JP2007001799A - Hydrogen fuel-supplying system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen fuel-supplying system having a plurality of reactors and capable of favorably following the requirement of increase in a hydrogen supply amount. <P>SOLUTION: A plurality of reactors 18A and 18B composing the hydrogen fuel-supplying system repeatedly carry out a reforming process and a regeneration process alternately in different timing. The reforming process comprises generating a hydrogen-containing fuel gas by reforming a raw material, and the regeneration process comprises performing temperature elevation and heat accumulation by combustion of a gas for regeneration after heat consumption in the reforming process. When a quick acceleration is required in a timing in which in one reactor 18B, the time of from start to a switch timing T1 to be switched from the reforming process to the regeneration process is below a prescribed time, a control device controls the reactor 18B to continue the operation of reforming without switching from reforming to regeneration. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydrogen fuel supply system for supplying a fuel gas containing hydrogen to a fuel cell, for example.

For example, as a hydrogen fuel supply system that supplies fuel gas containing hydrogen to a fuel cell, the reforming process is performed by reacting hydrocarbon fuel and water vapor to produce a hydrogen-containing gas, and catalytic combustion of the regeneration gas. There is known a system for performing batch hydrocarbon reforming in which a regeneration step for raising the catalyst temperature lowered in the quality step is repeated alternately (see, for example, Patent Document 1). The system described in this document includes a pair of reactors that can perform a reforming step and a regeneration step, and the other reactor performs the regeneration step while one of the reactors performs the reforming step. Thus, the hydrogen-containing gas is continuously supplied to the fuel cell while performing the hydrocarbon reforming in a batch manner.
US Patent Application Publication No. 2004 / 0175326A1

  By the way, in the conventional technology as described above, the gas discharged from the reactor immediately after switching from the regeneration process to the reforming process is the same as the hydrogen-containing gas discharged in a state where the reforming process is stably performed. In comparison, the hydrogen amount or the hydrogen concentration is lowered. For this reason, if the timing for requesting an increase in hydrogen supply (discharge) and the timing for switching from the reactor regeneration process to the reforming process are almost the same, the actual hydrogen supply will decrease in response to the request for an increase in hydrogen supply. Cause problems.

  An object of the present invention is to obtain a hydrogen fuel supply system that includes a plurality of reactors and can follow the demand for an increase in the amount of hydrogen supply satisfactorily in consideration of the above facts.

  In order to achieve the above object, a hydrogen fuel supply system according to claim 1 provides a reforming step for generating a fuel gas containing hydrogen from a supplied raw material, and supplies a temperature lowered by the reforming step. A plurality of reactors that can be switched so as to perform a regeneration step of burning the generated regeneration gas to a temperature capable of reforming, and discharging the fuel gas while supplying the raw material to each reactor A switching device for switching between a first state and a second state in which the regeneration gas is discharged while supplying the regeneration gas to the reactor; and from the first state of at least two of the reactors to the second state The timing for switching to two states is different and the first state and the second state are alternately generated in the plurality of reactors, respectively, and from the first state of one of the reactors First When a request for an increase in the fuel gas supply amount by a predetermined amount or a predetermined increase rate is made at a time when the time until the switching timing to the state is equal to or less than a predetermined time, the one reactor is at the switching timing. And a control device that switches the switching device so that the supply amount of the raw material is increased while maintaining the first state without switching to the second state.

  In the hydrogen fuel supply system according to claim 1, each of the plurality of reactors includes a reforming step that occurs in the switching (selection) state to the first state and a regeneration step that occurs in the switching state to the second state. Alternately. Since the switching timing from the reforming process to the regeneration process is shifted in at least two reactors, hydrogen-containing fuel gas can be continuously supplied by a plurality of batch reactors. If there is a request for an increase in the hydrogen supply (discharge) amount over a predetermined amount or a predetermined increase rate between a predetermined time before the switching timing from the reforming process to the regeneration process of one reactor and the switching timing, The apparatus maintains the reforming process of the one reactor that is performing the reforming process even when the switching timing is reached. As a result, during the increase period of the supply amount of the hydrogen-containing fuel gas, the fuel gas is stably discharged from the reactor maintained in the reforming process, and the hydrogen amount (concentration) in the fuel gas is temporarily reduced. It is prevented that it falls.

  As described above, the hydrogen fuel supply system according to claim 1 includes a plurality of reactors, and can satisfactorily follow the demand for increasing the hydrogen supply amount.

  In order to achieve the above object, a hydrogen fuel supply system according to the invention described in claim 2 generates a fuel gas containing hydrogen from the supplied raw material, and supplies a temperature lowered by the reforming step. A plurality of reactors that can be switched so as to perform a regeneration step of burning the generated regeneration gas to a temperature capable of reforming, and discharging the fuel gas while supplying the raw material to each reactor A switching device for switching between a first state and a second state in which the regeneration gas is discharged while supplying the regeneration gas to the reactor; and from the first state of at least two of the reactors to the second state A predetermined amount or a predetermined increase in the fuel gas supply amount so as to cause the first state and the second state to alternately occur in each of the plurality of reactors while changing the timing for switching to the two states. The supply amount of the raw material to the one reactor is increased without causing the one reactor to switch from the first state to the second state during the period when the increase request is made. And a control device for switching the switching device.

  In the hydrogen fuel supply system according to claim 2, each of the plurality of reactors includes a reforming step that occurs in the switching (selection) state to the first state and a regeneration step that occurs in the switching state to the second state. Alternately. Since the switching timing from the reforming process to the regeneration process is shifted in at least two reactors, hydrogen-containing fuel gas can be continuously supplied by a plurality of batch reactors. For example, when the timing for switching from the reforming process to the regeneration process of one reactor arrives (determined) during a period when an increase in the hydrogen supply (discharge) amount that is a predetermined amount or a predetermined increase rate is requested. The control device maintains one reactor that is performing the reforming process at the switching timing in the reforming process without switching to the regeneration process. As a result, during the increase period of the supply amount of the hydrogen-containing fuel gas, the fuel gas is stably discharged from the reactor maintained in the reforming process, and the hydrogen amount (concentration) in the fuel gas is temporarily reduced. It is prevented that it falls.

  Thus, the hydrogen fuel supply system according to claim 2 is provided with a plurality of reactors and can satisfactorily follow the demand for increasing the hydrogen supply amount.

  A hydrogen fuel supply system according to a third aspect of the present invention is the hydrogen fuel supply system according to the first or second aspect, wherein the reformer outputs a signal corresponding to the temperature or heat quantity of each reactor to the control device. The reaction apparatus further includes a capacity detecting means and a heating means capable of heating each of the reactors, and the control device is maintained in the first state based on an output signal of the reforming capacity detecting means. When it is determined that the heat retention amount of the reactor is lower than the set heat amount, the heating means of the reactor is activated.

  In the hydrogen fuel supply system according to claim 3, for example, the reactor maintained in the reforming process without being switched to the regeneration process at the switching timing from the reforming process to the regeneration process as described above maintains the reforming process. When the time becomes long, the heat storage amount may be insufficient with respect to the required reforming amount. When the controller determines that the heat storage amount of the reactor is lower than the set heat amount based on the detection result of the reforming capacity detection means, that is, the temperature or the heat storage amount of the reactor, Heat the vessel. As a result, if the set heat amount is set as the heat amount that can maintain the reforming step for generating the required reforming amount (fuel gas generation amount), an increase in the hydrogen supply (discharge) amount exceeding the predetermined increase rate is requested. During this period, the one reactor can be maintained in the reforming process. In addition, as a heating means, what uses external heat sources, such as a heater, may be employ | adopted, for example, the means to promote internal heat_generation | fever, such as a means to improve the partial oxidation ratio in a reactor, may be employ | adopted.

  A hydrogen fuel supply system according to a fourth aspect of the present invention is the hydrogen fuel supply system according to any one of the first to third aspects, wherein the control device is configured to perform the first state of one of the reactors. When a request for reduction of the fuel gas supply amount to a predetermined amount or a predetermined reduction rate is made at a time when the time from the switch to the second state is a predetermined time or less separately, before the switch timing The switching device is switched so that another reactor switches from the second state to the first state.

  5. The hydrogen fuel supply system according to claim 4, wherein a hydrogen supply of a predetermined amount or a predetermined reduction rate or more is performed between a predetermined time before the switching timing from the reforming process to the regeneration process of one reactor and the switching timing. When there is a request to reduce the amount, the control device switches another reactor from the regeneration process to the reforming process before reaching the switching timing. As a result, when there is a request to increase the hydrogen supply immediately after the request to reduce the hydrogen supply, the elapsed time from switching to the reforming process is short, and the other reactor having a large heat storage amount is used. Hydrogen-containing fuel gas can be supplied. That is, it is possible to reduce the execution frequency of the control for maintaining the reforming process after the switching timing described above, the operation time of the heating means, and the like. If there is a request for an increase in the amount of hydrogen supply exceeding a predetermined rate at the end of the reforming step of another reactor, the control according to any one of claims 1 to 3 is performed.

  A hydrogen fuel supply system according to a fifth aspect of the invention includes a reforming step of generating a fuel gas containing hydrogen from a supplied raw material, and combustion of a regeneration gas supplied with a temperature lowered by the reforming step A plurality of reactors that can be switched to perform a regeneration step that raises the temperature to a reformable temperature, a first state in which the fuel gas is discharged while supplying the raw materials to the reactors, A switching device for switching between the second state in which the regeneration gas is discharged while supplying the regeneration gas to the reactor, and the switching timing of the at least two of the reactors from the first state to the second state. The first state and the second state are alternately generated in the respective reactors in a different manner, and the timing of switching the first reactor from the first state to the second state is different. Time is predetermined When the fuel gas supply amount is requested to be reduced by a predetermined amount or a predetermined reduction rate or more at a time that is less than or equal to the interval, the other reactor is moved from the second state to the first state before the switching timing. And a control device for switching the switching device so as to switch to a state.

  In the hydrogen fuel supply system according to claim 5, each of the plurality of reactors includes a reforming step that occurs in the switching (selection) state to the first state and a regeneration step that occurs in the switching state to the second state. Alternately. Since the switching timing from the reforming process to the regeneration process is shifted in at least two reactors, hydrogen-containing fuel gas can be continuously supplied by a plurality of batch reactors. If there is a request for reduction of the hydrogen supply amount over a predetermined amount or a predetermined reduction rate between a predetermined time before the switching timing from the reforming step to the regeneration step of one reactor and the switching timing, the control device Before the switching timing is reached, another reactor is switched from the regeneration process to the reforming process. As a result, when there is a request to increase the hydrogen supply immediately after the request to reduce the hydrogen supply, the elapsed time from switching to the reforming process is short, and the other reactor having a large heat storage amount is used. Hydrogen-containing fuel gas can be supplied.

  As described above, the hydrogen fuel supply system according to the present invention includes a plurality of reactors, and has an excellent effect of being able to satisfactorily follow the demand for increasing the hydrogen supply amount.

  A fuel cell system 10 to which a hydrogen fuel supply system 12 according to an embodiment of the present invention is applied will be described with reference to FIGS. 1 to 9. The fuel cell system 10 according to this embodiment constitutes a power supply system for supplying electric power to a motor for driving an automobile having a relatively large load fluctuation. This power supply system may be configured as a hybrid system including a battery in addition to the fuel cell system 10, or may be configured by the fuel cell system 10 alone. First, the overall configuration of the fuel cell system 10 of the present invention will be described, and then the fuel cell (hydrogen) supplied to the fuel cell 14 during rapid acceleration of the automobile to which the fuel cell system 10 is applied, which is the main part of the present invention. Will be described.

(Fuel cell system configuration)
FIG. 5 shows a system configuration diagram (system flow sheet) of the fuel cell system 10. As shown in this figure, a fuel cell system 10 includes a hydrogen fuel supply system 12, a fuel cell 14 that receives power from the hydrogen fuel supply system 12 to generate power, a hydrogen fuel supply system 12, and a fuel cell. And a heat exchanger 16 that exchanges heat between the two as main components.

The hydrogen fuel supply system 12 includes a pair of reactors 18. Each of the pair of reactors 18 is configured by disposing a reforming catalyst inside a cylindrically formed housing, and each of the supplied hydrocarbon gases (gasoline, methanol, natural gas, etc.) and A fuel gas containing hydrogen gas is generated (reforming reaction is performed) by catalyzing a reforming gas (water vapor, oxygen). The reforming reaction includes reactions represented by the following formulas (1) to (4). Therefore, the fuel gas obtained in the reforming process includes hydrogen (H ₂ ), carbon monoxide (CO), methane (CH ₄ ), cracked hydrocarbons, unreacted raw material hydrocarbons (C _x H _y ), etc. Incombustible gases such as combustible gas, carbon dioxide (CO ₂ ), and water (H ₂ O) are included.

_{C n H m + nH 2 O} → nCO + (n + m / 2) H 2 ... (1)
_{C n H m + n / 2O} 2 → nCO + m / 2H 2 ... (2)
CO + H ₂ O⇔CO ₂ + H ₂ (3)
CO + 3H ₂ ＣＨ CH ₄ + H ₂ O (4)
This reforming reaction is performed at a predetermined temperature or higher (in this embodiment, 700 ° C.). Each reactor 18 heats the catalyst by reacting the supplied regeneration gas and oxygen independently of the reforming reaction in order to increase the catalyst temperature lowered by the reforming reaction. A regeneration reaction for storing heat in the catalyst is performed. In this embodiment, the temperature of the catalyst in each reactor 18 is increased to a temperature at which the above-described reforming reaction can be performed by burning a regeneration gas (anode off gas described later). Accordingly, each reactor 18 is configured to selectively perform the reforming reaction and the regeneration reaction. The internal structure of each reactor 18 will be described later.

  The fuel cell 14 includes a fuel gas (a gas containing hydrogen, carbon monoxide, and unreacted hydrocarbon) obtained by the reforming reaction supplied from the hydrogen fuel supply system 12 to the anode electrode (hydrogen electrode), a cathode It is set as the structure which produces electric power by making the oxygen supplied to an electrode (oxygen electrode) react electrochemically. In this embodiment, the fuel cell 14 is a hydrogen separation membrane fuel cell (HMFC) in which a hydrogen separation membrane is provided between an anode electrode and a cathode electrode, and permeates the hydrogen separation membrane of the fuel gas. Only hydrogen thus reacted with oxygen at the cathode electrode (that is, only hydrogen gas in the fuel gas is used for power generation). For this reason, the anode off-gas of the fuel cell 14 is a combustible gas in which mainly carbon monoxide and hydrocarbon (which may include hydrogen) are mixed. On the other hand, the cathode off-gas of the fuel cell 14 is water (water vapor) generated by the reaction between oxygen and hydrogen and air containing oxygen.

  The flow of various gases will be described later. In the fuel cell system 10, the anode off gas is used as a regeneration gas for the reactor 18. In the fuel cell system 10, the water vapor and oxygen contained in the cathode off gas are reacted with the hydrocarbon gas, which is the reforming reaction gas, as shown in the above formulas (1) and (2). Furthermore, the fuel cell 14 is configured to be cooled with cooling air in order to keep its reaction temperature substantially constant (in this embodiment, a constant temperature between approximately 400 ° C. and 500 ° C.). The cooling air heated by cooling the fuel cell 14 is used as an oxygen-containing gas that is a combustion support gas for performing a regeneration reaction, that is, combustion air. Therefore, the fuel cell system 10 basically operates only by supplying a hydrocarbon raw material and cathode and cooling air.

  The heat exchanger 16 performs heat exchange between a fuel gas (700 ° C.) as a high-temperature gas supplied to the anode electrode of the fuel cell 14 and a cathode off-gas (400 ° C. to 500 ° C.) as a low-temperature gas. It is designed to improve the thermal efficiency of the system.

  The hydrogen fuel supply system 12 includes a flow path for reforming reaction gas (hydrocarbon gas, water vapor, oxygen) to a pair of reactors 18, a flow path for fuel gas generated by the reforming reaction, a regeneration gas, and a combustion gas. There is provided a switching device 20 for switching each flow path of air and the flow path of the regenerated exhaust gas. In the following description, when the two reactors 18 are distinguished, one reactor 18 shown on the upper side of each figure is referred to as a first reactor 18A, and the other reactor 18 is referred to as a second reactor 18B. .

  The switching device 20 is in a state in which the regeneration gas and oxygen are supplied to the second reactor 18B to perform the regeneration reaction during the period in which the reforming reaction gas is supplied to the first reactor 18A and the reforming reaction is performed. And a state in which the reforming reaction gas is supplied to the second reactor 18B and the reforming reaction is performed during the period in which the regeneration gas and oxygen are supplied to the first reactor 18A and the regeneration reaction is performed. It is configured. Hereinafter, a specific configuration example of the switching device 20 will be described. In the following description, the state (period) in which the reactor 18 is performing a reforming reaction may be referred to as a reforming step, and the state (period) in which the reactor 18 is performing a regeneration reaction may be referred to as a regeneration step.

  As shown in FIG. 5, the hydrogen fuel supply system 12 includes a raw material supply line 21, and a fuel pump 22 that supplies a liquid hydrocarbon raw material from a fuel tank (not shown) is disposed on the raw material supply line 21. Yes. An evaporator (vaporizer) 24 is disposed downstream of the fuel pump 22 in the raw material supply line 21. For example, the hydrocarbon raw material is evaporated by heat exchange with the exhaust gas of the fuel cell system 10. A mixer 26 is disposed downstream of the evaporator 24 in the raw material supply line 21. The mixer 26 mixes a hydrocarbon fuel and a cathode offgas (water vapor of formula (1) and oxygen of formula (2)), which will be described later, and discharges them downstream as a reforming reaction gas. Since the cathode off gas is at a high temperature, it is possible to adopt a configuration in which the evaporator 24 is not provided by adopting a configuration (injection) in which a liquid hydrocarbon raw material is injected into the mixer 26. Furthermore, between the evaporator 24 and the mixer 26, the valve | bulb V0 as a hydrocarbon raw material interruption | blocking means is arrange | positioned.

  An annular bridge line 28 is connected to the downstream end of the raw material supply line 21. In the bridge line 28, four valves V1A, V1B, V2B, and V2A are arranged in series in this order counterclockwise in each drawing. The downstream end of the raw material supply line 21 is connected between the valve V1A and the valve V1B in the bridge line 28. The upstream end of the exhaust line 30 is connected between the valve V2A and the valve V2B in the bridge line 28. An exhaust processor 32 is disposed on the exhaust line 30. The exhaust treatment device 32 is configured by incorporating an oxidation catalyst in the housing, and oxidizes (purifies) the regeneration gas that has not been burned by the regeneration reaction. The downstream end of the exhaust line 30 is an exhaust port 30A. An exhaust return line 34 branches from the exhaust line 30 downstream of the exhaust treatment device 32, and the exhaust return line 34 is connected to the mixer 26 so that exhaust gas can be introduced. A valve V3 is disposed in the exhaust return line 34. In the fuel cell system 10 according to this basic configuration, the exhaust treatment device 32 may not be provided.

  Further, the other end of the first line 36A, one end of which is connected to the first inlet / outlet 18C of the first reactor 18A, is connected between the valve V1A and the valve V2A in the bridge line 28. Furthermore, the other end of the second line 36 </ b> B having one end connected to the first inlet / outlet 18 </ b> D of the second reactor 18 </ b> B is connected between the valve V <b> 1 </ b> B and the valve V <b> 2 </ b> B in the bridge line 28. The first line 36A and the second line 36B are a first reactor 18A for performing a reforming reaction, a first reactor 18A for supplying a reforming reaction gas to the second reactor 18B, and a first reactor 18A for performing a regeneration reaction, respectively. The two-reactor 18B is selectively used for discharging regenerated exhaust gas.

  Furthermore, one end of a third line 38A is connected to the second inlet / outlet 18E disposed on the side opposite to the first inlet / outlet 18C (the side opposite to the gas flow direction) in the first reactor 18A. One end of the fourth line 38B is connected to the second entrance 18F arranged on the opposite side of the first entrance 18D in 18B. The other ends of the third line 38A and the fourth line 38B are connected to the annular bridge conduit 40, respectively. In this bridge line 40, four valves V5A, V5B, V6B, V6A are arranged in series in this order counterclockwise in each figure. The other end of the third line 38A is connected between the valve V5A and the valve V6A in the bridge conduit 40, and the other end of the fourth line 38B is between the valve V5B and the valve V6B in the bridge conduit 40. It is connected to the.

  One end of a fuel gas supply line 42 is connected between the valve V6A and the valve V6B in the bridge line 40. The other end of the fuel gas supply line 42 is connected to the hot gas inlet 16A of the heat exchanger 16 (fuel gas inlet 14A of the fuel cell 14). Further, one end of a regeneration gas introduction line 44 is connected between the valve V5A and the valve V5B in the bridge line 40. The other end of the regeneration gas introduction line 44 is connected to the anode offgas outlet 14 </ b> B of the fuel cell 14.

  An exhaust line 46 having a downstream end that is an exhaust port 46 </ b> A branches off from the fuel gas supply line 42, and an exhaust processor 48 is disposed on the exhaust line 46. The exhaust treatment device 48 is configured by incorporating an oxidation catalyst in the housing, and basically purifies exhaust gas (combustion gas) at the start-up of the hydrogen fuel supply system 12. A valve V <b> 7 is disposed upstream of the exhaust treatment device 48 in the exhaust line 46.

  Furthermore, the switching device 20 includes a water vapor supply line 50 that is connected to the mixer 26 at one end and supplies water vapor and oxygen to the mixer 26. The other end of the water vapor supply line 50 is connected to the low temperature gas outlet 16D of the heat exchanger 16, and the cathode off gas of the fuel cell 14 is supplied to the mixer 26. A valve V <b> 9 is disposed on the water vapor supply line 50.

  The switching device 20 has a combustion air supply line 52A having one end connected to the second inlet / outlet 18E in the first reactor 18A and a combustion air having one end connected to the second inlet / outlet 18F in the second reactor 18B. A supply line 52B is provided. A valve V4A is disposed on the combustion air supply line 52A, and a valve V4B is disposed on the combustion air supply line 52B. Each other end (upstream end) of each of the combustion air supply lines 52A and 52B is connected to the other end of a cooling air discharge line 54 that is connected to the cooling air outlet 14F of the fuel cell 14.

  An exhaust line 56 having a downstream end that is an exhaust port 56 </ b> A branches off from the cooling air discharge line 54, and a valve V <b> 8 is disposed on the exhaust line 56. The valve V8 is configured to have an arbitrary valve opening, and according to the valve opening, the exhaust amount by the exhaust line 56, that is, the combustion supplied to the reactor 18 through the combustion air supply lines 52A and 52B. The supply amount of working air can be adjusted.

  Further, the switching device 20 has one end branched from the third line 38A and the other end connected to a regeneration gas inlet 18G disposed on the second inlet / outlet 18E side of the cylindrical wall of the first reactor 18A. A regeneration gas line 55B, one end of which is branched from the fourth line 38B and the other end of which is connected to the regeneration gas inlet 18H disposed on the second inlet / outlet 18F side of the cylindrical wall of the second reactor 18B. It has. Between the branch portion 38C of the regeneration gas line 55A in the third line 38A and the first reactor 18A, a check valve CV1A for preventing gas inflow from the branch portion 38C side to the second inlet / outlet 18E is arranged. It is installed. Further, a check valve CV2A for preventing gas from flowing from the regeneration gas inlet 18G side to the branch portion 38C is disposed between the branch portion 38C and the regeneration gas inlet 18G in the regeneration gas line 55A. ing. Similarly, a check valve for preventing gas inflow from the branch portion 38D side to the second inlet / outlet 18F between the branch portion 38D of the regeneration gas line 55B in the fourth line 38B and the second reactor 18B. CV1B is disposed. Further, a check valve CV2B for preventing gas from flowing from the regeneration gas inlet 18H side to the branch portion 38D is disposed between the branch portion 38D and the regeneration gas inlet 18H in the regeneration gas line 55B. ing.

  As a result, the gas discharged from the first reactor 18A to the bridge line 40 side reaches the bridge line 40 via the second inlet / outlet 18E and the third line 38A (check valve CV1A). The gas (regeneration gas) flowing from the 40 side to the first reactor 18A side passes through the third line 38A, the regeneration gas line 55A (check valve CV2A), and the regeneration gas inlet 18G, and thus the first reactor 18A. It has come to reach. Similarly, the gas discharged from the second reactor 18B to the bridge line 40 side reaches the bridge line 40 via the second inlet / outlet 18F and the fourth line 38B (check valve CV1B). The gas flowing from the 40 side to the first reactor 18A side reaches the second reactor 18B via the fourth line 38B, the regeneration gas line 55B (check valve CV2B), and the regeneration gas inlet 18H. ing. For this reason, the fuel gas generated in the reforming process is discharged from the second inlet / outlet 18E, 18F, and the regeneration gas that serves as the fuel in the regeneration process is supplied from the combustion air supply lines 52A, 52B in the reactor 18 to the first. It is set as the structure supplied from the direction which cross | intersects the flow of the combustion air which goes to the entrance / exit 18C, 18D side. Therefore, the regeneration gas and the combustion air are not premixed upstream of the reactor 18.

  The switching device 20 described above switches the flow path of the reforming reaction gas (hydrocarbon gas, water vapor, oxygen) to the pair of reactors 18 according to the opening and closing of the valves V1A and V1B, and opens and closes the valves V6A and V6B. Accordingly, the flow path of the fuel gas generated by the reforming reaction is switched, the flow path of the regeneration gas (anode off gas) is switched according to the opening and closing of the valves V5A and V5B, and the combustion gas is switched according to the opening and closing of the valves V4A and V4B. The flow path of air (cooling air) is switched, and the flow path of the regenerated exhaust gas is switched according to the opening and closing of the valves V2A and V2B. Each valve is an electromagnetic valve, and is configured to open and close (valve V8 adjusts the valve opening) based on an operation signal from a control device 70 described later. The switching operation by switching the valve of the switching device 20, that is, the specific operation of the hydrogen fuel supply system 12 will be described later as the basic operation of the fuel cell system 10. Instead of the check valves CV1A, CV1B, CV2A, and CV2B described above, an electromagnetic on-off valve that opens and closes based on an operation signal of the control device 70 may be provided.

  The fuel gas inlet 14 A of the fuel cell 14 and the hot gas outlet 16 B of the heat exchanger 16 are connected by a fuel gas line 58. Thereby, the fuel gas inlet 14A of the fuel cell 14 has the reactor 18, the third line 38A or the fourth line 38B for performing the reforming process, the valve V6A or the valve V6B of the bridge line 40, the fuel gas supply line 42, The fuel gas that has passed through the high-temperature gas flow path and the fuel gas line 58 in the heat exchanger 16 is supplied. The fuel gas introduced into the fuel cell 14 from the fuel gas inlet 14A is supplied to the anode electrode, and as described above, only hydrogen gas is used for power generation, and the remaining combustible gas component is the anode off-gas as the anode of the fuel cell 14. The gas is discharged from the off-gas outlet 14B. The anode off gas is supplied to the reactor 18 as a regeneration gas through the regeneration gas introduction line 44, the valve V5A or the valve V5B, the third line 38A or the fourth line 38B.

  The cathode air inlet 14 </ b> C of the fuel cell 14 is connected to the other end of a cathode air supply line 62 having one end connected to the discharge side of the air pump 60. A valve V <b> 10 is disposed on the cathode air supply line 62. Air (oxygen) introduced into the fuel cell 14 from the cathode air inlet 14C is introduced into the cathode electrode and reacts with hydrogen that has permeated the hydrogen separation membrane as described above. Water vapor and unreacted air generated by this reaction are discharged from the cathode offgas outlet 14D as cathode offgas.

  The cathode offgas outlet 14 </ b> D of the fuel cell 14 and the low temperature gas inlet 16 </ b> C of the heat exchanger 16 are connected by a low temperature gas line 64. Therefore, the cathode offgas discharged from the cathode offgas outlet 14D is introduced into the mixer 26 through the low temperature gas line 64, the low temperature gas flow path in the heat exchanger 16, and the water vapor supply line 50, and the hydrocarbon raw material is mixed in the mixer 26. To be mixed with. This mixed gas is supplied to the reactor 18 as a reforming reaction gas through the raw material supply line 21, the valve V1A or the valve V1B of the bridge line 28, the first line 36A or the second line 36B.

  Further, the cooling air inlet 14 </ b> E of the fuel cell 14 is connected to the other end of a cooling air supply line 68 whose one end is connected to the discharge side of the air pump 66. A valve V <b> 11 is disposed on the cooling air supply line 68. The air introduced from the cooling air inlet 14E into the fuel cell 14 cools the fuel cell 14 while flowing through a cooling air passage (not shown) to keep the operating temperature at a substantially constant temperature. The cooling air after cooling the fuel cell 14 is discharged from the cooling air outlet 14F, and is used as combustion air for the regeneration process through the cooling air discharge line 54, the combustion air supply line 52A, or the combustion air supply line 52B. It is fed to the reactor 18.

  Regenerated exhaust gas (combustion gas) generated in the regeneration process is discharged out of the system from the exhaust port 30A through the first line 36A or the second line 36B, the valve V2A or valve V2B of the bridge line 28, and the exhaust line 30. It has become.

  Further, the fuel cell system 10 includes a control device 70. As shown in FIG. 6, the control device 70 includes each valve of the switching device 20 (valves V0, V1A, V1B, V2A, V2B, V3, V4A, V4B, V5A, V5B, V6A, V6B, V7, V8, V9). The valves V10 and V11 for supplying air to the fuel cell 14 are electrically connected to the fuel pump 22 and the air pumps 60 and 66, and the valves are opened and closed (the valve opening of the valve V8 is adjusted). ) And the operation and stop of each pump (control of the supply amount of fuel or air). The control device 70 is configured to perform operations as shown in the flowchart shown in FIG. This operation will be described together with the basic operation of the fuel cell system 10.

  Further, as shown in FIGS. 5 and 6, the fuel cell system 10 includes temperature sensors 72 </ b> A and 72 </ b> B as reforming capacity detection means disposed in the reactors 18 </ b> A and 18 </ b> B. As shown in FIG. 6, the temperature sensors 72 </ b> A and 72 </ b> B are electrically connected to the control device 70, and output a signal corresponding to the catalyst temperature in the corresponding reactor 18 to the control device 70. Yes.

  Furthermore, various types of vehicle information are input to the control device 70 of the fuel cell system 10 constituting the power supply system for the motor for driving the automobile. In this embodiment, as shown in FIG. 6, an accelerator pedal operation amount, a vehicle speed, a brake pedal operation amount, and the like are input to the control device 70 as vehicle information. For example, the control device 70 changes the discharge amount of the hydrocarbon raw material by the fuel pump 22 in accordance with the input operation amount of the accelerator pedal (mechanical accelerator opening, simple electric signal or the like). Yes. Moreover, these vehicle information is used for the control with respect to the rapid acceleration request | requirement mentioned later.

(basic action)
Next, basic operation of the fuel cell system 10 will be described. FIG. 8 is a system configuration diagram showing a state in which the first reactor 18A performs the reforming process and the second reactor 18B performs the regeneration process. In FIG. 9, the first reactor 18A includes the first reactor 18A. A state in which the second reactor 18B performs the reforming process while performing the regeneration process is shown in the system configuration diagram. In each figure showing the operation of the fuel cell system 10, the open valve is shown in white, the closed valve is shown in black, and the flow path in which the valve is closed and the flow of fluid is blocked is shown. Shown in imaginary lines.

  In the state shown in FIG. 8, the valves V0, V1A, V2B, V4B, V5B, V6A, V9, V10, and V11 are opened. On the other hand, the valves V1B, V2A, V4A, V5A, and V6B are closed. Thus, the hydrocarbon raw material reaches the mixer 26 through the raw material supply line 21 (valve V0), and is mixed with water vapor and air (oxygen) in the mixer 26 to become a reforming reaction gas. The reforming reaction gas discharged from the mixer 26 is supplied into the first reactor 18A via the bridge line 28 (valve V1A) and the first line 36A. In the first reactor 18A, a reforming reaction including the reactions of the above formulas (1) to (4) is performed by contact between the catalyst and the reforming reaction gas, and a fuel gas containing hydrogen, carbon monoxide and the like is generated. Is done.

  This fuel gas is introduced into the heat exchanger 16 through the third line 38A and the bridge line 40 (valve V6A), and is cooled by exchanging heat with the cathode off-gas which is the reforming gas in the heat exchanger 16. The At this time, since the pressure in the first reactor 18A upstream of the fuel gas is higher than that on the branch portion 38C side, the gas backflow from the branch portion 38C to the first reactor 18A is blocked by the check valve CV2A. Yes. The fuel gas cooled by the heat exchanger 16 is introduced into the anode electrode in the fuel cell 14 through the fuel gas line 58 and the fuel gas inlet 14A of the fuel cell 14. The fuel cell 14 is constantly supplied with air, that is, oxygen, to the cathode electrode through the cathode air supply line 62 and the cathode air inlet 14C. From the anode electrode, only hydrogen gas becomes protons through the hydrogen separation membrane and moves to the cathode electrode, and electric power is generated by a reaction between this hydrogen and oxygen supplied to the cathode electrode. Further, the cooling air is constantly supplied to the fuel cell 14 through the cooling air supply line 68 and the cooling air inlet 14E, and the operation temperature is maintained at a substantially constant temperature of 400 ° C to 500 ° C.

  The cathode offgas containing water vapor and oxygen discharged from the cathode offgas outlet 14D of the fuel cell 14 is introduced into the low temperature gas passage of the heat exchanger 16 and exchanges heat with the fuel gas introduced into the anode electrode as described above. . Thereafter, the cathode off-gas is introduced into the mixer 26 through the steam supply line 50, mixed with the hydrocarbon raw material as described above to become a reforming reaction gas, and is introduced into the first reactor 18A.

  The anode off gas containing carbon monoxide and hydrocarbon raw material discharged from the anode off gas outlet 14B of the fuel cell 14 is a regeneration gas introduction line 44, a bridge line 40 (valve V5B), a fourth line 38B, and a regeneration gas line. 55B is introduced into the second reactor 18B from the regeneration gas inlet 18H as a regeneration gas. At this time, since the upstream side of the regeneration gas has a higher pressure on the side of the branch portion 38D than in the second reactor 18B, the backflow of gas from the second reactor 18B to the branch portion 38D is blocked by the check valve CV1B. Has been. On the other hand, the cooling air discharged from the cooling air outlet 14F of the fuel cell 14 passes through the cooling air discharge line 54 and the combustion air supply line 52B (valve V4B) as the combustion air from the second inlet / outlet 18F to the second. Introduced into reactor 18B. In this 2nd reactor 18B, the regeneration gas which is a combustible gas which contacted the catalyst with the combustion air combusts. Thereby, the catalyst temperature of the second reactor 18B rises to a temperature at which the reforming reaction can be performed, and heat storage necessary for the reforming is performed. Regenerated exhaust gas, which is a combustion gas generated by this combustion, is discharged out of the system through the second line 36B, the bridge line 28 (valve V2B), and the exhaust line 30.

  If the control device 70 of the fuel cell system 10 determines that it is not time to switch the first reactor 18A from the reforming process to the regeneration process in step S10 of the flowchart shown in FIG. 7, the process proceeds to step S16 and the valve as described above. V1A, V2B, V4B, V5B, and V6A are opened, and the valves V1B, V2A, V4A, V5A, and V6B are kept closed. On the other hand, when the catalyst temperature of the first reactor 18A in which the reforming reaction has been performed decreases and the reforming reaction cannot be maintained (the control parameter such as elapse of a predetermined time, the catalyst temperature falls below a threshold value), the control device 70 The first reactor 18A is switched from the reforming process to the regeneration process by switching the switching device 20. At the same time as this switching, the second reactor 18B is switched from the regeneration process to the reforming process. That is, when it is determined that it is time to switch the first reactor 18A from the reforming process to the regeneration process, the control device 70 proceeds to step S12, closes the valves V1A, V2B, V4B, V5B, V6A and closes the valve V1B. , V2A, V4A, V5A, V6B are opened. Thereby, the fuel cell system 10 switches from the state shown in FIG. 8 to the state shown in FIG.

  Explaining the difference from the state of FIG. 8, the reforming reaction gas discharged from the mixer 26 is supplied into the second reactor 18B via the bridge line 28 (valve V1B) and the second line 36B. The reforming reaction is performed by contact with the catalyst, and fuel gas containing hydrogen and carbon monoxide is generated. This fuel gas is introduced into the heat exchanger 16 and the anode electrode in the fuel cell 14 through the fourth line 38B and the bridge line 40 (valve V6B). The cathode off-gas discharged from the fuel cell 14 passes through the heat exchanger 16 and is then introduced into the mixer 26, mixed with the hydrocarbon raw material as described above to become a reforming reaction gas, and introduced into the second reactor 18B. Is done.

  The anode off gas discharged from the fuel cell 14 passes through the regeneration gas inlet 18G as the regeneration gas through the regeneration gas introduction line 44, the bridge line 40 (valve V5A), the third line 38A, and the regeneration gas line 55A. Introduced into the reactor 18A. On the other hand, the cooling air discharged from the fuel cell 14 is introduced into the first reactor 18A from the second inlet / outlet 18E as combustion air through the cooling air discharge line 54 and the combustion air supply line 52A (valve V4A). . In the first reactor 18A, combustion of regeneration gas that has come into contact with the catalyst together with combustion air raises the catalyst temperature to a temperature at which a reforming reaction can be performed, and heat storage necessary for reforming is performed. Regenerated exhaust gas, which is combustion gas generated by this combustion, is discharged out of the system through the first line 36 </ b> A, the bridge line 28 (valve V <b> 2 </ b> A), and the exhaust line 30.

  Further, in step S14 of the flowchart shown in FIG. 7, the control device 70 is not the timing for switching the second reactor 18B from the reforming process to the regeneration process (the timing for switching the first reactor 18A from the regeneration replacement to the reforming process). When the determination is made, the process returns to step S12, and the valves V1B, V2A, V4A, V5A, and V6B are opened and the valves V1A, V2B, V4B, V5B, and V6A are closed as described above. On the other hand, when determining that it is time to switch the second reactor 18B from the reforming step to the regeneration step, the control device 70 proceeds to step S16, closes the valves V1B, V2A, V4A, V5A, V6B and closes the valve V1A. , V2B, V4B, V5B, V6A are opened. Thereby, the fuel cell system 10 switches from the state shown in FIG. 9 to the state shown in FIG. Therefore, the valve open / close state of step S12 is the second state in the present invention for the first reactor 18A and the first state for the second reactor 18B, and the valve open / close state of S16 is the first reaction. A first state for the reactor 18A and a second state for the second reactor 18B.

  The control device 70 controls the switching between the reforming process and the regeneration process of each reactor 18 and supplies the fuel gas according to the load of the fuel cell 14 (for the reactor 18 that performs the reforming process). The control for adjusting the feed rate) and the control for maintaining the catalytic combustion temperature during the regeneration step within a predetermined temperature range are performed. In this embodiment, the control device 70 sets the combustion air (after cooling of the fuel cell 14) so that the excess air ratio (combustion stoichiometry) in the regeneration process becomes a preset control target (1.1 in this embodiment). The catalyst combustion temperature is kept at 800 ° C. to 900 ° C. by controlling the supply amount of the air) to the reactor 18, that is, the valve opening of the valve V8 and the discharge amount of the air pump 66.

  As described above, in the fuel cell system 10, each reactor 18 is configured to generate fuel gas intermittently (batch-like) alternately and alternately with the reforming step and the regeneration step, but continuously with respect to the fuel cell 14. The structure which can supply fuel gas and can generate electric power continuously and stably is realized. In the fuel cell system 10, since the fuel cell 14 separates only hydrogen from the fuel gas by the hydrogen separation membrane and uses it for power generation, and the remaining gas is used as fuel for the regeneration process, the fuel gas obtained in the reforming process There is no need to perform a shift reaction in which carbon monoxide is further reacted with water to obtain hydrogen and carbon dioxide. Although the shift reaction has a slow reaction rate and requires a large reactor, since it is not necessary to perform this shift reaction, the fuel cell system 10 can be made compact.

(Control for sudden acceleration request)
In the fuel cell system 10 applied to an automobile, the control device 70 determines that there is an acceleration request (hereinafter referred to as a rapid acceleration request) at or above a predetermined acceleration of the automobile based on the operation amount (change) of the accelerator pedal. In this case, the discharge amount of the hydrocarbon raw material by the fuel pump 22 is increased. As a result, the amount of fuel gas generated by the reactor 18 performing the reforming process increases, and the amount of power generated by the fuel cell 14 increases, so that the automobile can be accelerated. Then, the control device 70 switches the switching device 20 so that the reactor 18 performing the reforming process cannot be switched from the reforming process to the regeneration process during the period corresponding to the rapid acceleration request of the automobile. It comes to perform control.

  This control will be described with reference to the flowchart shown in FIG. 2 and the timing chart shown in FIG. In the timing chart shown in FIG. 1, the process switching timing chart of each reactor 18 indicates the reforming process of each reactor 18A, 18B by a solid line, and the regeneration process by a broken line.

  The control device 70 determines whether or not there is a rapid acceleration request in step S20 of the flowchart shown in FIG. Specifically, the control device 70 sets an increase in which the rate of increase in the amount of hydrocarbon raw material per unit time to be supplied to the reactor 18 in the reforming process is set based on the operation amount of the accelerator pedal and vehicle speed information. If the rate is exceeded, it is determined that there is a request for rapid acceleration. If it is determined that there is no sudden acceleration request, the process proceeds to step S32, and the basic operation shown in the flowchart of FIG. 7 is maintained. If it is determined in step S20 that the rapid acceleration request has been made, the control device 70 proceeds to step S22, and increases the discharge amount of the fuel pump 22 so that the supply amount of the hydrocarbon raw material increases in response to the rapid acceleration request (FIG. 1 timing chart).

  The control device 70 then proceeds to step S24, and reaches the switching timing T1 (see FIG. 1) for switching to the regeneration step in the basic operation of the reactor 18 performing the reforming step during the period of the rapid acceleration request. Is high). Specifically, when the set time has elapsed since the start of the reforming process (when the rapid acceleration request is made immediately before the switching timing T1), the control device 70 reaches the switching timing T1 during the rapid acceleration. to decide. In this embodiment, the set time is set as 70% or more and less than 100% of the modification process maintenance time (for example, 10 seconds) in the basic operation. In addition, instead of the determination based on the set time, for example, when a signal corresponding to that the catalyst temperature of the reactor 18 performing the reforming process is lower than the set temperature is input from the temperature sensor 72A or the temperature sensor 72B. In addition, it may be determined that the switching timing T1 is reached during the rapid acceleration period. Further, in step S24, it may be determined whether or not the switching timing T1 has actually been reached during the period in which the rapid acceleration request is maintained (whether the determination in steps S10 and S14 is successful).

  The control device 70 switches from the reforming step to the regeneration step of the reactor 18 during the period when the switching timing T1 is reached during the rapid acceleration in step S24, that is, when the basic operation is maintained, the rapid acceleration request is maintained. If this is the case, the process proceeds to step S26, and the reforming process is maintained without switching the reactor 18 to the regeneration process at the switching timing T1. In the example shown in the timing chart of FIG. 1, the second reactor 18B that has been performing the reforming process before the sudden acceleration request is changed to the regeneration process at the switching timing T1 immediately after the sudden acceleration request is started. Maintain the quality process. Further, the first reactor 18A is maintained in the regeneration process. That is, the switching device 20 is maintained in the state shown in FIG. 9 without switching from the state of FIG. 9 to the state of FIG.

  On the other hand, if the control device 70 determines in step S24 that the switching timing T1 is not reached during the rapid acceleration (the probability of reaching the switching timing T1 during the rapid acceleration is low), the control device 70 proceeds to step S32, and the flowchart of FIG. The basic operation shown in is maintained. That is, in this case, at the switching timing T1, the second reactor 18B is switched to the regeneration process and the first reactor 18A is switched from the regeneration process to the reforming process.

  Subsequent to step S26, the control device 70 proceeds to step S28 and maintains whether or not the rapid acceleration request has been canceled, that is, the above-described increase rate of the hydrocarbon fuel to be supplied exceeds the set increase rate. It is determined based on the operation amount of the accelerator pedal and vehicle speed information. When it is determined that the rapid acceleration request has been canceled, the control device 70 proceeds to step S30, switches one reactor 18 that has been performing the reforming process to the regeneration process, and reforms the other reactor 18. Switch to the process. In the example shown in the timing chart of FIG. 1, the second reactor 18B is switched to the regeneration process and the first reactor 18A is switched from the regeneration process to the reforming process at the timing of the sudden acceleration request cancellation. Thereafter, the control device 70 proceeds to step S32 and returns to a state in which the basic operation (switching between the reforming process and the regeneration process of each reactor at the switching timing) is performed.

  On the other hand, if it is determined in step S26 that the rapid acceleration request has not been canceled, the control device 70 proceeds to step S34, and the amount of heat for maintaining the reforming process of the reactor 18 that is performing the reforming process ( Hereinafter, it is determined whether the reforming heat amount is insufficient. Specifically, in the example shown in the timing chart of FIG. 1, the control device 70 has a preset lower limit temperature (for example, a signal value from the temperature sensor 72B provided in the second reactor 18B performing the reforming process). , 700 ° C.), it is determined that the amount of reforming heat is insufficient.

  If the controller 70 determines in step S34 that the amount of reforming heat is not insufficient, the controller 70 returns to step S26. On the other hand, if the controller 70 determines in step S34 that the amount of reforming heat is insufficient, the control device 70 proceeds to step S36 and performs heat absorption assistance for the reactor 18 performing the reforming process. In this embodiment, the control device 70 increases the air discharge amount of the air pump 60 that constitutes the heating means in the present invention, and the oxidation reaction in the reactor 18 performing the reforming reaction (the above equation (2) Or the oxidation of carbon monoxide), in other words, the partial dispersion ratio in the reactor 18 is improved. The heat generated by the oxidation reaction assists the endotherm of the reforming reaction (of which, endothermic reaction). Thereby, it is possible to maintain the reforming step, that is, supply of hydrogen (increase in supply amount) to the fuel cell 14 beyond the switching timing T1 described above.

  After executing (starting) step S36, the control device 70 returns to step S26 and maintains the reforming step of the reactor 18 that performs the reforming step until it is determined in step S28 that the rapid acceleration request has been canceled. .

  Here, in the hydrogen fuel supply system 12, when it is determined that the switching timing T1 from the reforming process to the regeneration process of the reactor 18 performing the reforming process is reached during the period when the rapid acceleration is requested. Since the reactor 18 is maintained in the reforming process without switching from the reforming process to the regeneration process at the switching timing, it is possible to prevent the hydrogen supply amount to the fuel cell 14 from temporarily decreasing during the rapid acceleration of the automobile. The That is, in the hydrogen fuel supply system 12, regeneration residual gas composed of regeneration gas, regeneration exhaust gas, combustion air, etc. remains in the reactor 18 immediately after switching to the reforming process. Since the generated fuel gas is pushed out and supplied to the fuel cell 14, the hydrogen concentration in the gas supplied to the fuel cell 14 is temporarily (immediately) immediately after the switching. This prevents a decrease in the hydrogen concentration in the gas supplied to the fuel cell 14 during rapid acceleration. For this reason, acceleration delay and deterioration in driving sensibility such as a temporary decrease in motor output due to a decrease in the hydrogen supply amount despite the increase in the amount of operation of the accelerator pedal for acceleration to the driver of the car. It is prevented or suppressed from occurring. In addition, acceleration shock caused by supplying high-concentration hydrogen to the fuel cell 14 after the occurrence of acceleration delay is prevented or suppressed.

  Further, in the hydrogen fuel supply system 12, when the hydrogen generation capability of the reactor 18 that is maintaining the reforming process is reduced during the period in which the rapid acceleration request is maintained, in other words, the catalyst of the reactor 18 is reduced. When the heat storage amount decreases, the heat absorption assisting operation is performed, so that the reforming process can be maintained for a long time in the reactor 18 in which the temperature is not increased and the heat storage is not performed in the regeneration process. For this reason, control (configuration) that does not cause the reactor 18 to switch from the reforming process to the regeneration process, that is, to temporarily reduce the hydrogen supply amount to the fuel cell 14, during the entire period of rapid acceleration of the automobile is realized. ing.

  As described above, the hydrogen fuel supply system 12 according to the first embodiment includes the plurality of reactors 18 and can satisfactorily follow the demand for increasing the hydrogen supply amount.

(Preparation for sudden acceleration request)
Further, in the fuel cell system 10 applied to an automobile, the control device 70 has a deceleration request (hereinafter referred to as a sudden deceleration request) at or above a predetermined deceleration of the automobile based on the operation amount (change) of the brake pedal. If it is determined that the fuel has been discharged, the discharge amount of the hydrocarbon raw material from the fuel pump 22 is decreased. As a result, the amount of fuel gas generated by the reactor 18 performing the reforming process is reduced, and the amount of power generated by the fuel cell 14 is reduced. When there is a request for rapid deceleration of the automobile, the control device 70 performs control to switch the switching device 20 in preparation for the next acceleration in a predetermined case.

  This control will be described with reference to the flowchart shown in FIG. 4 and the timing chart shown in FIG. In the timing chart shown in FIG. 3, the process switching timing chart of each reactor 18 shows the reforming process of each reactor 18A, 18B by a solid line, and the regeneration process by a broken line.

  The control device 70 determines whether or not there is a sudden deceleration request in step S40 of the flowchart shown in FIG. Specifically, the control device 70 is a reduction in which a reduction rate of the amount of hydrocarbon raw material per unit time to be supplied to the reactor 18 in the reforming process is set based on the operation amount of the brake pedal and vehicle speed information. If the rate is exceeded, it is determined that there is a sudden deceleration request. If it is determined that there is no sudden deceleration request, the process proceeds to step S48, and the basic operation shown in the flowchart of FIG. 7 is maintained. If it is determined in step S40 that a rapid deceleration request has been made, the control device 70 proceeds to step S42 and reduces the discharge amount of the fuel pump 22 so that the supply amount of the hydrocarbon raw material is reduced in response to the sudden deceleration request. (Refer to the timing chart of FIG. 3).

  The control device 70 then proceeds to step S44, and during the rapid deceleration request period, the time until the switching timing T2 to the reforming step in the basic operation of the reactor 18 performing the regeneration step is equal to or shorter than a predetermined time. Determine whether or not. Specifically, when the set time has elapsed since the start of the regeneration process (when a sudden deceleration request is made immediately before or near the switching timing T2), the control device 70 sets the time until the switching timing T2 to a predetermined time. It is determined that: In this embodiment, the set time is set as 70% or more and less than 100% of the maintenance time (for example, 10 seconds) of the reproduction process in the basic operation. In addition, instead of the determination based on the set time, for example, when the signal from the temperature sensor 72A or the temperature sensor 72B corresponds to that the reactor 18 performing the regeneration process has completed sufficient temperature increase and heat storage. The time until the switching timing T2 may be determined to be a predetermined time or less.

  If the control device 70 determines in step S44 that the time from the sudden deceleration request start to the switching timing T2 exceeds the predetermined time, the control device 70 proceeds to step S48 and maintains the basic operation shown in the flowchart of FIG. In the example shown in the timing chart of FIG. 3, at the switching timing T2, the second reactor 18B is switched to the regeneration process and the first reactor 18A is switched from the regeneration process to the reforming process.

  On the other hand, when the control device 70 determines in step S44 that the time from the start of the rapid deceleration request to the switching timing T2 exceeds the predetermined time, the control device 70 proceeds to step S46 and performs the reforming process before reaching the switching timing T2. One of the reactors 18 being operated is switched to the regeneration process, and the other reactor 18 is switched from the regeneration process to the reforming process. In the example shown in the timing chart of FIG. 3, the second reactor 18B is switched from the reforming step to the regeneration step, and the first reactor 18A is switched from the regeneration step to the reforming step. Thereafter, the control device 70 proceeds to step S48 and returns to a state in which the basic operation (switching between the reforming process and the regeneration process of each reactor at the switching timing) is performed.

  Here, in the hydrogen fuel supply system 12, when the switching timing T2 is reached within a predetermined time after the rapid deceleration request is made, the reactor 18 that has been performing the regeneration process before reaching the switching timing T2 is actively used. By switching to the reforming step, preparation for reducing the probability of executing the control shown in the flowchart of FIG. 2 for the next sudden acceleration request is made. Specifically, in an automobile, a rapid acceleration request is often made immediately after sudden deceleration. Therefore, the reactor 18 that has undergone sufficient catalyst regeneration (catalyst temperature increase and heat storage) in the regeneration process is modified. By switching to the quality process, the heat retention amount and temperature level of the heat storage reactor 18 (reforming side) are reset to the initial state (fresh state) immediately after switching.

  Therefore, for example, when a sudden acceleration request is made at timing T3 between the input of the sudden deceleration request shown in FIG. 3 and the switching timing T2, the sudden acceleration request is made without performing the control shown in the flowchart of FIG. Can respond. That is, by performing this control, the execution frequency of the control shown in the flowchart of FIG. 2 can be reduced. Along with this, the frequency (probability) of performing the heat absorption assistance (step S36) of the control of FIG. 2 is reduced, so that the efficiency of the entire hydrogen fuel supply system 12 is good.

(Other embodiments)
Next, another embodiment of the present invention will be described. Note that components and portions that are basically the same as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

  FIG. 10 shows a system configuration diagram of a fuel cell system 80 including a hydrogen fuel supply system 82 according to the second embodiment. As shown in this figure, the hydrogen fuel supply system 82 includes a switching device 84 instead of the switching device 20. The switching device 84 includes a cathode offgas exhaust line 86 branched from the water vapor supply line 50, and the downstream end of the cathode offgas exhaust line 86 is an exhaust port 86A. The cathode offgas exhaust line 86 is provided with a valve V12. Similarly to the valve V8, the valve V12 is configured to be able to take an arbitrary valve opening based on a control signal from the control device 70, and according to the valve opening, the exhaust amount by the cathode offgas exhaust line 86 is set. The supply amount of water vapor and air (oxygen) to the reforming process can be adjusted. This valve | bulb V12 comprises the heating means in this invention.

  A portion different from the hydrogen fuel supply system 12 in the operation of the hydrogen fuel supply system 82 will be described. In the hydrogen fuel supply system 82, the controller 70 controls the valve opening degree of the valve V12 so that the amount of water vapor required by the reforming process is supplied to the reactor 18. In this hydrogen fuel supply system 82, when the process proceeds to step S36 in the flowchart of FIG. 2, the control device 70 reduces the valve opening of the valve V12 before increasing the discharge amount of the air pump 60, so that the water vapor supply line 50 The flow rate is increased to promote the oxidation reaction (exothermic reaction) in the reactor 18 performing the reforming process, thereby assisting the shortage of the reforming heat amount. At this time, the amount of water vapor supplied to the reactor 18 that is performing the reforming process also increases, so that the amount of hydrogen generated by the reforming reaction (the reactions of the above formulas (1) and (3)) increases. The control after the valve V12 is fully closed is the same as in the first embodiment.

  Other functions and effects of the hydrogen fuel supply system 82 are the same as those of the hydrogen fuel supply system 12. Therefore, the hydrogen fuel supply system 82 also includes a plurality of reactors 18 and can satisfactorily follow the demand for increasing the hydrogen supply amount.

  FIG. 11 shows a system configuration diagram of a fuel cell system 90 including a hydrogen fuel supply system 92 according to the third embodiment. As shown in this figure, the hydrogen fuel supply system 92 includes heaters 94A and 94B as heating means for heating each reactor 18. The heaters 94A and 94B are electric heaters, and energization (ON / OFF) with a battery (not shown) is controlled by the control device 70. In this embodiment, the battery is not a hybrid system battery that supplies a drive current to a motor that is a drive source of an automobile, but a battery for driving auxiliary devices.

  A different part from the hydrogen fuel supply system 12 in the operation of the hydrogen fuel supply system 92 will be described. In the hydrogen fuel supply system 92, when the basic operation described above is performed, the heaters 94A and 94B are not energized, and each reactor 18 performs the reforming process by the heat stored in the regeneration process. In the hydrogen fuel supply system 82, when the process proceeds to step S36 in the flowchart of FIG. 2, the control device 70 does not increase the discharge amount of the air pump 60, and the heater 94A of the reactor 18 performing the reforming process or The heater 94B is energized, and the heat generated by the heater is used to assist heat absorption in the reforming process, and the reforming process is maintained.

  Other functions and effects of the hydrogen fuel supply system 92 are the same as those of the hydrogen fuel supply system 12. Therefore, the hydrogen fuel supply system 92 also includes the plurality of reactors 18 and can follow the demand for an increase in the hydrogen supply amount satisfactorily.

  In each of the above embodiments, an example in which it is determined whether or not the reforming heat quantity of the reactor 18 is insufficient based on the output signals of the temperature sensors 72A and 72B has been shown, but the present invention is not limited thereto. For example, it may be determined whether or not the reforming heat amount of the reactor 18 is insufficient based on the output of a calorimeter provided in place of the temperature sensors 72A and 72B.

  Moreover, in each said embodiment, the two reactors 18 are provided, the switching timing from the reforming process of one reactor 18 to the regeneration process, and the switching timing of the other reactor 18 from the regeneration process to the reforming process. However, the present invention is not limited to this. For example, three or more reactors 18 may be provided, and two or more reactors 18 may be reformed together. The switching device 20 may be switched so that there is a period during which the process is performed (set to the first state).

  Furthermore, in each of the above-described embodiments, the example in which the heat absorption assistance is performed in step S36 of the control shown in FIG. 2 has been described. However, the present invention is not limited to this. Anyway.

It is a timing chart of control corresponding to sudden acceleration by the control device which constitutes the hydrogen gas supply system concerning a 1st embodiment of the present invention. It is a flowchart of the rapid acceleration response control by the control apparatus which comprises the hydrogen gas supply system which concerns on the 1st Embodiment of this invention. It is a timing chart of control corresponding to sudden deceleration by the control device which constitutes the hydrogen gas supply system concerning a 1st embodiment of the present invention. It is a flowchart of the control corresponding to sudden deceleration by the control apparatus which comprises the hydrogen gas supply system which concerns on the 1st Embodiment of this invention. 1 is a system configuration diagram of a fuel cell system to which a hydrogen gas supply system according to a first embodiment of the present invention is applied. It is a block diagram which shows schematic structure of the control apparatus which comprises the hydrogen gas supply system which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the basic control flow of the control apparatus which comprises the hydrogen gas supply system which concerns on the 1st Embodiment of this invention. It is a system block diagram which shows one (reforming process of a 1st reactor) among the basic operations of the fuel cell system which concerns on the 1st Embodiment of this invention. It is a system block diagram which shows the other (the regeneration process of a 1st reactor) among the basic operations of the fuel cell system which concerns on the 1st Embodiment of this invention. It is a system block diagram of the fuel cell system with which the hydrogen gas supply system which concerns on the 2nd Embodiment of this invention was applied. It is a system block diagram of the fuel cell system to which the hydrogen gas supply system which concerns on the 3rd Embodiment of this invention was applied.

Explanation of symbols

12 Hydrogen fuel supply system 18 Reactor 20 Switching device 60 Air pump (heating means)
70 Controller 72A / 72B Temperature sensor (reforming ability detecting means)
94A / 94B Heater (heating means)
V12 valve (heating means)

Claims (5)

A reforming step of generating a fuel gas containing hydrogen from the supplied raw material, and a regeneration step of burning the supplied regeneration gas to a temperature capable of reforming by reducing the temperature reduced by the reforming step. A plurality of reactors that can be switched to perform;
A switching device for switching between a first state in which the fuel gas is discharged while supplying the raw material to the reactor and a second state in which the regeneration exhaust gas is discharged while supplying the regeneration gas to the reactor When,
The switching timing of the at least two of the reactors from the first state to the second state is made different and the first state and the second state are alternately generated in the plurality of reactors, respectively. In addition, when the time until the switching timing of the one reactor from the first state to the second state is equal to or less than a predetermined time, an increase request for the predetermined amount or the predetermined increase rate of the fuel gas supply amount is made. The switching device so that the supply amount of the raw material is increased while the one reactor is maintained in the first state without switching to the second state at the switching timing. A control device for switching between,
A hydrogen fuel supply system. A reforming step of generating a fuel gas containing hydrogen from the supplied raw material, and a regeneration step of burning the supplied regeneration gas to a temperature capable of reforming by reducing the temperature reduced by the reforming step. A plurality of reactors that can be switched to perform;
Switching for switching between a first state in which the fuel gas is discharged while supplying the raw material to each reactor and a second state in which the regeneration exhaust gas is discharged while supplying the regeneration gas to the reactor Equipment,
The switching timing of the at least two of the reactors from the first state to the second state is made different and the first state and the second state are alternately generated in the plurality of reactors, respectively. And without causing the switching of one of the reactors from the first state to the second state during a period when the fuel gas supply amount is requested to increase more than a predetermined amount or a predetermined increase rate, A control device that switches the switching device so that the amount of the raw material supplied to the one reactor is increased;
A hydrogen fuel supply system. Reforming capacity detecting means for outputting a signal corresponding to the temperature or heat quantity of each reactor to the control device;
Heating means capable of heating each of the reactors,
When the control device determines that the heat retention amount of the reactor maintained in the first state is lower than a set heat amount based on the output signal of the reforming capacity detection means, the heating of the reactor The hydrogen fuel supply system according to claim 1 or 2, wherein the means is operated.   The control device has a predetermined amount or a predetermined reduction rate of the fuel gas supply amount at a time when the time from the first state to the second state of one reactor is not more than a predetermined time. The switching device is switched so that another reactor is switched from the second state to the first state before the switching timing when the reduction request is made. The hydrogen fuel supply system according to any one of the preceding claims. A reforming step of generating a fuel gas containing hydrogen from the supplied raw material, and a regeneration step of burning the supplied regeneration gas to a temperature capable of reforming by reducing the temperature reduced by the reforming step. A plurality of reactors that can be switched to perform;
Switching for switching between a first state in which the fuel gas is discharged while supplying the raw material to each reactor and a second state in which the regeneration exhaust gas is discharged while supplying the regeneration gas to the reactor Equipment,
Causing each of the reactors to alternately generate the first state and the second state so that at least two of the reactors have different timings for switching from the first state to the second state, and 1 When a request for reduction of the fuel gas supply amount by a predetermined amount or a predetermined reduction rate is made at a time when the time from the first state to the second state of the two reactors is a predetermined time or less And a control device for switching the switching device so that another reactor is switched from the second state to the first state before the switching timing,
A hydrogen fuel supply system.

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