JP5408969B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system.

  An electrolyte membrane used in a fuel cell exhibits good proton conductivity in a wet state. Therefore, it is preferable that the inside of the fuel cell during power generation is maintained in a moderately wet state. Therefore, some fuel cell systems detect the dew point temperature of the reaction gas in order to control the humidification amount while supplying the humidified reaction gas to the fuel cell (Patent Document 1, etc.).

JP 2004-047154 A JP 2003-346855 A

  By the way, in general, in order to detect the dew point temperature of the reaction gas, the reaction gas is detected after the temperature of the reaction gas is raised to a certain level (for example, 20 ° C.). However, when the temperature of the reaction gas is significantly higher than the dew point temperature (for example, about 30 ° C. higher than the dew point temperature), the sensor element may be deteriorated by heat from the reaction gas. Such a problem is not limited to the case where the dew point temperature of the reaction gas supplied to the fuel cell is measured, but is a problem common to the case where the gas dew point temperature is measured. However, until now, it has been the actual situation that such a problem has not been sufficiently devised.

  An object of this invention is to provide the technique which suppresses that the sensor element for measuring the dew point temperature of gas deteriorates in a fuel cell system.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A fuel cell system, comprising: first and second branch pipes that are provided in a gas pipe connected to a fuel cell and branch in parallel; and a dew point temperature of a measurement target gas that flows into the first branch pipe. And a dew point temperature detection unit for detecting, wherein the second branch pipe functions as a bypass pipe for bypassing part or all of the measurement target gas from the first branch pipe.
According to this fuel cell system, the gas amount of the measurement target gas supplied to the dew point temperature detection unit can be reduced by the amount bypassed to the second branch pipe. Therefore, since the dew point temperature detection part can reduce the load received from measurement object gas, it can suppress that the sensor element for measuring dew point temperature deteriorates.

[Application Example 2]
The fuel cell system according to Application Example 1, further including a flow rate adjustment valve for adjusting the amount of gas flowing into the first and second branch pipes, and a gas temperature for detecting the temperature of the measurement target gas A detection unit; and a control unit that controls the flow rate adjustment valve, wherein the control unit converts all of the measurement target gas into the first gas when the temperature detected by the temperature detection unit is within an allowable temperature range. A fuel cell system that performs a bypass process for bypassing a part or all of the measurement target gas to the second branch pipe when the detected temperature is out of the allowable temperature range when flowing into the branch pipe. .
According to this fuel cell system, part or all of the measurement target gas having a temperature outside the allowable temperature range can be bypassed to the second branch pipe. Accordingly, the load that the dew point temperature detection unit receives from the measurement target gas having a temperature outside the allowable temperature range can be reduced, so that deterioration of the sensor element for measuring the dew point temperature can be suppressed.

[Application Example 3]
In the fuel cell system according to Application Example 2, the gas pipe is a supply gas pipe connected to a supply side of the fuel cell, and the dew point temperature detection unit is the supply pipe of the fuel cell. A supply-side dew point temperature detecting unit for detecting a dew point temperature of the measurement target gas, wherein the fuel cell system is further provided in a discharge gas pipe connected to the discharge side of the fuel cell, A fourth branch pipe; and a discharge-side dew point temperature detection unit that detects a dew point temperature of the measurement target gas on the discharge side of the fuel cell flowing into the third branch pipe, and the control unit includes the supply A fuel cell system that performs characteristic evaluation for calculating an index value indicating a moisture balance in the fuel cell using a detection value of a side dew point temperature detection unit and a detection value of the discharge side dew point temperature detection unit.
According to the fuel cell evaluation system for evaluating the characteristics of the fuel cell, it is possible to reduce the load that the supply side dew point temperature detection unit and the discharge side dew point temperature detection unit receive from the measurement target gas in the fuel cell characteristic evaluation. Therefore, in the fuel cell evaluation system, it is possible to suppress deterioration of the sensor element for measuring the dew point temperature.

[Application Example 4]
The fuel cell system according to Application Example 2 or Application Example 3, wherein the measurement target gas includes a purge gas used for a purge process for purging moisture in the fuel cell system, and the control unit includes: While performing the purge process before stopping the fuel cell system, and during the purge process, regardless of the detection temperature of the temperature detection unit, if the detection value of the dew point temperature detection unit is higher than room temperature, A fuel cell that performs a bypass process for bypassing the purge gas to the second branch pipe when the purge gas is caused to flow into the first branch pipe and the detected value of the dew point temperature detection unit is not more than room temperature; system.
According to this fuel cell system, the purge process target can be switched to the second branch pipe when the purge gas flowing through the first branch pipe falls below the allowable dew point temperature. Therefore, it is possible to suppress the purge process from being performed more than necessary on the first branch pipe, and it is possible to suppress deterioration of the sensor element for measuring the dew point temperature.

[Application Example 5]
In the fuel cell system according to Application Example 3, the second supply-side dew point temperature detection unit provided in the second branch pipe and having a measurement range different from the supply-side dew point temperature detection unit, A fuel cell system comprising a second discharge side dew point temperature detection unit provided in a fourth branch pipe and having a measurement range different from that of the discharge side dew point temperature detection unit.
According to this fuel cell system, since two or more parallel measurement pipes equipped with dew point temperature detectors with different measurement ranges (measurement ranges) are provided, the measurement target gas depends on the state of the measurement target gas. It is possible to switch the measurement pipe into which the gas flows. Thereby, since the measurement object gas in a state corresponding to each dew point temperature detection unit can be appropriately supplied, the load received by the dew point meter can be reduced, and deterioration thereof can be suppressed.

[Application Example 6]
A first pipe and a second branch pipe which are provided in a gas pipe connected to the fuel cell and branch in parallel; a dew point temperature detection unit which detects a dew point temperature of the measurement target gas flowing into the first branch pipe; A method for starting a fuel cell system comprising:
(A) detecting a gas temperature of the measurement target gas;
(B) When the gas temperature is within the allowable temperature range, all of the measurement target gas is allowed to flow into the first branch pipe, and when the gas temperature is out of the allowable temperature range, the second A step of bypassing a part or all of the measurement target gas to the branch pipe;
A method for starting a fuel cell system.
According to this starting method of the fuel cell system, it is possible to suppress the supply of all the measurement target gas that is out of the allowable temperature range to the dew point temperature detecting unit at the time of starting the system. Therefore, since the load which a dew point temperature detection part receives from measurement object gas can be reduced, it can suppress that the sensor element for measuring dew point temperature deteriorates.

[Application Example 7]
A first pipe and a second branch pipe which are provided in a gas pipe connected to the fuel cell and branch in parallel; a dew point temperature detection unit which detects a dew point temperature of the measurement target gas flowing into the first branch pipe; A method for stopping a fuel cell system comprising:
(A) a step of dry purging the first branch pipe;
(B) a step of detecting a dew point temperature of a purge gas used for the dry purge in the step (a) by the dew point temperature detection unit;
(C) when the dew point temperature of the purge gas is equal to or lower than an allowable dew point temperature, a step of dry purging the second branch pipe by bypassing the purge gas to the second branch pipe;
A method for stopping the fuel cell system.
According to this fuel cell system stopping method, when the dew point temperature detected by the dew point temperature detection unit is equal to or lower than the allowable dew point temperature, the pipe that is the target of the dry purge is switched to the second branch pipe. Accordingly, it is possible to suppress the purge gas from being continuously supplied to the first branch pipe even after reaching the allowable dew point temperature, to reduce the load received by the dew point temperature detection unit by the purge gas, and to detect the dew point temperature. Can be prevented from deteriorating.

  The present invention can be realized in various forms, for example, a fuel cell system, a fuel cell evaluation system, a fuel cell system, and a fuel cell evaluation system that include a dew point measurement unit that measures the dew point temperature of gas. The present invention can be realized in the form of a control method and control apparatus, a computer program for realizing the functions of the control method or control apparatus, a recording medium on which the computer program is recorded, and the like.

A. First embodiment:
FIG. 1 is a block diagram showing the configuration of a fuel cell evaluation system as an embodiment of the present invention. FIG. 1 shows a state in which a polymer electrolyte fuel cell FC to be evaluated is connected to a fuel cell evaluation system 1000. This fuel cell evaluation system 1000 is a system that operates a fuel cell FC according to operating conditions input by a user and calculates index values indicating characteristics of the fuel cell FC from various measured values related to the operating state. The fuel cell evaluation system 1000 includes a user interface 100, an anode gas supply unit 200, a cathode gas supply unit 300, an anode exhaust gas discharge unit 400, a cathode exhaust gas discharge unit 500, and a control unit 600.

  The user interface 100 includes an input unit 110 and a display unit 120 and mediates exchange between the user and the control unit 600. The input unit 110 can be configured by a keyboard or a touch panel, for example, and accepts an input of operating conditions (described later) of the fuel cell FC from the user. The display unit 120 is configured by, for example, a monitor display, and displays measurement results regarding the characteristics of the fuel cell FC, information regarding system operation, and the like to the user according to instructions from the control unit 600.

  The anode gas supply unit 200 supplies fuel gas (hydrogen) to the fuel cell FC via a supply pipe 201 connected to the anode side of the fuel cell FC. The supply pipe 201 is provided with a fuel gas supply source 210, a humidification unit 220, a supply-side dew point measurement unit 230, and an inlet-side pressure gauge 240 from the upstream side. The fuel gas supply source 210 can be constituted by a hydrogen tank, for example, and introduces hydrogen into the supply pipe 201 in accordance with an instruction from the control unit 600. The fuel gas supply source 210 includes a regulator, a mass flow meter, a check valve, and the like (not shown), and can adjust the pressure and flow rate of the supplied hydrogen according to instructions from the control unit 600.

  The humidifying unit 220 humidifies the hydrogen supplied to the fuel cell FC according to an instruction from the control unit 600. The humidifying unit 220 is configured by a bubbler type humidifier that passes and humidifies a gas to be humidified through the hot water 221 controlled in temperature by the control unit 600. The humidification unit 220 is provided with a humidification temperature detection unit 225 that detects the temperature of the hot water 221. The humidification temperature detection unit 225 transmits the detection value to the control unit 600. In addition, the reaction gas immediately after passing through the humidification unit 220 includes a water vapor amount close to saturated water vapor with respect to the humidification temperature.

  Supply-side dew point measurement unit 230 detects an actual measurement value of the dew point temperature of the reaction gas after humidification, and transmits the detected value to control unit 600. The detailed configuration of the supply-side dew point measurement unit 230 will be described later. The inlet side pressure gauge 240 measures the pressure of hydrogen on the inlet side of the fuel cell FC and transmits the actual measurement value to the control unit 600.

  The cathode gas supply unit 300 supplies an oxidizing gas (oxygen) to the fuel cell FC via a supply pipe 301 connected to the cathode side of the fuel cell FC. An oxidant gas supply source 310, a humidification unit 320, a supply-side dew point measurement unit 330, and an inlet-side pressure gauge 340 are connected to the supply pipe 301 from the upstream side. The oxidizing gas supply source 310 is constituted by, for example, an air compressor, and introduces high-pressure air whose pressure is controlled according to an instruction from the control unit 600 into the supply pipe 301. The oxidizing gas supply source 310 includes a mass flow meter (not shown), and controls the amount of high-pressure air introduced into the pipe 301 in accordance with an instruction from the control unit 600. The humidification unit 320 has the same configuration as the humidification unit 320 of the anode gas supply unit 200, and includes hot water 321 used for humidification, and a humidification temperature detection unit 325 that detects the temperature. The supply-side dew point measurement unit 330 and the inlet-side pressure gauge 340 have the same configuration as the supply-side dew point measurement unit 230 and the inlet-side pressure gauge 240 of the anode gas supply unit 200.

  The anode exhaust gas discharge unit 400 and the cathode exhaust gas discharge unit 500 respectively emit exhaust gas containing a reaction gas that has not been supplied to the reaction via the discharge pipes 401 and 501 connected to the anode side and the cathode side of the fuel cell FC. Discharge outside the fuel cell FC. An outlet side pressure gauge 410 for measuring an actual measured value of gas pressure (back pressure) on the discharge side of the fuel cell FC, and a dew point temperature of the exhaust gas are measured from the upstream side to the discharge pipe 401 of the anode exhaust gas discharge unit 400. A discharge side dew point temperature measuring unit 420 for adjusting the pressure and a back pressure adjusting valve 430 for adjusting the back pressure in accordance with an instruction from the control unit 600 are provided. The outlet side pressure gauge 410 and the discharge side dew point measurement unit 420 transmit the measured values to the control unit 600.

  The cathode exhaust gas discharge unit 500 discharges the cathode exhaust gas containing the oxidizing gas that has not been used for the reaction via the discharge pipe 501 connected to the cathode side of the fuel cell FC to the outside of the fuel cell FC. An outlet side pressure gauge 510, a discharge side dew point temperature measurement unit 520, and a back pressure adjustment valve 530 are provided on the discharge pipe 501 of the cathode exhaust gas discharge unit 500 from the upstream side. The outlet side pressure gauge 510, the discharge side dew point temperature measurement unit 520, and the back pressure adjustment valve 530 are the same as the outlet side pressure gauge 410, the discharge side dew point temperature measurement unit 420, and the back pressure adjustment valve 430 of the anode exhaust gas discharge unit 400. Since there is, explanation is omitted.

  In this specification, a gas that circulates in the system and is a measurement target of pressure and dew point temperature in the gas supply units 200 and 300 and the exhaust gas discharge units 400 and 500 is referred to as a “measurement target gas”. In the present embodiment, the measurement target gas includes reaction gas, anode exhaust gas, and cathode exhaust gas supplied to the fuel cell FC.

  The control unit 600 can be configured by a microcomputer including a central processing unit and a main storage device. The control unit 600 controls the gas supply units 200 and 300 and the exhaust gas discharge units 400 and 500 described above according to the operating conditions input by the user via the input unit 110, and controls the reaction gas supplied to the fuel cell FC. The fuel cell FC generates power while changing the state. In addition, the control unit 600 calculates an index value indicating the characteristics of the fuel cell FC using gas state values such as the flow rate, pressure, and dew point temperature of the measurement target gas. Specifically, the control unit 600 uses the difference between the measured values of the supply-side dew point measuring units 230 and 330 and the measured values of the discharge-side dew point measuring units 420 and 520 to obtain an index value indicating the moisture balance in the fuel cell FC. Can be calculated. More specifically, for example, the amount of moisture transferred between the anode and the cathode can be calculated. Further, the control unit 600 can calculate the pressure loss of the measurement target gas in the fuel cell FC using the measured values of the inlet side pressure gauges 240 and 340 and the measured values of the outlet side pressure gauges 410 and 510. Note that the control unit 600 displays these calculation results on the display unit 120.

  An inlet side gas temperature control mechanism for controlling the temperature of the reaction gas may be provided between the fuel cell FC of the fuel cell evaluation system 1000 and the supply side dew point measurement units 230 and 330. good. Further, an exhaust gas temperature control mechanism for heating the exhaust gas may be provided between the fuel cell FC and the outlet side pressure gauges 410 and 510 in order to suppress dew condensation of water vapor contained in the exhaust gas.

  FIG. 2 is a schematic diagram illustrating the configuration of the supply-side dew point measurement unit 230 of the anode gas supply unit 200. In addition, since the structure of the other dew point measurement parts 330, 420, and 520 is the same as the structure shown in FIG. 2, description is abbreviate | omitted. The supply-side dew point measurement unit 230 includes a first branch pipe 10 and a second branch pipe 20 branched from the supply pipe 201 by the upstream three-way valve 202. The first and second branch pipes 10 and 20 are joined again to the supply pipe 201 on the downstream side by the downstream three-way valve 203.

  The first branch pipe 10 is provided with a temperature detection unit 12, a dew point meter 13, a pressure gauge 14, and a flow meter 15 from the upstream side. By the way, a pipe heater 11 is provided by winding a heating wire around the supply pipe 201 and the first branch pipe 10 on the upstream side of the dew point meter 13. The pipe heater 11 heats the measurement target gas flowing into the supply pipe 201 or the first branch pipe 10 according to an instruction from the control unit 600. The reason why the measurement target gas is heated by the pipe heater 11 will be described later. In addition, the piping heater 11 is good also as what is provided also in piping of another site | part. It is preferable that the pipe heater 11 is provided at least in the vicinity of the inlet side of the dew point meter 13.

  The temperature detection unit 12 detects an actual measurement value of the temperature of the measurement target gas in the vicinity of the dew point meter 13 heated by the pipe heater 11 and transmits the detected value to the control unit 600. The dew point meter 13 can be constituted by, for example, a polymer capacity type dew point meter. Here, the polymer capacity type dew point meter is a dew point meter in which a sensor element for measuring the dew point temperature is formed as a kind of capacitor using a polymer film as a dielectric. The polymer capacitive dew point meter measures the change in capacitance according to the wet state of the polymer film as the change in dew point temperature. The pressure gauge 14 and the flow meter 15 measure the pressure and flow rate of the measurement target gas flowing into the first branch pipe 10. The measured values of the dew point meter 13, the pressure gauge 14, and the flow meter 15 are all transmitted to the control unit 600. The measurement value of the pressure gauge 14 is used when calculating the amount of water vapor in the measurement target gas, and the measurement value of the flow meter 15 is used for controlling the flow rate of the reaction gas flowing into the measurement pipe 10. Hereinafter, the first branch pipe 10 is referred to as “measurement pipe 10”.

  The second branch pipe 20 is provided with a flow rate adjustment valve 22. The flow rate adjustment valve 22 can be configured by, for example, a ball valve. The control unit 600 controls the opening degree of the flow rate adjustment valve 22 based on the actual measurement value of the flow meter 15 of the measurement pipe 10 to flow into the first and second branch pipes 10 and 20 respectively. The ratio of the gas flow rate of the measurement target gas is controlled. In other words, the control unit 600 can bypass the first branch pipe 10 by causing a part or all of the measurement target gas supplied to the supply-side dew point measurement unit 230 to flow into the second branch pipe 20. it can. Hereinafter, the second branch pipe 20 is referred to as “bypass pipe 20”.

  3A, 3 </ b> B, and 3 </ b> C are explanatory diagrams for explaining the flow of the measurement target gas in the measurement pipe 10 and the bypass pipe 20 of the dew point measurement unit 230. 3 (A), (B), and (C) each show an arrow indicating the flow of the measurement target gas, except that the piping in which the measurement target gas is not connected is illustrated by a broken line, It is almost the same as FIG.

  FIG. 3A shows a state where a part of the measurement target gas is bypassed to the bypass pipe 20 by opening all the ports of the two three-way valves 202 and 203. Hereinafter, this state is referred to as “a state where the bypass pipe 20 is connected”. The reason for bypassing the measurement target gas in this way will be described later. On the other hand, FIG. 3B shows a state in which all of the measurement target gas flows into the measurement pipe 10 by closing the ports connected to the bypass pipes 20 of the two three-way valves 202 and 203. . Hereinafter, this state is referred to as “a state where the bypass pipe 20 is blocked”. FIG. 3C shows a state in which the connection port of the two three-way valves 202 and 203 with the measurement pipe 10 is closed and the connection port of the bypass pipe 20 is opened so that all the measurement target gas flows into the bypass pipe 20. Show. This state is referred to as “a state where the measurement pipe 10 is shut off”.

  FIG. 4 is a flowchart showing a processing procedure of the control unit 600 when the fuel cell evaluation system 1000 is activated. In this fuel cell evaluation system 1000, the system start-up process described below is executed at the time of system start-up and before executing the measurement process for evaluating the characteristics of the fuel cell FC. In the following description, the control on the supply-side dew point measuring unit 230 performed by the control unit 600 is performed on the other dew point measuring units 330, 420, and 520 in the same manner, but the description thereof is omitted.

  In step S100, the control unit 600 determines whether or not the measurement pipe 10 of the supply-side dew point measurement unit 230 is connected. When the measurement pipe 10 is connected, the control unit 600 controls the opening and closing of the ports of the two three-way valves 202 and 203 to shut off the measurement pipe 10 and the bypass pipe 20 is connected to the supply pipe 201. (Step S110: FIG. 3C). On the other hand, when the measurement pipe 10 is in a blocked state, the control unit 600 executes the process of step S120 as it is.

  In step S <b> 120, control unit 600 accepts an input of operating conditions of fuel cell FC from the user via input unit 110. In this embodiment, the flow rate of the measurement target gas, the humidification temperature of the measurement target gas in each of the humidifying units 220 and 320, and the back pressure of the measurement target gas are input and set as operating conditions of the fuel cell FC. In step S130, the control unit 600 increases the temperature of the hot water 221 and 321 (FIG. 1) of each of the humidifying units 220 and 320 and increases the temperature of the pipe heater 11 (FIG. 2) according to the input operating conditions. . In addition, it is preferable that the control part 600 controls the heating temperature by the piping heater 11 higher than the humidification temperature of the humidification parts 220 and 320. Further, in order to effectively increase the temperature of the measurement target gas, the control unit 600 preferably controls the heating temperature by the pipe heater 11 to be higher as the actual measurement value of the flow meter 15 is larger.

Here, the reason for heating the measurement target gas by the pipe heater 11 is to adjust the temperature of the measurement target gas to a suitable temperature range for dew point measurement by the pipe heater 11. When the temperature of the measurement target gas falls below its dew point temperature (humidification temperature), the water vapor contained in the measurement target gas starts to dew. In particular, when liquid water due to condensation is generated in the vicinity of the dew point meter 13, the sensor element is submerged and the dew point temperature cannot be normally measured. In addition, when liquid water due to condensation is generated in the discharge side dew point measurement units 420 and 520, there is a possibility that acidic liquid mixed in the measurement target gas inside the fuel cell FC may be included in the liquid water. The adhesion of impurities may cause deterioration of the measuring element. On the other hand, if the temperature of the measurement target gas is too high with respect to the dew point temperature, the polymer film of the dew point meter 13 may reach an extremely dry state and may be irreversibly deteriorated. Therefore, in general, the temperature Tg of the measurement target gas of the dew point meter 13 is preferably in the range of the following inequality (1) with respect to the dew point temperature Td of the measurement target gas.
Td ≦ Tg ≦ Td + 20 ° C. (1)

  In step S <b> 140, the control unit 600 detects the measurement value of the temperature detection unit 12 as the heating temperature of the measurement pipe 10 by the pipe heater 11. In addition, the control unit 600 detects the humidification temperature of the measurement target gas using the humidification temperature detection unit 225. The control unit 600 uses the actual measurement value of the temperature detection unit 12 as a predicted value of the temperature Tg of the measurement target gas when it flows into the measurement pipe 10, and uses the actual measurement value of the humidification temperature as the predicted value of the dew point temperature Td. Then, it is determined whether or not the measured value of the temperature detection unit 12 is within the allowable range indicated by the inequality (1). When the measurement value of the temperature detection unit 12 is out of the allowable range, the control unit 600 cannot sufficiently heat the measurement target gas by the pipe heater 11, and is inappropriate for starting the dew point measurement by the dew point meter 13. Judged to be temperature.

  In this case, the control unit 600 continues the process of raising the humidification temperature of the humidification unit 220 and the heating temperature of the pipe heater 11 (step S130). That is, in the processing loop of steps S130 to S140, the adjustment of the temperature and humidification temperature of the measurement target gas that passes through the dew point meter 13 is continued. During this processing loop, since the measurement target gas does not flow into the measurement pipe 10, the sensor element of the dew point meter 13 is subjected to a load by the measurement target gas having a temperature outside the range of the inequality (1). This can be suppressed.

  In addition, when the measured value of the temperature detection part 12 is lower than the lower limit value of the said allowable range, the control part 600 is good also as what performs the process which raises the heating temperature by the piping heater 11 further. Moreover, when the measured value of the temperature detection part 12 is higher than the upper limit of the said tolerance | permissible_range, the control part 600 is good also as what performs the process which reduces the heating temperature by the piping heater 11. FIG. Thereby, the temperature of the reaction gas can be adjusted more appropriately.

  If it is determined in step S140 that the measurement value of the temperature detection unit 12 is within the allowable range, the control unit 600 is in a state where the measurement pipe 10 is connected (FIG. 3A) (step S140). S150). Thereby, a part of the temperature-adjusted measurement target gas is supplied to the dew point meter 13 of the measurement pipe 10. In this state, the load that the sensor element of the dew point meter 13 receives from the measurement target gas is reduced by the amount that a part of the measurement target gas is bypassed from the measurement pipe 10 by the bypass pipe 20.

  Further, the control unit 600 detects the temperature of the measurement target gas by the temperature detection unit 12. The control unit 600 uses the measured value of the temperature of the measurement target gas as the temperature Tg of the inequality (1) and uses the measurement value of the dew point meter 13 as the dew point temperature Td, so that the temperature of the measurement target gas becomes the inequality (1). It is determined whether or not it is within the indicated allowable range (step S160). When the temperature of the measurement target gas is within the allowable range, the control unit 600 shuts off the bypass pipe 20 (FIG. 3B), and causes all the measurement target gas to flow into the measurement pipe 10 (step S170). . After executing the system activation process, the control unit 600 starts executing a measurement process for evaluating the characteristics of the fuel cell FC. On the other hand, in step S160, when the temperature of the measurement target gas is out of the allowable range, the control unit 600 applies both the measurement pipe 10 and the bypass pipe 20 until the temperature of the measurement target gas falls within the allowable range. The state where the measurement target gas flows is continued. Note that the control unit 600 adjusts the state of the measurement target gas by controlling the temperature of the pipe heater 11 and the humidification temperature of the humidifier 120 until the temperature of the measurement target gas falls within an allowable range.

  As described above, in the fuel cell evaluation system 1000 according to the present embodiment, the measurement pipe 10 is sufficiently heated by the pipe heater 11 at the time of starting the system in which the adjustment of the temperature of the measurement target gas and the dew point temperature is relatively unstable. Until then, the measurement target gas is not supplied to the dew point meter 13. Further, the supply amount of the measurement target gas to the dew point meter 13 is reduced until the temperature of the measurement target gas falls within the allowable range. Accordingly, it is possible to suppress the dew point meter 13 from being submerged in liquid water or being deteriorated due to the supply of the measurement target gas whose temperature is not within the allowable range suitable for dew point measurement. Further, since the measurement of the dew point temperature can be started when the temperature of the measurement target gas is within the allowable range, a more appropriate measurement result can be obtained.

  FIG. 5 is a flowchart showing a processing procedure of the control unit 600 when the fuel cell evaluation system 1000 is stopped. A large amount of moisture is contained in the measurement target gas flowing through the system when the fuel cell evaluation system 1000 is in operation. Therefore, when the moisture remains in the system after the system is stopped, the moisture may cause deterioration of each component such as a measuring instrument or piping in the system. Therefore, in this fuel cell evaluation system 1000, when the system is stopped, a system stop process described below is executed to suppress moisture from remaining in the system after the system is stopped. In the following description, the control on the supply-side dew point measuring unit 230 performed by the control unit 600 is performed on the other dew point measuring units 330, 420, and 520 in the same manner, but the description thereof is omitted.

  In step S210, control unit 600 stops humidification units 220 and 320 (FIG. 1). Specifically, the temperature control of the hot water 221 and 321 is stopped, the connection of the pipe to the hot water 221 and 321 is released, and the pipes 222 and 322 in the humidifying units 220 and 320 are connected. Thereby, the gas supplied to the humidification parts 220 and 320 passes through the humidification parts 220 and 320 without being humidified.

  In step S220, control unit 600 executes a dry purge process. Specifically, the purge gas whose pressure is lowered and the flow rate is increased from each of the fuel gas supply source 210 and the oxidizing gas supply source 310 to lower the pressure than the measurement target gas distributed in the system when the measurement process is executed. Purge moisture in the gas system in the system.

  The purge gas is heated by the pipe heater 11 (FIG. 2) in the dew point measuring units 230, 330, 420, and 520. By the way, the system stop process is executed after the measurement process is executed. Therefore, in this step S220, the supply-side dew point measurement unit 230 is in a state where the bypass pipe 20 is blocked (FIG. 3B), and all of the purge gas flows into the measurement pipe 10.

  In step S230, control unit 600 determines whether or not the dry purge is completed. Specifically, the dew point temperature of the purge gas is measured by the dew point meter 13 of the supply side dew point measuring unit 230. When the dew point temperature of the purge gas is higher than the room temperature, the controller 600 may cause water vapor to condense in the measurement pipe 10 when the room temperature is reached after the system is stopped, so that the dry purge process (step S220). Continue to lower the dew point temperature. On the other hand, when the dew point temperature of the purge gas is lower than the room temperature, there is almost no possibility of condensation in the room temperature state after the system is stopped, so the dry purge process is completed. That is, in this system stop process, the purge gas becomes the measurement target gas of the dew point meter 13.

  Thus, the dry purge process for the measurement pipe 10 can be reliably executed until the possibility of condensation is almost eliminated. Therefore, it is possible to suppress the dew point meter 13 from being deteriorated by liquid water generated by condensation after the system is stopped. Further, since it is determined that the possibility of condensation has almost disappeared, the dry purge process is terminated, so that it is possible to prevent the purge gas from flowing into the measurement pipe 10 after the water has been sufficiently purged. Therefore, the surplus time during which the dew point meter 13 is exposed to the heat of the purge gas can be reduced, and the possibility that the dew point meter 13 will deteriorate during the execution of the system stop process can be reduced.

  In step S230, the control unit 600 switches the pipe connection of the supply-side dew point measurement unit 230 so that the measurement pipe 10 is shut off (FIG. 3C). In step S240, the dry purge process is executed again for a predetermined time (for example, about 5 minutes). That is, in the dry purge process in step S220, the measurement pipe 10 is purged. In the dry purge process in step S240, all of the purge gas is caused to flow into the bypass pipe 20 to purge the bypass pipe 20. After the dry purge process for the bypass pipe 20 is completed, the control unit 600 stops heating by the pipe heater 11 (step S260), and puts the system in a stopped state.

  As described above, according to the fuel cell evaluation system 1000, when the system is started or stopped, all or part of the gas that causes the deterioration of the dew point meter 13 can be bypassed to the bypass pipe 20. it can. Therefore, the load on the dew point meter 13 can be reduced, and its deterioration can be suppressed.

B. Second embodiment:
FIG. 6A is a schematic diagram showing the configuration of dew point measurement units 230A, 330A, 420A, and 520A of the fuel cell evaluation system as the second embodiment of the present invention. FIG. 6A is substantially the same as FIG. 2 except that a specular dew point meter 13 </ b> A is shown instead of the polymer capacity type dew point meter 13. The overall configuration of the fuel cell evaluation system of the second embodiment is different from the dew point measuring units 230A, 330A, 420A, and 520A in place of the dew point measuring units 230, 330, 420, and 520. This is almost the same as the fuel cell evaluation system 1000 of the first embodiment (FIG. 1).

  FIG. 6B is a schematic diagram showing the configuration of the specular dew point meter 13A. The specular dew point meter 13 </ b> A includes a light emitting element 1, a light receiving element 2, a mirror 3, and a Peltier element 4. The light emitting element 1 and the light receiving element 2 are disposed so as to face the mirror 3 with the measurement space MS to which the measurement target gas is supplied interposed therebetween. More specifically, the light-emitting element 1 is arranged so that light can be emitted toward the mirror surface of the mirror 3, and the light-receiving element 2 receives the light emitted from the light-emitting element 1 reflected by the mirror surface of the mirror 3. It is arranged so that it can receive light. The mirror 3 is arranged so that its mirror surface is exposed to the reaction gas supplied to the measurement space MS. A Peltier element 4 is disposed on the surface of the mirror 3 opposite to the mirror surface. The Peltier element 4 cools the mirror 3 according to an instruction from the control unit 600. The specular dew point meter 13 </ b> A optically detects, by the light emitting element 1 and the light receiving element 2, that water vapor in the measurement target gas is condensed on the mirror surface of the mirror 3 cooled by the Peltier element 4. Then, the mirror surface temperature of the mirror 3 at that time is detected as the dew point temperature of the measurement target gas.

  By the way, when measuring using the specular dew point meter 13A, if the temperature of the measurement target gas is lower than the dew point temperature, the gas is the same as the polymer capacity type dew point meter 13 described in the first embodiment. It may be submerged by liquid water generated by condensation of water vapor inside. When the temperature of the measurement target gas is too high (for example, 150 ° C. or higher), the Peltier element 4 continues to operate at a high output to cool the mirror 3, and the specular dew point meter 13A deteriorates. There is a possibility of promoting. Therefore, in the fuel cell evaluation system of the second embodiment, a system activation process that can reduce the load on the specular dew point meter 13A is executed at the time of system activation in which the temperature control of the measurement target gas is generally unstable.

  FIG. 7 is a flowchart showing a processing procedure of system activation processing in the fuel cell evaluation system of the second embodiment. FIG. 7 is a diagram except that steps S111, S112, and S114 are added instead of steps S100 and S110, and steps S142, S144, and S146 are added instead of steps S150 and S160. The same as 4. In the following description, the control on the supply-side dew point measuring unit 230A executed by the control unit 600 is similarly executed on the other dew point measuring units 330A, 420A, and 520A, but the description thereof is omitted.

  In step S <b> 111, the control unit 600 sets the supply pipe dew point measurement unit 230 </ b> A of the bypass pipe 20 to the supply pipe 201, and allows the measurement target gas to flow into the measurement pipe 10 and the bypass pipe 20. (FIG. 3A). The controller 600 confirms the operating state of the Peltier element 4 in step S112, and stops it if it is in the operating state (step S114). In step S120, the input of the operating condition of the fuel cell FC is received from the user, and the heating of the humidifying temperature of the pipe heater 11 and the humidifying units 220 and 320 is started according to the operating condition (step S130).

  After continuing the temperature raising process for a predetermined time (for example, about 10 minutes) in step S130, the control unit 600 uses the measurement value of the humidification temperature detection unit 225 as the predicted value of the dew point temperature of the measurement target gas in step S140. Thus, it is determined whether or not the temperature detected by the temperature detector 12 is within the allowable range (inequality (1)) described in the first embodiment. When the measured value of the temperature detection unit 12 is out of the allowable range, it is assumed that the heating of the measurement pipe 10 by the pipe heater 11 is not sufficient, and the humidification temperature of the humidification units 220 and 320 and the temperature increase process of the pipe heater 11 (Step S130).

  On the other hand, when the measured value of the temperature detection unit 12 is within the allowable range, the control unit 600 activates the Peltier element 4 to measure the dew point temperature of the measurement target gas at the current time (step S142). When the dew point temperature of the measurement target gas has not reached the target value of the dew point temperature set according to the operating condition input by the user, the control unit 600 stops the operation of the Peltier element 4 (step S146). . And in step S130, the humidification temperature of the humidification parts 220 and 320 and the temperature rising process of the piping heater 11 are continued, and the dew point temperature of measurement object gas is raised. That is, by stopping the operation of the Peltier element 4 in step S146, it is possible to avoid the Peltier element 4 from continuing excessive cooling operation according to the temperature rise of the measurement target gas in step S130.

  If the temperature of the measurement target gas is within the allowable range in step S140 and the dew point temperature of the measurement target gas has reached the target value in step S144, the control unit 600 connects the piping in step S170. Switch. That is, the control part 600 makes the bypass piping 20 of the supply side dew point measurement part 230A shut off (FIG. 3 (B)). As a result, all of the measurement target gas can flow into the measurement pipe 10. Thereafter, the control unit 600 starts measurement processing by the fuel cell evaluation system.

  As described above, according to the system start-up process in the fuel cell evaluation apparatus of the second embodiment, the operation of the Peltier element 4 is stopped when the heating of the measurement target gas by the pipe heater 11 is insufficient or excessive. To do. The operation of the Peltier element 4 is also stopped when the measurement target gas has not reached the target dew point temperature. Therefore, it is possible to suppress the deterioration of the specular dew point meter 13 </ b> A due to the Peltier element 4 continuing to operate excessively according to the heating temperature by the pipe heater 11. Moreover, when the temperature of measurement object gas is remarkably low compared with dew point temperature, it can suppress that the mirror 3 is submerged by liquid water by the Peltier device 4 operating.

  By the way, also in the fuel cell evaluation system of the second embodiment, as in the fuel cell evaluation system 1000 of the first embodiment, the dry purge process is executed so that excess moisture does not remain in the gas system of the system after the system is stopped. To do. However, when the mirror 3 of the specular dew point meter 13A is exposed to a high temperature (for example, 100 ° C. or more) purge gas for a long time with the Peltier element 4 in an activated state, the load on the Peltier element 4 increases and the deterioration There is a possibility of promoting. Therefore, in the fuel cell evaluation system of the second embodiment, the system stop process described below is executed when the system is stopped.

  FIG. 8 is a flowchart showing a processing procedure of a system stop process executed when the fuel cell evaluation system of the second embodiment is stopped. FIG. 8 is substantially the same as FIG. 5 except that steps S212, S214, S222, S224, and S235 are added. In the following description, the control on the supply-side dew point measuring unit 230A executed by the control unit 600 is similarly executed on the other dew point measuring units 330A, 420A, and 520A, but the description thereof is omitted.

  The control unit 600 stops driving the humidifying units 220 and 320 in step S210. Further, the control unit 600 stops the operation of the Peltier element 4 in steps S212 and S214 in the same procedure as described in steps S112 and S114 of FIG. In step S220, control unit 600 executes a dry purge process. In the dry purge process in step S220, the bypass pipe 20 of the supply-side dew point measurement unit 230A is shut off, and the dry purge process is performed on the measurement pipe 10. Thus, since purge gas is supplied to the specular dew point meter 13A with the operation of the Peltier element 4 stopped, the load on the Peltier element 4 due to the purge gas is reduced, and deterioration of the specular dew point meter 13A is suppressed.

  The controller 600 continues the dry purge process in step S220 for a predetermined time (for example, about 10 minutes). Thereafter, the control unit 600 executes a process for determining the completion of the dry purge process for the measurement pipe 10 in steps S222 to S230. Specifically, the control unit 600 reduces the temperature of the pipe heater 11 to a predetermined temperature (for example, about 50 ° C.) in step S222, and activates the Peltier element 4 in step S224. The reason why the temperature of the pipe heater 11 is reduced in step S222 is to reduce the load on the Peltier element 4 by reducing the temperature of the purge gas. In step S240, the control unit 600 causes the specular dew point meter 13A to detect the dew point temperature of the purge gas, and when the detected dew point temperature of the purge gas is equal to or lower than room temperature, the dry purge process for the measurement pipe 10 is completed. judge.

  When it is determined in step S230 that the dry purge process has been completed, the control unit 600 executes the dry purge process for the bypass pipe 20 in steps S240 and S250. After the dry purge process for the bypass pipe 20, the control unit 600 stops heating the pipe heater 11 (step S260) and stops the entire fuel cell evaluation system. On the other hand, when it is determined in step S230 that the dry purge process for the measurement pipe 10 has not been completed, the control unit 600 raises the temperature of the pipe heater 11 again to the temperature at which the dry purge process is performed. (Step S235), the operation of the Peltier element 4 is stopped (Step S214), and the dry purge process for the measurement pipe 10 is restarted (Step S220).

  According to this system stop process, similarly to the first embodiment, the completion of the dry purge process for the measurement pipe 10 provided with the specular dew point meter 13A is determined by measuring the dew point temperature of the purge gas. Therefore, as in the first embodiment, the surplus time during which purge gas is supplied to the measurement pipe 10 can be reduced, and the load on the specular dew point meter 13A due to the purge gas is reduced. Moreover, since the operation of the Peltier element 4 of the specular dew point meter 13A is stopped except when the dry purge process completion determination process is executed, the Peltier element 4 is prevented from operating at a high output according to the temperature of the purge gas. Can be suppressed.

  As described above, according to the fuel cell evaluation system of the second embodiment, when the system is activated, the temperature of the measurement target gas is out of the allowable range, or the measurement target gas has not reached the target dew point temperature. In this case, it is possible to suppress the Peltier element 4 from operating more than necessary. Therefore, deterioration of the specular dew point meter 13A due to overload can be suppressed. Further, since the operation of the Peltier element 4 is appropriately controlled even when the dry purge process is executed, the deterioration of the specular dew point meter 13A can be suppressed.

C. Third embodiment:
FIG. 9 is a schematic diagram showing the configuration of the dew point measurement units 230B, 330B, 420B, and 520B of the fuel cell evaluation system as the third embodiment of the present invention. FIG. 9 is substantially the same as FIG. 2 except that a second bypass pipe 30 is added. Hereinafter, the bypass pipe 20 described in the above embodiment is referred to as a “first bypass pipe 20” for convenience. In the following, the supply-side dew point measurement unit 230B will be described, but the same applies to the other dew point measurement units 330B, 420B, and 520B, and the description thereof will be omitted. The overall configuration of the fuel cell evaluation system of the third embodiment is different from the dew point measurement units 220, 320, 420, and 520 except that the dew point measurement units 230B, 330B, 420B, and 520B are used. This is the same as the first embodiment (FIG. 1).

  The second bypass pipe 30 branches from the supply pipe 201 by two three-way valves 202 and 203 and is connected in parallel with the measurement pipe 10 and the first bypass pipe 20. That is, in the supply-side dew point measurement unit 230B, the measurement pipe 10 and the first and second bypass pipes 20 and 30 are respectively provided with three-way valves 202 and 30 provided in the first and second bypass pipes 20 and 30, respectively. 203 are connected to each other. The pipe heater 11 is provided in a pipe from the supply pipe 201 upstream of the dew point meter 13 to the inlet of the dew point meter 13. With this configuration, the supply-side dew point measurement unit 230B can realize various pipe connection modes.

  FIGS. 10A, 10 </ b> B, 10 </ b> C, and 10 </ b> D are explanatory diagrams for explaining an example of connection modes of the pipes 10, 20, and 30 of the supply-side dew point measurement unit 230 </ b> B. 10 (A), (B), (C), and (D) each show an arrow indicating the flow of the measurement target gas, and a broken line indicates a pipe that is not connected to the measurement target gas. Except for the point, it is almost the same as FIG.

  FIG. 10A shows a state in which the second bypass pipe 30 is blocked and the measurement pipe 10 and the first bypass pipe 20 are connected to the supply pipe 201. FIG. 10B shows a state in which the measurement pipe 10 and the first bypass pipe 20 are shut off and the second bypass pipe 30 is connected to the supply pipe 201. FIG. 10C shows a state in which the measurement pipe 10 and the second bypass pipe 30 are disconnected and only the first bypass pipe 20 is connected to the supply pipe 201. FIG. 10D shows a state in which only the measurement pipe 10 is connected to the supply pipe 201 and the first and second bypass pipes 20 and 30 are blocked.

  The control unit 600 executes the measurement process of the fuel cell evaluation system in the pipe connection mode shown in FIG. In this pipe connection mode, the amount of gas flowing through the measurement pipe 10 can be controlled by the flow rate adjustment valve 22 of the first bypass pipe 20. That is, the first bypass pipe 20 functions as a flow rate adjusting pipe for adjusting the flow rate of the measurement target gas to the measurement pipe 10 in the measurement process for evaluating the characteristics of the fuel cell FC. The control unit 600 can execute the measurement process of the dew point temperature while reducing the load that the dew point meter 13 receives from the measurement target gas by adjusting the flow rate of the measurement target gas supplied to the measurement pipe 10. .

  Further, in this fuel cell evaluation system, at the time of system startup, processing similar to the system startup processing described in the first embodiment is executed (FIG. 4). Specifically, in steps S100 to S140, the control unit 600 shuts off the measurement pipe 10 and the first bypass pipe 20, and causes the measurement target gas to flow into the second bypass pipe 30 to execute each processing step. To do. That is, steps S100 to S140 are executed in the pipe connection mode of FIG. And in step S150, the 2nd bypass piping 30 is interrupted | blocked and it switches to the piping connection aspect shown to FIG. 10 (A). That is, in this case, the measurement pipe 10 and the first bypass pipe 20 function as a measurement pipe used for measurement in the measurement process, and the second bypass pipe 30 functions as a bypass pipe for the measurement pipe. Can be interpreted. Thereafter, in step S170, the pipe connection mode in FIG. 10A is switched to the pipe connection mode in FIG. As a result, the measurement process is started in a state where all the measurement target gases have flowed into the measurement pipe 10.

  Further, in this fuel cell evaluation system, when the system is stopped, the same process as the dry purge process (FIG. 5; steps S220 and S250) in the system stop process described in the first embodiment is executed. Specifically, by switching the pipe connection modes shown in FIGS. 10B to 10D in order, each pipe in the order of the second bypass 30, the second bypass pipe 20, and the measurement pipe 10. The dry purge process is executed every 10, 20, and 30. When the dry purge process is performed on the measurement pipe 10, the completion determination process for the dry purge process similar to step S230 in FIG. 5 is performed.

  As described above, by providing two or more bypass pipes in parallel with the measurement pipe 10 as in the first and second bypass pipes 20 and 30, the amount of gas supplied to the dew point meter 13 of the measurement pipe 10. Can be controlled more appropriately. Therefore, the deterioration of the dew point meter 13 can be further suppressed.

D. Fourth embodiment:
FIG. 11 is a schematic diagram showing the configuration of the dew point measuring units 230C, 330C, 420C, and 520C of the fuel cell evaluation system as the fourth embodiment of the present invention. FIG. 11 is substantially the same as FIG. 9 except that a second measurement pipe 40 is added between the first bypass pipe 20 and the second bypass pipe 30. Hereinafter, the measurement pipe 10 described in the above embodiment is referred to as a “first measurement pipe 10” for convenience. In the following, the supply-side dew point measurement unit 230C will be described, but the same applies to the other dew point measurement units 330C, 420C, and 520C, and the description thereof will be omitted. The overall configuration of the fuel cell evaluation system of the third embodiment is different from the dew point measurement units 220, 320, 420, and 520 except that the dew point measurement units 230B, 330B, 420B, and 520B are used. This is the same as the first embodiment (FIG. 1).

  Similar to the first measurement pipe 10 and the first and second bypass pipes 20 and 30, the second measurement pipe 40 is a pipe branched from the supply pipe 201. Specifically, the first and second bypass pipes 20 and 30 are connected by three-way valves 202 and 203. The second measurement pipe 40 is the same as the first measurement pipe 10 except that the dew point meter 13C is provided instead of the dew point meter 13 and the flow meter 15 is not provided. The pipe heater 11 is also provided up to the inlet of the dew point meter 13 </ b> C in the second measurement pipe 40, similarly to the first measurement pipe 10.

  Here, the dew point meter 13 of the first measurement pipe 10 and the dew point meter 13C of the second measurement pipe 40 are dew point meters having different measurement ranges. Specifically, the dew point meter 13 of the first measurement pipe 10 can cope with the measurement of a dew point temperature at a high temperature (70 ° C. or higher), and the dew point meter 13C of the second measurement pipe 40 is a low temperature (for example, 90 ° C.). It can be used for measurement of dew point temperature of ℃ or less. Hereinafter, the dew point meter 13 of the first measurement pipe 10 is referred to as “high dew point measurement dew point meter 13”, and the dew point meter 13C of the second measurement pipe 40 is referred to as “low dew point measurement dew point meter 13C”. Call.

  FIGS. 12A and 12B are explanatory diagrams for explaining a pipe connection mode in the supply-side dew point measurement unit 230C. FIGS. 12A and 12B are substantially the same as FIG. 11 except that an arrow indicating the flow of the measurement target gas is shown, and that the piping through which the measurement target gas is not connected is indicated by a broken line. It is.

  FIG. 12A is a pipe connection mode when the dew point temperature of the measurement target gas is low, and FIG. 12B is a pipe connection mode when the dew point temperature of the measurement target gas is high. That is, the control unit 600 connects the supply-side dew point measurement unit 230C to the pipe connection at the time of low dew point temperature measurement shown in FIG. 12A until the dew point temperature of the measurement target gas reaches an allowable dew point temperature (for example, 80 ° C.). Let it be an aspect. In addition, when the dew point temperature of the measurement target gas reaches the allowable dew point temperature and becomes high, the control unit 600 causes the supply side dew point measurement unit 230C to perform the high dew point temperature measurement shown in FIG. Switch to pipe connection mode. In FIG. 12A, the first bypass pipe 20 functions as a flow rate adjustment pipe that adjusts the flow rate of the measurement target gas with respect to the second measurement pipe 40. On the other hand, in FIG. 12B, the first bypass pipe 20 functions as a flow rate adjustment pipe that adjusts the flow rate of the measurement target gas with respect to the first measurement pipe 10.

  In this fuel cell evaluation system, at the time of system startup, the same process as the system startup process described in the first embodiment is executed (FIG. 4). However, the control unit 600 shuts off the first measurement pipe 10 at the beginning of the system startup, and the second measurement pipe 40 and the first and second bypass pipes 20 and 30 are connected. In the state, steps S100 to S140 are executed. And the control part 600 interrupts | blocks the 2nd piping 40 for a measurement, when the measured value of the humidification temperature in the humidification parts 220 and 320 reaches | attains 80 degreeC in the processing loop of step S130-S140, and the 1st The measurement pipe 10 is connected. When the temperature of the pipe heater 11 is within the allowable range, the control unit 600 shuts off the second bypass pipe 30 and proceeds to a measurement process for evaluating the characteristics of the fuel cell FC.

  In this fuel cell evaluation system, when the system is stopped, processing similar to the dry purge processing (FIG. 5; steps S220 and S250) in the system stopping processing described in the first embodiment is executed. Specifically, the dry purge process is performed for each of the pipes 10, 20, 30, and 40 in the order of the second bypass 30, the second bypass pipe 20, the second measurement pipe 40, and the first measurement pipe 10. Is executed. When the dry purge process is performed on the first and second measurement pipes 10 and 40, the dry purge process completion determination process similar to step S230 in FIG. 5 is performed.

  As described above, in the fuel cell evaluation system of the fourth embodiment, two or more parallel measurement pipes having dew point meters with different measurement ranges are provided in the dew point measurement unit, and each dew point temperature depends on the dew point temperature of the measurement target gas. Switch the connection of the measurement pipe. Thereby, since the measurement object gas in a state corresponding to the measurement range of each dew point meter can be appropriately supplied, the load on the dew point meter can be reduced, and deterioration thereof can be suppressed.

E. Variations:
In addition, this invention is not restricted to said Example and embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects. For example, the fuel cell evaluation system can be implemented as a fuel cell evaluation device. In addition, the following modifications are possible.

E1. Modification 1:
In the above embodiment, the fuel cell FC that is the object of evaluation of the fuel cell evaluation system is a solid polymer fuel cell, but other types of fuel cells may be evaluated.

E2. Modification 2:
In the above embodiment, the fuel cell evaluation system 1000 includes the measurement pipe 10 and the bypass pipe 20. However, the measurement pipe 10 and the bypass pipe 20 may be provided in another fuel cell system including a fuel cell other than the fuel cell evaluation system. For example, it may be used in a fuel cell system that operates a fuel cell while controlling the dew point temperature of the reaction gas supplied to the fuel cell.

E3. Modification 3:
In the above embodiment, the pressure gauge 14 and the flow meter 15 provided in the measurement pipe 10 and the flow rate adjustment valve 22 provided in the bypass pipe may be omitted. Moreover, in the said Example, the control which interrupts | blocks either the piping 10 for a measurement or the bypass piping 20 with the three-way valve 202,203 at the time of a system starting and a system stop was performed. However, without performing such control, control may be performed so that gas is conducted to both the measurement pipe 10 and the bypass pipe 20 at all times when the system is started and stopped. Even with such a configuration, the flow rate of the gas supplied to the dew point meter 13 can be reduced when the system is started up and when the dry purge process is executed, so that deterioration of the dew point meter 13 can be suppressed.

E4. Modification 4:
In the above embodiment, the control unit 600 causes a part or all of the measurement target gas to flow through the bypass pipe when the temperature of the measurement target gas (including the dew point temperature) is out of the allowable range at the time of system startup and system shutdown. The bypass process was being executed. However, the bypass process may be executed other than when the system is started or when the system is stopped. For example, when the temperature of the measurement target gas deviates from a preset allowable range for some reason during the execution of the measurement process, the measurement process is stopped, the bypass process is executed, and an overload on the dew point meter 13 is avoided. It is good to do.

E5. Modification 5:
In the above embodiment, the dew point temperature measuring units 220, 320, 420, and 520 including the measurement pipe 10 and the bypass pipe 20 are provided for each of the pipes 201, 301, 401, and 501 connected to the fuel cell FC. It was. However, the dew point temperature measurement unit including branch pipes such as the measurement pipe 10 and the bypass pipe 20 need not be provided in all the pipes 201, 301, 401, 501, for example, the supply side pipe 201. , 301 may be provided only for.

E6. Modification 6:
In the system start-up process of the first embodiment, the allowable temperature range of the measurement target gas is set to the range indicated by the inequality (1). However, the allowable range may be set in a wider range or narrow. It may be set to a range. Further, the allowable temperature range of the measurement target gas may be set without using the predicted dew point temperature.

E7. Modification 7:
In the system stop process of the first embodiment, the control unit 600 has completed the dry purge process when the dew point temperature of the purge gas is below room temperature. However, the dry purge process completion conditions may be other conditions. For example, the control unit 600 may complete the dry purge process when the dew point temperature is 10 ° C. or lower.

E8. Modification 8:
In the system stop process of the first embodiment, the control unit 600 detects the temperature of the purge gas flowing in the measurement pipe 10 by the temperature detection unit 12, and controls the purge gas temperature to be within the allowable range. Also good. This can reduce the load that the dew point meter 13 receives from the purge gas when the dry purge process is executed.

E9. Modification 9:
In the first embodiment, a part of the measurement target gas flowing into the measurement pipe 10 is bypassed to the bypass pipe 20 (FIG. 4; steps S150 to S160). However, the steps S150 to S160 may be omitted, and all the measurement target gases may be flowed into the measurement pipe 10 after step S140.

E10. Modification 10:
In the second embodiment, the connection switching process for the measurement pipe 10 or the bypass pipe 20 is executed in steps S111 and S170. However, step S111 and step S170 need not be executed, and the operation control of the Peltier element 4 (steps S114, S140, S146) is executed in a state where all the measurement target gas flows into the measurement pipe 10. Also good. However, by bypassing a part of the measurement target gas to the bypass pipe 20, the load received by the specular dew point meter 13 </ b> A from the measurement target gas can be reduced. Therefore, it is preferable to execute the processing procedure of the second embodiment. .

Schematic which shows the structure of a fuel cell evaluation system. Schematic which shows the structure of a dew point measurement part. Explanatory drawing for demonstrating the flow of the gas in a dew point measurement part. The flowchart which shows the process sequence of the starting process of the fuel cell evaluation system in 1st Example. The flowchart which shows the process sequence of the stop process of the fuel cell evaluation system in 1st Example. Schematic which shows the structure of the mirror surface type dew point meter in 2nd Example. The flowchart which shows the process sequence of the starting process of the fuel cell evaluation system in 2nd Example. The flowchart which shows the process sequence of the stop process of the fuel cell evaluation system in 2nd Example. Schematic which shows the structure of the dew point measurement part in 3rd Example. Schematic which shows the example of the piping connection aspect of the dew point measurement part in 3rd Example. Schematic which shows the structure of the dew point measurement part in 4th Example. Schematic for demonstrating the pipe connection aspect of the dew point measurement part in 4th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light emitting element 2 ... Light receiving element 3 ... Mirror 4 ... Peltier element 10 ... Measurement piping (1st branch piping)
11 ... Piping heater 12 ... Temperature detector 13 ... Dew point meter (dew point meter for high dew point measurement)
13A ... Mirror surface type dew point meter 13C ... Low dew point measurement dew point meter 14 ... Pressure gauge 15 ... Flow meter 20 ... Bypass piping (second branch piping, first bypass piping)
DESCRIPTION OF SYMBOLS 22 ... Flow control valve 30 ... 2nd bypass piping 40 ... 2nd measurement piping 100 ... User interface 110 ... Input part 120 ... Display part 200 ... Anode gas supply part 202 ... Upstream three-way valve 203 ... Downstream three-way valve 210 ... Fuel gas supply source 300 ... Cathode gas supply unit 310 ... Oxidation gas supply source 201, 301 ... Supply piping 220, 320 ... Humidification unit 221, 321 ... Hot water 222, 322 ... Piping 225, 325 ... Humidity temperature detection unit 230, 330, 230A, 330A, 230B, 330B, 220C, 330C ... supply side dew point measurement unit 240, 340 ... inlet side pressure gauge 400, 500 ... exhaust gas discharge part 401, 501 ... discharge pipe 410, 510 ... outlet side pressure gauge 420, 520, 420A, 520A, 420B, 520B, 420C, 520C ... discharge side Dew point measurement unit 430, 530 ... back pressure regulating valve 500 ... cathode exhaust gas discharge unit 600 ... control unit 1000 ... fuel cell evaluation system FC ... fuel cell MS ... measurement space

Claims (6)

A fuel cell system,
A first branch pipe and a second branch pipe provided in a gas pipe connected to the fuel cell and branched in parallel;
A dew point temperature detection unit for detecting a dew point temperature of the measurement target gas flowing into the first branch pipe;
A flow rate adjusting valve for adjusting the amount of gas flowing into the first and second branch pipes;
A gas temperature detector for detecting the temperature of the measurement target gas;
A control unit for controlling the flow regulating valve;
With
The second branch pipe functions as a bypass pipe for bypassing part or all of the measurement target gas from the first branch pipe .
When the temperature detected by the temperature detection unit is within an allowable temperature range, the control unit causes all of the measurement target gas to flow into the first branch pipe, and the detected temperature deviates from the allowable temperature range. If there is, a bypass process for bypassing part or all of the measurement target gas to the second branch pipe is performed,
The allowable temperature range is a temperature range set in advance so as to be equal to or higher than a temperature at which water vapor contained in the measurement target gas starts dew condensation and equal to or lower than a temperature causing deterioration due to heat in the dew point temperature detection unit . Fuel cell system. The fuel cell system according to claim 1 ,
The gas pipe is a supply gas pipe connected to the supply side of the fuel cell,
The dew point temperature detection unit is a supply side dew point temperature detection unit that detects a dew point temperature of the measurement target gas on the supply side of the fuel cell,
The fuel cell system further includes:
A third and a fourth branch pipe provided in a discharge gas pipe connected to the discharge side of the fuel cell;
A discharge-side dew point temperature detection unit for detecting a dew point temperature of the measurement target gas on the discharge side of the fuel cell flowing into the third branch pipe;
With
The control unit performs a characteristic evaluation for calculating an index value indicating a moisture balance in the fuel cell using a detection value of the supply side dew point temperature detection unit and a detection value of the discharge side dew point temperature detection unit. Fuel cell system. The fuel cell system according to claim 1 or 2 , wherein
The measurement target gas includes a purge gas used for a purge process for purging moisture in the fuel cell system,
The control unit executes the purge process before the fuel cell system is stopped, and at the time of the purge process, the detection value of the dew point temperature detection unit is a room temperature regardless of the detection temperature of the temperature detection unit. If higher, the purge gas is allowed to flow into the first branch pipe, and when the detected value of the dew point temperature detection unit is not more than room temperature, the purge gas is bypassed to the second branch pipe. Run the fuel cell system. The fuel cell system according to claim 2 , further comprising:
A second supply-side dew point temperature detection unit provided in the second branch pipe and having a measurement range different from the supply-side dew point temperature detection unit;
A second discharge side dew point temperature detection unit provided in the fourth branch pipe and having a measurement range different from the discharge side dew point temperature detection unit;
A fuel cell system comprising: A first pipe and a second branch pipe which are provided in a gas pipe connected to the fuel cell and branch in parallel; a dew point temperature detection unit which detects a dew point temperature of the measurement target gas flowing into the first branch pipe; A method for starting a fuel cell system comprising:
(A) detecting a gas temperature of the measurement target gas;
(B) When the gas temperature is within the allowable temperature range, all of the measurement target gas is allowed to flow into the first branch pipe, and when the gas temperature is out of the allowable temperature range, the second A step of bypassing a part or all of the measurement target gas to the branch pipe;
Equipped with a,
The allowable temperature range is a temperature range set in advance so as to be equal to or higher than a temperature at which water vapor contained in the measurement target gas starts dew condensation and equal to or lower than a temperature causing deterioration due to heat in the dew point temperature detection unit . How to start a fuel cell system. A first pipe and a second branch pipe which are provided in a gas pipe connected to the fuel cell and branch in parallel; a dew point temperature detection unit which detects a dew point temperature of the measurement target gas flowing into the first branch pipe; A method for stopping a fuel cell system comprising:
(A) a step of dry purging the first branch pipe;
(B) a step of detecting a dew point temperature of a purge gas used for the dry purge in the step (a) by the dew point temperature detection unit;
(C) when the dew point temperature of the purge gas is equal to or lower than an allowable dew point temperature, a step of dry purging the second branch pipe by bypassing the purge gas to the second branch pipe;
A method for stopping the fuel cell system.

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