JP2005172498A - Gas cutoff system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent abnormal measurement of a gas meter or abnormal gas burning in a gas appliance, when a GHP and the like are provided at the upstream of the piping of the gas cutoff system, and when the gas pressure supplied to a gas cutoff system is largely fluctuating. <P>SOLUTION: By a flow fluctuation determination means 8a for determination of flow fluctuation, the existence of the fluctuation is determined if the amount of the flow measured by a flow measurement means 14 exceeds the prescribed number of times n, and prescribed fluctuation range m per unit time t, and if the fluctuation of the flow is existing, by a pressure pulsation determination means 8b for determinating pressure pulsation by operating a pressure sensor 9 for a certain time continuously, the accurate pressure pulsation value is obtained. Consequently, the abnormal measurement or the abnormal gas burning in the gas appliance is prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas shut-off device that measures a gas flow rate and shuts off a gas passage when an abnormal flow rate is measured to ensure safety in using the gas.

Conventionally, this type of gas shut-off device (gas accident prevention device) has a function of shutting off gas when deviating from an appropriate gas use condition stored in advance (see, for example, Patent Document 1).
FIG. 4 shows a conventional gas accident prevention apparatus described in the publication. In FIG. 4, the gas passes through the meter cock 2 of the gas supply line 1 and enters the gas meter 4 through the shut-off device 3.

The gas is supplied to the house after the flow rate is integrated by the gas meter 4. Reference numeral 5 denotes a flow rate measuring device, for example, which obtains a mechanical signal from the gas meter 4 and continuously sends a flow rate signal to the control device 6 every moment. The control device 6 compares the current gas flow rate value with a limit value determined to be appropriate as a gas usage method stored in the control device 6 in advance, and determines that it is abnormal if it deviates from this use condition. If it is determined that there is an abnormality, a cutoff signal is sent to the cutoff device 3 so as to cut off the supply of gas. 7 is a power source for these devices. In addition, an embodiment in which each of these devices is integrated with the gas meter 4 is also described. This apparatus is generally called a gas microcomputer meter, and is installed in most households in recent years, and has a great effect on reducing gas accidents.
Japanese Patent No. 1597815 (page 3-5, FIGS. 1-3)

  However, in the conventional gas shut-off device, when there is a GHP or the like on the upstream side of the pipe of the gas shut-off device and the pressure supplied to the gas shut-off device fluctuates greatly, the flow rate of the measurement fluid fluctuates, so accurate measurement can be obtained. There is a problem that the gas combustion equipment such as the gas stove and the gas water heater cannot generate abnormal combustion.

  An object of the present invention is to solve the above-described conventional problems and to cut off the supply of gas when the pressure pulsation value fluctuates excessively.

  In order to solve the above-described conventional problems, in the gas cutoff device of the present invention, the measured flow rate fluctuates beyond a predetermined number of times n and a predetermined fluctuation range m during a predetermined unit time t. If the pressure pulsation value is large, it is determined by the pressure pulsation large detection means, and the gas shutoff valve is determined. It is closed and the supply of gas is stopped.

  As a result, when the pressure pulsation value fluctuates excessively, it is possible to stop the gas supply, so that an accurate flow rate measurement value cannot be obtained, or gas combustion equipment such as a gas stove or gas water heater is abnormally combusted. Can be prevented in advance.

  In the gas shut-off device of the present invention, when the pressure pulsation value fluctuates excessively, the gas supply can be stopped. Therefore, when an accurate flow rate measurement value cannot be obtained, or when a gas such as a gas stove or a gas water heater is used. It is possible to prevent the combustion device from generating abnormal combustion.

  According to a first aspect of the present invention, there is provided a flow path for flowing a gas, a flow rate detecting means for measuring a flow rate of the gas flowing through the flow path, a flow rate detecting means driving circuit for driving the flow rate detecting means, A shut-off valve that shuts off the flow path, a shut-off valve drive circuit for operating the shut-off valve, a pressure sensor that periodically detects the pressure of the gas, a pressure sensor drive circuit that drives the pressure sensor, When the pressure sensor, the shutoff valve, and the flow rate detecting means are controlled, and the measured flow rate fluctuates beyond a predetermined number of times n and a predetermined fluctuation range m during a predetermined unit time t, A flow rate variation determining unit that determines that there is a fluctuation, and a control that includes a pressure pulsation determining unit that continuously operates the pressure sensor for a predetermined time to determine a pressure pulsation value when the flow rate variation determining unit determines that there is a flow rate variation. circuit , By providing a battery as a power source, it is possible to obtain exactly the pressure pulsation value. In addition, since the current consumption of the pressure sensor is very large, it was impossible to continuously drive the gas shut-off device using a battery as the main power source. Thus, the pressure pulsation value can be detected with low current consumption, and can be mounted on the gas cutoff device.

  In the second invention, in particular, the pressure pulsation value measured by the pressure sensor of the first invention fluctuates beyond a predetermined number of times N and a predetermined fluctuation range M during a predetermined unit time T. In this case, an abnormally excessive pressure pulsation value can be accurately determined by providing the pressure pulsation large detection means for determining that the pressure pulsation is large.

  According to a third aspect of the present invention, there is provided a gas pulsation large-time gas shut-off means for driving a shut-off valve, closing a flow path and shutting off a gas when the pressure pulsation is determined to be large by the pressure pulsation large detecting means of the second invention. By providing, when the pressure pulsation value fluctuates excessively, not only accurate flow rate measurement values can not be obtained, but also gas combustion equipment such as gas stoves and gas water heaters cause problems such as more combustion The gas supply can be stopped.

  In the fourth aspect of the invention, the flow rate detecting means for detecting the gas flow rate of the third aspect of the invention is an ultrasonic type.

  In the fifth aspect of the invention, the flow rate detecting means for detecting the gas flow rate of the third aspect of the invention is a flow sensor type.

  In the sixth aspect of the invention, the flow rate detecting means for detecting the gas flow rate of the third aspect of the invention is a fluidic type.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 shows a configuration diagram of a gas shut-off device according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 8 denotes a control circuit, which includes a flow rate fluctuation determination means 8a, a pressure pulsation determination means 8b, a pressure pulsation large detection means 8c, and a pressure pulsation large gas cutoff means 8d. Reference numeral 9 denotes a pressure sensor, which is normally intermittently driven by the pressure sensor driving circuit 10 to detect pressure. Reference numeral 11 denotes a shut-off valve, which is driven by a shut-off valve drive circuit 12 and closes the flow path 13 to stop the gas supply. Reference numeral 14 denotes a flow rate detection means, which is driven by a flow rate detection means drive circuit 15 and transmits a flow rate value to the control circuit 8. Reference numeral 16 denotes a battery as a power source for driving them.

  The operation and action of the gas shut-off device configured as described above will be described below.

  FIG. 2 is a diagram showing fluctuations in the flow rate value detected by the flow rate detection means. When there is a device for generating pressure pulsation such as GHP on the upstream side of the gas shutoff device, the flow rate value fluctuates greatly, and a predetermined unit time. It fluctuates beyond a predetermined number of times n and a predetermined fluctuation range m during t. In this case, the pressure sensor is continuously driven on the assumption that the flow rate varies.

  Next, FIG. 3 is a diagram showing the pressure value detected by the pressure fluctuation determination means, and fluctuates beyond a predetermined number of times N and a predetermined fluctuation range M during a predetermined unit time T. In this case, the pressure pulsation large detection means determines that the pressure pulsation is large. If it is determined that the pressure pulsation is large, the shutoff valve is driven to stop the gas supply, thereby ensuring safety.

  As described above, in the embodiment of the present invention, the flow path for flowing the gas, the flow rate detecting means for measuring the flow rate of the gas flowing through the flow path, and the flow rate detecting means driving circuit for driving the flow rate detecting means, A shut-off valve for shutting off the gas passage in the event of an abnormality, a shut-off valve drive circuit for operating the shut-off valve, a pressure sensor for periodically detecting the gas pressure, and a pressure sensor drive for driving the pressure sensor When the circuit, the pressure sensor, the shut-off valve, and the flow rate detecting means are controlled and the measured flow rate fluctuates beyond a predetermined number of times n and a predetermined fluctuation range m during a predetermined unit time t. A flow fluctuation determining means for determining that there is a flow fluctuation; and a pressure pulsation determining means for continuously operating the pressure sensor for a predetermined time and determining a pressure pulsation value when the flow fluctuation determining means determines that there is a flow fluctuation. And e were control circuit, by providing a battery for supplying a current to the shut-off valve and the flow rate detecting means and the control circuit and the pressure sensor, it becomes possible to accurately obtain the pressure pulsation value. In addition, since the current consumption of the pressure sensor is very large, it was impossible to continuously drive the gas shut-off device using a battery as the main power source. Thus, the pressure pulsation value can be detected with low current consumption, and can be mounted on the gas cutoff device.

  Further, when the pressure pulsation value measured by the pressure sensor fluctuates beyond a predetermined number of times N and a predetermined fluctuation range M during a predetermined unit time T, the pressure determined as a large pressure pulsation By providing the pulsation large detection means, an abnormally excessive pressure pulsation value can be accurately determined.

  Further, when the pressure pulsation large detection means determines that the pressure pulsation is large, the pressure pulsation value is excessively increased by driving the shut-off valve and closing the flow path to shut off the gas. If it fluctuates, it will not be possible to obtain an accurate flow rate measurement value, but gas combustion equipment such as gas stoves and gas water heaters may cause more combustion, so the gas supply can be stopped. It becomes.

  As described above, the gas shut-off device according to the present invention includes the pressure pulsation large-time gas shut-off means that drives the shut-off valve to close the flow path and shut off the gas when the pressure pulsation is determined to be large. When the pressure pulsation value fluctuates excessively, not only accurate flow rate measurement values cannot be obtained, but also gas combustion equipment such as gas stoves and gas water heaters may cause more combustion, so gas supply Therefore, it can be adapted for use in household and industrial gas meters.

The block diagram which shows the gas interruption | blocking apparatus in Embodiment 1 of this invention Explanatory drawing of the flow volume fluctuation value in Embodiment 1 of this invention Explanatory drawing of the pressure fluctuation value in Embodiment 1 of this invention Configuration diagram showing a conventional gas shut-off device

Explanation of symbols

8a Flow rate variation judging means 8b Pressure variation judging means 8c Pressure fluctuation large detecting means 8d Gas pressure large shutoff means 9 Pressure sensor 10 Pressure sensor drive circuit 11 Shutoff valve 12 Shutoff valve drive circuit 13 Flow path 14 Flow rate detecting means 15 Flow rate detection Means drive circuit 16 Battery

Claims (6)

A flow path for flowing a gas, a flow rate detecting means for measuring a flow rate of the gas flowing through the flow path, a flow rate detecting means driving circuit for driving the flow rate detecting means, and a blocking for blocking the flow path in the event of an abnormality A valve, a shut-off valve drive circuit for operating the shut-off valve, a pressure sensor that periodically and periodically detects a gas pressure, a pressure sensor drive circuit that drives the pressure sensor, and the pressure sensor and the shut-off valve If the measured flow rate fluctuates beyond a predetermined number of times n and a predetermined fluctuation range m during a predetermined unit time t, a flow rate that determines that there is a flow rate fluctuation. A control circuit having a pressure pulsation determining means for continuously operating the pressure sensor for a predetermined time and determining a pressure pulsation value when the flow rate determining means and the flow rate fluctuation determining means determine that there is a flow fluctuation; Gas cutoff apparatus provided with a battery. Pressure pulsation large detection for determining that the pressure pulsation is large when the pressure pulsation value measured by the pressure sensor fluctuates beyond a predetermined number of times N and a predetermined fluctuation range M during a predetermined unit time T. The gas cutoff device according to claim 1, further comprising means. 3. The gas shut-off device according to claim 2, further comprising a pressure pulsation large gas shut-off means for driving the shut-off valve to close the flow path and shut off the gas when the pressure pulsation large detecting means determines that the pressure pulsation is large. The gas cutoff device according to claim 3, wherein the flow rate detecting means for detecting the gas flow rate is an ultrasonic type. The gas shut-off device according to claim 3, wherein the flow rate detecting means for detecting the gas flow rate is a flow sensor type. The gas shut-off device according to claim 3, wherein the flow rate detecting means for detecting the gas flow rate is a fluidic type.

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