JPH04250319A - Fluidic gas meter equipped with micro flow sensor - Google Patents

Abstract

PURPOSE:To prevent abnormal integration so as to secure safety by mounting checking circuits in a gas flow detecting portion, a flow computing device and a battery, and closing a gas emergency trip valve in the event of abnormalities. CONSTITUTION:Flow signals from a micro flow sensor 4 and a fluidic element 5 are input to a flow computing device 6 and the result of computation by the device 6 is indicated on an indicating portion 8. Within the range where flow signals are input from both the sensor 4 and the element 5, a gas emergency trip valve 2 located inside a gas passage 1 is closed if there is a difference more than a predetermined level between values computed from both signals. The emergency trip valve 2 is closed when a checking circuit 11 mounted in the device 6 detects an abnormality and also when a voltage checking circuit 13 detects a voltage drop below a fixed value. It is thus made possible to immediately shut off gas in the event of abnormalities.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a fluidic gas meter with a microflow sensor that detects the flow rate in a small flow rate range with a microflow sensor and uses a fluidic element to detect the flow rate in a higher flow rate range. It is something.

0002

2. Description of the Related Art In the case of a fluidic gas meter with a microflow sensor, measurements in a small flow rate range that is difficult to accurately measure with a fluidic element are performed using an electronic microflow sensor. In addition, the values detected by the micro flow sensor and fluidic element are processed by the flow rate calculation device (
The flow rate is calculated using the CPU.

[0003] In addition, all power sources in gas meters rely on batteries.

[Problems to be Solved by the Invention] Although the fluidic gas meter with a micro flow sensor employs the above configuration and method, if an error occurs in the output of the micro flow sensor or fluidic element, it is necessary to If you continue to use the product without properly recovering it,
Not only will an error occur in the integrated value, for example, in the case of a so-called microcomputer gas meter that monitors abnormalities based on the flow rate detected by a microflow sensor and a fluidic element, it may not function properly.

[0004] This also applies to failures of arithmetic devices.

[0005] Furthermore, since the gas meter including the microflow sensor is powered by a battery, if the battery voltage drops, this can be a major cause of malfunction, and in this case, the gas meter may not function properly. It disappears.

[0006] An object of the present invention is to provide a fluidic gas meter with a microflow sensor that is configured to immediately stop the gas supply to prevent problems if an abnormality occurs in the microflow sensor, fluidic element, flow rate calculation device, or battery. It is to provide.

[0007]

[Means for Solving the Problems] The structure of the present invention is as follows.

1. A gas meter uses a micro flow sensor to detect the flow rate in a small flow rate range, and a fluidic element to detect the flow rate in a higher flow rate range.
Compare the flow rate signals from both the micro flow sensor and the fluidic element in a certain flow range in which they operate, and if a difference in the flow rate signals exceeds a certain range, the gas installed in the gas flow path A fluidic gas meter with a microflow sensor that incorporates a sensor abnormality check circuit that outputs a shutoff signal to the shutoff valve.

[0009]2. A gas meter uses a micro flow sensor to detect the flow rate in a small flow rate range, and a fluidic element to detect the flow rate in a higher flow rate range.
A calculation device check circuit is provided to diagnose abnormality or failure of the calculation device that calculates the gas flow rate based on the flow rate signal detected by the micro flow sensor or fluidic element, and when this check circuit determines that there is an abnormality or failure, A fluidic gas meter with a microflow sensor configured to output a shutoff signal to a gas shutoff valve installed in a gas flow path.

3. A gas meter uses a micro flow sensor to detect the flow rate in a small flow rate range, and a fluidic element to detect the flow rate in a higher flow rate range.
A voltage check circuit is built into the power supply circuit, and when this voltage check circuit detects a voltage below a certain voltage, it is configured to output a cutoff signal to a gas cutoff valve installed in the gas flow path. Fluidic gas meter with micro flow sensor.

[0011]

[Operation] The flow rate signals from the micro flow sensor and the fluidic element are input to the flow rate calculation device, where the flow rate calculation is performed and displayed on, for example, a display section.

In this operation, within a certain range where flow rate signals from both the microflow sensor and the fluidic element are input, the flow rate is calculated based on both flow rate signals, and if the difference in the calculated values exceeds a certain level, the flow rate is calculated based on both flow rate signals. If this occurs, the gas cutoff valve in the gas flow path is closed.

Similarly, since the flow rate calculation device is equipped with a check circuit using, for example, a watchdog timer system, if this check circuit determines that there is an abnormality, the gas cutoff valve is closed.

Furthermore, the battery voltage is monitored by a voltage check circuit, and the gas cutoff valve is also closed when this voltage drops below a certain value.

[0015]

[Embodiment] In FIG. 1, 1 is a gas flow path, 2 is a gas cutoff valve attached to this gas flow path 1, and 3 is a gas flow rate detection unit, which is composed of a microflow sensor 4 and a fluidic element 5. .

Reference numeral 6 denotes a flow rate calculation unit (CPU), and this flow rate calculation unit 6 includes a calculation circuit 7 that calculates the flow rate based on the flow rate signal from the gas flow rate detection unit 3 and displays it on the display unit 8; The flow rate signals of the micro flow sensor 4 and the fluidic element 5 output from the gas flow rate detection unit 3 are compared in a certain flow rate range, and if there is a difference of more than a certain value between these values, a signal is sent via the cutoff command circuit 10. The gas cutoff valve 2
A sensor abnormality check circuit 9 is incorporated which outputs a signal to shut down the sensor.

Reference numeral 11 designates a calculation device check circuit for checking an abnormality in the flow rate calculation device 7, and when an abnormality is detected in this circuit 11, a signal to shut off is sent to the gas cutoff valve 2 via a shutdown command circuit 12. Output.

Reference numeral 13 designates a voltage check circuit for checking the voltage of a battery 14 that provides power for the entire gas meter, and when this voltage check circuit 13 detects a voltage below a certain level, it shuts off the gas cutoff valve 2. Outputs the signal.

[0019]

[Effects of the Invention] As described above, the present invention immediately closes the gas cutoff valve when an abnormality occurs in the gas flow rate detection sensor, flow rate calculation device, or battery voltage. There is no need to worry about this happening, and it is effective as a safety measure.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the present invention.

[Explanation of symbols]

1 Gas flow path 2 Gas cutoff valve 3 Gas flow rate detection part 4 Micro flow sensor 5 Fluidic element 6 Flow rate calculation device 7 Arithmetic circuit 8 Display section 9 Sensor abnormality check circuit 10　Shutoff command circuit 11 Arithmetic unit check circuit 12 Cutoff command circuit 13 Voltage check circuit 14 Battery

Claims (3)

[Claims] [Claim 1] In a gas meter that detects the flow rate in a small flow rate range using a micro flow sensor and detects the flow rate in a higher flow rate range using a fluidic element,
Compare the flow rate signals from both the micro flow sensor and the fluidic element in a certain flow range in which they operate, and if a difference in the flow rate signals exceeds a certain range, the gas installed in the gas flow path A fluidic gas meter with a microflow sensor that incorporates a sensor abnormality check circuit that outputs a shutoff signal to the shutoff valve. [Claim 2] In a gas meter that detects the flow rate in a small flow rate range using a micro flow sensor and detects the flow rate in a higher flow rate range using a fluidic element,
A calculation device check circuit is provided to diagnose abnormality or failure of the calculation device that calculates the gas flow rate based on the flow rate signal detected by the micro flow sensor or fluidic element, and when this check circuit determines that there is an abnormality or failure, A fluidic gas meter with a microflow sensor configured to output a shutoff signal to a gas shutoff valve installed in a gas flow path. [Claim 3] In a gas meter that detects the flow rate in a small flow rate range using a micro flow sensor and detects the flow rate in a higher flow rate range using a fluidic element,
A voltage check circuit is built into the power supply circuit, and when this voltage check circuit detects a voltage below a certain voltage, it is configured to output a cutoff signal to a gas cutoff valve installed in the gas flow path. Fluidic gas meter with micro flow sensor.