JP3900345B2 - Power measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power measuring device, and more particularly to a power measuring device that measures the efficiency of a fuel cell.
[0002]
[Prior art]
With the development of fuel cells, the need for evaluation of fuel cells is increasing.
Conventionally, impedance measurement or the like has been performed as an evaluation item of the fuel cell, and there is a patent document by the present applicant. (For example, see Patent Document 1)
In addition to this, the measurement of fuel cell efficiency is also a very important item for evaluation. This efficiency measurement will be described with reference to the drawings.
[0003]
FIG. 4 is a diagram showing an example of a conventional power measuring apparatus applied to a fuel cell efficiency measuring system.
The solid line arrows in the figure indicate the flow of hydrogen gas, the broken line arrows indicate the flow of electrical signals output from the flowmeter and the power measuring instrument, and the thick solid line indicates the flow of electrical energy.
[0004]
The hydrogen fuel supply source 41 is composed of, for example, a hydrogen storage tank and supplies hydrogen fuel to the fuel cell 42. The fuel cell 42 generates electric power by reacting the supplied hydrogen and oxygen in the air. The first flow meter 43 detects the flow rate of hydrogen supplied to the fuel cell 42 and outputs an electrical signal corresponding to the detected amount to the arithmetic device 44. The second flow meter 45 detects the flow rate of hydrogen remaining without being consumed by the fuel cell 42 and similarly outputs the result to the arithmetic device 44 as an electrical signal.
[0005]
The hydrogen fuel recovery device 46 recovers surplus hydrogen, and the recovered hydrogen fuel is reused as the supply fuel. The electronic load device 47 is a load that consumes electrical energy obtained as the output of the fuel cell 42. The power measuring device 48 measures the consumed power based on the voltage and current output from the fuel cell 42 and outputs the measurement result to the computing device 44. The calculation device 44 is composed of a personal computer or the like, and calculates the amount of hydrogen consumed as fuel from the difference between the detection results of the flow meters 43 and 45 to calculate the input energy.
Also, the output energy is calculated from the consumed power, and the efficiency of the fuel cell is calculated.
The arithmetic device 44 displays the amount of hydrogen, input / output energy, efficiency value, and the like, and also controls each flow meter, the power measuring device 48, and the like.
[0006]
[Patent Document 1]
Japanese Patent Application 2001-207552
[0007]
[Problems to be solved by the invention]
In the conventional configuration, the arithmetic unit calculates the efficiency based on the electrical signal output from each flow meter and the electrical signal output from the power measurement device. For this reason, since the data output interval and timing do not match between the electrical signal obtained from the flow meter and the electrical signal obtained from the power measuring device, it is difficult to synchronize and it is difficult to measure the efficiency with high accuracy. . Further, a separate arithmetic unit is required for measuring the efficiency of the fuel cell, and there is a problem that the efficiency cannot be easily measured.
[0008]
The present invention has been made to solve the above-described problems, and by calculating flow data corresponding to input energy supplied to a fuel cell and power data corresponding to output energy by a power measuring device, It is an object of the present invention to provide a power measuring apparatus that can synchronize each data, improve the measurement accuracy, and can easily measure the efficiency without requiring a separate arithmetic unit.
[0009]
[Means for Solving the Problems]
The present invention is a power measuring apparatus configured as follows.
[0011]
(1) A flow rate of hydrogen fuel supplied to a fuel cell that generates power based on output signals from first and second flow meters installed in advance, and a flow rate of hydrogen fuel discharged from the fuel cell. A sensor output detector for detecting;
An input energy conversion unit that calculates the input energy of the hydrogen fuel consumed in the fuel cell from the difference in flow rate detection results of the sensor output detection unit;
A power measuring unit for measuring the power output from the fuel cell;
An output energy conversion unit for calculating output energy from the measured power;
An efficiency calculator that calculates efficiency from the ratio of the input energy and the output energy;
A power measuring apparatus that corrects a delay of an output signal of the flow meter .
[0012]
(2) The input energy conversion unit
A hydrogen amount conversion unit for converting the output signal of the flow meter into a hydrogen amount;
A reaction energy calculation unit for calculating energy corresponding to the converted hydrogen amount;
(1) The power measuring device according to (1) .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing an embodiment of the present invention.
In FIG. 1, a sensor output detection unit 1 detects analog signals and the like output from the first and second flow meters described above, and outputs a voltage signal to the signal amplification unit 2.
For example, a mass flow sensor or the like is used as the flow meter.
The signal amplifier 2 amplifies or attenuates the input voltage signal, normalizes it, and outputs it to the digital converter 3. The digital conversion unit 3 converts the normalized voltage value into digital data.
[0014]
The power measurement unit 4 measures the voltage and current output from the fuel cell, calculates power, and outputs the power data to the output energy conversion unit 5. The output energy conversion unit 5 converts the power data output from the power measurement unit 4 into output energy.
[0015]
The input energy conversion unit 6 includes a hydrogen amount conversion unit 61 and a reaction energy calculation unit 62. The hydrogen amount conversion unit 61 is preset with hydrogen amount data corresponding to digital data by calibration. The digital data output from can be converted into the amount of hydrogen. The reaction energy calculation unit 62 calculates the difference between the converted hydrogen amount of the first flow meter (hydrogen amount supplied to the fuel cell) and the hydrogen amount of the second flow meter (hydrogen amount discharged from the fuel cell). The input energy is obtained by calculating the reaction energy of hydrogen reacted in the fuel cell. Since the heat of combustion per unit mass of hydrogen is known, if the mass is known, it can be converted into energy.
The efficiency calculator 7 calculates the efficiency of the fuel cell from the ratio of input energy to output energy.
The calculation result output unit 8 displays the result of the efficiency calculation or outputs it as a standardized electrical signal.
[0016]
Thereby, since the output data of a flowmeter can be acquired directly with an electric power measurement apparatus, it can synchronize easily with electric power data. Even if there is a delay in the output data of the flow meter, if this delay time is known, it can be easily corrected.
[0017]
The power measuring apparatus of the present invention has functions provided in a conventional power measuring apparatus such as an operation means operated by a user and multi-channel measurement.
[0018]
FIG. 2 is a configuration diagram showing an example of a power measuring device according to the present invention applied to a fuel cell efficiency measuring system.
In FIG. 2, the same parts as those in the previous figure are designated by the same reference numerals and the description thereof is omitted.
[0019]
2 is different from the conventional example of FIG. 4 in that an electric signal output corresponding to the amount of hydrogen obtained from the first and second flow meters 43 and 45 is input to the power measuring device 50 instead of the computing device 44 described above. Is Rukoto.
The power measuring device 50 has a function of calculating the amount of hydrogen consumed in the fuel cell 42 from the electric signal outputs of the first and second flow meters 43 and 45 as described above, and converting it into the input energy of the fuel cell 42. Have. Further, the output energy is converted by calculating the power value from the voltage value and current value output from the fuel cell 42 as a conventional function. The power measuring device 50 can calculate the energy input / output efficiency of the fuel cell 42 based on the ratio of the input energy and the output energy.
[0020]
As described above, in addition to the function of the conventional power measuring device, the input energy to the fuel cell can be calculated based on the electric signal output of the flow meter used for detecting the hydrogen amount. It is possible to calculate the input / output efficiency. In addition, since the input energy signal and the output energy signal can be synchronized, highly accurate efficiency measurement can be realized. Furthermore, an arithmetic unit is not required, and the efficiency can be measured easily.
[0021]
FIG. 3 shows another embodiment of a fuel cell efficiency measuring system to which the power measuring device of the present invention is applied.
In FIG. 3, the same parts as those in the previous figure are designated by the same reference numerals and the description thereof is omitted.
[0022]
The inverter 51 converts the DC energy output from the fuel cell 42 into easy-to-use AC energy. This is a general use example of the fuel cell 42. FIG. 3 shows an example when the power measuring apparatus 50 is applied to the system.
[0023]
In the conventional power measuring device, it was possible to measure the efficiency between the input and output of the inverter. However, since the input energy of the fuel cell could not be measured, it was difficult to measure the total efficiency including the fuel cell. Since the input energy of the fuel cell can be calculated by the power measuring device of the present invention, the efficiency of the system combining the fuel cell and the inverter can also be measured.
[0024]
【The invention's effect】
The present invention has the following effects.
[0025]
According to the invention described in claims 1 to 2, input of addition to the functions of the power measuring instrument from conventional, the difference between the detection results of the two flow meters used to detect the amount of hydrogen to the fuel cell Since energy can be calculated, the input / output efficiency of the fuel cell can be calculated by the power measuring device. In addition, since each signal processing and calculation processing is performed by one power measuring device, the input energy signal and the output energy signal can be synchronized, and highly accurate efficiency measurement can be realized. Furthermore, an arithmetic unit is not required, and the efficiency can be measured easily.
[0026]
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of the present invention.
FIG. 2 is a block diagram showing an embodiment of a fuel cell efficiency measuring system to which the power measuring device of the present invention is applied.
FIG. 3 is a configuration diagram showing another embodiment of a fuel cell efficiency measuring system to which the power measuring apparatus of the present invention is applied.
FIG. 4 is a configuration diagram showing an example of a fuel cell efficiency measurement system to which a conventional power measurement device is applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sensor output detection part 4 Electric power measurement part 5 Output energy conversion part 6 Input energy conversion part 7 Efficiency calculation part

Claims (2)

A sensor for detecting a flow rate of hydrogen fuel supplied to a fuel cell that generates electric power based on output signals from first and second flow meters installed in advance and a flow rate of hydrogen fuel discharged from the fuel cell. An output detector;
An input energy conversion unit for calculating input energy of hydrogen fuel consumed in the fuel cell from a difference in flow rate detection result of the sensor output detection unit;
A power measuring unit for measuring the power output from the fuel cell;
An output energy conversion unit for calculating output energy from the measured power;
An efficiency calculator that calculates efficiency from the ratio of the input energy and the output energy;
A power measuring apparatus that corrects a delay of an output signal of the flow meter . The input energy conversion unit is
A hydrogen amount conversion unit for converting the output signal of the flow meter into a hydrogen amount;
A reaction energy calculation unit for calculating energy corresponding to the converted hydrogen amount;
The power measuring device according to claim 1 , wherein

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