JP2002193398A - Fuel shut-off system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel shut-off system which can firmly shut off input and output of fuel according to the seismic coefficient of an earthquake. SOLUTION: A vibration is detected by a measuring part 11, and the measured seismic coefficient of seismic waves is calculated based on the acceleration and periodic time of the vibration. A control unit 12 actuates a shut-off part 15 when the measured seismic coefficient exceeds a predetermined seismic coefficient, thereby shutting off the input and output of fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel shutoff system for urgently shutting off fuel input / output in a fuel tank in the event of an earthquake.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional fuel cutoff system.

In FIG. 5, reference numeral 51 denotes a seismic sensor, 52 denotes a control unit,
53 is an electromagnetic valve and 54 is a display unit.

The seismic sensor 51 shown in FIG. 5 is often installed at the same location as the electromagnetic valve 53 or has a structure in which the seismic sensor 51 and the electromagnetic valve 53 are integrated. The acceleration of the vibration applied to the vessel 51 is measured, and the output is applied to the control unit 52.When the applied acceleration exceeds a predetermined value, the control unit 52 controls the solenoid valve 53. The input / output of fuel to / from the fuel tank T via the fuel pipe P is shut off.

[0005]

As described above, according to the prior art, the acceleration output from the vibration sensor 51 exceeds a predetermined value due to the vibration of a large vehicle or the like passing near the vibration sensor 51. In such a case, the control unit 52 may control the solenoid valve 53 to cause a malfunction such as shutting off the input and output of fuel to and from the fuel tank.

[0006] The seismic resistance of structures such as fuel tanks and fuel pipes depends not only on the acceleration of vibration applied to the structures, but also on the moving speed, displacement, and vibration of the structures accompanying the vibrations of the structures due to earthquakes and the like. It has been clarified that the influence of the acceleration or more is caused by the duration or the like, and only the detection result of the acceleration by the seismic sensor 51 shown in the conventional technique is used.
There is a problem in that shutting off the input and output of fuel to the fuel tank leaves a risk factor.

Although an electromagnetic valve is used to shut off the input and output of fuel to and from the fuel tank, when handling highly flammable fuel, there is a risk of explosion due to sparks caused by opening and closing of contacts when controlling the electromagnetic valve. There is no gender.

When there is a distance from the control unit 52 to the solenoid valve 53, the control line and the electromagnetic valve 53 may be directly hit by a lightning strike on the control line from the control unit 52 to the solenoid valve 53 or a high voltage may be generated by induced lightning. There is a problem that a discharge may occur in the valve 53 and the fuel may be ignited.

Further, according to the prior art, there is a problem that it is not possible to cope with a fire or other danger imminent in the vicinity of the fuel tank, the fuel pipe, etc. instead of a disaster such as an earthquake.

Therefore, a first object of the invention according to the present application is as follows.
In order to solve such conventional problems and to detect seismic waves in the detected vibration, the fuel input / output of the fuel tank is dangerous when the structure such as the fuel tank and fuel pipe is dangerous to the seismic resistance. It is intended to provide a fuel shutoff system for shutting off.

A second object of the invention according to the present application is to
An object of the present invention is to provide a fuel shut-off system that can completely remove a factor that causes a fire from a shut-off unit that shuts off fuel input / output of a fuel tank.

Further, a third object of the invention according to the present application is as follows.
It is an object of the present invention to provide a fuel shutoff system which can shut off fuel input / output of a fuel tank by manual control.

Further, a fourth object of the present invention is to provide a fuel cutoff system which enables remote control.

[0014]

In order to achieve the first object, a first invention is provided in a fuel piping system, wherein a shut-off means for shutting off the input and output of fuel by a control signal and a vibration of the ground surface are provided. Detecting and measuring means for determining whether the detected vibration is a seismic wave, and control means for outputting the control signal to the blocking means when the detected vibration determined to be a seismic wave by the measuring means exceeds a preset value. And a fuel cut-off system.

In order to achieve the first object, a second invention is provided in a fuel pipe system, wherein a shut-off means for shutting off input / output of fuel by a control signal, vibration of the ground surface is detected, and the detected vibration is detected. A plurality of measuring means to determine whether or not a seismic wave, when the detected vibrations determined as seismic waves by the plurality of measuring means exceeds a predetermined value exceeds a predetermined number,
Control means for outputting the control signal to the shut-off means.

In order to achieve the first object, a third invention is the invention according to any one of the above inventions, wherein the measuring means obtains a measured seismic intensity for determining a seismic wave based on a vibration acceleration and a period. The control means is characterized in that a seismic intensity to be compared with the measured seismic intensity is set in advance.

According to a fourth aspect of the present invention, in the first or second aspect, the measuring means determines a seismic wave based on a response speed spectrum of vibration and a natural period. A spectrum intensity of the vibration is obtained, and a value of the spectrum intensity to be compared with the spectrum intensity of the vibration is set in advance by the control means.

A fifth aspect of the present invention for achieving the second object is any one of the above-mentioned inventions, wherein the shut-off means is attached to a fuel pipe system, and controls an air-driven valve for passing and shutting off fuel; An explosion-proof solenoid valve driven by the control signal is provided in a compressed air piping system of the valve.

According to a sixth aspect of the present invention, the control means is switched to a manual control mode upon receiving a manual control instruction signal from an operation means. Upon receiving a cutoff instruction signal, the cutoff means is cut off.

According to a seventh aspect of the present invention, in each of the above aspects, each of the means is divided into a plurality of groups, and a relay section is provided for each of the groups. Are connected to each other via a transmission line to form a system.

[0021]

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

First Embodiment FIG. 1 shows a first embodiment of a fuel cutoff system according to the present invention.

In FIG. 1, reference numeral 11 denotes a measuring unit as measuring means, 12 denotes a control unit as control means, 13 denotes a display unit, 14 denotes an operation unit, 15 denotes a shutoff unit as a shutoff means, and a solenoid valve 151 and the like. It is configured. The control unit 12, the display unit 13, and the operation unit 14 can have either an integral structure or an individual structure.

The value of the measured seismic intensity for controlling the solenoid valve 151 to be in the shut-off state is set in the control unit 12 in advance by an operation from the operation unit 14.

The measuring section 11 detects accelerations of three components of east, west, north, south and up and down from the vibration applied to the measuring section 11, converts the output into a digital value, and converts the digital value into the following equation (1). ) To calculate the measured seismic intensity.

Here, the measured seismic intensity is defined by FIG.
The seismic intensity corresponding to the seismic intensity class shown in (The magnitude and magnitude of the shaking of the earthquake at the time of the earthquake is determined by the observer based on the JMA seismic intensity stage and the bodily sensation and surrounding damage is determined.) The seismic intensity obtained from the output obtained by the calculation method specified by the Japan Meteorological Agency as shown in the following formula (1). There is a feature that the seismic intensity can be calculated at the same time as the occurrence of the earthquake

I = 2 · log (a) + 0.7 + log (k · t) Equation (1) where I: The calculation result on the right side is rounded to an integer such that the measured seismic intensity is 0 to 7. . However, the calculation result is
0 if less than 0.5, 7 if more than 6.5 a: acceleration (gal = cm / sec2) k: coefficient t: period (sec) The measuring unit 11 measures the seismic intensity calculated using the above equation (1). Is output to the control unit 12.If the value of the measured seismic intensity from the measuring unit 11 exceeds the value of the measured seismic intensity for controlling the solenoid valve 151 to be set in a shut-off state, the control unit 12 outputs By controlling the valve 151, the solenoid valve 151 is closed, and the input / output of fuel is shut off.

The vibrations generated when a large vehicle such as a truck passes are different from the seismic waves in the period and the like, so that it is possible to determine whether or not the detected vibrations are seismic waves.

In the above-described embodiment, the measured seismic intensity is obtained by the measuring unit. However, the spectral intensity of the vibration may be obtained as follows.

The control unit 12 sets the value of the spectrum intensity of the vibration for which the electromagnetic valve 151 is to be controlled to the shut-off state by operating the operation unit 14, and determines the east-west, north-south and up-down directions from the vibration applied to the measurement unit 11. The output of the three components is detected and converted into a digital value, and the spectrum intensity of the vibration is calculated from the digital value using the following equation (2).

Here, the spectral intensity of vibration is a measured quantity corresponding to structural damage due to earthquake motion, and is directly obtained from the output of a measuring instrument, similarly to the measured seismic intensity. There is a feature that the spectrum intensity of can be obtained.

[0032]

(Equation 1)

Here, SI: spectral intensity of vibration Sv: response speed spectrum T: natural period h: damping constant The measuring unit 11 sends the value of the spectral intensity of vibration calculated using the above equation (2) to the control unit 12. The control unit 12 controls the electromagnetic valve 151 when the value of the spectral intensity of the output vibration exceeds the value of the spectral intensity of the vibration to be set to the state where the electromagnetic valve 151 is set to the shut-off state. And the solenoid valve 1
51 is closed to shut off fuel input and output.

FIG. 2 shows another fuel cutoff system.

In FIG. 2, reference numerals 11 to 15 are the same as those in FIG. The shut-off unit 15 uses an air-driven valve 154 that does not depend on electric control instead of the electromagnetic valve 151 in FIG. 153 is an air tank that stores compressed air, 154 is an air drive valve provided in the fuel piping system P, 152 is provided in an air piping system that connects the air tank 153 and the air drive valve 154, Is a highly safe explosion-proof solenoid valve with a limited drive current. The drive valve from the air tank 153 to the air drive valve 154 is turned on and off by controlling the explosion-proof solenoid valve 152 by a control signal from the control unit 12. The supply of working air is turned on and off. These explosion-proof solenoid valves 15
2, from the air tank 153 and the air driven valve 154 to the
Is configured.

In the control unit 12, the value of the measured seismic intensity or the spectrum intensity of the vibration to be controlled to shut off the explosion-proof solenoid valve 152 is set in advance by an operation from the operation unit 14. The operation of the unit 12 is the same as in the case of FIG.

When fuel is input / output from / to the fuel tank T via a fuel pipe P, which is a fuel pipe system, the explosion-proof solenoid valve 152 is energized to open the explosion-proof solenoid valve 152 and the air tank 153 The compressed air is supplied to the air driven valve 154 to make the air driven valve 154 conductive.

As described above, the value of the measured seismic intensity or the spectrum intensity of the vibration output from the measuring unit 11 to the control unit 12 is
If the value exceeds the predetermined value, the control unit 12 sets the explosion-proof solenoid valve
Control the explosion-proof solenoid valve 152 to close the air tank 15
Shut off compressed air from 3
To shut off the input and output of fuel through the fuel pipe P.

The air-driven valve 154 outputs an output indicating a shut-off state from a non-voltage contact of an explosion-proof limit switch provided in a valve operating portion (not shown) to the control section 12.
12 causes the display unit 13 to indicate that the fuel input / output is in a cutoff state.

The gas used for the air tank 153 can be a non-flammable gas in addition to the compressed air.
154 will be driven by the nonflammable gas.

Second Embodiment FIG. 3 is a block diagram showing a fuel cutoff system according to a third embodiment of the present invention.

In FIG. 3, reference numerals 11 to 15 are the same as in FIG. 1, and reference numerals 152 to 154 are the same as in FIG. 16 and 17 are measuring units.

In the control unit 12, the value of the measured seismic intensity or the spectrum intensity of the vibration to be controlled so that the explosion-proof solenoid valve 152 is shut off is set in advance by the operation from the operation unit 14 as shown in FIG.
As in the above embodiment shown in FIG.
If the explosion-proof solenoid valve 152 is to be controlled from the operation unit 14 to the shut-off state, the number of outputs from the measurement unit that exceeds the value of the seismic intensity or the spectral intensity of vibration should be at least several.
A reference number serving as a criterion for a majority decision to determine whether or not 152 is in the cutoff state is set. In FIG. 3, the reference number is 2, for example. That is, the present embodiment employs a method of determining by majority vote.

The measuring units 11, 16 and 17 are distributed around the structure such as the fuel tank and the fuel pipe P to be protected or in the area where the structure to be protected is installed. In this case, the measuring units 11, 16, and 17 simultaneously detect the three-component accelerations of east, west, north, south, and up and down from the vibration, convert the output into a digital value, and convert the digital value into the above equation (1) or Using Equation (2), the three measured seismic intensities or the spectral intensities of the vibrations corresponding to each of the measuring units 11, 16 and 17 are calculated.

The measurement units 11, 16 and 17 output the calculated three measured seismic intensities or vibration spectrum intensities to the control unit 12, and the control unit 12 outputs the three measured seismic intensities or vibrations. When the spectral intensity exceeding the predetermined value is two or more of the reference numbers, the explosion-proof solenoid valve 152
To control the air tank 153 in the explosion-proof solenoid valve 152.
Shuts off compressed air from the
Is shut off to shut off fuel input and output.

Next, the operation when the control unit is set to manual control will be described.

If it is necessary to shut off the input / output of fuel urgently due to a fire or other danger approaching the structure to be protected such as the fuel tank T and the fuel pipe P, the operation unit 14 is required.
To set the control unit 12 to manual control.

When the control unit 12 is set to the manual control mode, an instruction signal to shut off fuel is sent from the operation unit 14 to the control unit 12 regardless of the outputs of the measurement units 11, 16 and 17, and the control unit 12 The explosion-proof solenoid valve 152 is controlled by the instruction signal to shut off compressed air from the air tank 153 at the explosion-proof solenoid valve 152, thereby shutting off the air drive valve 154 and shutting off fuel input / output.

Further, the output of the measured seismic intensity or the spectrum intensity of the vibration calculated by the measuring units 11, 16 and 17 is displayed on the display unit 13 via the control unit 12, and the operation on the display of the display unit 13 is viewed. At the discretion of the operator, an instruction signal is sent from the operation unit 14 to the control unit 12, and the control unit 12 controls the explosion-proof solenoid valve 152 based on the instruction signal, and compresses the compressed air from the air tank 153 in the explosion-proof solenoid valve 152. It is also possible to shut off the air and thereby shut off the air drive valve 154 to shut off the fuel input / output.

Third Embodiment FIG. 4 shows a third embodiment of the present invention.

In FIG. 4, reference numerals 11, 13 to 17 are the same as those in FIG. 31 is a control unit, and 32 to 34 are relay units.

FIG. 4 shows the measuring unit 11, the measuring unit 16, and the measuring unit 11 shown in FIG.
The measurement unit 17 and the control unit 12 are grouped together, the display unit 13 and the operation unit 14 are grouped together, and an explosion-proof solenoid valve 152, an air tank 1
If there is a distance between the three groups of 53 and the air-driven valve 154 as a group, the relay unit 32, the relay unit 33 between the three groups
And a connection via the relay section 34.

The group configuration of the above-mentioned components can be arbitrarily changed depending on the situation where the fuel cutoff system is installed.

The control unit 31 is obtained by adding an interface to the relay unit 32 to the control unit 12 shown in FIG.
From the vibrations applied to 11, 16 and 17, east-west, north-south, and three-component acceleration are detected, the output is converted to a digital value, and the measured seismic intensity or spectrum intensity of the vibration is calculated from the digital value. Output to the control unit 31, the control unit 31 controls the explosion-proof solenoid valve 152 when two or more of the three measured seismic intensities or the spectral intensities of the vibrations exceed the predetermined value. The operation shown in FIG.

An output from the control unit 31 for controlling the explosion-proof solenoid valve 152 is applied to the explosion-proof solenoid valve 152 via the relay unit 32 and the relay unit 33. The operation of shutting off the compressed air and thereby shutting off the air drive valve 154 to shut off the input / output of fuel is the same as the operation shown in FIG.

The air-driven valve 154 outputs an output indicating the shut-off state,
A non-voltage contact of an explosion-proof limit switch, which is not shown in the figure, is output from the non-voltage contact of the limit switch to the display unit 13 via the relay unit 33 and the relay unit 34. Show that.

The transmission path between the relay sections 32, 33, and 34 may be any of a wired communication line, a wireless communication line, and a power line carrier, or a combination of the transmission paths and a double transmission path, depending on the installation status of each section. It is possible to use an economical and reliable transmission line by adoption of data, and the data can be either digital or analog.If the digital data format is used, the codec and analog data format should be used for the relay unit. Provides a modem in the relay unit.

[0058]

As described above, according to the present invention, the seismic intensity of an earthquake is calculated as a measured seismic intensity or a spectrum intensity of vibration, and the calculated value is used for the seismic resistance of a structure such as a fuel tank or a fuel pipe. If the value exceeds the dangerous value, the input and output of fuel in the fuel tank can be accurately shut off. At this time, transient and constant transient vibration such as vibration of a large vehicle passing near the measuring means can be achieved. Even if the vibration in the direction is detected, such a vibration is not a seismic wave, and if such a vibration is obtained, a control signal for shutting off the fuel is not output. This can prevent the input and output of the device from being cut off by mistake.

Further, by constituting the shut-off portion with an explosion-proof solenoid valve, an air tank, and an air-driven valve, it is possible to completely eliminate a factor causing a fire from the shut-off portion for shutting off fuel input / output of the fuel tank. .

Further, when fuel is being input / output from / to the fuel tank, the explosion-proof solenoid valve is energized to open the explosion-proof solenoid valve, and compressed air is supplied from the air tank to the air drive valve.
If the air-driven valve is kept in a conductive state and the power is stopped due to a power failure or the like, the power to the explosion-proof solenoid valve is cut off and the explosion-proof solenoid valve is closed, so that the air-driven valve is removed from the air tank. The supply of compressed air is cut off and the system is shut off, shutting off fuel input and output and placing the equipment on the safe side.

The explosion-proof solenoid valve is an explosion-proof solenoid valve, but since it is an electromagnetic valve, by installing it at a distance from the air-driven valve, an effect is obtained that the fuel can be shut off more safely.

Further, a plurality of measuring means are dispersed and arranged around a fuel tank, a fuel pipe or the like to be protected, or in an area where the structure to be protected is provided, and the measured seismic intensity or vibration is obtained from the output. By obtaining the spectral intensity of the above and controlling the cutoff unit using the logic of majority decision based on the result, the accuracy of the earthquake detection can be further improved, and a reliable fuel supply can be achieved.

Further, by setting the control means to the manual control mode, an instruction signal is forcibly sent from the operation unit to the control means regardless of the outputs of the plurality of measuring means, and the explosion-proof solenoid valve is controlled to drive the pneumatic drive. The safety can be improved by shutting off the fuel by setting the valve to the shut-off state, and the effect that flexible operation can be performed by switching between automatic control and manual control is obtained.

Further, for example, a plurality of measuring means, a display unit, an operation unit, an explosion-proof solenoid valve, an air tank, and an air-driven valve are divided into three groups, and these groups are connected to each other via a relay unit. By doing so, it is possible to configure a fuel cut-off system by remote control even when the above three groups are separated from each other, and use a communication method according to the existing transmission line for the transmission line between the relay units. Thus, the effect of economically configuring the fuel cutoff system can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a fuel cutoff system according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the fuel cutoff system of FIG. 1;

FIG. 3 is a block diagram of a fuel cutoff system showing a second embodiment of the present invention.

FIG. 4 is a block diagram of a fuel cutoff system showing a third embodiment of the present invention.

FIG. 5 is a block diagram of a prior art fuel cutoff system;

[Figure 6] JMA seismic intensity class commentary chart

[Description of Signs] 11 ... Measurement unit 12 ... Control unit 13 ... Display unit 14 ... Operation unit 15 ... Interruption unit 151 ... Electromagnetic valve 152 ... Explosion-proof electromagnetic valve 153 ... Air tank 154 ... Air-driven valve 16 ... Measurement unit 17 ... Measurement unit 31 Control unit 32 Relay unit 33 Relay unit 34 Relay unit 51 Seismic sensor 52 Control unit 53 Solenoid valve 54 Display unit

Claims (7)

[Claims] 1. A shutoff means provided in a fuel piping system for shutting off input / output of fuel according to a control signal, a measuring means for detecting vibration of the ground surface and judging whether or not the detected vibration is a seismic wave, Control means for outputting the control signal to the shut-off means when the detected vibration determined by the means to be a seismic wave exceeds a preset value. 2. A shutoff means provided in a fuel pipe system for shutting off input / output of fuel by a control signal, a plurality of measuring means for detecting ground surface vibration and determining whether the detected vibration is a seismic wave, Control means for outputting the control signal to the cutoff means when the number of detected vibrations determined as seismic waves by the plurality of measurement means exceeds a predetermined value exceeds a predetermined number. Fuel shutoff system. 3. The method according to claim 1, wherein the measuring means obtains a measured seismic intensity for determining a seismic wave based on a vibration acceleration and a period, and the control means sets a seismic intensity to be compared with the measured seismic intensity in advance. The fuel cutoff system according to claim 1. 4. The method according to claim 1, wherein the measuring unit obtains a spectrum intensity of the vibration for determining the seismic wave based on a response speed spectrum of the vibration and a natural period. The fuel cutoff system according to claim 1, wherein the fuel cutoff system is set in advance. 5. The air cutoff means is attached to a fuel pipe system, and controls an air drive valve for passing and shutting off fuel, and an explosion proof driven by the control signal provided in a compressed air pipe system of the air drive valve. The fuel cutoff system according to any one of claims 1 to 4, wherein the fuel cutoff system comprises a solenoid valve. 6. The control means is switched to a manual control mode upon receiving a manual control instruction signal from an operation means,
The fuel cutoff system according to any one of claims 1 to 5, wherein the cutoff means is cut off when a cutoff instruction signal is received from the operation means. 7. Each of the means is divided into a plurality of groups,
7. The fuel according to claim 1, wherein a relay unit is provided for each of the groups, and a system is configured by connecting the relay units of each group via a transmission line. Blocking system.