JP3852362B2 - Fuel gas control device for fuel cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel gas control device for a fuel cell, and more particularly to a fuel gas control device for a fuel cell suitable for a sudden increase in output current.
[0002]
[Prior art]
Conventionally, for example, Japanese Patent Application Laid-Open No. 7-263005 discloses a fuel gas supplied to a fuel cell.
[0003]
This is a fuel having a reaction electrode that is supplied with fuel gas to generate a reaction gas, a reaction electrode outlet valve through which surplus gas passes, and an exhaust gas branching portion that is disposed in the subsequent stage and communicates with the gas discharge valve. The present invention relates to a pressure control device for a reaction electrode gas circulation system of a battery power generation system. Then, the controller performs a multivariable control calculation so that the detected values of the reaction electrode pressure and the exhaust gas branching section pressure coincide with the respective target values, and calculates and outputs the opening of each valve. As a result, the pressure of the reaction electrode in the reaction electrode gas circulation system of the fuel cell power generation system and the pressure of the exhaust gas branching section are matched to the target values without control delay, and the fuel cell is operated with high efficiency. is there.
[0004]
[Problems to be solved by the invention]
However, in the above conventional example, the pressure of the reaction electrode and the pressure of the exhaust gas branching portion in the reaction electrode gas circulation system of the fuel cell power generation system are matched to the target value without control delay, and the fuel cell is stably operated with high efficiency. Therefore, the fuel cell of a moving body such as a fuel cell vehicle that is operated to increase or decrease the output in response to the torque request has problems such as a shortage of fuel gas supplied when the torque request increases. It was difficult to apply.
[0005]
Further, in the above conventional example, the number of parts such as the fuel electrode pressure gauge and the exhaust gas pressure gauge, and the outlet valve and the exhaust gas valve are large, and the volume and weight of the system increase. On the other hand, the cost increases due to the large number of parts.
[0006]
Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a simple fuel gas control device for a fuel cell that can suitably cope with an increase in torque demand.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a fuel cell that generates power by receiving fuel gas and oxidant gas supplied to a fuel electrode and an oxidant electrode, a fuel supply passage that supplies fuel gas to the fuel cell, and the fuel cell. A recirculation passage for recirculating surplus gas from the fuel supply passage to the fuel supply passage, a fuel gas flow rate adjusting means capable of restricting a flow of the fuel gas recirculating through the recirculation passage, and a power generation state of the fuel cell. A power generation state detection unit for detecting, a power generation state correction unit that calculates a flow rate restriction ratio of the fuel gas flow rate adjustment unit based on a power generation state input from the power generation state detection unit, and outputs the ratio to the fuel gas flow rate adjustment unit; It is characterized by having.
[0008]
The fuel gas flow rate adjusting means can be constituted by a valve whose opening degree can be adjusted, a pump which can adjust the passing flow rate, and the like. Further, the power generation state detection means may be, for example, an output voltmeter attached to the fuel cell. The power generation state correction unit determines the target value of the fuel gas flow rate adjusting means according to the output voltage or the like when the load connected to the fuel cell increases and the output current rapidly increases and the supply gas becomes insufficient and the power generation state decreases. Thus, the flow of the fuel gas is restricted and the surplus fuel gas is calculated so as to remain in the stack.
[0009]
According to a second aspect, in the first aspect, the fuel gas flow rate adjusting means is a valve that can be set to an arbitrary opening degree.
[0010]
According to a third invention, in the first invention, the power generation state detection means is a voltmeter that detects a power generation voltage of the fuel cell, and the power generation state correction unit is based on a decrease amount of the voltage value of the voltmeter. The valve opening is calculated.
[0011]
According to a fourth invention, in the first to third inventions, the fuel gas control device of the fuel cell includes a required power detection unit that detects a required power to the fuel cell; Rapid increase in required power An operating state detection unit that detects the flow rate, a power rapid increase correction unit that obtains a flow rate restriction ratio of the fuel gas flow rate control means based on a change amount of the required power that rapidly increases when the required power rapidly increases, and the power generation state correction unit Either the calculated flow rate restriction rate or the flow rate restriction rate obtained by the power surge correction unit Smaller percentage Select Out And an opening selection unit that applies force.
[0012]
According to a fifth aspect based on the fourth aspect, the operating state detection unit change of On the basis of the Judgment of power surge It is characterized by.
[0013]
According to a sixth aspect based on the fourth aspect, the operating state detector is configured to increase the generated current from the generated current detection means that detects the generated current of the fuel cell. Rapid increase in power It is characterized by determining.
[0014]
According to a seventh invention, in the fourth to sixth inventions, the fuel gas control device of the fuel cell compares the flow rate restriction ratio output from the opening degree selection unit with the previous flow restriction ratio, and the restriction rate change speed And an opening / closing speed adjusting section for adjusting and outputting.
[0015]
In an eighth aspect based on the seventh aspect, the opening / closing speed adjusting portion is Required power The restriction ratio changing speed is adjusted based on the above.
[0016]
【The invention's effect】
Therefore, according to the first aspect of the present invention, there is provided a fuel gas flow rate adjusting means capable of restricting the flow of the fuel gas recirculating through the recirculation passage, and the flow rate limiting ratio of the fuel gas flow rate adjusting means is input by the power generation state correcting unit. Even if the fuel cell generated power increases, the fuel supply from the fuel supply device cannot follow the required amount, and the fuel required for the reaction is insufficient at the reaction electrode of the fuel cell because the calculation control is based on the power generation state. The surplus gas can be kept in the fuel electrode of the fuel cell by the fuel gas flow rate adjusting means, and the power generation state can be prevented from being lowered due to fuel shortage.
[0017]
In addition, since only the fuel gas flow rate adjusting means capable of restricting the flow of the fuel gas flowing back through the return passage is required for the added device, the increase in the weight of the fuel cell power generation device is minimized and the cost increase is minimized. be able to.
[0018]
In the second invention, in addition to the effects of the first invention, the fuel gas flow rate adjusting means is constituted by a valve that can be set to an arbitrary opening, so that the surplus gas amount can be finely adjusted, which is suitable for the fuel cell. An excess gas amount can be provided.
[0019]
In the third invention, in addition to the effect of the first invention, the power generation state detection means is constituted by a voltmeter that detects the power generation voltage of the fuel cell, and the power generation state correction unit is based on the amount of decrease in the voltage value of the voltmeter. In order to determine the valve opening degree of the valve, the voltmeter may be a general one installed in the fuel cell device, and the power generation state can be detected without providing a new sensor for detecting the power generation state.
[0020]
In the fourth invention, in addition to the effects of the first to third inventions, when the required power detection unit detects that the required power has increased rapidly, the power rapid increase correction unit predicts a decrease in the power generation state from that point. By changing the flow rate restriction ratio of the fuel gas flow rate adjusting means, it is possible to prevent the power generation state from being lowered at the initial stage when the power suddenly increases.
[0021]
In addition, the opening degree selection unit is either the flow rate restriction rate obtained by the power generation state correction unit or the flow rate restriction rate obtained by the power sudden increase correction unit. Smaller percentage Therefore, it is possible to give an appropriate flow rate restriction ratio in a timely manner.
[0022]
In the fifth invention, in addition to the effects of the fourth invention, Above Power demand Amount of change On the basis of the Determine power surge status Thus, it is not necessary to add a new sensor or detection component by using a current voltmeter that is generally equipped with fuel cells.
[0023]
In the sixth aspect of the invention, in addition to the effect of the fourth aspect of the invention, the operating state detector is configured to increase the generated current from the generated current detection means that detects the generated current of the fuel cell. Rapid increase in power Therefore, it is not necessary to newly add a sensor or a detection component by using an ammeter generally equipped with a fuel cell.
[0024]
In the seventh invention, in addition to the effects of the fourth to sixth inventions, a sudden change in the flow rate restriction ratio is suppressed by the opening / closing speed adjusting unit, so that a sudden pressure increase or pressure drop in the fuel cell can be prevented. it can.
[0025]
In the eighth invention, in addition to the effect of the seventh invention, the opening / closing speed adjusting portion The required power Since the restriction ratio changing speed is adjusted based on the above, an appropriate opening / closing speed can be given to the pressure responsiveness that changes depending on the operating conditions. For this reason, it has the effect of preventing the rapid pressure rise and pressure drop in the fuel cell.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment for realizing a fuel gas control device for a fuel cell according to the present invention will be described based on a first embodiment corresponding to claims 1 to 3.
[0027]
(First embodiment)
1 to 4 show a fuel gas control device for a fuel cell according to a first embodiment, FIG. 1 is a system configuration diagram, FIG. 2 is a control flowchart of an arithmetic controller, and FIG. 3 is a control flowchart of a power generation correction unit in the controller. FIG. 4 shows a time chart of the power generation correction unit.
[0028]
In FIG. 1, reference numeral 1 denotes a fuel cell, and fuel gas is supplied from a fuel supply device 3 through a fuel supply passage 2. The fuel gas is converted into a generated current corresponding to the reaction fuel gas flow rate by the fuel cell 1, and the remaining surplus gas that has not reacted in the power generation reaction passes from the fuel cell 1 through the reflux passage 6 and the reflux device 4 to the fuel supply passage. 2 is supplied to the fuel cell 1 again. The recirculation passage 6 is provided with an outlet valve 5 as a fuel gas flow rate adjusting means. When the outlet valve 5 is 100% fully open, surplus gas from the outlet of the fuel cell 1 is circulated without resistance, and as the valve opening is reduced. The surplus gas exiting from the outlet of the fuel cell 1 is given a passage resistance to increase the fuel gas pressure in the fuel cell 1. The valve opening degree of the outlet valve 5 is controlled by the power generation state correction unit 8 of the arithmetic controller 14. The generated current of the fuel cell 1 is supplied to a motor / inverter 16 of a vehicle drive motor (not shown). The generated current is detected by the ammeter 15 as the generated current detection means, the generated voltage is detected by the voltmeter 7 as the generated voltage detection means, and the detection signal is input from the arithmetic controller 14 to the power generation state correction unit 8. .
[0029]
Here, the supply gas flow rate flowing through the fuel supply passage 2 is Q1, the surplus fuel gas flow rate flowing through the recirculation passage 6 is Q2, the reaction fuel gas flow rate reacted in the fuel cell 1 is Q3, and the fuel gas in the stack of the fuel cell 1 First, the operation principle of this patent will be described where the quantity is qS and the generated current is I.
[0030]
In a steady state where the amount of power generation is constant, water (H ₂ The excess fuel gas flow rate Q2 is obtained by subtracting the reaction fuel gas flow rate Q3 that becomes O). The flow balance of the fuel cell 1 at this time is expressed by the following equation (1)
Q1 = Q3 + Q2 (1)
It becomes.
[0031]
Here, in order to perform stable power generation, the supplied fuel gas flow rate Q1 has a fuel gas amount ratio SR of the following equation (2):
SR = Q1 / Q3 (2)
It is known that it is necessary to satisfy that the value is equal to or greater than a predetermined value SRA. Q3 is a fuel gas flow rate having a charge equivalent to the generated current I.
[0032]
However, when the power generation amount suddenly increases and the reaction fuel gas flow rate Q3 increases, the fuel gas amount qs in the stack temporarily decreases, and the fuel gas existing around the reaction electrode of the fuel cell 1 becomes insufficient.
[0033]
At this time, the flow rate balance around the reaction electrode of the fuel cell 1 is expressed by the following equation (3) as unit time ΔT.
Q1 × ΔT + qs = Q3 × ΔT + Q2 × ΔT (3)
It becomes. Here, the ratio SR1 of the amount of fuel gas around the reaction electrode to the reaction fuel gas Q3 per unit time ΔT is:
SR1 = (Q1 × ΔT + qs−Q2 × ΔT) / (Q3 × ΔT) (4)
It becomes. In a transient state, it can be considered that this SR1 instantaneously exceeds the predetermined value SRA, or the reduction in power generation efficiency at the time of sudden increase in power can be prevented by minimizing the amount of decrease.
[0034]
Therefore, in this patent, the outlet valve 5 is provided at the outlet of the fuel cell 1 to reduce the surplus fuel gas Q2 in the equation (4), thereby reducing the value of the ratio SR1 of the fuel gas amount around the reaction electrode in the equation (4). The aim is not to improve or improve.
[0035]
Next, the operation of the fuel gas control apparatus for a fuel cell having the above-described configuration will be described based on the periodic routine of the arithmetic controller 14 shown in FIG.
[0036]
The calculation controller 14 starts calculation in step S1, calculates the opening of the outlet valve 5 of the fuel cell 1 by the power generation state correction unit 8 in step S2, and repeats the periodic routine that ends in step S3.
[0037]
FIG. 3 shows a control flowchart in the power generation state correction unit 8 in step S2. First, in step S4, a difference DVFC [V] with respect to a preset voltage drop processing start voltage LVFC [V] of the generated voltage VFC [V] input to the arithmetic controller 14 is obtained.
[0038]
In step S5, it is determined whether or not the difference DVFC is 0 or less. If the difference DVFC is 0 or less, that is, if the difference DVFC is less than the voltage drop processing start voltage LVFC, the process proceeds to step S6. Proceed to step S9.
[0039]
In step S9, since the generated voltage VFC is equal to or higher than the voltage drop processing start voltage LVFC, the calculation controller 14 outputs the valve opening TVO2 of the outlet valve 5 in a fully open (100%) state.
[0040]
In step S6, a correction value of the opening degree of the outlet valve 5 with respect to the voltage drop is previously stored in the arithmetic controller 14 by an experiment or the like, and a voltage drop correction coefficient corresponding to the voltage drop of the difference (negative value) obtained in step S4. Find KDVFC.
[0041]
In step S7, the valve opening TVODV of the outlet valve 5 is obtained. The valve opening TVODV is obtained by subtracting a correction value consisting of the product of the differential voltage DVFC and the voltage drop correction coefficient KDVFC from the outlet valve opening when fully opened as 100%.
[0042]
In step S8, limiter processing is performed to prevent the calculation result in step S7 from becoming 0% or less. The calculation controller 14 outputs the valve opening TV02 obtained from this result as the opening of the outlet valve 5 of the fuel cell 1.
[0043]
Therefore, as shown in the time chart of FIG. 4, the load of the motor / inverter 16 increases, the generated current I increases rapidly at the time T2, the generated voltage VFC decreases from the time T2, and the voltage reduction process is performed at the time T3. Even if it falls below the start voltage LVFC, the valve opening TVO2 of the outlet valve 5 of the fuel cell 1 is reduced from the fully open state to the time T4 when the power generation voltage VFC returns from the time T3 according to the voltage drop. The temporary shortage of fuel gas in the fuel cell 1 can be compensated. The valve opening TVO2 in the figure is fully closed between time points T3 and T4. However, the valve opening degree TVO2 operates so that the valve opening degree closes only halfway according to the calculation results of steps S7 and S8.
[0044]
In the above embodiment, the power generation state detection means is obtained from the power generation voltage VFC from the voltmeter 7. Although not shown, the flow rate detection means detects the supply fuel gas flow rate Q1, and this supply fuel gas flow rate Q1. And the power generation state may be detected by the ratio of the generated current I detected by the ammeter 15.
[0045]
Further, although the surplus gas flow rate Q2 is adjusted by the outlet valve 5 provided at the outlet of the fuel cell 1 as the fuel gas flow rate adjusting means, although not shown, a fluid pump is arranged to adjust the discharge amount of the fluid pump. The surplus gas flow rate may be adjusted as follows.
[0046]
In the present embodiment, the following effects can be achieved. That is, an outlet valve 5 is provided as a fuel gas flow rate adjusting means capable of restricting the flow of the fuel gas flowing back through the reflux passage 6, and the target value of the valve opening degree of the outlet valve 5 is set by the power generation state correction unit 8 in the fuel cell 1. Since calculation control is performed based on the power generation state, the power generated by the fuel cell 1 increases, the fuel supply from the fuel supply device 3 cannot follow the required amount, and the fuel necessary for the reaction at the reaction electrode of the fuel cell 1 is not available. Even in the case of a shortage, the outlet valve 5 can keep the surplus gas in the fuel electrode of the fuel cell 1 and prevent the power generation state from being lowered due to the shortage of fuel.
[0047]
Further, the device to be added includes a fuel gas flow rate adjusting means capable of restricting the flow of the fuel gas flowing back through the reflux passage 6; do it Therefore, the increase in the weight of the fuel cell power generation device can be minimized, and the cost increase can be minimized. Further, since the fuel gas flow rate adjusting means is constituted by the outlet valve 5 which can be set to an arbitrary opening degree, the surplus gas amount can be finely adjusted, and an appropriate surplus gas amount can be given in the fuel cell 1.
[0048]
The power generation state detection means is composed of a voltmeter 7 such as a voltmeter for detecting the power generation voltage of the fuel cell 1, and the power generation state correction unit 8 calculates the valve opening of the outlet valve 5 based on the amount of decrease in the voltage value. The voltmeter 7 may be a general one installed in the fuel cell 1 and can detect the power generation state without providing a new sensor to detect the power generation state.
[0049]
(Second Embodiment)
Hereinafter, an embodiment for realizing a fuel gas control device for a fuel cell according to the present invention will be described based on a second embodiment corresponding to claims 1, 4 to 8.
[0050]
5 to 15 show a fuel gas control device for a fuel cell according to the second embodiment, FIG. 5 is a system configuration diagram, FIG. 6 is a control flowchart of an arithmetic controller, and FIGS. 7 to 12 are required power detection in the controller. Control flowcharts of a control unit, an operation state detection unit, a power sudden increase correction unit, a power generation state correction unit, an opening degree selection unit, and an opening / closing speed adjustment unit are shown. FIG. 13 shows an example of a reference table of the valve opening TVOTP with respect to the required power in the power sudden increase correction unit, and FIG. 14 shows an example of a reference table of the amount of increase / decrease in one control cycle of the valve opening in the opening / closing speed adjustment unit. FIG. 15 is a time chart showing the operating state. The same parts as those in FIG. 1 are denoted by the same reference numerals for the sake of simplicity, and the new arithmetic controller will be described in detail.
[0051]
In FIG. 5, a fuel cell 1, a fuel gas supply passage 2, a fuel gas supply device 3, a reflux device 4, an outlet valve 5, a reflux passage 6, a power generation voltage detection device 7, and a power generation state correction unit 8 are provided as in FIG. . The arithmetic controller 14 further includes a required power detection unit 9, an operation state detection unit 10, a power rapid increase correction unit 11, an opening degree selection unit 12, and an opening / closing speed adjustment unit 13.
[0052]
Control in the arithmetic controller having the above-described configuration will be described with reference to control flowcharts shown in FIGS. FIG. 6 is a control routine in the arithmetic controller 14, which periodically starts the calculation from step S9, obtains the valve opening degree of the outlet valve 5 in step S15, and repeats the routine to end one calculation in step S16.
[0053]
In step S10, the required power to the fuel cell 1 is detected, and details of the required power detection unit 9 are shown in FIG. In step S18, the required power tP obtained in another control unit or the control unit is stored in the memory. The other control unit corresponds to, for example, a drive controller that drives and controls a traveling electric motor. This required power is stored as the required power tP at time T7 in the time chart of FIG.
[0054]
The Step S11 Is a sudden increase in power demand based on changes in power demand FIG. 8 shows the details of the driving state detection unit 10. First, in step S21, it is determined whether the required power tP has changed significantly. Therefore, the difference between the previous required power tP and the current required power tP is taken, and if this difference exceeds the preset power value DP1, the process proceeds to step S22, and if it is less, the process proceeds to step S24.
[0055]
In step S22, a flag FT0 for permitting power sudden increase correction is set to 1. (In the time chart of FIG. 15, the correction permission flag is indicated by FT0.)
In step S23, a timer FT2 indicating that correction processing for power sudden increase correction is in progress is started.
[0056]
In step S24, it is determined in step S22 that the change in required power is equal to or less than a predetermined value, and the power rapid increase correction permission flag FT0 is set to zero.
[0057]
In step S25, it is determined whether or not a power sudden increase correction is currently being performed. If the timer FT2 is 0, it is not currently being corrected, and the process proceeds to S27, where the correcting flag FT1 is set to 0. If the timer FT2 is not 0, correction is currently being performed, and the process proceeds to step S26, where the correction in progress flag FT1 is set to 1.
[0058]
In FIG. 15, these flags FT0 and FT1 temporarily become FT0 = 1 at time T7, and FT1 = 1 subsequently stands from time T7 to time T9.
[0059]
Next, the process proceeds to step S12. Step S12 is to obtain the valve opening degree of the outlet valve 5 based on the change amount of the required power when the required power is suddenly increased. FIG. 9 shows details of the power sudden increase correction unit 11. The valve opening degree of the outlet valve 5 is a process in which the outlet valve 5 of the fuel cell 1 is closed immediately after the actual power generation is performed, and then the valve opening degree is gradually opened when the required power increases rapidly. The valve opening degree to be closed is increased or decreased according to the required power.
[0060]
First, in step S30, it is determined whether or not the rapid increase correction flag FT1 obtained by the driving state detection unit S11 is 1. When the rapid increase correction flag FT1 is changed from 0 to 1, the process proceeds to S31, and when the rapid increase correction flag FT1 is not changed from 0 to 0 or from 1 to 1, the process proceeds to S33.
[0061]
In step S31, the valve opening degree TVOTP when the power suddenly increases according to the required power tP is calculated and set. An example of a reference table of the valve opening TVOTP at the time of rapid increase with respect to the required power tP is shown in FIG. The valve opening table at the time of rapid increase is set to an appropriate value in advance through experiments or the like.
[0062]
In step S32, the valve opening TVOTP set in step S31 is set to TV01 as the rapid increase valve opening.
[0063]
In step S33, it is determined whether the rapid increase correction flag FT1 is 1 or not. If the rapid increase correction flag FT1 is 1, the process proceeds to step S34, and if the rapid increase correction flag FT1 is 0, the process proceeds to step S37, and the valve opening TV01 = 100% and no correction is performed.
[0064]
In step S34, a constant increase DVOOP is called from the memory of the arithmetic controller 14 from the rapid increase valve opening TVOTP set in step S31. This increment DVOOP is set in advance by experiments or the like.
[0065]
In step S35, the valve opening TVO1 is gradually opened in addition to the previous value opening TV01z by the increment DVOOP obtained in step S34.
[0066]
In step S36, a limiter is provided so as not to exceed 100%.
[0067]
In FIG. 15, the valve opening TVO1 in the power sudden increase correction unit 11 closes greatly from 100% at time T7 and gradually increases to 100% after time T8.
[0068]
Next, the process proceeds to step S13. Step S13 is similar to the power generation state correction unit 8 shown in FIG. 3, and calculates the valve opening degree of the outlet valve 5 based on the power generation state of the fuel cell 1. The contents of the power generation state correction unit 8 are shown in FIG.
[0069]
In step S40, a difference DVFC between the generated voltage VFC and the voltage reduction processing voltage LVFC is obtained. In step S41, it is determined whether the difference DVFC is 0 or less, that is, below the voltage reduction processing voltage LVFC. Proceed to S42. If the difference DVFC is 0 or more, the valve opening TV02 is set to 100% in step S45. In step S42, the voltage drop correction coefficient KDVFC is obtained. In step S43, the valve opening degree TVO2 is obtained. In step S44, limiter processing for preventing the calculation result of the valve opening degree from being 0% or less is performed.
[0070]
In FIG. 15, the valve opening TVO2 is controlled so as to temporarily decrease the valve opening from time T8 to T9.
[0071]
Next, the process proceeds to step S14. In step S14, the valve opening TVO1 determined by the power sudden increase correction unit 11 in step S12 and the valve opening TVO2 determined in the power generation state correction unit 8 in step S13. And the opening on the smaller side The opening selection section 12 to be selected is shown in FIG.
[0072]
In step S48, if the correction-permitted flag FT1 is 1, the requested power rapid increase process or the power generation state is being corrected, and the process proceeds to step S49. If the correction-permitted flag FT1 is 0, the above processing is not in progress, and thus the process proceeds to step S50 and the valve opening TV03 is set to 100%.
[0073]
In step S49, the smaller one of the valve opening TV01 obtained by the power rapid increase correction unit 11 and the valve opening TV02 obtained by the power generation state correction unit 8 is set as the valve opening TV03.
[0074]
In FIG. 15, the valve opening TVO3 is suddenly decreased from time T7, is decreased from time T8 to 0 opening, and is changed to return to 100% again at time T9.
[0075]
Next, the process proceeds to step S15. Step S15 is the opening / closing speed adjusting unit 13 for setting the valve opening / closing speed of the outlet valve 5, and the contents thereof are shown in FIG. Here, the opening / closing speed adjusting unit 13 adjusts the speed in the direction of increasing the opening and decreasing the opening.
[0076]
In step S53, it is determined whether the valve opening degree is increasing or decreasing depending on the target value TVO3 of the valve opening degree with respect to the previous value TVO4z. If it has increased, the process proceeds to step S54, and if it has decreased, the process proceeds to step S58.
[0077]
In step S54, the valve opening increase amount DTVOE corresponding to the required power tP is obtained from the reference table TDTVOE. In the reference table TDTVOE, as shown in FIG. 14, an increase amount DTVOE with respect to the required power tP is obtained and set in advance through experiments or the like.
[0078]
Next, the process proceeds to step S55, where the increase amount DTVOE obtained in step S54 is added to the previous value TVO4z to obtain the current valve opening TVOG.
[0079]
In step S56, the valve opening TV03 obtained by the valve opening selector 12 is compared with the current valve opening TVOG, and the smaller one is set as TV04. Of course, when these valve openings exceed 100%, the valve opening TV04 is set to 100%.
[0080]
In step S58, the valve opening according to the required power tP. Decrease The quantity DTVOF is determined from the table TDTVOF. TDTVOF sets in advance the table shown in FIG.
[0081]
Next, the process proceeds to step S59, where the target valve opening TVOG is obtained by subtracting the decrease amount DTVOF from the previous value TVO4z.
[0082]
In step S60, the larger one of the target valve opening TVOG and the valve opening TV03 obtained by the opening selection unit 12 is set as the current valve opening TV04.
[0083]
In step S57, the outlet valve opening TV04 obtained by the above calculation is output from the calculation controller 14 to the outlet valve 5 of the fuel cell 1.
[0084]
In FIG. 15, the valve opening TVO4 is gentle with a time delay with respect to the opening TVO3.
[0085]
In the above description, the opening / closing speed is set by the opening / closing speed adjusting unit 13 so that the opening speed is different from the closing speed, but may be set at the same speed. Further, the opening / closing speed adjusting unit 13 is not necessarily required.
[0086]
Said The driving state detection unit 10 uses the required power tP. Rapid increase in required power However, the present invention is not limited to this, and as shown in FIG. 16, the generated current is based on the generated current I from the ammeter 15, and the above-mentioned Rapid increase in power May be detected.
[0087]
In the present embodiment, in addition to the effects in the first embodiment, the following effects can be achieved. That is, when the required power detection unit 9 detects that the required power tP has increased rapidly, the power rapid increase correction unit 11 predicts a decrease in the power generation state from that point and the flow rate restriction ratio of the outlet valve 5 as the fuel gas flow rate adjusting means By changing, it is possible to prevent a decrease in the power generation state at the initial stage when the power suddenly increases.
[0088]
Further, the opening degree selection unit 12 is either the flow rate restriction rate obtained by the power generation state correction unit 8 or the flow rate restriction rate obtained by the power rapid increase correction unit 11. Smaller percentage Therefore, it is possible to give an appropriate flow rate restriction ratio in a timely manner.
[0089]
Means for detecting power sudden increase state As required power tP change of By using the current voltmeter generally provided in the fuel cell 1, it is not necessary to add a new sensor or detection component.
[0090]
Since the opening / closing speed adjusting unit 13 suppresses a sudden change in the flow rate restriction ratio, a sudden pressure increase or pressure decrease in the fuel cell 1 can be prevented.
[0091]
By the opening / closing speed adjustment unit 13 The required power Since the restriction ratio changing speed is adjusted based on the above, an appropriate opening / closing speed can be given to the pressure responsiveness that changes depending on the operating conditions. For this reason, it has the effect which prevents the rapid pressure rise and pressure fall in the fuel cell 1 further.
[0092]
The operating state detection unit 10 is configured according to the amount of increase in the generated current from the ammeter 15 that detects the generated current I of the fuel cell 1. Rapid increase in power Therefore, it is not necessary to newly add a sensor or a detection component by using an ammeter generally provided in the fuel cell 1.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a fuel gas control device for a fuel cell according to an embodiment of the present invention.
FIG. 2 is a control flowchart of the arithmetic controller.
FIG. 3 is a control flowchart of a power generation correction unit in the arithmetic controller.
FIG. 4 is a time chart showing the operation of the fuel gas control device.
FIG. 5 is a system configuration diagram of a fuel gas control device for a fuel cell according to a second embodiment of the present invention.
FIG. 6 is a control flowchart of the arithmetic controller.
FIG. 7 is a flowchart showing a subroutine of a required power detection unit in the arithmetic controller.
FIG. 8 is a flowchart showing a subroutine of an operation state detection unit in the arithmetic controller.
FIG. 9 is a flowchart showing a subroutine of a correction unit for sudden increase in power in the arithmetic controller.
FIG. 10 is a flowchart showing a subroutine of a power generation state correction unit in the arithmetic controller.
FIG. 11 is a flowchart showing a subroutine of an opening degree selection unit in the arithmetic controller.
FIG. 12 is a flowchart showing a subroutine of an opening / closing speed adjustment unit in the arithmetic controller.
FIG. 13 is a graph showing an example of a reference table of valve opening TVOTP with respect to required power in a power sudden increase correction unit.
FIG. 14 is a graph showing an example of a reference table for an increase / decrease amount in one control cycle of the valve opening degree in the opening / closing speed adjustment unit.
FIG. 15 is a time chart showing the operation of the fuel gas control device.
FIG. 16 is a system configuration diagram showing a modification of the operation state detection of the fuel cell.
[Explanation of symbols]
1 Fuel cell
2 Fuel supply passage
3 Fuel supply device
4 reflux equipment
5 Outlet valve as fuel gas flow rate adjusting means
6 Return passage
7 Voltmeter (Generation voltage detection means)
8 Power generation state correction unit (Power generation state correction means)
9 Required power detector
10 Operating state detector
11 Power sudden increase correction unit
12 Opening selector
13 Opening and closing speed adjustment part
14 Arithmetic controller
15 Ammeter (Generation current detection means)
16 Motor inverter

Claims (8)

A fuel cell that generates electric power by receiving fuel gas and oxidant gas supplied to the fuel electrode and oxidant electrode, a fuel supply passage that supplies fuel gas to the fuel cell, and surplus gas from the fuel cell; In a fuel cell comprising a return passage that returns to the fuel supply passage,
Fuel gas flow rate adjusting means capable of restricting the flow of the fuel gas flowing back through the reflux passage;
Power generation state detection means for detecting the power generation state of the fuel cell;
A fuel generation state correction unit that calculates a flow rate restriction ratio of the fuel gas flow rate adjusting unit based on a power generation state input from the power generation state detection unit and outputs the calculated rate to the fuel gas flow rate adjustment unit. Battery fuel gas control device.   2. The fuel gas control device for a fuel cell according to claim 1, wherein the fuel gas flow rate adjusting means is a valve that can be set to an arbitrary opening degree.   The power generation state detection means is a voltmeter that detects a power generation voltage of a fuel cell, and the power generation state correction unit calculates a valve opening based on a decrease amount of a voltage value of the voltmeter. Item 2. A fuel gas control device for a fuel cell according to Item 1. The fuel gas control device for the fuel cell comprises:
A required power detector for detecting required power to the fuel cell;
An operating state detector that detects a sudden increase in required power ;
A power rapid increase correction unit for obtaining a flow rate limiting ratio of the fuel gas flow rate control means based on a change amount of the required power that rapidly increases when the required power rapidly increases;
In that it comprises a opening selector which forces out by selecting the ratio of one small side of the flow restriction rate obtained by the flow restriction ratio or power surge correction unit obtained by the power generation state correction unit The fuel gas control device for a fuel cell according to any one of claims 1 to 3, wherein the fuel gas control device is a fuel gas control device. The driving state detection unit, the fuel cell of the fuel gas control device according to claim 4, characterized in that determine the constant power surge condition based on a change in the required power. 5. The fuel gas control of a fuel cell according to claim 4, wherein the operating state detection unit determines the power sudden increase state based on an increase amount of the generated current from the generated current detection means for detecting the generated current of the fuel cell. apparatus.   The fuel gas control device of the fuel cell includes an opening / closing speed adjustment unit that adjusts and outputs a restriction rate change rate by comparing a flow rate restriction rate output from the opening degree selection unit with a previous flow rate restriction rate. The fuel gas control device for a fuel cell according to any one of claims 4 to 6, wherein the fuel gas control device is for a fuel cell. 8. The fuel gas control apparatus for a fuel cell according to claim 7, wherein the opening / closing speed adjusting unit adjusts a limit ratio changing speed based on the required power .

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