JP2007134287A - Estimation device and estimation method of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an estimation device and an estimation method of a fuel cell capable of exactly grasping water balance of the fuel cell. <P>SOLUTION: A measuring means 101 measures entrance and exit of water to and from the fuel cell. A water balance calculation means 102 calculates water balance on the basis of result of calculation at the measuring means 101. A generated water quantity calculation means 103 calculates quantity of the water generated by power generation of the fuel cell. In this case, the water balance calculation means 102 can calculate the water balance by modifying it with the calculation result of the generated water quantity calculation means 103. A control means 104 controls the water balance of the fuel cell in compliance with the calculation result of the water balance calculation means 102. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell evaluation device and an evaluation method for evaluating an operating state of a fuel cell, and more particularly to an evaluation device and an evaluation method capable of evaluating a water balance of a fuel cell.

  2. Description of the Related Art Fuel cells that supply power by generating fuel gas and oxidizing gas are known. In order to operate the fuel cell efficiently and stably, the management of the water balance, which is the flow of water into and out of the fuel cell, is an important factor. Since the water balance changes according to the humidity of the supply gas applied to the fuel cell, a method for controlling the humidity of the supply gas includes a method of adjusting the amount of wet gas mixed with the dry gas. The wet gas mixed with the dry gas is generated by adding water vapor to the supply gas using a humidifier.

Special Table 2002-535806 JP 2005-285610 A

  Conventionally, when managing the water balance of a fuel cell, a method of measuring and managing the humidity or dew point at the inlet of the fuel cell that supplies the supply gas or the outlet of the humidifier is employed. However, this method has a problem that the water balance of the fuel cell cannot be directly grasped.

  Managing the water balance at the anode and cathode in a fuel cell is important for stable power generation or maintaining the durability of the fuel cell. Furthermore, by accurately controlling the water balance of the fuel cell, it is possible to avoid drying and flooding of the fuel cell, and by evaluating the fuel cell in an environment where the water balance is controlled, It is possible to accurately grasp the characteristics of the.

  The objective of this invention is providing the evaluation apparatus and evaluation method of a fuel cell which can grasp | ascertain the water balance of a fuel cell correctly.

A fuel cell evaluation apparatus according to the present invention is a fuel cell evaluation apparatus for evaluating an operation state of a fuel cell, a measuring means for measuring the flow of moisture into and out of the fuel cell, and a water balance based on a measurement result by the measuring means. And a water balance calculating means for calculating.
According to this evaluation apparatus, since the water in / out of the fuel cell is measured and the water balance of the fuel cell is calculated based on the result, the water balance can be accurately grasped.

  The measuring means may measure the amount of water supplied to the fuel cell.

  The measuring means may measure the amount of water discharged from the fuel cell.

  A generated water amount calculating means for calculating the amount of water generated by power generation of the fuel cell may be provided, and the water balance calculating means may calculate the water balance in consideration of the calculation result of the generated water amount calculating means.

  The measuring means may measure moisture in and out of the fuel cell for the cathode and the anode, respectively.

Control means may be provided for controlling the water in and out of the fuel cell according to the calculation result by the water balance calculation means.
In this case, the fuel cell can be operated in a state where the water balance of the fuel cell is properly maintained.

The fuel cell evaluation method according to the present invention is a fuel cell evaluation method for evaluating the operating state of a fuel cell. The method includes a step of measuring moisture in and out of the fuel cell, and a water balance based on a measurement result of the measurement step. And a step of calculating.
According to this evaluation method, since the water flow in and out of the fuel cell is measured and the water balance of the fuel cell is calculated based on the result, the water balance can be accurately grasped.

  In the measuring step, the amount of water supplied to the fuel cell may be measured.

  In the measuring step, the amount of water discharged from the fuel cell may be measured.

  A step of calculating the amount of water generated by power generation of the fuel cell, and the step of calculating the water balance may calculate the water balance by taking into account the calculation result of the step of calculating the amount of water generated Good.

  In the measuring step, the moisture in / out of the fuel cell may be measured for the cathode and the anode, respectively.

You may provide the step which controls the entrance / exit of the water | moisture content to the fuel cell according to the calculation result by the step which calculates the said water balance.
In this case, the fuel cell can be operated in a state where the water balance of the fuel cell is properly maintained.

  According to the fuel cell evaluation apparatus of the present invention, the water balance in the fuel cell is measured and the water balance of the fuel cell is calculated based on the result, so that the water balance can be accurately grasped.

  According to the fuel cell evaluation method of the present invention, the amount of water entering and exiting the fuel cell is measured, and the water balance of the fuel cell is calculated based on the result, so that the water balance can be accurately grasped.

  FIG. 1 is a functional block diagram of a fuel cell evaluation apparatus according to the present invention.

  In FIG. 1, a measuring means 101 measures the entry and exit of moisture from the fuel cell. The water balance calculation unit 102 calculates the water balance based on the measurement result by the measurement unit 101.

  Further, the generated water amount calculation means 103 calculates the amount of water generated by the power generation of the fuel cell. In this case, the water balance calculation means 102 can calculate the water balance in consideration of the calculation result of the generated water amount calculation means 103.

  The control unit 104 controls the entry / exit of water to / from the fuel cell according to the calculation result by the water balance calculation unit 102.

  Hereinafter, an embodiment of a fuel cell evaluation apparatus according to the present invention will be described with reference to FIGS.

  FIG. 2 is a block diagram showing the configuration of the evaluation apparatus of this embodiment and the gas supply system for supplying gas to the fuel cell to be evaluated.

  As shown in FIG. 2, the oxidizing gas is supplied from the oxidizing gas supply device 2 to the cathode 11 of the fuel cell 1. The oxidizing gas supply device 2 includes an oxidizing gas supply source 21 that supplies oxidizing gas, a dry gas flow controller 22 that controls the dry flow rate of oxidizing gas, and a wet gas flow controller 23 that controls the wet flow rate of oxidizing gas, A humidifier 24 such as a bubbler for humidifying the oxidizing gas supplied from the wet gas flow controller 23.

  The fuel gas is supplied to the anode 12 of the fuel cell 1 by the fuel gas supply device 3. The fuel gas supply device 3 includes a fuel gas supply source 31 that supplies fuel gas, a dry gas flow rate controller 32 that controls the dry flow rate of the fuel gas, and a wet gas flow rate controller 33 that controls the wet flow rate of the fuel gas. A humidifier 34 such as a bubbler for humidifying the fuel gas supplied from the wet gas flow controller 33.

  The evaluation apparatus 100 according to the present embodiment includes a detection unit 51 for detecting the humidity, pressure, and temperature of the oxidizing gas supplied from the oxidizing gas supply device 2 to the cathode 11, and the gas and liquid discharged from the cathode 11. Gas / liquid separator 52 to be separated, water level meter 53 for measuring the amount of water separated by gas / liquid separator 52, water meter 53 such as a mass meter, and the humidity, pressure and temperature of exhaust gas discharged from cathode 11 The detecting unit 54 for detecting, the detecting unit 61 for detecting the humidity, pressure and temperature of the fuel gas supplied from the fuel gas supply device 3 to the anode 12, and the gas and liquid discharged from the anode 12 are separated. Humidity, pressure and temperature of the exhaust gas exhausted from the gas-liquid separator 62, a water meter 63 for measuring the amount of water separated by the gas-liquid separator 62, a mass meter and the like, and the anode 12 A detection unit 64 for detecting, an electronic load 4 connected between the cathode 11 and the anode 12 for consuming a desired current from the fuel cell, a current measuring device 71 for detecting a consumption current flowing through the electronic load 4, Is provided.

  FIG. 3 is a block diagram showing the configuration of the control system of the evaluation apparatus of this embodiment.

  As illustrated in FIG. 3, the evaluation apparatus 100 according to the present embodiment is based on information from the detection unit 51, the detection unit 54, the detection unit 61, the detection unit 64, the water meter 53, the water meter 63, and the current measuring device 71. And a control unit 73 for controlling the detection unit 51, the detection unit 54, the detection unit 61, the detection unit 64, the water meter 53, the water meter 63, the current measuring device 71, the calculation unit 72, and the electronic load 4. And comprising.

  Further, the evaluation apparatus 100 transmits the dry gas flow rate of the oxidizing gas, the dry gas flow rate controller 23, the wet gas flow rate controller 23, the dry gas flow rate controller 32, and the wet gas flow rate controller 33, respectively. Wet gas flow, fuel gas dry gas and fuel gas wet gas flow are received.

  Next, the calculation procedure of the water balance in the evaluation apparatus 100 will be described.

  FIG. 4 is a flowchart showing the calculation procedure. This procedure is executed in the calculation unit 72 based on the control of the control unit 73. 5 to 8 are diagrams for explaining the calculation procedure.

  In step S1 of FIG. 4, as shown in FIG. 5, the dry gas flow rate sent from the dry gas flow rate controller 22 and the wet gas flow rate sent from the wet gas flow rate controller 23 are added, and the oxidizing gas supply flow rate is added. Is calculated. The oxidizing gas supply flow rate is equal to the supply amount of the oxidizing gas supply source 21.

  Next, in step S2, as shown in FIG. 5, a calculation based on the humidity, pressure, and temperature of the supplied oxidizing gas detected by the detecting unit 51 is performed, and the gas partial pressure of the oxidizing gas supplied to the cathode 11 is calculated. Calculate the water vapor partial pressure and the water vapor flow rate.

  Next, in step S3, as shown in FIG. 5, the dry gas flow rate transmitted from the dry gas flow rate controller 32 and the wet gas flow rate transmitted from the wet gas flow rate controller 33 are added, and the fuel gas supply flow rate is added. Is calculated. The fuel gas supply flow rate is equal to the supply amount of the fuel gas supply source 31.

  Next, in step S4, as shown in FIG. 5, the calculation based on the humidity, pressure and temperature of the supplied fuel gas detected by the detector 61 is executed, and the gas partial pressure of the fuel gas supplied to the anode 12 is Calculate the water vapor partial pressure and the water vapor flow rate.

  In step S5, as shown in FIG. 6, based on the current value measured by the current meter 71, the flow rate of the oxidizing gas consumed by the fuel cell 1, the flow rate of the fuel gas, and the amount of water generated by power generation are calculated. To do.

  Next, in step S6, as shown in FIG. 7, the oxidizing gas flow rate consumed in the fuel cell 1 calculated in step S5 is subtracted from the oxidizing gas supply flow rate calculated in step S1, and then discharged from the fuel cell 1. The oxidant gas flow rate is calculated.

  In step S7, as shown in FIG. 7, the calculation based on the flow rate of the oxidizing gas discharged from the fuel cell 1 and the humidity, pressure, and temperature of the exhaust oxidizing gas detected by the detection unit 54 obtained in step S6. To calculate the partial pressure of the gas exhausted from the cathode 11, the partial pressure of water vapor, and the flow rate of water vapor.

  Next, in step S8, as shown in FIG. 7, the fuel gas flow rate consumed in the fuel cell 1 calculated in step S5 is subtracted from the fuel gas supply flow rate calculated in step S3, and then discharged from the fuel cell 1. The fuel gas flow rate is calculated.

  In step S9, as shown in FIG. 7, the calculation based on the flow rate of the fuel gas discharged from the fuel cell 1 obtained in step S8 and the humidity, pressure and temperature of the exhaust fuel gas detected by the detector 64. And the partial pressure of the gas exhausted from the anode 12, the partial pressure of water vapor, and the flow rate of water vapor are calculated.

  Next, in step S10, as shown in FIG. 8, the cathode supply water vapor flow rate calculated in step S2, the anode supply water vapor flow rate calculated in step S4, and the water amount generated by power generation calculated in step S5 are added. Then, the sum of the amount of water supplied to the fuel cell 1 and the amount of water generated by power generation in the fuel cell 1 is calculated.

  Next, in step S11, as shown in FIG. 8, the flow rate of exhaust water vapor from the cathode 11 calculated in step S7, the amount of discharged water from the cathode 11 measured by the water meter 53, and the flow rate from the anode 12 calculated in step S9. The sum of the amount of water discharged from the fuel cell 11 is calculated by adding the exhaust water vapor flow rate and the amount of water discharged from the anode 12 measured by the water meter 63.

  Next, in step S12, as shown in FIG. 8, the sum of the amount of water supplied to the fuel cell 1 calculated in step S10 and the amount of water generated by power generation in the fuel cell 1, and the fuel calculated in step S11. A process of comparing the total amount of water discharged from the battery 11 is executed.

  FIG. 9 is a flowchart showing the processing procedure of step S12. As shown in FIG. 9, after completing the process of step S <b> 11, in step S <b> 121, the sum of the amount of water supplied to the fuel cell 1 and the amount of water generated by the fuel cell 1 is the water discharged from the fuel cell 11. It is determined whether or not the sum is greater than the total amount. If the determination is affirmative, it is determined in step S122 that the moisture in the fuel cell 1 is in an increasing tendency, and the process proceeds to step S13. If the determination in step S121 is negative, the process proceeds to step S123.

  In step S123, it is determined whether or not the sum of the amount of water supplied to the fuel cell 1 and the amount of water generated by the fuel cell 1 is smaller than the sum of the amount of water discharged from the fuel cell 11, and the determination is affirmative. If so, it is determined in step S124 that the moisture in the fuel cell 1 tends to decrease, and the process proceeds to step S13. If the determination in step S123 is negative, the process proceeds to step S125.

  In step S125, it is determined that the water balance of the fuel cell 1 is good, and the process proceeds to step S13. The process proceeds to step S125 when the sum of the amount of moisture supplied to the fuel cell 1 and the amount of moisture generated by the fuel cell 1 is equal to the sum of the amount of moisture discharged from the fuel cell 11.

  As shown in FIG. 4, in step S13, the determination result in the process of step S12 is output, and a series of processing procedures is terminated.

  As described above, according to the evaluation apparatus of the present embodiment, the amount of water supplied to the fuel cell, the amount of water generated by the fuel cell, and the amount of water discharged from the fuel cell are calculated and based on these values. The state of water coming in and out. For this reason, the water balance of the fuel cell 1 can be accurately grasped. In the present embodiment, the sum of the water in and out of the cathode and anode is calculated as the water balance of the fuel cell. For this reason, the water balance including the influence of the back diffusion to the anode of the generated water produced | generated by electric power generation can be grasped | ascertained correctly.

  In the above embodiment, when calculating the flow rate of the exhaust gas, the amount of gas consumed in the fuel cell is subtracted from the amount of gas supplied to the fuel cell (step S6 and step S8). However, the flow rate of the gas exhausted from the fuel cell may be directly measured using a flow meter or the like. In this case, when calculating the flow rate of the exhaust gas, there is no need to use the measured value of the current consumption.

  Moreover, in the said embodiment, the gas-liquid separator is provided in the exhaust side of the fuel cell 1, and gas and water are isolate | separated. However, a heating device may be provided in place of the gas-liquid separator, and the humidity, pressure, and temperature of the exhaust gas may be measured after all of the discharged moisture is converted to steam. The amount of moisture discharged from the fuel cell can be calculated using this measured value.

  In general, in the operation of a fuel cell, in order to improve the power generation characteristics, the operation in a pressurized environment may be executed. For example, the pressure of the gas supplied to the fuel cell is controlled by installing a pressure regulating valve on the gas supply side, or the pressure or fuel of the gas supplied to the fuel cell by installing a pressure control valve on the exhaust side The pressure of the gas discharged from the battery can be controlled. The evaluation apparatus of the present embodiment can accurately grasp the water balance of the fuel cell even when the operation is performed in such a pressurized environment.

  A gas supply system for a fuel cell can be configured using the evaluation apparatus according to the present invention.

  FIG. 10 is a block diagram showing a configuration of a gas supply system using the evaluation apparatus.

  As shown in FIG. 10, the gas supply system includes a control device 8 that controls the oxidizing gas supply device 2 and the fuel gas supply device 3.

  The control device 8 receives the determination result of the water balance by the evaluation device 100 of the above embodiment and controls the oxidizing gas supply device 2 and the fuel gas supply device 3 to maintain the water balance well or to operate the fuel cell. Optimize state. As the control by the control device 8, for example, the water content of the fuel cell 1 can be controlled by controlling the ratio of dry gas to wet gas in the supply gas. Further, when it is determined that the amount of water in the fuel cell 1 has increased, it is possible to perform control such that the gas supply amount is increased to facilitate the discharge of moisture.

  As described above, according to the fuel cell evaluation device and the evaluation method of the present invention, the water balance of the fuel cell is calculated based on the result of measuring the water flow in and out of the fuel cell. Can grasp.

  Further, as shown in FIG. 10, by controlling the flow of water into and out of the fuel cell according to the calculation result of the water balance, the fuel cell can be operated with the water balance properly maintained.

  The scope of application of the present invention is not limited to the above embodiment. The present invention can be widely applied to an evaluation apparatus and an evaluation method for a fuel cell that evaluates the operating state of the fuel cell.

The block diagram which shows the evaluation apparatus of the fuel cell by this invention functionally. The block diagram which shows the structure of the system which supplies the gas with respect to the evaluation apparatus of this embodiment, and the fuel cell used as evaluation object. The block diagram which shows the structure of the control system of the evaluation apparatus of this embodiment. The flowchart which shows a calculation procedure. The figure explaining a calculation procedure. The figure explaining a calculation procedure. The figure explaining a calculation procedure. The figure explaining a calculation procedure. The flowchart which shows the process sequence of step S12. The block diagram which shows the structure of the gas supply system using an evaluation apparatus.

Explanation of symbols

8 Control device (control means)
22 Dry gas flow controller (measuring means)
23 Wet gas flow controller (measuring means)
32 Dry gas flow controller (measuring means)
33 Wet gas flow controller (measuring means)
51 Detector (Measuring means)
54 Detector (Measuring means)
61 Detection part (measuring means)
64 detector (measuring means)
71 Current measuring device (Production water amount calculation means)
73 calculating part (water balance calculating means, generated water amount calculating means)
DESCRIPTION OF SYMBOLS 101 Measurement means 102 Water balance calculation means 103 Generated water amount calculation means 104 Control means

Claims (12)

In a fuel cell evaluation apparatus for evaluating the operating state of a fuel cell,
A measuring means for measuring moisture in and out of the fuel cell;
Water balance calculation means for calculating a water balance based on the measurement result by the measurement means;
A fuel cell evaluation apparatus comprising: 2. The fuel cell evaluation apparatus according to claim 1, wherein the measuring means measures the amount of water supplied to the fuel cell. The fuel cell evaluation apparatus according to claim 1, wherein the measuring unit measures the amount of water discharged from the fuel cell. Provided with a generated water amount calculating means for calculating the amount of water generated by the power generation of the fuel cell;
4. The fuel cell evaluation apparatus according to claim 1, wherein the water balance calculation unit calculates a water balance in consideration of a calculation result of the generated water amount calculation unit. 5. 5. The fuel cell evaluation apparatus according to claim 1, wherein the measuring unit measures the entry and exit of water into and from the fuel cell with respect to the cathode and the anode, respectively. 6. The fuel cell evaluation apparatus according to claim 1, further comprising a control unit configured to control water in and out of the fuel cell in accordance with a calculation result by the water balance calculation unit. In the fuel cell evaluation method for evaluating the operating state of the fuel cell,
Measuring the entry and exit of moisture into the fuel cell;
Calculating a water balance based on a measurement result of the measuring step;
A method for evaluating a fuel cell, comprising: The fuel cell evaluation method according to claim 7, wherein in the measuring step, the amount of water supplied to the fuel cell is measured. The fuel cell evaluation method according to claim 7 or 8, wherein in the measuring step, the amount of water discharged from the fuel cell is measured. Calculating the amount of water generated by power generation of the fuel cell,
The fuel according to any one of claims 7 to 9, wherein in the step of calculating the water balance, a water balance is calculated in consideration of a calculation result of the step of calculating the amount of water generated. Battery evaluation method. The method for evaluating a fuel cell according to any one of claims 7 to 10, wherein, in the measuring step, the flow of water into and out of the fuel cell is measured for each of the cathode and the anode. The method for evaluating a fuel cell according to any one of claims 7 to 11, further comprising a step of controlling the flow of water into and out of the fuel cell according to a calculation result of the step of calculating the water balance.

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