JP2007127010A - Energy generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an energy generation system in which gas leakage is accurately determined in a short time even in a very large pressure range. <P>SOLUTION: This energy generation system comprises a main stop valve H100 and a shut-off valve H21 forming a closed space in a high-pressure gas pipe 74, a signal amplifier 102 amplifying the pressure variation width of a high-pressure gas pipe 74 detected by a pressure detection part 100, and a leakage determination part 105 determining for leakage according to a pressure variation after the amplification. Normally, the signal amplifier 102 is not used and, therefore, the pressure can be detected in a wide range. To determine the leakage, the high-pressure gas pipe 74 is sealed, and a slight pressure variation width is amplified by the signal amplifier 102. Consequently, the leakage can be detected with high accuracy in a short time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an energy generation system including an energy generation device that generates energy upon receiving a supply of fuel gas, and particularly relates to a technique effective in improving the accuracy of detecting an abnormality in a closed space formed in a gas passage.

  In recent years, as an energy generation system, for example, a fuel cell system using a fuel cell that generates power by an electrochemical reaction between a fuel gas and an oxidizing gas (hereinafter referred to as a reaction gas) has attracted attention. In a vehicle fuel cell system mounted on a vehicle, the fuel gas tank to be mounted is increased in pressure (for example, the pressure is set to 70 MPa) in order to extend the cruising distance of the vehicle.

  By the way, the detection range of the pressure sensor for detecting the pressure of the high-pressure gas pipe needs to cover the pressure that can be taken by the high-pressure gas pipe to be attached. That is, as the pressure of the fuel gas tank increases as described above, the pressure of the high-pressure gas pipe connected to the fuel gas tank also rises, so the detection range of the pressure sensor needs to be a very large pressure range.

On the other hand, when performing abnormality determination, for example, when performing gas leak determination, the amount of pressure change used as a reference is so small as to be buried in tolerance with respect to the sensor detection range of the very large pressure range. Here, for example, those disclosed in Patent Documents 1 and 2 are known as fuel cell systems capable of detecting hydrogen leakage based on the amount of pressure drop in the hydrogen supply path.
JP 2003-148252 A JP 2003-308866 A

However, in order to detect a slight pressure change due to gas leakage while corresponding to the very large pressure range described above, it is necessary to take one of the following means.
・ Use high-performance sensors with high resolution.
-Provide multiple sensors with different ranges,
・ Reduce the volume of the gas piping subject to leak detection so that the amount of pressure change relative to the amount of gas leak increases.
・ Long detection time is required to detect pressure change.

  However, the above-described means have problems that the cost of components increases, the configuration of components and layout are restricted due to design requirements for gas piping, and it takes time to determine gas leaks.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an energy generation system capable of performing abnormality determination with high accuracy in a short time even when targeting a very large pressure range. To do.

  An energy generation system according to the present invention includes an energy generation device that generates energy upon receiving fuel gas supply, a gas passage that connects the energy generation device and a gas supply source, and a seal that forms a closed space in the gas passage. Stopping means, pressure detecting means installed in a section of the gas passage where the closed space is formed, and outputting a signal corresponding to the pressure in the section, based on the output of the pressure detecting means, An energy generation system including an abnormality determination unit that performs abnormality determination includes a gain changing unit that changes an output gain of the pressure detection unit in conjunction with an operation of the sealing unit. The gain changing means amplifies the output gain more than before when determining the abnormality of the closed space.

  According to such a configuration, the output gain with respect to the input of the pressure detection means (pressure in the gas passage) is automatically switched between normal operation and abnormality determination in conjunction with the operation of the sealing means. In normal operation, the pressure in the gas passage can be detected in a wide pressure range by setting the output gain of the pressure detection means to be relatively small.

  On the other hand, when performing the abnormality determination of the closed space, even if the input change (pressure change width) to the pressure detecting means is slight by amplifying the output gain of the pressure detecting means than in the case of normal operation, Since the signal (for example, voltage value) output from the pressure detection means is amplified, it is possible to detect an abnormality with high accuracy in a short time.

  An energy generation system according to the present invention includes an energy generation device that generates energy upon receiving fuel gas supply, a gas passage that connects the energy generation device and a gas supply source, and a seal that forms a closed space in the gas passage. Stopping means, pressure detecting means installed in a section of the gas passage where the closed space is formed, and outputting a signal corresponding to the pressure in the section, based on the output of the pressure detecting means, In an energy generation system including an abnormality determination unit that performs an abnormality determination, an output unit that outputs a predetermined signal when performing an abnormality determination of the closed space; and an output of the pressure detection unit that receives the predetermined signal And a gain changing means for changing the gain. The gain changing means amplifies the output gain more than before when determining the abnormality of the closed space. The predetermined signal is a signal output when it is determined that the condition for executing abnormality detection is met.

  According to such a configuration, the output gain with respect to the input of the pressure detection means (pressure in the gas passage) is automatically set during normal operation and abnormality determination according to transmission / reception of a predetermined signal output from the output means. In the same way as described above, the pressure in the gas passage can be detected in a wide pressure range during normal operation, while an abnormality can be detected with high accuracy in a short time when determining an abnormality in a closed space. It becomes.

  The energy generation system of the present invention may further include offset means for offsetting the output of the pressure detection means with reference to a predetermined value.

  According to such a configuration, the pressure when there is no abnormality in the closed space is set as a reference, that is, the pressure when there is no abnormality in the closed space is set as the center value of the output range of the pressure detection means, It is possible to make an abnormality determination. As a result, it is possible to detect not only an abnormality when the pressure in the closed space decreases but also an abnormality when the pressure increases.

  Here, as an example in which the pressure in the closed space decreases, for example, when the gas leaks from the inside to the outside of the gas piping that defines the closed space due to wall cracking (hereinafter referred to as external leakage), or the closed space When the gas leaks inside the gas pipe defining the gas (hereinafter referred to as internal leakage), that is, due to the closing abnormality of the sealing means (for example, sealing failure), the gas flows upstream or downstream from the closed space. It may have leaked. On the other hand, as an example in which the pressure in the closed space increases, there is a case where gas flows into the closed space from upstream or downstream due to internal leakage, for example.

  In the energy generation system of the present invention, the gas supply source may be a high-pressure hydrogen tank, and the sealing means may be a main stop valve of the high-pressure hydrogen tank and a valve installed downstream of the main stop valve. Good.

  In such a configuration, since the closed space formed between the main stop valve of the high-pressure hydrogen tank and the valve installed downstream of the main stop valve becomes a high-pressure portion, the pressure detection installed in the closed space The pressure range of the means is usually large, but the output gain with respect to the input of the pressure detection means is variable (can be amplified) when an abnormality is detected, so that even if the input pressure fluctuation width is small, it is buried in tolerance. It is possible to detect without losing.

  The energy generation system of the present invention may be a fuel cell system in which the energy generation device is a fuel cell. Further, the energy generating device is not limited to the fuel cell as long as it is a device that generates electric energy or mechanical energy by receiving supply of fuel gas, and may be, for example, a gas engine. Further, the fuel gas refers to, for example, hydrogen, reformed gas, CNG, and the like.

  The abnormality determination means may determine gas leakage in the closed space.

  According to the present invention, the output gain with respect to the input of the pressure detection means is automatically switched between the normal operation and the abnormality determination in conjunction with the operation of the sealing means, so that the gas passage has a wide pressure range during the normal operation. While the internal pressure can be detected, the abnormality can be detected with high accuracy in a short time when the abnormality of the closed space is determined.

  Next, an embodiment of the energy generation system according to the present invention will be described. Hereinafter, the case where this energy generation system is applied to an in-vehicle fuel cell system of a fuel cell vehicle will be described. However, the present invention is not limited to such an application example, and can be applied to any moving body such as a ship, an aircraft, a train, and a walking robot. And, for example, a stationary power generation system in which a fuel cell is used as a power generation facility for a building (house, building, etc.) is also possible.

  As shown in FIG. 1, air (outside air) as an oxidizing gas is supplied to an air supply port of the fuel cell 20 via an air supply path 71. The air supply path 71 is provided with an air filter A1 that removes particulates from the air, a compressor A3 that pressurizes the air, a pressure sensor P4 that detects the supply air pressure, and a humidifier A21 that adds required moisture to the air. The compressor A3 is driven by a motor (auxiliary machine). The motor is driven and controlled by a control unit 50 described later. The air filter A1 is provided with an air flow meter (flow meter) (not shown) that detects the air flow rate.

  The air off gas discharged from the fuel cell 20 is discharged to the outside through the exhaust path 72. The exhaust path 72 is provided with a pressure sensor P1 that detects the exhaust pressure, a pressure adjustment valve A4, and a heat exchanger for the humidifier A21. The pressure sensor P <b> 1 is provided in the vicinity of the air exhaust port of the fuel cell 20. The pressure adjustment valve A4 functions as a pressure regulator that sets the supply air pressure to the fuel cell 20.

  Detection signals (not shown) of the pressure sensors P4 and P1 are sent to the control unit 50. The control unit 50 sets the supply air pressure and the supply air flow rate to the fuel cell 20 by adjusting the rotation speed of the compressor A3 and the valve opening degree of the pressure adjustment valve A4.

  Hydrogen gas as fuel gas is supplied from a hydrogen supply source (gas supply source) 30 to a hydrogen supply port of the fuel cell 20 via a high-pressure gas pipe 74 as a fuel supply passage (gas passage). The hydrogen supply source 30 corresponds to, for example, a high-pressure hydrogen tank, but may be a so-called fuel reformer, a hydrogen storage alloy, or the like. As the high-pressure gas from the gas supply source, for example, a gas pressure of 10 MPa to 100 MPa can be adopted, and in the case of high-pressure hydrogen gas, 35 MPa or 70 MPa can be adopted.

  The high-pressure gas pipe 74 includes a main stop valve (shutoff valve) H100 that supplies or stops supplying hydrogen from the hydrogen supply source 30, a pressure sensor P6 that detects the supply pressure of hydrogen gas from the hydrogen supply source 30, and a fuel cell. A hydrogen pressure control valve H9 for reducing and adjusting the supply pressure of hydrogen gas to 20; a pressure sensor P9 for detecting hydrogen gas pressure downstream of the hydrogen pressure control valve H9; and a space between the hydrogen supply port of the fuel cell 20 and the high pressure gas pipe 74. A shutoff valve H21 that opens and closes and a pressure sensor P5 that detects the inlet pressure of the hydrogen gas fuel cell 20 are provided.

  As the pressure regulating valve H9, for example, a pressure regulating valve that performs mechanical pressure reduction can be used, but a valve whose opening degree is linearly or continuously adjusted by a pulse motor may be used. Detection signals (not shown) of the pressure sensors P5, P6, and P9 are supplied to the control unit 50.

  The hydrogen gas that has not been consumed in the fuel cell 20 is discharged to the hydrogen circulation path 75 as a hydrogen off-gas and returned to the downstream side of the pressure regulating valve H9 in the high-pressure gas pipe 74. The hydrogen circulation path 75 includes a temperature sensor T31 that detects the temperature of the hydrogen off-gas, a shutoff valve H22 that communicates / blocks the fuel cell 20 and the hydrogen circulation path 75, a gas-liquid separator H42 that collects moisture from the hydrogen off-gas, and a hydrogen A drain valve H41 that collects the generated water in a tank (not shown) outside the hydrogen circulation path 75, a hydrogen pump H50 that pressurizes the hydrogen off-gas, and a backflow prevention valve H52 are provided.

  The shutoff valves H21 and H22 close the anode side of the fuel cell 20. A detection signal (not shown) of the temperature sensor T31 is supplied to the control unit 50. The operation of the hydrogen pump H50 is controlled by the control unit 50. The hydrogen off-gas merges with the hydrogen gas through the high-pressure gas pipe 74 and is supplied to the fuel cell 20 for reuse. The backflow prevention valve H52 prevents the hydrogen gas in the high pressure gas pipe 74 from flowing back to the hydrogen circulation path 75 side. The main stop valve H100 and the cutoff valves H21 and H22 are driven by signals from the control unit 50.

  The hydrogen circulation path 75 is connected to the exhaust path 72 by the purge flow path 76 via the discharge control valve H51. The discharge control valve H51 is an electromagnetic shut-off valve, and discharges (purges) hydrogen off-gas to the outside by operating according to a command from the control unit 50. By performing this purge operation intermittently, it is possible to prevent the hydrogen off-gas circulation from being repeated, the impurity concentration of the hydrogen gas on the fuel electrode side being increased, and the cell voltage from being lowered.

  Further, a cooling passage 73 for circulating the cooling water is provided at the cooling water inlet / outlet of the fuel cell 20. In the cooling path 73, a temperature sensor T1 that detects the temperature of the cooling water drained from the fuel cell 20, a radiator (heat exchanger) C2 that radiates the heat of the cooling water to the outside, and a pump that pressurizes and circulates the cooling water. C1 and a temperature sensor T2 for detecting the temperature of the cooling water supplied to the fuel cell 20 are provided. The radiator C2 is provided with a cooling fan C13 that is rotationally driven by a motor.

  The fuel cell 20 is configured as a fuel cell stack in which a required number of unit cells that generate power upon receiving supply of fuel gas and oxidizing gas are stacked. The electric power generated by the fuel cell 20 is supplied to a power control unit (not shown). The power control unit consists of an inverter that drives the drive motor of the vehicle, an inverter that drives various auxiliary devices such as a compressor motor and a motor for a hydrogen pump, and charging to the secondary battery and motors from the secondary battery. A DC-DC converter or the like for supplying power is provided.

  The control unit 50 receives control information from a requested load such as an accelerator signal of a vehicle (not shown) and sensors (pressure sensors, temperature sensors, flow sensors, output ammeters, output voltmeters, etc.) of each part of the fuel cell system. Control the operation of valves and motors.

  The control unit 50 is configured by a control computer system (not shown). This control computer system has a known configuration such as a CPU, ROM, RAM, HDD, input / output interface, and display, and is configured by a commercially available control computer system.

  As will be described later, when it is determined that a command or a flag for instructing a gas leak determination operation is set (event occurrence) in the main control program (not shown), the control unit 50 performs a gas leak determination process.

  During normal operation, the pressure of the fuel gas discharged from the hydrogen supply source 30 and supplied to the fuel cell 20 is monitored using the pressure sensor P6, and based on this, the hydrogen pressure regulating valve H9 is controlled.

  The pressure sensor P6 of the present embodiment has a pressure range with a very large detection range corresponding to a high pressure. Therefore, in a normal operation state, the pressure change amount used as a reference when performing the gas leak determination is so small as to be buried in tolerance with respect to the sensor detection range of the very large pressure range.

  Therefore, in this embodiment, the configuration shown in FIG. 2 is adopted. As shown in the figure, the pressure sensor P6 has a predetermined offset by a pressure detection unit (pressure detection means) 100 that converts the pressure of the high-pressure gas pipe 74 into a pressure signal S1 as an electric signal, and a switching signal S2 described later. An offset adder (offset unit) 101 that adds a value to the pressure signal S1, a signal amplifier (gain changing unit) 102 that amplifies the offset signal S3, and a signal S5 as a sensor output from the pressure detection unit 100 A pressure signal switching unit 103 that selects either the signal S1 or the signal S4 from the signal amplifier 102 in accordance with an instruction of a switching signal (predetermined signal) S2.

  Furthermore, the control unit 50 receives the signal S5 from the pressure signal switch 103, that is, the detected pressure signal S1 or the signal S4 after further amplifying the pressure signal S1 by offsetting the pressure signal S1, A / D converter 104, A A leakage determination unit (abnormality determination means) 105 that performs leakage determination (abnormality determination) based on the output of the / D converter 104 is provided. Further, the leakage determination unit 105 outputs a switching signal S2 for requesting the pressure sensor P6 to switch the output. The switching signal S2 is a signal that is output when the control unit 50 determines that the condition for executing the leak detection (abnormality detection) is satisfied. Upon receipt of this signal, the main stop valve H100 as the sealing means is closed. To be spoken. The control unit 50 may be an ECU for the fuel cell 20.

  The control flow of the gas leak determination process in the present embodiment is shown in FIG. First, in step ST1, the control unit 50 determines whether or not it is in the leakage determination period. When it is not the leakage determination period (step ST1: NO), the control unit 50 opens the high-pressure gas pipe 74. That is, the main stop valve H100 and the shutoff valve H21 are kept open (step ST2). Thereafter, the leakage determination unit 105 outputs “not determined” as the switching signal S2 (step ST3).

  This is the state during normal operation, and the pressure detected by the pressure detection unit 100 is given to the leak determination unit 105 via the pressure signal switch 103 and the A / D converter 104 to control the hydrogen pressure regulating valve H9 and the like. Used. In this state, the pressure sensor P6 of the present embodiment outputs a voltage of 0.5 V for a pressure of 0 MPa and 4.5 V for a pressure of 50 MPa. That is, the detection range of the pressure sensor P6 is a large pressure range (50 MPa) corresponding to the gas pressure of the high-pressure gas pipe 74.

  When it determines with it being in a leak determination period in step ST1 (step ST1: YES), the control part 50 seals the high pressure gas piping 74, and forms a closed space. That is, the main stop valve H100 and the shutoff valve H21 as sealing means are closed (step ST4). The pressure detection unit 100 detects the absolute pressure value of the high-pressure gas pipe 74 at this time, and the leak determination unit 105 stores this value (referred to as initial pressure) (step ST5).

  Thereafter, the leakage determination unit 105 outputs “determining” as the switching signal S2 (step ST6). In this state, a predetermined voltage (offset value) based on the initial pressure is added to the pressure signal S1 by the offset adder 101, and further amplified by the signal amplifier 102. The signal S4 output from the signal amplifier 102 passes through the pressure signal switch 103, and is supplied to the leak determination unit 105 via the A / D converter 104.

  For example, when the initial pressure is 15 MPa, the offset value is added in the offset adder 101 so that 15 MPa becomes the median value of the output voltage range (0.5 to 4.5 V) of the pressure detection unit 100. Further, in the signal amplifier 102, the signal S 3 is amplified by the signal amplifier 102 so that the range of ± 0.5 MPa of the initial pressure 15 MPa becomes the detection range of the pressure detection unit 100. As a result, the pressure sensor P6 outputs a voltage of 0.5 V for a pressure of 14.5 MPa and a voltage of 4.5 V for a pressure of 15.5 MPa.

  That is, even when the pressure in the closed space slightly varies from the initial pressure, the signal is amplified so that the output value varies greatly.

  FIG. 4 shows a comparison of the pressure sensor output voltage during non-determination (during normal operation) and during determination. During normal operation, the main stop valve H100 and the shut-off valve H21 are in an open state, and the switching signal S2 is Lo indicating “not determined”. The pressure sensor P6 outputs a signal of 0.5 to 4.5 V with 0 to 50 MPa as a detection range.

  On the other hand, during the leak determination, the main stop valve H100 and the shutoff valve H21 are in a sealed state, and the switching signal S2 is Hi indicating “during determination”. The pressure sensor P6 outputs a signal of 0.5 to 4.5 V with the initial pressure of 15 MPa as the center and 14.5 to 15.5 MPa as the detection range.

  That is, the output gain of 4 [V] / 50 [MPa] = 0.08 [V / MPa] during normal operation is 4 [V] / 1 [MPa] = 4 [V] during the leak determination. / MPa] output gain, and 50 times the detection accuracy can be obtained.

  The leak determination unit 105 performs the following leak determination process. First, in step ST7, “leakage amount ΔP = initial pressure−current pressure” is calculated. When a leak occurs in the main stop valve H100, the current pressure detected by the pressure sensor P6 increases from the initial pressure. On the other hand, when a leak occurs outside from the high pressure gas pipe 74, which is a high pressure gas pipe, or when a leak occurs at the shutoff valve H21, the current pressure detected by the pressure sensor P6 is lower than the initial pressure.

  In step ST8, the absolute value of the leak amount ΔP is compared with a predetermined specified value K. If the leak amount ΔP exceeds the specified value K, it is determined that a leak has occurred. In step ST9, the leak occurrence process is performed. I do. Examples of the leak generation process include a process of displaying a warning to the user and stopping the system.

  If the leakage amount is equal to or less than the specified value K, step ST6 and subsequent steps are repeated until the leakage determination period (for example, 3 seconds) ends (step ST10). After the end of the leakage determination period, the switching signal S2 is set to “not determined” and the normal operation is resumed.

  As described above, in the fuel cell system of this embodiment, the detection accuracy can be increased by temporarily amplifying the output gain of the pressure sensor P6 during the leak determination period. Therefore, it is possible to determine the gas leakage in a short time without changing the sensor parts and the piping layout.

  FIG. 5 is a modification of the present embodiment. FIG. 6 is a time chart showing the relationship between the opening and closing of the main stop valve H100 and the shutoff valve H21, the pressure switching signal Hi / Lo, and the pressure sensor output voltage.

  In the present modification, the switching signal S2 that is transmitted and received between the pressure sensor P6 and the control unit 50 in the above embodiment is omitted. Since the schematic configuration is the same as that of the above-described embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  The control unit 50 includes a voltage adder 110 that outputs a high voltage (a value exceeding the normal range, for example, 12 V) by receiving the signal S10 from the leakage determination unit 105. A signal S5 flows between the pressure sensor P6 and the A / D converter 104, and the output (potential, voltage) of the voltage adder 110 is added to the potential (voltage) of the signal line through which the signal S5 flows. The

  The pressure sensor P6 monitors the potential (voltage) of the signal line that flows through the signal S5, and detects a voltage addition determiner (comparator) 111 that detects that a high voltage has been added by the voltage adder 110, and a voltage And a timer 112 that is turned on for a predetermined time in response to the signal S11 provided from the addition determination unit 111. The timer 112 gives a switching signal S12 to the pressure signal switch 103 and the offset adder 101.

  In the present modification, switching between the normal operation and the leakage determination period is performed as follows. First, at the start of leak determination, a predetermined signal S10 is supplied from the leak determination unit 105 to the voltage adder 110, and the voltage adder 110 adds a voltage of 12V to the signal S5 output from the pressure sensor P6. The time for the voltage adder 110 to generate a voltage may be a length that can be determined by the voltage addition determiner 111 described later.

  Then, as shown in FIG. 6, the pressure sensor output voltage protrudes outside the normal range at the boundary where the normal operation state shifts to the leakage determination period. When this protrusion is detected by the voltage addition determiner 111, the voltage addition determiner 111 issues a signal S11 for turning on the timer 112. The timer 112 provides the offset adder 101 and the pressure signal switch 103 with a switching signal S12 of “being determined”. This starts the leak determination period.

  After a predetermined time, the timer 112 is turned off. The timer 112 gives a switching signal S <b> 12 of “not determined” to the offset adder 101 and the pressure signal switch 103. The predetermined signal S10 is a signal that is output when the control unit 50 determines that the condition for executing the leak detection (abnormality detection) is satisfied, and upon receiving this signal, the main stop valve H100 as a sealing means. Is closed.

  Thus, in this modification, since the pressure signal switch 103 is switched using the signal S5 output from the pressure sensor P6, the switching signal S2 between the pressure sensor P6 and the control unit 50 may be omitted. it can. In addition, about the other structure in leak determination processing, such as leak amount determination, it is the same as the said embodiment.

  In the above embodiment, the output gain of the pressure sensor P6 is switched in response to the predetermined signals S2 and S10 of the control unit 50. However, as another embodiment, the change state of the signal S1 of the pressure sensor P6 is monitored, When the pressure signal does not change (for example, when the signal value is zero or the signal value is stuck to the upper limit value of the measurement range), the pressure signal switch 103 is automatically switched to the signal amplifier 102 side. May be.

  Also, hydrogen and CNG compressed to high pressure used in fuel cells and CNG engines are released from the gas tank (gas supply source) and flow into the gas passage so that the temperature rapidly decreases (for example, below zero degrees). Therefore, when measuring the gas pressure in the gas passage, it is necessary to consider the influence of the temperature in the gas passage. Therefore, in the case of a system configuration having a temperature sensor in the gas passage, the abnormality determination means refers to the gas temperature information and sets the signal gain (output gain of the pressure detection means), so that the accuracy can be improved. A good judgment can be made.

1 is a system configuration diagram schematically illustrating an embodiment of an energy generation system according to the present invention. It is the block diagram which showed the structure which performs gas leak determination by the energy generation system. It is a control flow at the time of performing gas leak determination by the same energy generation system. It is the chart which showed the output voltage of the pressure sensor before and behind a gas leak determination period. It is the modification of an energy generation system, and is the block diagram which showed the structure which performs gas leak determination. In the modification, it is the chart figure which showed the output voltage of the pressure sensor before and behind the gas leak determination period.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Fuel cell, 30 ... Hydrogen supply source (gas supply source, high pressure hydrogen tank), 50 ... Control part, 74 ... High pressure gas piping, 100 ... Pressure detection part (pressure detection means), 101 ... Offset adder (offset means) , 102 ... Signal amplifier (gain changing means), 103 ... Pressure signal switch, 105 ... Leak determination unit (abnormality determination means), 110 ... Voltage adder, 111 ... Voltage addition determiner, 112 ... Timer, H21 ... Cut off Valve (sealing means, valve installed downstream of the main stop valve), H100 ... main stop valve (sealing means), P6 ... pressure sensor, S2 ... switching signal (predetermined signal), S12 ... switching signal (predetermined) Signal),

Claims (7)

An energy generator for generating energy upon receipt of fuel gas; a gas passage connecting the energy generator and a gas supply source; sealing means for forming a closed space in the gas passage; A pressure detection unit that is installed in a section where the closed space is formed and outputs a signal corresponding to a pressure in the section; an abnormality determination unit that performs an abnormality determination of the closed space based on an output of the pressure detection unit; In an energy generation system comprising
An energy generation system comprising gain changing means for changing the output gain of the pressure detecting means in conjunction with the operation of the sealing means. An energy generator for generating energy upon receipt of fuel gas; a gas passage connecting the energy generator and a gas supply source; sealing means for forming a closed space in the gas passage; A pressure detection unit that is installed in a section where the closed space is formed and outputs a signal corresponding to a pressure in the section; an abnormality determination unit that performs an abnormality determination of the closed space based on an output of the pressure detection unit; In an energy generation system comprising
Output means for outputting a predetermined signal when performing the abnormality determination of the closed space;
An energy generation system comprising: a gain changing unit that receives the predetermined signal and changes an output gain of the pressure detecting unit.   The energy generation system according to claim 1, wherein the gain changing unit amplifies the output gain more than before when determining the abnormality of the closed space.   The energy generation system according to any one of claims 1 to 3, further comprising offset means for offsetting an output of the pressure detection means with reference to a predetermined value. The gas supply source is a high-pressure hydrogen tank;
The energy generation system according to any one of claims 1 to 4, wherein the sealing means is a main stop valve of the high-pressure hydrogen tank and a valve installed downstream of the main stop valve.   The energy generation system according to claim 1, wherein the energy generation device is a fuel cell. The energy generation system according to claim 1, wherein the abnormality determination unit determines a gas leak in the closed space.

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