passage
Whether or not the gas supply abnormality of the secondary gas system has been resolved
For example, if the membrane flow sensor generates one flow pulse (0.7 liter / pulse) for 0.7 liter gas supply flow due to mechanical structure limitations, less than 21 liter / hour This is performed by detecting the gas supply flow rate. That is, in this case, the flow rate pulse is generated from the membrane type flow sensor at a pulse rate of 1 pulse / minute (21 / 0.35 = 1 pulse in 60 seconds)
For a gas supply flow rate of less than 21 liters / hour, a flow pulse is not intermittently received within the 1 minute return safety confirmation time, and in this state, the secondary gas connected to the secondary gas supply path is connected. It was determined that the gas supply abnormality in the system was resolved.

When the above-mentioned membrane type flow sensor is used,
If the gas pressure in the secondary gas supply path drops to 60 ± 40 mmH2O within the return safety confirmation time after the gas supply to the secondary gas supply path is cut off after the gas supply is returned,
Judging that the gas supply abnormality has not been eliminated, the gas supply to the secondary gas supply path is cut off to improve the fail-safe property.

On the other hand, when the above-mentioned ultrasonic flow sensor is used, a gas flow measuring method using the propagation speed of ultrasonic waves is used instead of a mechanical detection method such as a membrane flow sensor, so that the gas supply flow rate can be reduced. The measurement sampling time interval is about several seconds (specifically, 2 seconds), and the gas supply flow rate can be measured instantly compared to the membrane flow sensor. As a result, the return safety confirmation time is also shorter than the membrane flow sensor. Could be shortened to about a few seconds.

[0010]

A return determination as to whether or not the supply abnormality of the gas in the secondary gas system connected to the secondary gas supply passage has been eliminated is made by determining the gas pressure in the secondary gas supply passage or the like. When judging from the return safety check time based on the gas supply flow rate, the return safety check time is determined based on the pipe length, the pipe diameter, and the like of the secondary gas system connected to the secondary gas supply path. In addition, it is necessary to perform individual return optimization by individually optimizing according to the combustion amount of the gas equipment constituting the secondary gas system.

However, such a conventional gas shut-off / recovery method, a gas security device for executing the method,
In an electronic gas meter using such a gas security device, the return safety confirmation time is fixed to a fixed time regardless of whether a membrane flow sensor or an ultrasonic flow sensor is used. When optimizing the determination accuracy of the return determination of the secondary gas system, a pipe volume determined based on a pipe length or a pipe diameter of each secondary gas system connected to the secondary gas supply path, There has been a problem that the return safety confirmation time corresponding to the combustion amount of the gas equipment constituting each secondary gas system is fixed to a constant value at the time of factory shipment.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem. First, an abnormality is detected in a gas flowing in a secondary gas supply passage, and the gas flowing to the secondary gas supply passage is detected. The secondary side downstream from the gas shutoff valve is used to determine the return safety confirmation time, which is a monitoring period for evaluating whether or not the gas supply abnormality has been resolved after the gas supply is restored after the supply is cut off. The correlation between the estimated pipe capacity calculated by estimating the pipe capacity of the secondary gas supply path based on the pipe shape of the gas supply path and the return safety confirmation time is determined in advance, and the measured estimated pipe capacity is A gas shutoff return method for obtaining a return safety confirmation time according to an actual measurement value of an estimated pipe capacity by referring to an actual measurement value and a correlation, based on a pipe shape of a secondary gas supply passage downstream of a gas shutoff valve. Of secondary gas supply passage When the supply of gas in the secondary gas supply path is returned to the estimated pipe capacity calculated as the estimated value and the pressure in the pipe flowing through the secondary gas supply path is monitored, the gas supply abnormality is eliminated. A step of previously obtaining a correlation of the return safety confirmation time, which is a monitoring period for evaluating whether or not the gas supply path, and temporarily operating the gas supply valve by operating a gas cutoff valve provided in the gas supply path. A pressure relaxation time, which is a time required for the gas pressure in the secondary gas supply path to be reduced by a pressure difference of a preset gas pressure constant during the shutoff, A step of calculating an estimated pipe capacity by calculating a flowing gas supply flow rate and a pressure relaxation time; and a step of calculating an optimum return safety confirmation time for a secondary gas supply path with reference to the estimated pipe capacity and correlation. Depending on the configuration, whether using a membrane type flow sensor or using an ultrasonic type flow sensor, the pipe length and pipe diameter of each secondary gas system connected to the secondary gas supply path, etc. Optimum return safety for each secondary gas supply path by referring to the piping volume determined based on the above, the estimated piping capacity and correlation corresponding to the combustion amount of the gas equipment constituting each secondary gas system The confirmation time is individually obtained, and the accuracy of the judgment of the return judgment of the secondary gas system is optimized based on the optimized return safety confirmation time. As a result, the return safety confirmation time is optimized. That is the task.

Secondly, is it possible to detect whether an abnormality has been detected in the gas flowing in the secondary gas supply passage and to eliminate the gas supply abnormality after the gas supply is restored after the gas supply to the secondary gas supply passage is interrupted. Estimation of the pipe capacity of the secondary gas supply path based on the pipe shape of the secondary gas supply path downstream of the gas shut-off valve when determining the return safety confirmation time, which is a monitoring period for evaluating whether or not the secondary gas supply path has been evaluated. Means for previously obtaining a correlation between the estimated pipe capacity calculated as a value and the return safety confirmation time,
Means for applying a measured actual value of the estimated pipe capacity to the correlation to obtain a return safety confirmation time corresponding to the actual value of the estimated pipe capacity, the secondary side being downstream of the gas shutoff valve. The gas supply in the secondary gas supply path is returned to the estimated pipe capacity calculated by estimating the pipe capacity of the secondary gas supply path based on the pipe shape of the gas supply path, and the secondary gas supply is performed. A table that holds in advance a correlation of a return safety confirmation time, which is a monitoring period for evaluating whether or not a gas supply abnormality has been eliminated when monitoring the pressure in the pipe flowing in the path, and provided in the gas supply path. The gas pressure in the secondary gas supply path is reduced by a pressure difference of a preset gas pressure constant while the supply of gas in the gas supply path is temporarily shut off by operating the gas shutoff valve. Pipe capacity estimating means for calculating an estimated pipe capacity by calculating a pressure relaxation time, which is a time required until, and a gas supply flow rate and a pressure relaxation time flowing through the secondary gas supply path at that time; A return safety confirmation time calculating means for obtaining an optimum return safety confirmation time for the secondary gas supply path, wherein the pipe capacity estimating means supplies the gas flowing through the secondary gas supply path when the pressure relaxation time is measured. The estimated flow capacity is calculated by calculating the flow rate and the pressure relaxation time, and the return safety confirmation time calculation means calculates the estimated pipe capacity obtained by the pipe capacity estimation means to the correlation previously obtained by the first means. It is configured to determine the return safety confirmation time corresponding to the pressure relaxation time obtained by applying the pipe capacity estimation means, so that the membrane type flow sensor can be used or the ultrasonic type flow sensor can be used. In each case, the pipe volume determined based on the pipe length, pipe diameter, etc. of each secondary gas system connected to the secondary gas supply path, and the configuration of each secondary gas system Apply the estimated pipe capacity corresponding to the amount of combustion of the gas equipment
The optimum return safety confirmation time is individually obtained for each secondary gas supply path, and the accuracy of the return determination of the secondary gas system is optimized based on the optimized return safety confirmation time. As a result, the object is to optimize the return safety confirmation time.

Third, the amount of gas to be used is measured, the supply of gas to the secondary gas system is detected, and the supply of gas is shut off. In an electronic gas meter that detects that the supply abnormality has been released and resumes gas supply, combustion control that promotes the combustion operation by operating the above-described gas security device and a gas device connected to the gas supply path and having a small combustion amount. A gas pressure measuring sensor for obtaining a gas supply flow rate during combustion of a gas appliance having a small combustion amount as a reference gas supply flow rate, and obtaining a gas pressure of a secondary gas supply path at that time as a reference gas pressure; A gas shut-off valve for operating a gas shut-off valve provided in the supply passage to temporarily shut off gas supply in the gas supply passage, wherein the combustion control means controls a gas supply flow rate flowing to the secondary gas supply passage. Return cheap By monitoring only the confirmation time and evaluating whether or not the gas supply abnormality has been eliminated, whether using a membrane type flow sensor or using an ultrasonic type flow sensor, Corresponds to the pipe volume determined based on the pipe length, pipe diameter, etc. of each secondary gas system connected to the secondary gas supply path, and the amount of combustion of the gas equipment constituting each secondary gas system The estimated estimated pipe capacity is applied to a table to individually determine an optimal return safety confirmation time for each secondary gas supply path, and the secondary gas system is restored based on the optimized return safety confirmation time. Optimizing the accuracy of the judgment, as a result,
The task is to optimize the return safety confirmation time.

[0015]

Means for Solving the Problems In order to solve the above problems, the invention according to claim 1 made according to the present invention is directed to a gas supply to a secondary gas system (13B, 30, ..., 30). The supply of gas is interrupted by detecting the supply abnormality, and the supply of gas is restored by detecting that the supply abnormality of the gas supplied to the secondary gas system (13B, 30,..., 30) is released. In the gas shut-off and resetting method, the secondary gas supply path 1
An abnormality is detected in the gas flowing to 3B and the secondary gas supply path 1
When the return safety confirmation time T, which is a monitoring period for evaluating whether or not the gas supply abnormality has been resolved after the return of the gas supply after the gas supply to 3B is shut off, is determined, the gas shutoff valve 26 is used. Downstream secondary gas supply passage 13
The correlation between the estimated pipe capacity k calculated as an estimated value of the pipe capacity of the secondary gas supply passage 13B based on the pipe shape of B and the return safety confirmation time T is obtained in advance, and the measured estimation is performed. The actual measured value of the pipe capacity k is referred to the correlation to determine the return safety confirmation time T according to the measured value of the estimated pipe capacity k.

According to the first aspect of the present invention, regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used, the secondary gas supply path 13B connected to the secondary gas supply passage 13B is used. A pipe volume determined based on a pipe length, a pipe diameter, and the like for each of the secondary gas systems (13B, 30, ..., 30),
, 30 constituting the respective secondary gas systems (13B, 30,..., 30), with reference to the estimated pipe capacity k and the correlation corresponding to the combustion amount of the secondary gas supply path 13
The optimum return safety confirmation time T can be obtained individually for each B. Based on the optimized return safety confirmation time T, the secondary gas system (13B, 30,
, 30) can be optimized, and as a result, the return safety confirmation time T can be optimized.

According to a second aspect of the present invention for solving the above-mentioned problems, in the gas shut-off return method according to the first aspect, the secondary gas supply downstream of the gas shut-off valve 26 is provided. The supply of gas in the secondary gas supply path 13B is returned to the estimated pipe capacity k calculated by estimating the pipe capacity of the secondary gas supply path 13B based on the pipe shape of the path 13B. Then, when monitoring the pressure P in the pipe flowing through the secondary gas supply passage 13B, the correlation between the return safety confirmation time T, which is a monitoring period for evaluating whether or not the gas supply abnormality has been eliminated, is shown. In the process of obtaining in advance, the secondary gas supply passage 13B is operated while the gas supply valve 13 provided in the gas supply passage 13 is operated and the gas supply in the gas supply passage 13 is temporarily interrupted. Relaxation time ΔT, which is the time required for the gas pressure P to decrease by the pressure difference of the preset gas pressure P constant ΔP, and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time. To calculate the estimated pipe capacity k and the step of calculating the optimum return safety confirmation time T for the secondary gas supply path 13B by referring to the estimated pipe capacity k and the correlation. Logical configuration.

According to the invention described in claim 2, according to claim 1,
In addition to the effects described in (1), the pressure relaxation time ΔT and the secondary gas supply path 1 at that time are obtained regardless of whether the membrane type flow sensor or the ultrasonic type flow sensor is used.
Since the estimated pipe capacity k is obtained by calculating the gas supply flow rate Q flowing to the 3B and the optimum return safety confirmation time T for the secondary gas supply path 13B is obtained by referring to the estimated pipe capacity k and the correlation. , A pipe volume determined based on a pipe length, a pipe diameter, and the like of each secondary gas system (13B, 30, ..., 30) connected to the secondary gas supply path 13B, and each secondary gas system Gas equipment 3 constituting (13B, 30,..., 30)
It is possible to refer to the estimated pipe capacity k and the correlation corresponding to the combustion amount of 0,. Will be able to That is, it is possible to optimize the determination accuracy of the return determination of the secondary gas system (13B, 30,..., 30) based on the optimized return safety confirmation time T. As a result, the return safety confirmation time T can be optimized.

According to a third aspect of the present invention, which is achieved by the present invention in order to solve the above-mentioned problem, in the gas shut-off / return method according to the second aspect, a gas appliance 30 connected to the gas supply path 13 and having a small combustion amount is provided. ,.., 30 are operated to promote the combustion operation.

According to the invention of claim 3, according to claim 2,
In addition to the effects described in the above, in either case of using the membrane type flow sensor or the case of using the ultrasonic type flow sensor, the gas appliances 30,... Since the pressure relaxation time ΔT is obtained in the operated state, the gas supply flow rate Q caused by the minute leakage and the minimum gas supply flow rate Q of the combustion devices 30,..., 30 are connected to the secondary gas supply passage 13B. Secondary gas system (13
B, 30,..., 30), the pipe volume determined based on the pipe length, the pipe diameter, etc., and the secondary gas systems (13B, 3B).
0,..., 30) can be determined according to the combustion amount of the gas appliances 30,. Further, the pressure relaxation time ΔT obtained in correspondence with the gas appliances 30,..., 30 having a small combustion amount and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time are calculated. The estimated pipe capacity k corresponding to the equipment 30,..., 30 is determined, and the estimated pipe capacity k and the gas equipment 30,
, 30, the optimum return safety confirmation time T for the secondary gas supply path 13B corresponding to the gas appliances 30,. A pipe volume determined based on a pipe length, a pipe diameter, or the like of each of the secondary gas systems (13B, 30,..., 30) connected to the secondary gas supply path 13B, and each secondary gas system (1
3B, 30,..., 30), it is possible to refer to the estimated pipe capacity k and the correlation corresponding to the gas appliances 30,. The gas appliances 30,.
The optimum return safety confirmation time T corresponding to 0 can be individually obtained. That is, the return determination of the secondary gas system (13B, 30,..., 30) is performed based on the return safety confirmation time T optimized for the gas appliances 30,. It is possible to optimize the determination accuracy, and as a result, it is possible to optimize the return safety confirmation time T.

According to a fourth aspect of the present invention, which is made by the present invention to solve the above-mentioned problem, in the gas shut-off / return method according to the third aspect, the gas appliance 3 having a small combustion amount is used.
A third step of obtaining the gas supply flow rate Q during combustion of 0,..., 30 as the reference gas supply flow rate Q0, and obtaining the gas pressure P of the secondary gas supply path 13B at that time as the reference gas pressure P0. Logical configuration.

According to the invention described in claim 4, according to claim 3,
In addition to the effects described in the above, the gas appliances 30,..., 30 connected to the gas supply path 13 and having a small combustion amount are used regardless of whether the membrane type flow sensor or the ultrasonic type flow sensor is used. In the operating state, the gas pressure P of the secondary gas supply path 13B at that time is determined as a reference gas pressure P0, and this reference gas pressure P0 is used as a criterion for determining a gas pressure drop caused by the gas supply flow rate Q at the time of a small leak. , And the time required for the gas pressure P to decrease by a predetermined pressure from the reference gas pressure P0 is determined as the pressure relaxation time ΔT. Therefore, the gas supply flow rate Q caused by the minute leakage and the combustion equipment 30,. The minimum gas flow rate P0 of the secondary gas system (13B, 30,...) Connected to the secondary gas supply passage 13B.
, 30), the pipe volume determined based on the pipe length, the pipe diameter, etc., and the secondary gas systems (13B, 30,.
0) can be determined in accordance with the amount of combustion of the gas appliances 30, ..., 30. Further, the pressure relaxation time ΔT obtained in correspondence with the gas appliances 30,..., 30 having a small combustion amount and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time are calculated. Equipment 30,
, 30, the estimated pipe capacity k is determined, and the gas equipment 3 having a small combustion amount is referred to by referring to the estimated pipe capacity k and the correlation corresponding to the gas equipments 30,.
Since the optimum return safety confirmation time T is determined for the secondary gas supply path 13B corresponding to 0,..., 30, the secondary gas system (13B, 3) connected to the secondary gas supply path 13B
0,..., 30), the pipe volume determined based on the pipe length, the pipe diameter, and the like, and the secondary gas systems (13B, 30,
, 30), the gas appliances 30 with a small combustion amount,
, 30 can be referred to, and as a result, the secondary gas supply path 13 can be referred to.
Gas supply flow rate Q due to micro leak and combustion equipment 3 for each B
The optimum return safety confirmation time T corresponding to the minimum gas flow rate P0 of 0,..., 30 or the gas appliances 30,. That is, based on the return safety confirmation time T optimized in accordance with the gas equipment 30,..., 30 having such a small combustion amount or the gas supply flow rate Q resulting from the minute leakage, the secondary gas system (13B, 30,..., 30) can be optimized, and as a result, the return safety confirmation time T can be optimized.

According to a fifth aspect of the present invention for solving the above-mentioned problem, according to the third aspect of the present invention, the gas shut-off valve 26 provided in the gas supply passage 13 is replaced with the gas shut-off valve 26. A logical configuration having a fourth step of operating and temporarily interrupting the supply of gas in the gas supply path 13 was adopted.

According to the invention described in claim 5, according to claim 3,
In addition to the effects described in the above, in either case of using a membrane type flow sensor or using an ultrasonic type flow sensor, the gas shutoff valve 26 provided in the gas supply path 13 is operated to supply the gas. By temporarily shutting off the supply of gas in the passage 13, the secondary gas supply passage 13B connected to the gas supply passage 13 and operating the gas equipment 30,. Can be obtained as the reference gas pressure P0. The reference gas pressure P0 obtained in this manner is used as a criterion for determining the gas pressure drop caused by the gas supply flow rate Q at the time of a small leak, and the descent time until the gas pressure P decreases from the reference gas pressure P0 by a predetermined pressure. Is determined as the pressure relaxation time ΔT, the gas supply flow rate Q resulting from the minute leakage and the minimum gas flow rate P0 of the combustion devices 30,..., 30 are calculated by using the secondary gas supply path 13B connected to the secondary gas supply path 13B. Line (13
B, 30,..., 30), the pipe volume determined based on the pipe length, the pipe diameter, etc., and the secondary gas systems (13B, 3B).
0,..., 30) can be determined according to the combustion amount of the gas appliances 30,. Further, the pressure relaxation time ΔT obtained in correspondence with the gas appliances 30,..., 30 having a small combustion amount and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time are calculated. The estimated pipe capacity k corresponding to the equipment 30,..., 30 is determined, and the estimated pipe capacity k and the gas equipment 30,
, 30, the optimum return safety confirmation time T for the secondary gas supply path 13B corresponding to the gas appliances 30,. A pipe volume determined based on a pipe length, a pipe diameter, or the like of each of the secondary gas systems (13B, 30,..., 30) connected to the secondary gas supply path 13B, and each secondary gas system (1
3B, 30,..., 30), it is possible to refer to the estimated pipe capacity k and the correlation corresponding to the gas appliances 30,. The optimal return safety confirmation time corresponding to the gas supply flow rate Q caused by the minute leak and the minimum gas flow rate P0 of the combustion equipment 30,... 30 or the gas equipment 30,. T can be obtained individually. That is, based on the return safety confirmation time T optimized in accordance with the gas equipment 30,..., 30 having such a small combustion amount or the gas supply flow rate Q caused by the minute leakage, the secondary gas system (13B, 30, ..., 3
It is possible to optimize the determination accuracy of the return determination of 0), and as a result, it is possible to optimize the return safety confirmation time T.

According to a sixth aspect of the present invention, which is made by the present invention to solve the above-mentioned problems, in the gas shut-off resetting method according to any one of the second to fifth aspects, the pressure relaxation time ΔT is measured. At this time, a logical configuration including a fifth step of calculating the estimated pipe capacity k at the time of executing the fourth step by calculating the gas supply flow rate Q flowing through the secondary-side gas supply passage 13B.

According to the invention described in claim 6, according to claim 2,
6. In addition to the effects described in any one of (5) to (5), the gas shut-off valve provided in the gas supply path 13 regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used. By operating the gas supply 26, the supply of gas in the gas supply path 13 is temporarily cut off, so that the gas appliances 30,.
0 and the secondary gas supply passage 13 at that time
The gas pressure P of B can be obtained as the reference gas pressure P0. The reference gas pressure P0 obtained in this manner is used as a criterion for determining a gas pressure drop caused by the gas supply flow rate Q at the time of a small leak, and a descent time until the gas pressure P decreases from the reference gas pressure P0 by a predetermined pressure. Is calculated as the pressure relaxation time ΔT, and the estimated pipe capacity k is calculated by calculating the gas supply flow rate Q flowing through the secondary gas supply passage 13B and the pressure relaxation time ΔT when measuring the pressure relaxation time ΔT. The estimated pipe capacity k corresponding to the gas supply flow rate Q resulting from the leakage and the minimum gas flow rate P0 of the combustion equipment 30, ..., 30 is connected to the secondary side gas supply path 13B.
The pipe volume determined based on the pipe length and the pipe diameter for each of the secondary gas systems (13B, 30,..., 30) and the gas constituting each of the secondary gas systems (13B, 30,..., 30) .., 30 can be determined in accordance with the amount of combustion. Further, the pressure relaxation time ΔT determined in correspondence with the gas appliances 30,..., 30 with a small combustion amount and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time are calculated. , 30 and the estimated pipe capacity k corresponding to the minimum gas flow rate P0,
30, the optimum return safety confirmation time T for the secondary gas supply path 13B corresponding to the gas appliances 30,..., 30 having a small combustion amount with reference to the correlation corresponding to the minimum gas flow rate P0 of 0,. , The pipe volume determined based on the pipe length, the pipe diameter, etc. of each secondary gas system (13B, 30,..., 30) connected to the secondary gas supply path 13B,
An estimated pipe corresponding to the lowest gas flow rate P0 of the combustion equipment 30,..., 30 corresponding to the gas equipment 30,..., 30 with a small amount of combustion constituting each secondary gas system (13B, 30,. The capacity k and the correlation can be referred to,
As a result, for each of the secondary gas supply passages 13B, the gas supply flow rate Q caused by the minute leak and the minimum gas flow rate P0 of the combustion equipments 30,... 30, or the gas equipments 30,. Optimal return safety confirmation time T corresponding to
Can be obtained individually. That is, based on the return safety confirmation time T optimized in accordance with the gas equipment 30,..., 30 having such a small combustion amount or the gas supply flow rate Q resulting from the minute leakage, the secondary gas system (13B, 30,..., 30) can be optimized, and as a result, the return safety confirmation time T can be optimized.

According to a seventh aspect of the present invention, which is made by the present invention to solve the above-mentioned problems, in the gas shut-off and return method according to the sixth aspect, the correlation obtained in advance in the first step is the same as that in the first step. The estimated pipe capacity k obtained in the fifth step
And a sixth step of obtaining the return safety confirmation time T corresponding to the pressure relaxation time ΔT obtained in the fifth step.

According to the invention described in claim 7, according to claim 6,
Has the same effect as the effect described in (1).

[0029] In order to solve the above-mentioned problem, the present invention according to claim 8 according to the present invention is directed to the gas shut-off / return method according to any one of claims 2 to 7, wherein the secondary gas supply passage is provided. A seventh step of monitoring the gas supply flow rate Q flowing to the 13B for the return safety confirmation time T and evaluating whether or not the gas supply abnormality has been eliminated is provided.

According to the invention described in claim 8, according to claim 2,
In addition to the effects described in any one of (1) to (7), in either case of using a membrane type flow sensor or using an ultrasonic type flow sensor, the secondary gas supply is performed at the time of measuring the pressure relaxation time ΔT. Since the estimated pipe capacity k is obtained by calculating the gas supply flow rate Q flowing through the passage 13B and the pressure relaxation time ΔT, the gas supply flow rate Q caused by the minute leakage and the combustion equipment 3
The estimated pipe capacity k corresponding to the minimum gas flow rate P0 of 0,..., 30 is determined by the pipe length and the pipe for each secondary gas system (13B, 30,..., 30) connected to the secondary gas supply path 13B. The pipe volume determined based on the diameter and the like, and the gas equipment 30,
, 30 and the pressure relaxation time ΔT determined for the gas appliances 30,..., 30 having a small combustion amount, and the gas flowing through the secondary gas supply passage 13B at that time. By calculating the supply flow rate Q and the combustion equipment 30, ...,
An estimated pipe capacity k corresponding to the minimum gas flow rate P0 of 30 is determined, and the gas equipment 30 with a small combustion amount is referred to by referring to the estimated pipe capacity k and the correlation corresponding to the minimum gas flow rate P0 of the combustion equipment 30,. ,.., 30 are determined for the secondary safety gas supply path 13B. A pipe volume determined based on a pipe length, a pipe diameter, and the like for each of the secondary gas systems (13B, 30,..., 30) connected to the secondary gas supply path 13B, and each of the secondary gas systems ( 1
3B, 30,..., 30) correspond to the gas appliances 30,.
It is possible to refer to the estimated pipe capacity k and the correlation corresponding to the minimum gas flow rate P0 of 0, and as a result, the gas supply flow rate Q caused by the minute leak and the combustion equipment 30, ... for each secondary gas supply path 13B. , 30 corresponding to the minimum gas flow rate P0 or the gas appliances 30,..., 30 with a small amount of combustion can be individually determined. That is, the secondary gas supply path 13B
The gas supply flow rate Q flowing through the apparatus is monitored for an optimum time based on the return safety confirmation time T, and the accuracy of the determination of whether or not the gas supply abnormality has been eliminated can be optimized.

In order to solve the above-mentioned problem, the invention according to claim 9 made according to the present invention provides a secondary gas system (13).
B, 30,..., 30), the supply of gas is interrupted by detecting a supply abnormality of the gas supplied to the secondary gas system (13).
B, 30,..., 30), in the gas security device 10 that detects that the supply abnormality of the gas supplied to the gas supply device has been released and recovers the supply of the gas, the gas flowing through the secondary gas supply passage 13B has an abnormality. A return safety confirmation time T, which is a monitoring period for evaluating whether or not the gas supply abnormality has been resolved after the return of the gas supply after the detected and supply of the gas to the secondary gas supply passage 13B is cut off, is determined. In this case, the estimated pipe capacity k calculated by estimating the pipe capacity of the secondary gas supply path 13B based on the pipe shape of the secondary gas supply path 13B downstream of the gas shutoff valve 26 and the return. Means for previously obtaining a correlation with the safety confirmation time T, and applying the measured value of the measured estimated piping capacity k to the correlation to determine the return safety confirmation time T according to the measured value of the estimated piping capacity k. Request And the hardware configuration and a means.

According to the ninth aspect of the present invention, regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used, the secondary gas supply path 13B connected to the secondary gas supply passage 13B is used. A pipe volume determined based on a pipe length, a pipe diameter, and the like for each of the secondary gas systems (13B, 30,..., 30);
, 30 constituting the respective secondary gas systems (13B, 30,..., 30), with reference to the estimated pipe capacity k and the correlation corresponding to the combustion amount of the secondary gas supply path 13
The optimum return safety confirmation time T can be obtained individually for each B. Based on the optimized return safety confirmation time T, the secondary gas system (13B, 30,
, 30) can be optimized, and as a result, the return safety confirmation time T can be optimized.

According to a tenth aspect of the present invention for solving the above-mentioned problem, in the gas security apparatus 10 according to the ninth aspect, the secondary gas supply downstream of the gas shutoff valve 26 is provided. The supply of gas in the secondary gas supply path 13B is returned to the estimated pipe capacity k calculated by estimating the pipe capacity of the secondary gas supply path 13B based on the pipe shape of the path 13B. Then, when monitoring the pressure P in the pipe flowing through the secondary gas supply passage 13B, the correlation between the return safety confirmation time T, which is a monitoring period for evaluating whether or not the gas supply abnormality has been eliminated, is shown. The table 11 held in advance, and the gas shutoff valve 26 provided in the gas supply path 13 is operated to temporarily shut off the supply of gas in the gas supply path 13, and the secondary A pressure relaxation time ΔT which is a time required until the gas pressure P in the gas supply path 13B decreases by a pressure difference of a preset gas pressure P constant ΔP, and a gas flowing through the secondary side gas supply path 13B at that time. A pipe capacity estimating means 12 for calculating the estimated pipe capacity k by calculating a supply flow rate Q; and applying the estimated pipe capacity k to the table 11 to confirm the return safety optimum for the secondary gas supply passage 13B. A hardware configuration having a return safety confirmation time calculation means 14 for obtaining the time T is adopted.

According to the tenth aspect of the present invention, in addition to the effect of the ninth aspect, even if a membrane type flow sensor or an ultrasonic type flow sensor is used, the piping It is possible to calculate the estimated pipe capacity k by using the pipe capacity estimating means 12 by calculating the pressure relaxation time ΔT obtained by the capacity estimating means 12 and the gas supply flow rate Q flowing through the secondary gas supply path 13B at that time. This makes it possible to determine the optimum return safety confirmation time T for the secondary gas supply path 13B by using the return safety confirmation time calculation means 14 with reference to the estimated pipe capacity k and the table 11. 2 connected to the secondary gas supply path 13B
The pipe volume determined based on the pipe length and the pipe diameter of each secondary gas system (13B, 30, ..., 30), and the gas constituting each secondary gas system (13B, 30, ..., 30) It is possible to refer to the estimated pipe capacity k and the table 11 corresponding to the combustion amount of the devices 30,.
The optimum return safety confirmation time T can be individually obtained for each of the secondary gas supply paths 13B. That is, it is possible to optimize the determination accuracy of the return determination of the secondary gas system (13B, 30,..., 30) based on the optimized return safety confirmation time T. As a result, the return safety confirmation time T can be optimized.

According to an eleventh aspect of the present invention for solving the above-mentioned problems, in the gas security apparatus 10 according to the tenth aspect, the pipe capacity estimating means 12 is configured to determine whether the pressure relaxation time ΔT The hardware configuration is such that the estimated pipe capacity k is obtained by calculating the gas supply flow rate Q flowing through the secondary gas supply path 13B during measurement.

According to the eleventh aspect of the present invention, in addition to the effect of the tenth aspect, even when using a membrane type flow sensor or using an ultrasonic type flow sensor, the gas The gas shutoff valve 2 provided in the supply path 13
6 is operated to temporarily cut off the supply of gas in the gas supply path 13, so that the gas appliances 30,... The gas pressure P of the secondary gas supply passage 13B can be obtained as the reference gas pressure P0. The reference gas pressure P0 obtained in this manner is used as a criterion for determining a gas pressure drop caused by the gas supply flow rate Q at the time of a small leak, and a descent time until the gas pressure P decreases from the reference gas pressure P0 by a predetermined pressure. Is determined by the pipe capacity estimating means 12 as the pressure relaxation time ΔT, and the gas supply flow rate Q flowing through the secondary gas supply passage 13B and the pressure relaxation time ΔT when the pressure relaxation time ΔT determined by the pipe capacity estimating means 12 is measured. Is calculated by the pipe capacity estimating means 12 to obtain the estimated pipe capacity k. Therefore, the estimated pipe capacity k corresponding to the gas supply flow rate Q caused by the minute leakage and the minimum gas flow rate P0 of the combustion equipment 30,. , Secondary gas supply path 1
The secondary gas system (13B, 30, ..., 3B) connected to 3B
30) A pipe volume determined based on a pipe length, a pipe diameter, etc. for each secondary gas system (13B, 30,..., 30)
Can be determined in accordance with the amount of combustion of the gas appliances 30,. Further, the pressure relaxation time ΔT determined for the gas appliances 30,...
And the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time are calculated by the pipe capacity estimating means 12 to calculate the combustion equipment 3
The estimated pipe capacity k corresponding to the minimum gas flow rate P0 of 0,..., 30 is calculated, and the estimated pipe capacity k and the combustion equipment 30,.
The optimum return safety confirmation time T for the secondary gas supply path 13B corresponding to the gas appliances 30,..., 30 with a small combustion amount with reference to the table 11 corresponding to the minimum gas flow rate P0 of 0.
Is obtained by the return safety confirmation time calculation means 14,
The secondary gas system (1) connected to the secondary gas supply passage 13B
3B, 30,..., 30), the pipe volume determined based on the pipe length, the pipe diameter, etc., and the secondary gas systems (13B,
, 30), a gas appliance 3 with a small amount of combustion
30, the estimated pipe capacity k corresponding to the lowest gas flow rate P0 of the combustion equipment 30,..., 30 and the table 11 can be referred to. As a result, for each secondary gas supply path 13B, The optimal return safety confirmation time T corresponding to the gas supply flow rate Q caused by the minute leakage and the minimum gas flow rate P0 of the combustion devices 30,..., 30 or the gas devices 30,. The return safety confirmation time calculation means 14 can individually obtain the time. That is, such gas appliances 30,.
0 or a secondary gas system (13) based on the return safety confirmation time T optimized by the return safety confirmation time calculation means 14 in accordance with the gas supply flow rate Q resulting from the minute leakage.
B, 30,..., 30) can be optimized, and as a result, the return safety confirmation time T can be optimized.

According to a twelfth aspect of the present invention for solving the above-mentioned problem, in the gas security apparatus 10 according to the tenth aspect, the return safety confirmation time calculating means 14 comprises the first means. By applying the estimated pipe capacity k obtained by the pipe capacity estimating means 12 to the correlation obtained in advance, the return safety confirmation time T corresponding to the pressure relaxation time ΔT obtained by the pipe capacity estimating means 12 is obtained. The hardware configuration is configured as follows.

According to the twelfth aspect, the same effect as the tenth aspect can be obtained.

According to a thirteenth aspect of the present invention for solving the above-mentioned problems, the amount of gas used is measured.
Detects an abnormal supply of the gas supplied to the secondary gas system (13B, 30,..., 30) and shuts off the gas supply, and supplies the gas to the secondary gas system (13B, 30,..., 30). An electronic gas meter 2 using the gas security device 10 according to any one of claims 10 to 12, wherein the supply of gas is restored by detecting that the supply abnormality of the supplied gas has been released.
0, the gas security device 10 and gas appliances 30,...
A combustion control means 22 for activating the combustion operation by activating 30;
The gas supply flow rate Q during the combustion of the gas appliances 30,..., 30 with a small combustion amount is determined as the reference gas supply flow rate Q0, and the gas pressure P of the secondary gas supply passage 13B at that time is determined as the reference gas pressure P0. Pressure measurement sensor 24 and gas shutoff valve 2 provided in gas supply passage 13
6, and a gas shutoff valve 26 for temporarily shutting off the supply of gas in the gas supply passage 13.

According to the thirteenth aspect of the present invention, in addition to the effect of any one of the tenth to twelfth aspects, any gas pressure measuring sensor such as a membrane type flow sensor or an ultrasonic type flow sensor is provided. 24, the gas supply flow rate Q flowing through the secondary gas supply passage 13B detected by the gas pressure measurement sensor 24 when the pressure relaxation time ΔT is measured and the pressure relaxation time calculated by the pipe capacity estimating means 12. Δ
T is calculated by the pipe capacity estimating means 12 to obtain the estimated pipe capacity k. Therefore, the estimated pipe capacity k corresponding to the gas supply flow rate Q resulting from the minute leakage and the minimum gas flow rate P0 of the combustion equipment 30,. , A pipe volume determined based on a pipe length, a pipe diameter, and the like for each of the secondary gas systems (13B, 30,..., 30) connected to the secondary gas supply path 13B, , 30 constituting the system (13B, 30,..., 30) can be determined in accordance with the amount of combustion of the gas appliances 30,. Pressure relaxation time Δ obtained by means 12
T and the gas supply flow rate Q flowing through the secondary gas supply passage 13B detected by the gas pressure measurement sensor 24 at that time are calculated by the pipe capacity estimating means 12 to obtain the minimum gas flow rate P0 of the combustion equipment 30,. The corresponding estimated pipe capacity k is determined, and the estimated pipe capacity k and the minimum gas flow rate P of the combustion equipment 30,.
With reference to the table 11 corresponding to 0, the return safety confirmation time calculation means 14 determines the optimal return safety confirmation time T for the secondary gas supply path 13B corresponding to the gas appliances 30,. I'm asking. Secondary gas system (13B, 30,..., 30) connected to secondary gas supply passage 13B
The pipe volume determined based on the pipe length, the pipe diameter, etc. of each of the pipes, and the gas appliances 30,..., 30 of each of the secondary gas systems (13B, 30,. 30, the estimated pipe capacity k corresponding to the minimum gas flow rate P0 of the combustion equipment 30, and the table 11 can be referred to. As a result, the gas supply flow rate attributable to the minute leakage for each of the secondary gas supply paths 13B Q and combustion equipment 30, ..., 30
, 30 corresponding to the minimum gas flow rate P0 or the gas appliances 30,..., 30 with a small amount of combustion can be individually determined by the return safety confirmation time calculating means 14. . That is, the gas supply flow rate Q flowing through the secondary gas supply path 13B detected by the gas pressure measurement sensor 24 is monitored for an optimum time based on the return safety confirmation time T, and the evaluation of whether or not the gas supply abnormality has been eliminated is performed. It is possible to optimize the determination accuracy.

According to a fourteenth aspect of the present invention, which is achieved by the present invention to solve the above problem, in the electronic gas meter 20 according to the thirteenth aspect, the secondary gas supply passage 13 is provided.
A hardware configuration having a security control unit 27 that monitors the gas supply flow rate Q flowing through B for the return safety confirmation time T and evaluates whether or not the gas supply abnormality has been eliminated is adopted.

According to the fourteenth aspect of the present invention, in addition to the effect of the thirteenth aspect, any one of the gas pressure measuring sensors 24 such as a membrane type flow sensor or an ultrasonic type flow sensor can be used.
Is used, the security control means 27 monitors the gas supply flow rate Q flowing through the secondary gas supply passage 13B detected by the gas pressure measurement sensor 24 for an optimal time based on the return safety confirmation time T, and This makes it possible to optimize the accuracy of the determination of whether or not the supply abnormality has been eliminated.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of a gas security device according to the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram for explaining an embodiment of a gas security device 10 for executing a gas shutoff / return method according to the present invention. FIG. 3 is a graph for explaining how the gas pressure P in the gas pipe decreases immediately after the shut-off valve returns. FIG. 4 is a graph for explaining a state of measurement of the pressure relaxation time ΔT which is executed by using the gas pressure drop in the gas pipe immediately after the test interruption. FIG. 5 shows an estimated pipe capacity k calculated using the pressure relaxation time ΔT measured in FIG. 4 and the gas supply flow rate Q at that time.
9 is a graph for explaining the relationship between (= ΔT / Q) and a preset return safety confirmation time T.

The gas security device 10 shown in FIG.
Detects an abnormal supply of the gas supplied to the secondary gas system (13B, 30, ..., 30) and shuts off the gas supply, and supplies the gas to the secondary gas system (13B, 30, ..., 30). In addition to the function of recovering the supply of the gas by detecting that the supply abnormality of the supplied gas has been released, the secondary gas is detected by detecting an abnormality such as a minute gas leak in the LP gas flowing through the secondary gas supply passage 13B. After the return of the gas supply after the LP gas supply to the gas supply path 13B is cut off (specifically, after the valve return shown in FIG. 3 is performed), the pipe pressure P (specifically, FIG. The return safety confirmation time T, which is a monitoring period for evaluating whether or not the supply abnormality caused by the slight leakage of the LP gas or forgetting to close the gas stopper, is observed by observing the graphs g1, g2, and g3) shown in FIG. When the gas flow rate is calculated, the gas flow rate on the downstream side (gas user side) Pipe shape (cross-sectional area and tube length) estimated pipe capacity is calculated by the estimated value of the pipe volume of secondary gas supply passage 13B on the basis of k the following side gas supply passage 13B (= delta
T / Q) and a function of previously obtaining a correlation graph (specifically, a graph g6 shown in FIG. 5) between the return safety confirmation time T and a measured value of the measured estimated pipe capacity k (= ΔT / Q). Is applied to a correlation graph (specifically, a graph g6 shown in FIG. 5) to obtain a return safety confirmation time T according to an actually measured value of the estimated pipe capacity k (= ΔT / Q).

In order to realize such functions, the gas security apparatus 10 has a hardware configuration including a table 11, a pipe capacity estimating means 12, and a return safety confirmation time calculating means 14.

Table (graph g6 shown in FIG. 5) 11
Is an estimated value of the pipe capacity of the secondary gas supply path 13B based on the pipe shape (cross-sectional area and pipe length) of the secondary gas supply path 13B downstream of the gas shutoff valve 26 (gas user side). The supply of the gas in the secondary gas supply path 13B is returned to the estimated pipe capacity k (= ΔT / Q) calculated by the calculation, and the pipe pressure P flowing through the secondary gas supply path 13B (specifically, , G4 and g5) shown in FIG.
FIG. 5 is a correlation graph of a return safety confirmation time T which is a monitoring period for evaluating whether or not a supply abnormality caused by a minute leakage of gas or forgetting to close a gas stopper has been eliminated. Has a function of holding the graph g6) in advance. Specifically, the nonvolatile semiconductor memory device (EEPRO)
M) etc. are used.

The pipe capacity estimating means 12 shown in FIG. 1 operates the gas shutoff valve 26 provided in the gas supply path 13 to temporarily cut off the supply of gas in the gas supply path 13 (specifically, The gas pressure P in the secondary gas supply path 13B during the test interruption execution period shown in FIG. 4 is reduced by the pressure difference P0-P1 (FIG. 4) of the preset gas pressure P constant ΔP. Pressure relaxation time ΔT, which is the required time t
And a function of dividing the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time (pressure relaxation time ΔT / gas supply flow rate Q) to obtain an estimated pipe capacity k (= ΔT / Q). Specifically, it is realized by a microprocessor.

Here, the pipe capacity estimating means 12 divides the gas supply flow rate Q flowing through the secondary gas supply passage 13B at the time of measuring the pressure relaxation time ΔT (pressure relaxation time ΔT / gas supply flow rate Q) to estimate the pipe. The capacity k (= ΔT / Q) can be obtained.

By providing such a pipe capacity estimating means 12, the gas shutoff provided in the gas supply passage 13 can be performed regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used. By operating the valve 26 to temporarily cut off the supply of gas in the gas supply path 13, the gas equipment 30,. Then, the gas pressure P of the secondary gas supply passage 13B at that time can be obtained as the reference gas pressure P0. The reference gas pressure P0 obtained in this manner is used as a criterion for determining a gas pressure drop caused by the gas supply flow rate Q at the time of a small leak, and a descent time until the gas pressure P decreases from the reference gas pressure P0 by a predetermined pressure. Is determined by the pipe capacity estimating means 12 as the pressure relaxation time ΔT, and the gas supply flow rate Q flowing through the secondary gas supply passage 13B and the pressure relaxation time Δ are measured when the pressure relaxation time ΔT determined by the pipe capacity estimating means 12 is measured.
T is divided by the pipe capacity estimating means 12 (pressure relaxation time ΔT /
Since the estimated pipe capacity k (= ΔT / Q) is obtained by using the gas supply flow rate Q), the estimated pipe capacity corresponding to the gas supply flow rate Q caused by the minute leakage and the minimum gas flow rate P0 of the combustion equipment 30,. The capacity k (= ΔT / Q) is changed to the secondary gas supply path 1
The secondary gas system (13B, 30, ..., 3B) connected to 3B
30) A pipe volume determined based on a pipe length, a pipe diameter, etc. for each secondary gas system (13B, 30,..., 30)
Can be determined in accordance with the amount of combustion of the gas appliances 30,..., 30 such as a water heater. Further, the pressure relaxation time ΔT determined for use in the ignition of gas appliances 30,..., 30 such as water heaters with a small combustion amount, and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time. The pipe capacity estimating means 12 divides (pressure relaxation time ΔT / gas supply flow rate Q) to obtain an estimated pipe capacity k (= ΔT / Q) corresponding to the minimum gas flow rate P0 of the combustion devices 30,. The gas appliance 30 such as a water heater with a small combustion amount is referred to with reference to a table (graph g6 shown in FIG. 5) 11 corresponding to the capacity k (= ΔT / Q) and the minimum gas flow rate P0 of the combustion appliances 30,. ,..., The optimal return safety confirmation time T (Tmin
≤ T ≤ Tmax (see FIG. 5) by the return safety confirmation time calculation means 14, so that each secondary gas system (13B, 30,..., 30) connected to the secondary gas supply path 13B The pipe volume determined based on the pipe length, the pipe diameter, and the like, and the gas equipment 30,..., 30 such as a water heater with a small combustion amount constituting each secondary gas system (13B, 30,. It is possible to refer to the estimated pipe capacity k (= ΔT / Q) and the table (graph g6 shown in FIG. 5) 11 corresponding to the minimum gas flow rate P0 of the combustion devices 30,... As a result, the gas supply flow rate Q resulting from the minute leakage and the combustion equipment 30,.
The optimal return safety confirmation time T (Tmin ≦ T ≦ Tm) corresponding to the minimum gas flow rate P0 of 30 or the use of the gas appliances 30,...
ax, see FIG. 5) can be individually obtained by the return safety confirmation time calculation means 14. That is, the return safety confirmation time optimized by the return safety confirmation time calculating means 14 in correspondence with the gas equipment 30,..., 30 such as a water heater or the like having a small combustion amount, or the gas supply flow rate Q caused by the minute leakage. T based on the secondary gas system (13B, 3
0,..., 30) can be optimized, and as a result, the return safety confirmation time T
Can be customized to the optimal value.

The return safety confirmation time calculation means 14 applies the estimated pipe capacity k (= ΔT / Q) to the table (graph g6 shown in FIG. 5) 11 to confirm the optimal return safety for the secondary gas supply passage 13B. It has a function of obtaining a time T (Tmin ≦ T ≦ Tmax, see FIG. 5), and is specifically realized by the aforementioned microprocessor.

Here, the return safety confirmation time calculating means 14
The estimated pipe capacity k (= ΔT / Q) obtained by the pipe capacity estimating means 12 is applied to the correlation graph (specifically, the graph g6 shown in FIG. 5) obtained in advance by the first means. Has a function of obtaining a return safety confirmation time T corresponding to the pressure relaxation time ΔT obtained in the above.

According to the gas security apparatus 10 having such a hardware configuration, the pipe volume estimating means 12 can be used regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used. The obtained pressure relaxation time ΔT and the secondary gas supply path 13B at that time
Divided by the gas supply flow rate Q flowing to the pressure (pressure relaxation time ΔT /
The gas supply flow rate Q) and the estimated pipe capacity k (= ΔT / Q) can be obtained by using the pipe capacity estimation means 12, and the estimated pipe capacity k (= ΔT / Q) and the table (FIG. 5) Referring to the graph g6) shown in FIG. 11, the optimum return safety confirmation time T (Tmin ≦ T ≦) for the secondary gas supply passage 13B.
Tmax (see FIG. 5) can be obtained by using the return safety confirmation time calculation means 14, so that the secondary gas system (13B, 3B) connected to the secondary gas supply passage 13B can be obtained.
0,..., 30), the pipe volume determined based on the pipe length, the pipe diameter, and the like, and the secondary gas systems (13B, 30,
, 30) and gas appliances 30, ..., 3 such as water heaters
It is possible to refer to the estimated pipe capacity k (= ΔT / Q) and the table (graph g6 shown in FIG. 5) 11 corresponding to the combustion amount of 0 (specifically, g4 and g5 shown in FIG. 4), As a result, the optimum return safety confirmation time T (Tmin ≦ T ≦ Tmax, see FIG. 5) can be individually obtained for each secondary gas supply path 13B. That is, it is possible to optimize the determination accuracy of the return determination of the secondary gas system (13B, 30,..., 30) based on the optimized return safety confirmation time T. As a result, the return safety confirmation time T can be customized to an optimum value.

Next, an embodiment of the electronic gas meter of the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram for explaining an embodiment of an electronic gas meter 20 for executing the gas shut-off return method according to the present invention.

The electronic gas meter 20 shown in FIG. 1 is provided in a general house, an apartment house, a store, or the like of a user who uses LP gas, measures an amount of gas used, and measures a secondary gas system (13).
B, 30,..., 30), the supply of gas is interrupted by detecting a supply abnormality of the gas supplied to the secondary gas system (13).
B, 30,..., 30) perform a function of recovering the gas supply by detecting that the supply abnormality of the gas supplied to the gas security device 10, the combustion control means 22, and the gas pressure A hardware configuration including the measurement sensor 24, the gas shutoff valve 26, and the security control means 27 was adopted.

[0057] The combustion control means 22 is connected to the gas supply path 13 and is provided with gas appliances 30,.
It has a function of activating “0” to promote the combustion operation, and is specifically realized by using the aforementioned microprocessor.

The gas pressure measuring sensor 24 determines the gas supply flow rate Q during combustion of the gas appliances 30,..., 30 such as water heaters with a small combustion amount as the reference gas supply flow rate Q0, It has a function to determine the gas pressure P of the gas supply path 13B as the reference gas pressure P0, and is specifically realized by using a membrane type flow sensor or an ultrasonic type flow sensor.

Specifically, when a membrane type flow sensor is used, one flow pulse (0.7 liter / pulse) is generated for a gas supply flow rate Q of 0.7 liter, and
A gas supply flow rate Q of less than liter / hour is detected. That is, in this case, a flow rate pulse is generated from the membrane type flow sensor at a pulse rate of 1 pulse / minute (1 pulse in 21 / 0.7 = 30 seconds), and a gas supply flow rate Q of less than 21 liter / hour is generated. Is 1 minute return safety confirmation time T
No flow pulses will be intermittent.

On the other hand, when the above-mentioned ultrasonic flow sensor is used, a gas flow measuring method using the propagation speed of ultrasonic waves is used instead of a mechanical detection method such as a membrane flow sensor, so that the gas supply flow rate Q The measurement sampling time interval is about several seconds (specifically, 2 seconds), and the gas supply flow rate Q can be measured instantaneously as compared with the membrane type flow sensor. It can be shortened to about several seconds compared to a sensor.

The gas cutoff valve 26 has a function of operating the gas cutoff valve 26 provided in the gas supply passage 13 to temporarily cut off the gas supply in the gas supply passage 13.

The security control means 27 monitors the gas supply flow rate Q (specifically, g1, g2, g3 shown in FIG. 3) flowing through the secondary gas supply path 13B for the return safety confirmation time T, and monitors the LP gas. Has the function of evaluating whether or not the supply abnormality caused by the minute gas leak or forgetting to close the gas stopper has been specifically realized by using a membrane type flow sensor or an ultrasonic type flow sensor. ing.

According to the security control means 27, the gas pressure measurement sensor 24 detects whether the gas pressure measurement sensor 24 uses any of the gas pressure measurement sensors 24, such as a membrane flow sensor or an ultrasonic flow sensor. The security control means 27 monitors the gas supply flow rate Q flowing to the secondary gas supply path 13B for an optimum time based on the return safety confirmation time T, and a supply abnormality caused by a slight leak of the LP gas or forgetting to close the gas stopper is detected. This makes it possible to optimize the accuracy of the determination of whether or not the determination has been made.

As described above, the electronic gas meter 20
According to the method, the secondary gas detected by the gas pressure measurement sensor 24 when the pressure relaxation time ΔT is measured, regardless of whether the gas pressure measurement sensor 24 such as the membrane flow sensor or the ultrasonic flow sensor is used. The gas supply flow rate Q flowing through the supply passage 13B and the pressure relaxation time ΔT obtained by the pipe capacity estimation means 12 are divided by the pipe capacity estimation means 12 (pressure relaxation time ΔT / gas supply flow rate Q), and the estimated pipe capacity k (=
ΔT / Q), the gas supply flow rate Q resulting from the minute leakage and the minimum gas flow rate P of the combustion equipment 30,.
The estimated pipe capacity k (= ΔT / Q) corresponding to the secondary gas system (13) connected to the secondary gas supply passage 13B.
B, 30,..., 30), the pipe volume determined based on the pipe length, the pipe diameter, etc., and the secondary gas systems (13B, 3B).
0,..., 30)
, 30 and the pressure relaxation time ΔT determined by the pipe capacity estimating means 12 in correspondence with the use of the gas appliances 30, such as water heaters, with a small combustion amount. And the gas supply flow rate Q flowing through the secondary gas supply passage 13B detected by the gas pressure measurement sensor 24 at that time.
Is divided by the pipe capacity estimating means 12 (pressure relaxation time ΔT /
The gas supply flow rate Q) is used to obtain an estimated pipe capacity k (= ΔT / Q) corresponding to the lowest gas flow rate P0 of the combustion equipment 30,..., 30, and the estimated pipe capacity k (= ΔT / Q) and the combustion equipment 3
With reference to the table (graph g6 shown in FIG. 5) 11 corresponding to the minimum gas flow rate P0 of 0,..., 30 and corresponding to the use of the ignition of gas appliances 30,. The return safety confirmation time calculation means 14 finds the optimal return safety confirmation time T (Tmin ≦ T ≦ Tmax, see FIG. 5) for the secondary gas supply passage 13B. Secondary gas supply path 13
B, the secondary gas system (13B, 30,..., 3)
0) a gas volume 30, such as a hot water heater or the like, which constitutes each secondary-side gas system (13B, 30, ..., 30) and has a small combustion amount, …,
Combustion equipment 30, ..., 30 corresponding to the use of 30 sparks
Estimated pipe capacity k (= ΔT) corresponding to the minimum gas flow rate P0
/ Q) and the table (graph g6 shown in FIG. 5) 11 can be referred to, and as a result, the secondary gas supply path 13
Gas supply flow rate Q due to micro leak and combustion equipment 3 for each B
The optimum return safety confirmation time T (Tmin) corresponding to the minimum gas flow rate P0 of 0,..., 30 or used for the ignition of the gas appliances 30,.
≦ T ≦ Tmax (see FIG. 5) by the return safety confirmation time calculation means 14 individually. That is, the gas supply flow rate Q flowing through the secondary gas supply path 13B detected by the gas pressure measurement sensor 24 is monitored for an optimum time based on the return safety confirmation time T, and a slight leak of the LP gas or forgetting to close the gas stopper is performed. This makes it possible to optimize the accuracy of the determination of whether or not the supply abnormality caused by the error has been eliminated.

Next, an embodiment of the gas shut-off return method of the present invention will be described with reference to the drawings.

FIG. 2 is a flow chart for explaining one embodiment of the gas shut-off return method executed by the electronic gas meter 20 of FIG.

The gas shut-off reset method shown in FIG. 2 detects an abnormal supply of gas supplied to the secondary gas system (13B, 30,..., 30) and shuts off the gas supply (step S).
3), and the secondary gas system (13B, 30, ..., 30)
Has the step of detecting that the supply abnormality of the gas supplied to the gas has been released and restoring the supply of the gas, and specifically, is configured around the first step to the seventh step described below. ,
It is described by a program code executable by the aforementioned microprocessor.

In the first step, an abnormality such as a minute gas leak is detected in the LP gas flowing through the secondary gas supply passage 13B (learning starts), and the supply of the LP gas to the secondary gas supply passage 13B is shut off. After the return of the gas supply later (step S3) (specifically, after executing the valve return shown in FIG. 3), is the supply abnormality caused by a minute leak of the LP gas or forgetting to close the gas stopper eliminated? When the return safety confirmation time T, which is a monitoring period for evaluating whether or not to perform the evaluation (Step S7), is determined (Step S10), the secondary gas supply passage 13B downstream (gas user side) of the gas shutoff valve 26. Estimated piping capacity k (= Δ
T / Q) (step S9) and the return safety confirmation time T are determined in advance (specifically, the graph g6 shown in FIG. 5), and the measured estimated pipe capacity k (= ΔT / Q) is calculated. The measured values (steps S8 and S9) are referred to a correlation graph (specifically, a graph g6 shown in FIG. 5) (step S1).
0), the return safety confirmation time T according to the actually measured value of the estimated pipe capacity k (= ΔT / Q) can be obtained (step S11), and the two values on the downstream side (gas user side) of the gas shutoff valve 26 can be obtained.
Estimated pipe capacity k (= ΔT / Q) calculated by estimating the pipe capacity of the secondary gas supply path 13B based on the pipe shape (cross-sectional area and pipe length) of the secondary gas supply path 13B (step S)
9), the supply of the gas in the secondary gas supply passage 13B was returned, and the pressure P (specifically, g4 and g5 shown in FIG. 4) in the pipe flowing in the secondary gas supply passage 13B was monitored. At this time (steps S3 to S7), a return safety confirmation time, which is a monitoring period for evaluating whether or not a supply abnormality caused by a minute leakage of LP gas or forgetting to close the gas stopper (step S7). In this step, a correlation graph of T (specifically, a graph g6 shown in FIG. 5) is obtained in advance.

The second step is a step of operating the gas appliances 30,..., 30 such as a water heater with a small combustion amount connected to the gas supply path 13 (step S1) to promote the combustion operation.

According to the second step, regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used, a gas such as a water heater with a small combustion amount connected to the gas supply passage 13 is used. Since the pressure relaxation time ΔT is determined in a state where the devices 30,..., 30 are operated, the gas supply flow rate Q caused by the minute leakage and the minimum gas supply flow rate Q of the combustion devices 30,. 2 connected to the gas supply path 13B
, 30 for each of the secondary gas systems (13B, 30,..., 30), and the hot water supply constituting each of the secondary gas systems (13B, 30,..., 30). , 30, the gas appliances 30,... Further, the pressure relaxation time ΔT determined for use in the ignition of the gas appliances 30,..., 30 such as water heaters with a small amount of combustion, and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time. Estimated pipe capacity k (= ΔT / Q) corresponding to use for ignition of gas appliances 30,. , And a correlation graph (specifically, a graph shown in FIG. 5) corresponding to use for the ignition of gas appliances 30,... g6) (step S10), the gas appliance 3 such as a water heater with a small combustion amount.
Optimal return safety confirmation time T (Tmin ≦ T ≦ Tm) for the secondary gas supply passage 13B corresponding to the use of 0,.
ax, see FIG. 5).
The secondary gas system (13B, 30, ..., 3B) connected to 3B
30) A pipe volume determined based on a pipe length, a pipe diameter, etc. for each secondary gas system (13B, 30,..., 30)
Gas equipment 30, such as a water heater with a small amount of combustion,
…, Estimated pipe capacity k (=
ΔT / Q) and the correlation graph (specifically, the graph g6 shown in FIG. 5) can be referred to, and as a result, the gas appliance 30 such as a water heater with a small combustion amount can be provided for each secondary gas supply passage 13B. ,..., 30 can be individually obtained for the optimum return safety confirmation time T (Tmin ≦ T ≦ Tmax, see FIG. 5). That is, the secondary gas system (13B, 30,...) Is based on the return safety confirmation time T optimized for use in the ignition of the gas appliances 30,... …, 3
It is possible to optimize the determination accuracy of the return determination of 0), and as a result, it is possible to customize the return safety confirmation time T to an optimal value.

In the third step, the gas supply flow rate Q at the time of combustion (step S1) of the gas appliances 30,..., 30 such as water heaters with a small combustion amount is determined as the reference gas supply flow rate Q0 (step S2). In this step, the gas pressure P in the secondary gas supply passage 13B at that time is determined as a reference gas pressure P0 (step S5).

According to the third step, regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used, the gas supplied from the gas supply path 13 and connected to the gas supply path 13 such as a water heater with a small amount of combustion is used. When the devices 30,..., 30 are operated, the gas pressure P of the secondary gas supply path 13B at that time is determined as a reference gas pressure P0, and this reference gas pressure P0 is caused by the gas supply flow rate Q at the time of micro leakage. Is used as a criterion for determining a decrease in gas pressure.
T, the gas supply flow rate Q resulting from the minute leakage and the minimum gas flow rate P0 of the combustion devices 30,.
, A pipe volume determined based on a pipe length and a pipe diameter of each of the secondary gas systems (13B, 30,..., 30) connected to the secondary gas supply path 13B, Line (1
3B, 30,..., 30) can be determined in accordance with the amount of combustion of the gas appliances 30,. Furthermore, gas appliances 30, such as a water heater with a small amount of combustion,
.., 30 and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time (pressure relaxation time ΔT / gas supply flow rate Q, step S9). ) To determine the estimated pipe capacity k (= ΔT / Q) corresponding to the use of the gas appliances 30,...
/ Q) and gas appliances 30, such as water heaters with a small amount of combustion,
.., 30 (refer to the graph g6 shown in FIG. 5) (step S1).
0), gas appliances 30,..., 3
Since the optimum return safety confirmation time T (Tmin ≦ T ≦ Tmax, see FIG. 5) for the secondary gas supply path 13B corresponding to the use of the ignition of 0 is determined, the secondary gas supply path 13B is connected to the secondary gas supply path 13B. The pipe volume determined based on the pipe length, the pipe diameter, etc. of each of the secondary gas systems (13B, 30,..., 30) and the secondary gas systems (13B, 30,. An estimated pipe capacity k (= ΔT / Q) and a correlation graph (specifically, graph g6 shown in FIG. 5) corresponding to the use of the gas appliances 30,... ) Can be referred to, and as a result, the secondary gas supply path 1
For each 3B, the gas supply flow rate Q caused by the minute leakage and the minimum gas flow rate P0 of the combustion equipment 30,..., 30 are used or used for the ignition of the gas equipment 30,. Optimal return safety confirmation time T (Tmi
n ≦ T ≦ Tmax, see FIG. 5). That is, the secondary side gas is determined based on the return safety confirmation time T optimized in accordance with the gas equipment 30,..., 30 such as a water heater with a small combustion amount, or the gas supply flow rate Q caused by a minute leak. The system (13B, 30,
, 30) can be optimized, and as a result, the return safety confirmation time T can be customized to an optimal value.

In the fourth step, the gas shutoff valve 26 provided in the gas supply path 13 is operated (step S3), and the supply of gas in the gas supply path 13 is temporarily cut off (step S3).
Steps 3 and 4).

According to the fourth step, the gas shut-off valve 2 provided in the gas supply passage 13 is used regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used.
6 (Step S3) and temporarily cut off the supply of gas in the gas supply path 13 (Steps S3 and S4), thereby connecting to the gas supply path 13 and supplying gas equipment such as a water heater with a small combustion amount. In a state where 30, 30, ..., 30 are operated, the gas pressure P of the secondary gas supply passage 13B at that time can be obtained as the reference gas pressure P0 (step S5). The reference gas pressure P0 obtained in this manner is used as a criterion for determining a gas pressure drop caused by the gas supply flow rate Q at the time of a small leak, and a descent time until the gas pressure P decreases from the reference gas pressure P0 by a predetermined pressure. Is determined as the pressure relaxation time ΔT, the gas supply flow rate Q resulting from the minute leakage and the minimum gas flow rate P0 of the combustion devices 30,..., 30 are calculated by using the secondary gas supply path 13B connected to the secondary gas supply path 13B. A pipe volume determined based on a pipe length, a pipe diameter, and the like for each system (13B, 30,..., 30) and a water heater that constitutes each secondary-side gas system (13B, 30,..., 30). .., 30 can be determined in accordance with the amount of combustion. Furthermore, gas appliances 3 such as water heaters with a small amount of combustion
The pressure relaxation time ΔT determined for use in the ignition of 0,..., 30 and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time are divided (pressure relaxation time ΔT / gas supply flow rate Q, In step S9), an estimated pipe capacity k (= ΔT / Q) corresponding to the use of the gas appliances 30,...
ΔT / Q) and gas appliances 3 such as water heaters with low combustion volume
Reference is made to a correlation graph (specifically, a graph g6 shown in FIG. 5) corresponding to the use of sparks of 0,..., 30 (Step S10), and the gas appliances 30,
…, Secondary gas supply path 1 corresponding to use in 30 sparks
3B optimal return safety confirmation time T (Tmin ≦ T ≦ Tmax,
5 (see FIG. 5), the secondary gas supply path 13B
The secondary gas system (13B, 30, ..., 3) connected to
0) a gas volume 30, such as a hot water heater or the like, which constitutes each secondary-side gas system (13B, 30, ..., 30) and has a small combustion amount, …,
Estimated pipe capacity k (= ΔT) corresponding to use for 30 sparks
/ Q) and a correlation graph (specifically, a graph g6 shown in FIG. 5) can be referred to, and as a result, the gas supply flow rate Q caused by the minute leakage and the combustion equipment for each secondary gas supply path 13B Gas appliances 30,..., Such as water heaters corresponding to the minimum gas flow rate P0 of 30, 30,.
The optimum return safety confirmation time T (Tmin ≦ T ≦ Tmax, see FIG. 5) corresponding to the use of the 30 sparks can be individually obtained. That is, the secondary side gas is determined based on the return safety confirmation time T optimized in accordance with the gas equipment 30,..., 30 such as a water heater with a small combustion amount, or the gas supply flow rate Q caused by a minute leak. System (13B,
(30,..., 30) can be optimized, and as a result, the return safety confirmation time T can be customized to an optimum value.

The fifth step is to divide the gas supply flow rate Q flowing through the secondary gas supply passage 13B when measuring the pressure relaxation time ΔT (pressure relaxation time ΔT / gas supply flow rate Q, step S
9) Then, the estimated pipe capacity k (= ΔT /
Q) (steps S3 to S9).

In the sixth step, the gas shutoff valve 26 provided in the gas supply passage 13 is operated (step S3), and the supply of gas in the gas supply passage 13 is temporarily shut off (specifically, while the gas supply is stopped). Means that the gas pressure P in the secondary gas supply passage 13B during the test interruption execution period shown in FIG. 4 decreases by a pressure difference P0-P1 (FIG. 4, step S6) of a preset gas pressure P constant ΔP. The pressure relaxation time ΔT which is the time t required (step S8) and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time are divided (pressure relaxation time ΔT / gas supply flow rate Q, step S9). (Steps S3 to S9) to obtain an estimated pipe capacity k (= ΔT / Q), and an estimated pipe capacity k (= ΔT / Q) and a correlation graph (specifically, a graph g6 shown in FIG. 5). (Step S10) Secondary gas This is a step of obtaining an optimal return safety confirmation time T (Tmin ≦ T ≦ Tmax, see FIG. 5) for the supply path 13B (step S11).

According to the fifth step or the sixth step, the gas shut-off valve 26 provided in the gas supply passage 13 is used regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used. Is activated (step S3), and the supply of gas in the gas supply path 13 is temporarily cut off (steps S3, S4), thereby connecting the gas equipment 30 such as a water heater connected to the gas supply path 13 and having a small combustion amount. ,.., 30 are operated, the gas pressure P of the secondary gas supply passage 13B at that time is obtained as a reference gas pressure P0 (step S5).
5) Be able to do it. The reference gas pressure P0 obtained in this manner is used as a criterion for determining the gas pressure drop caused by the gas supply flow rate Q at the time of a small leak, and the descent time until the gas pressure P decreases from the reference gas pressure P0 by a predetermined pressure. Is obtained as the pressure relaxation time ΔT, and the gas supply flow rate Q flowing through the secondary gas supply passage 13B and the pressure relaxation time ΔT during the measurement of the pressure relaxation time ΔT are divided (pressure relaxation time ΔT / gas supply flow rate Q, step S9). ) To obtain the estimated pipe capacity k (= ΔT / Q). Therefore, the estimated pipe capacity k (= ΔT / Q) corresponding to the gas supply flow rate Q resulting from the minute leakage and the minimum gas flow rate P0 of the combustion equipment 30,. ΔT / Q)
, A pipe volume determined based on a pipe length and a pipe diameter of each of the secondary gas systems (13B, 30,..., 30) connected to the secondary gas supply path 13B, Line (1
3B, 30,..., 30) can be determined in accordance with the amount of combustion of the gas appliances 30,. Furthermore, gas appliances 30, such as a water heater with a small amount of combustion,
.., 30 and the gas supply flow rate Q flowing through the secondary gas supply passage 13B at that time (pressure relaxation time ΔT / gas supply flow rate Q, step S9). ), And the estimated pipe capacity k (= ΔT / Q) corresponding to the minimum gas flow rate P0 of the combustion equipment 30,.
And the estimated pipe capacity k (= ΔT / Q) and the combustion equipment 3
Reference is made to a correlation graph (specifically, graph g6 shown in FIG. 5) corresponding to the lowest gas flow rate P0 of 0,.
Optimal return safety confirmation time T (Tmin ≦ T ≦ Tm) for the secondary gas supply passage 13B corresponding to the use of 0,.
ax, see FIG. 5).
The secondary gas system (13B, 30, ..., 3B) connected to 3B
30) A pipe volume determined based on a pipe length, a pipe diameter, etc. for each secondary gas system (13B, 30,..., 30)
Gas equipment 30, such as a water heater with a small amount of combustion,
…, 30 combustion devices corresponding to the use of sparks 30,
Estimated piping capacity k (=
ΔT / Q) and the correlation graph (specifically, the graph g6 shown in FIG. 5) can be referred to, and as a result, the gas supply flow rate Q and the combustion The gas appliances 30, such as water heaters, which correspond to the minimum gas flow rate P0 of the appliances 30,.
,.., 30 (Tmin ≦ T ≦ Tmax, see FIG. 5) can be individually obtained. That is, the secondary side gas is determined based on the return safety confirmation time T optimized in accordance with the gas equipment 30,..., 30 such as a water heater with a small combustion amount, or the gas supply flow rate Q caused by a minute leak. Line (13
(B, 30,..., 30) can be optimized, and as a result, the return safety confirmation time T can be customized to an optimal value.

In the seventh step, the pipe pressure P (specifically, g1, g2, g3 shown in FIG. 3) based on the gas supply flow rate Q flowing through the secondary gas supply passage 13B is returned to the return safety confirmation time T
Is monitored to evaluate whether or not the supply abnormality caused by the slight leakage of the LP gas or forgetting to close the gas stopper has been eliminated (step S7). This is the step of executing step S8 when the vehicle has just descended (Y in step S7).

According to the seventh step, the flow to the secondary gas supply passage 13B is measured when the pressure relaxation time ΔT is measured, regardless of whether the membrane type flow sensor or the ultrasonic type flow sensor is used. Gas supply flow rate Q and pressure relaxation time ΔT
(Pressure relaxation time ΔT / gas supply flow rate Q, step S9) to obtain the estimated pipe capacity k (= ΔT / Q), so that the gas supply flow rate Q due to the minute leakage and the combustion equipment 3
The estimated pipe capacity k (= ΔT / Q) corresponding to the minimum gas flow rate P0 of 0,..., 30 is set to the secondary gas system (13B, 30,..., 30) connected to the secondary gas supply passage 13B. The pipe volume determined based on the pipe length, the pipe diameter, and the like for each pipe, and the amount of combustion of gas appliances 30,..., 30 such as water heaters constituting each of the secondary gas systems (13B, 30,..., 30) The pressure relaxation time ΔT determined for use in the ignition of the gas appliances 30,..., 30 such as water heaters with a small amount of combustion, and the pressure relaxation time ΔT Divide the flowing gas supply flow rate Q (pressure relaxation time ΔT / gas supply flow rate Q, step S9) to obtain the combustion equipment 30,.
Estimated pipe capacity k (= ΔT) corresponding to the minimum gas flow rate P0
/ Q) and a correlation graph (specifically, graph g6 shown in FIG. 5) corresponding to the estimated pipe capacity k (= ΔT / Q) and the minimum gas flow rate P0 of the combustion equipment 30,. (Step S10), the recovery safety confirmation time T (Tmin ≦ T) that is optimal for the secondary gas supply passage 13B corresponding to the ignition of the gas appliances 30,...
T ≦ Tmax, see FIG. 5). The secondary gas system (13B, 30,...) Connected to the secondary gas supply path 13B
, 30), the pipe volume determined based on the pipe length, the pipe diameter, etc., and the secondary gas systems (13B, 30,.
Gas equipment 3 such as a water heater with a small combustion amount constituting 0)
Combustion equipment 30,
..., estimated pipe capacity k corresponding to 30 minimum gas flow rates P0
(= ΔT / Q) and the correlation graph (specifically, graph g6 shown in FIG. 5) can be referred to.
Gas equipment 3 such as a water heater with a small amount of combustion corresponding to the gas supply flow rate Q resulting from the minute leak and the minimum gas flow rate P0 of the combustion equipment 30, ..., 30 for each of the secondary gas supply paths 13B.
The optimum return safety confirmation time T (Tmin ≦ T ≦ Tmax, see FIG. 5) corresponding to the use of 0,..., 30 sparks can be individually obtained. That is, the pressure P in the pipe based on the gas supply flow rate Q flowing through the secondary gas supply passage 13B is monitored for an optimum time based on the return safety confirmation time T, which is caused by a slight leakage of the LP gas or forgetting to close the gas stopper. This makes it possible to optimize the accuracy of the determination of whether or not the supply abnormality has been eliminated.

As described above, according to the gas shut-off return method, regardless of whether the membrane type flow sensor or the ultrasonic type flow sensor is used, the pressure relaxation time ΔT and the secondary By dividing the gas supply flow rate Q flowing through the side gas supply passage 13B (pressure relaxation time ΔT / gas supply flow rate Q, step S9), the estimated pipe capacity k (= ΔT / Q)
Is determined, and by referring to the estimated pipe capacity k (= ΔT / Q) and the correlation graph (specifically, the graph g6 shown in FIG. 5) (step S10), it is confirmed that the return safety is optimal for the secondary gas supply passage 13B. Since the time T (Tmin ≦ T ≦ Tmax, see FIG. 5) is obtained, the pipe length and the pipe for each secondary gas system (13B, 30,..., 30) connected to the secondary gas supply passage 13B. The amount of combustion determined by the pipe volume determined based on the diameter and the like, and the amount of combustion of gas equipment 30,..., 30 such as water heaters constituting each secondary gas system (13B, 30,. Estimated pipe capacity k (= ΔT /) corresponding to g4 and g5 shown in FIG.
Q) and a correlation graph (specifically, graph g shown in FIG. 5)
6), and as a result, the optimum return safety confirmation time T (Tmin ≦ T
.Ltoreq.Tmax, see FIG. 5). That is, based on the optimized return safety confirmation time T, the secondary gas system (13B, 30,
, 30) can be optimized, and as a result, the return safety confirmation time T can be customized to an optimal value.

[0081]

According to the first aspect of the present invention, regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used, the apparatus is connected to the secondary gas supply path. Refer to the pipe volume determined based on the pipe length, pipe diameter, etc. of each secondary gas system, and the estimated pipe capacity and correlation corresponding to the combustion amount of the gas equipment constituting each secondary gas system. As a result, the optimum return safety confirmation time can be individually obtained for each secondary gas supply path, and the determination of the return determination of the secondary gas system can be made based on the optimized return safety confirmation time. The accuracy can be optimized, and as a result, the return safety confirmation time can be optimized.

According to the second aspect of the present invention, regardless of whether the membrane type flow sensor or the ultrasonic type flow sensor is used, the pressure relaxation time and the two
Since the estimated pipe capacity is obtained by calculating the gas supply flow rate flowing to the secondary gas supply path and the optimum return safety confirmation time for the secondary gas supply path is obtained by referring to the estimated pipe capacity and correlation, Correspond to the pipe volume determined based on the pipe length, pipe diameter, etc. of each secondary gas system connected to the secondary gas supply path, and the amount of combustion of gas equipment constituting each secondary gas system. This makes it possible to refer to the estimated pipe capacity and the correlation, and as a result, it becomes possible to individually determine the optimum return safety confirmation time for each secondary gas supply path. That is, it is possible to optimize the determination accuracy of the return determination of the secondary gas system based on the optimized return safety confirmation time. As a result, the return safety confirmation time can be optimized. You can plan.

According to the third or fourth aspect of the present invention,
In either case of using a membrane type flow sensor or using an ultrasonic type flow sensor, since the pressure relaxation time is determined in a state where the gas equipment connected to the gas supply path and the combustion amount is small, A pipe volume determined based on a pipe length and a pipe diameter of each secondary gas system connected to the secondary gas supply path, and a gas supply flow rate and a minimum gas flow rate of the combustion equipment caused by the minute leakage, The determination can be made in accordance with the amount of combustion of the gas equipment constituting each secondary gas system.
Furthermore, an estimated pipe capacity corresponding to a gas device with a small combustion amount is calculated by calculating a pressure relaxation time determined for a gas device with a small combustion amount and a gas supply flow rate flowing through the secondary gas supply passage at that time. The optimum return safety confirmation time is determined for the secondary gas supply path corresponding to the gas equipment with a small amount of combustion by referring to the estimated piping capacity and the correlation corresponding to the gas equipment with a small amount of combustion. Therefore, a pipe volume determined based on a pipe length, a pipe diameter, and the like of each secondary gas system connected to the secondary gas supply path, and a gas appliance having a small combustion amount constituting each secondary gas system It is possible to refer to the estimated piping capacity and correlation corresponding to the above, and as a result, it is possible to individually obtain the optimum return safety confirmation time corresponding to the gas equipment with a small combustion amount for each secondary gas supply path. become able to. That is, it is possible to optimize the determination accuracy of the return determination of the secondary gas system based on the return safety confirmation time optimized for such a gas device with a small amount of combustion. As a result, the return safety confirmation time can be optimized.

According to the invention described in any one of claims 5 to 8, regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used, the secondary gas is measured when the pressure relaxation time is measured. Since the estimated pipe capacity is obtained by calculating the gas supply flow rate flowing through the supply path and the pressure relaxation time, the estimated pipe capacity corresponding to the gas supply flow rate due to the micro leak and the minimum gas flow rate of the combustion equipment is calculated on the secondary side. It can be determined according to the pipe volume determined based on the pipe length and the pipe diameter of each secondary gas system connected to the gas supply path, and the combustion amount of the gas equipment constituting each secondary gas system. Further, an estimated piping capacity corresponding to the minimum gas flow rate of the combustion equipment is calculated by calculating the pressure relaxation time determined for the gas equipment having a small combustion amount and the gas supply flow rate flowing through the secondary gas supply path at that time. ,
With reference to the correlation corresponding to the estimated pipe capacity and the minimum gas flow rate of the combustion equipment, the optimum return safety confirmation time for the secondary gas supply path corresponding to the gas equipment with a small combustion amount is determined. A pipe volume determined based on a pipe length, a pipe diameter, and the like for each secondary gas system connected to the secondary gas supply path,
It is possible to refer to the estimated piping capacity and correlation corresponding to the lowest gas flow rate of the combustion equipment in correspondence with the gas equipment with a small combustion amount constituting each secondary gas system, and as a result,
For each secondary gas supply path, it is possible to individually determine the optimal return safety confirmation time corresponding to the gas supply flow rate caused by the micro leak and the minimum gas flow rate of the combustion equipment or to the gas equipment with a small combustion amount become able to. That is, the gas supply flow rate flowing through the secondary gas supply path is monitored for the optimum time based on the return safety confirmation time, and the accuracy of the determination of whether or not the gas supply abnormality has been eliminated can be optimized. become.

According to the ninth aspect of the present invention, the secondary gas supply passage connected to the secondary gas supply passage is used regardless of whether a membrane flow sensor or an ultrasonic flow sensor is used. Referring to the pipe volume determined based on the pipe length and the pipe diameter for each side gas system, the estimated pipe capacity and correlation corresponding to the combustion amount of the gas equipment constituting each secondary gas system, and referring to FIG. The optimum return safety confirmation time can be obtained individually for each secondary gas supply path. Based on such optimized return safety confirmation time, the determination accuracy of the secondary gas system return determination can be improved. Optimization can be achieved, and as a result, the return safety confirmation time can be optimized.

According to the tenth aspect of the present invention, the pressure relaxation time obtained by the pipe capacity estimating means is equal to the case of using the membrane type flow sensor or the case of using the ultrasonic type flow sensor. By calculating the gas supply flow rate flowing through the secondary gas supply path at that time, the estimated pipe capacity can be obtained by using the pipe capacity estimating means,
By referring to the estimated pipe capacity and the table, it is possible to obtain the optimum return safety confirmation time for the secondary gas supply path using the return safety confirmation time calculation means. It is possible to refer to a pipe volume determined based on a pipe length, a pipe diameter, and the like for each secondary gas system, an estimated pipe capacity and a table corresponding to a combustion amount of a gas device constituting each secondary gas system. And as a result, 2
The optimum return safety confirmation time can be individually obtained for each secondary gas supply path. That is, it is possible to optimize the determination accuracy of the return determination of the secondary gas system based on the optimized return safety confirmation time. As a result, the return safety confirmation time can be optimized. You can plan.

According to the eleventh or twelfth aspect of the present invention, the gas shutoff provided in the gas supply path is used regardless of whether a membrane type flow sensor or an ultrasonic type flow sensor is used. By operating the valve to temporarily shut off the gas supply in the gas supply path, the gas equipment connected to the gas supply path and having a low combustion amount is operated and the secondary gas supply path at that time is operated. The gas pressure can be determined as the reference gas pressure. The reference gas pressure obtained in this way is used as a criterion for determining the gas pressure drop caused by the gas supply flow rate at the time of micro leakage, and the time required for the gas pressure to drop by a predetermined pressure from this reference gas pressure is estimated for the pipe capacity. The means obtains the pressure relaxation time, and the pipe capacity estimating means calculates the gas supply flow rate and the pressure relaxation time flowing through the secondary gas supply path when measuring the pressure relaxation time obtained by the pipe capacity estimating means. Since the capacity is determined, the estimated pipe capacity corresponding to the gas supply flow rate due to the micro leak and the minimum gas flow rate of the combustion equipment is calculated as 2
Corresponding to the pipe volume determined based on the pipe length, pipe diameter, etc. of each secondary gas system connected to the secondary gas supply path, and the amount of combustion of the gas equipment constituting each secondary gas system It becomes possible to determine. Further, the piping capacity estimating means calculates the pressure relaxation time determined for the gas appliance having a small amount of combustion and the gas supply flow rate flowing through the secondary gas supply path at that time to correspond to the minimum gas flow rate of the combustion equipment. Calculate the estimated pipe capacity to be performed, and refer to the table corresponding to the estimated pipe capacity and the minimum gas flow rate of the combustion equipment to determine the optimal return safety confirmation time for the secondary gas supply path corresponding to the gas equipment with a small amount of combustion. Since the return safety confirmation time calculating means is required, the pipe volume determined based on the pipe length and the pipe diameter of each secondary gas system connected to the secondary gas supply path, and each secondary gas It is possible to refer to the estimated piping capacity and table corresponding to the minimum gas flow rate of the combustion equipment corresponding to the gas equipment with a small combustion volume that constitutes the system, and as a result, each secondary side gas supply path caused by a small leak Gas supply flow Return safety confirmation time calculating means it is possible to determine separately the combustion minimum gas flow rate optimally made to correspond to the small gas appliances with or combustion amount to correspond to a return safety confirmation time of the equipment. That is, the return judgment of the secondary gas system is performed based on the return safety confirmation time optimized by the return safety confirmation time calculation means in correspondence with the gas equipment having a small combustion amount or the gas supply flow rate caused by the minute leakage. Can be optimized, and as a result, the return safety confirmation time can be optimized.

According to the thirteenth or fourteenth aspect of the present invention, no matter which gas pressure measuring sensor such as a membrane type flow sensor or an ultrasonic type flow sensor is used, the gas pressure is measured when the pressure relaxation time is measured. Since the pipe capacity estimating means calculates the estimated pipe capacity by calculating the gas supply flow rate flowing through the secondary gas supply path detected by the measurement sensor and the pressure relaxation time obtained by the pipe capacity estimating means, it may be caused by minute leakage. Pipe capacity determined based on the gas supply flow rate to be performed and the estimated pipe capacity corresponding to the minimum gas flow rate of the combustion equipment based on the pipe length, pipe diameter, etc. of each secondary gas system connected to the secondary gas supply path And the pressure relaxation time determined by the pipe capacity estimating means in correspondence with the gas equipment constituting each secondary gas system and corresponding to the gas equipment having a small combustion quantity. The pipe capacity estimating means calculates the gas supply flow rate flowing through the secondary gas supply path detected by the gas pressure measurement sensor to obtain an estimated pipe capacity corresponding to the minimum gas flow rate of the combustion equipment. With reference to the table corresponding to the minimum gas flow rate, the return safety confirmation time calculation means finds the optimal return safety confirmation time for the secondary gas supply path corresponding to the gas equipment with a small amount of combustion. Applicable to pipe volume determined based on the pipe length, pipe diameter, etc. of each secondary gas system connected to the secondary gas supply path, and gas equipment with low combustion volume that constitutes each secondary gas system As a result, it becomes possible to refer to the estimated pipe capacity and the table corresponding to the minimum gas flow rate of the combustion equipment, and as a result, the gas supply flow rate caused by the minute leakage and the minimum gas flow rate of the combustion equipment are determined for each secondary gas supply path. The return safety confirmation time calculation means can individually determine the optimal return safety confirmation time corresponding to the corresponding or the gas appliance having a small amount of combustion. That is, the security control means monitors the gas supply flow rate flowing through the secondary gas supply path detected by the gas pressure measurement sensor for an optimum time based on the return safety confirmation time, and evaluates whether the gas supply abnormality has been eliminated. It is possible to optimize the determination accuracy.

[Brief description of the drawings]

FIG. 1 is a functional block diagram for explaining an embodiment of an electronic gas meter for executing a gas shut-off return method according to the present invention.

FIG. 2 is a flowchart illustrating an embodiment of a gas shut-off return method performed by the electronic gas meter of FIG. 1;

FIG. 3 is a graph for explaining a state of a decrease in gas pressure in a gas pipe immediately after return of a shutoff valve.

FIG. 4 is a graph for explaining a state of measurement of a pressure relaxation time performed by using a gas pressure drop in a gas pipe immediately after a test interruption.

5 is a graph for explaining a relationship between a return safety confirmation time set in advance and an estimated pipe capacity calculated using a pressure relaxation time measured in FIG. 4 and a gas supply flow rate at that time.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Gas security device 11 ... Table 12 ... Piping capacity estimation means (microprocessor) 13 ... Gas supply path 13B ... Secondary side gas supply path 14 ... Return safety confirmation time calculation means (microprocessor) 20 ... Electronic gas meter 22 ... Combustion Control means (microprocessor) 24 ... Gas pressure measurement sensor 26 ... Gas shutoff valve 27 ... Security control means (microprocessor) 30, ..., 30 ... Gas equipment k ... Estimated piping capacity P ... Gas pressure P0 ... Reference gas pressure Q ... Gas supply flow rate Q0: Reference gas supply flow rate T: Recovery safety confirmation time ΔP: Gas pressure constant ΔT: Pressure relaxation time

Claims (14)

(57) [Claims] An abnormal supply of a gas supplied to a secondary gas system is detected to shut off the supply of the gas, and an abnormal supply of the gas supplied to the secondary gas system is detected to be released. In the gas shut-off resetting method of resetting the gas supply, an abnormality is detected in the gas flowing in the secondary gas supply path, and the gas supply is reset after the gas supply to the secondary gas supply path is cut off. When determining the return safety confirmation time, which is a monitoring period for evaluating whether or not the supply abnormality of the secondary side has been eliminated, the secondary side based on the pipe shape of the secondary side gas supply path downstream of the gas shutoff valve is determined. The correlation between the estimated pipe capacity calculated as the estimated value of the pipe capacity of the gas supply path and the return safety confirmation time is obtained in advance, and the measured value of the measured estimated pipe capacity is referred to by referring to the correlation. According to the actual measured value of the estimated pipe capacity Gas shutoff recovery method and obtains the serial return safety confirmation time. 2. An estimated pipe capacity calculated by estimating a pipe capacity of the secondary gas supply path based on a pipe shape of the secondary gas supply path downstream of a gas shutoff valve. A monitoring period for evaluating whether or not the gas supply abnormality has been resolved when the supply of gas in the secondary gas supply path is restored and the pressure in the pipe flowing through the secondary gas supply path is monitored. A step of previously obtaining a correlation of the return safety confirmation time, and the step of activating the gas shutoff valve provided in the gas supply path and temporarily stopping the supply of gas in the gas supply path. A pressure relaxation time which is a time required for the gas pressure in the secondary gas supply passage to decrease by a pressure difference of a preset gas pressure constant, and a gas supply flow rate flowing through the secondary gas supply passage at that time. Act Calculating the estimated pipe capacity, and calculating the optimum return safety confirmation time for the secondary gas supply path with reference to the estimated pipe capacity and the correlation. The method for resetting gas cutoff according to claim 1. 3. The method according to claim 2, further comprising a second step of operating a gas device connected to the gas supply path and having a small combustion amount to promote a combustion operation. 4. A gas supply flow rate at the time of combustion of the gas appliance having a small combustion amount is obtained as a reference gas supply flow rate.
4. The method according to claim 3, further comprising a third step of obtaining a gas pressure of the secondary gas supply path at that time as a reference gas pressure. 5. The method according to claim 3, further comprising a fourth step of operating the gas cutoff valve provided in the gas supply path to temporarily cut off the supply of gas in the gas supply path. Gas shutoff return method. 6. A fifth step of calculating the estimated pipe capacity at the time of executing the fourth step by calculating a gas supply flow rate flowing through the secondary gas supply path at the time of measuring the pressure relaxation time and the pressure relaxation time. 6. The method according to claim 2, wherein
The method for recovering from gas shut-down according to any one of the above items. 7. The return safety confirmation time corresponding to the pressure relaxation time obtained in the fifth step by applying the estimated pipe capacity obtained in the fifth step to the correlation previously obtained in the first step. 7. The method according to claim 6, further comprising a sixth step of calculating 8. A seventh step of monitoring a gas supply flow rate flowing through the secondary gas supply path for the return safety confirmation time and evaluating whether or not a gas supply abnormality has been eliminated. The gas shut-off resetting method according to any one of claims 2 to 7. 9. Detecting a supply abnormality of the gas supplied to the secondary gas system to shut off the gas supply, and detecting that the supply abnormality of the gas supplied to the secondary gas system is released. In the gas security device, the gas supply to the secondary side gas supply path is detected and an abnormality is detected, and the gas supply to the secondary side gas supply path is interrupted. When the return safety confirmation time, which is a monitoring period for evaluating whether or not the supply abnormality has been eliminated, is determined based on the pipe shape of the secondary gas supply passage downstream of the gas shutoff valve. Means for previously obtaining a correlation between the estimated pipe capacity calculated as an estimated value of the pipe capacity of the supply path and the return safety confirmation time, and applying the measured value of the measured estimated pipe capacity to the correlation to obtain Actual estimated pipe capacity Gas security apparatus characterized by comprising a means for determining the return safety check time in accordance with the value. 10. An estimated pipe capacity calculated by estimating a pipe capacity of the secondary gas supply path based on a pipe shape of the secondary gas supply path downstream of a gas shutoff valve. A monitoring period for evaluating whether or not the gas supply abnormality has been resolved when the supply of gas in the secondary gas supply path is restored and the pressure in the pipe flowing through the secondary gas supply path is monitored. A table that holds in advance the correlation of the return safety confirmation time, and that the gas supply valve in the gas supply path is operated to temporarily shut off the supply of gas in the gas supply path. A pressure relaxation time which is a time required for the gas pressure in the secondary gas supply passage to decrease by a pressure difference of a gas pressure constant set in advance, and a gas supply flow flowing through the secondary gas supply passage at that time A pipe capacity estimating means for calculating the estimated pipe capacity by calculating the following; and a return safety check time calculation for applying the estimated pipe capacity to the table to obtain an optimum return safety check time for the secondary gas supply path. The gas security device according to claim 9, comprising means. 11. The pipe capacity estimating means calculates the gas supply flow rate flowing through the secondary gas supply path and the pressure relaxation time at the time of measuring the pressure relaxation time to obtain the estimated pipe capacity. The gas security device according to claim 10, wherein the gas security device is used. 12. The return safety confirmation time calculation means applies the estimated pipe capacity obtained by the pipe capacity estimation means to the correlation previously obtained by the first means and obtains the correlation by the pipe capacity estimation means. 11. The gas security device according to claim 10, wherein the recovery safety confirmation time corresponding to the pressure relaxation time is obtained. 13. A gas supply amount is measured, a supply abnormality of a gas supplied to a secondary gas system is detected, and a supply of the gas is shut off, and a supply abnormality of a gas supplied to the secondary gas system is detected. In the electronic gas meter that detects the release of the gas and returns the gas supply, the gas security device, a combustion control unit that is connected to the gas supply path and activates a gas device with a small amount of combustion to promote a combustion operation, A gas pressure measuring sensor for determining a gas supply flow rate during combustion of the gas appliance having a small amount of combustion as a reference gas supply flow rate, and obtaining a gas pressure of the secondary gas supply path at that time as a reference gas pressure; 13. A gas shut-off valve for operating a gas shut-off valve provided in a passage to temporarily shut off gas supply in the gas supply passage. Electronic gas meter using a gas security system according. 14. A security control means for monitoring a gas supply flow rate flowing through the secondary gas supply passage for the return safety confirmation time and evaluating whether or not a gas supply abnormality has been eliminated. An electronic gas meter according to claim 13.