Gas-powered power generation system

Abstract

To provide a gas consumption type power generation system that can reduce as much as possible a period required for a control unit of the gas consumption type power generation system to determine that a gas non-use condition is satisfied, and when a gas meter does not determine that a non-leakage condition is satisfied, can perform similar determination.SOLUTION: In a gas consumption type power generation system S, a control unit 22 determines that a gas non-use condition is satisfied when the cumulative number of reference periods longer than a period for setting determination included in all continuous gas non-use periods occurring during all stand-by processing performed in a processing target period becomes the target number of times equal to or more than the set number of times. The cumulative number of the reference periods is derived by, for each of the continuous gas non-use periods occurring while the stand-by processing is performed, counting the number of reference periods included in the remaining period obtained by subtracting a predetermined margin period from the continuous gas non-use period, and accumulating the number of the reference periods included in each of the continuous gas non-use periods.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a gas consumption type power generation system including a gas consumption type power generation unit that consumes fuel gas to generate power, an information output unit that can output information, and a control device.

Background Art

[0002] A gas meter such as a so-called microcomputer meter is configured to operate an alarm or shut off the supply of supply gas when a non-leakage condition indicating that the flow rate of supply gas such as city gas is zero or low does not occur the set number of times during the leakage determination period.

[0003] Patent Document 1 (Japanese Patent Application Laid-Open No. 2016-42411) describes a technique for avoiding the gas meter from operating an alarm or shutting off the supply of supply gas as described above by intentionally creating a period during which the gas consumption type power generation system does not consume fuel gas (for example, gas obtained by reforming supply gas such as city gas). For example, the gas consumption type power generation system described in Patent Document 1 is controlled to stop for one day every 27 days (that is, three days before the elapse of 30 days, which is the leakage determination period). Since the supply gas is not used in the gas consumption type power generation system during the one-day stop, it is expected that the gas meter will determine that a non-leakage condition indicating that the flow rate of supply gas such as city gas is zero or low has occurred the set number of times during the leakage determination period.

[0004] Furthermore, even if an attempt is made to intentionally create a period during which the gas-consuming power generation unit of a gas-consuming power generation system does not consume supplied gas, and thus satisfy the above-mentioned non-leakage conditions, if gas is consumed by a heat source unit for hot water supply or other equipment attached to the gas-consuming power generation unit, the above-mentioned non-leakage conditions will not be satisfied. To address such problems, it is preferable that the control device of the gas-consuming power generation system also sets predetermined gas non-use conditions corresponding to the non-leakage conditions determined by the gas meter, in order to estimate whether or not the gas meter has determined that the non-leakage conditions have been met, and then determines whether or not those gas non-use conditions have been met. If the gas non-use conditions are not met within a predetermined period, it is preferable that the control device of the gas-consuming power generation system issues a message to the user of the gas-consuming power generation system advising them to reduce gas consumption. Patent Document 2 (Japanese Patent Publication No. 2017-22078) describes a control device for a gas-consuming power generation system (an energy supply system equipped with a fuel cell unit) that monitors gas consumption in the gas-consuming power generation unit and the heat source unit for hot water supply, and outputs a message from the information output unit to the user prompting them to reduce gas consumption if a predetermined gas non-use condition (i.e., the non-supply period, which is the duration of time during which gas is not consumed in the gas-consuming power generation unit and the heat source unit for hot water supply) is not met within a specific period. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-42411 [Patent Document 2] Japanese Patent Publication No. 2017-22078 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Although not described in Patent Document 2, for example, the heat source unit for hot water supply can send a signal indicating that gas combustion has stopped and a signal indicating that gas combustion has started to the control device of the gas-consuming power generation system. This allows the control device of the gas-consuming power generation system to understand not only the period when the gas-consuming power generation unit, which it controls, did not consume gas, but also the period when the heat source unit for hot water supply, which it does not control, did not consume gas.

[0007] However, there is a time lag between the timing when the control device of the gas-consuming power generation system receives a signal from the heat source unit for hot water supply indicating that gas combustion has stopped, and the actual timing when gas combustion in the heat source unit for hot water supply stops. Furthermore, there is a time lag between the timing when the control device of the gas-consuming power generation system receives a signal from the heat source unit for hot water supply indicating that gas combustion has started, and the actual timing when gas combustion in the heat source unit for hot water supply starts. As a result, the time period that the control device of the gas-consuming power generation system can grasp, which can be estimated to be a period in which gas is not consumed in the gas-consuming power generation unit and gas is not consumed in the heat source unit for hot water supply (i.e., the "duration of non-supply" in Patent Document 2), differs from the actual time period of no gas use determined by the gas meter.

[0008] Therefore, in order to avoid a situation where the control device of a gas-powered power generation system determines that no gas leak has occurred even though the gas meter does not determine that the non-leakage conditions are met (i.e., no gas leak has occurred), it is preferable for the control device to determine that no gas leak has occurred when conditions stricter than the non-leakage conditions required by the gas meter are met (for example, the period of continuous non-use of gas is longer by a predetermined margin). However, setting such conditions means that the period required for the control device of the gas-powered power generation system to determine that the non-use conditions have been met will be longer. In other words, for example, the period during which power generation in the gas-powered power generation system is stopped in order to meet the non-use conditions will be longer, which means that the benefits for users of the gas-powered power generation system will be greatly diminished.

[0009] The present invention has been made in view of the above problems, and its objective is to provide a gas-consuming power generation system that can make a similar determination if the gas meter does not determine that the non-leakage conditions are met, while minimizing the time required for the control device of the gas-consuming power generation system to determine that the gas non-use conditions are met. [Means for solving the problem]

[0010] The characteristic configuration of the gas-consuming power generation system according to the present invention for achieving the above objective is a gas-consuming power generation unit that generates electricity by consuming fuel gas, an information output unit that can output information, and a control device, wherein the fuel gas supplied to the gas-consuming power generation unit is a supply gas supplied via a gas meter, or a gas obtained by modifying the supply gas supplied via the gas meter. The gas meter is configured to activate an alarm or shut off the supply of gas if the flow rate of the supplied gas remains below a first set determination amount for a set determination period or longer, or if the cumulative flow rate of the supplied gas during the set determination period remains below a second set determination amount, and the conditions for non-leakage do not occur a set number of times during the leak determination period. The control device is configured to perform a leak detection avoidance process, which includes a standby process, within a predetermined processing period of the same length as or shorter than the leak detection period, to transition to a standby state in which at least the amount of the supply gas supplied for power generation in the gas-consuming power generation unit is set to an amount that the gas meter determines satisfies the non-leak condition, and to continue the standby state, wherein the control device is configured to perform a leak detection avoidance process, which includes a standby process, The control device monitors the operating status of the gas consumption device that consumes the supplied gas supplied via the gas meter, The control device is configured to perform information output processing, which, if the predetermined gas non-use conditions are not met within the processing period, outputs information from the information output unit to the user indicating a high probability of the alarm being activated by the gas meter or the supply being shut off, or information encouraging the user to refrain from using the supplied gas. The control device determines that the gas no-use condition has been met when the cumulative number of reference periods, which are longer than or equal to the setting determination period, that are included in all consecutive periods of no gas use in which there is no or less than a predetermined amount of gas consumed by the gas consumption device during all the standby processes performed within the processing target period, reaches a target number equal to or greater than the setting number. The cumulative number of the reference period is derived by counting the number of reference periods included in the remaining period obtained by subtracting a predetermined margin period from each of the continuous gas non-use periods that occurred while the standby process was being performed, and accumulating the number of reference periods included in each of the continuous gas non-use periods. Here, the gas-consuming power generation unit may have a fuel cell unit having an anode to which the fuel gas is supplied and a cathode to which oxygen gas is supplied.

[0011] According to the above-described configuration, the control device is configured to perform information output processing, which outputs information from the information output unit to the user indicating that there is a high possibility of the gas meter activating an alarm or supply being shut off, or information encouraging the user to refrain from using the supplied gas, if the predetermined gas non-use conditions are not met within the processing period. As a result, the user can recognize that there is a high possibility of the gas meter activating an alarm or supply being shut off, or that they need to refrain from using the supplied gas.

[0012] Furthermore, if the gas meter experiences a set number of instances during the leak detection period in which the supply gas is not used for the set detection period, for example, it will not activate an alarm or shut off the supply gas. In this case, when the control device of the gas-consuming power generation system determines whether the gas no-use condition is met, it could calculate the cumulative number of reference periods included in the continuous gas no-use period without subtracting the margin period from that continuous gas no-use period. However, it deliberately calculates the cumulative number of reference periods included in the remaining period after subtracting the margin period from the continuous gas no-use period. Therefore, this feature configuration results in a smaller cumulative value of the number of reference periods included in each continuous gas no-use period compared to simply accumulating the number of reference periods included in the continuous gas no-use period without subtracting the margin period. In other words, if the gas meter does not determine that the non-leak condition is met, the control device of the gas-consuming power generation system is also more likely to not determine that the gas no-use condition, which is stricter than the non-leak condition, is met.

[0013] Furthermore, instead of setting a margin for each reference period included in the continuous gas-free period, the conditions are set so that one margin period is set for each continuous gas-free period. In other words, compared to the case where a margin is set for each reference period included in the continuous gas-free period, more reference periods can be counted in the continuous gas-free period. As a result, compared to the case where a margin period is set for each reference period included in the continuous gas-free period, the likelihood of the gas-free condition being met increases with a single continuous gas-free period that is shorter, or with multiple continuous gas-free periods that have a shorter total period. In other words, the time required for the control device of a gas-consuming power generation system to determine that the gas-free condition has been met is relatively short. Therefore, it is possible to provide a gas-consuming power generation system that minimizes the time required for the control device of the gas-consuming power generation system to determine that the gas non-use condition has been met, while also being able to make a similar determination if the gas meter does not determine that the non-leak condition has been met.

[0014] Another characteristic configuration of the gas-consuming power generation system according to the present invention is that, if the gas non-use condition is met while the leak detection avoidance process is being performed, the control device terminates the leak detection avoidance process and sets the amount of supplied gas supplied for power generation in the gas-consuming power generation unit to an amount that the gas meter determines does not satisfy the non-leak condition, thereby putting the gas-consuming power generation unit into a power generation state.

[0015] According to the above feature configuration, if the gas non-use condition is met while the leak detection avoidance process is running, the leak detection avoidance process is terminated, and the system is returned to a power generation state where power is generated by the gas-consuming power generation unit. In other words, if the period until the gas non-use condition is met, i.e., the period during which the leak detection avoidance process is performed, is short, the period until the power generation state where power is generated by the gas-consuming power generation unit is restarted will also be short, thus preventing a significant loss of benefits for users of the gas-consuming power generation system. In this feature configuration, for example, instead of having a margin for each standard period included in the continuous gas non-use period, the condition is set so that there is one margin period for each continuous gas non-use period. Therefore, compared to the case where a margin period is set for each standard period included in the continuous gas non-use period, the likelihood of the gas non-use condition being met in a single shorter continuous gas non-use period or multiple continuous gas non-use periods with a shorter total period is increased. As a result, the period during which the leak detection avoidance process is performed will not become too long, thus preventing a significant loss of benefits for users. [Brief explanation of the drawing]

[0016] [Figure 1] This is a diagram showing the configuration of a gas-powered power generation system. [Figure 2] This is a flowchart explaining the operation of the control device's leakage detection avoidance process. [Figure 3] This figure shows an example of a period of continuous gas non-use. [Figure 4] This figure shows another example of a continuous period of gas non-use. [Figure 5] This diagram illustrates the period of continuous gas non-use.

Best Mode for Carrying Out the Invention

[0017] Hereinafter, a gas consumption type power generation system S according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the configuration of a gas consumption type power generation system S. The gas consumption type power generation system S includes a fuel cell unit FC as a gas consumption type power generation unit that consumes fuel gas to generate electricity, an information output unit 28 capable of outputting information, and a control device 22. That is, the gas consumption type power generation unit of the present embodiment has a fuel cell unit FC having an anode 8 to which fuel gas is supplied and a cathode 9 to which oxygen gas is supplied.

[0018] The fuel gas supplied to the anode 8 is supply gas supplied via a gas meter 1, or gas obtained by reforming the supply gas supplied via the gas meter 1 in a reforming unit 7. For example, when the supply gas is a raw fuel gas such as city gas containing hydrocarbons, the raw fuel gas supplied via the gas meter 1 is supplied to the reforming unit 7. Although not shown, when the supply gas is hydrogen, hydrogen supplied via the gas meter 1 is supplied to the anode 8 as fuel gas without providing a reforming unit 7 or the like. In the following description, the case where the supply gas supplied from the gas meter 1 is a raw fuel gas such as city gas containing hydrocarbons will be described

[0019] The reforming unit 7 steam-reforms a raw fuel gas containing hydrocarbons such as city gas supplied via the gas meter 1 through a raw fuel gas flow path L1b (L1) to generate a reformed gas (fuel gas) containing hydrogen. The flow rate of the raw fuel gas received by the reforming unit 7 from the gas meter 1 per unit time is adjusted by a raw fuel flow rate adjusting unit 5. Then, the raw fuel gas whose flow rate has been adjusted by the raw fuel flow rate adjusting unit 5 is supplied to the reforming unit 7 via an adsorption unit 6.

[0020] Furthermore, water stored in the water tank 14 is supplied to the reforming section 7 via the water pump 16 and the water channel L10, and this water is used for steam reforming of the raw fuel gas. Although not shown in the diagram, a vaporizer may be provided to vaporize the supplied water. The operation of the raw fuel flow rate adjustment unit 5 is controlled by the control device 22.

[0021] The adsorption unit 6 is located upstream of the reforming unit 7 and includes an adsorbent 6a capable of adsorbing raw fuel gas and a temperature control unit 6b capable of adjusting the temperature of the adsorbent 6a. When the temperature of the adsorbent 6a is low, it adsorbs the raw fuel gas, and when the temperature is high, it desorbs the adsorbed raw fuel gas. Therefore, the control device 22 can adjust the temperature of the adsorbent 6a using the temperature control unit 6b, which is implemented using, for example, an electric heater, to desorb the raw fuel gas from the adsorbent 6a. For example, the adsorbent 6a can be made using activated carbon or zeolite, in which case the adsorbent 6a can be made to desorb the adsorbed raw fuel gas by raising its temperature to approximately 100°C to 200°C or higher. In addition, the adsorbent 6a may be made of, for example, silver zeolite, and may also be configured to serve as a desulfurizing agent for removing sulfur from city gas. The operation of the temperature control unit 6b is controlled by the control device 22.

[0022] The reformed gas generated in the reforming unit 7 is supplied to the fuel cell unit FC via the reformed gas flow path L2. Oxygen gas (air) is also supplied to the fuel cell unit FC via the air flow path L4. The flow rate per unit time of the air supplied to the cathode 9 of the fuel cell unit FC is regulated by the air flow rate control unit 15. The fuel cell unit FC has an anode 8 to which the reformed gas (fuel gas) generated in the reforming unit 7 is supplied, a cathode 9 to which oxygen gas is supplied, and an electrolyte layer 10 provided between them. For example, the electrolyte layer 10 is made using a solid oxide, in which case the fuel cell unit FC has a solid oxide type power generation cell. The operation of the airflow adjustment unit 15 is controlled by the control device 22.

[0023] The anode exhaust gas discharged from the anode 8 is supplied to the combustion section 11 via the anode exhaust gas flow path L3. The cathode exhaust gas discharged from the cathode 9 is supplied to the combustion section 11 via the cathode exhaust gas flow path L5. For example, the anode exhaust gas flow path L3 is an anode exhaust gas pipe through which the anode exhaust gas supplied from the anode 8 to the combustion section 11 flows. Also, for example, the cathode exhaust gas flow path L5 is a cathode exhaust gas pipe through which the cathode exhaust gas supplied from the cathode 9 to the combustion section 11 flows.

[0024] The combustion section 11 burns the combustion components contained in the anode exhaust gas discharged from the anode 8. The cathode exhaust gas discharged from the cathode 9 is also supplied to the combustion section 11, and the oxygen contained in this cathode exhaust gas is used for combustion. The heat of combustion generated in the combustion section 11 is then used for steam reforming of the raw fuel gas by the reforming section 7. Furthermore, if a vaporizer is provided to supply steam to the reforming section 7, the heat of combustion is supplied to the vaporizer and used for the vaporization of water.

[0025] The exhaust combustion gas discharged from the combustion section 11 is supplied to the heat exchanger 12 via the exhaust combustion gas flow path L6. Hot water flowing through the hot water circulation path L7 is also supplied to the heat exchanger 12. Heat exchange takes place between the exhaust combustion gas and the hot water in the heat exchanger 12. In this embodiment, this heat exchange cools the exhaust combustion gas and heats the hot water flowing through the hot water circulation path L7.

[0026] The hot water circulation path L7 circulates hot water between the hot water storage tank 17 and the heat exchanger 12. The hot water storage tank 17 stores hot water in a state where relatively low-temperature hot water is stored at the bottom and relatively high-temperature hot water is stored at the top, that is, in a state that forms a temperature stratification. Specifically, the hot water circulation path L7 consists of a forward path that transfers hot water from the hot water storage tank 17 to the heat exchanger 12 and a return path that transfers hot water from the heat exchanger 12 to the hot water storage tank 17, and has a circulation pump 18 installed in the middle of the forward path.

[0027] In this configuration, the hot water supplied from the bottom of the hot water storage tank 17 to the heat exchanger 12 via the forward path of the hot water circulation path L7 is heated in the heat exchanger 12, and the heated hot water is supplied to the top of the hot water storage tank 17 via the return path of the hot water circulation path L7. A temperature measuring unit 19 is provided in the middle of the return path to measure the temperature of the hot water being transferred from the heat exchanger 12 to the hot water storage tank 17. In this embodiment, the control device 22 controls the operation of the circulation pump 18 so that the temperature of the hot water flowing through the return path and into the hot water storage tank 17 (the temperature of the hot water measured by the temperature measuring unit 19) reaches a predetermined hot water storage target temperature (for example, 65°C). In this way, the hot water is stored, i.e., heat is accumulated, in a state where a temperature stratification is formed in the hot water storage tank 17.

[0028] A water supply channel L8a (L8) for supplying tap water to the hot water storage tank 17 is connected to the lower part of the hot water storage tank 17, and a hot water outlet channel L9 for discharging the hot water stored in the hot water storage tank 17 is connected to the upper part of the hot water storage tank 17. A water supply channel L8b (L8) is connected in the middle of the hot water outlet channel L9, allowing tap water to be mixed with the hot water discharged from the hot water storage tank 17. The amount of tap water mixed with the hot water discharged from the hot water storage tank 17 is controlled by a control valve 21 located in the middle of the water supply channel L8b. For example, the control device 22 controls the operation of the control valve 21 so that the temperature of the mixed hot water measured by the temperature measuring unit 20 reaches a predetermined temperature (for example, 30°C). The mixed hot water is then supplied to the user via the heat source device 4.

[0029] The heat source device 4 functions as a gas consumption device 2 that burns raw fuel gas supplied via the gas meter 1 and heats the hot water with the heat of combustion. For example, if the information receiving unit 23 receives a request from a user for 40°C hot water, the control device 22 heats the hot water to 40°C using the heat source device 4 and then supplies it to the user.

[0030] The exhaust combustion gas discharged from the combustion section 11 also contains water vapor. Therefore, when the exhaust combustion gas is cooled in the heat exchanger 12, the water vapor condenses. This condensed water then flows into the water recovery path L11. The recovered condensed water is supplied to the water tank 14 via the water purifier 13. The water purifier 13 is a device for removing impurities contained in the recovered condensed water. For example, the water purifier 13 is filled with ion exchange resin, and uses it to remove electrolyte ions (for example, ionized and dissolved salts and ammonia, etc.) contained in the recovered condensed water, for example, H + , OH - By replacing it with this, it performs the function of relatively lowering the concentration of electrolytes contained in the recovered condensed water (i.e., lowering the electrical conductivity).

[0031] The gas meter 1 is configured to activate an alarm or shut off the supply of raw fuel gas if the non-leak condition, which indicates that the flow rate of raw fuel gas is zero or low, does not occur a set number of times (e.g., 30 times) during the leak detection period (e.g., the past 30 days). For example, the gas meter 1 is configured to activate an alarm or shut off the supply of raw fuel gas if the non-leak condition, which indicates that the flow rate of raw fuel gas is less than or equal to the first set determination amount, is not met for a set number of times (e.g., 30 times) during the leak detection period, either for a set number of times (e.g., 30 times) or for a set number of times (e.g., 2 minutes) to be met, either for a set number of times or for a set number of times, or for a set number of times, that the cumulative flow rate of raw fuel gas during the set determination period (e.g., 2 minutes) is less than or equal to the second set determination amount.

[0032] The information storage unit 24 may store numerical values ​​such as the leak detection period, setting detection period, and setting count, which are referenced in the non-leakage conditions determined by the gas meter 1.

[0033] In the configuration illustrated in Figure 1, raw fuel gas is supplied from the gas meter 1 to the reforming unit 7 of the gas-consuming power generation system S via the raw fuel gas flow path L1b (L1), and raw fuel gas is supplied to the heat source device 4 of the gas-consuming power generation system S via the raw fuel gas flow path L1c (L1). The heat source device 4 is either a device provided by the gas-consuming power generation system S or a device attached to the gas-consuming power generation system S, and as will be described later, the control device 22 of the gas-consuming power generation system S can monitor the operating state of the heat source device 4 (i.e., the gas combustion operation). In addition, raw fuel gas is also supplied from the gas meter 1 to gas appliances 3, such as gas stoves and gas combustion fan heaters, via the raw fuel gas flow path L1a (L1). Therefore, the gas meter 1 determines, for example, whether a state satisfying the non-leakage condition has occurred with respect to the consumption of raw fuel gas in all of the reforming unit 7, the heat source device 4, and the gas appliances 3. Then, if the gas meter 1 finds that the conditions for no leakage have been met a set number of times during the leakage detection period, it determines that there is no abnormality and resets the timer for the leakage detection period to zero.

[0034] The control device 22 of the gas-consuming power generation system S performs a set timing to set the amount of raw fuel gas supplied for power generation in the fuel cell unit FC to an amount that the gas meter 1 determines to satisfy the non-leak condition, so that the gas meter 1 determines that the non-leak condition has been met a set number of times during the leakage determination period. Specifically, the control device 22 transitions to a standby state within a predetermined processing period (e.g., 27 days) that is the same length as or shorter than the leakage determination period (e.g., 30 days), and performs a leakage determination avoidance process that includes a standby process to continue the standby state, setting the amount of raw fuel gas supplied for power generation in the fuel cell unit FC to an amount that the gas meter 1 determines to satisfy the non-leak condition.

[0035] For example, during standby, the control device 22 stops the operation of the raw fuel flow rate adjustment unit 5, stopping the reforming unit 7 from receiving raw fuel gas from the gas meter 1, and stops the operation of the air flow rate adjustment unit 15, stopping the supply of air to the cathode 9. Furthermore, during standby, the control device 22 stops power generation, that is, it does not draw current from the fuel cell unit FC. However, during standby, the control device 22 may operate the water pump 16 to continue supplying water to the reforming unit 7.

[0036] Then, if the predetermined gas non-use conditions are not met within a predetermined processing period that is the same length as or shorter than the leak detection period, the control device 22 performs information output processing, outputting information from the information output unit 28 to the user indicating that there is a high possibility of alarm activation or supply shutoff by the gas meter 1, or information encouraging the user to refrain from using the raw fuel gas. For example, the information output unit 28 may be a device that can output voice information or text information (e.g., a remote control device), and such information may be communicated to the user via voice information or text information.

[0037] The control device 22 determines that the gas no-use condition has been met when the cumulative number of reference periods, which are longer than or equal to the set determination period (e.g., 2 minutes), and which are included in all consecutive periods of continuous gas no-use during which there is no or less than a set amount of raw fuel gas consumed by the heat source device 4 (gas consumption device 2) during all standby processing performed within the target processing period (e.g., 27 days), reaches a target number (e.g., 32 times) that is greater than or equal to the set number (e.g., 30 times). For example, the reference period may be set to the same length as the set determination period (e.g., 2 minutes).

[0038] The cumulative number of reference periods included in all continuous gas no-use periods is derived by counting the number of reference periods (e.g., 2 minutes) included in the remaining period after subtracting a predetermined margin period (e.g., 1 second to 300 seconds) from the continuous gas no-use period that occurred while standby processing was being performed, and then accumulating the number of reference periods included in each continuous gas no-use period.

[0039] The control device 22 can refer to values ​​for the reference period and margin period that have been received from the user by the information receiving unit 23 or values ​​that have been previously stored in the information storage unit 24.

[0040] Figure 2 is a flowchart illustrating the operation of the control device 22 regarding the leakage detection avoidance process. In process #10, the control device 22 determines whether it is time to start the leak detection avoidance process. Specifically, during the processing period, the control device 22 receives the raw fuel gas supply and operates the fuel cell unit FC to generate electricity when the leak detection avoidance process is not being performed. When it is time to start the leak detection avoidance process, the control device 22 proceeds to process #11 and starts the leak detection avoidance process.

[0041] For example, if the processing judgment period is 27 days, the control device 22 can determine that it is time to start the leak detection avoidance process when it is midnight on the 25th day of the processing judgment period. When it is midnight on the 25th day of the processing judgment period, the control device 22 transitions from the power generation state in which the fuel cell unit FC is generating power to a standby state (e.g., power generation stopped state) in which the amount of raw fuel gas supplied for power generation in the fuel cell unit FC is set to an amount that the gas meter 1 determines satisfies the non-leakage condition, and starts the leak detection avoidance process, which includes a standby process that continues in the standby state.

[0042] While the control device 22 is performing standby processing for leak detection avoidance processing, it monitors the operating status (i.e., gas combustion operation) of the heat source device 4, which acts as a gas consumption device 2 that consumes raw fuel gas supplied via the gas meter 1. For example, the gas combustor (not shown) provided in the heat source device 4 can send signals to the control device 22 indicating that gas combustion has stopped and signals indicating that gas combustion has started. This allows the control device 22 to understand not only the time periods when the fuel cell unit FC, which it controls, does not consume gas, but also the time periods when the heat source device 4 for hot water supply, which it does not control, does not consume gas.

[0043] However, there is a time lag between the timing when the control device 22 of the gas-consuming power generation system S receives a signal from the heat source device 4 for hot water supply indicating that gas combustion has stopped, and the actual timing when gas combustion stops in the heat source device 4 for hot water supply. Furthermore, there is a time lag between the timing when the control device 22 of the gas-consuming power generation system S receives a signal from the heat source device 4 for hot water supply indicating that gas combustion has started, and the actual timing when gas combustion starts in the heat source device 4 for hot water supply. In other words, the time period that the control device 22 of the gas-consuming power generation system S can grasp, which can be estimated to be when no gas is consumed in the fuel cell unit FC and no gas is consumed in the heat source device 4 for hot water supply, differs from the actual time period of no gas use determined by the gas meter 1. For this reason, the control device 22 independently determines whether predetermined gas no-use conditions have been met within the processing period, separate from the gas meter 1's determination of whether the non-leakage conditions have been met.

[0044] Figure 3 shows an example of a continuous gas non-use period that occurred during a standby period in which standby processing is being performed. As shown in the figure, the control device 22 performs standby processing during the processing period. The control device 22 then monitors the gas consumption status of the heat source device 4 and detects the occurrence of a continuous gas non-use period of the length shown in the figure. In this case, the control device 22 determines whether the gas non-use condition is met by the single continuous gas non-use period shown in Figure 3.

[0045] Furthermore, the length of continuous gas-free periods varies, and even if standby processing is performed to suppress gas consumption in the fuel cell unit (FC), if gas combustion occurs in the heat source device 4, the continuous gas-free period will be interrupted. Figure 4 shows another example of a continuous gas-free period that occurred during the standby period in which standby processing is performed. As shown in the figure, the control device 22 performs standby processing during the processing period. The control device 22 then monitors the gas consumption status in the heat source device 4 and detects the occurrence of multiple continuous gas-free periods of the length shown in the figure. In this case, the control device 22 determines whether the gas-free condition is met based on each continuous gas-free period shown in Figure 4.

[0046] Figure 5 illustrates a continuous gas no-use period. As shown in the figure, for each continuous gas no-use period that occurs while standby processing is being performed, the control device 22 counts the number of reference periods included in the remaining period obtained by subtracting a predetermined margin period from the continuous gas no-use period. In the example in Figure 5, one continuous gas no-use period contains four reference periods. In this way, the control device 22 derives the cumulative number of reference periods included in all continuous gas no-use periods by accumulating the number of reference periods included in each of the continuous gas no-use periods as shown in Figures 3 and 4.

[0047] In step #12, the control device 22 determines whether it is time to terminate the leak detection avoidance process. For example, the control device 22 determines that it is time to terminate the leak detection avoidance process if the above-mentioned gas non-use conditions are met. In other words, if the above-mentioned gas non-use conditions are not met, the control device 22 continues the standby process and continues to determine whether the gas non-use conditions are met during the standby period. In addition, to avoid the standby process continuing indefinitely, the control device 22 may determine that it is time to terminate the leak detection avoidance process when a predetermined period has elapsed (for example, when the processing target period has expired).

[0048] Then, if it is the end of the leak detection avoidance process, the control device 22 proceeds to process #13 and terminates the leak detection avoidance process. If the leak detection avoidance process is completed with the gas non-use condition met, the control device 22 terminates the standby process and sets the amount of raw fuel gas supplied for power generation in the fuel cell unit FC to an amount that the gas meter 1 determines does not meet the non-leak condition, thereby putting the fuel cell unit FC into a power generation state. On the other hand, if the leak detection avoidance process is completed because the processing period expires with the gas non-use condition not met, the control device 22 continues the standby process and performs information output processing, outputting information from the information output unit 28 to the user indicating a high possibility of alarm activation or supply shutoff by the gas meter 1, or information encouraging the user to refrain from using raw fuel gas.

[0049] <Another Embodiment> <1> In the above embodiment, the configuration of the gas-consuming power generation system S was specifically described, but its configuration can be modified as appropriate. For example, in the above embodiment, the case in which the gas-consuming power generation unit is a fuel cell unit FC was illustrated, but the gas-consuming power generation unit may have other configurations. For example, the gas-consuming power generation unit may have a configuration comprising a gas engine that operates using a supply gas (e.g., city gas, hydrogen, etc.) supplied via the gas meter 1, or a gas (e.g., hydrogen, etc.) obtained by reforming the supply gas (e.g., city gas, etc.) supplied via the gas meter 1 in the reforming unit 7, and a generator driven by the gas engine.

[0050] <2> In the above embodiment, an example was described in which the control device 22 determines that the leak detection avoidance process has ended when the above-mentioned gas non-use conditions are met. However, the conditions under which the control device 22 determines that the leak detection avoidance process has ended can be changed as appropriate. For example, the control device 22 may determine that the leak detection avoidance process has ended when the duration of the waiting process since the start of the leak detection avoidance process reaches a predetermined processing period. However, that single processing period must be at least the period calculated by the sum of the margin period and one base period. In other words, since it is expected that at least one base period will be included in the processing period of the waiting process, it is sufficient to perform such a waiting process multiple times.

[0051] <3> In the above embodiment, the control device 22 may, while performing standby processing, control the temperature of the adsorbent 6a using the temperature control unit 6b to desorb the raw fuel gas from the adsorbent 6a.

[0052] For example, during standby processing, the control device 22 may set the amount of raw fuel gas that the reforming unit 7 receives from the gas meter 1 to zero, that is, to a state where the gas meter 1 determines that the non-leakage condition is met, thereby stopping power generation in the fuel cell unit FC. During this time, the temperature control unit 6b may control the temperature of the adsorbent 6a to desorb the raw fuel gas from the adsorbent 6a. In this case, the raw fuel gas desorbed from the adsorbent 6a during standby processing diffuses to the anode 8 via the reforming unit 7. Therefore, during standby processing of the leak detection avoidance process, the intrusion of air or other external elements into the anode 8 is suppressed.

[0053] Alternatively, during standby, the control device 22 may use the temperature control unit 6b to control the temperature of the adsorbent 6a and use the raw fuel gas desorbed from the adsorbent 6a to generate reformed gas in the reforming unit 7 while simultaneously generating electricity in the fuel cell unit FC. In this case, during standby, the control device 22 sets the amount of raw fuel gas that the reforming unit 7 receives from the gas meter 1 to zero, that is, sets the gas meter 1 to a state where it determines that the non-leakage condition is met, and uses the temperature control unit 6b to control the temperature of the adsorbent 6a and use the raw fuel gas desorbed from the adsorbent 6a to generate reformed gas in the reforming unit 7 while simultaneously generating electricity in the fuel cell unit FC. The raw fuel gas desorbed from the adsorbent 6a diffuses and is supplied to the reforming unit 7, but if the reforming unit 7 has set the amount of raw fuel gas that it receives from the gas meter 1 to zero, the gas meter 1 will determine that the non-leakage condition is met. Furthermore, since the reforming unit 7 can generate reformed gas using the raw fuel gas desorbed from the adsorbent 6a, the control device 22 can extract current (generate power) from the fuel cell unit FC. However, this continued power generation during standby is an idling state in which the power generated by the fuel cell unit FC is supplied only to equipment necessary to operate the fuel cell unit FC, such as the water pump 16, circulation pump 18, raw fuel flow rate adjustment unit 5, air flow rate adjustment unit 15, control device 22, temperature control unit 6b, and power conditioner (not shown).

[0054] <4> In the above embodiment, an example was described in which the control device 22 sets the amount of raw fuel gas that the reforming unit 7 receives from the gas meter 1 to zero during standby processing (i.e., an example in which the gas meter 1 determines that the non-leakage condition is met). However, if the gas meter 1 determines that the non-leakage condition is met, the reforming unit 7 may receive raw fuel gas from the gas meter 1. Furthermore, during standby processing, the control device 22 may have the reforming unit 7 receive an amount of raw fuel gas from the gas meter 1 that the gas meter 1 determines to meet the non-leakage condition, and generate reformed gas while simultaneously generating electricity in the fuel cell unit FC.

[0055] In this case, during standby processing, the control device 22 receives a quantity of raw fuel gas from the gas meter 1 in the reforming unit 7 that the gas meter 1 determines satisfies the non-leakage condition. For example, as in the example above, if the gas meter 1 determines that the non-leakage condition is met when the flow rate of raw fuel gas is less than or equal to the first set determination amount for a period of time equal to or longer than the first set determination period, the control device 22 can, during this standby processing, control the operation of the raw fuel flow rate adjustment unit 5 to keep the flow rate of raw fuel gas to the reforming unit 7 less than or equal to the first set determination amount, and continue to allow the reforming unit 7 to receive raw fuel gas from the gas meter 1. Alternatively, if the gas meter 1 determines that a non-leak condition has been met, such as when the cumulative flow rate of raw fuel gas during the second setting determination period falls below the second setting determination amount, the control device 22 can, in this standby process, control the operation of the raw fuel flow rate adjustment unit 5 to keep the cumulative flow rate of raw fuel gas during the same period as the second setting determination period below the second setting determination amount, and continue to allow the reforming unit 7 to receive raw fuel gas from the gas meter 1. The reforming unit 7 can then generate reformed gas using the raw fuel gas received from the gas meter 1, and the control device 22 can then draw current from the fuel cell unit FC (generate power). However, the continued power generation performed in this standby process is the same idling power generation as described above.

[0056] Furthermore, during standby processing, the control device 22 may receive an amount of raw fuel gas from the gas meter 1 in the reforming unit 7 that the gas meter 1 determines satisfies the non-leakage condition, and use the raw fuel gas desorbed from the adsorbent 6a by adjusting the temperature of the adsorbent 6a by the temperature control unit 6b to generate reformed gas in the reforming unit 7 while generating electricity in the fuel cell unit FC.

[0057] <5> In the above embodiment, several numerical examples were described, but these values ​​are for illustrative purposes only and can be changed as appropriate.

[0058] <6> In the above embodiment, the case in which the heat source device 4 as the gas consumption device 2 is used for hot water supply to users was described. However, the heat source device 4 as the gas consumption device 2 may also be a heating heat source device 4 that heats a heat transfer medium supplied to, for example, a floor heating system and a bathroom heating and drying system.

[0059] <7> The configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Furthermore, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto and can be modified as appropriate without departing from the purpose of the present invention. [Industrial applicability]

[0060] The present invention can be used in a gas-consuming power generation system that minimizes the time required for the control device of the gas-consuming power generation system to determine that the gas non-use condition has been met, while also enabling the gas meter to make a similar determination if it does not determine that the non-leak condition has been met. [Explanation of Symbols]

[0061] 1: Gas meter 4: Heat source equipment (gas consumption equipment 2) 8: Anode 9: Cathode 22: Control device 28: Information output unit FC: Fuel cell section (gas-consuming power generation section) S: Gas-powered power generation system

Claims

1. The system comprises a gas-consuming power generation unit that generates electricity by consuming fuel gas, an information output unit that can output information, and a control device, wherein the fuel gas supplied to the gas-consuming power generation unit is either a supply gas supplied via a gas meter, or a gas obtained by modifying the supply gas supplied via the gas meter. The gas meter is configured to activate an alarm or shut off the supply of gas if the flow rate of the supplied gas remains below a first set determination amount for a set determination period or longer, or if the cumulative flow rate of the supplied gas during the set determination period remains below a second set determination amount, and the conditions for non-leakage do not occur a set number of times during the leak determination period. The control device is configured to perform a leak detection avoidance process, which includes a standby process, within a predetermined processing period of the same length as or shorter than the leak detection period, to transition to a standby state in which at least the amount of the supply gas supplied for power generation in the gas-consuming power generation unit is set to an amount that the gas meter determines satisfies the non-leak condition, and to continue the standby state, wherein the control device is configured to perform a leak detection avoidance process, which includes a standby process, The control device monitors the operating status of the gas consumption device that consumes the supplied gas supplied via the gas meter, The control device is configured to perform information output processing, which, if the predetermined gas non-use conditions are not met within the processing period, outputs information from the information output unit to the user indicating a high probability of the alarm being activated by the gas meter or the supply being shut off, or information encouraging the user to refrain from using the supplied gas. The control device determines that the gas no-use condition has been met when the cumulative number of reference periods, which are longer than or equal to the setting determination period, that are included in all consecutive periods of no gas use in which there is no or less than a predetermined amount of gas consumed by the gas consumption device during all the standby processes performed within the processing target period, reaches a target number equal to or greater than the setting number. A gas-consuming power generation system in which the cumulative number of the reference period is derived by counting the number of reference periods included in the remaining period obtained by subtracting a predetermined margin period from each of the continuous gas non-use periods that occurred while the standby process was being performed, and accumulating the number of reference periods included in each of the continuous gas non-use periods.

2. The gas-consuming power generation system according to claim 1, wherein if the gas non-use condition is met while the control device is performing the leak detection avoidance process, the control device terminates the leak detection avoidance process, and sets the amount of supplied gas supplied for power generation in the gas-consuming power generation unit to an amount that the gas meter determines does not satisfy the non-leak condition, thereby putting the gas-consuming power generation unit into a power generation state.

3. The gas-consuming power generation system according to claim 1 or 2, wherein the gas-consuming power generation unit has a fuel cell unit having an anode to which the fuel gas is supplied and a cathode to which oxygen gas is supplied.

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