JP2009299480A - Pump drive control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump drive control device performing operation having high system efficiency in response to the actual pump performance. <P>SOLUTION: The actual pump workload (power consumption) when constantly controlling the actual pump rotational speed is detected, and volumetric efficiency of a pump is calculated based on the detected actual pump power consumption and rotational speed. The calculated volumetric efficiency ηv is plotted on an operation management map M and a reference line l1 of the volumetric efficiency ηv is corrected, thereby acquiring the actual line l11. The actual pump operation is controlled using the acquired actual line l11. Thereby, it is possible to control the operation having the high system efficiency in comparison with the past example that a lower limit line l01 acquired when using the worst pump is always used, without taking into consideration the actual pump performance due to product variation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pump drive control device applied to a fuel cell system.

  A fuel cell is a power generation system that directly converts energy released in an oxidation reaction into electric energy by oxidizing a fuel gas containing hydrogen by an electrochemical process, and an electrolyte for selectively transporting hydrogen ions. A stack structure is formed by laminating a plurality of membrane-electrode assemblies in which both sides of the membrane are sandwiched between a pair of electrodes made of a porous material. Among them, a solid polymer electrolyte fuel cell using a solid polymer membrane as an electrolyte is expected to be used as an in-vehicle power source because it is low-cost and easy to downsize and has a high output density. (For example, refer to Patent Document 1).

FIG. 4 is a diagram showing a schematic configuration of a fuel gas supply system of the fuel cell system.
The fuel gas supply system 100 includes an injector 400 for supplying a fuel gas containing hydrogen to the fuel cell 200, a fuel gas passage 110 through which the fuel gas supplied to the anode electrode of the fuel cell 200 flows, and an exhaust from the fuel cell 20. A circulation passage 120 for returning the fuel off-gas to the fuel gas passage 110, a hydrogen circulation pump 300 for pressure-feeding the fuel off-gas in the circulation passage 120 to the fuel gas passage 43, and an exhaust passage branchingly connected to the circulation passage 47 130 and a purge valve 500 for adjusting the exhaust amount of the fuel off-gas.

  A feature of the hydrogen circulation pump 300 of the prior art is that the tolerance of the leak amount allowed at the time of manufacture is large. This is because the molecular weight of hydrogen contained in the fuel gas is small, and the amount of hydrogen gas leaking from the gap of the pump is larger than the amount of other gases leaking from the gap of the pump. For this reason, conventionally, there has been a problem that variation in the amount of leakage between pumps cannot be suppressed.

  On the other hand, if the fuel gas (that is, hydrogen) supplied to the fuel cell 200 is insufficient, the catalyst deteriorates. Therefore, no matter what kind of hydrogen circulation pump 300 is applied (in other words, the amount of leakage varies greatly). No matter which hydrogen circulation pump 300 is applied), it is necessary to supply more fuel gas so that the minimum necessary hydrogen is supplied to the fuel cell.

FIG. 5 is a diagram exemplifying a drive map used when a hydrogen circulation pump is used. The vertical axis indicates the work amount, and the horizontal axis indicates the rotation speed.
Conventionally, in order to secure the minimum required hydrogen, the relationship between the number of rotations and the amount of work that can be obtained when using a hydrogen circulation pump (hereinafter referred to as the lowest pump) with the lowest performance (largest leakage) is shown. The hydrogen circulation pump was operated using the lower limit line (indicated by a solid line in FIG. 5).
JP 2003-81603 A

  However, since the performance of the hydrogen circulation pump actually used in the system is higher than that of the lowest pump, the rotation speed and work load obtained when using the actually used hydrogen circulation pump (hereinafter, actual pump) are reduced. The actual line representing the relationship (indicated by a dotted line in FIG. 5) has a larger slope than the lower limit line.

  Therefore, if the actual pump is operated using the lower limit line obtained when the lowest pump is used, it is necessary to do extra work (see ΔW1 to ΔW3 shown in FIG. 5), and the system efficiency is reduced. There was a problem.

  The present invention has been made in view of the circumstances described above, and an object of the present invention is to provide a pump drive control device capable of operating with high system efficiency in accordance with the performance of an actual pump.

  In order to solve the above-described problems, a pump drive control device according to the present invention associates a relationship between a pump for sending fuel gas containing hydrogen to a gas supply path of a fuel cell system and the rotational speed of the pump and power consumption. Storage means for storing pump control information, calculation means for calculating the volumetric efficiency of the pump based on the detected rotation speed and power consumption of the pump, and correction of the pump control information based on the calculated volumetric efficiency And a drive control means for controlling the drive of the pump using the pump control information.

  According to this configuration, the volumetric efficiency of the pump is calculated based on the detected power consumption and rotation speed of the actual pump, and the operation of the actual pump is controlled based on the calculated volumetric efficiency. As a result, since the operation is controlled in a state that reflects the performance of the actual pump, the actual pump can be operated using the data obtained when the lowest pump is used without considering the performance of the actual pump due to manufacturing variations. Compared with the conventional example that has been operated, it is possible to perform operation control with higher system efficiency, and it is possible to further suppress the flow rate error of the actual pump.

  In the above configuration, the calculation means obtains the power consumption of the pump when the rotation speed of the pump is controlled to be constant, and calculates the volume efficiency based on the obtained power consumption of the pump and the rotation speed of the pump. The aspect to calculate is preferable.

  Moreover, in the said structure, the said pump is a circulation pump which returns a part of fuel off gas output from a fuel cell to the said gas supply path, and the aspect in which a water | moisture content is contained in the said fuel off gas is still more preferable.

  In the above configuration, it is preferable that the calculation unit calculates the volumetric efficiency at the initial start of the pump.

  In the above configuration, it is preferable that the calculation unit calculates the volume efficiency after stopping the power generation of the fuel cell.

  Further, in the above configuration, the fuel cell further includes a detecting unit that detects a degree of drying of the electrolyte membrane of the fuel cell, and the calculating unit is configured to reduce the volume when the degree of drying of the electrolyte membrane becomes a set value or more. A mode of calculating efficiency is also preferable.

  In the above configuration, it is preferable that the calculation unit calculates the volume efficiency after scavenging the fuel gas circulation system after stopping the power generation of the fuel cell.

  Further, in the above configuration, the calculation means obtains the power consumption of the pump when the rotation speed of the pump is controlled to be constant in the vicinity of the set maximum rotation speed, and the calculated power consumption of the pump A mode in which the volumetric efficiency is calculated based on the number of rotations of the pump is also preferable.

  Further, in the above configuration, the inverter further includes an inverter connected to the pump, and current / voltage detection means for detecting an output current and an output voltage of the inverter, and the calculation means includes the detected inverter. A mode in which the power consumption of the pump is obtained based on the output current and the output voltage is preferable.

In the above configuration, the first pressure detecting means for detecting the inflow pressure of the fuel gas flowing into the pump, and the second pressure detecting means for detecting the outflow pressure of the fuel gas flowing out of the pump Further comprising
The calculation means obtains the power consumption of the pump when the rotation speed of the pump is controlled to be constant, the obtained power consumption of the pump, the rotation speed of the pump, the detected inflow pressure, and the detected outflow pressure. Based on the above, it is preferable to calculate the volume efficiency.

  Further, in the above configuration, the calculation means detects the rotation speed of the pump when the pump is driven with a set power, and based on the detected rotation speed of the pump and the power consumption of the pump, The aspect which calculates the said volume efficiency is preferable.

  According to the present invention, it is possible to operate with high system efficiency according to the performance of the actual pump.

A. Embodiments Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
FIG. 1 shows a system configuration of a fuel cell system 10 mounted on a vehicle according to the present embodiment.
The fuel cell system 10 according to the present embodiment calculates the volumetric efficiency of the actual pump at a predetermined timing in order to enable operation with high system efficiency according to the performance of the actual pump, and the actual efficiency based on the calculated volumetric efficiency. It is characterized by controlling the operation of the pump. Here, the volumetric efficiency of the actual pump refers to the ratio of the gas flow rate actually flowing out from the actual pump on the basis of the gas flow rate when it is assumed that there is no leakage in the actual pump (details will be described later).

  In the following description, a fuel cell vehicle (FCHV) is assumed as an example of the vehicle, but the present invention can also be applied to an electric vehicle and a hybrid vehicle. Further, the present invention can be applied not only to vehicles but also to various moving bodies (for example, ships, airplanes, robots, etc.), stationary power sources, and portable fuel cell systems.

  The fuel cell system 10 functions as an on-vehicle power supply system mounted on a fuel cell vehicle. The fuel cell system 10 generates power by receiving supply of a reaction gas (fuel gas, oxidant gas), and air as oxidant gas. An oxidizing gas supply system 30 for supplying the fuel cell 20, a fuel gas supply system 40 for supplying hydrogen gas as a fuel gas to the fuel cell 20, and a power system 50 for controlling charging / discharging of power A cooling system 60 for cooling the fuel cell 20 and a controller 70 for controlling the entire system are provided.

  The fuel cell 20 is a solid polymer electrolyte cell stack formed by stacking a plurality of cells in series. In the fuel cell 20, the oxidation reaction of the formula (1) occurs at the anode electrode, and the reduction reaction of the equation (2) occurs at the cathode electrode. In the fuel cell 20 as a whole, an electromotive reaction of the formula (3) occurs.

_{^{H 2 → 2H + + 2e -}} ... (1)
(1/2) O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (2)
H ₂ + (1/2) O ₂ → H ₂ O (3)

  The fuel cell 20 is provided with a voltage sensor 71 for detecting the output voltage of the fuel cell 20 and a current sensor 72 for detecting the generated current.

  The oxidizing gas supply system 30 has an oxidizing gas passage 34 through which oxidizing gas supplied to the cathode electrode of the fuel cell 20 flows and an oxidizing off gas passage 36 through which oxidizing off gas discharged from the fuel cell 20 flows. In the oxidizing gas passage 34, an air compressor 32 that takes in the oxidizing gas from the atmosphere via the filter 31, a humidifier 33 for humidifying the oxidizing gas supplied to the cathode electrode of the fuel cell 20, and an oxidizing gas supply amount And a throttle valve 35 for adjusting. The oxidizing off gas passage 36 includes a back pressure adjusting valve 37 for adjusting the oxidizing gas supply pressure, and a humidifier 33 for exchanging moisture between the oxidizing gas (dry gas) and the oxidizing off gas (wet gas). Is provided.

  Between the oxidizing gas passage 34 and the oxidizing off gas passage 36, a bypass passage 38 that bypasses the fuel cell 20 and connects the two, and a bypass valve 39 that adjusts the flow rate of the oxidizing gas flowing through the bypass passage 38 are disposed. Has been. The bypass valve 39 is normally closed and is opened during a voltage drop process described later. The bypass passage 38 and the bypass valve 39 function as bypass means for adjusting the bypass air flow rate.

  The fuel gas supply system 40 includes a fuel gas supply source 41, a fuel gas passage 45 through which the fuel gas supplied from the fuel gas supply source 41 to the anode electrode of the fuel cell 20 flows, and a fuel off-gas discharged from the fuel cell 20. A circulation passage 46 for returning to the fuel gas passage 45, a circulation pump (pump) 47 for pumping the fuel off-gas in the circulation passage 46 to the fuel gas passage (gas supply passage) 45, and a branch connection to the circulation passage 46. And an exhaust drainage passage 48.

  The fuel gas supply source 41 is made of, for example, a high-pressure hydrogen tank or a hydrogen storage alloy, and stores high-pressure (for example, 35 MPa to 70 MPa) hydrogen gas. When the shut-off valve 42 is opened, the fuel gas flows out from the fuel gas supply source 41 into the fuel gas passage 45. The fuel gas is decompressed to, for example, about 200 kPa by the regulator 43 and the injector 44 and supplied to the fuel cell 20.

  The fuel gas supply source 41 includes a reformer that generates a hydrogen-rich reformed gas from a hydrocarbon-based fuel, and a high-pressure gas tank that stores the reformed gas generated by the reformer in a high-pressure state. It may be configured.

  The regulator 43 is a device that regulates the upstream side pressure (primary pressure) to a preset secondary pressure, and includes, for example, a mechanical pressure reducing valve that reduces the primary pressure. The mechanical pressure reducing valve has a housing in which a back pressure chamber and a pressure adjusting chamber are formed with a diaphragm therebetween, and the primary pressure is reduced to a predetermined pressure in the pressure adjusting chamber by the back pressure in the back pressure chamber. It has a configuration for the next pressure.

  The injector 44 is an electromagnetically driven on-off valve capable of adjusting the gas flow rate and gas pressure by driving the valve body directly with a predetermined driving cycle with an electromagnetic driving force and separating the valve body from the valve seat. The injector 44 includes a valve seat having an injection hole for injecting gaseous fuel such as fuel gas, a nozzle body for supplying and guiding the gaseous fuel to the injection hole, and an axial direction (gas flow direction) with respect to the nozzle body. And a valve body that is slidably accommodated and opens and closes the injection hole.

  An exhaust / drain valve 49 is disposed in an exhaust / drain passage 48 branched and connected to the circulation passage 46. The exhaust / drain valve 49 is operated according to a command from the controller 70 to discharge the fuel off-gas and impurities including impurities in the circulation passage 46 to the outside. By opening the exhaust drain valve 49, the concentration of impurities in the fuel off-gas in the circulation passage 46 is lowered, and the hydrogen concentration in the fuel off-gas circulating in the circulation system can be increased.

  The fuel off gas discharged through the exhaust drain valve 49 is mixed with the oxidizing off gas flowing through the oxidizing off gas passage 34 and diluted by a diluter (not shown). The circulation passage 46 has a circulation pump 46 that pumps the fuel off-gas in the circulation passage 46 to the fuel gas passage 45. Adjustment of the amount of fuel off-gas returned to the supply passage 22 is realized by controlling the rotational speed of the circulation pump 46 based on a control command from the controller. Further, in the circulation passage 46, a pressure sensor P1 that detects the pressure (upstream pressure) of the fuel off-gas flowing into the circulation pump 46, and a pressure that detects the pressure (downstream pressure) of the fuel off-gas that flows out of the circulation pump 46. A sensor P2 is provided.

  The power system 50 includes a DC / DC converter 51, a battery 52, a traction inverter 53, a traction motor 54, and auxiliary machinery 55. The DC / DC converter 51 boosts the DC voltage supplied from the battery 52 and outputs it to the traction inverter 53, and the DC power generated by the fuel cell 20 or the regenerative power recovered by the traction motor 54 by regenerative braking. And a function of charging the battery 52 by lowering the voltage. The charge / discharge of the battery 52 is controlled by these functions of the DC / DC converter 51. Further, the operation point (output voltage, output current) of the fuel cell 20 is controlled by voltage conversion control by the DC / DC converter 51.

  The battery 52 functions as a surplus power storage source, a regenerative energy storage source during regenerative braking, and an energy buffer during load fluctuations associated with acceleration or deceleration of the fuel cell vehicle. As the battery 52, for example, a secondary battery such as a nickel / cadmium storage battery, a nickel / hydrogen storage battery, or a lithium secondary battery is suitable.

  The traction inverter 53 is, for example, a PWM inverter driven by a pulse width modulation method, and converts a DC voltage output from the fuel cell 20 or the battery 52 into a three-phase AC voltage according to a control command from the controller 70, The rotational torque of the traction motor 54 is controlled. The traction motor 54 is a three-phase AC motor, for example, and constitutes a power source of the fuel cell vehicle.

  Auxiliary machines 55 are motors (for example, power sources such as pumps) arranged in each part in the fuel cell system 10, inverters for driving these motors, and various on-vehicle auxiliary machines. (For example, an air compressor, an injector, a cooling water circulation pump, a radiator, etc.) is a general term.

  The controller 70 is configured as a microcomputer having a CPU, ROM, and RAM therein. The CPU executes a desired calculation according to the control program and performs various processes and controls such as control of normal operation. The ROM stores control programs and control data processed by the CPU. The RAM is mainly used as various work areas for control processing.

  The controller 70 is based on the pressure sensors Ps and Pd, the temperature sensor, the start signal IG output from the ignition switch, the accelerator opening signal ACC output from the accelerator sensor, the vehicle speed signal VC output from the vehicle speed sensor, and the like. A control signal is output to each component (compressor 32, hydrogen circulation pump 47, etc.).

Hereinafter, the point that the volume efficiency of the actual pump (actual hydrogen circulation pump 47) is calculated at a predetermined timing, which is a feature of the present embodiment, and the operation of the actual pump is controlled based on the calculated volume efficiency will be described in detail.
As explained in the section of the prior art, the characteristic of the hydrogen circulation pump 47 of the prior art is that the tolerance of the leak amount allowed at the time of manufacture is large. This is because the molecular weight of hydrogen contained in the fuel gas is small, and the amount of hydrogen gas leaking from the gap of the pump is larger than the amount of other gases leaking from the gap of the pump. For this reason, conventionally, there has been a problem that variation in the amount of leakage between pumps cannot be suppressed. In addition, the fuel off-gas pumped by the hydrogen circulation pump 47 includes moisture (water generated at the time of power generation of the fuel cell), but the current technology does not evaporate the moisture (that is, without heating). ), It is difficult to accurately measure the flow rate of gas containing moisture.

  In view of such circumstances, in the present embodiment, the work amount (power consumption) of the actual pump when the rotation speed of the actual pump is controlled to be constant is detected, and the pump power is determined based on the detected power consumption and rotation speed of the actual pump. The volume efficiency is calculated, and the operation of the actual pump is controlled based on the calculated volume efficiency.

2 and 3 are diagrams illustrating an actual pump operation management map (pump control information) M1 stored in the memory (storage means) 60. FIG.
As shown in FIG. 2, the operation management map M1 includes rotational speeds at each volume efficiency ηv = 0.5 (50%), ηv = 0.6 (60%), and ηv = 0.7 (70%). Lines l01 to l03 representing the relationship between and the work amount are shown. Among these, the line l01 representing the relationship between the rotational speed and the work amount when the volumetric efficiency ηv = 0.5 (50%) is a reference line.

  For convenience, FIG. 2 shows a case where three types of ηv are shown, but a line representing the relationship between the rotational speed and the work amount when the volumetric efficiency ηv = 1 (100%) is also registered. Of course, a line representing the relationship between the rotational speed and the work amount at other volumetric efficiency ηv may be registered. In addition, the relationship between the rotation speed and the work amount at each volume efficiency ηv registered in advance in the operation management map M1 can be obtained by, for example, experiments. The pump used in the experiment may be the actual pump 47 mounted on the vehicle, but may be another pump allowed within the tolerance range.

<When volume efficiency of actual pump is calculated immediately after production>
In the present embodiment, first, after the fuel cell system 10 is assembled, the volumetric efficiency is obtained when the hydrogen circulation pump 47 is driven for the first time. Thus, the reason why the volume efficiency is obtained when the actual pump 47 is driven for the first time is that the volume efficiency of the actual pump is highly dependent on individual differences and is less dependent on durability deterioration.

  After the assembly of the fuel cell system 10 is completed, the controller (calculating means) 70 sends an instruction to rotate at a constant rotational speed to the actual pump 47. As for the rotation speed to be set, the rotation speed N near the maximum rotation speed (the rotation speed N1 shown in FIG. 2) is desirable. The reason for this is that, as shown in FIG. 2, the higher the number of revolutions, the more stable the pressure loss, the greater the difference in volume efficiency, and the more efficient volume efficiency is required.

When the rotation speed is set to be constant, the controller 70 reads the work amount (hereinafter, the theoretical work amount) Q when assuming that the volume efficiency ηv = 1 (100%) at this rotation speed from the memory 60. The theoretical work Q is proportional to the rotational speed N (rpm) as shown in the following formula (1). It should be noted that the theoretical work Q is derived in advance by calculation or the like and registered in the memory 60.
Q Ｎ N (1)

Further, the controller (calculating means) 70 receives the pressure (inflow pressure) Ps of the fuel off-gas flowing into the actual pump 47 from the pressure sensor (first pressure detecting means) P1, and at the same time the pressure sensor (second pressure detecting means). The pressure (outflow pressure) Pd of the fuel off gas flowing out from the actual pump 47 is received from P2. In addition, the controller (the calculation main sun) 70 obtains the mechanical loss (so-called mechanical loss) Wm of the actual pump 47 stored in the memory 60, and serves as an inverter of the motor 46a that drives the actual pump 47. The work amount W (= i * v; work amount W1 shown in FIG. 3) is obtained from the current value i and voltage value v indicated by the connected ammeter and voltmeter (current / voltage detection means). Since the fluctuation of the mechanical loss Wm is relatively small, it may be stored in the memory 60 as a fixed value. The controller 70 calculates the volume efficiency ηv of the actual pump 47 at that time by substituting these values into the following formula (2).
W = (Pb−Ps) * Q / ηv + Wm (2)

  Thereafter, the controller (correction means) 70 refers to the operation management map M1 of the actual pump 47 registered in the memory 60, and sets the rotation speed N (here, the rotation speed N1) and the obtained work amount W (here) Then, the work amount W1) is plotted on the operation management map M1, and the actual line l11 shown in FIG. 3 is obtained by correcting the reference line l1 of the volume efficiency ηv.

  The controller (drive control means) 70 controls the operation of the actual pump (hydrogen circulation pump) 47 using the obtained actual line l11. Since the actual line l11 obtained reflects the performance of the actual pump 47, the lower limit line (for example, the figure) obtained when the lowest pump is used without considering the performance of the actual pump 47 due to manufacturing variation or the like. Compared with the conventional example in which the reference line 1011) shown in FIG. 3 is always used, it is possible to control the operation with higher system efficiency and to suppress the flow rate error of the actual pump 47.

B. Modification <Modification 1>
In the present embodiment described above, the case where the volumetric efficiency ηv of the actual pump 47 is obtained immediately after manufacture has been described, but the timing for obtaining the volumetric efficiency ηv can be set and changed as appropriate according to the system or the like. Specifically, the controller (calculating means) performs (1) immediately after stopping the power generation of the fuel cell, (2) performed when the degree of drying of the electrolyte membrane of the fuel cell is a predetermined value or more, (3) the fuel cell It may be performed immediately before the start of power generation or immediately after the scavenging process after power generation is stopped (immediately after the pressurization process). According to (1), since the concentration of the hydrogen circulation system is stable immediately after power generation is stopped (that is, immediately after shutdown), the pressure loss (pressure difference between the inlet and outlet of the pump) is also stabilized and measured with high accuracy. It becomes possible. Further, according to (2), the remaining water amount of the fuel cell 20 can be easily managed, the pressure loss is stable, and the measurement can be performed with high accuracy. As a method for measuring the degree of drying of the electrolyte membrane of the fuel cell, the controller (detecting means, calculating means) 70 measures the impedance of the fuel cell 20 by a known AC impedance method, and the electrolyte membrane is dried based on the measurement result. Find the degree. Further, according to (3), since the concentration of the hydrogen circulation system is stable, the pressure loss is also stable and measurement can be performed with high accuracy. Of course, the purpose is not limited to these timings, and the volumetric efficiency ηv may be obtained at regular intervals (for example, every month).

<Modification 2>
In the present embodiment described above, the pressure sensor P1 that detects the pressure (upstream pressure) Ps of the fuel off-gas flowing into the actual pump 47, and the pressure that detects the pressure (downstream pressure) Pd of the fuel off-gas that flows out of the actual pump 47. Although the case where the sensor P2 is provided has been described, the present invention is also applicable when only one of the pressure sensors (for example, the pressure sensor P2 that detects the downstream pressure Pd) is provided. In this case, an estimated value may be used for a pressure that is not actually measured (for example, upstream pressure). Thus, the reason why the estimated value can be used for the pressure is that the variation in pressure loss is not large as an individual difference, so that even if the estimated value is used, the error is small. Note that estimated values may be used for both the upstream pressure Ps and the downstream pressure Pd.

<Modification 3>
In the present embodiment described above, the mechanical loss Wm is always constant, but the volumetric efficiency ηv may be calculated in consideration of the varying mechanical loss. In general, as the total operating time (lifetime rotational speed) of an actual pump increases, mechanical loss tends to gradually decrease due to wear of members near the seal. Therefore, the relationship between the lifetime rotation speed and the mechanical loss of the hydrogen circulation pump is obtained in advance by experiments or the like, and this is registered in the memory 60 as the mechanical loss management map M2. When determining the volumetric efficiency ηv, the controller 70 detects the rotational speed N at that time, and then refers to the mechanical loss management map M2 registered in the memory 60 to determine the mechanical loss Wm corresponding to the rotational speed N. get. And the controller 70 calculates | requires volumetric efficiency (eta) v by substituting the acquired mechanical loss Wm to the said Formula (2). With this configuration, it is possible to calculate the volume efficiency ηv with higher accuracy.

<Modification 4>
In the present embodiment and the modification described above, the rotational speed is controlled to be constant, and the volume efficiency ηv is obtained based on the work amount (power consumption) W obtained in this case and the rotational speed N, but not the rotational speed. The work efficiency (power consumption) may be determined in advance (in other words, with the set power), and the volume efficiency ηv may be obtained based on the rotation speed N and the work W obtained in this case.

When obtaining the volumetric efficiency ηv, the hydrogen circulation pump 46 is driven using the power supplied from the battery 52 or the like. However, in the method of controlling the rotational speed to be constant, the battery 52 has sufficient power. Since it does not remain, there is a concern that the control cannot be performed and the volumetric efficiency ηv cannot be obtained.
Therefore, the power consumption (work amount) of the hydrogen circulation pump 47 is determined in advance, the controller (calculation means) 70 calculates the rotation speed N with the determined power consumption, and based on the calculated rotation speed N and power consumption, The volumetric efficiency may be calculated. Further, the controller 70 may calculate the volume efficiency ηv using the torque value of the hydrogen circulation pump 47.

1 is a system configuration diagram of a fuel cell system according to an embodiment. FIG. It is the figure which illustrated the operation management map of the real pump stored in memory. It is the figure which illustrated the operation management map of the real pump stored in memory. It is a figure which shows schematic structure of the fuel gas supply system of a fuel cell system. It is the figure which illustrated the drive map utilized when utilizing a hydrogen circulation pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system, 20 ... Fuel cell, 30 ... Oxidation gas supply system, 40 ... Fuel gas supply system, 47 ... Hydrogen circulation pump, 50 ... Electric power system, 60. ..Memory, 70... Controller, P1, P2.

Claims (11)

A pump for sending fuel gas containing hydrogen to the gas supply path of the fuel cell system;
Storage means for storing pump control information associating the relationship between the rotational speed of the pump and power consumption;
Calculation means for calculating the volumetric efficiency of the pump based on the detected rotational speed and power consumption of the pump;
Correction means for correcting the pump control information based on the calculated volumetric efficiency;
A pump drive control device comprising: drive control means for controlling drive of the pump using the pump control information.   The said calculating means calculates | requires the power consumption of this pump at the time of controlling the rotation speed of a pump uniformly, and calculates the said volume efficiency based on the calculated | required power consumption of a pump and the rotation speed of a pump. The pump drive control device described.   The pump drive control device according to claim 2, wherein the pump is a circulation pump that returns a part of the fuel off-gas output from the fuel cell to the gas supply path, and the fuel off-gas contains moisture.   The pump drive control device according to claim 2, wherein the calculation unit calculates the volumetric efficiency when the pump is first started.   The pump drive control device according to claim 2, wherein the calculation unit calculates the volumetric efficiency after stopping the power generation of the fuel cell. Further comprising a detecting means for detecting the degree of drying of the electrolyte membrane of the fuel cell,
The pump drive control device according to claim 2, wherein the calculation means calculates the volumetric efficiency when the degree of drying of the electrolyte membrane becomes a set value or more.   3. The pump drive control device according to claim 2, wherein the calculation unit calculates the volumetric efficiency after scavenging the fuel gas circulation system after stopping the power generation of the fuel cell. 4.   The calculation means obtains the power consumption of the pump when the rotational speed of the pump is controlled to be constant in the vicinity of the set maximum rotational speed, and based on the obtained power consumption of the pump and the rotational speed of the pump, The pump drive control device according to claim 2 which calculates volumetric efficiency. An inverter connected to the pump;
The output current of the inverter, further comprising a current / voltage detection means for detecting the output voltage,
The pump drive control device according to claim 2, wherein the calculation means obtains power consumption of the pump based on the detected output current and output voltage of the inverter. First pressure detecting means for detecting an inflow pressure of fuel gas flowing into the pump;
A second pressure detecting means for detecting an outflow pressure of the fuel gas flowing out from the pump;
The calculation means obtains the power consumption of the pump when the rotation speed of the pump is controlled to be constant, the obtained power consumption of the pump, the rotation speed of the pump, the detected inflow pressure, and the detected outflow pressure. The pump drive control device according to claim 2, wherein the volumetric efficiency is calculated based on:   The calculation means detects the rotation speed of the pump when the pump is driven with a set power, and calculates the volumetric efficiency based on the detected rotation speed of the pump and power consumption of the pump. 2. The pump drive control device according to 2.

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