JP2008177052A - Domestic fuel cell system, and exhaust heat distribution unit used for it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a domestic fuel cell system which performs utilization of exhaust heat simply and positively even in summer time with little demand for hot water and is capable of implementing a cogeneration operation with high all-round energy efficiency, and is superior in energy-saving and economy. <P>SOLUTION: An exhaust heat distribution unit 200 installed separately from a fuel cell system main body package 100 stores exhaust heat from the main body package 100 to a hot water tank 201 and distributes hot water stored respectively and individually to a hot water supply unit 300, air-conditioner 400, washing machine 500, dish washer 600, and toilet facility 700 through a plurality of distribution valves 211-215. A control part 221 of the exhaust heat distribution 200 determines a priority order of hot water distribution to the exhaust heat utilization equipment and controls the distribution valves 211-215, and an operation display part 222 obtains a condition instruction on the priority order of the hot water distribution from a user, and displays visually information on the priority order of hot water distribution. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a household fuel cell system including a fuel cell that generates electricity by an electrochemical reaction using a fuel and an oxidant, and more particularly to a technique for effectively using the exhaust heat. .

  A polymer electrolyte fuel cell is formed by laminating a plurality of structures in which battery cells are sandwiched by separators, with the anode side electrode serving as the fuel electrode and the cathode side electrode serving as the oxidant electrode facing each other across the polymer electrolyte membrane. Configured.

  In such a polymer electrolyte fuel cell, since mobility is regarded as important for in-vehicle use or the like, usually, there are many systems using pure hydrogen as a fuel and air as an oxidant. However, for stationary and household use, a system that uses city gas or propane gas with a high methane component as fuel is required due to infrastructure problems. In this case, in order to reform the fuel into hydrogen, a method using a fuel processor that generates hydrogen by mixing water vapor with the fuel is generally used.

  In either system, hydrogen supplied to the anode electrode is ionized and flows through the solid polymer electrolyte membrane to react with oxygen on the cathode electrode side, generating water and obtaining electrical energy to the outside. It is done.

  By the way, this polymer electrolyte fuel cell generates exhaust heat of about 100 ° C. or less with generation of electric energy. This is because, as long as the battery efficiency does not reach 100%, that is, unless power generation becomes possible with the battery body temperature at the ambient temperature, the heat radiation from the high battery temperature to the ambient temperature is generated as heat. On the other hand, even in a fuel processor for reforming fuel into hydrogen, since a combustor is usually used for heating a reforming reaction of a reformer or the like, combustion exhaust gas or exhaust heat from the outside of the fuel processor is generated.

  If the heat generated from the fuel cell is used in this way, a hybrid operation with electric energy, that is, a cogeneration operation is performed. Therefore, a very economical and energy-efficient fuel cell system friendly to the global environment can be realized. In recent years, as one of the methods for preventing global warming, this fuel cell system that emits less carbon dioxide has attracted attention, and attention has been focused on its energy saving and economic efficiency.

  For this reason, development activities to introduce such fuel cell systems into homes have increased greatly, mainly in Japan, and there are systems that use exhaust heat generated from fuel cells installed in homes more widely than hot water and baths. It has been proposed (see, for example, Patent Documents 1 and 2). Furthermore, in Japan, with the assistance of the government budget, this household fuel cell system is being installed in ordinary households and large-scale demonstration tests are being carried out.

JP 2004-108608 A JP 2004-347288 A

  The problem that has been clarified in the demonstration test of the home fuel cell system as described above is that the energy saving and economical efficiency in the summer are reduced compared to the winter. This is because the demand for hot water supply is greatly reduced in the summer compared to the winter, and in the case of DSS operation, the start / stop of the fuel cell system increases, energy loss other than during power generation increases, and continuous operation increases. This is because the exhaust heat from the fuel cell cannot be used and the heat is dissipated into the atmosphere.

  As described above, the current household fuel cell system has a problem in that energy use and economy are deteriorated due to less use of hot water and baths in summer in general households. In order to increase this heat utilization, for example, it has been studied to apply it to a heat source of an absorption chiller or a desiccant air conditioner regenerator in the cooling operation of an air conditioner, but the utilization efficiency is low and it has been put to practical use. Not in. In addition, as in Patent Documents 1 and 2, proposals have been made for heat utilization that is not limited to hot water supply and baths. However, in these conventional technologies, waste heat utilization equipment cannot be handled by existing current products. In addition, the waste heat utilization system including the hot water storage tank is very complicated, and is not practical in terms of cost.

  In order to solve the above-described problems of the prior art, the present invention can easily and actively use waste heat even in summer when there is little demand for hot water supply, and can perform cogeneration operation with high overall energy efficiency. An object of the present invention is to provide a household fuel cell system excellent in energy saving and economical efficiency and an exhaust heat distribution unit used therefor.

  In order to achieve the above object, the present invention recovers exhaust heat from a fuel cell with hot water in a household fuel cell system equipped with a fuel cell that generates electricity by an electrochemical reaction using fuel and an oxidant. , Has a waste heat distribution unit that selectively distributes the recovered waste heat to the waste heat utilization equipment in the home by hot water distribution, the waste heat utilization equipment is a washing machine, air conditioner, dishwasher, toilet equipment And a plurality of waste heat utilization facilities including at least one facility selected from among the above and a water heater. This allows existing equipment to be used as waste heat utilization equipment simply by connecting it to a water supply system or hot water supply system of existing equipment, so exhaust heat from fuel cells is not limited to hot water supply and bath, It can be used effectively with existing facilities, and energy saving and economic efficiency can be improved.

  An exhaust heat distribution unit according to the present invention is used in the above system, recovers exhaust heat from the fuel cell with hot water, and distributes the recovered exhaust heat to hot water. A tank configured to be separated and independently configured to store hot water from the fuel cell; a plurality of distribution valves that selectively distribute the stored hot water to a plurality of waste heat utilization facilities; It has a control part which performs priority order control of warm water distribution to a plurality of above-mentioned exhaust heat utilization facilities by controlling the distribution valve of this.

  According to the present invention, it is possible to easily and positively use exhaust heat even in the summer when there is little demand for hot water supply, and to carry out cogeneration operation with high overall energy efficiency, which is excellent in energy saving and economical efficiency. A battery system and an exhaust heat distribution unit used therefor can be provided.

  Hereinafter, an embodiment of a household fuel cell system to which the present invention is applied will be described in detail with reference to the drawings.

[System configuration]
FIG. 1 is a block diagram showing a configuration of a household fuel cell system to which the present invention is applied. As shown in FIG. 1, the fuel cell system for home use of the present embodiment is separated from a fuel cell system main body package 100 for generating power and a fuel cell system main body package (hereinafter abbreviated as a main body package as appropriate) 100. The exhaust heat distribution unit 200 is provided as an independent unit.

  Here, the exhaust heat distribution unit 200 includes a hot water storage tank 201 that stores the exhaust heat from the fuel cell system main body package 100, and a plurality of distribution valves 211 to 215 that distribute the hot water stored in the hot water storage tank 201 to the exhaust heat utilization facility. Through these distribution valves 211 to 215, hot water is distributed to each of a plurality of waste heat utilization facilities such as a water heater 300, an air conditioner 400, a washing machine 500, a dishwasher 600, and a toilet facility 700. Are configured to be performed individually.

  The number of distribution valves shown in the figure is an example, and the exhaust heat distribution unit 200 may be provided with a number of distribution valves with a margin in advance, or by standardizing the distribution valves and piping, You may comprise so that a distribution valve can be expanded easily.

  The exhaust heat distribution unit 200 also includes a hot water circulation pump 202 that circulates hot water stored in the tank 201 between the fuel cell system main body package 100 and the hot water circulation pump 202. The waste heat distribution unit 200 further determines the priority order of the hot water distribution for the waste heat utilization equipment, acquires the condition designation regarding the priority order of the hot water distribution from the control unit 221 that controls the distribution valves 211 to 215, In addition, an operation / display unit 222 that visually displays information on the priority order of hot water distribution using a character string, a symbol mark, an icon, or the like is provided.

  The operation / display unit 222 may be incorporated in the main body of the exhaust heat distribution unit 200, but may be configured as an independent unit separated from the exhaust heat distribution unit 200, or both display / An operation unit may be provided. Furthermore, part or all of the control unit 221 can be incorporated into the independent display / operation unit 222.

[Configuration of main body package / Power generation principle]
FIG. 2 is a block diagram showing the configuration of the fuel cell system body package 100 in the household fuel cell system of the present embodiment. Hereinafter, in particular, the configuration and operation of the fuel cell system main body package 100 will be described by taking a solid polymer fuel cell system as an example.

  The fuel cell system body package 100 mainly includes a battery body (CSA: Cell Stack Assembly) 10 and a fuel processing system (FPS: Fuel Processing System) 20. The battery body 10 includes an anode electrode 11 and a cathode electrode 12. The fuel processing system 20 includes a fuel 21, a desulfurizer 22, a steam generator 23, a reformer 24, a CO shift reactor 25, a CO selective oxidizer 26, a steam separator 27, a reforming combustor 28, and reforming water. A pump 29, an exhaust heat exchanger & tank 30 are provided. The fuel is a hydrocarbon-based fuel, and specifically, for example, city gas or propane.

  The fuel processing system 20 also adjusts, shuts off, switches, or controls the flow of the fluid in order to control, shut off, switch, or control the cathode flow, a CO selective oxidation air blower 32, a combustion air blower 33, a fuel booster blower 34, a battery. A cooling water pump 35, a fuel cutoff valve 41, a starting fuel cutoff valve 42, a main fuel cutoff valve 43, a degassing cutoff valve 44, an off-gas check valve 45, a combustion air switching valve 46, and a water vapor flow rate adjustment valve 47 are provided. Yes.

  First, the power generation principle of the polymer electrolyte fuel cell system will be briefly described. For example, when city gas is used as the fuel, reforming from city gas to hydrogen gas is performed in the fuel processing system 20. The city gas fuel 21 passes through the desulfurizer 22, the sulfur content is removed by, for example, activated carbon or zeolite adsorption, and then passes through the reformer 24. Water is heated by the steam generator 23 in front of this, and the gasified steam joins the fuel gas. In the reformer 24, hydrogen is generated from the reaction of city gas and water vapor by the catalyst, but at the same time, CO is also generated. Since this steam reforming is an endothermic reaction, the reformer 24 includes a combustor for heating.

In the polymer electrolyte fuel cell, CO poisoning in a MEA (Membrane Electrode Assembly) composed of the electrolyte membrane and the catalyst layer of the battery main body 10 becomes a problem, and therefore it is necessary to oxidize CO to CO ₂ . Therefore, the CO shift reactor 25 advances the shift reaction with H ₂ O, and the CO selective oxidizer 26 performs the oxidation reaction by supplying air from the CO selective oxidation air blower 32 to such an extent that no CO poisoning is generated by the catalyst. Need to proceed.

  Although not shown for the sake of simplification, the catalytic reaction temperatures including the reformer 24 are different from each other, ranging from several hundred degrees of the reformer 24 to hundreds of degrees of the CO selective oxidizer 26. Since the temperature difference between the upstream and downstream of the gas is large, a water heat exchanger for reducing the downstream temperature is actually used.

  Next, main process reaction formulas for the respective catalysts are shown below. For example, in the case of city gas reforming mainly composed of a methane component, the steam reforming reaction is represented by equation (1), the CO shift reaction is represented by equation (2), and the CO selective oxidation reaction is represented by equation (3).

CH ₄ + 2H ₂ O → CO ₂ + 4H ₂ (1)
CO + H ₂ O → CO ₂ + H ₂ (2)
2CO + O ₂ → 2CO ₂ (3)

The reformed gas that has passed through the CO selective oxidizer 26 is mainly composed of components such as hydrogen, carbon dioxide, and excess water vapor. When the reformed gas composed of these components is sent to the anode electrode 11, the hydrogen gas in the reformed gas sent to the anode electrode 11 passes through the catalyst layer of MEA, and the proton H ⁺ passes through the electrolyte membrane. Water is generated in combination with oxygen and electrons in the air passing through the cathode 12 by the cathode air blower 31.

  Therefore, the anode electrode 11 becomes a negative electrode and the cathode electrode 12 becomes a positive electrode, and generates DC power with a potential. If an electric load is present between these potentials, it has a function as a power source. The off-gas flowing out from the outlet of the anode electrode 11 that is not used for power generation passes through the off-gas check valve 45 and is then supplied to the reforming combustor 28 of the steam generator 23 and the reformer 24 for combustion for heating. Used as gas.

  Further, the water vapor in the outlet of the cathode electrode 12 and the water vapor in the combustion exhaust gas are recovered by the exhaust heat exchanger 30a, thereby achieving water self-supporting in the system. On the other hand, the exhaust heat of the battery main body 10 is recovered by the exhaust heat exchanger 30b disposed in the circulation line of the battery cooling water pump 35. The hot water heated by exchanging heat in the exhaust heat exchangers 30 a and 30 b is recovered from the fuel cell system main body package 100 by the operation of the hot water circulation pump 202 and stored in the hot water storage tank 201 in the exhaust heat distribution unit 200. The

  In this case, the hot water stored in the hot water storage tank 201 is distributed to any one of a plurality of waste heat utilization facilities such as the water heater 300, the air conditioner 400, the washing machine 500, the dishwasher 600, and the toilet facility 700. . In the state where the hot water stored in the hot water storage tank 201 is not distributed and the high temperature hot water is stored up to a level higher than the hot water outlet in the hot water storage tank 201, the circulating water temperature returning to the main body package 100 rises. The power generation of the package 100 is stopped.

  Moreover, the operation method at the time of starting after a power generation stop is as follows. That is, first, when an operation start command is given, the combustion air blower 33 is started with the combustion air switching valve 46 opened, and the combustion chamber in the reformer 24 is purged with air. In this case, the combustion air is supplied from the combustion air blower 33 not only as premixed air for the starting fuel but also as diffusion air into the combustion chamber.

  When the air purge of the combustion chamber in the reformer 24 is completed, a spark from, for example, a spark plug for starting fuel ignition is generated in the combustion chamber. When the fuel cutoff valve 41 and the startup fuel cutoff valve 42 are opened with the main fuel cutoff valve 43 closed and the deaeration cutoff valve 44 open, the fuel cutoff valve 41 and the startup fuel cutoff valve 42 pass through. The startup fuel thus boosted is boosted by the fuel booster blower 34 and introduced into the combustion chamber in the reformer 24 to be ignited to form a flame.

  Note that the burner used in the combustion chamber in the reformer 24 is an integrated burner that serves both for start-up and for power generation, and the methane-based start fuel burns from hydrogen-based fuel that is off-gas fuel during power generation. Since the speed is low and it is easy to blow out, premixed combustion is performed to improve combustibility.

  Combustion continues in the combustion chamber in the reformer 24, and the combustion gas is heated to heat the reformer 24, an electric heater (not shown), a CO shift reactor 25, a CO selective oxidizer 26, steam When the separator 27 and the like reach a predetermined temperature, the reformed water supplied to the steam separator 27 by the reforming water pump 29 becomes steam there. When the water vapor is separated in the water vapor separator 27 as described above, the water vapor flow rate control valve 47 is opened by the water vapor and supplied to the fuel reforming line. Then, the main fuel cutoff valve 43 is opened and the fuel 21 is modified. The reforming reaction is started by being supplied into the mass device 24. At the same time as the fuel 21 is supplied into the reformer 24, the starting fuel cutoff valve 42, the desorber cutoff valve 44, and the combustion air switching valve 46 are closed.

  After the reforming reaction in the reformer 24 is started, the reformed gas oxidized by the air of the CO selective oxidizer air blower 32 and discharged from the outlet of the CO selective oxidizer 26 is mainly hydrogen, as described above. When the reformed gas composed of these components is supplied to the anode electrode 11 of the battery body 2, the inverter is activated (not shown) and power generation is started. .

  When the reformed gas composed of such components is supplied to the anode electrode 11, the hydrogen gas in the reformed gas is combined with oxygen and electrons in the air supplied to the cathode electrode 12 to generate water. When the anode electrode 11 becomes a negative (−) electrode and the cathode electrode 12 becomes a positive (+) electrode, and a DC power is generated with a potential, and an electric load exists between the potentials, As described above, the functions can be provided.

  On the other hand, the off-gas that exits from the outlet of the anode 11 that does not contribute to power generation passes through the off-gas check valve 45 and is then supplied to the steam generator 23 and the reforming combustor 28. The off-gas fuel supplied to the reforming combustor 28 ignites and starts stable diffusion combustion with the main fuel air. Thereafter, the cathode air is supplied to the battery body 10 and when the inverter is activated, the power generation of the body package 100 is started.

[Action]
Below, the hot water distribution with respect to an exhaust heat utilization equipment is demonstrated as an effect | action by the domestic fuel cell system of this embodiment.

  First, in the household fuel cell system of the present embodiment, as described above, when the main body package 100 generates power, the exhaust heat is absorbed by the heat exchange of the exhaust heat exchangers 30a and 30b as described above. The warm water obtained as a result of the warming is recovered from the main body package 100 by the operation of the hot water circulation pump 202 and stored in the hot water storage tank 201 in the exhaust heat distribution unit 200. That is, the exhaust heat generated by the power generation of the main body package 100 is recovered as hot water by the exhaust heat distribution unit 200.

  The hot water stored in the hot water storage tank 201 is controlled by the control unit 221 of the exhaust heat distribution unit 200 to control the distribution valves 211 to 215, so that the water heater 300, the air conditioner 400, the washing machine 500, and the dishwasher are used. Hot water is distributed to any of a plurality of waste heat utilization facilities 600 and toilet facilities 700. In this case, the control unit 221 determines the priority order of hot water distribution for the waste heat utilization equipment based on the condition designation acquired from the user by the operation / display unit 222, and sets the distribution valves 211 to 215 according to the determined priority order. Control.

  For example, the amount of hot water stored in the hot water storage tank 201 when the priority order is “air conditioner”, “washing machine”, “dishwasher”, “toilet equipment”, “hot water heater” in summer, for example. When the amount of water is small, only the distribution valve 212 to the air conditioner 400 is opened and the other distribution valves 211 and 213 to 215 are closed, and additionally, the distribution valve to the washing machine 500 is added according to the amount of stored hot water. Operation such as opening 213 and further opening the distribution valve 214 to the dishwasher 600 can be considered. In addition, the control of the distribution valves 211 to 215 is not limited to such an open / close control, but of course an operation for controlling the distribution amount is possible. Note that the control of the distribution amount by such valve control is an existing technique in the field of fluid control, and thus further description thereof is omitted.

  In addition, regarding acquisition of the condition designation from the user for determining the priority order, for example, by the operation / display unit 222, “water heater”, “air conditioner”, “washing machine”, “tableware washing” registered in advance `` Machine '', `` toilet equipment '', etc. individually display character strings, symbol marks, icons, etc. that indicate waste heat utilization facilities, and the user selects these individual displays in sequence, etc. The priority order is determined and the determination result is displayed. For example, when a character string is used, priority order display such as “hot water supply> air conditioning> laundry> tableware> toilet” can be considered.

  Furthermore, a plurality of modes such as a manual designation mode and an automatic learning designation mode may be prepared as the priority order designation mode, and the mode may be designated by the user. For example, in the manual designation mode, the user designates the priority order as described above by manual operation, determines the priority order obtained as a result of the operation, and obtains from the user in the automatic learning designation mode. An operation such as automatically determining the priority order using the past designated history can be considered.

  Furthermore, as one of the automatic learning designation modes, an energy saving mode considering energy saving and economic efficiency may be prepared. Specifically, in the energy saving mode, by setting in advance some index values indicating the evaluation of energy saving and economic efficiency for each facility, and by setting a learning algorithm using these index values in advance. For example, an operation such as determining the priority of hot water distribution according to the learning result using both the index value of energy saving and economic efficiency and the designation from the user can be considered.

  In addition, as some index values indicating the evaluation of energy saving and economic efficiency, the amount and temperature of hot water supplied from the exhaust heat distribution unit 200, another energy usage reduced by the supply, the cost of reducing water usage, Etc. are considered. Such an index value may be registered manually by the person in charge of the system installer as part of the work when installing the home fuel cell system and connecting it to existing household equipment, but is assumed in advance. Depending on the type of waste heat utilization equipment, basic index values may be prepared in advance and automatically registered by selecting the type of equipment to be connected. Alternatively, a plurality of index values prepared in advance may be displayed so that they can be appropriately selected from them.

  In addition, although the user may register the waste heat utilization facility by the operation / display unit 222 using a simple menu selection, the home fuel cell system is installed and connected to the existing home facility. If the person in charge of the system installer performs as part of the work when doing this, the burden on the user can be reduced.

[Individual waste heat utilization system]
3 to 7 are block diagrams showing individual exhaust heat utilization systems configured by connecting individual exhaust heat utilization facilities to the distribution valves 211 to 215 of the exhaust heat distribution unit 200, respectively. Hereinafter, the individual exhaust heat utilization systems will be sequentially described with reference to these drawings. In each figure, A indicates hot water supplied to the exhaust heat utilization facility, and B indicates warm water that returns to the exhaust heat distribution unit 200 after being exhausted by the exhaust heat utilization facility.

[Heat-heater waste heat utilization system]
FIG. 3 is a block diagram showing an exhaust heat utilization system of the water heater 300 configured by connecting the piping of the distribution valve 211 of the exhaust heat distribution unit 200 to the existing water heater 300.

  As shown in FIG. 3, since a hot water and tap water mixer called a blender 301 is usually provided on the upstream side of the water heater 300, the waste heat utilization system of the water heater 300 is a distribution valve 211. By connecting this pipe to the blender 301, it can be easily configured. Such waste heat utilization in the waste heat utilization system of the water heater 300 is realized as follows.

  First, when the hot water supplied from the exhaust heat distribution unit 200 through the distribution valve 211 is higher than the set temperature, the hot water is diluted with tap water and passed through the water heater 300 and used as hot water or bath water. The heating by the burner 302 is not performed. On the other hand, when the hot water supplied from the exhaust heat distribution unit 200 is lower than the set temperature, the hot water is diluted with tap water by the blender 301 according to the difference from the set temperature, and then set by the burner 302. Heated to temperature, used as hot water or bath water.

  As described above, the exhaust heat utilization system of the water heater is configured and the hot water is distributed from the exhaust heat distribution unit, so that the exhaust heat utilization of the fuel cell can be easily and actively performed.

[Air-conditioner exhaust heat utilization system]
FIG. 4 is a block diagram showing an exhaust heat utilization system of the air conditioner 400 configured by connecting the piping of the distribution valve 212 of the exhaust heat distribution unit 200 to the existing air conditioner 400.

  As shown in FIG. 4, the indoor unit 401 of the air conditioner 400 includes a heat exchanger 402 and a cross flow fan 403. Furthermore, the heat exchanger 402 includes an evaporating heat exchanger 402a in which the refrigerant flows upstream in the airflow direction of the cross flow fan 403, and a heating heat exchanger 402b in which hot water flows downstream. Therefore, the exhaust heat utilization system of the air conditioner 400 can be easily configured by connecting the piping of the distribution valve 212 to the heating heat exchanger 402b. Such exhaust heat utilization in the exhaust heat utilization system of the air conditioner 400 is realized as follows.

  First, during a dehumidifying operation in summer or the like, warm water is supplied from the exhaust heat distribution unit 200 to the heating heat exchanger 402b through the distribution valve 212. Thereby, since the air dehumidified and cooled by the evaporative heat exchanger 402a is heated by the heating heat exchanger 402b, the air exhausted into the room is appropriately warmed, and the conventional room is cooled and becomes uncomfortable. Can be avoided. The hot water cooled by the cool air in the heating heat exchanger 402b returns to the exhaust heat distribution unit 200 from the lower piping of the hot water storage tank 201. When the user desires a decrease in room temperature and selects a cooling operation during dehumidification, the air conditioner 400 may be operated without supplying hot water to the heating heat exchanger 402b.

  In this way, by configuring the exhaust heat utilization system of the air conditioner and distributing hot water from the exhaust heat distribution unit during the dehumidifying operation, the exhaust heat utilization of the fuel cell is easily and actively performed even in summer when there is little demand for hot water supply. be able to.

[Washing heat exhaust system]
FIG. 5 is a block diagram showing a waste heat utilization system of the washing machine 500 configured by connecting the piping of the distribution valve 213 of the waste heat distribution unit 200 to the existing washing machine 500.

  As shown in FIG. 5, when the washing machine 500 is a washing machine with a drying function, it has a drying heat exchanger 501 for drying clothes. For such a washing machine 500, the hot water from the exhaust heat distribution unit 200 may be used as a heat source for drying, or may be used as washing water supplied to the washing tub 502. In the former case, the hot water cooled by the fan (not shown) in the drying heat exchanger 501 returns to the exhaust heat distribution unit 200 from the lower pipe of the hot water storage tank 201. When used for the latter washing water, the hot water does not return to the waste heat distribution unit 200.

  Moreover, the 1st orifice 503 which adjusts the amount of water supply is provided in the water supply opening of the washing machine 500, and when the hot water is too hot or the amount of water is insufficient, the amount of water supply is adjusted by the first orifice 503. can do. 5 shows a configuration in which the drying heat exchanger 501 and the washing tub 502 are separated in parallel with respect to the flow of hot water, and the flow is switched by the two two-way valves 511 and 512, but this is only an example. Instead, a three-way valve may be used instead, or it may be configured in series with the drying heat exchanger 501 upstream of the hot water and the washing tub 502 downstream.

  When using hot water from the waste heat distribution unit 200 as washing water, the fan of the drying heat exchanger 501 is stopped to supply hot water to the washing tub 502, and when using as a drying heat source, the fan is operated, The cooled hot water is returned to the exhaust heat distribution unit 200. The two-way valves 511 and 512 may be either manually operated or electrically operated. However, when an electromagnetic valve is used, it is necessary to perform wiring so as to be interlocked with the electromagnetic valve control of the exhaust heat distribution unit 200.

  In this way, by configuring the waste heat utilization system of the washing machine and distributing hot water from the waste heat distribution unit as its drying heat source or washing water, the waste heat utilization of the fuel cell can be easily and easily performed even in the summer when there is little demand for hot water supply. It can be done actively. In particular, when warm water is used as the washing water, an effect that the cleaning ability can be improved as compared with the case where only tap water is used is also obtained.

[Waste heat utilization system for dishwashers]
FIG. 6 is a block diagram showing an exhaust heat utilization system of the dishwasher 600 configured by connecting the piping of the distribution valve 214 of the exhaust heat distribution unit 200 to the existing dishwasher 600.

  As shown in FIG. 6, the dishwasher 600 generally includes a drying heat exchanger 601 for drying the dishes. For such a dishwasher 600, the hot water from the exhaust heat distribution unit 200 may be used as the heat source for drying, or may be used as the cleaning water supplied to the cleaning tank 602. In the former case, the hot water cooled by the fan (not shown) in the drying heat exchanger 601 returns to the exhaust heat distribution unit 200 from the lower pipe of the hot water storage tank 201. When used for the latter cleaning water, the hot water does not return to the exhaust heat distribution unit 200.

  Moreover, the 2nd orifice 603 which adjusts the amount of water supplies is provided in the water supply opening of the dishwasher 600, and when the hot water is too hot or the amount of water is insufficient, the amount of water supply is reduced by the second orifice 603. Can be adjusted. 6 shows a configuration in which the drying heat exchanger 601 and the washing tank 602 are separated in parallel with respect to the flow of hot water, and the flow is switched between the two two-way valves 611 and 612. However, this is only an example. Instead, a three-way valve may be used instead, or it may be configured in series with the drying heat exchanger 601 upstream of the hot water and the washing tank 602 downstream.

  When using hot water from the waste heat distribution unit 200 as washing water, the fan of the drying heat exchanger 601 is stopped to supply hot water to the washing tub 602, and when using as a drying heat source, the fan is operated and cooled. The warm water is returned to the exhaust heat distribution unit 200. The two-way valves 611 and 612 may be either manually operated or electrically operated. However, when an electromagnetic valve is used, it is necessary to perform wiring so as to be interlocked with the electromagnetic valve control of the exhaust heat distribution unit 200.

  In this way, by configuring the waste heat utilization system of the dishwasher and distributing hot water from the waste heat distribution unit as its drying heat source or washing water, it is easy to use the waste heat of the fuel cell even in the summer when there is little demand for hot water supply. And it can be done actively. In particular, when warm water is used as the cleaning water, the cleaning ability can be improved as compared with the case where only tap water is used.

[Toilet facility waste heat utilization system]
FIG. 7 is a block diagram showing an exhaust heat utilization system of the toilet facility 700 configured by connecting the piping of the distribution valve 215 of the exhaust heat distribution unit 200 to the existing toilet facility 700.

  As shown in FIG. 7, here, as an example, the case where the existing toilet facility 700 is a flush shower toilet is shown, but a toilet facility without a shower function is also applicable as a waste heat utilization facility. It is.

  In the case of a flush shower toilet, the toilet facility 700 includes a toilet cleaning tank 701, a toilet 702, a shower unit 703, and the like. For such toilet facilities 700, the hot water from the waste heat distribution unit 200 is mixed with tap water whose amount of water has been adjusted at the third orifice 704 in order to cool down to the use temperature at the time of hand washing, and then for toilet washing. It is supplied to the tank 701.

  After using the toilet, the warm water supplied to the washing tank 701 can be used as the toilet 702 and washing water for hand washing. Therefore, the washing ability is higher than that of cold water, and the toilet 72 and hands can be kept clean. it can. On the other hand, since warm water can be used as it is when using a shower, the amount of heater heater power normally provided in a flush shower toilet can be minimized, which is very economical. In addition, when the hot water is lower than the set temperature, the heater may be used as an auxiliary.

  In this way, by constructing a waste heat utilization system for toilet facilities and distributing hot water from the waste heat distribution unit as washing water or shower water, the waste heat utilization of the fuel cell can be easily and easily performed even in the summer when there is little demand for hot water supply. It can be done actively. In particular, when warm water is used as the cleaning water, the effect of improving the cleaning ability of the toilet and hand-washing can be obtained as compared with the case where only tap water is used.

[effect]
According to the present embodiment as described above, each distribution valve of the exhaust heat distribution unit is connected to a water supply system or a hot water supply system of an existing facility such as a water heater, an air conditioner, a washing machine, a dishwasher, or a toilet facility, respectively. By simply doing, existing facilities can be used as waste heat utilization facilities. As a result, many existing facilities can be used as they are compared to the conventional technology that could not be handled by existing facilities, and the cogeneration operation that uses both electricity and heat is effective by minimizing the frequency of shutdown. In addition, since the entire system can be simplified, it is highly practical in terms of cost.

  Therefore, even in the summer when there is little demand for hot water supply, it is possible to easily and actively use exhaust heat, not limited to hot water supply and baths. It is possible to provide an excellent fuel cell system for home use. In addition, since the amount of exhaust heat released into the atmosphere can be reduced, operation that is friendly to the global environment can be realized.

  In addition, since the exhaust heat distribution unit in the present invention is configured separately from the fuel cell system main body, the present invention provides a single exhaust heat distribution unit having a hot water storage tank, a plurality of distribution valves, and a control unit. This embodiment can also be implemented. Since the exhaust heat distribution unit in the present invention can be combined with various existing fuel cell system bodies configured to recover the exhaust heat with hot water, it is more economical than the case where the entire system is newly constructed. Is.

  Further, as described above, the waste heat distribution unit according to the present invention includes an index value indicating an evaluation of energy saving and economic efficiency of a facility unit related to hot water distribution for a plurality of waste heat utilization facilities, and a condition relating to a priority order acquired from a user. By using a designated history and learning based on a preset algorithm, it is possible to perform priority control of hot water distribution according to the learning result. Therefore, not only the user's request but also the energy saving and the economical efficiency, it is possible to always distribute the hot water with the optimum priority order and to use the optimum exhaust heat. Various existing techniques can be applied as a control technique using such learning.

[Other Embodiments]
It should be noted that the present invention is not limited to the above-described embodiments, and various other variations can be implemented within the scope of the present invention. First, the system configuration and the configuration of the exhaust heat utilization system shown in the drawings are merely examples, and the specific system configuration and the configuration of the exhaust heat utilization system can be appropriately selected. In particular, since the present invention relates to the use of exhaust heat of a household fuel cell system, the specific configuration of the fuel cell system body is not limited as long as the exhaust heat of the fuel cell can be recovered with hot water. Absent.

  In addition, the facility illustrated as the waste heat utilization facility is an example, and other excellent domestic effects that can be used with hot water can be similarly used as the waste heat utilization facility. Is.

The block diagram which shows the structure of the domestic fuel cell system to which this invention is applied. The block diagram which shows the structure of the fuel cell system main body package shown in FIG. The block diagram which shows the waste heat utilization system | strain of the water heater comprised by connecting the distribution valve of the waste heat distribution unit shown in FIG. 1 to the existing water heater. The block diagram which shows the waste heat utilization system | strain of the air conditioning machine comprised by connecting the distribution valve of the waste heat distribution unit shown in FIG. 1 to the existing air conditioning machine. The block diagram which shows the waste heat utilization system | strain of the washing machine comprised by connecting the distribution valve of the waste heat distribution unit shown in FIG. 1 to the existing washing machine. The block diagram which shows the waste-heat utilization system | strain of the dishwasher comprised by connecting the distribution valve of the waste heat distribution unit shown in FIG. 1 to the existing dishwasher. The block diagram which shows the waste heat utilization system | strain of the toilet equipment comprised by connecting the distribution valve of the waste heat distribution unit shown in FIG. 1 to the existing toilet equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Battery main body 11 ... Anode electrode 12 ... Cathode electrode 20 ... Fuel processing system 21 ... Fuel 22 ... Desulfurizer 23 ... Steam generator 24 ... Reformer 25 ... CO shift reactor 26 ... CO selective oxidizer 27 ... Steam separation Regenerator 28 ... Reforming combustor 29 ... Reforming water pumps 30a, 30b ... Exhaust heat exchanger 31 ... Cathode pole air blower 32 ... CO selective oxidation air blower 33 ... Combustion air blower 34 ... Fuel booster blower 35 ... battery coolant pump 41 ... fuel shutoff valve 42 ... start fuel shutoff valve 43 ... main fuel shutoff valve 44 ... degassing shutoff valve 45 ... offgas check valve 46 ... combustion air switching valve 47 ... steam flow rate control valve 100 ... Fuel cell system main body package 200 ... Waste heat distribution unit 201 ... Hot water storage tank 202 ... Hot water circulation pump 211-215 ... Distribution valve 221 ... Control unit 222 ... Operation / display unit 300 Water heater 301 ... Blender 302 ... Burner 400 ... Air conditioner 401 ... Indoor unit 402a ... Evaporation heat exchanger 402b ... Heating heat exchanger 403 ... Cross-flow fan 500 ... Washing machine 501 ... Drying heat exchanger 502 ... Washing tub 503 ... First Orifice 600 ... Dishwasher 601 ... Dry heat exchange 602 ... Washing tank 603 ... Second orifice 700 ... Toilet equipment 701 ... Toilet washing tank 702 ... Toilet 703 ... Shower unit 704 ... Third orifice

Claims (10)

In a household fuel cell system equipped with a fuel cell that generates electricity by an electrochemical reaction using a fuel and an oxidant,
An exhaust heat distribution unit that recovers exhaust heat from the fuel cell with hot water, and selectively distributes the recovered exhaust heat to domestic exhaust heat utilization equipment by distributing hot water;
The waste heat utilization facility is a plurality of waste heat utilization facilities including at least one facility selected from a washing machine, an air conditioner, a dishwasher, and a toilet facility, and a water heater. Household fuel cell system. The domestic fuel cell system according to claim 1, wherein the waste heat distribution unit is configured separately from the fuel cell. The waste heat distribution unit has a tank for storing hot water from the fuel cell, and a plurality of distribution valves for selectively distributing the hot water stored in the waste heat utilization equipment in units of equipment. The domestic fuel cell system according to claim 1 or 2, wherein the fuel cell system is for domestic use. The domestic fuel according to any one of claims 1 to 3, wherein the exhaust heat distribution unit includes a control unit that performs priority control of warm water distribution to the plurality of waste heat utilization facilities. Battery system. The waste heat distribution unit has an operation unit that acquires a condition designation related to a priority order of hot water distribution for the plurality of waste heat utilization facilities according to a user operation,
The control unit is set in advance using an index value indicating an evaluation of energy saving and economic efficiency of a facility unit relating to hot water distribution to the plurality of waste heat utilization facilities, and a condition designation history regarding priority obtained from a user. The home fuel cell system according to claim 4, wherein the priority control of the hot water distribution according to the learning result is performed by learning based on the algorithm. 2. An exhaust heat utilization system that utilizes exhaust heat supplied to the air conditioner for operation in which air that has fallen in temperature due to dehumidification during dehumidification is used to prevent a decrease in room temperature. Item 6. The household fuel cell system according to any one of Items 5. 7. The exhaust heat utilization system for utilizing the exhaust heat supplied to the washing machine as at least one of washing water and a heat source for washing and drying. 8. Home fuel cell system. 8. The exhaust heat utilization system for utilizing the exhaust heat supplied to the dishwasher as at least one of washing water and a heat source for drying the dish, according to claim 1. The household fuel cell system as described. 9. The exhaust heat utilization system for utilizing the exhaust heat supplied to the toilet facility as at least one of toilet flush water or a heat source for shower heating. 10. Home fuel cell system. Used in a domestic fuel cell system equipped with a fuel cell that generates electricity by an electrochemical reaction using fuel and an oxidant, recovering the exhaust heat from the fuel cell with hot water, and distributing the recovered exhaust heat to hot water In the exhaust heat distribution unit,
Separately configured from the fuel cell,
A tank for storing hot water from the fuel cell;
A plurality of distribution valves for selectively distributing the hot water stored in a facility unit to a plurality of waste heat utilization facilities;
An exhaust heat distribution unit comprising: a control unit that performs priority control of hot water distribution for the plurality of waste heat utilization facilities by controlling the plurality of distribution valves.

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