JP2008218354A - Fuel cell power generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell power generation system capable of preventing propagation of legionella by evacuating only hot water having possibility of propagation of legionella outside a system. <P>SOLUTION: Part of water staying in a hot water tank 2 due to flow in tap water to that 2 is supplied through a water supply line 11 to a fuel cell power generation system 1. The fuel cell power generation system 1 warms the supplied water by exhaust heat from a fuel cell, and supplies it to an uppermost part of the hot water tank 2 through a hot water supply line 12. Here, an amount of warm water to be supplied to customers is measured by a flowmeter 4, and a control device 5 calculates an accumulated supply volume, that is, a hot-water usage volume, in a given time from the measured amount. Then, in case the hot-water usage volume supplied in the give time is judged to be less than the volume of the hot water tank 2, the control device 5 controls to open an exhaust valve 6 to evacuate water which has possibility of propagation of legionella in the hot water tank 2 remaining without being supplied to customers in the given time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell power generation system including a hot water storage tank that supplies hot water to consumers, and relates to a fuel cell power generation system capable of preventing the growth of Legionella in the hot water storage tank.

  In recent years, fuel cells have attracted attention as energy conversion devices with high power generation efficiency. The fuel cell power generation system converts the combined energy of hydrogen and oxygen generated by the fuel processor into electrical energy directly in the fuel cell body, and generates electricity with excellent pollutant emissions and low noise. Device.

  Here, a home fuel cell power generation system is usually configured by combining a fuel cell main body and a hot water storage tank for storing hot water generated in the fuel cell. This hot water tank generates hot water by absorbing waste heat due to a chemical reaction in the fuel cell body, and supplies it to consumers as needed, but the hot water remains in the hot water tank for a long time. If stored, Legionella bacteria may propagate in the hot water tank. As a result, there is a problem that hot water in a state in which Legionella is propagated is supplied to the consumer, and the health of the consumer using the hot water is impaired.

  Here, Legionella bacteria are a kind of common bacteria that inhabit the soil and water systems in the natural environment. These bacteria also exist in the human living environment and are detected from water-cooled coolers and humidifiers. The In addition, this Legionella bacterium may develop legionellosis if it ingests a large amount of the bacterium that has propagated but is not infectious and infects humans with weak immunity. The problem with Legionella disease is Legionella pneumonia, with the main symptoms being dullness, headache, fever and hemorrhoids, etc. It is clear that there is a high risk of danger to consumers.

Therefore, conventionally, as a countermeasure against reproduction of Legionella, an electric heater is installed in a supply line for supplying hot water generated by a fuel cell to a hot water tank as shown in Patent Document 1, and electric power is supplied to the electric heater. A method has been proposed in which hot water is heated to about 80 ° C. and the temperature of the hot water stored in the hot water tank is kept high (FIG. 9).
JP 2003-56909 A

  By the way, as described above, in a fuel cell power generation system for home use, a fuel cell power generation main body and a hot water storage tank are provided side by side, and hot water generated by using the reaction of the fuel cell main body is stored in a hot water storage tank for use by consumers. In this case, the supply format is common. In other words, the hot water supplied to the hot water tank stays inside until it is supplied to the consumer, and is generated by the fuel cell when the amount of hot water used by the consumer is relatively large, such as in winter. Although hot water stays for a short time, it stays in a hot water storage tank for a long time when the amount of hot water used is small, such as in summer.

  Here, in general, when hot water stays in a hot water tank at a temperature of about 40 ° C. for about 70 hours or longer, there is a high possibility that Legionella bacteria will propagate, and the usage amount of consumers such as in the summer When the amount of water is low, the hot water that Legionella is propagated will be supplied, affecting the health of consumers.

  Further, in the method of installing the electric heater on the supply line that supplies the hot water tank from the fuel cell as described above as the prior art, when the Legionella bacteria are likely to propagate, the electric heater is connected to the electric heater. Or the electric power was supplied from the fuel cell, and the warm water temperature was set to 80 degrees by heating the warm water, thereby suppressing the growth of Legionella bacteria.

  However, in the configuration shown above, since the total amount of hot water in the hot water tank is heated to a high temperature of 80 ° C. using an electric heater, a large amount of electric power is required, and the merit of the fuel cell power generation system having high power generation efficiency is greatly impaired. There was a possibility.

  The present invention has been proposed to solve the above-described problems, and by discharging only hot water with the possibility of breeding Legionella out of the system without supplying power to the electric heater. An object of the present invention is to provide a fuel cell power generation system capable of significantly reducing energy and economic loss and preventing the growth of Legionella bacteria.

  In order to achieve the above-described object, the present invention provides a fuel cell power generation system including a hot water tank that stores water supplied from a water source and hot water generated by supplying the water to the fuel cell. A flow meter for measuring the amount of hot water supplied from the hot water tank to the user, and a cumulative amount of hot water measured by the flow meter for a predetermined time are calculated, and the cumulative supply amount is calculated as a volume corresponding to the volume of the hot water tank. A control device that determines whether or not it exceeds, the control device being supplied to the user within the predetermined time when it is determined that the cumulative supply amount is less than the amount of water corresponding to the volume of the hot water tank. The water remaining in the hot water storage tank is discharged outside the system.

  The following points are also embodiments of the present invention. The hot water storage tank includes a thermometer for measuring the water temperature in the hot water storage tank, and the control device determines that the cumulative supply amount is less than the amount of water corresponding to the volume of the hot water storage tank within the predetermined time. Water which remains in the hot water tank without being supplied to the user and whose water temperature measured by the thermometer is equal to or higher than a predetermined temperature is discharged out of the system.

  A plurality of the thermometers are installed in the vertical direction with respect to the hot water storage tank, and the control device calculates a temperature boundary layer between water and hot water generated by the fuel cell from the plurality of thermometers installed. When the cumulative supply amount is determined to be less than the amount of water corresponding to the volume of the hot water tank, the water in the vicinity of the temperature boundary layer remaining in the hot water tank without being supplied to the user within the predetermined time is removed from the system. It is characterized by discharging.

  A water flow meter for measuring a flow rate of water supplied from the water source to the hot water storage tank; the control device calculates a cumulative flow rate of water measured by the water flow meter for a predetermined time; When it is determined that the flow rate is less than the amount of water corresponding to the volume of the hot water tank, water remaining in the hot water tank without being supplied to the user within the predetermined time is discharged outside the system. The invention encompasses.

  According to the present invention as described above, the hot water staying in the hot water storage tank can be discharged out of the system for a time longer than the time when Legionella bacteria can propagate without using an electric heater. It is possible to provide a fuel cell power generation system that can reduce consumption and prevent the growth of Legionella bacteria while maintaining the high power generation efficiency that is the original effect of the fuel cell.

[First embodiment]
[Constitution]
FIG. 1 shows a fuel cell power generation system according to a first embodiment to which the present invention is applied. Although the configuration of the present embodiment will be described in detail below, the present invention has features in the hot water storage tank and its surroundings, and thus detailed configurations such as a general fuel cell main body and a reformer are omitted.

  As shown in FIG. 1, the present invention includes a fuel cell power generation device 1, a hot water storage tank 2 that supplies water to the fuel cell power generation device 1 and stores hot water that has become hot water, and a temperature at which the temperature in the hot water storage tank is measured. It consists of a total 3 and a flow meter 4 that measures the amount of hot water supplied from the hot water tank 2 to consumers. Furthermore, the control device 5 for adjusting whether or not the water in the hot water tank 2 is discharged out of the system based on the water temperature measured by the thermometer 3 or the usage amount of the hot water measured by the flow meter 4, and the control A discharge valve 6 that opens and closes the discharge line when the apparatus 5 determines that the water in the hot water tank 2 is discharged is also provided.

  In addition, a tap water supply line 10 for supplying tap water to the hot water tank 2 is connected to the lower part of the hot water tank 2, and tap water supplied to the hot water tank 2 flows into the hot water tank 2 to generate hot water. A water supply line 11 is connected to the fuel cell power generator 1 from the lower part of the hot water tank 2. Further, a hot water supply line 12 is attached from the fuel cell power generator 1 to the upper part of the hot water tank 2 so that the hot water generated by the fuel cell power generator 1 is supplied to the hot water tank 2. The hot water tank 2 is also provided with a consumer supply line 13 for supplying hot water to the consumer from the hot water tank 2 and a discharge line 14 for discharging hot water that has been retained for a predetermined time or more by the control device 5 as will be described later.

  Here, the fuel cell power generation device 1 includes a fuel cell main body, a heat exchanger, and the like. The water supplied from the hot water storage tank 2 generates hot water using waste heat from a chemical reaction in the fuel cell main body, and again. The hot water tank 2 is supplied. Specifically, water from the hot water tank 2 is supplied to the fuel cell power generation device 1 through the water supply line 11, and the fuel cell power generation device 1 absorbs the exhaust heat from the fuel cell main body, Generate. Then, the hot water is supplied to the upper part of the hot water tank 2 through the hot water supply line 12. Thereby, the hot water for supplying to a consumer as needed is stored in the hot water tank 2.

  The hot water storage tank 2 is supplied with tap water and stores hot water generated by supplying the tap water to the fuel cell power generation device 1, but the volume of hot water that can be stored is determined. And the thermometer 3 attached to the hot water tank 2 measures the temperature of the water staying in the hot water tank 2, and plays an important role in judging whether the temperature of Legionella is easy to propagate. I'm in charge.

  As described above, the flow meter 4 measures the amount of hot water supplied from the hot water tank 2 to the consumer, and until the Legionella bacteria propagate based on the residence time of the hot water stored in the hot water tank 2. It is also important for measuring the supply flow rate within a predetermined time (for example, about 70 hours with 40 ° C. warm water). The flow meter 4 is attached to a consumer supply line 13 that supplies hot water from the hot water tank 2 to the consumer.

  The control device 5 detects the flow rate supplied to the consumer of the hot water staying in the hot water tank 2 through the flow meter 4, and calculates the cumulative supply amount in a predetermined time until the Legionella bacteria propagate. The volume of water previously stored in the hot water tank 2 (assuming that the water in the hot water tank 2 is full), the volume of the hot water tank 2. Hereinafter, the volume of the hot water tank 2 .)). In addition, when the control device 5 determines that the accumulated supply amount to the consumer in a predetermined time is smaller than the volume amount of the hot water tank 2, the Legionella bacterium is caused by the remaining hot water that is not supplied even after the predetermined time has elapsed. Therefore, the water in the hot water tank 2 remaining for a predetermined time or more is controlled to be discharged through the discharge valve 6.

  That is, this control device 5 calculates the cumulative supply flow rate of hot water within a predetermined time, and whether or not the supply flow rate is larger than the amount of water stored from a predetermined time before, here the amount of water corresponding to the volume of the hot water tank 2. Therefore, when there is less water than the volume, water with the possibility of breeding Legionella remains, so that such water is discharged. Specifically, when it is determined that the accumulated supply amount within a predetermined time is smaller than the volume amount of the hot water tank 2, the control device 5 issues a command to open the discharge valve 6, and the predetermined time is set through the discharge line 14. Drain the elapsed water.

  Moreover, the said control apparatus 5 discharges | emits the water which the temperature measured with the thermometer 3 installed in the hot water tank 2 upper part is about tap water temperature so that it may not discharge | emit more than necessary water at the time of discharge | emission. Control as follows. In other words, the stored water having a temperature at which Legionella is not likely to propagate is controlled to be excluded when discharged. Note that the control device 5 performs control so that the discharge valve 6 is closed when the accumulated supply amount in a predetermined time is larger than the volume amount of the hot water tank 2 or when the water remaining for the predetermined time or more is discharged.

  The discharge valve 6 is installed in the discharge line 14 and opens and closes based on the determination of the control device 5 as described above. Specifically, the discharge valve 6 is opened when the control device 5 determines that the cumulative supply amount in a predetermined time is less than the volume amount of the hot water tank 2, and the discharge valve is determined when it is determined that the amount is greater than the volume amount. 6 is maintaining the state where it was plugged.

[Action]
The operation of the present embodiment having the above-described configuration is as follows.
First, when a consumer uses hot water, tap water flows into the hot water tank 2 through the tap water supply line 10, and the tap water is stored from the bottom of the hot water tank 2. A part of the lowermost water accumulated in the hot water tank 2 flows into the fuel cell power generator 1 through the water supply line 11. The water flowing into the fuel cell power generation device 1 becomes hot water by absorbing exhaust heat from the fuel cell, and is supplied to the uppermost portion of the hot water tank 2 through the hot water supply line 12.

  Here, the flow rate of the hot water supplied to the consumer is measured by the flow meter 4, and the control device 5 calculates the accumulated supply amount in a predetermined time, that is, the hot water supply usage amount, from the measured flow rate. When the controller 5 determines that the amount of hot water supply supplied within a predetermined time is less than the volume of the hot water storage tank 2, the controller 5 supplies the consumer within a predetermined time because there is a possibility of Legionella bacteria breeding. In order to discharge the remaining water in the hot water tank 2 without being discharged, the discharge valve 6 is controlled to be opened. As a result, the discharge valve 6 is opened, and the water in the hot water storage tank 2 remaining for a predetermined time or more is discharged through the discharge line 14.

  In order to prevent excessive discharge of water when discharging, the control device 5 has a temperature measured by the thermometer 3 installed on the upper part of the hot water tank 2 at a predetermined temperature (for example, about the temperature of tap water). ) The above water is controlled to be discharged, and water up to the temperature is discharged through the discharge line 14. That is, the control device 5 performs control so that water that remains without being supplied to the consumer within a predetermined time and whose temperature measured by the thermometer 3 is equal to or higher than the predetermined temperature is discharged out of the system. When the water remaining above the predetermined temperature and remaining for the predetermined time (in this case, the volume in the hot water tank 2 -the integrated hot water supply amount) is discharged, the control device 5 shuts off the discharge line 14. The discharge valve 6 is closed.

[effect]
In the present embodiment having the above-described configuration, the hot water tank 2 is heated by an electric heater or a boiler by discharging hot water staying in the hot water tank 2 for a time longer than the time when Legionella can grow. Thus, it is possible to provide a fuel cell power generation system capable of suppressing the growth of Legionella bacteria without performing the above process. Therefore, power consumption due to the use of a battery heater or boiler can be reduced, and the proliferation of Legionella can be prevented while maintaining high power generation efficiency, which is the original effect of the fuel cell.

[Second Embodiment]
[Constitution]
FIG. 2 shows a fuel cell power generation system according to a second embodiment to which the present invention is applied, in which the peripheral configuration of the hot water tank 2 of the first embodiment is partially changed. In addition, although the structure of this embodiment is explained in full detail below, the same code | symbol is attached | subjected to the component similar to said 1st Embodiment, and description is abbreviate | omitted.

  First, as shown in FIG. 2, the present invention includes a fuel cell main body 1, a hot water tank 2, and a flow meter 4 having the same configuration as in FIG. 1. Here, the feature point of the configuration of the present embodiment is that a plurality of thermometers 3a to 3d and discharge lines 14a to 14d are installed in the hot water storage tank 2, and a plurality of discharge valves 6a to 6d are respectively connected to the discharge lines 14a to 14d. 6d is attached. Whether or not the control device 5 discharges the water in the hot water tank 2 out of the system based on the water temperature measured by the plurality of thermometers 3 a to 3 d and the supply amount of the hot water measured by the flow meter 4. It is also a point which is different from 1st Embodiment also to control through several discharge valve 6a-6d.

  Specifically, the plurality of thermometers 3 a to 3 d of the present embodiment are installed in the vertical direction of the hot water tank 2 (here, four), and the temperature of the water accumulated in the hot water tank 2 is strictly determined. It is possible to measure. In addition, as shown in FIG. 2, discharge lines 14 a to 14 d are installed in the hot water storage tank 2 at positions corresponding to the plurality of thermometers 3 a to 3 d, for example, in the vicinity of the thermometers or on parallel lines. The water around the measured temperature is discharged through each discharge line. In addition, each discharge valve is installed in each discharge line in order to control supply / blocking of discharged water.

  Here, the discharge line 14a is installed at the position of the hot water tank 2 parallel to the thermometer 3a, the discharge valve 6a is mounted on the discharge line 14a, and the other thermometers 3b to 3d installed in the vertical direction. Similarly, discharge lines 14b to 14d and discharge valves 6b to 6d are installed.

  In addition, the control apparatus 5 calculates the cumulative supply amount of the hot water to the consumer in a predetermined time via the flow meter 4 and determines whether or not the supply amount is larger than the volume amount of the hot water tank 2. Although it is the same as that of 1st Embodiment, in addition to this, the position of the temperature boundary layer mentioned later is calculated based on the water temperature measured by several thermometer 3a-3d. The temperature boundary layer is a temperature boundary surface between tap water supplied to the hot water tank 2 and hot water generated by the fuel cell power generator 1 and supplied to the hot water tank 2.

  That is, based on the calculated temperature boundary layer, the control device 5 performs control so that water near the temperature boundary layer is discharged through a discharge valve and a discharge line installed at a close position. Specifically, the temperature calculated based on the water temperature measured by the plurality of thermometers 3a to 3d when it is determined that the accumulated supply amount to the consumer, that is, the hot water supply usage amount is smaller than the volume amount of the hot water tank 2 Control to drain water near the boundary layer. That is, control is performed so that the discharge valve installed near the temperature boundary layer is opened and discharged to the outside of the system through the discharge line.

[Action]
The operation of the present embodiment having the above-described configuration is as follows.
First, as in the first embodiment, when a consumer uses hot water, tap water flows into the hot water tank 2 through the tap water supply line 10, and tap water is stored from the bottom of the hot water tank 2. A part of the lower water flows into the fuel cell power generator 1 through the water supply line 11. The water flowing into the fuel cell power generation device 1 becomes hot water by absorbing exhaust heat from the fuel cell, and is supplied to the uppermost portion of the hot water tank 2 through the hot water supply line 12.

  Here, the heated hot water flowing into the hot water tank 2 and the water accumulated in the hot water tank 2 are not mixed, and the hot water heated in the vertical direction and the accumulated tap water exist separately. It becomes the temperature boundary layer 7. That is, it can be determined that the water staying in the vicinity of the temperature boundary layer 7 is the tap water that first flows into the hot water tank 2.

  And the control apparatus 5 calculates the cumulative supply amount to a consumer in a predetermined time, that is, the hot water supply usage amount through the flow meter 4, and the hot water supply usage amount within the predetermined time is less than the volume amount of the hot water tank 2. In such a case, water remaining without being supplied to the consumer for a predetermined time or longer (in this case, the volume in the hot water tank 2 minus the accumulated hot water usage amount) is discharged.

  Here, in the present invention, the control device 5 calculates the vertical position of the temperature boundary layer 7 described above based on the water temperatures measured by the plurality of thermometers 3, and the hot water storage tank from the discharge valve near the temperature boundary layer 7. The water in 2 is controlled to be discharged through a discharge line in which the discharge valve is installed. As a result, the discharge valve close to the temperature boundary layer is opened, and only the water retained for a predetermined time or more is discharged without discharging the hot water in the upper part of the hot water tank 2 accumulated so far.

  For example, in FIG. 3, since the temperature boundary layer 7 is formed in the vicinity of the thermometer 3c, the discharge valve 6c installed on a line parallel to the thermometer 3c is opened through the control device 5 and discharged. Water remaining without being supplied to the consumer for a predetermined time or longer is discharged through the line 14c.

[effect]
The present embodiment having the above-described configuration is similar to the first embodiment in that only hot water staying in the hot water storage tank 2 is discharged out of the system for a time longer than the time when Legionella bacteria may propagate. It is possible to provide a fuel cell power generation system capable of suppressing the growth of Legionella bacteria without heating the hot water tank 2 with a heater or a boiler.

  Moreover, since the temperature boundary layer 7 can be obtained by providing a plurality of thermometers, discharge valves, and discharge lines in the hot water tank 2 in the vertical direction, the accumulated heat is stored in the hot water tank 2 for a long time without wasting it. It becomes possible to discharge water. Therefore, Legionella bacteria do not propagate in the hot water tank 2, and safer hot water can be supplied to consumers.

[Third embodiment]
[Constitution]
4 and 5 show a fuel cell power generation system according to a third embodiment to which the present invention is applied, in which the peripheral configuration of the hot water tank 2 of the first and second embodiments is partially changed. It is. In addition, although the structure of this embodiment is explained in full detail below, the same code | symbol shall be attached | subjected to the component similar to said 1st Embodiment, and description is abbreviate | omitted.

  Specifically, in this configuration, the flow meter 4 installed in the consumer supply line 13 above the hot water tank 2 in the first embodiment is connected to the lower part of the hot water tank 2 as shown in FIG. It is characterized in that it is installed in the tap water supply line 10. In FIG. 5, the flow meter 4 installed in the consumer supply line 13 above the hot water tank 2 in the second embodiment is installed in the tap water supply line 10 connected to the lower part of the hot water tank 2. Yes.

  That is, as shown in FIGS. 4 and 5, the flow rate of the supplied tap water is measured by attaching the flow meter 4 to the tap water supply line 10 that supplies the tap water to the hot water tank 2. That is, when a consumer uses hot water, the amount discharged as the hot water use flows into the hot water tank 2 through the tap water supply line 10, and the supply amount of tap water measured by the flow meter 4 here. Can be regarded as a flow rate of supplying hot water to the consumer through the consumer supply line 13.

  Therefore, the control device 5 calculates the accumulated flow rate of tap water within a predetermined time through the flow meter 4 installed in the tap water supply line 10, and whether or not this accumulated flow rate is smaller than the volume amount of the hot water tank 2. Judging. In the example of FIG. 4, when the cumulative flow rate of tap water within a predetermined time is smaller than the volume of the hot water tank 2, the control device 5 has water that is not supplied even after the predetermined time has passed. It is determined that there is a possibility of breeding Legionella bacteria, and the water in the hot water tank 2 remaining without being supplied to the consumer for a predetermined time or more is controlled to be discharged through the discharge valve 6.

  Further, in the example of FIG. 5, when the accumulated flow rate of tap water within a predetermined time is smaller than the volume of the hot water tank 2, the control device 5 measures the water temperature measured by the plurality of thermometers 3 a to 3 d. Control to discharge water near the temperature boundary layer calculated based on That is, control is performed so that the discharge valve installed near the temperature boundary layer is opened and discharged to the outside of the system through the discharge line.

[Action]
The operation of the present embodiment having the above-described configuration is as follows.
In the example of FIG. 4, first, when a consumer uses hot water, tap water flows into the hot water tank 2, and thus the flow rate is measured by the flow meter 4 installed in the tap water supply line 10. And tap water is stored from the lowermost part of the hot water tank 2, and a part of the lowermost water flows into the fuel cell power generator 1 through the water supply line 11. Thus, the water that flows in by absorbing the exhaust heat from the fuel cell main body becomes warm water, and is supplied to the hot water tank 2 through the warm water supply line 12.

  Here, the control device 5 calculates the accumulated flow rate for a predetermined time from the flow rate of tap water measured by the flow meter 4. And the control apparatus 5 judges that there is possibility of reproduction of Legionella bacteria when the accumulated flow volume of the tap water in a predetermined time is smaller than the volume amount of the hot water tank 2, and is not supplied to the consumer for a predetermined time or more. In order to discharge the water in the hot water tank 2 remaining in the tank, the discharge valve 6 is controlled to be opened. As a result, the discharge valve 6 is opened, and the water in the hot water storage tank 2 remaining for a predetermined time or more is discharged through the discharge line 14.

  Moreover, the control device 5 has a predetermined temperature (for example, about the temperature of tap water) or more based on the thermometer 3 installed in the upper part of the hot water tank 2 so that excessive water is not discharged when discharging. Control is performed to discharge water that has remained for a predetermined time or more.

  In the example of FIG. 5, as in FIG. 4, when a customer uses hot water, tap water flows into the hot water storage tank 2, so the flow rate is measured by the flow meter 4 installed in the tap water supply line 10. The And tap water is stored from the lowermost part of the hot water tank 2, and a part of the lowermost water flows into the fuel cell power generator 1 through the water supply line 11. Thereby, the tap water becomes hot water by absorbing the exhaust heat from the fuel cell main body, and is supplied to the hot water tank 2 through the hot water supply line 12.

  Here, the control device 5 calculates a cumulative flow rate for a predetermined time based on the flow rate of tap water measured by the flow meter 4, and if the cumulative flow rate is less than the volume of the hot water tank 2, the demand is greater than the predetermined time. The remaining water is discharged without being supplied to the person. When discharging the water remaining for the predetermined time or more, the control device 5 calculates the vertical position of the temperature boundary layer 7 from the plurality of thermometers 3 and the inside of the hot water tank 2 from the discharge valve in the vicinity of the temperature boundary layer 7. Control to discharge water through the discharge line where the discharge valve is installed. As a result, the discharge valve close to the temperature boundary layer 7 is opened, and only the water staying over a predetermined time is discharged without discharging the hot water in the upper part of the hot water tank 2 accumulated so far.

[effect]
In the present embodiment having the above configuration, the flow rate of tap water is measured by the flow meter 4 installed in the tap water supply line 10 without actually measuring the supply amount of hot water to the consumer, Based on this, it is possible to discharge the hot water retained in the hot water storage tank 2 where Legionella bacteria can breed. For this reason, as in the first and second embodiments, the interior of the hot water tank 2 is not heated by an electric heater or boiler, so that power consumption can be reduced, while maintaining the high power generation efficiency that is the original effect of the fuel cell while maintaining Legionella bacteria. A fuel cell power generation system capable of suppressing breeding can be provided.

[Other Embodiments]
In addition, this invention is not limited to the above embodiments, The display apparatus 8 for encouraging a consumer to use hot water supply to the control apparatus 5 in said 1st-3rd embodiment is mentioned. Embodiments having an installed configuration are also included. In other words, the display device 8 has a function of performing a display for prompting the consumer to use hot water supply when the control device 5 determines that Legionella is capable of breeding. Note that the display device 8 is not limited to a display for visually recognizing by a consumer, and may prompt the use of hot water by voice.

  A specific operation will be described with reference to FIG. 6, taking as an example the case where the display device 8 is installed in the first embodiment. First, when a consumer uses hot water, tap water flows into the hot water tank 2 through the tap water supply line 10, the tap water is stored from the lowermost part of the hot water tank 2, and a part of the lowermost water is fuel. It flows into the battery power generator 1 through the water supply line 11. The water flowing into the fuel cell power generation device 1 becomes hot water by absorbing exhaust heat from the fuel cell, and is supplied to the uppermost portion of the hot water tank 2 through the hot water supply line 12.

  Here, the supply amount of the hot water supplied to the consumer is measured by the flow meter 4, and the control device 5 calculates the cumulative supply amount, that is, the hot water supply usage amount for a predetermined time, from the measured supply amount. Then, the control device 5 performs control so that a display prompting the user to use hot water is displayed via the display device 8 when it is determined that the amount of hot water supply supplied within a predetermined time is less than the volume of the hot water tank 2. To do.

  For this reason, the hot water accumulated in the hot water tank 2 is displayed on the display device 8 within a time during which Legionella bacteria may propagate, so that hot water is used less in the hot water tank 2 for a long time. Even in this case, it is possible to prevent the proliferation of Legionella bacteria. 7 and 8 show a configuration diagram in which the display device 8 is provided in the second and third embodiments (third embodiment based on the first embodiment).

Configuration diagram of the first embodiment of the present invention Configuration of the second embodiment of the present invention (1) Configuration diagram (2) of the second embodiment of the present invention Configuration of the third embodiment of the present invention (1) Configuration of the third embodiment of the present invention (2) Configuration diagram showing another embodiment of the present invention (1) Configuration (2) showing another embodiment of the present invention Configuration (3) showing another embodiment of the present invention The block diagram which shows the prior art of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell power generation device 2 ... Hot water storage tank 3 ... Thermometer 3a-3d ... Thermometer 4 ... Flow meter 5 ... Control device 6 ... Drain valve 6a-6d ... Drain valve 7 ... Temperature boundary layer 8 ... Display apparatus 10 ... Water supply Water supply line 11 ... Water supply line 12 ... Hot water supply line 13 ... Consumer supply line 14 ... Discharge lines 14a to 14d ... Discharge line

Claims (11)

In a fuel cell power generation system including a hot water storage tank that stores water supplied from a water source and hot water generated by supplying the water to the fuel cell,
A flow meter for measuring the amount of hot water supplied from the hot water tank to the user;
A controller for calculating a cumulative supply amount of hot water measured by the flow meter at a predetermined time, and determining whether the cumulative supply amount exceeds a water amount corresponding to a volume amount of the hot water tank;
When it is determined that the cumulative supply amount is less than the volume of water corresponding to the volume of the hot water tank, the control device discharges water remaining in the hot water tank without being supplied to the user within the predetermined time. A fuel cell power generation system. The hot water tank is equipped with a thermometer for measuring the water temperature in the hot water tank,
When it is determined that the cumulative supply amount is less than the volume of water corresponding to the volume of the hot water tank, the control device remains in the hot water tank without being supplied to the user within the predetermined time and is measured by the thermometer. 2. The fuel cell power generation system according to claim 1, wherein water having a water temperature equal to or higher than a predetermined temperature is discharged out of the system. A plurality of the thermometers are installed in the vertical direction with respect to the hot water tank,
The control device calculates a temperature boundary layer between water and hot water generated by the fuel cell from a plurality of the thermometers installed, and determines that the cumulative supply amount is less than the water amount corresponding to the volume amount of the hot water tank. 3. The fuel cell power generation system according to claim 2, wherein, in the case where the temperature boundary layer is not supplied to the user within the predetermined time, the water in the vicinity of the temperature boundary layer is discharged out of the system. A discharge line for discharging water remaining in the hot water tank without being supplied to the user within the predetermined time in the vicinity of each of the plurality of thermometers installed,
4. The fuel cell power generation system according to claim 3, wherein the control device discharges water remaining in the hot water storage tank without being supplied to the user within the predetermined time from the discharge line near the temperature boundary layer. . A water flow meter for measuring the flow rate of water supplied from the water source to the hot water tank,
The control device calculates a cumulative flow rate of water measured by the water flow meter for a predetermined time, and determines that the cumulative flow rate is less than a water amount corresponding to the volume of the hot water tank. The fuel cell power generation system according to any one of claims 1 to 4, wherein water remaining in the hot water tank without being supplied to the user is discharged out of the system. A display device for displaying information;
The control device calculates a cumulative supply amount of water measured by the flow meter at a predetermined time, or calculates a cumulative flow rate of water measured by the water flow meter at a predetermined time,
When it is determined that one of the calculated cumulative supply amount and the cumulative flow rate is less than the amount of water corresponding to the volume of the hot water tank, supply to the user via the display device within the predetermined time The fuel cell power generation system according to any one of claims 1 to 5, wherein information that promotes utilization of water remaining in the hot water tank without being transmitted is transmitted.   The fuel cell power generation system according to claim 6, wherein the display device transmits information by voice. In a control method of a fuel cell power generation system including a hot water storage tank that stores water supplied from a water source and hot water generated by supplying the water to the fuel cell,
A flow meter for measuring the amount of hot water supplied to the user from the hot water tank,
Calculate a cumulative supply amount of hot water measured by the flow meter for a predetermined time, and execute a control step of determining whether the cumulative supply amount exceeds a water amount corresponding to the volume amount of the hot water tank,
In the control step, when it is determined that the accumulated supply amount is less than the volume of water corresponding to the volume of the hot water tank, the water remaining in the hot water tank without being supplied to the user within the predetermined time is discharged out of the system. A control method for a fuel cell power generation system. The hot water tank is equipped with a thermometer for measuring the water temperature in the hot water tank,
In the control step, when it is determined that the accumulated supply amount is less than the amount of water corresponding to the volume of the hot water tank, it remains in the hot water tank without being supplied to the user within the predetermined time and is measured by the thermometer. 9. The method of controlling a fuel cell power generation system according to claim 8, wherein water having a water temperature of a predetermined temperature or more is discharged outside the system. A plurality of the thermometers are installed in the vertical direction with respect to the hot water tank,
The control step calculates a temperature boundary layer between water and hot water generated by the fuel cell from a plurality of the thermometers installed, and determines that the cumulative supply amount is less than the water amount corresponding to the volume amount of the hot water tank. 10. The control of the fuel cell power generation system according to claim 9, wherein water in the vicinity of the temperature boundary layer that is not supplied to the user within the predetermined time and remains in the hot water storage tank is discharged out of the system. Method. A water flow meter for measuring the flow rate of water supplied from the water source to the hot water tank,
The control step calculates a cumulative flow rate of the water measured by the water flow meter for a predetermined time, and determines that the cumulative flow rate is less than a water amount corresponding to the volume of the hot water tank. The method for controlling a fuel cell power generation system according to any one of claims 8 to 10, wherein water remaining in the hot water storage tank without being supplied to a user is discharged out of the system.

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