JP3421985B2 - Gas leak detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas leakage detection device.

[0002]

2. Description of the Related Art Conventional liquefied propane gas (hereinafter referred to as LP
A gas leak detection device for detecting a leak of a gas supply pipe including a buried pipe of a supply facility is a gas leak detection device that supplies gas to a plurality of gas consumers in an apartment house such as an apartment or an apartment. Therefore, as a gas leakage detection device used when a large amount of gas is required to be supplied at one time, for example, as disclosed in Japanese Patent Application Laid-Open No. 3-41300, it is possible to detect a minute flow rate according to the gas flow rate. / There is a switching-type gas leakage detection device that can switch to support large flow rate detection.

That is, as shown in FIG. 6, the LPG cylinder 1
A gas supply source such as the above and a gas intake of the condominium 2 are connected by a gas supply pipe 4, and the gas supply pipe 4 is provided with pressure regulators 5, 6 and a parent gas meter 7. Further, a valve (not shown) and the like are also provided, and a gas meter 8 and a valve (not shown) are provided in a pipe for supplying gas from the gas intake port to the gas consuming equipment of each house of the condominium 2.

A parent pressure regulator 6 is installed in the gas supply pipe 4b between the pressure regulator 5 on the LPG cylinder 1 side, which is a gas supply source, and the parent gas meter 7 which integrates the amount of gas supplied to the entire condominium 2. Further, the gas supply pipe 4b is provided with bypass gas flow paths 14a and 14b for connecting the inlet side and the outlet side of the parent pressure regulator 6 in a bypass route.

In the bypass gas flow paths 14a and 14b, a child pressure regulator 15 and a microcomputer gas meter 16 installed as a minute leak detection means near the gas supply source are provided in this order from the inlet side. . The adjustment pressure of the child pressure adjuster 15 is set higher than the adjustment pressure of the parent pressure adjuster 6. Further, the microcomputer gas meter 16 can accurately measure a minute flow rate (for example, 3 liters / hour or less) and has a minute leak detection function.
When there is a flow rate above a threshold value (for example, 3 liters / hour) continuously for a day, it is determined that leakage has occurred, and the fact is notified by an alarm means such as lighting an alarm lamp or ringing an alarm buzzer.

In the switching-type gas leakage detection device, the main part of which is configured as described above, the gas consumption amount is increased during the night or on consecutive holidays, that is, during the period when the gas is not used by the consumer or when the user is out. Almost disappears, or the above 3
In the case of an extremely small amount (compared to the case of using a large flow rate in normal times) such as liter / hour, the pressure of the gas supply pipe 4b increases and the parent pressure adjuster 6 closes to adjust the child pressure. Since gas flows only to the container 15 and the microcomputer gas meter 16, the microcomputer gas meter 16 monitors the minute flow rate of the gas flowing through the gas supply pipe 4b.

At this time, if the gas consumption is completely stopped and no slight leakage occurs, neither the parent pressure regulator 6 nor the microcomputer gas meter 16 detects the gas flow rate. In other words, the flow rate is 0
That is the detection result. On the premise that such a so-called zero flow rate condition occurs at least once during a relatively long period of time, such as 30 days, the master pressure regulator 6 is obviously used in this period, particularly in the microcomputer gas meter 16. When the flow rate continues to be detected even at a very small level without stopping even once, the determination means arranged inside the microcomputer gas meter 16
As described above, it is determined that the leak is a minute leak, and the fact is notified by an alarm means such as lighting an alarm lamp or ringing an alarm buzzer.

As described above, in the conventional technique, the minute flow rate gas leak detection is performed by disposing the minute flow rate measurement bypass device and the minute flow rate detection device such as the microcomputer gas meter 16 in a part of the gas supply path. I am trying.

[0009]

However, as described above, the child pressure adjuster 15 and the minute flow rate detecting device such as the microcomputer gas meter 16 are completely separate from the parent pressure adjuster 6 and the parent gas meter 7 and are dedicated. Since the bypass piping is additionally provided, the entire device becomes large and piping work etc. becomes very complicated,
There is a problem that the throughput of the work process is significantly reduced and the cost is increased.

Further, as the microcomputer gas meter 16 used as the above-mentioned minute flow rate detecting device, a mechanical type volumetric flow meter such as a so-called conventional membrane type was used, but in the membrane type gas meter. Since there is a restriction on the minimum measurable flow rate in general, there is a problem that the flow rate below that cannot be detected. That is, for example, when the flow rate of at least one cycle of the membrane gas meter is 0.7 liter, and when a gas of a flow rate corresponding to this flow rate leaks, the occurrence of the gas leak should be immediately detected at the time of occurrence. I can't. For example, when there is a pipe leak that produces a minute gas flow rate of 3 liters / hour, the flow rate measurement can be completed by the membrane meter whose flow rate in one cycle is 0.7 liter. (0.7 ÷ 3) × 60 = 14 minutes, and the measurement cannot be performed within 14 minutes. In other words, unless gas use is stopped for 14 minutes or more in the above-mentioned apartment house for 30 days, it cannot be detected as gas use stop. There has been a problem that even the operation for detecting minute leaks cannot be performed accurately. Alternatively, even if such an operation for detecting minute leakage can be performed, the flow rate at that time cannot be detected instantaneously, so that there is a problem that rapid measurement cannot be performed.

Therefore, in order to realize the above-mentioned instantaneous detection of a minute flow rate with a simple and compact device configuration,
For example, an ultrasonic measurement method in which ultrasonic waves are propagated in a gas flow and the propagation time at that time is measured, and the instantaneous flow rate at each time is measured based on that, or a heating wire is placed in the gas flow to upstream of the ultrasonic measurement method. A so-called instantaneous flow velocity measurement sensor, such as a thermal mass measurement method that detects a temperature change (temperature difference) between the downstream side and the downstream side and measures the instantaneous flow rate at each time, is referred to as a minute flow rate detection means, that is, the above example. The inventors of the present application have found that the microcomputer gas meter 16 is suitable for use.

Further, when such an instantaneous flow velocity measuring sensor is used, in order to accurately measure the above-mentioned minute flow rate value, the gas flow rate measuring sensor for measuring the gas flow is arranged in the gas guide. The smaller the cross-sectional area (cross-sectional size) of the passage, the larger the flow velocity of the gas flowing through the passage becomes, and the more accurate the measurement becomes. Therefore, it is required that the cross-sectional area of the passage be as small as possible. Therefore, in order to accurately measure the value of such a minute flow rate, it is necessary to separately provide a dedicated gas passage for conducting gas.

That is, in addition to the mainstream piping having a capacity (cross-sectional diameter or cross-sectional area) capable of flowing a gas flow rate at the time of general gas consumption, a certain gas flow velocity corresponding to the above-mentioned minute gas flow rate. It has been devised to provide a conducting path for measuring a minute flow rate, which has a minute capacity (cross-sectional diameter or cross-sectional area) such that the speed can be secured, in one microcomputer gas meter 16. In this way, two lines of gas pipes, a gas pipe for a large flow rate for flowing a large flow rate gas and a gas pipe for a small flow rate for flowing a small flow rate gas, or in other words, a main pipe for a large flow rate. This requires a pipe for branching from that to be used for measuring a small flow rate, which corresponds to a small flow rate. This structure does not basically change even if the microcomputer gas meter 16 and the child pressure regulator 15 are miniaturized. Two such gas pipe flow paths are required. However, the two gas pipe flow paths are connected to one microcomputer gas meter 16
By disposing it in such a flow rate measuring device, and since one of them may be a small pipe capable of flowing a minute flow rate, the overall structure thereof can be dramatically reduced in size.

However, even if such two gas pipe flow paths are provided in the microcomputer gas meter 16, it is possible to measure with the instantaneous flow velocity measuring sensor for measuring the minute flow rate as described above. In order to do so, the gas flow rate value in a flow rate range that is within a minute flow rate range that corresponds to the minute leakage and that exceeds the flow rate range could not be measured by this device. As a result, for the gas flow rate values in the medium to high flow rate range beyond the minute flow rate range corresponding to the above-mentioned minute leakage, the microcomputer gas meter 1 described above is used.
Since it has to be measured by a gas flow rate measuring means for medium to high flow rate range different from the device like 6, the microcomputer gas meter 16 can be downsized as described above. In addition to the microcomputer gas meter 16, gas flow rate measuring means must be additionally provided, which eventually leads to a problem that the configuration of the entire apparatus becomes complicated.

Moreover, when a gas flow rate measuring means for such a medium to high flow rate range is separately provided and the gas flow rate measuring means measures the gas flow rate value in the above-mentioned medium to high flow rate range, ~ It is expected that it can be most easily used as a gas flow rate measuring means for high flow rate range and can accurately measure the gas flow rate value in the medium to high flow rate range by integrating the cumulative gas consumption. Is a gas meter 7 used for
Further, it is considered that the gas flow rate measuring means used therefor is particularly suitable. However, in such a gas meter 7, a volume flow rate measuring method called a so-called membrane type flow meter is the most conventional gas flow rate measuring means. It is commonly used. Therefore, it is often difficult to measure the instantaneous gas flow rate instantaneously as described above.

The gas meter 7 as described above is generally arranged for each user's residence and can measure the gas flow rate for each user. However, the gas meter 7 like the microcomputer gas meter 16 (or gas supply) is used. The position where the microcomputer gas meter 16 is arranged because there is a definite functional difference in that the total flow rate cannot be measured as in the case of the gas flow rate measuring device arranged in the regulators 5, 6 closer to the source). There is a definite problem that it is impossible to measure the gas flow rate under the same conditions as the measurement in.
That is, for example, in order to measure the total gas flow rate value used in the gas supply system in an apartment house, the microcomputer gas meter 16 is arranged in the pipe part before the gas is distributed and supplied to each user. It is practically impossible except to measure the gas flow rate at a certain position, but since the gas meter 7 is generally arranged at the portion closest to the downstream side, the total gas flow rate that can be measured only at the upstream side as described above. The value could not be measured by the gas meter 7.

The present invention has been made to solve such a problem. The present invention relates to a gas leakage detection device having a minute leakage detection function for detecting a gas leakage at a minute flow rate, which is equipped with an instantaneous flow velocity (flow rate) measurement sensor and is sufficiently accurate and reliable for measuring minute flow rate, that is, minute gas. It is possible to detect leaks, and it is possible to measure not only minute flow rates but also medium to high flow rates while further downsizing the overall device and simplifying the structure. It is an object to provide a detection device.

[0018]

First, the gas leakage detection device of the present invention is provided on a gas supply pipe for conducting gas supplied from a gas supply source or on a serial extension of the gas supply pipe. A parent pressure regulator, a bypass gas flow passage having an inlet connected to an upstream side of the parent pressure regulator so as to bypass the parent pressure regulator, and an outlet connected to a downstream side thereof, and the bypass gas flow passage And a child pressure adjuster that is adjusted to a higher adjustment pressure than the parent pressure adjuster, and is arranged in the bypass gas flow path on the downstream side of the gas flow with respect to the child pressure adjuster. The instantaneous flow velocity of the gas
A first instantaneous velocity measuring sensor for measuring
A gas leak measuring device having a gas flow rate measuring means, further comprising: a downstream side and the outlet of the parent pressure regulator;
A main gas flow channel connected to the downstream side of, disposed in the main gas flow channel in the gas flowing through the main gas flow passages
Instantaneous between the second moment the flow rate measuring the and a second gas flow rate measuring means comprising using a flow rate measuring sensor, further the
In addition, the second gas flow rate measuring means is configured to detect the first instantaneous flow rate.
Same type and same range abilit
And measuring the flow velocity of the gas flowing through the main gas flow passage.
Second instantaneous flow velocity measurement with measurable rangeability
A second gas flow rate measuring means using a sensor,
In addition, the main gas conduction flow path is not connected to the bypass gas flow path.
Cross-sectional area larger than area or proper pressure when using normal gas
It is possible to secure a pressure above the predetermined pressure as
It is possible to measure with the second instantaneous flow velocity measurement sensor
The flow velocity above the minimum flow velocity during normal rangeability is usually
Main gas with a cross-sectional area less than that which can be secured during use
It is characterized in that it is a flow path.

That is, the main gas flow passage is capable of flowing a gas flow having a flow rate exceeding the gas flow rate in the range of a minute to low flow rate range in which conduction by the bypass gas flow path, that is, a medium to large flow rate. Therefore, by providing the second gas flow rate measuring means in such a main gas flow passage as described above, it is possible to measure the instantaneous flow rate in the medium to large flow rate range flowing through the main gas flow passage. . And as a result, when the instantaneous flow rate of the gas flow in the medium to large flow rate range is continuously flowing for a predetermined time period that is in a range of a predetermined flow rate value that is predetermined, By detecting this, it is possible to determine that a medium to large flow rate of gas leak has occurred, which exceeds the so-called minute flow rate leak detected by the first gas flow rate measuring means. Further, since it is possible to measure a gas flow rate of medium to high flow rate, a gas flow rate integrating device such as the conventional parent gas meter 7 can be omitted altogether, and the size and simplification of the device as the entire gas supply system can be reduced. It can be effectively realized.

Further, as pointed out above as a conventional problem, it was impossible for the conventional membrane type meter to instantaneously and quickly measure the flow rate. However, according to the present invention, by using the instantaneous flow rate measurement sensor capable of measuring the instantaneous flow rate of the gas as the gas flow rate measurement unit arranged in the bypass gas flow path downstream of the child pressure regulator to measure the minute flow rate, It is possible to instantly measure the flow rate at each time instantly.

In addition, the instant flow rate measuring sensor used in the gas leakage detecting device according to the present invention can be remarkably miniaturized in its main body as compared with the conventional membrane type sensor, so that the minute leakage detecting device can be used. The gas flow rate measuring means can be downsized, and as a result, the gas leak detection apparatus as a whole can be downsized.

Here, the above-mentioned instantaneous flow rate measuring sensor according to the present invention is a fluid-type sensor that changes according to the flow rate of a gas flow, which is called a so-called guessing method (or an estimation method in literature). A method that measures various physical quantities and calculates the gas flow rate based on the measured values, that is, a differential pressure flow meter pressure method that measures the dynamic pressure due to the gas flow, and an area flow rate measurement method that measures the viscous resistance of the gas flow. , A turbine flow rate measurement method that measures the power of the gas flow to move the turbine blades, a vortex flow rate measurement method that measures the frequency of the vortex generated in the gas flow, and the propagation time of ultrasonic waves propagated in the gas flow. Alternatively, an ultrasonic flow rate measuring method for measuring the propagation velocity or the like is particularly suitable. Alternatively, a thermal mass flow rate measuring method in which a heating wire is arranged in a gas flow and a temperature change before and after the heating wire is measured can be preferably used. In any case, if a factor (physical quantity) related to the flow rate of the gas flow is measured and the flow rate per differential unit time of the gas flow is obtained based on it, the instantaneous flow rate measurement sensor can be used as various instantaneous flow rate measurement sensors. Needless to say, can also be suitably used. That is, after measuring the instantaneous flow velocity v, the instantaneous flow rate Q = v · S can be obtained by multiplying the flow velocity v by the cross-sectional area S of the gas flow path.

[0023]

Further, in addition to the above-mentioned actions and effects,
The first instantaneous flow velocity measuring sensor used in the first gas flow rate measuring means is also used in the second gas flow rate measuring means in the second.
The same rangeability sensor can also be used for the instantaneous flow velocity measurement sensor of.

Moreover, the main gas flow passage can secure a pressure larger than a cross-sectional area larger than the cross-sectional area of the bypass gas flow passage or a predetermined pressure or more as an appropriate pressure during normal use on the downstream side. Since the main gas flow passage has a cross-sectional area that is equal to or smaller than the cross-sectional area that can ensure a flow velocity that is equal to or higher than the minimum flow velocity that can be measured by the second instantaneous flow velocity measurement sensor during normal use, it is predetermined as an appropriate pressure during normal use. Since a pressure equal to or higher than the predetermined pressure can be secured on the downstream side and a flow velocity equal to or higher than the minimum flow velocity measurable by the second instantaneous flow velocity measurement sensor can be secured during the normal use, the second instantaneous flow velocity measurement sensor It is possible to measure the flow velocity of the gas flow in normal use that flows through the main gas flow passage, and based on this flow velocity, the gas flow rate at that time (in particular, such a medium to large cross-sectional area It is possible to measure the gas flow rate) of medium to large flow rate.

Here, the merits of the above-described first technique will be described more specifically. The first instantaneous flow velocity measuring sensor and the second instantaneous flow velocity measuring sensor are of the same type as at least their hardware. Since the above sensor can be used, the first instantaneous flow velocity measurement sensor and the second instantaneous flow velocity measurement, which are one of the particularly important parts of the constituent parts constituting the main part of the gas leakage detection device according to the second aspect of the invention. As a sensor, only one type of sensor can be used in two places, the main gas flow passage and the bypass gas flow passage, as described above. Therefore, since it is sufficient to prepare only one type of sensor as the instantaneous flow velocity measuring sensor, different types, that is, different types, for measuring gas flow rates corresponding to different flow rate regions in the above two places, respectively, as in the conventional case. According to the present invention, the complexity of using two types of instantaneous velocity measurement sensors having rangeability can be completely eliminated.

[0027] Second, the gas leakage detection device of the present invention, the gas leakage detection device of the mounting the first reporting, child pressure regulator and the master pressure regulator and bypass gas flow path and the main gas flow stream The passage, the first gas flow rate measuring means, and the second gas flow rate measuring means are integrally arranged.

[0028] That is, according to the present invention, as described in the first SL mounting technique, since it is possible to first reduce the dramatic miniaturization of the first and second gas flow rate measuring means,
A structure centered on it, that is, the child pressure regulator, the bypass gas flow path, the first and second gas flow rate measuring means, and the like can be integrated to further reduce the size of the apparatus, and If they can be made compact, it is possible to arrange them integrally with the parent pressure regulator, and as a result, the child pressure regulator, parent pressure regulator, bypass gas flow path, first and second By integrating the gas flow rate measuring means and the like in an extremely compact manner, it is possible to realize a dramatic reduction in size of the gas leakage detection device as a whole.

Fourthly, the gas leakage detecting device of the present invention is the gas leakage detecting device according to the first or second aspect , wherein the first gas flow rate measuring means or the second gas flow rate measuring means respectively sets a predetermined value. Gas leakage determination means for determining that a gas leakage has occurred downstream of the parent pressure regulator when it is detected that the flow rate of gas is continuously flowing for a predetermined time, and the gas leakage determination An alarm generating means for alarming the occurrence of the gas leakage by at least one of a visual medium and an audible medium when it is determined by the means that the gas leakage has occurred on the downstream side of the parent pressure regulator. It is characterized by having.

That is, in the flow rate range measured by the first gas flow rate measuring means or in the flow rate range measured by the second gas flow rate measuring means which is different from the flow rate range, a minute flow rate gas leak or a medium to large flow rate gas leak occurs. When detected, the alarm generating means can issue an alarm of gas leakage based on the detected result. That is, according to the present invention, it is possible to obtain an advantage that not only the minute flow rate gas leak but also the gas leak can be detected over a wider flow rate range.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a gas leakage detection device according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a main part of a configuration of a gas leakage detection device according to the present invention, and FIG. 2 is a diagram showing a schematic configuration of a main part of an entire gas supply system in which it is incorporated and used.
3 and 4 are schematic flowcharts showing the operations of gas flow rate measurement, gas leak determination, and gas leak warning, which are the main parts of the operation.

In this gas leakage detection device, a gas container which is one type of gas supply source, that is, a gas supply pipe 4 for conducting gas supplied from an LPG cylinder 1 and a pressure regulator 5 for the gas supply pipe 4 are provided. A parent pressure regulator 6 provided on the downstream side of a pipe 4 ′ connected in series via an extension thereof and an upstream side of the parent pressure regulator 6 so as to bypass the parent pressure regulator 6. To a bypass flow passage inlet 13a, and a downstream side to which a bypass flow passage outlet 13b is connected, and bypass gas flow passages 14a and 14b provided in the middle of the bypass gas flow passages 14a and 14b. Child pressure regulator 15 that is adjusted to a higher adjustment pressure than the adjustment pressure of 6, and the bypass gas flow paths 14a and 14b
Of the first gas flow rate measuring means 12a, 12b arranged downstream of the child pressure regulator 15 for measuring the instantaneous flow velocity vb of the gas 101, and the gas flow velocity vb measured by the gas flow velocity measuring means 101 is continuously flowing within a predetermined flow velocity range (described later) for a predetermined time, the parent pressure A gas leak detection device capable of determining that a gas leak has occurred on the downstream side of the regulator 6, and is further connected to the downstream side of the parent pressure regulator 6 and has the bypass gas flow paths 14a, 14b. Cross-sectional area S
a main gas passage 11 having a cross-sectional area Sm larger than b and arranged as a gas passage different from the bypass gas passages 14a and 14b; Second instantaneous flow velocity measuring sensors 12c, 1 for measuring the instantaneous flow velocity vm of the gas flowing through the main gas flow passage 11
The second gas flow rate measuring means 102 using 2d is provided.

Further, the second gas flow rate measuring means 102 includes the first instantaneous flow velocity measuring sensor 12a,
The second gas flow rate measuring means 102 uses the second instantaneous flow velocity measuring sensors 12c and 12d having rangeability capable of measuring the same instantaneous flow rate range as 12b.

Furthermore, the main gas passage 11 is
A cross-sectional area larger than the cross-sectional area Sb of the bypass gas flow paths 14a and 14b, or a pressure equal to or higher than a predetermined pressure as an appropriate pressure when using normal gas can be secured on the downstream side, and the second instantaneous flow velocity measurement can be performed. Sensor 12c, 1
It has a cross-sectional area Sm that satisfies the condition that the flow velocity is equal to or higher than the minimum flow velocity in the measurable rangeability of 2d or less when the normal gas is used.

Further, the child pressure regulator 15, the parent pressure regulator 6, and the bypass gas flow passage 14 are provided.
a, 14b, the main gas communication flow path 11, the first gas flow rate measuring means 101, and the second gas flow rate measuring means 102 are integrated into the parent pressure regulator 6.
In particular, in this embodiment, they are arranged on the front surface and inside the outer shell body.

Further, the first gas flow rate measuring means 101 or the second gas flow rate measuring means 102 respectively detects that a gas having a predetermined flow rate is continuously flowing for a predetermined time. And the parent pressure regulator 6
When the gas leakage determination means 103 determines that a gas leakage has occurred on the downstream side of the parent pressure regulator, and the gas leakage determination means 103 determines that a gas leakage has occurred on the downstream side of the parent pressure regulator 6, An alarm generation means 104 for alarming the occurrence of gas leakage by both a visual medium and an audible medium is provided.

In the present embodiment, the above-mentioned first
As the instantaneous flow velocity measuring sensors 12a and 12b and the second instantaneous flow velocity measuring sensors 12c and 12d, ultrasonic waves are transmitted and received between a set of two ultrasonic transducers, and a gas having a propagation time or a propagation velocity is used. The instantaneous flow velocity measurement sensor was used to detect the change caused by the flow and measure the instantaneous flow velocity or the instantaneous flow rate of the gas flow based on the change. Moreover, both the first instantaneous flow velocity measurement sensors 12a and 12b and the second instantaneous flow velocity measurement sensors 12c and 12d use the same type of instantaneous flow velocity measurement sensor having the same measurement rangeability.

Further, more specifically, the alarm generating means 104 uses a red flashing lamp as a visual medium, and uses a voice synthesis LSI and a speaker device as an audible medium to "gas leak." An alarm such as "is occurring" is generated by synthetic voice (all are not shown). Such a red flashing light or voice synthesis LSI
As for the structure and function of the speaker device and the like, a conventional device can be preferably used, and therefore detailed description and illustration thereof are omitted here.

Here, regarding the cross-sectional area Sm of the main gas conducting passage 11 described above, first, in order to secure the gas flow rate required during normal use of gas in the entire gas supply system, a certain amount of disconnection is required. Area is required. Therefore, first of all, the necessary condition for the cross-sectional area Sm is larger than the cross-sectional area Sb of the bypass gas flow paths 14a, 14b formed for the purpose of flowing the minute flow rate suitable for the measurement of the minute flow rate. However, if the cross-sectional area Sm of the main gas passage 11 is increased without limit, a large amount of gas flow can be flowed without limit. . But L
Since the instantaneous gas flow rate supplied from the PG cylinder 1 has a limit (predetermined appropriate value), this cross-sectional area S
If m is made too large, it becomes impossible to secure an appropriate value of the pressure of the gas supplied to the downstream side, that is, the user side. At the same time, the flow velocity of the gas flowing through the main gas passage 11 having the large cross-sectional area Sm is an order of magnitude higher than that of the gas flowing through the small cross-sectional region Sb such as the bypass gas flow passages 14a and 14b. The flow velocity becomes slow, and the first instantaneous flow velocity measurement sensor 12a, 1
In some cases, the measurable range ability of 2b may make measurement impossible. Therefore, it is desirable to set the cross-sectional area Sm of the main gas flow passage 11 as described above.

Incidentally, FIG. 5 is a front view showing a more specific outline of the main part of the hardware structure of the gas leakage detection device according to the present invention as described above. That is, as shown in FIG. 5, on the front surface of the main body of the parent pressure regulator 6, a child pressure regulator 15, not shown (in the front view of FIG. 5, it is hidden by the child pressure regulator 15 and the like and is not visible). Therefore, the bypass gas flow paths 14a and 14b, the minute flow rate sensor box 200 containing the first instantaneous flow velocity measurement sensors 12a and 12b, which are the sensor portions of the first gas flow rate measurement means 101, and the first gas described above. Flow rate measuring means 101
Based on the flow rate vb and vm measured by the respective numerical operation units of the flow velocity measuring sensors 12c and 12d, that is, qb = vb * Sb and qm = v, respectively.
An arithmetic circuit system (not shown) that calculates m × Sm and calculates gas flow rates qb and qm at that time, and a gas leakage determination means 103 by using a printed wiring circuit, an electronic device, an integrated circuit, or the like as hardware, An electronic circuit system in which the electronic circuit portion of the alarm generating means 104 is specifically constructed, and an arithmetic circuit system box 100 accommodating a red blinking light for issuing an alarm, a voice synthesizer, a speaker device, etc. are additionally provided. Has been done. And the minute flow rate sensor box 2
First instantaneous flow velocity measuring sensor 12 housed in 00
It goes without saying that a and 12b are connected to the numerical operation portion, that is, the arithmetic circuit system housed in the arithmetic circuit system box 100, by wiring not shown.

Further, the second instantaneous flow velocity measuring sensor 1 which is the sensor portion of the second gas flow rate measuring means 102.
Normal flow rate sensor box 300 containing 2c, 12d and main gas flow passage 11 (not shown in FIG. 4)
Is arranged directly below the parent pressure adjuster 6. Needless to say, the main body of the pressure regulator is housed inside the outer casing of the parent pressure regulator 6.

As described above, most of the hardware of the gas leakage detection device according to the present invention is attached to and integrated with the parent pressure regulator 6, so that the overall configuration is dramatically reduced in size. be able to. Moreover, in terms of the overall configuration, as compared with the overall configuration of the conventional one shown in FIG. 6, the microcomputer gas meter 16 and the parent gas meter 7, which are installed separately, are eliminated by the technique of the present invention ( Therefore, according to the technique of the present invention, it is possible to effectively further simplify the configuration.

Next, the operations of the gas flow rate measurement, gas leak determination, and gas leak alarm, which are the main parts of the operation of the gas leak detection apparatus according to the present invention, will be described with reference to the outline flowcharts of FIGS. 3 and 4. To do. First, the first gas flow rate measuring means 101 and the first instantaneous flow rate measuring sensors 12a, 12b for measuring the instantaneous flow rate vb of a so-called minute flow rate of gas flow passing through the bypass gas flow paths 14a, 14b will be described. As shown in, the gas flow rate becomes low,
The gas pressure P at that time is the set pressure R of the child pressure regulator 15.
Above 3 the gas flow will be in the bypass gas passage 14
Pass a and 14b. Then, every time the time (T) reaches a predetermined constant measurement cycle T0 (Y of s1), the instantaneous flow velocity vb of the gas flowing through the bypass gas flow passages 14a and 14b at that moment is set to the first instantaneous flow velocity measurement sensor. 12a, 12b
Is measured (s2).

Then, the gas leakage determining means 103 determines the measured instantaneous flow velocity vb to be a predetermined threshold flow rate, for example, 3 liter / hour or less to 0.
A comparison is made with a threshold flow rate vL≤vb≤vth defined as a minute leak flow rate of 5 liters / hour or more (s3). Here, it goes without saying that a numerical value that is not 0 and can be determined to be a minute flow rate is used as VL.

When the instantaneous gas flow velocity measured at this time is a value other than the above threshold flow rate range vL≤vb≤vth and particularly exceeding vth, the gas is in use. Is determined as. However, the measured instantaneous gas flow velocity vb is within the above-mentioned threshold flow rate range (vL≤vb≤v
th), it is determined that a minute flow rate other than 0 as described above is flowing, and the measurement time point is used as a starting point, for example, a predetermined period Dth such as 30 days.
The number of days (Dx) that such a minute flow rate was detected
Is counted (s4).

However, when the gas flow velocity vb is out of the threshold flow rate range vL≤vb≤vth as indicated by N in s3 during the counting of the number of days (Dx), and particularly When the value at that time is less than vL (that is, when vb <vL), the count value Dx of the number of days that has been counted until then is reset to the initial value (Dx = 0). Then, the process returns to the original s1 (s9).

This is because, for example, when something like a pilot fire of a gas water heater is in use and it is about to be erroneously detected as a minute gas leak, if the use is stopped, it is immediately detected. It goes without saying that the detection and reset as described above can prevent the malfunction as the detection of the minute gas leakage. The threshold flow rate range vL to vth is a minute flow rate that flows only when a minute leak occurs, and the probability of such a minute gas flow is almost zero during normal use of the gas as described above. It is set to a range of values of minute flow rates that are close to each other, but are not zero (that is, the gas flow is not completely stopped).

When the count value Dx on the day when the minute flow rate is detected is equal to or greater than the period Dth (s5
Y), the gas leakage determination means 103 determines that a slight leakage has occurred (s6). Subsequently, in response to the determination of the occurrence of the minute leak, the alarm generation means 104 issues an alarm to that effect (s7).

After that, when gas leak is confirmed and the alarm is reset (Y in s8), the apparatus returns to s1 and starts the same operation as above. next,
The second gas flow rate measuring means 102 for measuring the instantaneous flow velocity vm of the gas flow and the second instantaneous flow velocity, for example, when a gas leakage of a medium to large flow rate near the gas supply source is detected and an alarm is issued. The operation of the measuring sensors 12c and 12d will be described. As shown in FIG. 4, the gas flow rate becomes a medium to large flow rate, and the gas pressure P at that time becomes lower than the set pressure R3 of the child pressure regulator 15. When the gas flow passes through the parent pressure regulator 6 and passes through the main gas flow passage 11, the time (T) elapses every predetermined measurement cycle T0 (Y of s1). Instantaneous main gas flow path 11
The second instantaneous flow velocity measuring sensors 12c and 12d measure the instantaneous flow velocity vm of the gas flowing through the gas (s2). The measurement cycle T0 is the same as the first gas flow rate measuring means 1 described above.
Although the same cycle as the measurement cycle T0 used in 01 or a different cycle may be used, the second instantaneous flow velocity measurement sensors 12c and 12d are substantially the first instantaneous flow velocity measurement sensors 12a and 12b. Since it uses the sensor with the same function as above, it is better to unify both in the same measurement cycle, both in terms of usage and processing of the measured data. It can be said that it is desirable because it has the advantage that it can be realized.

Subsequently, the gas leakage determining means 103 compares the measured instantaneous flow velocity vm with a predetermined threshold flow rate vth-Hs (s3). For example, a threshold flow rate v defined as a flow rate of 3 liters / hour or more
The range of th-H ≦ vm is compared with the measured instantaneous gas flow velocity vm.

At this time, if the instantaneous gas flow velocity vm is not in the threshold flow rate range vth-H <vm, it is determined that the gas is in use (N in s3). However, here, when the instantaneous gas flow velocity vm is a value exceeding the threshold flow rate vth-H (that is, vth-H <vm) (Y in s3), the gas leakage determination means 103 then It is determined that a medium to large flow rate of leakage gas is flowing, that is, a medium to large amount of gas leakage is occurring (s4).

When such a determination is made, upon receipt of the determination, the alarm generating means 104 issues an alarm to that effect (s5). And after that, a gas leak was confirmed,
When the alarm is reset (Y in s6), the apparatus returns to s1 and repeats the same operation as above.

In each of the schematic flow charts of FIGS. 3 and 4, one endless loop is drawn as a whole so that the operation is repeated. However, this is not shown, for example, the replacement life of this device. It is needless to say that the stop operation can be performed in the case where the operation is stopped in the forced interrupt mode or the like due to the arrival of a message such as "1. However, since the gas leakage detection device according to the present invention essentially repeats the above-described gas leakage detection function in an infinite loop shape without rest during its continuous use, regarding such trivial matters, Needless to say, the description and the illustration are omitted for simplification.

In the above embodiment, an example in which the second gas flow rate measuring means 102 is used for medium to high flow rate gas leak detection has been described.
The detection is not limited to such gas leakage detection. In addition to this, for example, it is used instead of the parent gas meter 7 arranged near the conventional gas supply source as shown in FIG. 6, and it is integrated in time based on the gas flow velocity v measured there. It is needless to say that it can be used to obtain the total integrated gas consumption.

[0055]

As has been clearly described in the above detailed description, according to the present invention, an instantaneous flow velocity (flow rate) measuring sensor is provided in a gas leakage detection device equipped with a minute leakage detection device for detecting gas leakage at a minute flow rate. It is possible to realize a highly accurate and reliable measurement of a minute flow rate, that is, to detect a minute gas leak, while further reducing the overall size of the device and simplifying the structure. It is possible to provide a gas leakage detection device capable of measuring not only the above but also a medium to large flow rate.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a configuration of a gas leakage detection device according to the present invention.

FIG. 2 is a diagram showing a schematic configuration of a main part of the entire gas supply system in which the gas leakage detection device according to the present invention is incorporated and used.

FIG. 3 is a schematic flowchart showing operations of gas flow rate measurement, gas leak determination, and gas leak alarm, particularly by the first gas flow rate measuring means 101, in the gas leak detection apparatus according to the present invention.

FIG. 4 is a schematic flowchart showing the operations of gas flow rate measurement, gas leak determination, and gas leak alarm, particularly by the second gas flow rate measurement means 102 in the gas leak detection apparatus according to the present invention.

FIG. 5 is a front view showing a more specific overview of the main part of the hardware structure of the gas leakage detection device according to the present invention.

FIG. 6 is a diagram showing an outline of a configuration of a gas leak detection device for detecting a leak in a gas supply pipe including a buried pipe of a conventional liquefied propane gas supply facility.

[Explanation of symbols]

1 ... LPG cylinder 4 ... Gas supply piping 5 ... Pressure regulator 6 ... Parent pressure regulator 11 ... Main gas flow passage 12a, 12b ... First instantaneous flow velocity measuring sensor 12c, 12d ... Second instantaneous flow velocity measuring sensor 14a, 14b ... Bypass gas flow path 15. Child pressure regulator 101 ... First gas flow rate measuring means 102 ... Second gas flow rate measuring means 103 ... Gas leakage determination means 104 ... Alarm generating means

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-8-43246 (JP, A) JP-A-3-41300 (JP, A) JP-A-8-128914 (JP, A) JP-A-9- 145526 (JP, A) JP-B 6-43906 (JP, B2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01M 3/00 G01F 1/00 G01M 3/26

Claims (3)

(57) [Claims] 1. A master pressure adjuster provided on a gas supply pipe for conducting gas supplied from a gas supply source or on a series extension of the gas supply pipe, and the master pressure adjuster bypassing the master pressure adjuster. A bypass gas flow path having an inlet connected to the upstream side of the parent pressure regulator and an outlet connected to the downstream side, and a regulated pressure higher than the regulated pressure of the parent pressure regulator provided in the bypass gas channel. And an instantaneous flow velocity of the gas , which is arranged downstream of the child pressure regulator of the bypass gas flow path from the child pressure regulator.
A first instantaneous velocity measuring sensor for measuring
And a gas leak detecting device having a gas flow rate measuring means, further comprising: a gas leakage detecting device connected to a downstream side of the parent pressure regulator and a downstream side of the outlet.
A main gas flow passage is continued, the main arranged in the gas conducting passages in, the main gas flow passage second formed by using the second moment flowmetry sensor for measuring the instantaneous between the flow rate of the gas flowing and a gas flow rate measuring means
And further, the second gas flow rate measuring means is
Same type and same range
Flow velocity of the gas flowing through the main gas flow passage
Second instantaneous flow velocity with rangeability that can measure
A second gas flow rate measuring means using a measurement sensor , wherein the main gas conducting flow path is the bypass gas flow path.
Cross-sectional area larger than the cross-sectional area of or suitable for normal gas use
Confirm a pressure above the predetermined pressure on the downstream side.
The second instantaneous velocity sensor can measure
The flow velocity above the minimum flow velocity in the rangeability
A main unit with a cross-sectional area less than that which can be secured during normal use
Gas leakage detection device characterized by gas flow passage
Place 2. The gas leak detection device according to claim 1.
The child pressure regulator and the parent pressure regulator and the bypass
Gas passage and the main gas flow passage and the first
Gas flow rate measuring means and second gas flow rate measuring means
Gas leakage detection characterized by being integrated
apparatus. 3. The gas leakage detection device according to claim 1 or 2.
In the above , further, the first gas flow rate measuring means or the second gas flow rate
Depending on the measuring means, each gas with a predetermined flow rate for a predetermined time
If a continuous flow is detected over the
Determines that a gas leak has occurred downstream of the parent pressure regulator
Gas leakage determining means, and the gas leakage determining means downstream of the parent pressure regulator.
If it is determined that a gas leak has occurred in the
Minimize the occurrence of leaks in visual or auditory media
Also has an alarm generating means for issuing an alarm on either side.
And a gas leakage detection device.