JP2007192686A - Precision inspecting method of dew point meter and fuel cell evaluation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a precision inspecting method of a dew point meter capable of inspecting the precision of the dew point meter in a relatively simple manner in a short time, and a fuel cell evaluation device. <P>SOLUTION: In the precision inspection method of the dew point meter, the amount of the moisture in a fluid calculated on the basis of the measured values of the dew point meters 19 and 39 is compared with the amount of the moisture after the gas-liquid separation of the fluid to inspect the precision of the dew point meters. For example, the fuel cell evaluation device is provided with the dew point meters for measuring the dew point of the fluid supplied to a fuel cell 11, gas-liquid separators 21 and 41 for subjecting the fluid after passed through the gas-liquid separators to gas-liquid separation, water condensate tanks 23 and 43 for storing water condensate after separation in the gas-liquid separators, weight meters 26 and 46 for detecting the weights of the water condensate in the water condensate tanks and dew point meter precision inspection means 27 and 47 for comparing the amount of the moisture in the fluid calculated on the basis of the measured values of the dew point meters with the amount of the moisture measured by the weight meters to inspect the precision of the dew point meters. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dew point meter accuracy verification method and a fuel cell evaluation apparatus.

In a fuel cell that generates electricity by the reaction of an oxidizing gas and a fuel gas, the gas is humidified and then supplied to the fuel cell. In order to secure moisture for such humidification, the fuel cell There is a technique for promoting the recovery of moisture from exhaust gas using a cooling means such as a heat exchanger, a heat pipe, or a fin (see, for example, Patent Document 1).
JP 2002-313383 A

  In a fuel cell, the humidity (dew point) of the gas humidified as described above is an important factor that determines the performance. Therefore, in the fuel cell evaluation apparatus for evaluating the performance of the fuel cell, the humidity is supplied to the fuel cell. A dew point meter that measures the dew point of the gas is provided on the inlet side. However, the performance test of the fuel cell has severe environmental conditions for the dew point meter, and the accuracy of the dew point meter may occur when used for a long time.

  For this reason, it was necessary to periodically verify the accuracy of the dew point meter. The accuracy verification of such a dew point meter was conventionally performed by removing the dew point meter from the fuel cell evaluation device and comparing it with a calibration dew point meter or humidity standard generator. The accuracy check and reattachment were necessary, and it took time and effort.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a dew point meter accuracy verification method and a fuel cell evaluation apparatus capable of verifying the accuracy of a dew point meter relatively easily and in a short time. Yes.

  In order to achieve the above object, the dew point meter accuracy verification method of the present invention compares the amount of water in the fluid determined based on the measured value of the dew point meter and the amount of water after gas-liquid separation of the fluid. To verify the accuracy of the dew point meter.

  According to this configuration, the dew point is determined by comparing the amount of water in the fluid determined based on the measured value of the dew point meter with the amount of water after gas-liquid separation of the fluid (actual moisture amount) measured by the dew point meter. In order to verify the accuracy of the meter, for example, by providing a weight meter or the like that detects the amount of water after gas-liquid separation, the accuracy of the dew point meter can be verified without removing the dew point meter. Moreover, since the weight can be measured with high accuracy, high verification accuracy can be obtained.

  The amount of water in the fluid determined based on the measured value of the dew point meter is the dew point meter under the condition that the fluid flowing at a constant flow rate is humidified and the liquid phase temperature and the gas phase temperature are controlled to a constant temperature. It is preferable to obtain | require based on the measured value of said, said flow volume, pressure, and the distribution | circulation time of a fluid.

  According to this configuration, the amount of water in the fluid obtained based on the measured value of the dew point meter is under the condition that the fluid flowing at a constant flow rate is humidified and the liquid phase temperature and the gas phase temperature are controlled to a constant temperature. Since it is calculated | required based on the measured value of a dew point meter, flow volume, pressure, and the distribution | circulation time of a fluid, a moisture content can be calculated | required by easy measurement.

  The fuel cell evaluation apparatus of the present invention includes a dew point meter that measures the dew point of the fluid supplied to the fuel cell, a gas / liquid separator that separates the fluid after passing through the fuel cell, and a gas / liquid separator that separates the fluid. A fuel cell evaluation apparatus having a condensate tank for storing condensate later, a weigh scale for detecting the weight of the condensate in the condensate tank, and a fluid obtained based on the measured value of the dew point meter Dew point meter accuracy verification means for verifying the accuracy of the dew point meter by comparing the amount of water in the water amount with the amount of water measured by the weighing scale is provided.

  According to this configuration, the dew point meter accuracy verification means determines the amount of moisture in the fluid obtained based on the measured value of the dew point meter and the moisture measured by the weigh scale after the gas-liquid separation of the fluid measured by the dew point meter. Since the accuracy of the dew point meter is verified by comparing the amount (actual water content), the accuracy of the dew point meter can be verified without removing or reattaching the dew point meter.

  According to the dew point meter accuracy verification method and fuel cell evaluation apparatus of the present invention, the accuracy of the dew point meter can be verified relatively easily and in a short time because the accuracy can be verified without removing or reattaching the dew point meter. can do.

  Next, an embodiment of a dew point accuracy verification method and a fuel cell evaluation apparatus according to the present invention will be described.

  FIG. 1 shows the overall configuration of a fuel cell evaluation apparatus 10, which is a test apparatus for performing various performance evaluations such as the power generation capability of the fuel cell 11. In the fuel cell evaluation device 10, hydrogen gas as a fuel gas (fluid) is supplied from one side from a hydrogen gas supply source (not shown) such as a hydrogen tank, and the other side is a hydrogen gas supply port of the fuel cell 11. A hydrogen gas supply flow path 12 to be connected and a hydrogen off gas flow path 13 for discharging the hydrogen off gas from the fuel cell 11 connected to the hydrogen off gas discharge port of the fuel cell 11 are provided.

  The hydrogen gas supply channel 12 is provided with a flow meter 15 for detecting the flow rate of the passing hydrogen gas. The hydrogen gas flowing into the fuel cell 11 side of the flow meter 15 is humidified and has a thermometer 16. In addition, a humidifier 17 is provided which can control the liquid phase temperature and the gas phase temperature of hydrogen gas to a constant temperature. The hydrogen gas supply channel 12 is provided with a heater 18 for heating the hydrogen gas closer to the fuel cell 11 than the humidifier 17, and the dew point of the hydrogen gas supplied to the fuel cell 11 closest to the fuel cell 11. A dew point meter 19 for measuring the above is provided.

  In the hydrogen off-gas flow path 13, a heat exchanger 21 as a gas-liquid separator that gas-liquid separates the hydrogen off-gas after passing through the fuel cell 11 is provided closest to the fuel cell 11, and the fuel cell of the heat exchanger 21 is provided. A pressure gauge 22 that detects the pressure of the hydrogen off gas is provided on the side opposite to the pressure gauge 11. The hydrogen off-gas flow path 13 has a condensed water tank 23 for storing condensed water generated by gas-liquid separation in the heat exchanger 21 on the opposite side of the fuel cell 11 from the connection position of the pressure gauge 22. A back pressure valve 24 for controlling the back pressure of the hydrogen off gas is provided on the opposite side of the condensed water tank 23 from the fuel cell 11.

  In the fuel cell evaluation device 10, the cathode side is supplied with air as an oxidizing gas (fluid) from one side from an air supply source (not shown) such as an air compressor, and the other side is connected to the air supply port of the fuel cell 11. An air supply flow path 32 and an air off gas flow path 33 that is connected to the air off gas discharge port of the fuel cell 11 and discharges the air off gas from the fuel cell 11 are provided.

  The air supply flow path 32 is provided with a flow meter 35 for detecting the flow rate of the air passing therethrough. The flow meter 35 humidifies the air flowing into the fuel cell 11 and has a thermometer 36 to provide air. There is provided a humidifier 37 capable of controlling the liquid phase temperature and the gas phase temperature to a constant temperature. The air supply passage 32 is provided with a heater 38 for heating air closer to the fuel cell 11 than the humidifier 37, and measures the dew point of the air supplied to the fuel cell 11 closest to the fuel cell 11. A dew point meter 39 is provided.

  In addition, the air off-gas flow path 33 is provided with a heat exchanger 41 as a gas-liquid separator that gas-liquid separates the air off-gas after passing through the fuel cell 11 on the most fuel cell 11 side. A pressure gauge 42 for detecting the pressure of the air off gas is provided on the side opposite to the fuel cell 11. The heat exchangers 21 and 41 share a part of the configuration.

  The air off-gas flow path 33 is provided with a condensed water tank 43 for storing condensed water generated by gas-liquid separation by the heat exchanger 41 on the opposite side of the fuel cell 11 from the connection position of the pressure gauge 42. In addition, a back pressure valve 44 for controlling the back pressure of the air off gas is provided on the opposite side of the condensed water tank 43 from the fuel cell 11.

  In the fuel cell evaluation device 10 of the present embodiment, first, on the anode side, a weigh scale 26 that detects the weight of the condensed water in the condensed water tank 23 by detecting the weight of the condensed water tank 23, and a dew point meter. The accuracy of the dew point meter 19 is compared by comparing the amount of water in the hydrogen gas obtained based on the measured value of 19 and the amount of water after gas-liquid separation of the hydrogen off-gas detected by the weigh scale 26 (actual moisture amount). A dew point meter accuracy verification device (dew point meter accuracy verification means) 27 for verification is provided.

  Here, the dew point accuracy verification device 27 controls the hydrogen supply side so that the flow rate of the hydrogen gas measured by the flow meter 15 is constant, the humidifier 17 humidifies the hydrogen gas, and the liquid phase. The temperature and gas phase temperature are controlled to a constant temperature. The dew point meter accuracy verification device 27 calculates the measured value from the measured value of the dew point meter 19 under the condition in which the hydrogen gas flowing at a constant flow rate is humidified and the liquid phase temperature and the gas phase temperature are controlled to a constant temperature. The amount of water in the hydrogen gas is determined based on the constant flow rate in the flow meter 15, the pressure detected by the pressure gauge 22, and the hydrogen gas circulation time.

  That is, the dew point meter accuracy verification device 27 performs the following calculation.

  When the flow rate of the hydrogen gas flowing into the humidifier 17 is set to a constant flow rate Q [NL / min], the hydrogen gas is humidified by the humidifier 17 and the liquid phase temperature and the gas phase temperature are controlled to a constant temperature. The amount of water per unit time is constant. Further, the hydrogen gas is allowed to flow for a predetermined verification time in this way, and the time T [min] from the start of flow to the end of flow is measured. Further, the measured value X [° C.] of the dew point meter 19 and the measured value P [kPa] of the pressure gauge when the hydrogen gas is flowing are confirmed.

And based on the above, the moisture content based on the measured value of the dew point meter 19 is calculated from the following calculation formula.

In the above equation (1), the amount of water taken away can be ignored if the hydrogen off-gas temperature is cooled to near 0 [° C.] by the heat exchanger 21. The saturated vapor pressure can be expressed as a function of dew point as follows:

  The measured value (that is, the display value) X of the dew point meter 19 is substituted into the above equation (2) to obtain the saturated vapor pressure, and this saturated vapor pressure is substituted into the equation (1). Thereby, the moisture content in the hydrogen gas obtained based on the measured value of the dew point meter 19 is obtained.

  The dew point meter accuracy verification device 27 subtracts the actual moisture amount detected by the weigh scale 26 from the start of the flow until the end of the predetermined verification time (the weight at the start of the flow from the weight at the end of the flow). Increase) and the amount of water in the hydrogen gas obtained based on the measurement value of the dew point meter 19 described above, and when these differences are within a predetermined allowable range set in advance, the dew point meter If it is determined that the accuracy of 19 is outside the predetermined allowable range, it is determined that the accuracy of the dew point meter 19 is not appropriate and an alarm is generated. The dew point meter accuracy verification device 27 automatically performs such verification at an appropriate timing or by an instruction operation by the operator.

  As described above, the water content in the hydrogen gas obtained based on the measurement value of the dew point meter 19 is compared with the water content after gas-liquid separation of the hydrogen gas (actual water content) measured by the dew point meter 19. In order to verify the accuracy of the dew point meter 19, the accuracy of the dew point meter 19 can be verified without removing or reattaching the dew point meter 19 by providing a weight meter 26 that detects the amount of water. Therefore, the accuracy of the dew point meter 19 can be verified relatively easily and in a short time. Moreover, since the weight can be measured with high accuracy, high verification accuracy can be obtained.

  Also, the dew point under the condition that the moisture content in the hydrogen gas obtained based on the measured value of the dew point meter 19 humidifies the hydrogen gas flowing at a constant flow rate and controls the liquid phase temperature and the gas phase temperature to a constant temperature. Since it is calculated | required based on the measured value X of the meter 19, the flow volume Q, the pressure P, and the distribution | circulation time T of hydrogen gas, this moisture content can be calculated | required by easy measurement.

  In the above description, the anode side has been described. However, a weight meter that detects the weight of the condensed water in the condensed water tank 43 by detecting the weight of the condensed water tank 43 on the cathode side as well as the anode side. 46 and the measured value of the dew point meter 39 under the condition that the air flow rate measured by the flow meter 35 is constant, the air is humidified by the humidifier 37 and the liquid phase temperature and the gas phase temperature are controlled to a constant temperature. The amount of water determined based on the constant flow rate at the flow meter 35, the pressure detected by the pressure meter 42, and the air circulation time, and the water amount after gas-liquid separation of the air off-gas detected by the weight meter 46 And a dew point meter accuracy verifying device (dew point meter accuracy verifying means) 47 for verifying the accuracy of the dew point meter 39 is provided.

  Here, since the dew point meter accuracy verification device 47 performs verification in the same manner as the anode side, the verification will be omitted, but the same effect as that on the anode side will be achieved.

  In the fuel cell evaluation device 10 described above, the dew point accuracy verification devices 27 and 47 are automatically detected by the moisture content in the gas and the weight meters 26 and 46 which are obtained based on the measured values of the dew point meters 19 and 39. The case where the accuracy of the dew point meters 19 and 39 is verified by comparing with the amount of water after gas-liquid separation of the gas has been described as an example, but the humidifiers 17 and 37, the dew point meter 19 and the fuel cell evaluation device 10 are required. 39, heat exchangers 21, 41, pressure gauges 22, 42, condensate water tanks 23, 43, etc., with addition of weight gauges 26, 46, and the same dew point as the above dew point meter accuracy verification devices 27, 47 A total of 19, 39 verifications can be performed manually.

  In this case, since only the weigh scales 26 and 46 need be added to the fuel cell evaluation apparatus 10, there is an advantage that accuracy can be confirmed at low cost.

The schematic block diagram of the fuel cell evaluation apparatus shown as one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell evaluation apparatus, 11 ... Fuel cell, 19, 39 ... Dew point meter, 21, 41 ... Heat exchanger (gas-liquid separator), 23, 43 ... Condensed water tank, 26, 46 ... Weight meter, 27, 47. Dew point meter accuracy verification device (dew point meter accuracy verification means).

Claims (3)

  An accuracy verification method for a dew point meter that verifies the accuracy of the dew point meter by comparing the amount of water in the fluid obtained based on the measured value of the dew point meter and the amount of water after gas-liquid separation of the fluid. A method of verifying accuracy of a dew point meter according to claim 1,
The amount of water in the fluid determined based on the measured value of the dew point meter is measured by the dew point meter under conditions where the fluid flowing at a constant flow rate is humidified and the liquid phase temperature and the gas phase temperature are controlled to a constant temperature. A method for verifying the accuracy of a dew point meter determined based on the value, the flow rate, the pressure, and the fluid circulation time. A dew point meter that measures the dew point of the fluid supplied to the fuel cell, a gas / liquid separator that separates the fluid after passing through the fuel cell, and a condensed water that stores the condensed water separated by the gas / liquid separator A fuel cell evaluation device having a tank,
A weigh scale for detecting the weight of the condensed water in the condensed water tank;
Dew point meter accuracy verification means for verifying the accuracy of the dew point meter by comparing the amount of water in the fluid obtained based on the measurement value of the dew point meter and the amount of water measured by the weight meter is provided. Fuel cell evaluation device.

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