JPH0226511B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fluid control device that prevents gas explosion accidents caused by abnormal outflow of raw gas such as city gas or propane gas.

Conventional configuration and problems Conventionally, the gas meter body has a flow rate sensor that detects the gas flow rate, a shutoff determination section that determines an abnormality in the gas flow and outputs a gas passage shutoff signal, a shutoff valve that is activated by the shutoff signal, and a power supply. The department is integrated. Since a plurality of gas appliances are connected to a gas meter via piping, the logic for determining when multiple appliances are used becomes complicated, leading to high costs. Furthermore, if at least one of the plurality of gas appliances connected to the gas meter is shut off due to abnormal use, gas is shut off within the gas meter and all gas appliances become unusable.

OBJECTS OF THE INVENTION The present invention solves these problems, simplifies the discrimination logic, and makes it possible to shut off the gas only for the appliances that are subject to the gas shutoff.

Structure of the Invention According to the present invention, a gas flow rate sensor, a shutoff determination section, a shutoff valve, and a power supply section are integrated and installed in the middle of a pipe branching from a gas meter to each gas appliance or in a gas appliance.

This configuration simplifies the decision logic of the shutoff determining section, and in the event of abnormal use, the gas flow is shut off only for the relevant gas appliance, allowing other normally used gas appliances to continue to be used.

DESCRIPTION OF EMBODIMENTS Examples of the present invention will be described below with reference to FIGS. 1 to 5.

Figure 1 is a configuration diagram of a conventional example, and 1 is the main body of the gas meter. 2 is a gas cutoff system including a flow rate sensor, a cutoff determination section, a cutoff valve, and a power supply section. 3, 4, 5,
6 is a gas appliance, 7 is a gas outer pipe, and 8 is a gas inner pipe.

Figure 2 shows an example of the present invention.
7 and 8 are the same as in FIG. 9 is the gas meter body. 10, 11, 12, 13 are 8 branch pipes. 1
Reference numerals 4, 15, 16, and 17 are gas cutoff devices that integrate a flow rate sensor, a cutoff determination section, a cutoff valve, and a power supply section.

In the configuration shown in FIG. 1, the gas meter body 1 has a gas shutoff system 2, so if any abnormal use occurs in any of the gas appliances 3, 4, 5, and 6, the gas meter 1 shuts off the gas. All gas appliances 3, 4, 5, and 6 will be rendered unusable. However, in the configuration shown in FIG. 2, branch pipes 10, 11, 12, and 13 are provided for each of the gas appliances 3, 4, 5, and 6, and a gas cutoff device 14 is installed in the middle of each branch pipe. Since the gas appliances 15, 16, and 17 are interposed, only the gas appliance that has been used abnormally among the gas appliances 3, 4, 5, and 6 can block the gas passage. The gas cutoff devices 14, 15, 16, 17 may be built into the gas appliances 3, 4, 5, 6, respectively.

FIG. 3 shows gas cutoff devices 14, 15, and
16 and 17 are functional block diagrams. Based on the signal from the gas flow rate sensor 18, the cutoff determination unit 19
The gas flow rate and duration limit values shown in FIG. to be displayed.

The shutoff determination unit 19 in the conventional gas shutoff system 2 reads individual gas flow rates from the total of multiple gas flow rates according to a certain logic, and determines the limit of the duration shown in FIG. 3 based on the maximum flow rate value. . For example, in Figure 5, the flow rate can be registered for up to 5 units, but when 3 units, Q ₁ , Q ₂ , and Q ₃ are registered,
If Q ₁ < Q ₃ < Q ₂ , Q ₂ is the maximum flow rate, and the third
The limit value of the duration corresponding to Q ₂ in the figure becomes the determination time. Also, in Figure 5, when the flow rate decreases from Q ₁ + Q ₂ + Q ₃ to Q ₄ , Q ₁ < Q ₃ < Q ₄ < Q ₂
Then, the flow rate larger than Q ₄ is deleted from the registration and made consistent so that Q′ ₁ +Q ₃ =Q ₄ and Q′ ₁ <Q ₁ . Since Q′ ₁ <Q ₃ , the limit value of the duration corresponding to Q ₃ is determined from FIG. According to the present invention, the gas cutoff devices 14, 15, 16, 17 corresponding to the gas appliances 3, 4, 5, 6, respectively, need only monitor the gas flow rate of one unit and determine the corresponding duration time. Therefore, compared to the conventional method, from multiple flow rates to the third
There is no need for arithmetic procedures to determine the maximum flow rate to read the duration of the diagram, and a microcomputer with a small memory capacity can be used, which can lead to cost reductions.

Effects of the Invention As described above, the branch pipes 10 and 1 of the inner pipe 8
Gas cutoff devices 14, 15, every 1, 12, 13,
By configuring a gas supply system using gas appliances 3, 4, 5, and 6 by providing gas appliances 16 and 17, the following effects can be obtained.

(1) When multiple gas appliances are used, only the gas appliance that is used abnormally can be shut off.

(2) When using multiple gas appliances, there is no need for calculation procedures to determine the maximum flow rate, which can lead to cost reductions.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional gas cutoff system piping, Fig. 2 is a block diagram of piping using a gas cutoff device according to an embodiment of the present invention, and Fig. 3 is a block diagram of a conventional gas cutoff system and a gas cutoff system according to the present invention. FIG. 4 is a functional block diagram of the shutoff device, FIG. 4 is a characteristic diagram showing the limit value of duration with respect to gas flow rate, and FIG. 5 is a characteristic diagram showing evaluation of flow rate with respect to changes in gas flow rate. 3, 4, 5, 6... gas appliance, 9... gas meter main body, 14, 15, 16, 17... gas cutoff device, 18... flow rate sensor, 19... cutoff determination section.

Claims (1)

[Claims] 1. A flow rate sensor that is installed in the middle of the gas piping branched from the gas supply source piping to each gas appliance or is built into the gas appliance, and detects the gas flow and transmits a flow rate signal;
A shutoff judgment unit receives a signal from the flow rate sensor, measures the gas flow rate and its duration based on a certain logic, determines whether the gas passage can be shut off, and outputs a shutoff signal and displays the shutoff reason in the event of an abnormality. A fluid control device comprising a unit, a cutoff valve that operates in response to the cutoff signal, and a power supply unit that drives the cutoff determination unit and the cutoff valve, all housed in an integrated case.