JP6781619B2 - Gas meter - Google Patents

Description

The present invention relates to a gas meter capable of detecting the flow rate of flammable gas and shutting off the supply of flammable gas.

The supplier sends flammable gas to the consumer facility through piping. Then, at the consumer facility, the flow rate of the combustible gas used is detected through the gas meter. The consumer pays the supplier a fee according to the flow rate used.

However, there are some consumers who do not pay the price or delinquent the price even though they use flammable gas. Therefore, there is known a technique for promptly giving a stop notice or a stop instruction of a flammable gas at the time of meter reading according to the unpaid status of the combustible gas charge (for example, Patent Document 1).

Japanese Patent No. 5739846

In the event of unpaid charges based on the use of flammable gas, it is possible to completely cut off the supply of flammable gas and limit the further use of flammable gas by consumers by using the above-mentioned technology. Become. However, regardless of the reason for unpaid charges and regardless of the usage status of the consumer, if the supply of flammable gas is completely cut off, the gas appliances of the consumer facility cannot be used at once. Inconvenience may occur.

In view of such a problem, an object of the present invention is to provide a gas meter capable of realizing a new supply mode of flammable gas.

In order to solve the above problems, the gas meter of the present invention has a flow rate sensor for detecting the flow rate of flammable gas, a motor, and a valve body, and converts the rotation of the motor into a linear movement of the valve body to convert the valve body. It is equipped with a shutoff valve that shuts off the supply of flammable gas by the body and a shutoff control unit that controls the opening of the shutoff valve. The shutoff valve is other than fully open and fully closed by stopping the rotation of the motor in the middle . It achieved middle opening is opening, interruption control unit, as the predetermined operating condition is satisfied, the flow rate of the combustible gas flow rate sensor detects reaches a predetermined target flow rate, the combustible gas from the target flow rate the flow rate is lowered opening of many familiar if shut-off valve, to perform a closed loop control to raise the degree of opening of the shut-off valve if less flow rate of the combustible gas than the target flow rate.

The shutoff control unit may further include a change determination unit that changes the opening degree of the shutoff valve and determines whether or not an arbitrary parameter changes according to the change in the opening degree of the shutoff valve.

According to the present invention, it is possible to realize a new supply mode of flammable gas.

It is a figure which showed the schematic structure of the gas supply system. It is a functional block diagram which showed the schematic structure of a gas meter. It is sectional drawing which showed the schematic structure of the shut-off valve. It is a flowchart which showed an example of the processing of a cutoff control unit. It is a flowchart which showed an example of the processing of a cutoff control unit. It is a flowchart which showed an example of the processing of a cutoff control unit and a change determination unit.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, etc. shown in the embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. To do.

(Gas supply system 100)
FIG. 1 is a diagram showing a schematic configuration of a gas supply system 100. In the gas supply system 100, as shown by the arrow in the figure, the flammable gas is supplied from the combustible gas supplier through the upstream pipe 110, the flow rate of the flammable gas is detected by the gas meter 120, and the downstream of the gas meter 120. Combustible gas is delivered to the gas appliance 140 in the consumer facility 10 through the downstream pipe 130 connected to the side. Hereinafter, the configuration of the gas meter 120 will be described in detail.

(Gas meter 120)
FIG. 2 is a functional block diagram showing a schematic configuration of the gas meter 120. The gas meter 120 includes a shutoff valve 150, a pressure sensor 160, a flow rate sensor 170, a display unit 180, and a calculation unit 190.

The shutoff valve 150 controls the opening degree of the valve and controls the flow rate of the flammable gas flowing through the gas flow path 12.

FIG. 3 is a cross-sectional view showing a schematic configuration of the shutoff valve 150. The shutoff valve 150 includes a motor 152 and a valve body 154. The motor 152 is composed of, for example, a stepping motor, and rotates forward or reverse based on a valve opening or closing shutoff signal. Specifically, when a current flows through the coil of the stator 152a, the rotor 152b composed of magnets rotates, and the drive shaft 152c integrally formed with the rotor 152b also rotates. A screw groove is formed at one end of the drive shaft 152c, which fits with the nut portion 154a of the valve body 154 and functions as a lead screw.

By passing an electric current through the motor 152, the drive shaft 152c rotates, and the rotation is converted into a linear movement of the valve body 154 in the axial direction through the lead screw. Specifically, as shown in FIG. 3A, when the motor 152 is rotated in the normal direction, the valve body 154 is separated from the facing surface 156, and the flammable gas faces the valve body 154 as shown by the white arrows. It passes between the surfaces 156. Further, as shown in FIG. 3B, when the motor 152 is inverted, the valve body 154 comes into contact with the facing surface 156, and the flow of flammable gas is blocked. A solenoid may be used instead of the motor 152 to move the valve body 154 in the axial direction.

Further, the shutoff valve 150 is provided with an elastic member 154b that urges the valve body 154 to the facing surface 156 side to absorb the backlash of the reed screw and the valve body 154 and the facing surface 156. Improves the shield performance of.

In this way, the shutoff valve 150 can be switched between fully open and fully closed depending on the position of the valve body 154. Further, in the present embodiment, by stopping the rotation of the motor 152 in the middle, the opening degree is realized to be an intermediate opening degree other than fully open and fully closed. The midway opening will be described in detail later.

Returning to FIG. 2, the pressure sensor 160 is provided downstream of the shutoff valve 150 and detects the pressure of the flammable gas.

The flow rate sensor 170 includes an ultrasonic vibrator 172, an ultrasonic vibrator 174, and a propagation speed derivation unit 176. The ultrasonic vibrators 172 and 174 are arranged at predetermined positions on the upstream side surface and the downstream side surface of the gas flow path 12 downstream of the shutoff valve 150 and upstream of the pressure sensor 160, for example, with sound waves of 20 kHz or higher. It functions as a transmitter and receiver of certain ultrasonic waves. The propagation speed derivation unit 176 detects the propagation time of the ultrasonic waves propagating between the ultrasonic vibrators 172 and 174 via the flammable gas, and derives the flow rate of the flammable gas based on the propagation time.

The display unit 180 is composed of a liquid crystal display, an organic EL (Electro Luminescence) display, and the like, and is used to notify an integrated value of the supply amount (usage amount) of the flammable gas and an abnormality such as leakage of the flammable gas. ..

The arithmetic unit 190 manages and controls the entire gas meter 120 by a semiconductor integrated circuit including a central processing unit (CPU), a PROM in which a program or the like is stored, a RAM as a work area, and the like. Further, the calculation unit 190 functions as a cutoff control unit 192 and a change determination unit 194 in cooperation with the program.

The shutoff control unit 192 controls the opening degree of the shutoff valve 150. For example, based on the detection results of either or both of the pressure sensor 160 and the flow sensor 170, for example, the pressure sensor 160 detects an abnormal value of the pressure of the flammable gas, or the flow sensor 170 is flammable for a predetermined period. When it is detected that the sex gas is continuously flowing at a predetermined flow rate or more, a shutoff signal is output to the shutoff valve 150. Then, the shutoff valve 150 switches the opening degree from fully open to fully closed in response to the fully closed shutoff signal, and shuts off the flammable gas.

Further, the shutoff control unit 192 controls so that the opening degree of the shutoff valve 150 becomes the halfway opening degree (so as to maintain the halfway opening degree) when a predetermined operation condition is satisfied. Here, the halfway opening is an opening between fully open and fully closed, and is an arbitrary opening other than fully open or fully closed, and may have a plurality of stages, and the resolution may be improved. , May change linearly (steplessly).

In order to realize such an intermediate opening degree, the cutoff control unit 192 has a table in the PROM. In the table, the flow rate (or opening degree) of the flammable gas and the energization time (current value) flowing through the shutoff valve 150 are associated with each other. The shutoff control unit 192 refers to the table, extracts the energization time associated with the desired flow rate of the flammable gas, and transmits it to the shutoff valve 150 as a shutoff signal. In this way, the shutoff valve 150 can realize an intermediate opening degree through which the flammable gas is allowed to pass while being restricted at a desired flow rate.

Further, the cutoff control unit 192 may control the opening degree by closed loop (feedback) control using the flow rate sensor 170. For example, the cutoff control unit 192 subtracts the flow rate of the flammable gas detected by the flow rate sensor 170 from a predetermined target flow rate, and derives the energization time of the current flowing through the cutoff valve 150 based on the subtracted value. In this way, it is possible to control the opening degree of the shutoff valve 150 so that the flow rate of the flammable gas detected by the flow rate sensor 170 becomes a predetermined target flow rate.

The change determination unit 194 determines whether or not an arbitrary parameter changes according to the change in the opening degree of the shutoff valve 150 when the opening degree of the shutoff valve 150 is changed by the shutoff control unit 192. The change determination unit 194 makes it possible to flexibly correspond the gas meter 120 to various usage forms (applications). Hereinafter, variations of the usage pattern by the cutoff control unit 192 and the change determination unit 194 will be described.

(Unpaid correspondence)
Depending on the consumer, despite the use of flammable gas, the fee may not be paid or the fee may be delinquent. In this way, in the event of unpaid charges based on the use of flammable gas, it is conceivable to completely shut off the supply of flammable gas and limit the further use of flammable gas by consumers. However, regardless of the reason for unpaid charges and regardless of the usage status of the consumer, if the supply of flammable gas is completely cut off, the gas appliance 140 of the consumer facility 10 will be used at once. It becomes unusable, and inconveniences such as the inability to use the gas appliance 140 when it is urgent may occur. Therefore, by setting the opening degree of the shutoff valve 150 to an intermediate opening degree, a new supply mode of flammable gas is realized.

FIG. 4 is a flowchart showing an example of processing by the cutoff control unit 192. First, the cutoff control unit 192 determines whether or not the unpaid fee (operating condition) has occurred by the consumer (S10). As a result, if no unpaid charges have occurred (NO in S10), the shutoff control unit 192 controls the opening degree of the shutoff valve 150 to be fully open (S11), and repeats the process from step S10. ..

If the unpaid charge has occurred (YES in S10), the cutoff control unit 192 determines whether or not a predetermined time (for example, one month) has passed since the unpaid charge occurred (S12). As a result, if the predetermined time has not elapsed (NO in S12), the shutoff control unit 192 controls the opening degree of the shutoff valve 150 to be an intermediate opening degree (S13), and performs the process from step S10. repeat. In this way, by not completely shutting off the supply of flammable gas, the consumer can be penalized by limiting the use of flammable gas while allowing the consumer to use the gas appliance 140 to a minimum. Can be imposed.

Further, when a predetermined time elapses after the unpaid charge occurs (YES in S12), the shutoff control unit 192 controls the opening degree of the shutoff valve 150 to be fully closed (S14), and from step S10. Repeat the process of. In this way, the combustible gas is given to the consumer who continues to be unpaid despite the limited flow rate of the combustible gas, while giving a predetermined time to enable the minimum use of the combustible gas. It is possible to completely cut off the supply of.

(Rate plan)
It is also possible to develop a new plan for the price of flammable gas. For example, the supplier determines a predetermined period (hour, day, month, year) and the total amount (contract amount) that can be used in the predetermined period with the consumer.

FIG. 5 is a flowchart showing an example of processing by the cutoff control unit 192. First, the cutoff control unit 192 determines whether or not the total amount of combustible gas detected by the flow rate sensor 170 exceeds the contracted amount (whether or not the operating conditions are satisfied) (S20). As a result, if the contracted amount is not exceeded (NO in S20), the shutoff control unit 192 controls the opening degree of the shutoff valve 150 to be fully open (S21), and repeats the process from step S20.

If the contracted amount is exceeded (YES in S20), the shutoff control unit 192 controls the opening degree of the shutoff valve 150 to be an intermediate opening degree (S22), and repeats the process from step S20.

With such a configuration, the consumer can use the flammable gas to the maximum up to the contract amount, and if the contract amount is exceeded, the use of the flammable gas is restricted, and the contract is made. It is possible to grasp that the amount has been exceeded.

Further, as another charge plan, instead of setting the basic charge low, a setting may be provided in which the opening degree of the shutoff valve 150 is controlled to be an intermediate opening degree from the beginning. With such a configuration, it is possible to provide a cheap rate plan to a consumer who does not use a water heater that requires a flow rate (although it supplies hot water by electricity) but wants to use only a gas stove or the like that does not require a large flow rate.

(Simple governor)
For example, the gas appliance 140 in the gas supply system 100 is provided with a governor (pressure regulator) that automatically controls the pressure of the flammable gas according to the increase or decrease in the flow rate (consumption amount) of the flammable gas. .. However, even if such a governor is not provided, the governor can be substituted by the cutoff control unit 192.

Specifically, the cutoff control unit 192 controls the opening degree by closed loop (feedback) control using the pressure sensor 160. For example, the shutoff control unit 192 subtracts the pressure of the flammable gas detected by the pressure sensor 160 from the predetermined target pressure based on the operating conditions, and the current flowing through the shutoff valve 150 based on the subtracted value. Derived the energizing time. In this way, it is possible to control the opening degree of the shutoff valve 150 so that the pressure of the flammable gas detected by the pressure sensor 160 becomes a predetermined target pressure.

(Pressure adjustment)
Further, the pressure adjustment by the conduit network can be substituted by controlling the opening degree of the shutoff valve 150 to the intermediate opening degree by the shutoff control unit 192. Conventionally, the pressure of the conduit network was adjusted by using a separate pressure regulator. However, since the pressure of the flammable gas can be adjusted by the halfway opening in each gas meter 120, the pressure regulator is separately used. It is possible to reduce the cost without having to prepare.

(Abnormality detection)
Further, the cutoff control unit 192 and the change determination unit 194 can be used in combination to detect an abnormality in the gas meter 120.

FIG. 6 is a flowchart showing an example of processing of the cutoff control unit 192 and the change determination unit 194. First, the shutoff control unit 192 changes the opening degree of the shutoff valve 150 at a predetermined trigger that becomes an operating condition (S30). Next, the change determination unit 194 determines whether or not an arbitrary parameter, for example, the flow rate detected by the flow rate sensor 170, has changed (following) according to the change in the opening degree of the shutoff valve 150 (S31). ).

As a result, if the flow rate also changes according to the change in the opening degree of the shutoff valve 150 (YES in S31), the change determination unit 194 normally performs the shutoff valve 150, the flow rate sensor 170, and the circuits around the shutoff valve 150. It is determined that the vehicle is being driven (S32), and the processing from step S30 is repeated. Further, if the flow rate does not change following the change in the opening degree of the shutoff valve 150 (NO in S31), the change determination unit 194 is the shutoff valve 150, the flow rate sensor 170, or It is determined that any of the circuits around it is abnormal (S33), and the process from step S30 is repeated.

With such a configuration, it is possible to diagnose with the gas meter 120 itself that the shutoff valve 150, the flow rate sensor 170, and the like are operating normally.

Further, when a governor is provided in, for example, the gas appliance 140 in the gas supply system 100, even if the supply pressure of the flammable gas changes, the pressure is adjusted by the governor, so that the flow rate of the flammable gas does not change. However, if the governor is not functioning properly, the flow rate of the flammable gas will change as the supply pressure of the flammable gas changes.

Therefore, the opening degree of the shutoff valve 150 is changed by the shutoff control unit 192 at a predetermined determination timing which is an operating condition, and the flow rate detected by the change determination unit 194 by the flow rate sensor 170 is the opening degree of the shutoff valve 150. By determining whether or not the change has been made in response to the change, it is possible to determine whether or not the governor is functioning normally.

(Abnormal response)
Further, when an abnormality is detected in the gas meter 120, the shutoff control unit 192 may set the opening degree of the shutoff valve 150 to an intermediate opening degree instead of fully closing it.

For example, when the flow rate sensor 170 detects a flow rate exceeding the rating (when the operating condition is satisfied), the shutoff control unit 192 sets the opening degree of the shutoff valve 150 as an intermediate opening degree. With such a configuration, it is possible for consumers to use the minimum amount of flammable gas while limiting the flow rate and ensuring safety.

In addition, when the conduit is damaged (satisfies the operating conditions) in the event of a disaster such as an earthquake, the flow rate of some consumer facilities 10 with low priority for supplying flammable gas is limited by the halfway opening. However, the combustible gas may be supplied to a hospital or an important facility having a high priority, for example, to supply a sufficient combustible gas. With such a configuration, it is possible to secure the minimum amount of combustible gas used by the consumer and the amount of combustible gas supplied to the facility where the combustible gas should be supplied with high priority.

Similarly, when the conduit is damaged during a disaster such as an earthquake and the supplier cannot supply sufficient flammable gas (satisfies the operating conditions), the shutoff valve 150 of the consumer facility 10 The opening degree may be an intermediate opening degree. Such a configuration limits the operation of the water heater, for example, but allows the consumer to boil water on a gas stove and to cook at a minimum. In this way, hygiene and nutrition can be ensured.

In addition, the shutoff control unit 192 switches the shutoff valve 150 from fully closed to fully open (satisfied the operating conditions) due to the restoration of the conduit after a disaster such as an earthquake, after the construction of the conduit, or after the analysis of the conduit network. Even in this case, it is possible to restart the supply of the flammable gas step by step while ensuring safety by passing through the opening in the middle of the period.

Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the claims, which naturally belong to the technical scope of the present invention. Understood.

For example, in the above-described embodiment, a one-step opening other than fully open or fully closed is shown as the halfway opening, but the present invention is not limited to this case, and a plurality of steps may be provided, and the plurality of steps may be sequentially set. May be changed.

Further, in the above-described embodiment, the calculation unit 190 functions as the cutoff control unit 192 and the change determination unit 194 in cooperation with the program, but it is not always provided in the gas meter 120. The operation of the present embodiment may be realized by providing it in an external device and communicating with the gas meter 120.

It should be noted that each step in the processing by the blocking control unit 192 and the change determination unit 194 of the present specification does not necessarily have to be processed in chronological order in the order described in the flowchart, and may include processing in parallel or by a subroutine. Good.

The present invention can be used for a gas meter capable of detecting the flow rate of flammable gas and shutting off the supply of flammable gas.

120 Gas meter 150 Shutoff valve 170 Flow sensor 192 Shutdown control unit 194 Change judgment unit

Claims (2)

A flow sensor that detects the flow rate of flammable gas and
A shutoff valve having a motor and a valve body, converting the rotation of the motor into linear movement of the valve body, and shutting off the supply of the flammable gas by the valve body .
A shutoff control unit that controls the opening degree of the shutoff valve,
With
By stopping the rotation of the motor in the middle, the shutoff valve realizes a halfway opening which is an opening other than fully open and fully closed.
When the cutoff control unit satisfies a predetermined operation condition, the flow rate of the combustible gas becomes larger than the target flow rate so that the flow rate of the combustible gas detected by the flow rate sensor becomes a predetermined target flow rate. A gas meter that executes closed loop control that lowers the opening degree of the shutoff valve and raises the opening degree of the shutoff valve when the flow rate of the flammable gas becomes smaller than the target flow rate . The shutoff control unit changes the opening degree of the shutoff valve.
The gas meter according to claim 1, further comprising a change determination unit for determining whether or not an arbitrary parameter changes according to a change in the opening degree of the shutoff valve.

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