JP3148056B2 - Used gas appliance discriminator - 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 appliance discriminating apparatus for discriminating the type of gas appliance in a gas supply system for supplying gas to the gas appliance via a gas meter, and more particularly to a gas governor (pressure adjustment). Device for discriminating the type of gas appliance depending on whether or not the gas appliance is equipped.

[0002]

2. Description of the Related Art In a gas meter, there are two representative methods for detecting the occurrence of gas leakage and shutting off gas, namely, an abnormal gas flow rate inspection function and an instrument continuous use time excess inspection function. The former has a function of driving a gas shut-off valve to shut off a gas flow path when an abnormally large gas flow is detected by a gas flow meter, while the latter uses a gas appliance for an abnormally long time. In this case, similarly, the function is to drive the gas cutoff valve to cut off the gas flow path.

As a conventional gas meter to which such a safety function is added, there is a city gas meter equipped with a microcomputer.
As an abnormal gas flow rate inspection function, there are a case where the gas flow path is cut off when the total maximum flow rate is exceeded, and a case where the gas flow path is cut off when the individual maximum flow rate is exceeded. Specific values of the total maximum flow rate and the individual maximum flow rate differ depending on the number of gas meters.

For example, meter numbers 1, 2, 3, 5, 7
In the city gas meter of, the individual maximum flow rate (m ³ / h)
"1.5", "2.8", "4.8", "5.6",
Each is set to “6.9” and the total maximum flow rate (m ³ / h)
Are “1.8”, “3.7”, “5.4”, “8.
8 "and" 12.2 ".

On the other hand, the duration of a gas meter having a function for inspecting the excessive use of the appliance is classified according to the amount of heat, and the calorific value classification (Kcal / h) is -500, -5.
Less than 000, less than -6000, less than -7000, -90
In the categories of less than 00, less than -12000, and less than -14000, the durations (minutes) are "unlimited" and "7
20 "," 720 "," 720 "," 390 "," 39 "
0 "and" 120 ".

[0006]

However, the gas meters having the above-mentioned safety functions have the following problems. That is, in the case of a gas meter having an abnormal gas flow rate inspection function, if a very small amount of gas flows as a gas leak state, it cannot be detected. Therefore, there is a problem that the gas continues to flow without being shut off, resulting in a gas accident. Conversely, when a gas appliance using a high-calorie gas is used for a long time, there is a problem that this is determined to be a gas leak and a malfunction is caused.

[0007] On the other hand, in the case of a gas meter having an equipment continuous use time excess inspection function, a gas leak accident can be prevented beforehand by changing the continuous time according to the gas use amount, but the gas use amount is large. The use time is not as short as the appliance. Therefore, there is a problem that a malfunction is likely to occur.

In the gas meter having the safety function of the abnormal gas flow rate inspection function and the instrument continuous use time excess inspection function as described above, in order to prevent the malfunction of the gas leak detection, the gas instrument used on the gas meter side is required. It is indispensable to determine the type of the information. However,
In a conventional gas meter, there is no method for effectively discriminating the type of the used gas appliance.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to easily determine a gas appliance by detecting the presence or absence of a gas governor, thereby preventing erroneous operation of safety functions. Another object of the present invention is to provide a used gas appliance discriminating apparatus that enables early detection of gas leakage.

[0010]

According to a first aspect of the present invention, in a gas supply system for supplying gas to a gas appliance via a gas meter having a gas shutoff function, the gas supply pressure in the gas meter is determined. A pressure fluctuation means for actively fluctuating, a gas pressure detection means for detecting a gas supply pressure after a gas flow rate is stabilized before and after the pressure fluctuation means is operated, and before and after the pressure fluctuation means is operated. Gas flow rate detecting means for detecting a gas flow rate in each of the following, a first calculated value obtained from the gas supply pressure and the gas flow rate before fluctuating by the pressure fluctuating means, and Calculating means for calculating each of the second calculated values obtained from the gas supply pressure and the gas flow rate; and a first calculating means calculated by the calculating means. Comparing the calculated value with the second calculated value to determine whether the gas appliance is equipped with a gas governor, and determining the type of the gas appliance based on the result. .

In the used gas appliance discriminating apparatus, the gas supply pressure and the gas flow rate are detected after the gas flow rate in the gas meter is stabilized and before the pressure varying means operates. Thereafter, when the gas supply pressure is actively fluctuated by the pressure fluctuation means, the gas flow rate is stabilized, and then the gas supply pressure and the gas flow rate are detected again. Subsequently, a first calculation value obtained from the gas supply pressure and the gas flow rate before the fluctuation by the pressure fluctuation means, and a second calculation value obtained from the gas supply pressure and the gas flow rate after the fluctuation by the pressure fluctuation means.
Are respectively calculated. Thereafter, the determining means compares the first calculated value and the second calculated value calculated by the calculating means, and determines whether or not the gas appliance is equipped with a gas governor based on a result of the comparison. Based on the result, the type of the gas appliance is determined.

According to a second aspect of the present invention, there is provided a discriminating apparatus for a gas appliance to be used, wherein the calculating means of the first discriminating device determines each of the first calculated value and the second calculated value with respect to the square root of the gas supply pressure. Is calculated by subtracting the value from the gas flow rate. When the first calculation value is equal to the second calculation value, the gas appliance is equipped with a gas governor. Is determined, and when the first calculated value is different from the second calculated value, it is determined that the gas appliance is not equipped with the gas governor.

Here, the principle of discriminating the used gas appliance according to the present invention will be described.

In general, in a gas meter, when the gas supply pressure is actively changed, when the gas governor (pressure regulator) is provided in the gas appliance to be used (for example, a gas grill), the fluctuation of the gas supply pressure is reduced. Since the gas governor absorbs, there is no influence on the gas flow rate. On the other hand, when there is nothing obstructing the flow of gas inside the used gas appliance, that is, when a gas governor is not provided (for example, a gas table), there is a theoretical relationship between the square root of the gas supply pressure and the gas flow rate. There is a proportional relationship.

In the present invention, attention is paid to this proportional relationship, and the calculated value calculated from the gas supply pressure and the gas flow rate before and after the fluctuation is compared. When the two values are equal, the proportional relationship is maintained. Therefore, in this case, it is determined that the gas governor is provided, and if they are different, it is determined that the gas governor is not provided.
And depending on the presence or absence of this gas governor, the gas appliance used,
For example, it is possible to determine whether it is a gas grill or a gas table.

In the present invention, the presence or absence of the gas governor can be detected not only when the gas appliance is used (at the time of ignition) but also when the use is stopped (at the time of fire extinguishing).

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a gas supply system 1 according to one embodiment of the present invention. The gas supply system 1 connects a gas meter 10 and a gas appliance 20 including, for example, a gas grill (equipped with a gas governor) or a gas table (not equipped with a gas governor) via a pipe 17 to supply gas a. The pipe 17 is provided with a gas stopper 17a as opening / closing means.

A gas pipe 11 serving as a gas flow path is provided inside the gas meter 10. The gas pipe 11 has a pressure fluctuation device 12 as gas pressure fluctuation means, a gas shutoff valve 13 for shutting off a gas flow path in an abnormal condition, and a gas pressure sensor 14 for detecting pressure fluctuation by the pressure fluctuation device 12. Flow meter 1 for measuring the gas flow rate
5 are sequentially arranged.

The pressure fluctuation device 12 may be any device that can actively generate pressure fluctuation, and for example, a proportional valve is used. According to this proportional valve, it is possible to suppress the pressure fluctuation on the upstream side of the gas meter 10 and actively generate the pressure fluctuation.

FIG. 2 shows the configuration of the control unit 16 in the gas supply system 1 of the present embodiment. This control unit 1
6 has a CPU (central processing unit) 30. CPU
30 is a ROM (read only memory) via a bus
31, a RAM (random access memory) 32 and the like. The ROM 31 stores a control program as shown in a flowchart (FIG. 3) described later. The CPU 30 uses the RAM 32 as a working area and executes a program stored in the ROM 31 to determine whether the gas appliance 31 is equipped with a gas governor and to determine the type.

The I / O (input / output) port 33 is connected to a C
An interface for sending a drive signal from the PU 30 to the pressure fluctuation device 12 and sending each output signal of the pressure fluctuation device 12, the gas pressure sensor 14, and the gas flow meter 15 to the CPU 30.

The CPU 30 sends a drive signal to the pressure fluctuation device 12 to actively fluctuate the supply pressure of the gas a flowing through the gas meter 10. In this pressure change, for example an initial pressure and H _1, as further pressure of H ₂ after fluctuation [Delta] H is increased the pressure becomes H ₁ + [Delta] H, and increases the supply pressure stepwise.

After detecting the ignition of the gas appliance 20 and confirming the stable state of the gas flow rate, the CPU 30 obtains the gas supply pressure H _i1 and the gas flow rate Q _i1 before the pressure fluctuates according to Equation 1. In addition to calculating the value (first calculated value), the calculating means may also be used as calculating means for calculating (second calculated value) obtained from Equation 2 from the changed gas supply pressure _Hi2 and gas flow rate _Qi2. Function.

[0025]

[Equation 1] Q _i1 −A√H _i1 (A: constant)

[0026]

[Equation 2] Q _i2 −A√H _i2 (A: constant)

The CPU 30 further compares the calculated first calculated value with the second calculated value, determines whether or not the gas appliance 20 is equipped with a gas governor based on a result of the comparison. It also functions as a determination unit for determining the type of the appliance 20.

The CPU 30 also has an abnormal gas flow rate inspection function or an instrument continuous use time excess inspection function as described above, and determines whether or not the gas flow path should be shut off by these safety functions according to the type of the gas appliance 20. When it is determined that the valve should be shut off, a valve shutoff signal is output. I
The / O (input / output) port 34 is an interface for sending the valve shutoff signal to the drive circuit 35. CPU 30
The drive circuit 35 that has received the valve shut-off signal sent from the controller closes the gas shut-off valve 13 and shuts off the gas flow path 11.

Next, the operation of the gas supply system 1 of this embodiment will be described with reference to the flowchart shown in FIG.

The CPU 30 first sets the i-th gas appliance 2
0 is detected (step S300), and after confirming whether the gas flow rate is stable (step S30).
1; Y), the output of the gas pressure sensor 14 and the output of the gas flow meter 15 are received, and the gas supply pressure H _i1 and the gas flow rate Q _i1 before fluctuation are obtained (step S302).

Next, the CPU 30 sends a drive signal to the pressure fluctuation device 12 to actively change the gas supply pressure flowing through the gas meter 10, for example, in a step-like manner (step S300). Then, after confirming whether or not the gas flow rate is stable (Step S304; Y), the changed gas supply pressure _Hi2 and the gas flow rate _Qi2 are obtained (Step S305). Next, the first operation value (Q _i1 -A√)
H _i1 ) and the second operation value (Q _i2 −A√H _i2 ) to determine whether or not both are equal (step S30).
6).

If it is determined that the first calculated value is equal to the second calculated value (Y), the CPU 30 obtains a constant value Qg represented by the following equation (step S307). That is,
In this case, the pressure fluctuation is absorbed and the gas flow rate is stabilized, whereby the CPU 30 determines that the gas governor is installed in the ignited i-th gas appliance 20.

[0033]

[Equation 3] Qg = Q _i2 −A√H _i2

If the first calculated value is not equal to the second calculated value (step S306; N), the CPU 30 obtains a constant A by the following equation and replaces it with the original value (step S308).

[0035]

A = {Q _i2 −Qg} / A√H _i2

That is, in this case, the pressure fluctuation has not been absorbed, and the CPU 30 determines that the gas governor is not installed in the i-th gas appliance 20, and determines for the next gas appliance. The constant A is rewritten to the newly obtained value, and “i” is rewritten to “i + 1” (step S309), and the process returns to step 300. Thereafter, it is determined whether or not the next gas appliance is equipped with a gas governor in the same manner as described above.

As described above, when it is determined whether the gas appliance 20 is equipped with the gas governor, the type of the gas appliance 20 is determined based on the result, and in this embodiment, whether the gas appliance 20 is the gas grill or the gas table is determined. It can be carried out.

After the type of the gas appliance 20 has been determined,
The CPU 30 further receives the result of the determination, and determines whether or not to interrupt the gas flow path by using the abnormal gas flow rate inspection function or the tool continuous use time excess inspection function. here,
If it is determined that the gas appliance 20 is equipped with a gas governor, that is, if the gas appliance 20 is a gas grill, there is clearly no possibility of gas leakage. On the other hand, when it is determined that the gas appliance 20 is not equipped with the gas governor, that is, when the gas appliance 20 is a gas table, there is a possibility of gas leakage.

As described above, in this embodiment, the type of the gas appliance 20 can be easily determined, and the possibility of gas leakage can be determined in accordance with the type. Leaks can be detected early.

After the type of the gas appliance 20 has been determined, it is necessary to determine whether or not gas has leaked by the above-described abnormal gas flow rate inspection function or the appliance continuous use time excess inspection function, and to shut off the gas flow path. Gas shut-off valve 1 when judged
The operation of closing 3 is the same as the conventional operation.

The present invention has been described with reference to the embodiments.
The present invention is not limited to the above embodiments, and can be variously modified without changing the gist of the invention. For example, in the above embodiment, the case where the use of the gas appliance 20 is started (at the time of ignition) has been described.
It can also be applied when the use of the equipment is stopped (when the fire is extinguished). In this case, in step S300 in FIG. 3, “detection of ignition of appliance” becomes “detection of extinguishing of appliance”, and in step S309, “i = i + 1” is changed to “i = i−”.
Except for "1", it is the same as the above embodiment, and the description is omitted.

[0042]

As described above, according to the gas appliance discriminating apparatus according to the first and second aspects, the pressure fluctuation is actively generated, and before and after the pressure fluctuation,
A predetermined calculation value is obtained from the gas flow rate and the gas supply pressure, and it is determined whether or not the gas governor is equipped in the gas appliance to be used by comparing these calculation values. Gas leaks can be detected early, and gas accidents can be prevented beforehand.
The effect of improving safety is achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a gas supply system according to an embodiment of the present invention in a partial cross section.

FIG. 2 is a block diagram illustrating a configuration of a control unit in the used gas appliance discriminating apparatus according to one embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of the used gas appliance discriminating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas supply system 10 Gas meter 12 Pressure fluctuation device 13 Gas shutoff valve 14 Gas pressure sensor 16 Control part

Continuation of the front page (56) References JP-A-5-215586 (JP, A) JP-A-5-166084 (JP, A) JP-A-5-215585 (JP, A) JP-A-1-116414 (JP) , A) JP-A-3-236513 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01F 3/22

Claims (2)

(57) [Claims] 1. A gas supply system for supplying gas to a gas appliance via a gas meter having a gas shut-off function, comprising: a pressure fluctuation means for actively fluctuating a gas supply pressure in the gas meter; Gas pressure detecting means for detecting the gas supply pressure after the gas flow rate is stabilized before and after, and gas flow rate detecting means for detecting the gas flow rate before and after the pressure fluctuation means operates, respectively. A first calculated value obtained from the gas supply pressure and the gas flow rate before the fluctuation by the pressure fluctuation means, and a second calculation value obtained from the gas supply pressure and the gas flow rate after the fluctuation by the pressure fluctuation means are calculated. Calculating means for calculating each of them; comparing the first calculated value and the second calculated value calculated by the calculating means, Bana it is determined whether it is equipped, as a result the use gas appliance discriminating apparatus characterized by comprising a discrimination means for discriminating the type of the gas appliance. 2. The method according to claim 1, wherein the calculating means obtains a value obtained by multiplying each of the first calculated value and the second calculated value by a predetermined constant with respect to a square root of the gas supply pressure, and subtracts the value from the gas flow rate. The determination means determines that the gas appliance is equipped with a gas governor when the first calculated value is equal to the second calculated value, and determines the first calculated value and the second calculated value. The apparatus according to claim 1, wherein it is determined that the gas appliance is not equipped with a gas governor when the gas appliance is different.